Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Gastrointestinal Imaging (Beri) > Colon (PBR 2) > Flashcards

Colon (PBR 2) Flashcards

1
Q

A term that is generic for a lesion that protrudes from the mucosal surface of the GI tract

A

Polyp

The term does not imply a histologic diagnosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

This refers to radiolucency in a contrast media pool caused by a protruding mass lesion

A

Filling defects

On CT and barium enema examinations, filling defects maybe polyps, tumors, plaques, air bubbles, feces, mucus, or foreign objects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

“Bowler hats”

A

Polyps

*Creator’s notes
Remember BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Most common malignancy of the GI tract

Fourth most common malignant tumor

A

Colorectal adenocarcinoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Frequent or common locations of colorectal adenocarcinoma

A

Rectum and rectosigmoid area (50%)
Sigmoid colon (25%)
Remaining are evenly distributed throughout the remainder of the colon (25%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Morphologic patterns of colorectal adenocarcinoma

A

Annular constricting lesion
(most common - 2 to 6 cm in diameter, with raised everted edges and ulcerated mucosa)

Polypoid tumor
(less common, some having the frond-like appearance of villous carcinoma)

Infiltrating scirrhous tumor
(common in gastric carcinoma, are rare in the large intestine, unless the patient has ulcerative colitis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Most frequent/common complication of colorectal adenocarcinoma?

A

Obstruction

Other complications: 
Perforation
Intussusception
Abscess
Fistula formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Diseases that are at increased risk of colon carcinoma

A

Ulcerative colitis
Crohn disease
Familial adenomatous polyposis syndrome
Peutz–Jeghers syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Local staging of colorectal adenocarcinoma is best evaluated by what imaging method?

A

Transrectal or colonocopic US

CT and MR are used for more advanced disease and to detect recurrence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Cross-sectional imaging findings of colorectal adenocarcinoma

A
  1. Polypoid primary tumor (usually >1 cm)
  2. “apple core” lesions with bulky, irregular thickening of the colon wall and irregular narrowing of the lumen 3. Cystic, necrotic, and hemorrhagic areas within the tumor mass, especially when the tumor is large
  3. Linear soft tissue stranding into the pericolonic fat often indicative of tumor extension through the bowel wall
  4. Enlarged regional lymph nodes (>1 cm) representing lymphatic spread of tumor
  5. Distant metastases, especially in the liver
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Common locations of tumor recurrences

A
  1. At the operative site, near the bowel anastomosis
  2. In lymph nodes that drain the operative site
  3. In the peritoneal cavity
  4. In the liver and distant organs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The majority of colorectal cancers are believed to arise from pre-existing adenomatous polyps, the detection of colon polyps is a major indication for colonoscopy and imaging studies of the colon

What is the rule of “rule of thumb” in adenomatous polyps?

A

Polyps less than 5 mm are almost all hyperplastic, with a risk of malignancy less than 0.5%

Polyps 5 to 10 mm size are 90% adenomas, with a risk of malignancy of 1%

Polyps 10 to 20 mm in size are usually adenomas, with a risk of malignancy of 10%

Polyps larger than 20 mm are 50% malignant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

These polyps are nonneoplastic mucosal proliferations

They are round and sessile

Nearly all are less than 5 mm in size

A

Hyperplastic polyps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

These polyps are distinctly premalignant and a major risk for development of colorectal carcinoma

A

Adenomatous polyps

Approximately 5% to 10% of the population older than 40 years have adenomatous polyps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

These polyps represent 1% of colon polyps

They are a common cause of rectal bleeding in children

These polyps are seen in Peutz–Jeghers syndrome

A

Hamartomas polyps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Polyps that are usually multiple and associated with inflammatory bowel disease

They account for less than 0.5% of colorectal polyps

A

Inflammatory polyps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Polyposis syndrome in which colorectal cancer will eventually develop in nearly all patients

The inheritance pattern is autosomal dominant with high penetrance

A

Familial adenomatous polyposis syndrome

Polyps typically carpet the entire colon

Patients are at risk for numerous extracolonic manifestations including carcinomas of the small bowel, thyroid carcinoma, and mesenteric fibromatosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Patients with associated bone and skin abnormalities including cortical thickening of the ribs and long bones, osteomas of the skull, supernumerary teeth, exostoses of the mandible, and dermal fibromas, desmoids, and epidermal inclusion cysts have been diagnosed as what syndrome?

