GI Imaging MIDI Mod 2

Air fluid levels due to small bowel obstruction (SBO)

Intramural air because of necrotizing enterocolitis (NEC)

ABCDEs of reading abdominal radiograph

- Air in correct places

- Bones

- Calcifications

- Dilations

- Extraluminal free air/extra stuff

dilated loops of bowel

bowel filled with air or fluid beyond their normal size

in the small bowel, air is usually present in ___-____ loops on non-dilated small bowel. Normal diameter is <____cm

2-3, 2.5

in large bowel, there's almost always air in rectum/sigmoid colon. normal diameter is <____cm

6

3-6-9 rule for normal bowel diameter

- small bowel <3cm

- large bowel <6cm

- cecum <9cm

is a small or large bowel obstruction MC?

small bowel

valvulae connivente

thin, circumferential folds that extend across entire lumen of small bowel. Increased number in jejunum, appears like a stack of coins

haustral folds

thick, transverse, non-circumferential folds in large bowel with baggy appearance

____ bowel has 2-3 air/fluid levels present normally in upright/lateral decubitus view. _____ bowel has no or a few air/fluid levels present on upright XR

small, large

air fluid levels

caused by intestinal obstruction, prevents flow of fluids and gas, appears like a turtle shell

bowel dilation

caused by mechanical obstruction or impaired bowel motility, looks like a slinky

loops ____ to obstruction become dilated with air and fluid. Loops ____ to obstruction become decompressed as their contents are evacuated

proximal, distal

most dilated loop of GI obstruction

- ones with largest resting diameter (cecum)

- loops just proximal to obstruction

MC cause of colon obstruction?

masses (colon CA)

Potential etiologies of colon obstruction

- masses (colon CA)

- diverticular disease (narrowing or stricture)

- volvulus

- intraabdominal adhesions

types of bowel obstruction

- mechanical: physical blockage of colon (colon CA, diverticular dx, volvulus)

- non-mechanical/functional: due to lack of normal m contractions (paralytic ileus, intestinal pseudo-obstruction, narcotic-induced ileus)

dilated loops of bowel air fluid levels

dilated loops of bowel

small bowel obstruction usually starts in the ______

LUQ

causes of SBO

post-operative adhesions, malignancy, hernias, gallstone ileus, intussusception, IBD

string of pearls sign- diagnostic of mechanical obstruction

stretch sign- small pockets of gas trapped bn valvulae conniventes within fluid filled bowel

Large bowel obstruction

MC areas of LBO

cecum, hepatic/splenic flexures, sigmoid colon, upper portion of the rectum

T or F: signs and sxs of LBOs develop more slowly than SBOs

T

_____ valve determines the radiographic appearance of LBOs

ileocecal

competent ileocecal valve (closed loop)

gas and feces can't reflux into small bowel, pressure builds up only in colon

incompetent ileocecal valve (open loop)

gas and fluid reflux backward into small bowel

MC cause of LBO?

tumor

is perforation of a hollow viscus structure a medical emergency

yes

extraluminal air will rise to the highest part of the abdomen which is under the

diaphragm

crescentic lucency (extraluminal air)

types of extraluminal air

pneumoperitoneum, retroperitoneal free air, air in bowel wall, air in biliary system

pneumoperitoneum

retroperitoneal free air

air in bowel wall

air in biliary system

etiology of most calcifications can be determined by evaluatin

anatomic location, pattern of calcification

Lamellar "laminated" pattern

lamellar "laminated" pattern

amorphous "popcorn" calculi

porcelain gallbladder

abdominal CT

contrast used with bowel perforations

gastrografin

double contrast study

barium/gastrografin + air/gas

corkscrew esophagus- sign of diffuse esophageal spasm

Zenker's diverticulum

Esophageal narrowing

Hiatal hernia

manometric studies (manometry)

measures pressure at lower esophageal sphincter. Low pressure= GERD, high pressure= achalasia/DES

endoscopic evaluation allows for what 3 procedures

visualization, insufflation/aspiration, instrumentation

_____ endoscopy provides color video by way of a radiofrequency transmitter w/ several thousand images transmitted to a belt, worn by pt, over an 8 hour time period

capsule

Ulcerative colitis

apple core lesion- colon CA

diverticulosis

anoscopy

the visual examination of the anal canal and lower rectum

sigmoidoscopy

visual examination of the lower part of the colon (sigmoid)

proctoscopy

examination of the rectum and anus with a proctoscope

All patients >_____ years old should be screened for colon CA with colonoscopy

45

contraindications for colonoscopy

- anticoag or coagulopathic disease process

- suspected perforation

- toxic megacolon

- recent colon anastomosis

- recent acute diverticulitis

study of choice for abnormalities of biliary system

gallbladder US

gallstones

findings of acute cholecystitis

presence of gallstone (neck), thickening of gallbladder wall, fluid around gallbladder, positive murphy's sign

acute cholecystitis

hyperechoic shadowing of gallbladder walls (porcelain gallbladder)

Normal HIDA scan

postsurgical biliary leak (HIDA scan)

allows visualization of bile and/or pancreatic duct

ERCP

noninvasive method to image biliary tree without requiring the injection of contrast or dye

MRCP

T2 fluid filled structures appear _______ on magnetic resonance cholangiopancreatography (MRCP)

bright white

MRCP

radiographic visualization of bile ducts using XR and contrast, evaluates presence of obstruction or damage of bile ducts

cholangiogram

cholangiogram

3 different types of cholangiograms

- intraoperative cholangiogram

- postoperative cholangiogram

- percutaneous transhepatic cholangiography