Exam IV: Abdominal and Pelvic Imaging Flashcards
Kidney, Ureters and Bladder AP Supine X-ray (KUB)
Most basic x-ray evaluation of abdomen
No contrast given
You should look for: liver, spleen, kidneys, psoas shadows, intestinal gas pattern
Normal small bowel should be 2.5cm or less
2.5cm to 3cm is borderline
Larger than 3cm is dilated
Recognizing GI Structures by their Mucosal Folds
Stomach with rugae
Circular folds of small bowel mucosa
Haustral folds in colon
Narrow, circular folds represent small bowel
Wider, rounded haustrations show colonic involvement
Dilated Small Bowel
Multiple loops of dilated small bowel
Circular folds are clearly visible
Air Filled Colon
Note haustrations and tenia when colon fills with air
Colon can become massively dilated
KUB with Gallstones
Incidental finding
Only about 15% of gallstones are visible on x-ray
Ultrasound is the diagnostic test of choice when biliary pathology is suspected, not KUB
Not all gallstones require surgery
Porcelain Gallbladder
Gallbladder seen in right upper quadrant (RUQ) outlined by calcifications
Rare, premalignant condition in which the wall of the gallbladder becomes calcified
Risk factor for gallbladder cancer
Requires gallbladder removal because if gets cancer there is no cure and spreads so quickly
Absolute indication for cholecystectomy
Radio-Opaque Foreign Body
Will find swallowed coins, missing jewelry, bullets – any dense object
A KUB is also what we order when the surgeon can’t quite figure out where that last instrument has gone
Abdominal Series
Includes three separate X-ray films:
- AP supine abdomen (KUB)
- AP upright abdomen
- PA Chest X-ray
Decubitus position is used when patient cannot stand up
Left side down puts the large, smooth edge of the liver at the top of the image – if there is free air it will be seen there
Looks for:
Bowel dilatation (dilation)
Air-fluid levels in the abdomen
Free air beneath the diaphragm
Supine vs. Upright
Same patient
When supine, fluid forms a uniform layer, not visible
Standing the patient up shows air fluid levels
It is normal for the intestine to contain air and fluid but not in the same place
Contrast Studies
Upper GI series (UGI) or small bowel follow through use barium to coat mucosal surfaces and outline the lumen
Iodinated contrast is used instead of barium if perforation is suspected
Double-contrast UGI series (Enteroclysis) uses barium and air to coat the mucosa and distend the lumen
Upper GI Barium Study
Oral Barium or iodinated contrast
Dynamic flouroscopic examination
NPO overnight
No laxatives or other preparation needed
Includes stomach and duodenum to ligament of Treitz
Barium is visible in the proximal jejunum but it is not included in this study
Ligament of Treitz: filmy layer of tissue on the duodenum; distinguishes from an upper GI and lower GI bleed
Hiatal Hernia
Use Upper GI Barium Study to Dx
Herniation of part of the stomach through the diaphragmatic hiatus
Common - found in up to 20% of population
Two types:
1. Sliding type (most common 95%)
2. Para-esophageal
Both can cause reflux, have similar symptoms but different potential complications
Sliding Hiatal Hernia
Large portion of fundus “pulled up” into mediastinum, gastroesophageal (GE) junction has moved
Herniated portion of the stomach has entrance and exit
Only repaired if severely symptomatic
Paraesophageal Hiatal Hernia
Fundus of stomach has “flipped up” into mediastinum, GE junction has not moved
Fundus forms a pouch, only one opening
Susceptible to strangulation
Routinely repaired
Twisted stomach above the diaphragm can build up harmful bacteria, and if explodes is right next the heart so is very dangerous
Small Bowel Follow Through
Includes jejunum and ileum
May take up to 5 hours to get through the bowel
Difficult to read individual images without watching the study or reading the report
Roll the patient side to side so barium moves and get lots of information
Double Contrast or Enteroclysis
A tube is placed through the stomach, into the duodenum
Barium coats mucosa, add air to distend/inflate the bowel
Gives excellent detail
Not very comfortable for patient
Constriction of ileum, “apple core” lesion that goes in circular pattern; can be cancer and double contrast will allow you to dx this
Enteroclysis with Filling Defect
Large white mass is overlapping normal bowel
Only tells us that a mass is present on the bowel wall
May or may not be malignant
If no air injected with double contrast, would have missed this
Might not be seen on single contrast study or CT
Barium Enema
Single or double-contrast barium enemas require NPO overnight and colonic cleansing (5 liters of GoLytely®)
Barium enema looks for changes in diameter, intraluminal masses, colon polyps, diverticuli, colon cancer
Dynamic flouroscopic examination
Similar information obtained with colonoscopy
Barium is forced into rectum, all the way around to the cecum
Very dense, shows outline clearly
Patient can be rotated and tilted for different views
Does not show details of mucosa well
Structure of Transverse Colon
Large “apple core” lesion- highly suggestive of malignancy
The cecum receives mostly liquid through it, so the apple core wouldn’t give patient symptoms since it is just fluid going through; barium provided this finding or otherwise cancer would have developed
No proximal dilatation – may not have been symptomatic
Single Colon Polypon Barium Enema
Single pedunculated (“with stalk”) polyp in the sigmoid colon Seen as a filling defect within the barium column (minimal detail)