Inflammatory Bowel Disease. Inflammatory bowel disease (IBD) is an idiopathic disease, probably...

Inflammatory Bowel Inflammatory Bowel DiseaseDisease

Inflammatory Bowel DiseaseInflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an idiopathic disease, probably involving an immune reaction of the body to its

own intestinal tract.

The 2 major types of IBD are ulcerative colitis ulcerative colitis (UC)(UC) and Crohn diseaseCrohn disease (CD) (CD).

Frequency:

In the US: • Approximately 1 million people in the United States have UC or CD. • The prevalence of IBD among Americans of African descent is estimated to be

the same as the prevalence among Americans of European descent. • The prevalence is lower among Americans of Asian and Hispanic descent. Internationally: • The incidence of IBD is assumed to be highest in developed countries and

lowest in the developing regions of the world.

Crohn diseaseCrohn disease

• CD consists of segmental involvement by a nonspecific granulomatous

inflammatory process. • The most important pathologic feature is involvement of all layers of the bowel,

not just the mucosa and the submucosa, as is characteristic of UC. • CD is discontinuous, with skip areas interspersed between one or more involved

areas. • Late in the disease, the mucosa develops a cobblestone appearance, which

results from deep longitudinal ulcerations interlaced with intervening normal

mucosa.


The 3 major patterns of involvement in CD are:

1. disease in the ileum and cecum, occurring in 40% of patients

2. disease confined to the small intestine, occurring in 30% of patients

3. disease confined to the colon, occurring in 25% of patients.

• Rectal sparing is a typical but not constant feature of CD. However, anorectal

complications (eg, fistulas, abscesses) are common. • Much less commonly, CD involves the more proximal parts of the GI tract,

including the mouth, tongue, esophagus, stomach, and duodenum.

CD causes 3 patterns of involvement:

1. inflammatory disease,

2. strictures

3. fistulas.


Crohn diseaseCrohn disease

• Inflammation always begins in the

rectum, extends proximally a certain

distance, and then abruptly stops. • A clear demarcation exists between

involved and uninvolved mucosa. • The rectum is always involved in UC,

and no "skip areas"no "skip areas" are present. • UC primarily involves the mucosa

and the submucosa, with formation

of crypt abscesses and mucosal

ulceration.

UUlcerative colitislcerative colitis


• UC remains confined to the rectum in approximately 25%

of cases. In the remainder of cases, UC spreads

proximally and contiguously. • Pancolitis occurs in 10% of patients. • The small intestine is never involved, except when the

distal terminal ileum is inflamed in a superficial manner,

referred to as backwash ileitis. • As the disease becomes chronic, the colon becomes a

rigid foreshortened tube that lacks its usual haustral

markings, leading to the lead pipe the lead pipe („(„stove-pipestove-pipe”)”)

appearanceappearance observed on barium enema. • The skip areasThe skip areas (ie, normal areas of the bowel

interspersed with diseased areas) observed in CD of the

colon do not occur in UC.do not occur in UC.


UUlcerative colitislcerative colitis

• UC and CD are generally diagnosed using clinical, endoscopic, and histologic criteria. • No single finding is absolutely diagnostic for one disease or the other. • Approximately 20% of patients have a clinical picture that falls between CD and UC;

they are said to have indeterminate colitis.

Distinguishing Features of CD Versus UC

Features Crohn Disease Ulcerative Colitis

Skip areas Common Never

Cobblestone mucosa Common Rare

Transmural involvement

Common Occasional

Rectal sparing Common Never

Perianal involvement Common Never

Fistulas Common Never

Strictures Common Occasional

Granulomas Common Occasional


Distinguishing Features of CD Versus UCDistinguishing Features of CD Versus UC

UCCD


Imaging StudiesImaging Studies - - plain radiography plain radiography The role of plain radiography is fairly limited. The 2 major purposes that it serves are: 1. to assess the presence of intestinal obstruction and 2. to evaluate pneumoperitoneum prior to further radiological workup.


Toxic megacolonToxic megacolon is a complication of inflammatory bowel disease. It is due to transmural inflammation with loss of neuromuscular function.

