Term
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Definition
| an intravenous radiographic contrast studying evaluating the vascular system |
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Definition
| a radiographic contrast technique evaluating the articular cartilage, joint space, and joint capsule |
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Definition
| a method of urethrography in which the contrast medium is voided from the urinary bladder |
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Definition
| a common positive-contrast medium that is avail in different forms and is often used as a suspension in GI evals |
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Definition
| an oral or IV rad contrast study eval the bile ducts and gallbladder |
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Term
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Definition
| a substance that is either radiolucent or radiopaque and can be admin to increase rad contrast w/in an organ or system |
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Definition
| radiographic contrast studies eval the urinary bladder |
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Term
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Definition
– a rad contrast tech that uses a combo of positive and negative contrast media simultaneously
ix. esophagography |
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Term
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Definition
| a rad contrast study performed to eval esophageal fxn and morphology |
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Term
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Definition
| an abnormal tubelike passage w/in body tissue |
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Definition
| a rad contrast study performed to eval the size, shape, position and morphology of the stomach |
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Term
| intravenous pyelogram (IVP) |
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Definition
| a rad contrast study of the kidney structure and collection system |
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Term
| intravenous urogram (IVU) |
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Definition
| a rad contrast study of the kidney structure and collection system |
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Term
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Definition
| commonly referred to as a barium enema; a rad contrast study eval the rectum, colon and cecum |
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Definition
| a rad contrast study eval lymphatic vessels and lymph nodes |
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Term
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Definition
| – a rad contrast study eval the subarachnoid space surrounding the spinal cord |
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Term
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Definition
gases that are more radiolucent to xrays than are soft tissues and have a black appearance on a rad
(ex: O2, CO2) |
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Term
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Definition
| substances containing elements of high atomic number that are more radiopaque to xrays than are tissue and bone and have a white appearance on a rad (ex: barium and iodine compounds) |
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Term
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Definition
| a negative-contrast rad tech evaluating the urinary bladder |
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Term
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Definition
| – a neg contrast rad study consisting of an intro of a gas into the peritoneal cavity |
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Term
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Definition
| – a phase of an excretory urogram characterized by the pacification of the renal collection method |
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Term
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Definition
| a rad contrast study eval the stomach and sm intestines |
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Term
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Definition
| a rad contrast study evaluating the urethra |
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Term
| T or F Barium sulfate is indicated if an upper gastrointestinal perforation is suspected |
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Definition
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Term
| T or F All iodine agents have local irritant effects and are contraindicated for myelography and orthography |
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Definition
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Term
| 4. T or F Using carbon dioxide as a negative control agent can cause an air emboli |
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Definition
| FALSE – using room air as a negative control agent can cause an air emboli, CO2 is absorbed by the body and safer to use |
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Term
| What is the disadvantage of using low-osmolar contrast media? |
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Definition
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Term
| Which positive contrast medium is completely insoluble in the gastrointestinal tract and is not absorbed by the abdomen or thorax if leakage occurs? |
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Definition
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Term
| T or F All patients who will receive a gastrointestinal contrast study must receive an enema |
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Definition
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Term
| T or F General anesthesia and atropine are contraindicated for gastrointestinal contrast studies because of the degree that they alter gastrointestinal morbidity |
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Definition
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Term
| T or F If an enema is administered, the contrast radiograph should not be taken until at least one hour post-administration. |
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Definition
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Term
| What is a suitable agent to use as an enema before performing a lower gastrointestinal study? |
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Definition
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Term
| What is the safest combination of agents to use for a cystogram? |
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Definition
| Triiodinated ionic compounds and carbon dioxide |
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Term
