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108 Cards in this Set
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90Sr THERAPY FOR ORAL SQUAMOUS CELL CARCINOMA IN TWO CATS
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• Two cats with a superficial oral squamous cell carcinoma responded favorably to treatment using a 90Sr probe. • From one to six fields were applied per tumor, depending on tumor size. The surface dose per treatment ranged from 75 to 150 Gy and the total surface dose ranged from 200 to 500 Gy. • Adverse effects were minimal. The cats survived 7 months and 5 years 9 months from the time of diagnosis. • These data indicate that with careful patient selection 90Sr may be useful for the treatment of feline oral squamous cell carcinoma in some patients. |
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CLINICAL SIGNIFICANCE OF RENAL PELVIC DILATATION ON ULTRASOUND IN DOGS AND CATS |
• clinically normal renal function, and (II) clinically normal renal function with diuresis; (III) pyelonephritis; (IV) noninfectious renal insufficiency; (V) outflow obstruction; (VI) miscellaneous nonobstructive anomalies. • Pelvic width in group I was lower than in groups III–V (P1⁄40.0001),but did not significantly differ from group II. Pelvic width 13mm always indicated obstruction. • These results confirm that renal pelvic dilatation can be detected sonographically in dogs and cats with clinically normal renal function, and that it increases with renal insufficiency, pyelonephritis, or outflow obstruction. Nevertheless, renal pelvic width varies substantially within groups and should be interpreted with caution. |
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CLINICAL, PATHOLOGIC, AND MAGNETIC RESONANCE IMAGING CHARACTERISTICS OF CANINE DISC EXTRUSION ACCOMPANIED BY EPIDURAL HEMORRHAGE OR INFLAMMATION |
• Disc extrusion causing epidural hemorrhage or inflammation is more common in the caudal aspect of the lumbar spine than disc extrusions that do not cause signs of hemorrhage or inflammation (Po0.05) in MR images. • The appearance of the lesion created by disc extrusion with epidural hemorrhage and inflammation encompasses a wide variety of imaging features, likely related to the duration of the hemorrhage and associated inflammatory changes. In 10 of 46 dogs these secondary changes masked identification of the disc extrusion itself in the MR images. • The prognosis of dogs with disc extrusion accompanied by hemorrhage or inflammation does not appear to be different than for dogs with disc extrusion and without imaging signs of epidural hemorrhage or inflammation. |
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COMPARATIVE MAGNETIC RESONANCE IMAGING FINDINGS BETWEEN GLIOMAS AND PRESUMED CEREBROVASCULAR ACCIDENTS IN DOGS |
• Gliomas were predominantly located in the cerebrum (76%) compared with presumed cerebrovascular accidents that were located mainly in the cerebellum, thalamus, caudate nucleus, midbrain, and brainstem (76%). • Gliomas were significantly larger compared with presumed cerebrovascular accidents and more commonly associated with mass effect and perilesional edema. • Wedge-shaped lesions were seen only in 19% of presumed cerebrovascular accidents. Diffusion weighted imaging increased the accuracy of the diagnosis for both lesions. |
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COMPUTED TOMOGRAPHIC CHARACTERISTICS OF INTRAPELVIC MASSES IN DOGS |
• The CT images of 14 dogs with a histopathologically confirmed intrapelvic mass were evaluated. Postcontrast internal heterogeneity of the mass was the only characteristic significantly associated with malignancy |
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CONTRAST ENHANCEMENT OF EXTRADURAL COMPRESSIVE MATERIAL ON MAGNETIC RESONANCE IMAGING |
• Images were evaluated for lesion location, type of herniation, degree of compression, intramedullary T2-weighted (T2W) intensities, and contrast enhancement. • Contrast enhancement of extradural compressive material, meninges, and both the compressive materials and meninges was present in 51.5%, 39.4%, and 17.2% of lesions, respectively. • Extradural enhancement occurred more frequently in extrusions than protrusions (P1⁄40.001). Meningeal enhancement and more severe neurologic deficits were significantly associated with a shorter duration of clinical signs |
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CONTRAST-ENHANCED ULTRASOUND OF THE NORMAL CANINE PROSTATE GLAND |
• We characterized the ultrasonographic appearance of prostate gland vascularity in 10 healthy dogs before and after the injection of an ultrasound contrast agent (Levovistt). • Before injecting Levovistt, the prostate gland blood flow was classified as poor in all dogs, whereas after contrast agent injection blood flow was classified as moderate or good, in 3 and 7 dogs respectively. |
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DISPLAY QUALITY OF DIFFERENT MONITORS IN FELINE DIGITAL RADIOGRAPHY |
• The two medical-grade monitors had superior display quality compared with standard PC monitors. No differences were seen between the monochrome monitors. In comparison with the color CRT, the ratings of the color LCD were significantly worse. |
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DOES CHANGING THE ORIENTATION OF A THORACIC RADIOGRAPH AID DIAGNOSIS OF RIB FRACTURES? |
• Sensitivity for rib fractures was 53–69% and specificity was 74–97%, depending on the observer. Radiologists had higher spec- ificity than less experienced observers (P 1⁄4 0.0001), but comparable sensitivity for rib fractures. Radiologists had significantly higher accuracy than residents (P 1⁄4 0.03), and residents had higher accuracy than interns • Rotating radiographs 901 clockwise was associated with increased specificity of one intern (from 74 to 90%, P 1⁄4 0.03), but had no effect on accuracy of diagnosis by other observers |
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IMAGING DIAGNOSIS—CONGENITAL LOBAR EMPHYSEMA IN A DOG |
• Computed tomography confirmed the presence of the emphysematous lobe and further showed it to have focal lobar bronchial collapse. Lung lobe resection was performed, and the diagnosis was congenital lobar emphysema secondary to bronchial cartilage hypoplasia. |
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IMAGING DIAGNOSIS—TRANSCRANIAL COLOR-CODED DUPLEX SONOGRAPHY IN A DOG WITH HEPATIC ENCEPHALOPATHY |
• A severe increase in the pulsatility index was measured in the right middle cerebral artery, left middle cerebral artery, and basilar artery. These values returned to normal following medical stabilization of the patient and resolution of the neurologic signs |
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MAGNETIC RESONANCE IMAGING OF THE CANINE BRAIN AT 3 AND 7 T |
• Low-resolution turbo spin echo (TSE) T2-weighted images (T2W) were obtained in transverse, dorsal, and sagittal planes, and high-resolution TSE T2W and turbo spin echo proton density-weighted images were obtained in the transverse and dorsal planes, at both 3 and 7T. • Overall, 19 of the 32 neuroanatomic structures had comparable spatial resolution and contrast at both field strengths. The overall image quality for low-resolution T2W images was comparable at 3 and 7T. • High-resolution T2W was characterized by superior image quality at 3 vs. 7T. Magnetic susceptibility and chemical shift artifacts were slightly more noticeable at 7 T. MR imaging at 3 and at 7T provides high spatial resolution and contrast images of the canine brain |
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RADIOGRAPHY AND COMPUTED TOMOGRAPHY IN THE DIAGNOSIS OF NONNEOPLASTIC EQUINE MANDIBULAR DISEASE |
• CT allowed identification of teeth that were clinically affected but appeared normal radiographically. Parameters such as tooth pulp involvement, lamina dura destruction, presence of bone fragments, lingual and buccal mandibular bone periosteal reaction, and cortical bone destruction were more conspicuous with CT. • Performing radiography and CT in horses with nonneoplastic mandibular disease provides a more complete evaluation than either technique alone. |
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THE APPEARANCE OF THE EQUINE METACARPOPHALANGEAL REGION ON HIGH-FIELD VS. STANDING LOW-FIELD MAGNETIC RESONANCE IMAGING |
• We found that larger anatomic structures were visible with sharp margins on both high- and low-field images, smaller structures were less distinct on low-field images and therefore interpretation of smaller structures on low-field images must be done with care |
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THE EFFECT OF THE SAMPLE SIZE AND LOCATION ON CONTRAST ULTRASOUND MEASUREMENT OF PERFUSION PARAMETERS |
• Three separate sets of ROIs were placed in the renal cortex, varying in location, size or depth. There was a significant inverse association between increased depth or increased size of the ROI and peak intensity (Po0.05). • There was no statistically significant difference in the peak intensity between the ROIs placed in a row in the near field cortex. There was no significant difference in the ROIs with regard to arrival time, time to peak intensity and wash-in rate. • When comparing two different ROIs in a patient with focal lesions, such as suspected neoplasia or infarction, the ROIs should always be placed at same depth and be as similar in size as possible |
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THE VETMOUSETRAP: A DEVICE FOR COMPUTED TOMOGRAPHIC IMAGING OF THE THORAX OF AWAKE CATS |
• A statistically significant difference was found for SNR (P1⁄40.001) and CNR (P 1⁄4 0.001) between all protocols. The higher pitch protocols had significantly lower noise and higher SNR and CNR, lower motion artifact but greater helical artifacts. A protocol using 80 kV, 130 mA, 0.5 s, and 0.562 pitch with 1.25 mm slice thickness, and 0.625 mm slice reconstruction interval is recommended. • The VetMousetrapt appears to provide the opportunity for diagnostic CT imaging of the thorax of awake cats. |
