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66 Cards in this Set
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79 year old with prostate biopsy positive for Gleason 5 prostate cancer with PSA of 4.3 mg/nl. Bone scan shows single focus of increased uptake at L4. Diagnosis?
a. Degenerative spondylitis b. Metastasis c. Pott’s disease d. Hemangioma e. Schmorl's node |
Degenerative spondylitis
Likelihood of bone metastases is low in patients with newly diagnosed, untreated prostate cancer when the initial PSA level was less than 10 ng/ml, the number of positive biopsy cores was less than 2, tumor was confined to one lobe, or the Gleason score was less than 6. The NCCN recommends the use of bone scan only for patients with PSA level ≥ 10 ng/mL, Gleason ≥ 8, presence of symptoms consistent with bony metastases, or any clinical T3 or T4 prostate cancer. The incidence of a positive bone scan in men with a PSA level <10 ng/mL is <1%. In an acute setting, Schmorl’s node would be correct. |
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What is true giving recombinant TSH (Thyrogen) to a patient with highly suspected recurrent thyroid cancer prior to diagnostic I-131 test:
a. Equivalent to cessation/removal of thyroid hormone b. Approved for 131 therapy/treatment c. Given to patient with a previous normal scan after thyroid hormone removal d. Given daily 2 weeks prior to scanning e. Decreases specificity of I-131 study |
Equivalent to cessation/removal of thyroid hormone
Normally, thyroid hormone replacement is stopped prior to a scan. Alternatively, without stopping synthroid, we can elevate the TSH by giving it ourselves (thryogen). Recombinant human thyrotropin (rhTSH) is administered to raise serum thyrotropin levels to stimulate thyroid tissue so that radioiodine (I-131) scanning may be performed. The drug is given as a one day or two day protocol injected into the buttocks muscle. Very few side effects: transient headaches or nausea. Each dose should follow previous by about 24 hours. After final dose, blood test to measure TSH levels to see if it is high enough to perform a radioactive iodine scan. On the day after the last injection, the patient is given a tracer dose of radioactive iodine. The day after that, a whole-body scan is performed according to the usual procedure. |
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Gallium-67 is preferred over Indium-111 WBC scan for:
a. Disc space infection (spinal osteomyelitis) b. Osteomyelitis of foot in diabetic c. Lung infection d. IBD e. Colon infection f. Pelvic abscess |
Answer: Disc space infection (spinal osteomyelitis)
Indium is superior for: abdominal abscesses, Crohn’s, UC, pseudomembranous colitis, diverticulitis, ischemic/infarcted bowel, vascular graft infections, AV graft infections, all other osteomyelitis other than spinal, diabetic foot infections. As a general rule, Indium superior for intestinal infection. Gallium is better for: spinal and disc infections; FUO; TB and fungal infections, better for all pulmonary processes - Ga-67 citrate accumulates in virtually all pulmonary infections, inflammatory sites, and interstitial and granulomatous diseases, including PCP pneumonia and sarcoid. |
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Indium-111 WBC scan is preferred over Gallium-67 for:
a. vascular graft infection b. cardiac valve infection c. PCP lung infection d. vertebral osteomyelitis |
Answer: Vascular graft injection
Indium-111 labeled leukocytes can be used to diagnose surgical prosthetic graft infection. In-111 labeled leukocytes are not useful in making the diagnosis of subacute bacterial endocarditis. Ga-67 is the preferred agent for the scintigraphic evaluation of most pulmonary diseases and vertebral osteomyelitis. |
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Indium 111-WBC is better than Gallium 67 in the evaluation of which process:
A. PCP (lung infection) B. active phase of IBD C. spinal disc infection D. splenic abscess E. spinal osteomyelitis |
Answer: Active phase of IBD
Ga-67: pulmonary (pneumonia, sarcoid, drug toxicity); vertebral osteomyelitis; lymphoma, melanoma In-111 WBC: most all infections, except splenic abscess (high normal uptake in spleen); IBD; graft/prosthesis infections. Do splenic abscess with indium then follow with Tc99m-sulfur colloid and subtract out the spleen. |
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On a V/Q scan, 70% of perfusion goes to the right lung. Which of the following would be LEAST likely cause?
a. Large left effusion b. Mucus plug in the left mainstem bronchus c. Left pulmonary artery hypoplasia d. Right Blalock-Taussig shunt e. Radiopharmaceutical given with patient in LLD position |
Answer: Bronchogenic carcinoma
Bronchogenic carcinoma (23%), CHD (arterial disease including Swyer-James, PA agenesis, and shunt procedures like Blalock-Taussig for 8%), and hyperlucent/absent lung syndrome (8%, pneumonectomy, agenesis) are most common. PE is uncommon especially without contralateral defects (23%). |
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On a V/Q scan, 70% of perfusion goes to the right lung. Which of the following would be LEAST likely cause?
a. Large left effusion b. Mucus plug in the left mainstem bronchus c. Left pulmonary artery hypoplasia d. Right Blalock-Taussig shunt e. Radiopharmaceutical given with patient in LLD position |
Answer: Radiopharmaceutical given with patient in a left lateral decubitus position
If scintigraphy is performed in the left lateral decubitus position, mismatched patterns can result. But since PBF is gravity dependent, this would cause ↑ flow to the left lung. Unilateral lung perfusion- “SAFE POEM”: Swyer-James, Agenesis, Fibrosis (mediastinal), Effusion, Pneumonectomy/PTX, Obstruction, Embolus, Mucus plug. Blalock-Taussig (BT) shunt is a subclavian to pulmonary artery anastomosis used in TOF patients; the side opposite the aortic arch is typically used (e.g., normal left arch → right subclavian/PA anastamosis). Although 95% of 99mTc-MAA is extracted on the 1st-pass through the lung, a functioning BT shunt presumably has a large VSD, allowing initial bypassing of the pulmonary capillary bed. Some recalls state "right lateral decubitus" in which case BT shunt is correct answer! |
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On a V/Q scan, 70% of perfusion goes to the right lung. Which of the following would be LEAST likely cause?