| What additional view can be helpful for assessing a positive contrast cystogram, especially in a male patient? |
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Definition
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Term
| Compare the differences between positive and negative contrast. |
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Definition
Positive contrast
- contain high atomic number elements
- these agents absorb more xrays than do soft tissues or bones
- radiopaque to xrays and appear white on a rad
- can be used to fill or outline a hollow organ *ex: urinary bladder, alimentary tract)
- can be injected into a blood vessel (sterile, water-based compounds only) for immed visualization of the vascular supply or for subsequent excretion evaluation
- ex: barium sulfate or iodine compounds
Negative Contrast
- consists of gases that have a low specific gravity
- substances w/ low specific gravity are more radiolucent to xrays than are soft tissues and have a black appearance on a radiograph
- ex: O2, CO2 |
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Term
| List a primary disadvantage in using barium sulfate for a GI study. |
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Definition
- if it should pass through a perforation in the alimentary tract into the thorax or abdo, it would not be absorbed or eliminated
- barium can remain in the body indefinitely and could potentially produce a granulomatous rxn
- if perforation is suspected, advisable to use a water-soluble contrast medium |
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Term
| List the different gases used for negative contrast studies. |
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Definition
- air, oxygen, nitrogen, nitrous oxide, carbon dioxide
- most commonly used – air, O2, CO2
- CO2 advantage over room air because better absorbed into the body when admin into a hollow organ; room air can cause air emboli |
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Term
| Explain patient preparation for a GI study |
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Definition
Upper GI Study
- fast for 12 – 24 hrs
- enema if needed 2 – 4 hrs before study
- sedate if necessary
Lower GI Study
- low-residue diet 48 hrs before study’
- fast for 24 hrs before study
- enema until clear, 12 hrs prior
- mild oral cathartic is needed
- anesthesia if needed |
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Term
| Why is an esophagography performed? |
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Definition
- to evaluate esophageal fxn and morphology
- indicated for pts w/ a hx of regurgitation of undigested food, acute gagging, or dysphagia |
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Term
| Name a precaution when administering oral contrast mediums |
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Definition
| - care must be taken to minimize the possibility of aspirating the agent onto the lungs |
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Term
| Why is an upper GI study performed? |
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Definition
- to eval the stomach and small intestines
- may be indicated for pts that have recurrent unresponsive vomiting, abnormal bowel movements, suspected FB or obstruction, chronic wt loss or persistent abdo pain |
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Term
| Explain the upper GI study process |
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Definition
- survey rads
- admin barium to distend the stomach with contrast medium (4 – 8 ml/kg)
- DV, VD, RLat, LLat immed after admin
- RLat, VD or DV at intervals until contrast agent reaches lg bowel (ex: 15, 30, 60, and 90 min) |
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Term
| What is a contraindication in using barium sulfate? |
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Definition
| suspected gastroenteric perforation |
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Term
| Why is a gastrography performed? |
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Definition
- eval the size, shape, position and morphology of the stomach
- indicated is pt is experiencing acute or chronic vomiting, blood in vomitus, or cranial abdo pain |
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Term
| List 3 studies that can be used for lower GI diagnostics. |
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Definition
| - positive- , negative- , and double-contrast studies |
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Term
| Explain the lower GI study procedure. |
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Definition
- survey rads, ensure lg bowel clear of all fecal matter
- pt lat recum, insert lubed catheter tip into rectum and inflate balloon just inside internal anal sphincter
- attach cather end to infusion device (bucket or bag) and syringe
- slowly infuse contrast medium (+contrast media should be warmed to body temp, dose is approx. 10 – 15 ml/kg)
- clamp catheter with clamp or hemostat
- leave catheter in place, expose lateral rad to eval distension of lg bowel
- add more medium if needed
- when desired distension of bowel reached, expose VD, R Lat, L Lat (oblique also if needed)
- after study completed, evacuate the contrast agent from the lg bowel as completely as possible by lowering the contrast reservoir below the pt level and allowing gravity to empty the agent from the bowel |
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Term
| Why are contrast studies performed on the urinary system? |
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Definition
- eval of kidneys, ureters, bladder, and urethra
- indicated for a pt w/ hematuria, proteinuria, crystalluria, polyuria, isothenuria, or dysuria |
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Term
| The excretory urography is also referred to what? |
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Definition
| an intravenous urogram (IVU) or an intravenous pyelogram (IVP) |
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Term
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Definition
- evaluates kidney structure and collection system
- is not used to evaluate renal fxn quantitatively |
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Term
| List and describe the two phases of the excretory urogram. |
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Definition
- nephrogram and pyelogram
- rads taken immed after the inj of contrast medium exhibit the agent uniformly perfused throughout the renal vasculature
- the diffuse oacification of the renal parenchyma is characteristic of the nephrogram phase
- this phase demonstrates the vascular supply and perfusion of the kidney and documents the presence of functional renal tissue, particularly if it persists beyond the angiographic blush
- pyelogram phase – as the contrast agent is filtered into the renal collection system w/ the urine, the renal pelvis and recesses are opacified