A

Gardner syndrome

Those with associated tumors of the central nervous system have been grouped as Turcot syndrome

These are variations of the same disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Diseases that cause hamartomatous polyposis syndrome

A

Peutz-Jeghers syndrome
Cowden disease
Cronkhite-Canada syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Dark pigmented spots on the skin and mucous membranes are characteristic of what hamartomatous polyposis syndrome?

A

Peutz-Jeghers syndrome

Risk of carcinoma arising from coexisting adenomatous polyps is 2% to 20%

Patients are also at risk for breast cancer, uterine and ovarian cancer, and early age cancer of the pancreas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

This is a syndrome of multiple hamartomas including hamartomatous polyposis of the GI tract, with goiter and thyroid adenomas and increased risk of breast cancer and transitional cell carcinoma of the urinary tract

The syndrome is autosomal dominant and affects mainly Caucasians

A

Cowden disease

All patients have mucocutaneous lesions with facial papules, oral papillomas, and palmoplantar keratoses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

A hamartomatous polyposis syndrome

This is a disease of older patients with a mean age of onset of 60 years

Polyps are distributed throughout the stomach, small bowel, and colon

Associated skin findings include nail atrophy, brownish skin pigmentation, and alopecia

Patients present with watery diarrhea and protein-losing enteropathy

A

Cronkhite-Canada syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Lymphoid hyperplasia may involve the colon

The normal lymphoid follicular pattern of diffuse tiny nodules 1 to 3 mm in diameter with characteristic umbilication is most common where?

A

In the terminal ileum and cecum but may involve any portion of the colon

The nodular lymphoid hyperplasia pattern of diffuse nodules larger than 4 mm is associated with allergic, infectious, and inflammatory disorders

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Most lymphomas of the colon are what of what type?

A

Non-Hodgkin B-cell lymphoma

Involvement of the cecum or rectum is most common with anal and rectal lymphoma frequent in AIDS patients

*Creator’s note:
Similar to SB lymphoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Account for nearly all mesenchymal tumors of the colon

A

Gastrointestinal stromal tumors (GISTs)

True colonic leiomyomas and leiomyosarcomas are very rare

GISTs are much less common in the colon than in the stomach and small bowel

May appear as exophytic, mural, or intraluminal masses

Ulceration is relatively frequent

Hemorrhage, cystic change, necrosis, and calcification are more common in larger tumors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Most common submucosal tumor of the colon

It is most frequent in the cecum and ascending colon

Nearly 40% present with intussusception

A

Lipoma

Barium studies demonstrate a smooth, well-defined elliptical filling defect, usually 1 to 3 cm in diameter

The tumors are soft and change shape with compression

CT or MR demonstration of a fat density tumor is definitive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Extrinsic lesions that commonly cause mass effect on the colon that may simulate intrinsic disease

A

Endometriosis
Benign and malignant pelvic masses
Extrinsic inflammatory process (appendicitis, pelvic abscess, diverticular abscess, PID)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

This is uncommon idiopathic inflammatory disease involving primarily the mucosa and submucosa of the colon

The disease consists of superficial ulcerations, edema, and hyperemia

A

Ulcerative colitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the radiographic hallmarks of ulcerative colitis

A

Granular mucosa
Confluent shallow ulcerations
Symmetry of disease around the lumen
Continuous confluent diffuse involvement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

In ulcerative colitis

What causes the granular pattern?

A

Early fine, granular pattern is produced by mucosal hyperemia and edema that precedes ulceration

A coarse granular pattern is produced later by the replacement of diffusely ulcerated mucosa with granulation tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

In ulcerative colitis

After mucosal hyperemia and edema, what is the next tissue changes?