a. Large left effusion b. Mucus plug in the left mainstem bronchus c. Left pulmonary artery hypoplasia d. Right Blalock-Taussig shunt e. Radiopharmaceutical given with patient in LLD position |
Answer: Radiopharmaceutical given with patient in a left lateral decubitus position
If scintigraphy is performed in the left lateral decubitus position, mismatched patterns can result. But since PBF is gravity dependent, this would cause ↑ flow to the left lung. Unilateral lung perfusion- “SAFE POEM”: Swyer-James, Agenesis, Fibrosis (mediastinal), Effusion, Pneumonectomy/PTX, Obstruction, Embolus, Mucus plug. Blalock-Taussig (BT) shunt is a subclavian to pulmonary artery anastomosis used in TOF patients; the side opposite the aortic arch is typically used (e.g., normal left arch → right subclavian/PA anastamosis). Although 95% of 99mTc-MAA is extracted on the 1st-pass through the lung, a functioning BT shunt presumably has a large VSD, allowing initial bypassing of the pulmonary capillary bed. Some recalls state "right lateral decubitus" in which case BT shunt is correct answer! |
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NRC guidelines require a medically reportable event to be called directly to a NRC official within how many days?
a. next business day (within one calendar day) b. within three calendar days c. within seven calendar days d. within 15 calendar days |
Answer: Next business day
§ 35.3045 Report and notification of a medical event. (c) The licensee shall notify by telephone the NRC no later than the next calendar day after discovery of the medical event. (d) By an appropriate method listed in § 30.6(a) of this chapter, the licensee shall submit a written report to the appropriate NRC Regional Office listed in § 30.6 of this chapter within 15 days after discovery of the medical event. (e) The licensee shall provide notification of the event to the referring physician and also notify the individual who is the subject of the medical event no later than 24 hours after its discovery. |
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NRC guidelines mandate that agreement states which are in charge of its own regulations do the following:
A. state's rules have to be more strict than NRC's rules b. state's rules have to be less strict than NRC's rules c. oversee all medical facilities in the state d. manage all by-products |
Answer: Manage all by-products
"NRC provides assistance to States expressing interest in establishing programs to assume NRC regulatory authority under the Atomic Energy Act of 1954, as amended. Section 274 of the Act provides a statutory basis under which NRC relinquishes to the States portions of its regulatory authority to license and regulate byproduct materials (radioisotopes); source materials (uranium and thorium); and certain quantities of special nuclear materials." |
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Which of the following will PET-CT fusion help with (FDG PET in correlation with CT would be helpful for):
a. differentiate esophagitis vs. esophageal cancer b. differentiate scar/radiation change vs. tumor recurrence c. differentiate ureter vs. paraaortic lymph node activity d. differentiate endometritis vs. endometrial cancer |
Answer: Differentiate scar/radiation change vs tumor recurrence
PET/CT is particularly valid in specific situations, such as differential diagnosis of indeterminate lesions at CT, differentiation of posttreatment changes from recurrent tumor, and monitoring the response to therapy. |
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Most useful for differentiating between recurrent brain tumor and radiation necrosis (FDG PET not an option):
A. N-13 PET (NH3 PET) B. Tl-201 SPECT C. Tc-99m ECD D. Tc-99m HMPAO E. Contrast-enhanced CT |
Answer: Thallium-201 SPECT
This question has been recalled as N-13 PET and NH3 PET, but not FDG-PET. Requisites talks about FDG-PET can distinguish radiation necrosis (hypometabolic) vs. tumor recurrence (hypermetabolic). Tl-201 is also useful for distinguishing tumor necrosis after radiation vs. active tumor (tumor viability after rradiation. N-13 is listed as a metabolic agent and perfusion agent used to study the myocardium. Tc99m HMPAO, Tc99m ECD, and I-123 IMP SPECT: Show decreased uptake in most primary and metastatic tumors; used for cerebral perfusion imaging, not tumor viability. |
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Which is most sensitive modality for cell receptor imaging:
a. PET b. SPECT c. CT d. MR e. US |
Answer: SPECT
This is probably referring to somatostatin receptor imaging, with octreotide, MIBG, etc., which is done with SPECT. SPECT images cell receptors with any of the various nuclear medicine imaging agents which bind to cell receptors i.e, octreoscan-somatostatin receptors. |
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In 111-pentoctreotide is MOST sensitive for which?
a. insulinoma b. medullary thyroid cancer c. adenocarcinoma of the lung d. gastrinoma |
Answer: Gastrinoma
If worded as above, the answer would be gastrinoma as octreoscan is 50% sensitive for insulinoma and medullary thyroid cancer but highly sensitive for carcinoid and gastrinoma. Prior recalls: Which tumor would octreoscan not be useful for imaging? This has been on prior recalls with the answer being adenocarcinoma of the lung as all the others are neuroendocrine tumors. |
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Which cardiac nuclear medicine imaging exam has the highest first pass myocardial extraction?
a. Rubidium-87 b. Thallium-201 c. Tc-99m sestamibi d. Tc-99m tetrofosmin |
Answer: Thallium-201
Thallium has first-pass extraction efficiency of 88%. You can remember "90% in 90 seconds." Sestamibi has 40% first-pass extraction. Tetrofosmin has "lower first-pass extraction than thallium." Advantages of Thallium over Technetium: 1) higher total accumulation in myocardium; 2) provides redistribution information; 3) well suited to assess viability. Advantages of Technetium over Thallium: 1) low radiation dose related to shorter half life allowing larger doses with less patient radiation; 2) excellent imaging charcteristics due to improved photon flux which means faster imaging and allows cardiac gating. Higher energy also means less attenuation from breast tissue/diaphragm. 3) no redistribution; 4) Imaging can occur later secondary to long half life, causing increased patient throughput. |
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Most suggestive of prosthetic hip infection on bone scan:
a. increased uptake around tip of prosthesis (femoral tip) b. increased uptake around femoral head and neck c. increased uptake around acetabulum d. normal uptake e. diffuse increased uptake around entire prosthesis |
Answer: Diffuse increased uptake around entire prosthesis
Loose prosthesis – uptake increased in the region of the greater and lesser trochanters and at the tip of the prosthesis. May also be seen as diffusely increased uptake around the acetabular component. Increased activity is due to remodeling of bone in response to movement of the prosthesis. Some increased uptake is expected as a normal healing response for 1 year after cemented prosthesis and 2-3 years of noncemented prosethesis. Baseline study 6 mo to one year following surgery is very useful. Infected prosthesis – activity is increased in the bone surrounding the prosthesis; tracer localizes in areas of infection and not in areas of remodeling or reactive bone. However , 3 pitfalls: (1) false negative studies may occur in low grade chronic osteomyelitis. (2) cellullits can be difficult to distinguish from septic arthritis. (3) False positive studies can result from normal radiolabeled WBC uptake in bone marrow around a prosthesis. Therefore, WBC and sulfur colloid marrow scanning is combined to avoid pitfalls. Infection is diagnosed only in areas of WBC uptake that are negative for marrow activity. |
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What is an advantage of Tc99m sulfur colloid bleeding scan over tagged RBC scan?