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ULTRASONOGRAPHIC FINDINGS IN HORSES WITH FOOT PAIN BUT WITHOUT RADIOGRAPHICALLY DETECTABLE OSSEOUS ABNORMALITIES |
• Thirty of the 39 horses had lesions affecting the deep digital flexor tendon (DDFT), 27 had abnormalities in the distal interphalangeal joint of which six had a visible abnormality in the collateral ligament. • Ultrasonographic abnormalities were seen in the podotrochlear bursa in 22 horses and in the ligaments of the navicular bone in two horses. Abnormalities of the navicular bone flexor surface were detected in eight horses. In three of the 39 horses, only the DDFT was affected. • The other 36 horses had ultrasonographic abnormalities in more than one anatomical structure. Based on our results, ultrasonographic examination provides useful diagnostic information in horses without radiographic changes |
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USE OF TRANSSPLENIC INJECTION OF AGITATED SALINE AND HEPARINIZED BLOOD FOR THE ULTRASONOGRAPHIC DIAGNOSIS OF MACROSCOPIC PORTOSYSTEMIC SHUNTS IN DOGS |
• Agitated saline mixed with 1 ml of heparinized autologous blood was injected into the spleen of 34 sedated dogs under sonographic guidance. The transducer was then sequentially repositioned to visualize the portal vein, the caudal vena cava, and the right atrium through different acoustic windows. • It was possible to differentiate between intrahepatic and extrahepatic shunts depending on the entry point of the microbubbles into the caudal vena cava. Portoazygos shunts and portocaval shunts could be differentiated based on the presence of microbubbles in the caudal vena cava and/or the right atrium. • The technique was also used post- operatively to assess the efficacy of shunt closure. All abnormal vessels were confirmed by exploratory laparotomy or with ultrasonographic identification of the shunting vessel. |
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CORRELATING MAGNETIC RESONANCE FINDINGS WITH NEUROPATHOLOGY AND CLINICAL SIGNS IN DOGS AND CATS |
• The histologic characteristics that are the basis for diagnosis of central nervous system conditions cannot be visualized directly using magnetic resonance (MR) methods, but clinical diagnosis may be based on the frequency and pattern of MR imaging signs, which represent predominantly the gross morphologic features of lesions. • Additional quantitative MR measures of myelination, cell swelling, gliosis, and neuronal loss may also be used for more specific characterization of lesions. These measures include magnetization transfer ratio, apparent diffusion coefficient, and the concentrations or ratios of metabolites identified by spectroscopy. |
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IMAGING DOGS WITH SUSPECTED DISC HERNIATION: PROS AND CONS OF MYELOGRAPHY, COMPUTED TOMOGRAPHY, AND MAGNETIC RESONANCE |
• Where high-field MR imaging is available, it is considered the optimal modality for any myelopathy in dogs, including those with disc disease. CT myelography may be the next best option, particularly in nonchondrodystrophoid dogs. • In chondrodystrophoid dogs, in which extrusion of mineralized disc material is common, plain CT will enable diagnosis in most cases. Myelography is still considered adequate for diagnosis of disc herniation when MR and CT are unavailable. |
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IMAGING THE CRANIAL NERVES |
• An understanding of the normal course of the cranial nerves (CN) is essential when interpreting images of patients with cranial neuropathies. CN foramina are depicted best using computed X-ray tomography, but the nerves are depicted best using magnetic resonance imaging. • The function and anatomy of the CN in the dog are reviewed and selected examples of lesions affecting the CN are illustrated. |
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MAGNETIC RESONANCE IMAGING FEATURES OF CANINE INTRACRANIAL NEOPLASIA |
• The MR imaging features of common canine central nervous system (CNS), adenohypophyseal, and metastatic intracranial neoplasms are reviewed. • Characterization of neoplasms by histologic type and biological grade is based on the 2007 World Health Organization classification system for CNS tumors in humans |
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MAGNETIC RESONANCE IMAGING OF INTRACRANIAL MALFORMATIONS IN DOGS AND CAT |
• Malformations of the brain include hydrocephalus, hydranencephaly/porencephaly, holoprosencephaly, corpus callosum agenesis/dysgen- esis, lissencephaly, polymicrogyria, meningoencephalocele, intracranial cysts, cerebellar malformations, and hamartomas. These conditions are defined and reviewed with an emphasis on their features in magnetic resonance images. |
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MAGNETIC RESONANCE IMAGING OF NORMAL AND ABNORMAL BRAIN PERFUSION |
• Magnetic resonance (MR) imaging is one of several imaging methods used to evaluate brain perfusion and stroke. Using a multisequence approach comprised of conventional spin echo, inversion recovery, and heme-sensitive gradient echo pulse sequences, MR angiography, and diffusion and perfusion sensitive techniques, MR imaging is capable of identifying vascular lesions, measuring abnormal blood flow, and depicting the metabolic and structural consequences of ischemia. • MR imaging objectives and strategies for the diagnosis of acute ischemic stroke in humans and animals, terminology, pathophysiology, and normal vascular anatomy are reviewed |
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OPTIMAL MAGNETIC RESONANCE IMAGING OF THE BRAIN |
• Quality magnetic resonance (MR) imaging is complex and requires optimization of many technical factors. The most important factors are: magnet field and gradient strengths, coil selection, receiver bandwidth, field of view and image matrix size, number of excitations, slice thickness, image weighting and contrast, imaging planes and the direction of the phase, and frequency gradients. • The ability to augment a standard MR study with additional sequences, and the need to ensure the completed study is comprehensive and robust must be balanced against the time the patient spends under anesthesia in the magnet |
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OPTIMAL MAGNETIC RESONANCE IMAGING OF THE SPINE |
• Magnetic resonance (MR) imaging is generally considered to be the best imaging modality for the spine because of its excellent tissue contrast and multiplanar imaging capability; however, good technique is vital in order to avoid nondiagnostic or even misleading images. • The possibility of imaging in multiple planes and using many different pulse sequences means that judgment is required in order to gain maximum diagnostic information within a reasonable scanning time. |
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PROS AND CONS OF LOW-FIELD MAGNETIC RESONANCE IMAGING IN VETERINARY PRACTICE |
• Low-field (LF) (0.2–0.4 T) magnetic resonance (MR) imaging predominates in veterinary practice. • Advantages of LF MR include reduced costs, better patient access, and greater safety. High quality examinations can be achieved using appropriate protocols and investing more scanning time than with high-field (HF) systems. • The main disadvantage of LF MR is the reduced signal to noise ratio compared with HF systems. LF MR protocols for small animal brain and spine imaging are described. |
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GROWTH OF CLINICAL VETERINARY MAGNETIC RESONANCE IMAGING |
• Veterinary institutions started installing magnetic resonance (MR) scanners in the 1990s. Since then, clinical use of MR has grown in parallel with the development of specialized veterinary medicine, particularly in the field of neurology, which has been transformed by MR. • Similarly, the introduction of MR for horses has revolutionized diagnosis of foot lameness. As MR imaging technology develops and MR scanners become more readily available to the veterinary profession, there is a growing need for more teaching and research about use of this remarkable modality |
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VALUE OF FAT SUPPRESSION IN GADOLINIUM-ENHANCED MAGNETIC RESONANCE NEUROIMAGING |
• T1-weighted, gadolinium-enhanced magnetic resonance imaging is frequently used to investigate neurologic disease in small animals; however, the abundance of hyperintense adipose tissue adjacent to neural structures, particularly the cranial nerves and spinal cord, can decrease the conspicuity of contrast-enhanced tissues on T1- weighted images. • For this reason, chemical fat saturation techniques are used to suppress the signal of adipose tissues, enabling improved depiction of gadolinium-enhanced structures and detection of lesions affecting the nervous system |
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COMPUTED TOMOGRAPHIC APPEARANCE OF PRIMARY LUNG TUMORS IN DOGS |
• Nineteen dogs with computed tomographic (CT) images of the thorax and a histological diagnosis of primary lung tumor (17 primary carcinomas and two primary sarcomas) were evaluated retrospectively to characterize the CT findings. All primary lung tumors were bronchocentric in origin with internal air bronchograms. The bronchi were typically narrowed, displaced, and often obstructed by the tumor. • Eighteen of 19 (95%) of the tumors were solitary and there was one pneumonic/alveolar form. Most solitary tumors were well circumscribed (17/18), located in the central to periphery of the lung (14/18), and in a cranial or caudal lobe (16/19). Most primary lung tumors (11/17) had mild to moderate heterogeneous contrast enhancement. Five of 19 dogs (26%) had evidence of pulmonary metastasis. Internal mineralization (3/19) and tracheobronchial lymphadenopathy (4/19) were also identified. • On CT examination, solitary, well circumscribed, bronchocentric masses with internal air bronchograms are consistent with a primary pulmonary tumor in dogs. |