The appearances and the extent indicate a pancolitis.pancolitis.

The transverse colon measures more than 5.5 cm across, which in the presence of colitis indicates a toxic megacolon, with the risk of imminent perforation - It constitutes a surgical emergency. It constitutes a surgical emergency.

There is loss of the normal mucosal outline to the large bowel, with an irregular margin and no visible haustral markings, indicating mucosal inflammation and oedema. There is marked dilatation of the large bowel, from the caecum on the right to a loop of sigmoid seen centrally in the pelvis.


There is a high congruence (95%) between the

radiological and endoscopic diagnosis.

Although generally safe and well tolerated, DCBE (Double

Contrast Barium Enema) is relatively contraindicated in

patients with severe colitis as it may precipitate toxic

megacolon or perforation.


Normal barium enema findings virtually exclude active ulcerative colitis, whereas abnormal findings can be diagnostic.

Several terms have been used to describe abnormalities found after barium studies of the colon. These include:

1. a “stove-pipe”a “stove-pipe” appearance, which suggests chronic colitis that has resulted in a loss of colonic haustrae;

2. “rectal sparing”“rectal sparing”, which suggests Crohn colitis in the presence of inflammatory changes in other portions of the colon;

3. “thumbprinting”“thumbprinting”, which indicates mucosal inflammation

4. “skip lesions”“skip lesions” (discontinuous disease), which suggests areas of inflammation alternating with normal-appearing areas, again suggesting Crohn colitis

Inflammatory Bowel DiseaseInflammatory Bowel DiseaseImaging StudiesImaging Studies - DC b - DC barium enema arium enema

Giant barrel sponge (Xestospongia muta)Stove-pipe sponge (Aplysina archeri)

a “stove-pipe” appearancea “stove-pipe” appearance - ulcerative colitis

ulcerative colitis


““rectal sparingrectal sparing”” - Crohn colitis

The film shows a narrowing of the descending colon, as well as an area of narrowing with speculation in the splenic flexure.

The areas of “skip lesions” are typical of a diagnosis of Crohn’s disease. Crohn colitis


Bowel wall "thumbprinting""thumbprinting" is a radiological sign of thickening of the colonic wall.

It occurs secondary to submucosal haemorrhage and oedema from capillary leakage

This sign can also be seen frequently on the abdominal flat plate Intestinal “thumbprinting”of the

transverse colon.


http://images.google.pl/imgres?imgurl=http://news.bbc.co.uk/olmedia/1465000/images/_1468769_thumb150.jpg&imgrefurl=http://news.bbc.co.uk/hi/english/sci/tech/newsid_1468000/1468769.stm&h=180&w=150&sz=9&tbnid=3XAwsoywyVsJ:&tbnh=96&tbnw=80&hl=pl&start=11&prev=/images%3Fq%3Dthumbprinting%26svnum%3D10%26hl%3Dpl%26lr%3D%26sa%3DG

The irregular involvement in the colon, skip lesions, and the string sign – Crohn disease.

Crohn colitis


Crohn colitis

fissures and string sign„cobblestone” appearance

aphthous ulcers


Imaging StudiesImaging Studies - DC b - DC barium enema arium enema

ulcerative colitis

inflammatory pseudopolyps

normal mucosa

superficial ulcerations

extensive ulcerations

granular mucosa


Barium Enema Findings In Inflammatory Bowel DiseaseBarium Enema Findings In Inflammatory Bowel Disease


The small bowel series, with or without an upper gastrointestinal

tract series, provides invaluable information about Crohn disease.

The small bowel series is usually sufficient for the evaluation of

small intestine Crohn disease

This study can reveal if inflammation is present, can assist in the

assessment of stricture length and severity, and can help decide

the most appropriate surgical approach.

Fistulae are often demonstrated on films from a small bowel series,

even if they are not suggested based on the clinical evaluation.

Inflammatory Bowel DiseaseInflammatory Bowel DiseaseSmall bowel series/small bowel follow-through Small bowel series/small bowel follow-through

Small bowel series/small bowel follow-through Small bowel series/small bowel follow-through

Changes of early/intermediate Crohn's disease, with thickened folds, tending to asymmetry and obliteration in places.