- can be accentuated by placing abdo compression on the caudal abdo uw/ a compression band or abdo pressure wrap, resulting in cessation of urine flow to the bladder – this is NOT needed or recommended because it can cause transient worsening of renal fxn |
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Term
| What is a precaution before injecting contrast medium for an excretory urogram study? |
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Definition
- any urine samples should be obtained before injecting contrast medium
- iodinated contrast agents increase urine-specific gravity ro a variable degree and induce a false-positive rxn for protein detected by sulfosalicylic acid |
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Term
| List some reasons a cystography is indicated. |
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Definition
| - unresponsive clinical signs such as hematuria, crystalluria, bacturia, dysuria, anuria, and incontinence |
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Term
| What 2 mediums are contraindicated for a cystography and why? |
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Definition
- barium sufate and sodium iodide
- although they are rare, complications w/ barium sulfate incl barium casts and interstitial fibrosis secondary to vesicouretal reflex
- barium also serves as a nidus for the formation of uroliths
- also, granulomatous dz may occur secondary to a rupture of the bladder or urethra
- sodium iodide soln is not recc because of its irritating effect on the mucosa of bladder/urethra
- known to produce acute hemorrhagic cystitis, epithelial ulcerations, and submucosal hemorrhage |
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Term
| Why is sedation recommended for an urethrogram? |
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Definition
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Term
| Why is an arthrography indicated? |
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Definition
- pt that is lame or has pain assoc w/ a joint, when survey rads are insufficient
- can be used to eval a ruptured joint capsule, the presence of a cartilaginous flap, meniscal injuries, or the need for surgery |
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Term
| Why is an angiography indicated? |
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Definition
| - may be used to demonstrate occlusion of a particular blood vessel, to demonstrate pathologic lesions of the vascular system, or to provide evidence of a tumor that was undefinable on survey radiographs |
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Term
| Describe a fistula and what is it a result of? |
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Definition
- any abnormal, tubelike passage w/in the body tissue
- usually the result of an injury of congenital deformity
- the presence of a draining wound of indetermined origin may indicate a fistulous tract and the need for a fistulogram
- often the site of the wound is far removed from the site of the drainage |
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Term
| Why is a myelography indicated? |
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Definition
| - to highlight a lesion that is undetectable on survey rads |
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Term
| Why is sedation indicated for a myelography study? |
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Definition
| - gen anes needed because of the sensitive nature of a subarachnoid inj |
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Term
| What are some disadvantages of using contrast agents when performing a myelography study? |
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Definition
- because of the extreme sensitivity of spinal tissues and the irritating effects of conventional ionic contrast agents, some pts suffered convulsion and death
- oily iodinated contrast agents have been used but don’t mix well with spinal fluid, tend to coagulate and have very slow absorption time
- currently a low-osmolar, nonionic, water soluble contrast medium is the standard choice |
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Term
| Why is a pneumoperitoneography indicated? |
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Definition
| - eval of the liver, spleen, stomach, distal colon, kidneys, urinary bladder, uterus, and abdo wall |
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Term
| What is a pneumocystogram? |
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Definition
| - a negative-contrast rad technique evaluating the urinary bladder |
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Term
| What is thermography used for in horses? |
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Definition
- can be used to examine specific body parts or used for whole body screens as part of regular “wellness” examinations of the legs.
- The primary use of thermography is to locate “hot spots,” which may indicate inflammation
- Heat is one of the cardinal signs of inflammation. Thermography is best used to locate inflammation near the body surface. Areas of inflammation deep within the thorax or abdomen cannot be seen with thermography. |
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Term
| Describe nuclear scintigraphy. |
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Definition
- a method of imaging that emphasizes physiology rather than anatomy. Whereas a radiograph or ultrasound takes an image of a patient's anatomy, scintigraphy takes an image of a patient's physiological processes.
- This is accomplished by administering a radioactive compound, allowing the compound to accumulate within the patient, and then measuring the amount of radioactivity emitted from the patient.
- A gamma camera is used to measure the radioactivity. |
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Term
| What is nuclear scintigraphy used for? |
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Definition
- helpful in detecting lesions when radiography and ultrasonography have not confirmed a diagnosis or cannot penetrate deeply enough, especially in the regions of the upper limbs, shoulders, and pelvis.
- Scintigraphy can also screen large areas of the patient |
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Term
| Why is it important to remove bandages and blankets before using thermography. |
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Definition
| Bandages, tack, and blankets can all cause a local increase in heat; patients should have these removed 2 hours before the examination. |
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Term
| Does the animal need to be under anesthesia to have a CT performed? |
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Definition
| - yes, gen anes to prevent motion during the scan |
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