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DETERMINATION OF T1 RELAXATION TIME OF NORMAL EQUINE TENDONS USING MAGIC ANGLE MAGNETIC RESONANCE IMAGING |
• MR imaging of the metacarpi was performed with the limbs positioned at 551 (the magic angle) relative to the main magnetic field. Transverse spin-echo proton density and inversion recovery images were acquired. • T1 relaxation time was calculated based on ratios of signal intensity determined from the different pulse sequences. T1 relaxation times for SDFT, DDFT, and SL were 288 ( 17), 244 ( 14), and 349 ( 16) ms, respectively. The difference in T1 values between SDFT, DDFT, and SL was statistically significant. T1 values of equine tendons can be determined with magic angle imaging on a clinical MR system using o10 min total scan time. • The knowledge of the normal range of T1 values may be useful to identify horses with chronic tendinopathy, where based on the human literature, an increased T1 value may be expected. • The magic angle effect has been previously reported as an artifact in the distal part of the deep digital flexor ten- don (DDFT) and in the collateral ligaments of the distal interphalangeal joint of the horse. This may occur in conventional MR imaging of the equine foot and needs to be recognized to avoid false diagnosis of lesions. • Structures appear hyperintense due to the occurrence of the magic angle effect. |
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ESTIMATED OPERATOR EXPOSURE FOR HAND HOLDING PORTABLE X-RAY UNITS DURING IMAGING OF THE EQUINE DISTAL EXTREMITY |
• The average hand and collar dose was 0.471 and 0.327 mR/ exposure, respectively. The lead apron and glove attenuated the primary beam 96.9 and 99.2%, respectively. This reduced average hand and collar exposures to 0.0038 and 0.0101 mR/exposure, respectively. • Theoretical occupational limits are reached for the collar (whole body) before the hand (extremity). |
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EVALUATION OF MAGNETIC RESONANCE SAFETY OF VETERINARY RADIOFREQUENCY IDENTIFICATION DEVICES AT 1T |
• These devices are the most commonly encountered metallic implants in dogs and cats undergoing MR imaging. Three commercial veterinary microchips were evaluated for safety in the MR environment at 1T. Parameters tested were translational force, torque, heating, artifact production, and function. • Translation and torque were larger than that expected from normal activity under normal gravity. No significant heating was observed. Signal void artifacts may affect diagnosis if they are too close to the area of clinical importance. Microchip function was unaffected by routine clinical MR imaging. • Capsule formation around devices is a major factor in counteracting translation and torque. Our findings support that is acceptable for patients to undergo MR imaging with this 1 T system following an interval of 3 months post-implantation to allow capsule growth. Because of the complex interactions involved, these observations may not be translatable to MR scanners of different field strength and/or manufacturer. |
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IMAGING DIAGNOSIS—CT MYELOGRAPHY IN A DOG WITH INTRAMEDULLARY INTERVERTEBRAL DISC HERNIATION |
• Computed tomography (CT) of the T9-L5 vertebrae was normal. Myelography disclosed attenuation of the subarachnoid space from T11 to L1, consistent with spinal cord swelling. • CT following the myelogram disclosed a focal area of intramedullary iodinated contrast medium at T13-L1. At surgery, intervertebral disc material was removed from the spinal cord |
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IMAGING DIAGNOSIS—MAGNETIC RESONANCE IMAGING FEATURES OF METASTATIC CEREBRAL LYMPHOMA IN A DOG |
• In magnetic resonance (MR) images there was a heterogeneous, contrast-enhancing, extraaxial mass in the right parietal and piriform lobes at the level of the optic chiasm. Our MR imaging findings are consistent with reports in humans in that lymphoma masses have indistinct borders that are iso- to hyperintense relative to adjacent gray matter on T2-weighted images. • Our report varies from findings in humans in that the mass was extraaxial, whereas masses reported in humans are intraaxial. Contrast enhancement can be heterogeneous, as in our report, or homogeneous. |
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IMAGING DIAGNOSIS—MAGNETIC RESONANCE IMAGING FINDINGS OF PRIMARY CEREBRAL HEMANGIOMA |
• Intracranial hemangioma is a rare intraaxial hemorrhagic neoplasm with imaging characteristics similar to other intracranial hemorrhagic lesions. We describe two canine cerebral hemangiomas that appeared as poorly circumscribed intraaxial compressive lesions that were predominantly hypointense on T2 sequences and heterogeneously contrast enhancing. • Both lesions had perilesional edema and were hypointense on T2 -gradient recalled echo sequences, consistent with hemorrhage. In one tumor a short partial peripheral rim was present, which was suggestive of hemosiderin deposition |
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INTRAOPERATIVE CONTRAST-ENHANCED ULTRASONOGRAPHY OF NORMAL CANINE JEJUNUM |
• Three different doses of ultrasound contrast medium (Definity) were injected through a peripheral venous catheter. Time-intensity curves were used to calculate baseline, time to initial rise, inflow slope, time-to- peak, peak intensity (PI), and outflow slope for each administered dose. • PI was directly proportional to dose. Outflow slope was similar for all patients, independent of dose. The most favorable images were acquired with a dose of 0.030 ml/kg given as a rapid intravenous manual bolus. • The technique and normal jejunal perfusion pattern described herein may provide useful data for evaluation of intestinal vascular, inflammatory, and neoplastic disease in the dog |
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MAGNETIC RESONANCE IMAGING APPARENT DIFFUSION COEFFICIENTS FOR HISTOLOGICALLY CONFIRMED INTRACRANIAL LESIONS IN DOGS |
• Disease categories included: meningiomas, glial cell tumors, choroid plexus tumors, pituitary tumors, inflammatory brain diseases, acute nonhemorrhagic infarcts, chronic nonhemorrhagic infarcts, and hemorrhagic infarcts. • A wide range of ADC value distributions were identified within the disease groups, and there were overlapping ADC values between most groups. Low ADC values indicating restricted diffusion of water were identified in acute nonhemorrhagic infarcts as expected, but were also seen in meningiomas, glial cell tumors, and granulomatous meningoencephalitis. • Based on this preliminary data it is unlikely that singular quantitative ADC values can be used to determine the histological type of canine intracranial disease. |
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MAGNETIC RESONANCE IMAGING FEATURES OF DISCOSPONDYLITIS IN DOGS |
• The involved endplates and adjacent marrow were T1-hypointense with hyperintensity in short tau inversion recovery (STIR) images in all dogs, and all dogs also had contrast enhancement of endplates and paravertebral tissues. • The intervertebral disks were hyperintense in T2W and STIR images and characterized by contrast enhancement in 15 sites (88.2%). Endplate erosion was present in 15 sites (88.2%) and was associated with T2-hypointense bone marrow adjacent to it. In two sites (11.8%) endplate erosion was not MR images or radiographically. • The vertebral bone marrow in these sites was T2-hyperintense. Epidural extension was conspicuous in postcontrast images at 15 sites (88.2%). Spinal cord compression was present at 15 sites (88.2%), and all affected dogs had neurologic signs. Subluxation was present in two sites (11.8%) |
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MAGNETIC RESONANCE IMAGING FEATURES OF INTRACRANIAL ASTROCYTOMAS AND OLIGODENDROGLIOMAS IN DOGS |
• Astrocytomas and oligodendrogliomas represent one third of histologically confirmed canine brain tumors. All oligodendrogliomas and 12 astrocytomas were located in the cerebrum or thalamus, with the remainder of astrocytomas in the cerebellum or caudal brainstem. Most (27/30) tumors were associated with both gray and white matter. The signal characteristics of both tumor types were hypointense on T1-weighted images (12 each) and hyperintense on T2-weighted images (11/14 astrocytomas, 12/16 oligodendrogliomas). • For astrocytomas and oligodendrogliomas, respectively, common findings were contrast enhancement (10/13, 11/15), ring-like contrast enhancement (6/10, 9/11), cystic regions within the mass (7/14, 12/16), and hemorrhage (4/14, 6/16). Oligodendrogliomas were significantly more likely to contact the brain surface (meninges) than astrocytomas (14/ 16, 7/14, respectively, P 1⁄4 0.046). Contact with the lateral ventricle was the most common finding, occurring in 13/14 astrocytomas and 14/16 oligodendrogliomas. |
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MEASUREMENT OF BODY COMPOSITION IN CATS USING COMPUTED TOMOGRAPHY AND DUAL ENERGY X-RAY ABSORPTIOMETRY |
• By examining the frequency distribution of voxels by Hounsfield unit (HU) value, it is possible to calculate a fat index (Fat%) that is in close agreement with the fat percentages obtained from DEXA scans. • Fat% values obtained by the best of the methods had a mean difference of 0.96% (95% confidence interval 0.33–1.59%) from the DEXA results. |
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PULMONARY ANGIOGRAPHY USING 16 SLICE MULTIDETECTOR COMPUTED TOMOGRAPHY IN NORMAL DOGS |