The enteroclysis differs from a small bowel series in that a nasoenteric

or oroenteric tube is placed and contrast is instilled directly into the

small intestine.

This is usually performed when fine detail of the intestinal mucosa is

required or the distal small intestine is not adequately seen on the

small bowel series because the contrast is diluted as it passes through

the (usually dilated) small bowel.

Inflammatory Bowel DiseaseInflammatory Bowel DiseaseSmall bowel enteroclysis Small bowel enteroclysis

Small bowel enteroclysis Small bowel enteroclysis

Conventional posteroanterior enteroclysis image shows a long high-grade stricture of a jejunal loop (arrowheads) and a jejunocolic fistula (arrows)

From: Radiology. 2000;215:717-725. Small-Bowel Disease: Comparison of MR Enteroclysis Images with Conventional Enteroclysis and Surgical Findings H. W. Umschaden et al.


• CT scanning of the abdomen and pelvis has limited use in the diagnosis of

IBD, but findings may be very suggestive of IBD.

• Wall thickening on CT scans is nonspecific and may occur from smooth

muscle contraction alone, especially in the absence of other

extraintestinal inflammatory changes; however, the presence of

inflammatory changes significantly increases the predictive value of the

CT scan.

• CT scanning is the ideal study to determine if the patient has abscesses,

and it can be used to guide percutaneous drainage of these abscesses.

Inflammatory Bowel DiseaseInflammatory Bowel DiseaseCT SCANCT SCAN

Typical appearances of active Crohn disease. Transverse CT images show segmental

luminal narrowing, mural thickening (arrows), mucosal hyperenhancement (arrowhead), and

low-grade partial small bowel obstruction.

Small bowel follow-through image shows eccentric narrowing and string sign (arrows) in the same bowel loop.

From: Radiology 2003;229:275-281. Assessment of Small Bowel Crohn Disease: Noninvasive Peroral CT Enterography Compared with Other Imaging Methods and Endoscopy Peter B. Wold, et al.

Inflammatory Bowel DiseaseInflammatory Bowel DiseaseCAT SCANCAT SCAN

CAT SCANCAT SCAN

CT enteroclysis


Traditionally, MRI has had a well-defined role in evaluation of anorectal

complications of Crohn disease.

Recently, the development of faster pulse sequences (eg, single-shot fast

spin-echo and gradient-echo sequences) and higher-gradient systems has

made T1- and T2-weighted breath-hold imaging possible. This breath-hold

imaging has been a major breakthrough in overcoming physiologic motion

artifacts in abdominal imaging. It has made routine abdominal MRI feasible.

Because of a decrease in cumulative radiation exposure and because of the

possibility of attaining high-quality coronal images correlating with barium

studies, MRI is currently being investigated for monitoring disease activity

in Crohn disease.

Inflammatory Bowel DiseaseInflammatory Bowel DiseaseMRIMRI

MRIMRI

Active Crohn disease in the terminal ileum. Narrowing of the involved bowel segment with prestenotic dilatation is shown on conventional

enteroclysis (a), postgadolinium three-dimensional FLASH (b), and true FISP (c) images.

From: Radiographics. 2001;21:S161-S172. MR Enteroclysis Imaging of Crohn Disease Panos Prassopoulos, MD et al.


• US features are nonspecific and include bowel wall thickening,

which may involve both the hypoechoic muscular coat and the

echogenic mucosa.

• There is longitudinally extending wall thickening, with

decreased echogenicity and luminal narrowing.

• Localized perforation may lead to the formation of an abscess,

which may be clinically silent if the patient is receiving steroid

therapy.

UltrasoundUltrasound


Capsule enteroscopy:

This technique is performed by having the patient swallow an encapsulated video camera that transmits images to a receiver outside the patient.

Most commonly used for finding obscure sources of gastrointestinal blood loss, the images can find ulcerations associated with Crohn disease if upper endoscopy and colonoscopy are unrevealing.