A

Superficial ulcers spread to cover the entire mucosal surface

The mucosa stippled with barium adhering to the superficial ulcers

32
Q

In ulcerative colitis

These are deeper ulcerations of thickened edematous mucosa with crypt abscesses extending in the submucosa

A

Collar button ulcers

33
Q

Late changes of ulcerative colitis

A

Late changes include a variety of polypoid lesions

Pseudopolyps are mucosal remnants in areas of extensive ulceration

34
Q

In ulcerative colitis

Theses are small islands of inflamed mucosa

A

Inflammatory polyps

Postinflammatory polyps are mucosal tags that are seen in quiescent phases of the disease

35
Q

In ulcerative colitis

These are postinflammatory polyps with a characteristic worm-like appearance

A

Filiform polyps

36
Q

Pattern of involvement of ulcerative colitis

A

Involvement typically extends from the rectum proximally in a symmetric and continuous pattern

37
Q

What happens to the terminal ileum in ulcerative colitis?

A

The terminal ileum is nearly always normal

Rare backwash ileitis may produce an ulcerated but patulous terminal ileum

38
Q

CT findings of ulcerative colitis

A
  1. Wall thickening, often with “halo sign” of low- density submucosal edema
  2. Narrowing of the lumen of the colon
  3. Pseudopolyps, and pneumatosis coli with megacolon
39
Q

Complications of ulcerative colitis

A
  1. Strictures, usually 2 to 3 cm or more in length and commonly involving the transverse colon and rectum
  2. Colorectal adenocarcinoma, with an approximate risk of 1% per year of disease
  3. Toxic megacolon (2% to 5% of cases) may be the initial manifestation
  4. Massive hemorrhage
40
Q

Associated extraintestinal diseases of ulcerative colitis

A

Sacroiliitis mimicking ankylosing spondylitis (20% of cases)
Eye lesions including uveitis and iritis (10% of cases)
Cholangitis
Increased incidence of thromboembolic disease

41
Q

Hallmark of Crohn colitis

A
  1. Early aphthous ulcers
  2. Later confluent deep ulcerations
  3. Predominant right colon disease
  4. Discontinuous involvement with intervening regions of normal bowel
  5. Asymmetric involvement of the bowel wall
  6. Strictures
  7. Fistulas
  8. Sinus formation
42
Q

In Crohn disease

How is pseudodiverticula formed?

A

Pseudodiverticula of the colon are formed by asymmetric fibrosis on one side of the lumen, causing saccular outpouches on the other side

43
Q

In Crohn disease

What is the rectal finding?

A

Involvement of the rectum is characterized by deep rectal ulcers and multiple fistulous tracts to the skin

44
Q

Colonic disease that may be caused by a variety of bacteria (Salmonella, Shigella, Escherichia coli), parasites, viruses (cytomegalovirus, herpes), and fungi (histoplasmosis, mucormycosis)

Most cause a pancolitis with edema and inflammatory wall thickening with infiltration of pericolonic fat

A

Infectious colitis

Pericolonic fluid and intraperitoneal fluid may be present

45
Q

This is a potentially fatal condition characterized by marked colonic distention and risk of perforation

It occurs as a complication of fulminant colitis often caused by ulcerative colitis, Crohn disease, pseudomembranous colitis, use of antidiarrheal drugs, and hypokalemia

A

Toxic megacolon

Transmural inflammation causes deep ulcers that may extend to the serosa surface, large areas of denuded mucosa, and loss of muscle tone

46
Q

Radiographic finding of toxic megacolon

A
  1. Marked dilation of the colon (transverse colon >6 cm) with absence of haustral markings
  2. Edema and thickening of the colon wall
  3. Pneumatosis coli
  4. Evidence of perforation

Barium studies should be avoided because of risk of perforation

47
Q

This is an inflammatory disease of the colon, and occasionally involving the small bowel, characterized by the presence of a pseudomembrane of necrotic debris and overgrowth of Clostridium difficile

