GI Radiology Flashcards
Generalization about imaging solid organs vs luminal GI tract
Luminal GI tract like the stomach and bowels use luminal contrast studies (i.e. esophagram, SBFT, etc).
Upper abdominal solid organs such as the liver, gallbladder, and pancreas use cross-sectional techniques (i.e. CT, US, MRI)
CXR
Identify free air in the abdomen
Must be an upright image
Abdominal XR
Indications:
- Evaluation of the stomach, small bowel, or colon
- Evaluation of air-fluid levels (ileus or obstruction)
- Free air
- Tube/catheter/drain position
- Abdominal calcifications
**Views: **
-
Flat/supine
- Can see bowel obstruction
- Distention
- Decubitus
-
Upright
- Extralumenal air can be visualized beneath the diaphragm
Recorded Video Swallow
Watch patient swallow different densities of radiolabeled food under fluoro (thick–> thin)
Performed with speech pathologist and radiologist
Indications: CVA, dysphagia, recurrent aspiration, neuromuscular diseases
Esophagram
Single Contrast:
- Large volume of low density barium
- Valuable in contour abnormalities, strictures, and large polypoid filling defects
Double Contrast/Air Contrast:
- High density barium coats mucosa, then swallow low density barium to produce see through images with greater mucosal detail
- Can better visualize early mucosal neoplastic or inflammatory lesions
Use Barium if evaluating lumen
Use gastrograffin if perforation is suspected
Upper GI
Same as esophagram: single or double contrast studies available
Indications
- Evaluate motility, contour, obstruction and abnormalities of the lumen
- Peptic ulcer disease
- Follow up on abnormal studies
- Post surgical
Prep: NPO for 8 hours
**Largely replaced by endoscopy
Small Bowel Follow Through
(SBFT)
Procedure:
- Pts drinks 2 cups thin barium
- Overhead AXR obtained at routine intervals until barium reaches the colon
- Transit time, mucosal contour, bowel loop distribution are evaluated
- Insensitive for small/subtle masses
Indications:
- Crohn’s Disease–fistulas
- Obscure GI bleeding
- Anemia
- Bowel obstruction (Gastrografin CI for obstruction)
Preparation: NPO after evening meal
Enteroclysis
Procedure:
- Double contrast small bowel series (SBFT)
- NGT placed at duodenal jejunal jtn through which barium is injected and bowel distentended
- Better visualization of small masses than normal SBFT
- Extremely uncomfortable for pt
Indications:
- Same for SBFT
- High index of suspicion or normal SBFT is inconclusive
Preparation:
- NPO after even meal and 2 tsp MOM the evening before the exam
Barium Enema
Can be single or double contrast
Indications:
- Bowel obstruction
- Suspected diverticulosis
- IBD
- F/u abnormal imaging studies
- Anemia
Prep:
- Clear liquids 24 hrs before exam
- Laxatives the evening before and day of exam
- Suppose the morning of the exam
- May be performed without prep in acute obstruction or to ID anatomy like malrotation
Take a post evac film to ensure barium is cleared
Gastrograffin Enema
Indications: evaluate bowel perforation
Therapeutic: obstipation
Contrast X-ray Risk
(RVS, Esophagram, UGI/SBFT, and BE)
Radiation exposure
Allergic rxn to contrast
Rarely: perforation, aspiration, barium retention
Abdominal CT (Contrast)
IV, oral, or rectal contrast
Oral and IV contrast preferred
Cannot give IV contrast in renal insufficiency–PO ok
PO contrast also okay to give in pts with IVP allergy
*Be cautious with IV dye
Abdominal CT Indications
Abdominal pain
Suspected inflammatory condition (appendicitis, diverticulitis, abscess)
Evaluation of tumors
Enlarged organs on exam or other imaging studies
Suspected obstruction
Tool to guide needle biopsy or aspiration
Abdominal CT Preparation
Non contrast: none
Oral contrast: NPO for 6 hours except oral contrast 2h, 1.5h, and 30min prior to exam
IV contrast: NPO for 6 hours
CT colography: clear liquids 48h prior to exam, complete polyethylene glycol prep and NPO 4h before exam
CT Colography
Does not require sedation
Requires same bowel prep as colonoscopy
Air used per rectum to distend colon
Quick examination
Images processed for 3D viewing and diagnosis
Not recommended for colorectal cancer screening
