GI Imaging Flashcards
1
Q
GI Imaging
Modalities
A
- X-Ray/ Radiograph
-
Fluoroscopic procedures
- Barium swallow
- Upper GI study / Small bowel follow through
- Contrast enema
- Ultrasound (US)
- Nuclear medicine/Meckel scan
- Computed tomography (CT)
-
Magnetic resonance imaging (MR)
- MR Enterography
2
Q
Abdominal XR
Overview
A
- Use beams of energy that pass through body tissues onto a special film
- Structures appear different based on XR absorption
- Air containing structures ⇒ black
- Bone and metal ⇒ white
- Easily available test
3
Q
Abdominal XR
Views
A
Can be obtained w/ pt:
- Supine view ⇒ lying flat w/ exposure from above
-
Erect/Upright view ⇒ standing up
- Can see fluid levels
- Stomach ⇒ always except if supine
- Small bowel ⇒ 2-3 levels possible
- Large bowel ⇒ none normally
- Can see fluid levels
-
Cross table lateral view ⇒ lying flat w/ exposure from the side
- Left side down
≥ 2 views ⇒ obstruction series
4
Q
Abdominal XR
Indications
A
Baseline study for eval of:
- GI sx such as vomiting, abdominal pain, distention, constipation, diarrhea, etc
-
Common GI disorders:
- Intestinal obstruction
- Constipation
- Appendicitis
- Colitis
- Inflammatory bowel disease
- Abdominal mass
- Pneumatosis/Pneumoperitoneum
- Foreign body ingestion
- Feeding tube placement
5
Q
Abdominal XR
Features
A
- Bowel gas pattern
- Free/Extra luminal air
- Soft tissue masses
- Calcifications
- Lung bases
- Osseous structures
6
Q
Abdominal XR
Normal Anatomy
A
- Solid organs ⇒ soft tissue density
- Air containing structures (stomach and bowel) ⇒ black
- Bone ⇒ white
-
Small bowel ⇒ central
- Contains valvulae which extend across the lumen
-
Large bowel ⇒ peripheral
- Has haustral markings
- Contains stool
7
Q
Normal
Bowel Gas Pattern
A
- Stomach bubble ⇒ LUQ
-
Small bowel
- Contains air throughout
- Normal caliber < 2.5 cm
-
Large bowel
- Air in rectum or sigmoid normally
- Air in the rectum mitigates against obstruction
8
Q
Abnormal
Bowel Gas Patterns
A
-
Functional ileus
- Localized ileus (Sentinel loops)
- Generalized adynamic ileus
-
Mechanical obstruction
- Small bowel obstruction (SBO)
- Large bowel obstruction (LBO)
9
Q
Localized Ileus
A
- Seen as sentinel loops on XR
- One or two persistently dilated loops of small or large bowel
- Gas in rectum or sigmoid
-
Location of sentinel loop is indicative of the underlying abnormality:
- RUQ ⇒ cholecystitis
- RLQ ⇒ appendicitis
- LUQ ⇒ pancreatitis or ulcer
- LLQ ⇒ diverticulitis
10
Q
Generalized Ileus
A
Term describes diffusely dilated small and large bowel
-
Ileus = stasis of bowel contents
- Paralytic or adynamic
- See gas in dilated small and large bowel to the rectum
- Common in the postop setting
- Bowel sounds absent or hypoactive
11
Q
Obstructive
Bowel Gas Pattern
A
-
Asymmetric caliber of bowel loops
- Loops proximal to obstruction ⇒ dilated
- See dilated loops of small bowel
- Loops distal to obstruction ⇒ compressed or airless
- Paucity of bowel gas distally
- Loops proximal to obstruction ⇒ dilated
12
Q
Pneumoperitoneum
A
Free intraperitoneal air
-
XR findings:
- Air beneath diaphragm
- Air outlined against liver/flank
- Multiple other signs possible
-
Causes
- Rupture of hollow viscus
- Not perforated appendicitis
- Ulcer
- Tumor
- Trauma
- Instrumentation
- Post-op (expected up to 5-7 days)
- Necrotizing enterocolitis (Neonatal setting)
- Rupture of hollow viscus
13
Q
GI Fluoroscopy
Overview
A
Provides dynamic assessment of the GI tract
-
Upper GI Tract
-
Barium swallow/Esophagram
- Upper GI tract coated w/ barium
- See & assess anatomy and function of esophagus, stomach, and duodenum
- Detect inflammation, hiatal hernias, scarring, blockages, intestinal malrotation and volvulus
- Upper GI study w/ or w/o small bowel follow through
-
Barium swallow/Esophagram
-
Lower GI Tract
-
Contrast Enema
- Water-soluble contrast introduced from below via a tube
- Helpful in evaluating colon for polyp, tumor, inflammatory bowel disease
-
Contrast Enema
14
Q
Barium Swallow
A
- Used to visualize the pharynx and esophagus
- Pt swallows liquid barium while XR images are obtained
- Can be used for:
- Dx of food impaction and esophageal FB
- Esophageal cancer
- GERD / hiatal hernia
Hiatal hernia shown in image on left. Esophageal reflux shown on right.
15
Q
Upper GI Study
A
- XR used to visualize stomach and small bowel
-
Duodenal sweep is assessed
- 1st, 2nd, 3rd and 4th components
- Normal location of duodeno-jejunal junction is left of spine @ level of duodenal bulb
Normal anatomy of stomach and proximal small bowel