a. faster preparation time b. increased sensitivity for UGI bleed c. better for intermittent bleed d. delayed imaging can be repeated over 24 hours e. greater sensitivity than angiography |
Answer: Faster preparation time
Tc-99m Sulfur colloid: injected with rapid extraction by liver, spleen and BM (T1/2 of 3 min, most cleared from vascular system by 15 min). During ACTIVE bleeding, tracer extravasates at bleeding site with each recirculation, resulting in high target-to-background due to constant extravasation with simultaneous clearance. Time required: 20 min.ACTIVE bleeding is detected in first 5-10 min, with bleeding site a focal area of uptake that increases in intensity and MOVES thru GI tract during the study. Sulfur colloid is less sensitive than tagged RBC. Tagged RBC: can detect INTERMITTENT bleeds since site can be detected over longer time, dependent only on T1/2 of Tc-99m and stability of radiolabel. Longer prep time since labeling with Tc-99m sodium pertechnetate is required (20 min). In vivo and in vitro methods of labeling can be used. Sequential images acquired for 90 min. If neg, repeat 30 min acquisitions at 2-4 hrs and whenever active bleeding suspected up to 24 hrs. May also show sites that are not actively bleeding and define vascular structures. ACTIVE bleeding must be intraluminal, increase over time, and move thru GI tract. Very sensitive for lower GI bleed. Upper GI bleeds are more difficult to diagnose, glucagon may be helpful. Can detect rates as low as 0.1 mL/min; only 2-3 mL blood necessary for detection. Large multicenter study showed sens 93%, spec 95% (much higher than for Tc-99m SC). |
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Patient with lower GI bleed. Bleeding study done with both sulfur colloid and Tc labeled RBC’s. Sulfur colloid study was negative and RBC study positive. What explains these findings?
a. Intermittent bleeding in colon b. Bleeding at hepatic flexure |
Answer: Intermittent bleeding in colon
The disadvantage of sulfur colloid scanning is the potential masking of bleeding in the upper abdomen by activity in the liver and spleen. 99mTc-labeled RBC scanning does not have this problem. Bleeding is diagnosed when an abnormal focus of activity is seen. This activity increases over time and changes in position due to peristalsis. An advantage of 99mTc RBC scanning is that repeat imaging can be performed after an interval of as long as 24 hours. |
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At least one-third of which liver lesion takes up Tc sulfur colloid in Tc-99 m sulfur colloid liver/spleen scan:
a. Adenoma b. HCC c. FNH d. Hemangioma |
Answer: FNH
FNH usually shows uptake because it has Kupffer cells. Normal or increased uptake (only FNH has both Kupffer cells & bile ductules). Uptake is pathognomonic in up to 60% of cases. Adenoma: Tc sulfur colloid shows "cold" (photopenic) defect in 80%; uncommonly "warm": in 20% due to uptake in sparse Kupffer cells. HCC: Tc sulfur colloid of HCC in a cirrhotic liver seen as a cold defect and HCC in a noncirrhotic liver shows heterogeneous uptake. 70% of well differentiated HCC exhibited radioactivity up take, whereas only 30% of those moderately differentiated and none of those poorly differentiated were found to take up DISIDA. Up to 36-57% of HCC show radioactivity uptake. Hemangioma: no hepatocytes or Kupffer cells, so no uptake. |
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Sulfur colloid scan demonstrates areas of absent hepatic activity, EXCEPT with:
A. FNH B. Adenoma C. HCC |
Answer: FNH
FNH usually shows uptake because it has Kupffer cells. Normal or increased uptake (only FNH has both Kupffer cells & bile ductules). Uptake is pathognomonic in up to 60% of cases. Adenoma: Tc sulfur colloid shows "cold" (photopenic) defect in 80%; uncommonly "warm": in 20% due to uptake in sparse Kupffer cells. HCC: Tc sulfur colloid of HCC in a cirrhotic liver seen as a cold defect and HCC in a noncirrhotic liver shows heterogeneous uptake. 70% of well differentiated HCC exhibited radioactivity up take, whereas only 30% of those moderately differentiated and none of those poorly differentiated were found to take up DISIDA. Up to 36-57% of HCC show radioactivity uptake. Hemangioma: no hepatocytes or Kupffer cells, so no uptake. |
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Regarding PET scan, which of the following is TRUE?
a. small cell lung carcinoma shows uptake b. no uptake in sarcoid c. no uptake in TB d. no uptake in fungal disease e. uptake in 60% of malignant nodules (60% malignancy is detectable) |
Answer: Small cell lung cancer shows uptake
The overall sensitivity and specificity of FDG PET are 92% and 90%, respectively, for detection of malignancy in nodules between 0.7 and 4 cm in diameter. Granulomas that occur in patients with sarcoidosis, tuberculosis, histoplasmosis, aspergillosis, and coccidioidomycosis as well as Mycobacterium avium-intracellulare infection and other infectious processes such as pneumonia may result in false-positive findings. |
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How is DISIDA processed in the liver?
a. active uptake by hepatocytes, conjugated, then excreted b. active uptake by hepatocytes, not conjugated, then excreted c. passive uptake reticuloendothel cells, conjugated, excreted d. active uptakereticuloendoth cells, not conjugated, excreted |
Answer: Active transport uptake, not conjugated and excreted into bile
The important point here is DISIDA is not conjugated. These radiopharmaceuticals are rapidly removed from the circulation by active transport into the hepatocytes and secreted into the bile canaliculi and then into the biliary radicles, bile duct, gallbladder and small intestine. |
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One hour post renal transplant, renal scintigraphy (MAG 3) with absolutely no uptake. Diagnosis?
