1 GI Diagnostics Flashcards
What different views can you order for abdominal xrays?
AP projection while patient supine
Upright
PA chest xray
When would you want an AP abdominal view xray?
Aka KUB (kidney ureter bladder)
Done while patient is supine
Upright abdominal xrays are better for …
Visualization of air-fluid levels
PA chest X-rays can be used to visualize…
Free air underneath hemidiaphragm and check chest pathology
Indications for abdominal xray
Abdominal pain, N/V, distention (can see on CT too but xray is faster, cheaper, less radiation)
Intestinal obstruction
Perforation (will see air in places it shouldn’t be)
Intussusception (peds usually)
Dilated bowel proximally with collapsed bowel distally indicates…
Obstruction
Will also see air fluid levels
Abdominal xray showing generalized dilated bowel and gas in both small and large intestines indicates…
Paralytic ileum (non-mechanical bowel obstruction) - frozen bowel, common after surgery, but NO clear obstruction
Abdominal xray shows free air outside the bowel. You suspect…
Perforation
Thickened and edematous bowel wall on xray is indicative of…
Small bowel obstruction
A loop of bowel slipped into another section of bowel, creating swelling, decreased blood flow, obstruction, and tissue damage
Intussusception
Requires emergency treatment
Risks/complications of abdominal xrays
Contraindicated in pregnancy
Radiation exposure
Use of reflected sound waves to visualize the abdominal aorta, liver, gallbladder, pancreas, bile ducts, spleen, kidneys, ureters, bladder
Abdominal ultrasound
Doppler US provides additional info re: blood flow
Can be ordered for specific location/organ
Dark areas on U/S are…
Hypoechoic
Examples: aorta, bile ducts, abscesses, cysts
White areas on U/S are …
Echogenic (solid)
Examples: tumors
When is an abdominal U/S indicated?
Abdominal pain
Elevated LFTs
Known/suspected liver disease
S/p kidney, pancreas, or liver transplant
Acute/chronic renal failure
What kind of abnormalities can you see on a liver u/s?
Cysts, abscesses, tumors, cirrhosis
Dilated bile ducts
What kind of abnormalities can you see on a gallbladder u/s?
Tumors, polyps, stones, sludge, inflammation (wall thickening)
What kind of abnormalities can you see on a pancreatic u/s?
Cysts, abscesses, tumors, inflammation
Risks/complications of U/S?
There aren’t really any - No contrast, no radiation
Useful study in patients with contraindications to other diagnostic tests
Computerized xrays that produce cross-sectional images of the body layer by layer
CT scan
Used to evaluate abdominal and pelvic organs
CT images can be enhanced with …
IV or PO iodine contrast
What is the exception to using contrast for abdominal CTs?
Renal stone study - because calcium stones are radiopaque, you won’t see them if you have contrast added
Indications for abdominal CT
Abdominal pain Abdominal distention N/V Diarrhea Constipation Rectal bleeding Jaundice
Can you use CT to diagnose cholecystitis or cholelithiasis?
You can but US is preferred over CT
What is the preferred test for evaluating the pancreas?
CT preferred over US for pancreatitis
Can also use CT to evaluate pancreatic cysts, abscesses, tumors, or calcification
US is preferred over CT for ________, but CT is preferred over US for __________
US for cholecystitis/cholelithiasis
CT for pancreatitis
If you do use CT to evaluate cholecystitis, what will you see?
Distended gallbladder with an edematous and hyperemic wall and inflammatory induration in the fat surrounding the gallbladder
Calcified stones can also be visualized on CT
Contraindications for abdominal CT
Pregnancy
Unstable vitals
Morbid obesity
IV contrast - allergy to iodine or SHELLFISH (in some cases, can premedicate)
Elevated creatinine
Complications of CT scans
Reaction to contrast (ranges from flush/itch —> anaphylaxis)
Acute renal failure from contrast
What precautions are important to remember with CT scans
Hold metformin for 48 hours post-contrast administration
Radiation risks - 1 abdominal CT = 250-500 CXRs (avoid unnecessary CTs)
What is a HIDA scan?
Hepatoiminodiacetic Acid Scan aka GB nuclear scan aka cholescintigraphy
Patient receives IV technetium labeled hepatic iminodiacetic acid —> taken up by liver and excreted in bile
Nuclear scanner tracks flow of tracer
If cystic duct is patent, tracer will go to GB, where it can be visualized
A HIDA scan is considered positive if…
Gallbladder does not visualize due to cystic duct obstruction in the setting of obstructing stone or edema
HIDA scans provide best information when ordered concurrently with…
CCK stimulation and ejection fraction (tests pumping ability of the gallbladder)
What is the primary indication for HIDA scans?
To diagnose suspected acalculous cholecystitis (though you would start with U/S)
What findings would you expect on a HIDA scan in the case of cholecystitis?