• Arterial enhancement of transverse and reformatted images was classified subjectively as excellent, good, or poor, and assessed objectively by measuring Hounsfield units at the right main pulmonary artery. Angiographic studies were evaluated by two radiologists to determine the number of subsegmental arterial branches visualized. • The median number of subsegmental arterial branches identified was five (range: 2–7). Based on the time attenuation curve obtained by the bolus-tracking program, there was consistent enhancement of the right main pulmonary artery beginning at 6 s and peaking at 8 s in 4/5 dogs. • The contrast medium dose of 400 mg I/kg produced good to excellent vascular enhancement in the same 4/5 dogs. |
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REIRRADIATION OF RECURRENT CANINE NASAL TUMORS |
• The qualitative response assessment was better for the first course compared with the second (P 1⁄4 0.018). • Severity and timing of skin, mucous membrane, and ocular effects were similar for early side effects between the two courses (P40.05 for all comparisons). All dogs experienced some late side effects, with two out of nine being classified as severe. • Reirradiation of canine nasal tumors resulted in a second clinical remission in eight of nine dogs, although the second response was less complete. |
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THE EFFECT OF SEQUENCE SELECTION AND FIELD STRENGTH ON DETECTION OF OSTEOCHONDRAL DEFECTS IN THE METACARPOPHALANGEAL JOINT |
• The following sequences were performed using all three systems: proton density (PD) turbo spin echo, T2 gradient echo (GRE), T2-weighted fast spin echo, and short tau inversion recovery. In addition, 3D T1 GRE sagittal standard and motion insensitive sequences were obtained using the low-field system. • PD fat saturated and 3D T1-weighted spoiled GRE images with and without fat suppression were acquired with the high-field systems. Lesions were measured and assigned a confidence score. The images obtained using high-field systems (1.0 and 1.5 T) more accurately represented the osteochondral defects when compared with low-field system (0.27 T) images. • The largest difference was observed when evaluating articular cartilage defects, which were not identified on the low-field images. |
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ABDOMINAL ULTRASONOGRAPHIC FINDINGS IN DOGS NATURALLY INFECTED WITH BABESIOSIS |
• The most common finding in all dogs was splenomegaly with a diffuse heterogenic parenchyma and generally reduced echogenicity. • Diffuse hypoechoic hepatomegaly and bilaterally increased cortical echogenicity of the renal parenchyma were found more frequently in severe uncomplicated and complicated babesiosis groups. |
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COMPARATIVE POPLITEAL AND MESENTERIC COMPUTED TOMOGRAPHY LYMPHANGIOGRAPHY OF THE CANINE THORACIC DUCT |
• Popliteal administration produced a successful thoracic duct lymphangiogram in eight of 11 dogs (73%) after two attempts, while mesenteric administration was successful in eight of 10 dogs (80%) after a single attempt. • Popliteal lymphography required 46% of the time and was associated with less patient discomfort than mesenteric lymphangiography. The number of thoracic duct branches seen was not significantly different for either administration technique (P 1⁄4 0.256) or CT acquisition mode (P 1⁄4 0.417). • However, the cross-sectional area and mean HU of the largest thoracic duct branch were greater with mesenteric administration |
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COMPARISON OF RADIOGRAPHY AND ULTRASONOGRAPHY FOR DIAGNOSING SMALL-INTESTINAL MECHANICAL OBSTRUCTION IN VOMITING DOGS |
• Radiography produced a definitive result (obstructed or not obstructed) in 58/82 (70%) of dogs; ultrasonography produced a definitive result in 80/82 (97%) of dogs • In conclusion, both abdominal radiography and abdominal ultrasonography are accurate for diagnosing small-intestinal obstruction in vomiting dogs and either may be used depending on availability and examiner choice. • Abdominal ultrasonography had greater accuracy, fewer equivocal results and provided greater diagnostic confidence compared with radiography |
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COMPARISON OF THE IMAGE QUALITY OF A HIGH-RESOLUTION SCREEN–FILM SYSTEM AND A DIGITAL FLAT PANEL DETECTOR SYSTEM IN AVIAN RADIOGRAPHY |
• In conclusion the digital technique is equal or superior to the conventional screen–film high- resolution system for pet birds of a medium size. With some limitations, a dose reduction is possible with the digital system. |
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CONTRAST-ENHANCED PORTAL MAGNETIC RESONANCE ANGIOGRAPHY IN DOGS WITH SUSPECTED CONGENITAL PORTAL VASCULAR ANOMALIES |
• Portal vascular anomalies were identified in 16 of the 17 dogs. Eleven had a single intrahepatic portocaval shunt (two central divisional, three right divisional, and six left divisional), one dog had a double intrahepatic portocaval shunt, one dog had a hepatic arteriovenous malformation, one dog had a complex intrahepatic portocaval shunt. Two dogs had an extrahepatic portosystemic shunt and no shunt was identified in one dog • CE-MRA is an efficient imaging technique for the diagnosis of portal vascular anomalies in dog |
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IDENTIFICATION AND PREVALENCE OF ERRORS AFFECTING THE QUALITY OF RADIOGRAPHS SUBMITTED TO AUSTRALIAN THOROUGHBRED YEARLING SALE REPOSITORIES |
• Positioning errors were the most common reason for radiographs to be considered nondiagnostic (2432/81,297; 3%), with the flexed lateromedial (LM) metacarpophalangeal joint, LM metatarsophalangeal joint, and the dorsomedial palmarolateral (DMPaLO) carpal views being the most frequently involved. • Overexposure (14,357/81,297; 17.7%) was the most common reason for radiographs being categorized as less than ideal with the LM stifle view the most represented. |
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IMAGING DIAGNOSIS—INTRACRANIAL CRYPTOCOCCAL MASS IN A CAT |
• A diagnosis of a cryptococcal mass was made based on imaging and additional diagnostics. Complete resolution of the mass was demonstrated by follow-up imaging. This report serves as a reminder that masses associated with cryptococcal infection should be included on the differential list for cats with intracranial masses. • The latex cryptococcal antigen test (LCAT) for C. neoformans was positive at 1:1118. |
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IMAGING DIAGNOSIS—MAGNETIC RESONANCE IMAGING PULSATILITY ARTIFACT IN THE CANINE CERVICAL SPINE |
• Linear T2- hyperintensities in the spinal cord at the cranial aspect of C3 and C4 in transverse T2-weighted images in large breed dogs that are not accompanied by ghosting. The artifact is more conspicuous in pre- and postcontrast transverse T1-weighted images and is accompanied by ghosting in that sequence, typical of a pulsatility artifact. • A flow-related artifact was confirmed as the cause for this appearance by noting its absence after either exchange of phase and frequency encoding direction or by flow compensation. |
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IMAGING DIAGNOSIS—SYNOVIAL MYXOMA OF LUMBAR VERTEBRAE ARTICULAR PROCESS JOINT |
• Magnetic resonance (MR) imaging and histopathology were used to diagnose an articular process synovial myxoma in a dog. On MR images, the tumor was characterized by distortion of the left L1–L2 articular process, widening of the articular process joint, and the presence of a mass contiguous with the synovium of the articular process that displaced the spinal cord. • The tumor was T2-hyperintense, T1-hypointense, relative to muscle, and had mild contrast enhancement. |
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MAGNETIC RESONANCE ANATOMY OF THE CARPUS OF THE HORSE DESCRIBED FROM IMAGES ACQUIRED FROM LOW-FIELD AND HIGH-FIELD MAGNETS |
• Normal MRI anatomy in transverse, sagittal, and dorsal plane images was determined by comparison with anatomical specimens and standard texts. Subchondral bone and cortical bone thickness measurements were obtained from standardised sites. • There was variable subchondral bone thickness in the radius and carpal bones; subchondral bone thickness was consistently larger at dorsal compared with palmar sites in the proximal row of carpal bones. The endosteal surface of the subchondral bone was smooth. The shape of the ulnar carpal bone was variable and one or more small osseous fragments were identified palmar to the bone in 5/30 limbs. There was no evidence to suggest that these were pathological fractures or avulsions of the lateral palmar intercarpal ligament. • The amount of muscle tissue in the superficial and deep digital flexor tendons in the proximal aspect of the carpus varied, but none was present at the level of the middle carpal joint and distally. Several structures could be evaluated that cannot be imaged using radiography, ultrasonography, or arthroscopy, including the transverse intercarpal ligaments, the radiocarpal ligament, the short palmar carpal ligaments, and the carpometacarpal ligaments. Anatomical variations not previously described were identified, including the layers of the medial aspect of the carpal fascia. |
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RADIOGRAPHIC CHARACTERIZATION OF THE OS PENIS IN THE CAT |
• An os penis was detected in 19/50 (38%) cats with CR and in eight of 50 (16%) cats with analog radiography; this difference was statistically significant. With CR, the median age of cats with a visible os penis was significantly higher than in cats where the os penis was not seen. |
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RADIOGRAPHIC EVALUATION OF FELINE APPENDICULAR DEGENERATIVE JOINT DISEASE VS. MACROSCOPIC APPEARANCE OF ARTICULAR CARTILAGE |
