GI radiology (words)

What are the nine parts of the abdomen?

What diseases can be found in each of the nine parts?

What are the indications for an abdominal XR?

-eval of bowel gas

-evaluation of pneumoperitonoeum

-assessment of radiopaque foreign bodies

-assessment of lines/tubes

-assess stool burden

What can we see in a Supine abdomen view XR?

-gas pattern

-calcification

-massess

What can we see in upright abdomen view XR?

-free air

-air-fluid levels (small bowel obstructions)

When do we use a CXR?

-pneumoperitoneum

-interthoracic conditions that can lead to referred abdomen pain

What views are included in acute abdominal series (AKA abdominal 3 view)?

-supine

-upright

-CXR

When do we use a left lateral decubitus view?

-pts who can't stand

-pneumoperitoneum

How can we use a left lateral decubitus view to identify pneumoperitoneum?

-free air will go to the highest part of the abdominal cavity (the pts right side)

-we will see the free air over the outside of the liver

What are limitations of an abdominal XR?

-hard to differentiate between structures of similar densities

-only 5 basic densities

-poor for disease diagnosis

What is a scout film?

-prelim image before imaging procedure to help position pt and locate areas of interest

How can we differentiate between small and large bowel?

How do valvulae appear on XR?

-stack of coins

-closely stacked and extend across the lumen of the small bowel

What do haustra look like on an XR?

-wide spread and do not traverse the whole diameter

Where does almost all gas in the bowel comes from?

-swallowed air

What is distention?

-normal

-loops of bowel that have sufficient amount of air to fill the lumen

What is dilation?

-abnormal

-loops of bowel filled beyond their normal size

What is a barium enema study?

-air and barium are both used as contrast agents

-allows for excellent visualization of the mucosal surface of the colon

What does stool look like on XR?

-multiple, small bubbles of gas within a semisolid appearing soft tissue

What does constipation look like on XR?

-soft tissue like opacitites with interla mottled air in the large bowel

What does hepatomegaly look like on XR?

-displacement of all bowel loops from RUQ down to the iliac crest and across the midline

What does splenomegaly look like on XR?

-projects below 12th rib

-displaces the stomach bubble toward or across the midline

What is a kidney intravenous pyelogram?

-pt given IV contrast

-we can see kidneys, ureters, and bladder

What are the 4 patterns of calcifications?

-rimlike

-linear

-lamellar

-cloudlike

What does nephrocalcinosis look like on XR?

-cloudlike calcifications within the kidney

What does a calcified gallbladder wall look like on XR?

-rim seen around the gallbladder

What are injection granulomas?

-multiple calcified lesions overlying and next to the ileum

-MC cause of calcifications in gluteal region

-IM injection--> fat necrosis and dystrophic calcifications-->visible granulomas

When do we use IV contrast?

-cancer

-trauma

-acute abdomen

-aortic aneurysm/dissection

When do we use PO contrast?

-non traumatic abdominal pain

-IBD

-abscess

-bowel perforation

-hernia

-bowel obstruction

When do we not use contrast?

-when we suspect a renal or ureteral stone

What is an abdominal aortic aneurysm (AAA)?

-enlargment of abdominal aorta

-Risk factors: HTN, atherosclerosis

-usually asymptomatic, but can cause pain

-large ones can rupture lead to hypotension and death

-get US to follow size, but if concerned about rupture GET CT

What is the risk of an AAA rupturing?

What is a calcified aortic aneurysm?

-common in those with DM

-aorta has rim like calcifications

-aneurysm is when normal diameter exceeds 50% of normal size

What is the difference between hyperecoic and hypecoic livers?

-hyperecoic: too bright=fatty liver

-hypecoic: starry sky=hepatitis

What does a normal pancreas look like?

-6 inches long and across the back of the abdomen, behind the stomach

-head is on the right and connected to doudenum

-tail is on the left side

What is the function of the pancreas?

-make digestive enzymes our body uses to break down and process food

-makes insulin

What do the kidneys look like on imaging?

-renal pelvis in the central portion

-right renal artery is posterior to IVC

-left renal vein in anterior to left renal artery

What does a normal bowel look like on imaging?

-less than 2.5cm

-wall is so thin it is almost invisible

-terminal ileum has fat containing "lips" of the ileocecal value which is outlines with contrast

What does a normal bladder look like on imaging?