a. Cyclosporine b. ATN c. Obstruction d. Hyperacute rejection e. Accelerated acute rejection |
Answer: Hyperacute rejection
Immediate to 1st 48 hours: Hyperacute rejection, RVT, discordant size Days 2-7: accelerated acute rejection, ATN (shows progressive tracer uptake with MAG3 and rapid washout with DTPA), RVT > 1 week post-op: acute rejection, ATN Delayed: Chronic rejection, drug toxicity, obstruction, infection, extrinsic compression |
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HMPAO scan (PET) demonstrating decreased flow (metabolism) in bilateral parietal and (posterior) temporal lobes. What is the diagnosis?
a. Niemann Pick disease b. Huntington's disease c. Alzheimer’s disease d. Pick's disease e. HIV |
Answer: Alzheimer's disease
Tc99m HMPAO reflects flow/blood perfusion to brain and can be used in dementia: Alzheimer’s - bilateral decreased PET, SPECT in temporal and parietal lobes Multiinfarct dementia - multiple, bilateral, randomly distributed cortical perfusion defects that follow vascular territories. The basal ganglia, motor, and sensory cortices involved (spared in Alzheimer's). Parkinson’s - bilateral posterior parietal/temporal defects indistinguishable from Alzheimer's Pick’s disease: is frontotemporal HIV findings on SPECT are that of patchy or multifocal cortical and subcortical perfusion deficits. Niemann Pick is frontal lobes Huntington's in decreased caudate nucleus, basal ganglia, striatal metabolism. |
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Regarding I-131 therapy, which is TRUE?
a. Causes leukemia in 5% b. Causes pulmonary fibrosis in those with lung metastasis c. Contraindicated if < 18 years d. Can be given as an outpatient (2005 version) |
Answer: Causes pulmonary fibrosis in those with lung metastasis
Guidelines regarding maximum activity which can safely be administered are: 1. Blood dose should be no more than 200 rads (2 Gy). 2. Retained whole body activity of no more than 120 mCi (4440 MBq) at 48 hours (or 80 mCi (2960 MBq) in patients with lung metastases to avoid potential pulmonary fibrosis. The increased risk of leukemia is 0.5%. Patients at risk are age > 50 and have received a dose of approximately 900 mCi. The risk is greatest when this large dose has been given over a short period of time (6 to 12 weeks). These patients have usually received a blood dose greater than 200 rads. In the past, patients were required to be hospitalized and in isolation after I-131 radioablation therapy until the dose rate from the patient was <5 mrems/hr, or the retained activity in the patient was <30 mCi. Patients can now be treated on an outpatient basis providing that certain exposure limits are maintained for individuals that may have contact with the patient (limit of 0.5 rem (5 mSv) TEDE to an individual due to radiations from the released patient). |
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NRC regulations specify that the activity of an administered dose of a radiopharmaceutical must be within what range of the prescribed (or measured) dose?
a. 5% b. 10% c. 15% d. 20% e. 25% |
Answer: 10%
The NRC requires that radiopharmaceutical activity be assayed to an accuracy of +10% of the prescribed dose before patient administration. A “medical event” occurs if two conditions are met: (1) One or more of the following representative incidents occur: the dose administered to a patient differs from prescribed dose by at least 20 percent, wrong drug is administered, the drug is administered by wrong route, dose is administered to wrong individual, patient receives a dose to a part of body other than intended treatment site that exceeds by 50 percent or more the dose expected by proper administration of the prescription, a sealed source used in the treatment leaks. AND (2) The difference between the dose administered and the prescribed dose exceeds one of the reporting limits contained in the NRC’s regulations. |
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In a patient with stage II breast cancer, what is the true positive rate of a bone scan (PPV of the bone scan?
a. 3% b. 10% c. 30% |
Answer: 3%
Stage 1: 0.5 % (Bone scans are thus generally not performed on Stage 1 and 2 patients.) Stage 2: 2-3% Stage 3: 8 % Stage 4: 13 % |
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FDG PET in heart is useful for diagnosing the following:
a. hibernating myocardium b. amyloid c. sarcoid d. ischemia |
Answer: Hibernating myocardium
FDG PET is gold standard for evaluating hibernating myocardium. |
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A patient presents with atypical chest pain and demonstrates abnormal wall motion in the lateral wall on imaging. A N13 PET demonstrates decrease radiotracer uptake in this region (no perfusion on ammonia PET). FDG PET demonstrates radiotracer uptake (hot on FDG PET). What is the likely cause:
a. Hibernating myocardium b. Stunned myocardium c. Infarct d. Normal tissue |
Answer: Hibernating myocardium
Myocardial perfusion is assessed with N13-ammonia, rubidium-82, or O15-labelled water. FDG is a measure of glucose metabolism. A normal perfusion and FDG uptake, or reduced perfusion with enhanced FDG uptake (mismatch pattern), indicates viable myocardium. Conversely, a concordant reduction in FDG uptake and myocardial perfusion (match pattern) is indicative of scar tissue. Hibernating myocardium is chronic ischemia to a region of myocardium resulting in decreased perfusion with preservation of metabolism in this region. Hibernating myocardium is salvageable with revascularization and represents physiologic down regulation of contractile function secondary to stenotic/occluded coronary arteries to protect myocytes from irreversible damage. NI3 will be DECREASED but F18 will be NORMAL Stunned myocardium is global ventricular dysfunction with preserved perfusion and metabolism. It represents depressed contractile function in presence of normal flow, may be secondary to repetitive ischemic episodes (see if commonly after a revascularization procedure. N13 and F18 are NORMAL. Infarct: Both N13 and F18 would be ABNORMAL (decreased) Normal tissue: Both N13 and F18 would be NORMAL |
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80-yo female, 3-years s/p MI and 80% LAD stenosis. In anterior septal wall, there is decreased ammonium PET uptake but increased FDG uptake on PET scan. The anterior septal wall is hypokinetic. Diagnosis?