• The joints most likely to have cartilage damage without radiographic evidence of DJD are the stifle (71% of radiographically normal joints) followed by the coxofemoral joint (57%), elbow (57%), and tarsal joint (46%). • Our data support radiographic findings not relating well to cartilage degeneration, and that other modalities should be evaluated to aid in making a diagnosis of feline DJD. |
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SAFETY AND CORRELATION OF TEST RESULTS OF COMBINED ULTRASOUND-GUIDED FINE-NEEDLE ASPIRATION AND NEEDLE CORE BIOPSY OF THE CANINE SPLEEN |
• Diagnoses were categorized as neoplastic, benign, inflammatory, normal, or nondiagnostic. The level of agreement between sampling methods was categorized as complete, partial, disagreement, or not available. Test correlation was performed in 40 dogs. Nondiagnostic results occurred in 5/40 NCB (12.5%) and no FNA samples. • Neoplasia was diagnosed in 17/40 dogs (42.5%), benign changes in 20/40 dogs (50%), inflammatory disorders in 0/40 dogs, and normal 2/40 dogs (5%) • Percutaneous FNA and NCB can be performed safely in dogs with sonographic splenic changes. Results suggest that adding NCB to FNA provides complementary information in dogs with suspected splenic neoplasia. |
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STATIC AND DYNAMIC 18FDG-PET IN NORMAL HISPANIOLAN AMAZON PARROTS (AMAZONA VENTRALIS) |
• Reflux of radioactive material from the cloaca into the colon occurred in all birds to varying degrees and occurred before 60 min. To evaluate the intestinal tract of clinical avian patients, dynamic scans must be performed starting immediately after injection so that increased radioactivity due to metabolism or hypermetabolic lesions such as cancer can be differentiated from increased radioactivity due to reflux of fluid from the cloaca |
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THORACIC COMPUTED TOMOGRAPHY FINDINGS IN DOGS EXPERIMENTALLY INFECTED WITH ANGIOSTRONGYLUS VASORUM |
• A multicentric bronchoalveolar pattern more pronounced at the lung periphery was present radiographically. On CT, the predominant abnormality underlying this alveolar pattern was multiple large nodules merging to areas of consolidation, and containing air bronchograms of varying extent. • These nodular changes corresponded to histopathologic granulomata, consisting mainly of macrophages, multinucleated giant cells, and lymphocytes that had accumulated around larvae and eggs • Regional lymph nodes were enlarged after infection, and smaller after treatment. On postcontrast CT, several suspicious intraluminal filling defects suggestive of thrombosis were found; however, the tortuosity of some pulmonary arteries seen radiographically was not present in CT images. After treatment, the consolidations and large nodules had almost completely disappeared. A remaining radiographic interstitial pattern was characterized on CT as ground-glass opacifications, subpleural interstitial thickening, subpleural lines, and interface signs. |
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ULTRASONOGRAPHIC CHARACTERIZATION OF FELINE ILEOCECOCOLIC ABNORMALITIES |
• The clinical signs of 29 cats with ultrasonographic abnormalities at the ileocecocolic junction were reviewed. Twenty-eight cats had gastrointestinal signs, with acute vomiting and diarrhea being most prevalent. Eighteen of 29 cats had enlarged cecal lymph nodes. • Focal hyperechoic mesenteric fat was noted in 18 of 29 cats, and mild focal fluid accumulation was seen in seven of 29 cats. Six cats had a round cecum, and eight cats had cecal content. The cecal wall was thickened in 19 cats, and the ileal wall was mildly thickened in six cats. Three cats had changes involving the ascending colon adjacent to the ileocecocolic junction. Fourteen cats had no ultrasonographic evidence of changes in the remainder of the gastrointestinal tract, and 13 of these 14 cats were symptomatic for gastrointestinal disease. • Fine-needle aspirates and biopsies of the ileocecocolic area had a low diagnostic yield. |
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ULTRASONOGRAPHY OF INTESTINAL MAST CELL TUMORS IN THE CAT |
• The mean age was 13.4 2.5 years. There were 16 focal intestinal tumors and one diffuse submucosal infiltrate. The most common pattern was focal, hypoechoic wall thickening that was noncircumferential and eccentric (9/16 tumors) or circumferential, asymmetric, and eccentric (5/16 tumors). Nine of the cats had lesions in the jejunum or duodenum, four were at the ileocecocolic junction, and one cat had a colonic mass. • Nine cats had enlarged abdominal lymph nodes, and seven were due to metastatic disease. Metastatic disease was not routinely detected by ultrasound in the liver (1/4 cats) or the spleen (0/3 cats). Concurrent small cell (T cell) lymphoma was present in four of 14 cats (29%) |
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ULTRASOUND-GUIDED MESENTERIC LYMPH NODE IOHEXOL INJECTION FOR THORACIC DUCT COMPUTED TOMOGRAPHIC LYMPHOGRAPHY IN CATS |
• Computed tomographic (CT) lymphography was performed in cats using percutaneous ultrasound-guided injection of contrast medium into a mesenteric lymph node. The thoracic duct and its branches were clearly delineated in CT images of seven cats studied. The thoracic duct was characterized by anatomic variation and appeared as single or multiple branches. • The thoracic duct and the cisterna chyli were identified along the ventral or left ventral aspect of the vertebrae from the level of the cranial lumbar to the caudal cervical vertebrae. The thoracic duct was identified in the central caudal mediastinum, deviated to the left in the cranial mediastinum, and finally moved toward the venous system. Small volumes of extranodal contrast medium leakage were identified in all cats. After injection, the mesenteric lymph nodes were cytologically normal. • Contrast medium injection was continued for 30–45 s . |
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CEPHALOMETRIC MEASUREMENTS AND DETERMINATION OF GENERAL SKULL TYPE OF CAVALIER KING CHARLES SPANIELS |
• The calculated parameters of the CKCS were different from all parameters of mesaticephalic dogs but were the same as parameters from brachycephalic dogs. However, the CKCS had a wider braincase in relation to length than in other brachycephalic breeds. • Studies of the etiology of the chiari-like malformation in the CKCS should therefore focus on brachycephalic control groups. |
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COMPARISON OF SONOGRAPHIC FEATURES OF BENIGN AND NEOPLASTIC DEEP LYMPH NODES IN DOGS |
• Thirty-one deep lymph nodes (16 mesenteric, 10 medial iliac, three hepatic, one sternal, and one cranial mediastinal) in 31 dogs were examined prospectively with B-mode and Color flow Doppler • Ten lymph nodes were benign (hyperplastic and/or inflammatory) and 21 were neoplastic. All were hypoechoic, except for one neoplastic lymph node. Maximal short-axis diameter (P 1⁄4 0.0006) and long-axis diameter (P 1⁄4 0.01), and SA/LA ratio (P 1⁄4 0.008) were increased significantly for neoplastic (2.8, 5.5 cm, and 0.50, respectively) vs. benign (1.2, 3.8 cm, and 0.34, respectively) lymph nodes. The prevalence of other features was similar between groups. Doppler evaluation was possible in 77% of lymph nodes, but there was no significant difference between groups • The benign LN were not confirmed by histopath |
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COMPUTED TOMOGRAPHIC IMAGING OF DOGS WITH PRIMARY LARYNGEAL OR TRACHEAL AIRWAY OBSTRUCTION |
• The CT and 3D internal rendering accurately indicated the presence and cause of upper airway obstruction in all dogs. • CT findings indicative of laryngeal paralysis included failure to abduct the arytenoid cartilages, narrowed rima glottis, and air-filled laryngeal ventricles. Laryngeal collapse findings depended on the grade of collapse and included everted laryngeal saccules, collapse of the cuneiform processes and corniculate processes, and narrowed rima glottis. • Trachea abnormalities included hypoplasia, stenosis, or collapse syndrome. The CT findings in tracheal hypoplasia consisted of a severely narrowed lumen throughout the entire length. Tracheal stenosis was represented by a circumferential decrease in tracheal lumen size limited to one region. Tracheal collapse syndrome was diagnosed by severe asymmetric narrowing. |
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COMPUTED TOMOGRAPHY OF THE PHARYNX IN A CLOSED VS. OPEN MOUTH POSITION |
• The ability of radiologists to classify anatomic regions as normal or abnormal vs. unsure also varied between mouth positions, and there was greater uncertainty when the mouth was closed. • In addition, estimated volume of the air-filled nasopharynx differed significantly as a function of mouth position and was greater when the mouth was open (mean1⁄41.187cm3, SE1⁄40.177) vs. closed (mean1⁄40.584cm3, SE1⁄40.116). Computed tomographic evaluation of the pharynx can be improved with the mouth open. |
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CONTRAST ENHANCED SONOGRAPHIC ASSESSMENT OF FEEDING VESSELS AS A DISCRIMINATOR BETWEEN MALIGNANT VS. BENIGN FOCAL SPLENIC LESIONS |
• A rapid influx of contrast agent, resulting in an increased relative echogenicity of the lesion, followed by a rapid clearance of contrast agent was referred to as early washin/early washout. There were 6/12 benign, and 3/5 malignant lesions characterized by early washin/early washout. • none of the benign and all malignant lesions were characterized by tortuous and persistently visible feeding vessels. This suggests that interpretation of splenic lesions cannot be performed accurately on the basis of echogenicity or persistent hypoperfusion, but that assessment of vascular tortuosity may be helpful in discriminating between a malignant vs. benign focal splenic lesion. |