-has unopacified urine

-bladder wall is thin and equal thickness around the circumference of the bladder

-rectum is posterior

What is Zenkers diverticulum?

-pouch that forms in the throat where the esophagus and throat meet

-caused by over tightening of cricopharyngeus muscle

-MC in older adults

What is cricopharyngeal achalasia?

-upper esophageal sphincter does not open adequately during swallowing leading to dysphagia

-Use barium swallow to evaluate

What is Barrett's esophagus?

-stratified squamous epithelium is replaced by simple columnar epithelium

-most people have GERD

-has risk in esophageal cancer

What is Achalasia?

-disease of lower esophageal body and sphincter

-sphincter fails to relax and open to let food pass

-caused by loss of inhibitory neurons in esophagus

-Sx: difficulty swallowing, chest pain, regurgitation

-complications: lung problems, loss of weight

-Dx: XR, endoscopy, esophageal manometry

What does achalsia look like on XR?

-birds beak

What is a sliding esophageal hernia?

-top part of the stomach pushes through the top part of the diaphragm

-GERD, heartburn, belching, nausea, chest pain

What is a paraesopahgeal hernia?

-stomach pushed up into the chest beside the esophagus

-incarceration: hernia stuck and squeezed

-strangulation: lack of blood supply

What are risk factors for hernia?

-pregnancy

-obesity

-family history

-increased age

What is a schatzki ring?

-thin, weblike filling defect just above the hernia

What is a small bowel obstruction?

-physical blockage in small intestine (adhesion, tumor, hernia)

-mostly due to adhesion

-Tx: NG tube

-Complications: sepsis, bowel ischemia, death

What is an ileum?

-functional, non mechanical obstruction where bowel muscle fails to contract properly

-due to nerve damage or med SE

-TX: NG tube

What is a localized ileus?

-from focal inflammation from adjacent organs

What is an adynamic ileus?

-post operative state

-electrolyte imbalance

-gas filled bowel distention, many bowel loops dilated

What are Localized ileus (sentinel loops) from pancreatitis?

-single, persistently dilated loop of small bowel in LUQ

What are the XR findings of an adynamic ileus?

-air filled loops of large + small bowels

-large and small bowel equally distented

-equal air fluid levels

-bowel can be distented

What are examples of mechanical small bowel obstruction?

-postsurgical adhesions

-tumor

-hernia

-gallstones

-intussusception

-IBD

What are examples of mechanical large bowel obstructions?

-tumor

-hernia

-volvulus

-diverticulitis

-intussusception

What are adhesions?

-band of scar tissue that cause internal organs and tissues to stick together

-MC in abdomen

-Cause by surgery, infection, and inflammatory conditions

What does SBO look like on an XR?

-step ladder appearance

What is a volvulus?

-when the ceum or sigmoid twists upon itself

-Coffee bean appearance

-considered a LBO

-massively dilated colon and haustra are absent

What is a sigmoid volvulus?

-when last part of large bowel twists on itself

-chronic constipation

What is pseudo-obstruction (Ogilvie syndrome)?

-in older hospitalized pt

-ascosiated with anticholinergic drugs

-loss of peristalsis

-TX: meds or bowel decompression

What are the 4 most common locations?

-intraperitoneal (free air): MC

-retroperitoneal air

-air in bowel wall (pneumatosis)

-air in biliary system (pneumobilia)

Etiologies of free air (pneumperitoneum)

-peptic ulcer disease

-bowel ischemia

-appendicitis

-colitis

-diverticulitis

-penetrating abdominal trauma

-foreign body ingestion

-endoscopic complications

-post surgery

What is pneumatosis intestinal?

-cluster of air containing cysts in the left colon

What is a rigler sign?

-double wall sign

-sign of pneumoperitoneum

-gas is outling both sides of the bowel wall

What is pneumobilia?

-air is present in biliarty system

-caused by abnormal connection between biliary tract and intestines

What is Crohns disease?

-skip lesions

-MC in terminal ileum

-affects all bowel wall layers (transmural inflammation)

What is ulcerative colitis?

-begins in rectum and spreads to colon

-long last inflammation and ulcers in digestive tract

-intermost lining only affected

-can lead to colon cancer

What is diverticulosis?

-outpouchings in the weakened colon walls

-MC in sigmoid colon

What is diverticulitis?

-one or more inflammed diverticula

-Sx: LLQ and fever

-complications: bowel obstruction, fistual, abscesses

-TX: Bowel rest, Abx, drainage, surgery

What are polyps?