A. Stunned myocardium B. Hibernating myocardium C. Infarction D. Scar |
Hibernating myocardium
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Tc sestamibi cardiac study that shows a fixed defect. There is uptake on F18-FDG. The most likely cause is:
a. Stunned myocardium b. Scar c. Hibernating myocardium |
Answer: Hibernating myocardium
Hibernating myocardium is the result of severe coronary artery stenoses or partially reopened occlusions producing chronic hypoperfusion and ischemia. These areas present as segments of decreased perfusion and absent or diminished contractility, even when the patient is in a resting state. Because the myocardium is ischemic, but still viable there will be F18-FDG uptake. |
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What is the most important factor for finding the GI bleeding site when performing a Tc 99 tagged RBC study?
a. timing of scan b. amount of tracer c. delayed 24 hour imagine |
Answer: Timing of scan
Timing of scan is most important. Must visualize tracer in bowel that moves over time. Tagged RBC scans are superior to sulfur colloid with better sensitivity and specificity. The advantage is the ability to image over a prolonged time period. Sulfur colloid still has a limited role in patient who is actively bleeding and clinically unstable, the 20 minut study will be positive and info valuable to IR. |
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Cholecystokinin in a HIDA scan does all the following EXCEPT:
a. increase bile flow b. increases sensitivity for chronic cholecystitis c. it shortens time for diagnosis of acute cholecystitis d. increases sensitivity for acute cholecystitis in hyperalimentation |
Answer: Shortens time for diagnosis of acute cholecystitis (FALSE)
CCK: recommended IV dose is 0.02 mcg/kg infused over 30-60 min (bolus may cause GB neck spasm). CCK causes increased production of hepatic bile and stimulates the contraction of the gallbladder and relaxation of the Sphincter of Oddi, resulting in the delivery of bile into the duodenum. GB contraction is threshold dependent and commences once the serum CCK increases above that threshold. Indications for CCK before HIDA are to empty the GB in a patient fasting > 24 hours and to diagnose sphincter of Oddi dysfunction. After HIDA, CCK is used to differentiate common duct obstruction from normal variation. It is also used to exclude acute acalculus cholecystitis if the gallbladder fills, diagnose chronic acalculus cholecystitis, and confirm or exclude chronic calculus cholecystitis. Caution is indicated in giving CCK after the patient has received morphine sulfate because morphine’s pharmacological effect may last 4-6 hours and counteract the effect of CCK. An adequate response is 35% or greater emptying (accepted normal GBEF is >= to 35%). CCK does increase sensivity for cholecystitis associated with hyperalimentation (acalculous cholecystitis). |
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Rim of increased counts around GB fossa of liver in cholecystitis:
A Due to increased blood flow to inflamed liver B Due to increased activity in gallbladder wall C Seen in 75% of cases of acute cholecystitis |
Answer: Due to increased blood flow to inflamed liver
Increased hepatic uptake is found in 25% with acute cholecystitis, identifying patients at a later stage of the disease. Pathophysiology: First, blood flow increases to the inflamed liver adjacent to the GB, and the inflammatory process in the GB wall can spread to the adjacent normal liver. The increased blood flow and the high liver extraction efficiency of the radiopharmaceutical result in increased uptake. Second, regional clearance may be delayed because of the edema and inflammation of biliary canaliculi. |
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Spatial resolution in PET (and dual headed SPECT) is determined by what?
a. Detector size b. Detector quantum efficiency c. Dose of radiotracer d. Scan time |
Answer: Detector size
The intrinsic properties of the detectors determine spatial resolution. Detector size determines the spatial resolution in PET. PET resolution is limited by physical parameters such as scatter, counting statistics, positron range and patient motion, as well as by the detector array geometry and the implemented acquisition protocol. While it is usually the case that increasing count statistics (i.e. more dose or longer imaging time) increases resolution, with most PET imaging the maximum dose that the system can handle is already being used (limited by detector dead time). |
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Which is true regarding indium octreotide study?
a. Should always use low energy, parallel hole collimator b. Uptake in thyroid and salivary glands is pathologic c. Can be falsely positive in granulomatous disease d. Allergies commonly prevent the study from being performed |
Answer: Can be falsely positive in granulomatous disease
Octeotride scans use a medium energy, parallel hole (high resolution) collimator. They are labeled with either indium-111 or iodine-123. Serum half life is 6 hours. In the absence of tumors, the distribution is to the kidneys, bladder, spleen, liver, gallbladder, and thyroid. Thus, uptake in thyroid and salivary glands is normal. Octreotide is a synthetic octapeptide with action similar to somatostatin. Somatostatin is inhibitory in nature on a variety of neuroendocrine cells. Thus, octreotide scans are positive in tumors with somatostatin receptors: 1. Neuroendocrine tumors or APUDomas such as pituitary adenoma, gastric tumors (carcinoid, gastrinoma, insulinoma pheochromocytoma, and medullary thyroid cancer and small cell lung cancer). 2. CNS tumors: astrocytoma, meningioma, neuroblastoma. 3. Other: breast, lung, lymphoma, and renal cell cancer. Octreotide can also be used to treat symptoms of metastatic carcinoid and VIP tumors and to suppress GH in acromegaly. Octreotide is also taken up by activated lymphocytes, such as in granulomas, lymphoma, and autoimmune disease. Therefore, false positives are seen with ganulomas (TB, sarcoid), Crohn’s, UC, and RA. |
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Thyroid cancer LEAST likely to be treated with I-131?
a. Papillary thyroid CA b. Follicular thyroid CA c. Mixed papillary-follicular thyroid CA d. Medullary thryoid CA e. Hurthle cell CA |
Answer: Medullary
Medullary and anaplastic thyroid cancer is resistant to I-131 treatment. Anaplastic thyroid CA was not listed as an answer choice. Medullary thyroid cancer does not arise from this C-cells of thyroid. Therefore, radioactive iodine therapy is not useful for the treatment of medullary thyroid cancer. |
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In optical imaging, all of following are considered in optical attenuation coefficient except:
a. intensity of incident light b. depth that travels c. molecular composition of tissue d. density of tissue |
Intensity of incident light
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HIV patient has fever, shortness of breath, and multiple pulmonary nodules (bilateral infiltrates). Gallium scan shows no uptake (negative scan). What is it?