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FRACTURES OF THE DISTAL PHALANX AND ASSOCIATED SOFT TISSUE AND OSSEOUS ABNORMALITIES IN 22 HORSES WITH OSSIFIED SCLEROTIC UNGUAL CARTILAGES DIAGNOSED WITH MAGNETIC RESONANCE IMAGING |
• All horses had a forelimb fracture. Eleven involved a left forelimb (seven medial; four lateral), and 12 involved a right forelimb (five medial; seven lateral). All fractures were nonarticular, simple in configuration, and nondisplaced. The fractures were oriented in an axial proximal to abaxial distal and palmar to dorsal direction, and extended from the base of the ossified ungual cartilage into the distal phalanx. The fracture involved the fossa of the collateral ligament on the distal phalanx in 17 of 23 limbs. • The palmar process and ossified ungual cartilage was abnormally mineralized in all horses. Ligaments and soft tissues adjacent to the ossified ungual cartilages were affected in all horses. The routine site of fracture in this study at the base of the ossified ungual cartilage extending into the distal phalanx suggests a biomechanical cause or focal stress point from cycling. |
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HEPATIC AND PANCREATICOBILIARY MRI AND MR CHOLANGIOPANCREATOGRAPHY WITH AND WITHOUT SECRETIN STIMULATION IN NORMAL CATS |
• Multiple MR sequences were evaluated, including fast Spoiled Gradient Recalled in- and out-of-phase, Single Shot Fast Spin Echo (SSFSE), T2 Fast Spin Echo, MR cholangiopancreatography (pre- and postsecretin administration), and Fast Acquisition with Multiphase Efgre (FAME) (postsecretin and before and after gadolinium administration). The MR cholangiopancreatography protocol with secretin stimulation was feasible and yielded high-contrast maps of the biliary ductal anatomy but the pancreactic duct was seen inconsistently • The FAME series most consistently provided visualization of biliary and postsecretin pancreatic ductal anatomy, combined with very good depiction of the liver and pancreas. |
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IMAGING DIAGNOSIS—BILATERAL ORTHOTOPIC URETEROCELES IN A DOG |
• Bilateral orthotopic ureteroceles were diagnosed using a combination of sonography, computed tomography (CT), and radiography. With CT excretory urography, the ureteroceles appeared as two intraluminal cystic structures in the vesicoureteral region of the urinary bladder, which directly communicated with dilated ureters. • Unlike the other imaging modalities CT excretory urography provided a definitive diagnosis by confirming the communication between the hydroureters and the cystic dilations in the caudodorsal aspect of the urinary bladder |
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IMAGING DIAGNOSIS—PORTAL VEIN APLASIA AND INTERRUPTION OF THE CAUDAL VENA CAVA IN THREE DOGS |
• Three dogs with portal vascular anomalies were identified by means of CT angiography as having portal vein aplasia with portal insertion into the caudal vena cava, azygos continuation of the caudal vena cava, and interruption of the pre-hepatic caudal vena cava. |
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MAGNETIC RESONANCE IMAGING FINDINGS IN 15 ACROMEGALIC CATS |
• Enlargement of the pituitary gland with suprasellar extension was present in all cats. No characteristic signal patterns were identified on T1-weighted and T2-weighted sequences. • Contrast enhancement was nonuniform in all cats, as was suspected involvement of the adjacent hypothalamus. A mass effect on the cavernous sinus and third ventricle was present in 13 cats. • Transtentorial herniation was present in one cat |
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MAGNETIC RESONANCE IMAGING FINDINGS IN HORSES WITH SEPTIC ARTHRITIS |
• MR findings included diffuse hyperintensity within bone and extracapsular tissue on fat-suppressed images in 14/14 horses (100%), joint effusion, synovial proliferation, and capsular thickening in 13/14 horses (93%), bone sclerosis in 11/14 horses (79%), and evidence of cartilage and subchondral bone damage in 8/14 horses (57%). Intravenous gadolinium was administered to five of the 14 horses and fibrin deposition was noted in all horses. • Other findings after gadolinium administration included synovial enhancement in 4/5 (80%) horses, and bone enhancement in 1/5 (20%) horses. The MR findings of septic arthritis in horses were consistent with those reported in people |
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MAGNETIC RESONANCE IMAGING SUSCEPTIBILITY ARTIFACTS DUE TO METALLIC FOREIGN BODIES |
• Severity of artifacts was graded as 0 (no interference with area of interest), 1 (extension of artifact to area of interest without impairment of diagnostic quality), 2 (impairment of diagnostic quality but diagnosis still possible), or 3 (severe involvement of area of interest resulting in nondiagnostic study). • Susceptibility artifacts were present in 99/754 (13.1%) of MR imaging studies and were most common in examinations of the brachial plexus, thorax, and cervical spine. • Artifacts were caused by identification microchips, ballistic fragments, skin staples/suture material, hemoclips, an ameroid constrictor, and surgical hardware. Three studies were nondiagnostic due to the susceptibility artifact. Adverse effects were not documented. |
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POSITIVE CONTRAST MAGNETIC RESONANCE BURSOGRAPHY FOR ASSESSMENT OF THE NAVICULAR BURSA AND SURROUNDING SOFT TISSUES |
• Distension of the proximal recess of the normal navicular bursa, proximal to the collateral sesamoidean ligament was achieved with 2 ml. Separation of the collateral sesamoidian ligament from the deep digital flexor tendon (DDFT) was achieved with 4ml. • The separation of the navicular bone from the DDFT and distal sesamoidian impar ligament required 6 ml. Ad- hesions were more clearly defined in the bursa of the two pathologic cadaver limbs following distension. • MR bursography used on clinical patients allowed the determination of the presence or absence of adhesions. |
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PULMONARY ANGIOGRAPHY WITH 64-MULTIDETECTOR-ROW COMPUTED TOMOGRAPHY IN NORMAL DOGS |
• Morphologically, characteristic features included a focal narrowing in the right cranial pulmonary artery in all dogs, which should not be mistaken as stenosis. While the right cranial pulmonary artery divided into two equally sized branches that were tracked into the periphery of the lung lobe in all dogs, only a single left cranial (cranial portion) lobar artery was present. • Compared with 1.25 and 2.5 mm retro-reconstructions, 0.625 mm reconstructions allowed for detection of significantly (P 0.05) more pulmonary artery segments and sharper depiction of vessel margins. |
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RADIOGRAPHIC AND ULTRASONOGRAPHIC EVALUATION OF THE PATELLAR LIGAMENT FOLLOWING TIBIAL TUBEROSITY ADVANCEMENT |
• In comparison with T0, all radiographic and ultrasonographic measurements increased significantly, 6 weeks postoperatively (P 0.04), and did not change 16 weeks postoperatively compared with T1. The subjective score worsened significantly from T0 to T1 and T0 to T2 (Po0.0001), and improved significantly from T1 to T2 (P 1⁄4 0.02). • Larger cage size was associated with a more severe increase in radiographic proximal thickness to total length ratio and ultrasonographic middle transverse area at both follow-up examinations (P 0.02). Dogs in which arthrotomy was not performed appeared to have ultra- sonographically less changes. |
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REACTION TO INTRAARTERIAL IONIC IODINATED CONTRAST MEDIUM ADMINISTRATION IN ANESTHETIZED HORSES |
• Ninety-seven received an intraarterial injection of ionic, iodinated contrast medium for computed tomographic assessment of the distal limb. Nine (9.0%) horses developed a reaction attributable to the contrast medium administration. Of those, 4/97 (4.0%) developed a skin response (three with urticaria, one with facial edema) within 20 min. Five (5.0%) developed elevation of heart rate and/or blood pressure immediately upon administration of the contrast medium. |
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SENSITIVITY OF LOW-FIELD T2 IMAGES FOR DETECTING THE PRESENCE AND SEVERITY OF HISTOPATHOLOGIC MENISCAL LESIONS IN DOGS |
• Focal areas of increased signal intensity were detected in 11/12 symptomatic dogs and 3/3 control dogs. Lesions mimicking meniscal tears (pseudotears) were identified at junctions between meniscal margins and adjacent connective tissue in control dogs and dogs with naturally occurring disease. • Histopathologic lesions were present in all menisci of both symptomatic and control dogs, including the menisci from two affected dogs that appeared grossly normal but were removed and submitted based on MR imaging findings • Histopathologic lesions identified included hyaline cartilage metaplasia and changes in the amount of ground substance and cellularity. |
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SONOGRAPHIC CHARACTERISTICS OF INTRAABDOMINAL ABSCESSATION AND LYMPHADENOPATHY ATTRIBUTABLE TO RHODOCOCCUS EQUI INFECTIONS IN FOALS |
• Intraabdominal abscesses were usually present in the ventral abdomen adjacent to the ventral body wall, well-marginated, and contained a mixed or complex echo pattern. • Lymphadenitis appeared as singular or multiple clusters of lymph nodes of mixed echogenicity adjacent to any portion of the gastrointestinal tract or body wall |
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THORACIC COMPUTED TOMOGRAPHY IN FELINE PATIENTS WITHOUT USE OF CHEMICAL RESTRAINT |
• For CT imaging, cats were in a positioning device using a 16 multislice helical CT system. Fifty-four cats had CT imaging of which 50 had thoracic radiography. The most common diagnoses were lung neoplasia, lower airway disease, and cardiomyopathy (nine each). Other disease groups included mediastinal mass (eight), infection (seven), trauma (four), and hernia (three). • CT provided additional correct diagnoses in 28% (14/50) and additional information in 74% (37/50) of the cats. Additional correct diagnoses achieved only with CT were most common for cats with lower airway disease. |
