Ch.18 - Recognizing GI, Hepatic, and UT Abnormalities Flashcards
Radiologic findings of gastric ulcer:
- Persistent collection of barium that extends outward from the lumen beyond the normal contours of the stomach.
- Usually along the lesser curvature or posterior wall in the region of the body or antrum.
- May have radiating folds which extend to the ulcer margin and a surrounding margin of edema.
Key finding in gastric carcinoma:
Mass that protrudes into the lumen and produces a filling defect, displacing barium.
Gastric carcinomas may be associated with:
- Rigidity of the wall.
- Non distensibility of the lumen.
- Irregular ulceration or thickening of the gastric folds (>1cm).
- Especially localized to one area of the stomach.
Radiologic findings of duodenal ulcers include:
- Persistent collection of contrast.
- More often seen en face with surrounding spasm and edema.
- Healing of the duodenal ulcers produces scarring and deformity of the bulb.
Any imaging evaluation of the bowel should ideally be carried out with:
The bowel distended with air or contrast because collapsed and unopacified loops of bowel can introduce artifactual errors of diagnosis.
Key abnormal findings of bowel disease on CT:
- Thickening of the bowel wall.
- Submucosal edema or hemorrhage.
- Hazy infiltration of fat.
- Extraluminal air or contrast.
Imaging study of choice for diverticulitis:
CT.
CT findings of diverticulitis:
- Pericolonic inflammation.
- Thickening of the adjacent colonic wall (>4mm).
- Abscess formation and confined perforation of the colon.
Colonic polyps can be visualized with:
- Barium enema.
- CT virtual colonoscopy.
- Optical colonoscopy.
Imaging signs of colonic polyps:
- Persistent filling defect in the colon with or without a stalk.
- Some larger, villous adenomatous polyps have higher malignant potential and may contain barium within the interstices of their fronds.
Imaging findings of colonic carcinoma:
- Persistent, large, polypoid or annular constricting filling defect of the colon.
- May have frank or micro-perforation or large bowel obstruction and metastases, especially to the liver and the lungs.
Colitis of any etiology can cause:
- Thickening of the bowel wall.
- Narrowing of the lumen.
- Infiltration of the surrounding fat.
Study of choice in diagnosing appendicitis:
CT.
CT findings in appendicitis:
- A dilated appendix (>6mm) that does NOT fill with oral contrast.
- Periappendiceal inflammation.
- Increased enhancement of the wall of the appendix with IV contrast - sometimes identification of an appendicolith (fecolith).
CT findings in pancreatitis:
- Enlargement of the pancreas.
- Pancreatic stranding.
- Pancreatic necrosis.
- Pseudocyst formation.
Pancreatic adenocarcinoma:
Usually manifests as a focal hypodense mass - May be associated with dilation of the pancreatic and/or biliary ducts.
Fatty infiltration of the liver:
- Very common - can produce focal or diffuse areas of decreased attenuation that characteristically do NOT displace or obstruct the hepatic vessels.
- Liver appears less dense than the spleen.
In its later stages, cirrhosis produces:
- A small liver - especially the right lobe - with lobulated contour.
- Inhomogeneous appearance of the parenchyma.
- Prominent left + caudate lobes.
Evaluation of liver masses is frequently done utilizing a:
Triple-phase scan that includes:
- Precontrast scan.
- 2 Post contrast scans –> One in the hepatic-arterial phase and then another in the portal venous phase.
Metastases in the liver:
Multiple, low density masses that may necrose as they become larger.
HCC:
Usually solitary and typically enhance with IV contrast on CT.
Cavernous hemangiomas:
Characteristic centripetal pattern of enhancement and frequently retain contrast longer than the remainder of the liver.
Renal cysts:
- Very common.
- Frequently multiple and bilateral.
- Do NOT enhance - Sharp margins where they meet the normal renal parenchyma.
- On US –> Well-defined anechoic masses.
RCC - CT:
Usually a solid mass that enhances with IV contrast but remains less dense that the normal kidney.
RCC - US:
Frequently echogenic masses.
Imaging study of choice in evaluation of female pelvis:
US.
Esophageal diverticula occur in:
- Neck –> Zenker.
- Around the carina –> Traction.
- Just above the diaphragm –> Epiphrenic.
- -> Only Zenker tends to produce symptoms.
A single contrast study (also called full column) usually refers to …?
A GI imaging procedure in which only barium is used as the contrast agent.
A double contrast (sometimes called air contrast) usually refers to …?
A study of the GI tract using both thicker barium and air.
A biphasic examination is used to study …?
The upper GIT –> utilizes double contrast study followed by a single contrast agent to optimize the study.
What is a filling defect?
A lesion, usually of soft tissue density, that protrudes into the lumen and displaces the intraluminal contrast (eg a polyp is a filling defect).
What is the study of choice for diagnosing and documenting aspiration?
Video esophagography.
Fluoroscopic observation of the esophagus may reveal …?
Tertiary waves - Non specific abnormality of esophageal motility.
The 3 locations of the esophageal diverticula?
- Neck.
- Around the carina.
- Just above the diaphragm.
Diverticula at the level of the carina may be due to …?
Extrinsic inflammatory disease like TB (traction diverticula).
Epiphrenic diverticula?
Diverticula just above the esophagogastric junction.
What is frequently the initial study in patients with symptoms, like dysphagia?
Barium esophagograms.
Esophageal carcinomas may appear in one or more of several forms, including …?
- An annular-constricting lesion.
- Polypoid mass.
- A superficial infiltrating lesion or ulceration.
- Irregularity of the wall.
- -> Most often they present as a mixture of several of these patterns.
A Schatzki ring marks …?
The position of the EG junction so that its appearance ABOVE the diaphragm indicates the presence of a sliding hiatal hernia.
Double contrast UGI series have a sensitivity that exceeds …% in detecting duodenal ulcers.
90%.
Complications of duodenal ulcers are best demonstrated by …?
CT.
Orally administered contrast is routinely given for most abdominal CT scans. Exceptions:
- Those performed for trauma.
- The stone search study.
- Studies specifically directed towards evaluating vascular structures such as the aorta.
Oral contrast used for CT exam is either … or …?
Either a dilute solution containing barium or iodinated contrast.