-persistent filling defects in the colon

-barium is displaced by polyp

What is a virual colonoscopy?

-uses CT to contruct virual images of the colon

-Advantages: noninvasive, no sedation, can find polyps, can see outsisde of bowel

-Disadvantage: radiation, no biopsy available, have to inject air into colon, hard to see small or flat polyps

What is intussusception?

-part of the intestine folds into itself, blocking food and blood flow

What are risk factors for colorectal cancers?

-family history

-colon polyps

-long standing ulcerative colitis

what is the difference between left and right sided cancers?

-right: grow large before causing symptoms, cause iron deficiency=fatigue, weakness, SOB

-left: narrower part of colon so more likely to cause obstruction

Signs and symptoms of colon cancer include

-change in bowel habits

-bleeding/blood in stool

-persistant abdominal pain

-feeling that your bowel doesn't completely empty

-weakness, fatigue

-weight loss

What does colonic carcinoma look like on imaging?

-apple core lesion

What is colitis?

inflammation of the colon

-infectious

-ischemic

-IBD

What are the signs and symptoms of pseudomembranous colitis?

-diarrhea

-abdomainal cramps, pain, tenderness

-fever

-pus/mucus in stool

-nausa

-dehydration

What is appendicitis?

-inflammation caused by blockage of the appendix secondary to calcified stool or tumor of the cecum/appendix

-mid abdominal pain that migrates to RLQ (mcburneys point)

CT findings of appendicitis

->6mm

-enhancement and thickening of the wall

-infiltration of the fat

-appendicolith

-ascites

what is Pancreatitis?

-occurs when digestive enzymes produced in your pancreas become activated while inside the pancreas

-Sx: Upper abdominal pain, pain that radiates to your back, pain that is worse after eating, N/V, tenderness

-elevated amylase and lipase

What are the signs and symptoms of pancreatic cancer?

-normally occur in advanced disease

-upper abdominal pain, jaundice, loss of appetite, weight loss

-CT and MRI best

What is fatty liver?

-reversible

-caused by alcholism and obesity

-asymptomatic, can cause pain and enlarged liver

-MC cause of elevated LFT

What is cirrhosis?

-when healthy liver tissue is replaced with scar tissue

-MC Cause: hepatitis B and C, fatty liver, alcohol abuse

-complications: High bloop pressure in veins supplying liver, swelling in legs/abdomen, ascites, splenomegaly, bleeding from varices hepatic encephalopathy, jaundice, hepatocellular carcinoma

What is metastatic disease?

-MC malignant tumor of liver

-MC tumors that spread to liver: breast, colorectal, esophageal, lung, melanoma, pancreatic, stomach

-CT with IV contrast

What is hepatocellular carcinoma?

-primary malignancy of the liver (most pts have undering chronic liver disease and cirrhosis)

-Elevated AFT

-TX: chemo, radio frequency, surgery, chemo ablation

What are cysts?

-abnormal sacs filled with fluid in the liver

-can be present at birth, grow slowly

-most asymptomatic, large can cause bloating or RUQ pain

-most do not need Tx, large and painfully can be drained or removed

-associated with polycystic kidney disease

Cysts on imaging

-XR: well circumscribed, lobulated; black, good through transmission, no vascularity

-CT: round and well circumscribed, dark, do not enhance, no internal architecture

-MRI: T2 bright, well circumscribed, lobulated, T1 hypotense

What is hemangioma?

-noncancerous mass on liver

-no signs or symptoms normally

What is the best study for evaluating the gallbladder, except when its the distal common bile duct?

-US (pt should be fasting 608hrs)

What study is used to evaluate the distal common bile duct?

-MRCP

What is a gallstone/cholecystitis?

-made from cholesterol and bile substances

-4 F's (female, fat, forty, fertile)

-No symtpoms unless blocking cystic or common bile duct

-RUQ pain

What is a HIDA gallbladder scan?

-uses radioactive substances to take pics of the gallbladder, liver, and bile ducts

-shows blockages and infections

-Inject T99 choletect a radiotracer into the biliary tree (fills within 2 hrs)

-inject CCK and measure gall bladder contraction

-can look for bile leaks after surgery

What are risks for gallbladder cancer?

-MC in women, increases with age, obesity, prior gallstone, porcelain gallbladder, choledochal cysts, and chronic gallbladder infection