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64-MULTIDETECTOR COMPUTED TOMOGRAPHIC ANGIOGRAPHY OF THE CANINE CORONARY ARTERIES |
• Esmolol, a b-1 adrenergic receptor antagonist, and sodium nitroprusside, an arteriolar and venous dilator, were administered to enhance visualization of the coronary arteries by reducing heart rate and creating vasodilation. The left main coronary artery with its three main branches and the right coronary artery were visualized and subdivided in 13 segments for evaluation. • The use of esmolol did not lead to the target heart rate of 60–65 beats/min. Nitroprusside had no significant effect on visualized length or diameter of the coronary artery branches. Coronary CTA is useful for the anatomic depiction of coronary artery branches in the dog. |
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ANATOMY OF EXTRAHEPATIC PORTOSYSTEMIC SHUNTS IN DOGS AS DETERMINED BY COMPUTED TOMOGRAPHY ANGIOGRAPHY |
• Six general shunt types were identified: splenocaval, splenoazygos, splenophrenic, right gastric-caval, right gastric-caval with a caudal shunt loop, and right gastric-azygos with a caudal shunt loop. Slight variations of tributary vessels were seen within some shunt classes, but were likely clinically insignificant. • Two shunt types had large anastomosing loops whose identification would be important if surgical correction were attempted. |
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CLINICAL RELEVANCE OF ABNORMAL SCINTIGRAPHIC FINDINGS OF ADULT EQUINE RIBS |
• Thirteen (52%) scintigraphic lesions involved the first rib; four were located immediately dorsal to the sternal articulation, eight were near the costochondral junction and one was at the costovertebral junction. Six (24%) scintigraphic rib lesions involved ribs 2–8; one was located immediately dorsal to the sternal articulation, three were at the costovertebral junction and two were near the costochondral junction. Six (24%) scintigraphic rib lesions involved the mid-portion (five) or costovertebral junction (one) of ribs 9–18. The 20 horses were divided into three groups based on the clinical relevance of the scintigraphic findings. Group 1 (n 1⁄4 3) horses had clinical signs attributed to a rib abnormality; Group 2 (n 1⁄4 6) horses had a rib abnormality that was a plausible explanation for clinical signs; Group 3 (n 1⁄4 11) horses had clinical signs that could not be attributed to a rib abnormality. • For horses with cranial rib abnormalities, a modified lateral scintigraphic image with the ipsilateral limb pulled caudally and a left (right) 451 caudal–right (left) radiograph facilitated the diagnosis. |
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CONTRAST-ENHANCED ULTRASONOGRAPHY OF THE NORMAL CANINE ADRENAL GLAND |
• Six healthy female Beagles were injected with an intravenous bolus of a lipid-shelled contrast agent (SonoVue). The aorta enhanced immediately followed by the renal artery and then the adrenal gland. Adrenal gland enhancement was uniform, centrifugal, and rapid from the medulla to the cortex. When maximum enhancement was reached, a gradual homogeneous decrease in echogenicity of the adrenal gland began and simultaneously enhancement of the phrenicoabdominal vessels was observed. • While enhancement kept decreasing in the adrenal parenchyma, the renal vein, caudal vena cava, and phrenicoabdominal vein were characterized by persistent enhancement until the end of the study. |
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CONTRAST-ENHANCED ULTRASONOGRAPHY OF THE SMALL BOWEL IN HEALTHY CATS |
• Subjectively,a rapid intense enhancement of the serosal and submucosal layers was followed by gradual enhancement of the entire wall section during the early phase. At peak enhancement, there was a subjective loss of demarcation between intestinal wall layers. In the late phase, there was a gradual wash out of signal from the intestinal wall. Submucosal wash out occurred last. |
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CORRELATION OF ULTRASOUND FINDINGS, LIVER AND SPLEEN CYTOLOGY, AND PROGNOSIS IN THE CLINICAL STAGING OF HIGH METASTATIC RISK CANINE MAST CELL TUMORS |
• Seven dogs had mast cell infiltration of the spleen, liver, or both. The sensitivity of ultrasound for detecting mast cell infiltration was 43% for the spleen and 0% for the liver. • Dogs with positive cytologic evidence of mast cell infiltration to spleen, liver, or both had significantly shorter survival (100 vs. 291 days) than dogs without evidence of mast cell infiltration |
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IMAGING DIAGNOSIS—HETEROBILHARZIA AMERICANA INFECTION IN A DOG |
• An approximately three-year-old mixed breed female dog was evaluated for peritoneal effusion, anorexia, intermittent vomiting, and diarrhea. Radiographically, there was mineralization of the wall of small intestinal segments. • Sonographic findings were consistent with multisystemic mineralization of liver, small intestinal wall, and pancreas. Multifocal granulomas containing schistosome eggs (Heterobilharzia americana) were identified histologically. The mineralization pattern described herein is an uncommon presentation of severe diffuse heterobilharziasis in a dog |
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IMAGING DIAGNOSIS—METASTATIC ADRENAL PHEOCHROMOCYTOMA IN A DOG |
• A 10-year-old Akita mix became acutely paraplegic. Upon magnetic resonance imaging, multiple, slightly T2-hyperintense, T1-isointense extradural masses, relative to spinal cord were found in the vertebral canal. • The retroperitoneal masses had mixed T2-signal intensity. The contrast enhancement pattern for the spinal masses was both homogenous and heterogenous. The diagnosis was metastatic pheochromocytoma. |
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IMAGING FINDINGS IN DOGS WITH CAUDAL INTERVERTEBRAL DISC HERNIATION |
• All dogs were 7 years of age at the time of presentation, with one neutered male and three neutered females. Breeds included one Beagle, one Bassett hound, and two large, mixed breed dogs. All dogs had tail pain on manipulation, two had pain during defecation, and two maintained an abnormal tail position. Three dogs had radiographs in which mineralization within the disc space was apparent. Two of these dogs also had mineralization within the vertebral canal. • Three dogs underwent MRI, which was characterized by varying degrees of disc herniation and nerve root compression at Cd1–Cd2 |
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RADIOGRAPHIC DIAMETER OF THE COLON IN NORMAL AND CONSTIPATED CATS AND IN CATS WITH MEGACOLON |
• Radiographs of 50 cats with no history of gastrointestinal disease were evaluated to establish a normal reference range for radiographic diameter of the feline colon. Thirteen cats with constipation and 26 with megacolon were also evaluated and compared with the normal cats to characterize the accuracy of the reference range and to identify a cutoff to distinguish constipation from megacolon. • A ratio of maximal diameter of the colon to L5 length was the most repeatable and accurate measurement. A ratio o1.28 is a strong indicator of a normal colon (sensitivity 96%, specificity 87%). A value 41.48 is a good indicator of megacolon (sensitivity 77%, specificity 85%). |
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RELIABILITY OF T2-WEIGHTED SAGITTAL MAGNETIC RESONANCE IMAGES FOR DETERMINING THE LOCATION OF COMPRESSIVE DISK HERNIATION IN DOGS |
• The sites of compression were localized correctly from the sagittal images in 89.8% of dogs. If only the most significant lesions were accounted for, the percentage increased up to 95.2%. In 54.9% of the readings with incorrect localization, the actual compressive site was immediately adjacent to the one suspected from review of the sagittal images. The frequency of correct localization was higher in the cervical region, and was increased by examination of the SSFSE slab. • The most common cause of disagreement was the presence of multiple degenerate bulging disks. Based on these results we recommend obtaining transverse images across the entire segment when multiple bulging disks are present. |
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STANDING LOW-FIELD MAGNETIC RESONANCE IMAGING APPEARANCE OF NORMAL COLLATERAL LIGAMENTS OF THE EQUINE DISTAL INTERPHALANGEAL JOINT |
• Low-field MR imaging characteristics of normal collateral ligaments of the DIJ of cadaver feet were corroborated with high-field MR imaging and histologic examination to exclude desmopathy. The size and shape of the collateral ligaments of the DIJ was similar among limbs; however, the signal pattern of the ligaments varied depending on the segment of the ligament being assessed and the MR sequence used. • In limbs positioned within the magnet as recommended for clinical MR imaging, collateral ligaments of the DIJ have heterogeneous signal pattern with a peripheral region of increased signal intensity at the level of the middle phalanx that can be confused with a desmopathy. • The results of this study support the presence of magic angle effect within the axial margin of the CL of the DIJ at the level of fiber divergence within the proximal to mid-portion of the ligament. |
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STARRY SKY HEPATIC ULTRASONOGRAPHIC PATTERN IN HORSES |
• The horses had various clinical signs, with weight loss and anorexia reported most commonly. Liver size and parenchymal echogenicity were normal in most horses. The hyperechoic foci fre- quently caused acoustic shadowing. Biliary dilation was noted rarely. The ultrasonographic pattern was the result of numerous fibrosing hepatic granulomas in all horses evaluated histologically • Fifteen horses had an additional disease that was identified as the apparent cause of clinical signs. Three horses had primary hepatic disease while 12 had diseases of other body systems. Therefore, the starry sky ultrasonographic pattern is likely incidental in most horses and not clinically significant. |
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THE USE OF COMPUTED TOMOGRAPHIC THREE-DIMENSIONAL RECONSTRUCTIONS TO DEVELOP INSTRUCTIONAL MODELS FOR EQUINE PELVIC ULTRASONOGRAPHY |
• Ultrasonographic examinations were simulated by moving transducers on the skin surface and rectally to produce images of pelvic structures. Camera angles were manipulated to best illustrate the transducer–beam–bone interface. Fractures were created in multiple configurations. |
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THE USE OF DIFFUSION TENSOR IMAGING TO EVALUATE THE SPINAL CORD IN NORMAL AND ABNORMAL DOGS |
• In normal dogs, the DTI sequence was characterized by normal fiber tracking with no statistical difference between the four sections of spinal cord (P40.05). In the dogs with a spinal cord lesion, there was a significant difference in fractional anisotropy between the two groups (P 1⁄4 0.0003) and the ADC analysis statistical significance (P 1⁄4 0.048) at the caudal most site. • Based on these findings, DTI is a potentially useful method to evaluate the spinal cord in dogs |
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CLINICAL AND DIAGNOSTIC IMAGING FINDINGS IN HORSES WITH SUBCHONDRAL BONE TRAUMA OF THE SAGITTAL GROOVE OF THE PROXIMAL PHALANX |
• High-field or low-field magnetic resonance (MR) imaging confirmed the presence of a fissure fracture or subchondral and trabecular bone trauma. • Seven of eight lesions were located approximately midway between the dorsal and palmar cortices of the proximal phalanx; the eighth was sited more dorsally. Two horses underwent follow-up MR imaging and abnormal signal intensity persisted, with little change. |
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COMPARISON OF RADIOGRAPHIC AND SCINTIGRAPHIC FINDINGS OF THE SPINOUS PROCESSES IN THE EQUINE THORACOLUMBAR REGION |
• Radiographic and scintigraphic images of the thoracolumbar spine of 604 horses were graded. A radiographic grade for each spinous process (T8–L6) was assigned (0–7). The maximum radiographic grade for each horse was defined as the highest grade assigned to any spinous process; the total radiographic grade was the sum of all grades for each horse. A scintigraphic grade for each spinous process was determined (0–3). • The maximum scintigraphic grade for each horse was defined as the highest grade assigned to any spinous process; the total scintigraphic grade was the sum of all grades for each horse. • The caudal thoracic spine (T14–T17) was most frequently affected. There was a significant breed and age effect, with Thoroughbreds and older horses having higher total and maximum radiographic grades. The severity of the lesions of the spinous processes was significantly associated with the presence of osteoarthritis of the articular process joints. It was concluded that there is a wide range of radiographic abnormalities of the spinous processes seen in horses with or without back pain. There is an association between radiographic and scintigraphic grades of the spinous processes |
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CONTRAST HARMONIC ULTRASOUND APPEARANCE OF CONSECUTIVE PERCUTANEOUS RENAL BIOPSIES IN DOGS |
• Contrast harmonic ultrasound increases blood pool echo intensity, enhancing parenchymal lesions. Therefore, contrast harmonic ultrasound is a potential alternative screening method for postbiopsy renal lesions. More renal lesions were detected with contrast harmonic ultrasound (22/22) compared with conventional ultrasound (14/22). The majority appeared at week 0 as hypoechoic tract(s) (27/33), the other (6/ 33) as ill-defined areas or area/tract combination, all having variable size, shape, and echogenicity. • Seven tracts had a small subcapsular hematoma. In most kidneys, similar or gradual decrease of size and sharpness, and increased echogenicity was observed until normal appearance occurred at week 1 (1/22), week 2 (18/22), or week 3 (22/22) |
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CONTRAST MEDIA ENHANCEMENT OF INTRACRANIAL LESIONS IN MAGNETIC RESONANCE IMAGING DOES NOT REFLECT HISTOPATHOLOGIC FINDINGS CONSISTENTLY |
• In 15 lesions, there was no association between MR images and histologic findings. In particular, contrast enhancement was found within necrotic areas (10 areas) and ring enhancement was seen in lesions without central necrosis (five lesions). These findings imply that necrosis cannot be differentiated reliably from viable tissue based on postcontrast images. • Diffusion of contrast medium within lesions and time delays after contrast medium administration probably play important roles in the presence and patterns of contrast enhancement. Thus, histologic features of lesions cannot be predicted solely by contrast enhancement patterns |
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EFFECT OF CONTRAST MEDIUM INJECTION DURATION ON PEAK ENHANCEMENT AND TIME TO PEAK ENHANCEMENT OF CANINE PULMONARY ARTERIES |
• In conclusion, injection duration is a key feature in a CT angiography injection protocol. A protocol with an injection duration adjusted to the scan duration seems to be particularly suitable for veterinary applications where a population with great weight variability is studied • There was a significant correlation between time to peak enhancement and injection duration in both groups |
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EFFECT OF DELAYED ACQUISITION TIMES ON GADOLINIUM-ENHANCED MAGNETIC RESONANCE IMAGING OF THE PRESUMABLY NORMAL CANINE BRAIN |
• The observers found either no difference or poor agreement in identification of the nonvascular structures. Intraobserver agreement was very good with all vascular structures and most nonvascular structures. A degree of meningeal enhancement was a consistent finding. • The initial acquisition had higher enhancement characteristics and observer agreement for some structures; however, contrast-to-noise was comparable in the delayed phase or not significantly different. We provide baseline references and suggest that the initial T1w postcontrast sequence is preferable but not essential should a delayed postcontrast T1w sequence be performed. |
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EXPERT INTERPRETATION COMPENSATES FOR REDUCED IMAGE QUALITY OF CAMERA-DIGITIZED IMAGES REFERRED TO RADIOLOGISTS |
• Veterinary radiologists’ accuracy did not significantly differ between analog vs. camera-digitized images (P1⁄40.13) although sensitivity was higher for analog images. Radiologists’ interpretation of both digital and analog images was significantly better compared with the private veterinarians |
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IMAGING ASSESSMENT OF THE MODIFIED DOUBLE CONTRAST BARIUM ENEMA USING CARBOXYMETHYLCELLULOSE ON RADIOGRAPHY AND ULTRASONOGRAPHY IN DOGS |
• The modified barium enema using carboxymethylcellulose is useful for assessing the general morphology and mucosal layers of the colon simultaneously on radiographs and ultrasonographs |
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THE VALUE OF RADIOGRAPHIC SCREENING FOR METALLIC PARTICLES IN THE EQUINE FOOT AND SIZE OF RELATED ARTIFACTS ON LOW-FIELD MRI |
• Magnetic susceptibility artifact size, location and superimposition on clinically relevant anatomic structures can be predicted radiographically for particles larger than 1 mm. If metal debris cannot be removed, the least artifact-prone FSE sequences should be selected. |
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MAGNETIC RESONANCE IMAGING IN FOALS WITH INFECTIOUS ARTHRITIS |
• Four out of six foals with infectious arthritis had osseous lesions in MR images indicative of osteomyelitis and only 4/19 lesions were detected on digital radiographs. The three foals with noninfectious arthritis had no osseous lesions in MR images or radiographically • Osseous lesions in the epiphysis, metaphysis, and physis appeared in MR images as T2W, short tau inversion recovery, and proton density hyperintense foci with a hypointense halo. The same lesions appeared hyperintense in the 3D RSSG water excitation pulse sequence but lacked a surrounding hypointense halo. Most joints of foals with infectious arthritis had heterogenous signals within the synovial fluid whereas all of the nonseptic joints had homogenous synovial fluid signals. • MR imaging appears to be better than radiography in the detection of osseous lesions in foals diagnosed with infectious arthritis and may be a valuable screening test for the presence of osteomyelitis |
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IMAGING DIAGNOSIS—SPINAL CORD HEMANGIOMA IN TWO DOGS |
• A capillary hemangioma was of mixed intensity but predominantly T2-hyperintense and mildly T1-hyperintense to spinal cord with strong contrast enhancement. A cavernous hemangioma had a target-like appearance in both T1-weighted (T1w) and T2-weighted (T2w) images. In T2w images there was a small isointense center surrounded by a relatively large hyperintense area. In T1w images, there was a large isointense centre with a relatively small hyperintense periphery |
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IMAGING DIAGNOSIS—GASTRIC PNEUMATOSIS IN A CAT |
• Gastric wall thickening with intramural gastric air was detected radiographically and sonographically. Gastric ulceration with a focal necrotic area was seen endoscopically. At surgery, the stomach wall was emphysematous. • Clinical signs resolved following partial gastrectomy and medical management. |