A

Pseudomembranous colitis

Disease presents as fulminant inflammatory bowel disease with diarrhea and foul stools

48
Q

Causes of pseudomembranous colitis

A

Antibiotics (any that change bowel flora)
Intestinal ischemia (especially following surgery)
Irradiation
Long-term steroids
Shock
Colonic obstruction

49
Q

Conventional radiographs of pseudomembranous colitis

A
  1. Dilated colon
  2. Nodular thickening of the haustra
  3. Ascites

*Creator’s notes:
Nonspecific

50
Q

Barium enema finding of pseudomembranous colitis

A

Irregular lumen with thumbprint indentations similar to ischemic colitis
Superficial ulcers are common
Plaque-like defects on the mucosal surface are due to the pseudomembranes

51
Q

CT scan finding pf pseudomembranous colitis

A
  1. Marked wall thickening up to 30 mm (average 15 mm) with halo or target appearance
  2. Characteristic stripes of intraluminal contrast media trapped between nodular areas of wall thickening (the “accordion sign”)
  3. Mild pericolonic fat inflammation disproportionate with the marked colonic wall inflammation
  4. Ascites (35%)
52
Q

“Accordion sign” is seen on what disease?

A

Pseudomembranous colitis

Stripes of intraluminal contrast media trapped between nodular areas of wall thickening

53
Q

Barium study finding of amebiasis

A 
Aphthous ulcers
Deep ulcers 
A symmetric disease
Skip areas
(mimic's Crohn colitis)

The cecum and rectum are the primary sites of colonic disease

The terminal ileum is characteristically not involved

54
Q

Complications of amebiasis

A

Strictures
Amebomas consisting of a hard fixed mass of granulation tissue that may simulate carcinoma
Toxic megacolon
Fistulas, particularly following surgical intervention

55
Q

Also known as neurtopenic colitis

This is a potentially fatal infection of the cecum and ascending colon usually seen in patients who are neutropenic and immunocompromised by chemotherapy

A

Typhilitis

Concentric, often marked, thickening of the wall of the cecum and ascending colon with prominent pericolonic inflammatory changes are characteristic

Patients are at risk for colon ischemia

56
Q

Imaging finding of ischemic colitis

A

Early changes include thickening of the colon wall, spasm, and spiculation

As blood and edema accumulate within the bowel wall, multiple nodular defects are produced in a pattern called “thumbprinting”

CT demonstrates symmetrical or lobulated thickening of the bowel wall with an irregularly narrowed lumen

Submucosal edema may produce a low-density ring bordering on the lumen (target sign)

Air in the abnormal bowel wall (pneumatosis) is highly suggestive of ischemia

57
Q

Diseases that is due to chronic irritation of the mucosa by laxatives including castor oil, bisacodyl, and senna

The involved colon may be dilated and without haustra, or narrowed

The right colon is most commonly affected

Bizarre contractions are often observed

The diagnosis is made by clinical history

A

Cathartic colon

58
Q

Imaging findings of tubercolitis

A
  1. Marked thickening of the wall of the colon and terminal ileum
  2. Markedly enlarged lymph nodes, often with low central attenuation or calcification
  3. Common fistulae and sinus tracts
  4. Colitis may be segmental or diffuse
  5. Short strictures may mimic colon cancer
  6. Thickening of the peritoneum and extensive abdominal adenopathy suggest the disease

Findings mimic Crohn disease

59
Q

These are pedunculated fatty structures that occur in rows on the external aspect of the colon adjacent to the anterior and posterior taenia coli

A

Epiploic appendages

They occur in greatest concentration in the cecum and sigmoid colon sparing the rectum

Epiploic appendagitis is caused by ischemic infarction of these structures, often resulting from torsion

60
Q

CT finding of epiploic appendages

A
  1. 1- to 4-cm ovoid mass with central fat density and surrounding inflammation abutting the wall of the colon
  2. A hyperdense enhancing rim
    surrounds the mass (“ring sign”)
  3. Inflammatory changes may extend into the adjacent peritoneum
  4. A central high attenuation dot is often present representing the central thrombosed vessels
  5. Infracted tissue may eventually calcify
61
Q

Ring sign is seen on what disease?

