Week 10: Gastrointestinal Pathologies Part 2 Flashcards
1
Q
Crohn’s Disease
A
- chronic inflammatory disorder of unknown cause most often in young adults
- usually in terminal ileum of small bowel and/or proximal portion of the colon (Crohn’s colitis)
- involves all layers of the GI tract
- may have healthy and diseased areas interspersed
- diffuse inflammation causes bowel loops to bind together
- ulceration is common, as well as fistulas to bowel and other organs
2
Q
Crohn’s Disease Radiographic Appearance
A
- barium studies are done
- irregular thickened and distorted mucosal folds
- string sign = narrowed stretch of bowel with no mucosal pattern
- skip lesion = diseased segments separated by healthy segments
- transverse and longitudinal ulceration produces cobblestone appearance
- CT also demonstrates thick mucosal walls
2
Q
Small Bowel Obstruction
A
- blockage of the small intestine
- due to adhesions from previous surgeries, peritonitis, hernias, intussusception, volvulus, tumours or vascular insufficiency
- may produce ischema with subsequent necrosis of bowel segment, sepsis and peritonitis
3
Q
Adynamic (Paralytic) Ileus
A
- fluid and gas (and any bowel contents) do not progress normally through a non-obstructed small (or large) bowel
- can be post op, peritonitis, medication, trauma
- part or all of small/large bowel fills to being peristalsis
- localized ileus = small part of small or large bowel affected
- colonic ileus = large bowel affected
- treatment: NG tube, IV fluids
3
Q
Inguinal Hernia Radiographic Appearance
A
protruding parts may be visible on imaging, not contained within abdominal cavity
3
Q
Small Bowel Obstruction Radiographic Appearance
A
- seen best on upright or decubitus abdomen
- air fluid levels will be seen
- loops of bowel will be distended/dilated proximal to the obstruction and collapsed distally
- small bowl loops may distend so much they look like large bowel
- may look like a step ladder or cascade
4
Q
Localized Ileus
A
- isolated distended loop (sentinel loop)
- due to adjacent inflammatory process
- radiographic appearance: one very distended loop
5
Q
Colonic Ileus
A
- excessive gaseous distention of bowel
- often see massive distention of cecum
- can look like mechanical obstruction (BE to rule out obstruction)
- radiographic appearance: retention of large amounts of gas and fluid in dilated small and large bowel with no demonstrate point of obstruction
5
Q
Inguinal Hernia
A
- some of the abdominal contents, usually part of the small bowel, protrude through a weak are in the abdominal wall at the inguinal canals (one on either side of groin)
- peritoneal sac bulges out too and surrounds the protruded contents
- the hernia may persist outside or slide in and out of the abdomen
- can cause constriction and/or ishcemia of protruding part
6
Q
Intussusception
A
- telescoping of one part of the intestinal tract into another because of peristalsis
- can compromise the vascular supply = ischemic necrosis of the intussuscepted bowel
- most common site in children: ileocecal valve
- major cause of bowel obstruction in children
7
Q
Intussusception Radiographic Appearance
A
- xray: coiled spring appearance on contrast enema
- CT: three concentric circles forming of soft tissue mass; target sign
- us: donut shaped lesion
8
Q
Hemangiomas - Benign Vascular Tumours
A
- occur anywhere along the GI tract, most often in the small bowel, then large bowel and rectum
- may cause bleeding
- radiographic appearance: contrast displacing mass on contrast study
9
Q
Diverticulum/Diverticulosis Radiographic Appearance
A
- multiple round or oval outpouchings from bowel
- thickened circular muscle may show sawtooth configuration
10
Q
Diverticulum/Diverticulosis
A
- diverticulum (single)/diverticula (plural) are out pouchings (herniations) of mucosa and submucosa through the muscular layers at points of weakness in the bowel wall
- lack of fibre and water in the digestive track can lead to development
- many diverticula = diverticulosis, may cause lower GI bleed
- diverticula can occur in esophagus or duodenum
10
Q
Polyps
A
- benign neoplasms that project into the lumen of the bowel
- mostly asymptomatic but certain types can become cancerous
- colonoscopy can find and remove
- found mostly in descending and sigmoid colon
11
Q
Diverticulitis
A