a. Kaposi’s sarcoma b. PCP c. Lymphoma d. Septic emboli e. MAI |
Answer: Kaposi's sarcoma
Kaposi’s Sarcoma does not demonstrate uptake on gallium scans. Gallium is sensitive for lung PCP, lymphoma, and melanoma. Kaposi sarcoma diagnosed with sequential thallium and gallium scans. These scans demonstrated abnormal increase of pulmonary thallium uptake, whereas the gallium uptake was negative. |
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Utility of PET in breast cancer:
a. evaluate/follow response to treatment b. nodal staging c. screening for high risk patients d. screening for normal risk patients e. evaluate for malignancy in a known breast lesion |
Evaluate/follow response to treatment
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TRUE regarding the pleural stripe sign in V/Q scan?
a. Indicates peripheral perfusion defect b. Cannot be interpreted in presence of small bilateral pleural effusions c. Commonly seen in patients with COPD d. Indicates evidence of perfusion in periphery of the pleura e. Indicates presence of a pleural effusion |
Answer: Commonly seen in patients with COPD
The stripe sign is described as an area of hypoperfusion separated from the peripheral lung border by a stripe of normal parenchyma. Pathologies resulting in stripe sign are uncertain. Stripe sign is rarely seen in pulmonary disorders other than pulmonary emphysema. The presence of stripe sign was significantly associated with the history of smoking in 72% of the cases; peripheral lung tissue is less susceptible to the emphysematous changes caused by smoking. |
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TRUE about Plummer's disease and I-123 uptake scans?
a. Single hot nodule with decreased function in the rest of the thyroid is diagnostic of an autonomous functioning nodule b. Dose is higher for Plummer's than for Graves disease c. Graves disease is less common than Plummer's disease d. Thyroid function tests are necessary to discern whether there a hot nodule is autonomous e. Multiple hot nodules is diagnostic of Plummer's disease f. Single hot nodule can rarely represent a well-differentiated thyroid cancer |
Answer: Thyroid function tests are necessary to discern whether there the nodule is autonomous, A single hot nodule can rarely represent a well-differentiated thyroid cancer
Graves disease is most common hyperthyroidism. Plummer's disease (single hyperfunctioning nodule)/toxic multinodular goiter (mult hyper nodules) is second. Treatment dose of I 131 for Plummer's/TMG is higher than for Graves'. In order for nodule to be considered autonomous (permanently "on"), the TSH must be supressed. For Plummer's disease, the patient needs to be thyrotoxic with a goiter/thyromegaly. The term toxic refers to whether or not the patient has symptoms. 1% of well differentiated thyroid cancer can present as a single hot nodule. |
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Regarding Plummers disease and Graves, which is TRUE?
a. Plummers is more common than Graves b. Need larger I 131 dose to treat Graves than Plummers c. More likely to have post-treatment hypothyroidism with Plummers mor than Graves (I may have these switched) d. May both have multiple nodules on thryroid imaging e. Suppression of normal functioning thyroid tissue in both (either disease can present with an autonomous nodule) |
Answer: May both have multiple nodules on thryroid imaging
Plummer’s disease = toxic nodular goiter: I-131 dose is 25-29 mCi, leading to hypothyroidism in 5-30%. Grave’s disease: I -131 dose is 80-120 uCi, leading to hypothyroidism in 5-30%. Graves is more common, has no normal tissue. Hypothyroidism is more common after treatment for Grave’s Disease. Graves is the most common cause of hyperthyroidism and consists of diffuse hypertrophy of the gland thought to be secondary to an autoimmune process. Plummer’s Disease (Toxic Nodular Goiter) consists of scattered nodular foci of autonomously functioning tissue with suppression of adjacent normal tissue that develops gradually over time. Gland size is larger with Plummer’s and requires higher doses of I131. Grave’s disease associated with younger age, exophthalmos, rapidly developing hyperthyroidism, and more severe disease. |
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An octreotide scan is good for all of the following EXCEPT:
a. Neuroblastoma b. Pheochromocytoma c. Adrenal Adenoma d. Medullary thyroid CA |
Answer: Adrenal adenoma
An important disadvantage of octreoscan is its persistent high kidney activity, which makes interpretation of the adjacent adrenal gland more difficult In other years (1998, 2000), adrenal adenoma was not a choice. In those years the correct answer (NOT detected by octeotide scan) was renal cell carcinoma. Octreotide scan is not used for adrenal adenoma. Adrenocortical scintigraphy is performed with NP-59. |
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In a Meckel's scan, which agent can be given to suppress secretion of technetium from gastric cells (which agents will cause decreased secretion and increased uptake)?
a. Pentagastrin b. Cimetidine c. Phenobarbital |
Answer: Cimetidine
Cimetidine, pentagastrin, and glucagon can all help in evaluating for ectopic gastric mucosa. Cimetidine is an H2 blocker which blocks outflow of pertechnetate from ectopic gastric mucosa. Pentagastrin stimulates uptake of pertechnetate by gastric mucosa. Glucagon decreases small bowel motility, anti-peristaltic affect that can prevent washout. Phenobarbital is used in pediatric evaluation of neonatal hepatitis vs biliary atresia. It maximizes IDA sensitivity by activating liver excretory enzymes. |
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Appearance of cavernous hemangioma on sulfur colloid imaging:
A. most lesions are hot compared to liver B. increased flow is noted during early angiographic phase C. demonstrate gradual filling in on delayed imaging D. cold defect |
cold defect
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Which is TRUE regarding lytic mets and bone scan:
a) can often see lytic mets b) have to have tumor uptake to detect c) flare phenomenon indicates progression of disease d) vascularity is not important for diagnosis |
Vascularity is not important for diagnosis
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What is most characteristic of three
phase bone scanning of shin splints: A. hot on all three phases B. increased flow with decreased activity on blood pool and delayed images C. no increased flow or blood pool activity but hot on delayed images D. cold on all images E. bone scanning plays no role in its evaluation |
Answer: No increased flow or blood pool activity but hot on delayed images
The characteristic scintigraphic finding is an elongated region of moderate to intense radiotracer up-take along the posteromedial or anterolateral tibial cortex on the delayed bone scan. The abnormal activity is best visualized on the lateral view. In contrast to the acute stress fracture, the arterial and blood pool phases are normal. Also, shin splints are always associated with negative radiographs. Also, shin splints do not progress to stress fracture. Characteristic findings on scintigraphy are normal flow and blood-pool images, but linear longitudinal uptake on delays. Result of traction periostitis. A stress fracture will show focal uptake that is hot on all three phases. |
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Which does NOT result in increased focal uptake within the liver on Tc sulfur colloid imaging?
