Which of the following (organ or structure outline) can be visualized in the normal AP supine abdomen without obstruction of bowel gas or fecal material?
- stomach
- small intestines
- colon
- spleen
- liver
- gallbladder
- kidney
- pancreas
- psoas muscle
- ureter
- urinary bladder
- ovary
- uterus
Why is it necessary to include an upright or decubitus view when abnormal accumulations of intestinal gas is visualized?
because gas will rise deending on the postion of the pt
Describe the appearance of gaseous distention of the small versus large intestine
we normally see gas in the ST & LI – mb a little in the SI (mb concern for obstruction if > 3cm)
•recognize location by mucosal contour - there are more mucousal folds in the SI (when the mucousal folds of the SI are very close together – “stacked coin” appearance = small bowel obstruction)
What is a sentinel loop?
•(a loop of bowel) – an initial part of the SI that becomes atonic, becomes enlarged >3cm. warning! of an inflammatory process occurring
- Posterior displacement of the magenblasse is suggestive of enlargement of which organ?
(air bubble in ST fundus)
liver displaces it posteriorly
What is the normal orientation and position of the kidneys?
- retroperitoneal
- visible dt the presence of perirenal fat
- inf pole is more lat than sup
- Left (level fo T11-L2) Right (level of T12-L3)
- What is a phlebolith?
- venous calcification – stone w/in vein
- location & mvm’t may provide more practical info: masses may cause displacment
- dense, oval, well-defined; concentric or slightly eccentric interior lucency; AbN if midline
- Is plain film the best modality for diagnosis of an abdominal aortic aneurysm? If not, what is/are the best choice(s)?
Ultrasound is the imaging of choice in most cases 98%
•50-80% show calcification on x-ray •PR is 90% accurate
- Describe the appearance and location of pancreatic calcification. Give the most common cause
Numerous dense, discrete opacities that cross the midline at the level of L1-2 (conforms to the shape of the PN)
•note: remember the image of the calcifications (stipple like) that run fr the SP area over across the midline
- What is a dermoid cyst?
- aka – cystic teratoma: a congenital tumor, primarily ectodermal tissue
- MC ovarian tumor!!
- clinical presentation: tooth, BN, fat, rim of calcification may only be visible on CT
- Describe the appearance and location of a calcified uterine fibroma.
- aka Leiomyoma - MC tumor of the uterus
- these have lucencies within them and mb whirled in appearance
- may look like a LN when it is more lateral but, if seen along with others, esp if some in the uterine area it is probably fibroids
- Describe the appearance and usual location of prostate calculi.
•sharply defined homogenous concretions clustered in the region of the pubic symphysis
(may result fr TB or chronic pancreatitis)
What is an injection granuloma?
•an area of granulation that may form after injection
•solid mass calcifications
- Describe the appearance of residual contrast material in diverticulum.
???
- What is a staghorn calculus?
•a triple phosphate stone (80% calcify); homogenously dense sharpely outlined
pure uric acid stones are radiolucent
•growth of the calculi accommodate to the dimensions of the lumen of the renal pelvis & calyces
- Briefly describe the four different types of abdominal calcification patterns and common examples of each.
Concretions: calcified mass formed in the lumen of a vessel or hollow viscus; mulitple Laminations (layers of density), Circumfrential laminations (gall stones, appendicoliths), Homogenous (urinary calculi),
Examples: Phleboliths, prostatic concretioins, gallstones, staghorn calculi, fecliths, LV granulomas, PN concretions
Conduit Wall: calcification forms in the walls of hollow tubes; classically appear as parallel tracks of calcification (ATH plaques are not continuous); MC in the abdomen, aorta & its terminal branches
Examples: Aortic, common & Internal iliacs, splenic(serpentine appearance), renal (most dt atherosclerotic plaquing),vas deferens
Cystic: any calcium depostion in the wall of an AbN fluid filled mass; epithelial-lined true cysts, pseudocyst, spherical & ovaoid aneurysms;
• Crucial finidng for Cystic Patters: •smooth, curvilinear rim of opacity •rim need not be
complete •rarely laminated (note: remember pic of the AAA of L3,4,54)
Examples: AAA, common iliac, splenic artery, pocelain GB, Splenic cyst, Mesenteric or omental cysts
Solid Mass: Irregular border; complex inner architecture (mottled, whirled, amorphous); Psammamatous
Examples: MC is a LN!!!, bowel adenomas, hamartomas, TB or pyogenic abscess, Leiomyoma, adrenal gland calcification, nephrocalcinosis
- What is the percentage of radiolucent vs. radiopaque gallstones?
•aprx 30% calcify (radiopaque) – 70% we wont see on x-ray so order an US (70% radiolucent)
- What is a porcelain gallbladder and its significance?
•calcification of the GB wall (10-20% develop carcinoma of the GB)
- What is a hiatal hernia how may it appear on plain films?
- protrusion of a portion of the ST upward through the diaphram
- May look like gas on top of the ST (remember the image of the posterior mediastinal mass where we saw a hiatal hernia)
- diagnosis is made easy on plain films and mb an incidental finding on a chest radiogram
- What is the difference in appearance in a contrast (barium) study of polyp, ulcer and diverticulum?
•Polyp: intrinsic mass narrowing the lumen
•Ulcer: sometimes there is a small mound of assoc edema & others only the erosion is present. Ulcers have penetrated more deeply into the mucosa, they mb seen anywhere in the ST or proximal duodenum but are mc found in the antrum, pyloric canal, & duodenal bulb.
The mjr sx is the ulcer crater which usu projects beyond the gastric wall. There is often a smooth rim of edema at the edge of the crater. IF the ulcer has perforated free air mb seen under the diaphram on an upright film. Will heal with great deformity
•Diverticulum: evidence of an extrinsic mass narrowing the lumen is the mc observation, occ a sinus tract fr the colon
to the pericolonic mass will be seen, rarely a fistula to the BL or uterus cb demonstrated. The usu site is the sigmoid
colon but cb anywhere in the colon
- What is apple core deformity?
a mass involving / surrounding a tubular structure likethe esophagus, it makes an apple core appearance on x-rays when contrast fills the lumen
- What is lead pipe appearance?
- when the colon has lost its haustra appears straight as a lead pipe
- Assoc w/ UC
- Describe the appearance of the contrast within the collecting system of both kidneys during an IVP in a patient with obstruction from a kidney stone in one ureter.
- the MC place for a stone to lodge is where the ureter meets the BL, in the middle of the uretur where it is closest to BN & where the uretur leaves the KD
- each reanl pelvis gives off 2-4 mjr calyces which give of 6-14 minor calyces
- What is the percentage of radiolucent vs. radiopaque kidney stones?
•90% calcify (radiopaque)