- complication of diverticular disease (diverticulosis), especially in the sigmoid region
- retained fecal matter trapped in diverticulum can lead to inflammation and perforation
- diverticulitis is inflammation of diverticula
- may produce peri-diverticula abscess
- may form fistula to adjacent organs
11
Q
Diverticulitis Radiographic Appearance
A
- similar to diverticulosis, barium study demonstrates round or oval out pouching projecting beyond lumen (usually multiple)
- contrast leaving from diverticula
- abscess soft tissue mass
- sawtooth configuration
- can cause narrowing and rigidity of long section of colon with gradual transition to normal
12
Q
Polyps Radiographic Appearance
A
- filling defect (barium enema)
- bulge flat against wall if sessile polyp
- stalk seen, polyp not flat against wall if pedunculated
12
Q
Sessile (Flat) Polyp
A
- irregular lobulated surface
- lie flat against colon wall
- more likely to be malignant
- inductive of cancer if over 2 cm in diameter, causes puckering/indentation/retraction at site or interval growth on subsequent exams
13
Q
Pedunculated Polyp
A
- smooth surface with a long thin stalk
- more likely to be benign
14
Q
Ulcerative Colitis
A
- an inflammatory bowel disease, often begins in rectosigmoid area
- may spread to involve entire colon, rarely involves small bowel
- usually involves only the mucosal layer of the colon
- alternating periods of remission and relapse
- can become cancerous
- symptoms: bloody diarrhea, abdominal pain, fever and weight loss
15
Q
Ulcerative Colitis Radiographic Appearance
A
- plain radiographs of BE
- granular mucosa
- large nodular protrusions, mucosal thickening = thumbprint sign
- deep mucosal ulceration = collar button appearance
- loss of haustral markings from muscular atrophy and spasm = classic lead pipe appearance
16
Q
Toxic Megacolon
A
- a complication of ulcerative colitis
- extreme dilation of part or all of large colon
- can lead to spontaneous bowel perforation
- due to perforation risk, BE contraindicated
- radiographic appearance: huge air filled colon
17
Q
Colorectal Cancer
A
- cancer of the colon and rectum, usually in the rectum and sigmoid
- peak age 50-70
- needs early diagnosis for best outcome
- several type
- can cause polypoid mass or surround colon
- ulceration common
- may have multiple carcinomas or metachronous cancer
- can metastasize
18
Q
Colorectal Cancer Radiographic Appearance
A
narrowed section of lumen with irregular contours, and rigid and tapered margins
19
Q
Annular Colorectal Carcinoma
A
- annual lesions surround the bowel from outside
- most common bowel cancer
- starts from flat plaques of tumours (saddle lesions), easily missed of exams
- usually in sigmoid
- radiographic appearance: BE will demonstrate apple-core or napkin ring filling defect
20
Q
Large Bowel Obstruction
A
- blockage of large bowel usually due to primary colon cancer
- could be from diverticulitis or volvulus
- less sever than small bowel obstruction
- form more slowly with fewer fluid and electrolyte disturbances
- causes increased pressure (closed loop) and risk of perforation, especially of cecum
21
Q
Large Bowel Obstruction Radiographic Appearance
A
- if ileocecal valve working: dilated colon with thin walled distended cecum and little small bowel gas
- if ileocecal valve not working: distended gas filled loops in small and large bowel
- gas with abrupt stop seen on abdominal xray
- CT recommended
22
Q
Volvulus Radiographic Appearance
A
- BE can confirm
- cecum volvulus: distended and displaced cecum in kidney shaped mass
- sigmoid volvulus: distended rectum with lumen tapering towards volvulus area (bird’s beak sign)
22
Q
Volvulus
A
- twisting of the bowel on itself that may lead to abdominal obstruction
- most frequently involves the cecum and sigmoid colon
23
Q
Malrotation Of Bowel/Colon
A
- twisting of the bowels, like volvulus bit occurs during fetal development
- may be problematic or not, depending upon severity
- volvulus symptoms may be first sign of malrotation: abdominal distention, pain, vomiting, constipation, bloody stools
- radiographic appearance: abnormal location of bowel on image
24
Q
Imperforate Anus (Anal Atresia)
A
- congenital lack of anal opening
- often associated with a distended bowel
- radiographic appearance: multiple dilated bowel loops filled with gas, absence of rectal gas