A

Epiploic appendagitis

62
Q

This is an acquired condition in which the mucosa and muscularis mucosae herniate through the muscularis propria of the colon wall, producing a saccular outpouching

A

Colon diverticulosis

Diverticulosis without diverticulitis is a cause of painless colonic bleeding that may be brisk and life threatening

63
Q

Colon diverticula are classified as true diverticula

True or false

A

False

Colon diverticula are false diverticula because the sacs lack all of the elements of the normal colon wall

64
Q

Conventional abdominal radiographs findings of colonic diverticula

A

Gas-filled sacs parallel to the lumen of the colon

65
Q

Barium study finding of colonic diverticula

A

Barium- or gas-filled sacs outside the colon lumen
Sacs vary in size from tiny spikes to 2 cm in diameter
Most are 5 to 10 mm in diameter

They may occur anywhere in the colon but are most common and usually most numerous in the sigmoid colon

66
Q

Inflammation of diverticula, usually with perforation and intramural or localized pericolic abscess

A

Acute diverticulitis

Diverticulitis eventually complicates approximately 20% of the cases of diverticulosis.

67
Q

Complications of acute diverticulitis

A

Obstruction
Bleeding
Peritonitis
Sinus tract and fistula formation

68
Q

Diverticulitis is a less common cause of colon obstruction than is colon carcinoma

True or false

A

True

Obstruction due to diverticulitis is often temporarily relieved by smooth muscle relaxants such as glucagon

69
Q

Colon bleeding is less often associated with diverticulosis than diverticulitis

True or false

A

False

Bleeding is more common in diverticulosis

70
Q

Process of diverticular abscesses

What happens to them?

A

Most diverticular abscesses are quickly walled off and confined, but free perforation with pus and air in the peritoneal cavity and diffuse peritonitis may occur

Sinus tracts may lead to larger abscess cavities in the peritoneal or retroperitoneal compartments.

Fistulas are most common to the bladder, vagina, or skin, but may develop to any lower abdominal organ including fallopian tubes, small bowel, and other parts of the colon

71
Q

Barium enema examination for acute diverticulitis is considered safe except on what cases?

A

When signs of free intraperitoneal perforation or sepsis are present

72
Q

What are the hallmarks of diverticulitis on barium enema

A

Deformed diverticular sacs
Demonstration of abscess
Extravasation of barium outside the colon lumen

73
Q

What is “double tract sign” and what disease is it seen?

A

Barium leaks into the abscess cavities, or forms tracks paralleling the colon lumen and often connecting multiple perforated sacs

Seen in acute diverticulitis

74
Q

CT finding of acute diverticulitis

A
  1. Localized wall thickening
  2. Inflammation of pericolonic fat
  3. Pericolonic abscess
  4. Diverticula at or near the site of inflammation
  5. Common involvement of the adnexa with fluid collections and fistulae
75
Q

Screening examination of choice for confirming the presence of, and often localizing, lower GI bleeding

A

Radionuclide imaging studies

Technetium-99m sulfur colloid or Tc-99m-red blood cell studies are capable of detecting bleeding at rates below 0.1 mL/min

76
Q

Angiography requires bleeding rates of how many mL/min to be visualized?

A

0.5 mL/min or greater

Angiography is more specific than scintigraphy in demonstrating the anatomic cause of bleeding and offers the possibility of nonoperative treatment by embolization.

77
Q

This refers to ectasia and kinking of mucosal and submucosal veins of the colon wall

The condition results from a chronic intermittent obstruction of the veins where they penetrate the circular muscle layer

A

Angiodysplasia

A maze of distorted, dilated vascular channels replaces the normal mucosal structures and is separated from the bowel lumen only by a layer of epithelium

Gastrointestinal Imaging (Beri) (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions