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63 Cards in this Set
- Front
- Back
What is the Photoelectric effect?
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The absorption of x-rays is directly proportional to the cube of the atomic number Z of the matter.
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What is the Compton effect?
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It depends on specific gravity (physical density) of the matter and is responsible for the majority of scattered radiation.
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The higher the specific gravity, the higher the atomic number which means the matter will show up as the color?
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White
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The degree of blackness of a radiograph is directly proportional to what?
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The number of x-rays that reach the film.
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What are some basic things to identify in radiographic interpretation?
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1. quality of film
2. positioning of animal 3. species 4. area under investigation 5. age, sex, breed/type, body condtion |
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What are Roentgen signs for pathological features?
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1. Size
2. Shape 3. Opacity 4. Position 5. Number 6. Margination |
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What does (RCd) stand for and give an example of when it would be used.
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Rostrocaudal view
Ex: skull for frontal sinus |
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What does (CrCd) stand for and given an example of when it would be used?
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Craniocaudal
Ex: shoulder |
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What does (ML) stand for and give an example of when it would be used?
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Mediolateral
Ex: shoulder or elbow |
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To examine the cardiac shadow, which radiographic technique would you use?
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Right lateral recumbency and DV view
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What radiographic technique is best for evaluation of the lung fields?
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VD view, except for caudal lobular lung vessels which are better on a DV
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Should radiographs be taken during inspiration or expiration?
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Full inspiration to ensure good contrast provided by air filled lungs.
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What does the mediastinum contain?
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trachea, oesophagus, the great vessels, and the heart, including pericardium, lymph nodes, lymphative vessels and neuronal structures.
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What is the normal cardiac shape and size in a dog?
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2.5-3.5 intercostal spaces wide and up to 2/3 the height of the thoracic cavity on lateral and 2/3 width of thoracic cavity of the DV/VD view
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What is the normal cardiac shape and size in a cat?
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<2.5 intercostal spaces wide and up to 2/3 the height of the thoracic cavity on lateral and 2/3 width of thoracic cavity of the DV/VD view
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What is important to note about the patient?
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Species & Breed --> because some are prone to certain disease
Age --> check if growth plates are open Body condition |
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Is the pleural space visible?
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No, only when thickened or fluid/gas is present.
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Describe pleural thickening.
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A fissure line is seen separating individual lung lobes and is an incidental finding in older dogs or secondary to pleuritis.
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What is pleural effusion?
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Is recognized as a soft tissue opacity, which causes retraction of the lung lobe margins away from the thoracic wall and highlights the interlobar fissures (fissure lines). Can cause collapse of lung lobes.
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How does a pneumomediastinum present radiographically?
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The air in the mediastinum causes outer margins of the tracheal and oesophageal walls to be visible. Can occur form tracheal or oesophageal injury or air tracking from the alveoli up the bronchial tree to the hilus.
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How does a Pneumothorax present radiographically?
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As free gas peripheral to the lung lobes which have increased opacity as a result of partial or complete atelectasis/collapse. Use VD or DV and a hot light to look for absence os vascular pattern.
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How does a megaoesophagus present radiographically?
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Gas filled esophagus.
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What can also accompany left sided cardiomegaly?
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Pulmonary venous congestion and oedmea
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What can also accompany right sided cardiomegaly?
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hepatomegaly, +/- vena caval enlargement and even pleural effusion and ascities.
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What views should be taken to evaluate the lungs?
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Both the right and left lateral views should be taken and either DV or Vd view is recommended.
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What are the four categories that roughly correspond to the structural components of the lung?
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1. Alveolar
2. Bronchial 3. Interstitial 4. Vascular 5. Mix |
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If the lung has alveoli that have been infiltrated by cells or fluid how will they look?
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Fluffy, ill defined areas of infiltrate, they highlight the air-filled bronchial structures producing "air bronchograms" which look like dark branching tapering stipes on a white background.
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What are some examples of diseases that cause alveolar pattern?
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Hypostasis/atelectasis, pneumonia, pulmonary oedema, haemorrhage
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The bronchial lung pattern looks like?
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Thickening of the bronchial walls produces a linear patter with the apperance of "tramlines" or "doughnuts"
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What causes a bronchial lung pattern?
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Bronchitis, "asthma" or bronchopneumonia.
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What does lung interstitial pattern look like?
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Diffuse --> sandy or grainy appearance of lung fields or a coarse, honeycombed appearance to nodular infiltrates. DOESNT produce air bronchograms (alveolar)
Nodular interstitial --> bronchiectasis |
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What does lung vascular pattern look like?
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The pulmonary vessels should be evaluated for increase or reduction in size, alteration in shape or loss of clarity of the margins.
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Preparing the patient for abdominal radiography involves?
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Starving for 12 hours prior
Possibly giving an enema to empty large intestine Contrast study involves starving patient for 24 hours. |
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To improve the contrast between the abdominal organs and the surrounding fatty tissue what kV and mAs should be used?
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Low to medium kV (60-80)
medium mAs |
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Should you take an abdominal film during inspiration or expiration?
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Expiration
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Abdominal organs should be evaluated using Roentgen signs which are?
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Size, Shape, Opacity, Location, Number, and Margination.
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Where are two common sites in older dogs and cats where intra-abdominal metastatic calicification is seen?
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In the kidney of older dogs forming radiopaque streaks similar looking to kidney stones.
In the adrenal glands of older cats causing no clinical significance. |
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Dystrophic calcification can be seen in?
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Damaged or necrotic tissue and is seen often in the wall of paraprostatic cysts or even in some neoplasia like adenocarcinom.
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What is the best view to assess a liver?
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lateral
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What are some causes for a small liver?
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Portosystemic shunt
Chronic liver disease |
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What are some causes for hepatic enlargement?
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Right sided heart failure
Fatty infiltrate secondary to various metabolic disease Neoplasia |
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What side of the abdomen is the spleen located on?
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The left between fundus of stomach and left kidney.
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What is the best view for assessing kidneys?
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VD
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Which kidney lies further cranially in the abdomen and can sometimes be hidden?
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The right kidney
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In which species (Dog or Cat) do the kidneys lie almost parallel to each other?
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The cat
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What causes small, irregularly marginated kidneys?
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Hypoplasia
Advanced chronic renal disease |
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What causes renal enlargement?
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Malignant lymphoma,
Acute nephritis FIP Hydronephrosis Hypertrophy secondary to portosystemic shunt |
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When a dog is lying on its left side the gas collects in what region?
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The pylorus
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When a dog is lying in right-sided recumbency the gas is seen in?
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the fundus
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Which species has a more V-shaped stomach with the pylorus lying in the midline?
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cat
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Psuedoulcerations can be seen in duodenum of young dogs, what is it?
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Focal accumulations of normal lymphoid tissue
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In the cat the duodenum can appear like a band of pearls, why?
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because of the distributed contraction waves along the duodenum.
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When does mineralization of the fetus take place?
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42-45 days after pregnancy in the bitch
36 days in the cat |
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During development the long bone consists of?
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2 epiphyses, 2 physes and 2 metaphyses and 1 diaphysis
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When can you detect radiographically if there has been bone destruction?
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when 50% of the mineral content has been lost.
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Benign lesions tend to progress more _______than aggressive malignant lesions.
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gradually
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How do aggressive bone lesions appear?
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moth-eaten or porous appearance with ill defined areas of cortical bone destruction.
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How does a less aggressive area of bone lysis appear?
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Smoothly marginated localized area of bone lysis
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What should you check when examining bones in radiograph?
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1. changes in size and shape
2. reduced bone opacity 3. increased bone opacity 4. cortical changes 5. changes to trabecular bone 6. endosteal new bone 7. periosteal new bone |
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Positive contrast media appears?
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more radiopaque (white)
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Negative contrast media appears?
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more radiolucent (black) like air or CO2.
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what are some examples of water soluble iodinated positvie contrast media?
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arthrography
gastrointestinal tract examinations myelography angiography |
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Magnetic Resonance Imaging (MRI) uses...?
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radio-waves and magnetic fields
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