A. FNH B. Budd Chiari syndrome C. Regenerative nodules D. SVC syndrome E. Portal vein thrombosis |
Answer: Portal vein thrombosis
DDx of focal "hot spot": Budd-Chiari (hepatic vein thrombosis); caudate lobe (posterior), SVC obstruction: quadrate (anterior), hemangioma, Focal nodular hyperplasia, cirrhosis (regenerating nodules), IVC obstruction (if leg injection is performed) |
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Which would NOT be expected to produce focal areas of heterogeneous uptake on delayed Tc-99MDP scintigraphy:
a. Pagets disease b. Osteopoikilosis c. Metastatic neuroblastoma d. Multiple enchondromas |
Answer: Osteopoikilosis (none), multiple enchondromas (homogeneous uptake) (NOT associated)
Enchondromas are more homogeneous, having only increased or normal uptake. DDx for multiple hot foci (in decreasing order of frequency) is: mets > arthritis > trauma, osteoporotic insufficiency fx > Pagets > other metabolic bone dz, osteomyelitis > fibrous dysplasia, multiple enchondromas, infarction. GCTs: multicentric involvement is an unusal event that has been documented in only a limited number publications; frequency is 0.5–5%, multicentric GCTs may appear simultaneously or metachronously. |
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Which would NOT be expected to produce focal areas of heterogeneous uptake on delayed Tc-99MDP scintigraphy:
a. Pagets disease b. Osteopoikilosis c. Metastatic neuroblastoma d. Multiple enchondromas |
Answer: Osteopoikilosis (none), multiple enchondromas (homogeneous uptake) (NOT associated)
Enchondromas are more homogeneous, having only increased or normal uptake. DDx for multiple hot foci (in decreasing order of frequency) is: mets > arthritis > trauma, osteoporotic insufficiency fx > Pagets > other metabolic bone dz, osteomyelitis > fibrous dysplasia, multiple enchondromas, infarction. GCTs: multicentric involvement is an unusal event that has been documented in only a limited number publications; frequency is 0.5–5%, multicentric GCTs may appear simultaneously or metachronously. |
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7 months pregnant patient with history of breast CA now has bone pain in femur. TRUE regarding NM bone scan?
A. Should not be done because of the risk to the fetus. B. Should not be done because already known to have CA. C. Should be done. |
Answer: Should be done
Risk of radiation to a third trimester fetus is less than risk of untreated metastases in the mother. |
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7 months pregnant patient with history of breast CA now has bone pain in femur. TRUE regarding NM bone scan?
A. Should not be done because of the risk to the fetus. B. Should not be done because already known to have CA. C. Should be done. |
Answer: Should be done
Risk of radiation to a third trimester fetus is less than risk of untreated metastases in the mother. |
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A 60 year-old man is 4 years status post RCA CABG (non-dominant RCA). His immediate post-operative studies showed normal wall motion without infarct or ischemia. He now presents with a reversible posterior wall defect on thallium imaging. Most likely diagnosis?
a. Graft occlusion b. Native RCA occlusion proximal to the graft c. Native RCA occlusion distal to the graft d. New left coronary artery/LAD ischemia e. Circumflex ischemia f. Infarct |
Answer: New circumflex ischemia
Since the defect is a reversible one, the lesion must be ischemic and not an infarct. The LAD supplies the anterior heart wall. A graft occlusion would likely produce an irreversible wall defect. First: a dominant coronary artery is one that gives rise to the posterior descending artery, which supplies the posterior wall, the diaphragmatic aspect of the LV & most of the interventricular septum. In 80% the dominant artery is the RCA, in 10% the LCA, and in 10% both (codominance). In this case, the patient had a non-dominant RCA, meaning that the posterior wall was either partially or completely supplied by the LCA. Pure posterior wall infarcts are extremely rare. With posterior wall reversible defect is likely more posterolateral in distribution. This therefore likely represents new left circumflex disease. Coronary artery distributions: LCx – posterolateral RCA – posteroinferiorseptal LAD – anterior PDA - inferiorapical |
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A 60 year-old man is 4 years status post RCA CABG (non-dominant RCA). His immediate post-operative studies showed normal wall motion without infarct or ischemia. He now presents with a reversible posterior wall defect on thallium imaging. Most likely diagnosis?
a. Graft occlusion b. Native RCA occlusion proximal to the graft c. Native RCA occlusion distal to the graft d. New left coronary artery/LAD ischemia e. Circumflex ischemia f. Infarct |
Answer: New circumflex ischemia
Since the defect is a reversible one, the lesion must be ischemic and not an infarct. The LAD supplies the anterior heart wall. A graft occlusion would likely produce an irreversible wall defect. First: a dominant coronary artery is one that gives rise to the posterior descending artery, which supplies the posterior wall, the diaphragmatic aspect of the LV & most of the interventricular septum. In 80% the dominant artery is the RCA, in 10% the LCA, and in 10% both (codominance). In this case, the patient had a non-dominant RCA, meaning that the posterior wall was either partially or completely supplied by the LCA. Pure posterior wall infarcts are extremely rare. With posterior wall reversible defect is likely more posterolateral in distribution. This therefore likely represents new left circumflex disease. Coronary artery distributions: LCx – posterolateral RCA – posteroinferiorseptal LAD – anterior PDA - inferiorapical |
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Which of the following thyroid iodine uptake curves does NOT correlate with the disease?