No radionuclide seen in gallbladder within 15-60 min
Ejection fraction <35%
Test reproduces patient’s symptoms
When is a HIDA scan contraindicated?
Pregnancy
If you want to do a HIDA scan, what do you need to remember to do?
DO NOT give pain meds!
Morphine will effect results
How is an Upper GI series performed?
Patient drinks barium sulfate contrast (or gastrografin) and fluoroscopy is used to visualize esophagus, stomach, and first part of the duodenum
Esophageal/barium swallow is a variation that shows throat and esophagus only
AKA esophageal, barium swallow
When is an upper GI indicated?
Dysphagia
GERD symptoms
Early satiety
Suspected PUD
Suspected obstruction/inflammation
Portion of stomach above diaphragm on UGI?
Hiatal hernia
What UGI findings suggest potential cancer?
Strictures, obstructions, filling defects, tumors, ulcerations
Filling defect = displacement of contrast medium by a space-occupying lesion in a radiographic study of a contrast-filled hollow viscous
Leakage of barium outside of UGI tract indicates…
Perforation
USE WATER-SOLUBLE GASTROGRAFIN
If you suspect perforation, UGI should be performed with…
Water soluble gastrografin rather than barium contrast
If you suspect a gastric ulcer, or see one on UGI, what else do you need to order?
EGD!!!!
Contraindications for UGI series
Pregnancy
Complete bowel obstruction
Suspected upper GI perforation (use gastrografin not barium!!!)
Unstable vital signs
Possible complications for UGI series
Aspiration (esp if dysphagia)
Constipation from the barium
Barium enemas are AKA…
Lower GI series
Patient receives a barium enema and fluoroscopy is used to visualize the colon and distal SB
Can be an alternative to colonoscopy
When would a barium enema be therapeutic?
To reduce a non-strangulated ileocolic intussusception
Contraindications for barium enemas
Pregnancy
MEGACOLON
Suspected perforation (must use GASTROGRAFIN)
Unstable vitals
Complications of barium enemas
Perforation
Fecal impaction due to barium
Direct visualization of the upper GI tract via a long, flexible, fiber optic lighted scope
EGD (esophagogastroduodenoscopy)
Performed under conscious sedation (not full anesthesia)
Can be both diagnostic and therapeutic
Indications for EGD
Alarm Sx (DYSPHAGIA, WEIGHT LOSS, EARLY SATIETY, EPIGASTRIC PAIN)******* N/V, abdominal pain Dyspepsia Chronic GERD Suspected esophageal varies Hematemesis or melena Fe deficiency anemia Abnormal UGI Suspected enteropathies (ie celiac) Foreign body/food bolus
Contraindications for EGD
Uncooperative patient
Bleeding
Esophageal diverticula (b/c inc risk of perforation)**
Suspected perforation (b/c can be worsened)**
Recent upper GI tract surgery (weak anastomoses site)**
Complications of EGD
Perforation
Bleeding from biopsy
Aspiration of gastric contents
Oversedation
What is an ERCP?
Endoscopic retrograde cholangiopancreatography
Involves use of fiber optic endoscope to obtain radiographic visualization of BILE AND PANCREATIC DUCTS
Similar to MRCP (Magnetic Resonance Cholangiopancreatography)
Indications for ERCP
Obstructive jaundice
Investigation/treatment of obstruction of bile and pancreatic ducts (mass, choledocholithiasis, cholangitis)
Therapeutic uses for ERCP
Can perform sphicterotomies, remove stones, place stents, and obtain brushings/biopsies
Incision in ampulla of vater to widen common bile duct and gallstones can be removed
Contraindications for ERCP
Uncooperative patient
Previous GI surgery with inaccessible ampulla of vater
Complications of ERCP
Pancreatitis Perforation Gram-negative bacteremia/sepsis (from translocation of bacteria into Biliary —> blood system) Aspiration of gastric contents Oversedation
Procedure that allows for direct visualization of the rectum, colon, and terminal ileum via a long, flexible, fiber optic-lighted scope
Colonoscopy
Usually performed with conscious sedation
Both diagnostic and therapeutic
Requires bowel prep
Procedure with visualization limited to rectum and sigmoid colon
Flexible sigmoidoscopy
Indications for colonoscopy
Colon cancer screen (remove polyps, biopsy)
Potential colon cancer symptoms (change in BMs, hematochezia, iron deficiency anemia)
SSx of IBD
Hematochezia
Diarrhea
Prior abnormal test (BE, CT)
Foreign body removal
Decrompression of volvulus
Contraindications for colonoscopy
Uncooperative patient Severe rectal bleeding Suspected perforation Recent colon surgery Toxic MEGACOLON Active diverticulitis or colitis
Complications of colonoscopy
Perforation
Bleeding
Oversedation
Non-invasive stool test with DNA markers and immunochemical test for hemoglobin in the stool
Cologuard
Alternative to colonoscopy for colon cancer screening
Frequency of testing not yet established (Q3years?)