A. subacute thyroiditis B. hypothyroid C. euthyroid D. mild hyperthyroidism E. severe hyperthyroidism |
Answer: Subacute thyroiditis (A)
Increased uptake in hyperthyroidism, iodine starvation, thyroiditis, hypoalbuminemia, lithium use. Decreased uptake in hypothyroidism, thyroid hormone therapy, Lugol’s solution, PTU, iodinated contrast agents, certain vitamin preparations, and thyroiditis. Subacute granulomatous thyroiditis (de Quervain’s ) and subacute lymphocytic thyroiditis both result in tranient hypothyroidism. Primer 627, 921 |
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A 40 y/o woman with a family history of thyroid disease has had a sore throat, neck pain, tremulousness, and restlessness for 4 weeks. Her T3 and T4 are both elevated. She undergoes I-123 scan 8 weeks after a contrast-enhanced CT study. Uptake is <1% after 4 hrs. She has:
a. Grave's disease b. Hashimoto thyroiditis c. Subacute thyroiditis (deQuervain thyroiditis) d. Acute suppurative thyroiditis e. triiodothyronine(T3) intoxication f. Multinodular goiter |
Answer: Subacute (DeQuervain) thyroiditis
Subacute thyroiditis (de Quervain’s disease) is a nonsuppurative granulomatous process that may affect all or part of the thyroid. Etiology thought to be viral. During the active phase, scintigraphy shows absent or decreased uptake in the affected part of the gland. Often patient has history of URI and neck tenderness. Thyroid tests elevated initially as the inflammation causes outpouring of stored hormone. Because both T3 and T4 are elevated and the study was performed beyond the 4-6 week post IV contrast window, Graves is out because the uptake is low. Hashimoto’s thyroiditis is usually chronic and slightly hypothyroid. |
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3 phase bone scan positive on all three phases in all of the following EXCEPT:
a. necrotic toe with peripheral vascular disease b. osteomyelitis c. osteoblastoma d. Charcot joint e. AVN in revascularization phase |
Answer: Necrotic toe with peripheral vascular disease (FALSE)
Osteomyelitis, osteoblastoma, Charcot joint and AVN in the revascularization phase all show positive 3 phase bone scan. |
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Regarding injection of FDG before PET scan, which is TRUE?
a. patient should rest quietly after FDG injection until performance of scan b. if hyperglycemia > 200, can inject regular insulin just before injection |
Answer: Patient should rest quietly after FDG injection
FDG is a glucose analog that is taken up by muscle and other organs that can lead to false negatives. Hyperglycemia is also known to cause a decrease of FDG uptake in malignant nodules due to competitive inhibition by high serum glucose concentrations. |
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Which is true about 18 FDG PET:
A Can do in hyperglycemic diabetics if they get SQ insulin just before administration B Give parenteral glucose a little before to reduce cardiac uptake C Patient should wait in quiet room 15-30 min after injection |
Answer: Can do in hyperglycemic diabetics if they get SQ insulin just before administration
It is okay to give insulin to a hyperglycemic patient prior to a PET. The reason for keeping blood sugar under control is to limit the competitive inhibition of FDG uptake with glucose. If it is a PET for malignancy the glucose needs to be under 200. The regulation for a cardiac study is more stringent. Ideally, the glucose for a cardiac study needs to be 120-140. The glucose cannot be too low because it promotes fatty acid metabolism and it cannot be too high because of competitive inhibition. |
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LEAST likely to have persistent increased uptake on MAG3 renal scan:
A Pyelonephritis B ATN C Obstruction D Renal artery stenosis E Renal vein thrombosis |
Answer: Pyelonephritis (LEAST likely)
Causes of poor excretion of tracer include medical renal disease (images should be correlated with patients' creatinine value), acute tubular necrosis, obstruction (one would expect to see associated hydronephrosis and likely have better parenchymal clearance of tracer, unless obstruction was quite high-grade), and dehydration. Dehydration can cause persistent parenchymal activity but a normal appearance collecting system. Patients should have vigorous oral hydration prior to nuclear renography. |
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LEAST likely to have persistent increased uptake on MAG3 renal scan:
A Pyelonephritis B ATN C Obstruction D Renal artery stenosis E Renal vein thrombosis |
Answer: Pyelonephritis (LEAST likely)
Causes of poor excretion of tracer include medical renal disease (images should be correlated with patients' creatinine value), acute tubular necrosis, obstruction (one would expect to see associated hydronephrosis and likely have better parenchymal clearance of tracer, unless obstruction was quite high-grade), and dehydration. Dehydration can cause persistent parenchymal activity but a normal appearance collecting system. Patients should have vigorous oral hydration prior to nuclear renography. |
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With radiochemical purity testing using chromatography, which is TRUE:
a. Free technetium migrates with acetone solvent front b. Free technetium migrates with saline front c. Technetium dioxide migrates with the solvent front |
b. Free technetium migrates with saline front
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PIOPED criteria for one large and one moderate V/Q mismatch:
a. intermediate b. high c. low |
Answer: Intermediate
High Probability (>80%): 1. Two or more large mismatched segmental defects. 2. Any combination of mismatched defects equivalent to the above (two moderate defects = one large defect). Intermediate probability (20–80%): 1. One moderate mismatched segmental defect with normal radiograph. 2. One large or two moderate mismatched segmental defects with normal radiograph. 3. Three moderate mismatched segmental defects with normal radiograph. 4. One large and one moderate mismatched segmental defect with normal radiograph. 5. Mismatched ventilation, perfusion and radiographic defects. 6. Difficult to categorize as high or low probability. Low Probability (<20%): 1. Nonsegmental perfusion defects. 2. Any perfusion defect with a substantially larger radiographic abnormality. 3. Matched ventilation and perfusion defects with normal chest radiograph. 4. Small subsegmental perfusion defects. Normal: 1. No perfusion defects. |
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FDG-PET is used for all of the following EXCEPT:
a. differentiation of glioma from brain abscess b. evaluation for recurrent colon cancer c. staging of lung cancer d. evaluation of solitary pulmonary nodule e. finding a seizure focus in epilepsy f. assessing myocardial viability |
Answer: Differentiation of glioma from brain abscess
PET is a poor way to differentiate malignancy from abscess. 18F-FDG PET and 18F-FET PET both have limited specificity in distinguishing between neoplastic and nonneoplastic ring-enhancing intracerebral lesions. Thus, histologic investigation of biopsy specimens remains mandatory to make this important differential diagnosis. |
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What is the greatest determinant of increased uptake of a bone scan in metastatic disease?
A Local blood flow B Increased osteolytic activity C Decreased as a sclerotic met widens |
local blood flow
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