The major risk in patients with Crohn disease is the potential for the camera to become lodged at the point of a stricture, which could require operative intervention for removal.


AA study published in the June issue of The American Journal of study published in the June issue of The American Journal of Gastroenterology (Volume 98, Issue 6) concludes that capsule Gastroenterology (Volume 98, Issue 6) concludes that capsule

endoscopy is better than enteroclysis in diagnosing small bowel endoscopy is better than enteroclysis in diagnosing small bowel ulcers. ulcers.

"The results of this study indicate that wireless capsule endoscopy is better than enteroclysis in the diagnosis of small bowel ulcers. Wireless

capsule endoscopy is the new gold standard for detecting Crohn’s disease in the small bowel."

said Douglas K. Rex, M.D., F.A.C.G., Professor of Medicine, Division of Gastroenterology and Hepatology, Department of Medicine, Indiana University School of Medicine, and

President-elect of the American College of Gastroenterology (ACG).

„CONCLUSION: In patients without a small-bowel stricture at barium study, more small-bowel disease was found at CE when findings were retrospectively compared with barium examination and CT findings.”

Radiology 2004;230:260. Small Bowel: Preliminary Comparison of Capsule Endoscopy with Barium Study and CT Amy K. Hara et al.


The FDA’s decision, together with peer reviewed The FDA’s decision, together with peer reviewed

publications, confirm that Capsule Endoscopy publications, confirm that Capsule Endoscopy

should be the first line diagnostic tool to evaluate should be the first line diagnostic tool to evaluate

patients with persistent abdominal symptoms patients with persistent abdominal symptoms

following a negative upper and lower endoscopy.following a negative upper and lower endoscopy.


Diverticular DiseaseDiverticular Disease


Diverticular disease of the colon begins as diverticulosisdiverticulosis

(colonic outpouchings), which may develop into

diverticulitisdiverticulitis (diverticular inflammation and perforation).


• Diverticular disease is the most common colon diseaseis the most common colon disease in Western nations. In the West, colonic diverticula occur in 5% of the population by the time individuals are aged 40 years.

• They affect 33-50% of the population older than 50 years and more than 50% of the population older than 80 years.

• Diverticulitis is the most common complication of diverticulosisDiverticulitis is the most common complication of diverticulosis, and it has been reported in 10-20% of patients with diverticulosis.

• Approximately 20% of patients with diverticulitis require surgical treatment.

• In underdeveloped nations in Asia and Africa, diverticulosis In underdeveloped nations in Asia and Africa, diverticulosis occurs in less than 0.2% of the population.occurs in less than 0.2% of the population. This low rate is probably the result of a high-fiber diet.


• Diverticula can be either acquired or congenital, and it can affect

either the small intestine or the large intestine.

• Acquired diverticula are more common and consist of herniation

of the mucosa and submucosa through the muscularis, usually at

the site of a nutrient artery.

• Diverticula involve the sigmoid colon in as many as 95%sigmoid colon in as many as 95% of

patients with diverticulosis. The cecum is involved in 5% of

patients.


The appearance of diverticula varies with the projection in which they are viewed and with the amount of air and barium they contain.

• In profile, a diverticulum appears as a protrusion outside of the protrusion outside of the coloncolon that is joined to the colonic wall by a neck.

• En face, a diverticulum may appear as a well-defined collection a well-defined collection of bariumof barium or as a ring shadowa ring shadow. It may resemble a bowler hat.

Barium study Barium study


The appearance of diverticula varies with the projection in which they are viewed and with the amount of air and barium they contain.

• In profile, a diverticulum appears as a protrusion protrusion outside of the colonoutside of the colon that is joined to the colonic wall by a neck.

• En face, a diverticulum may appear as a well-a well-defined collection of bariumdefined collection of barium or as a ring shadowa ring shadow. It may resemble a bowler hat.


DiverticulitisDiverticulitis

A single-contrast A single-contrast examination is the preferredexamination is the preferred method in patients in whom diverticulitis is suspected.


Many features of diverticulitis are depicted on barium enema images.

Narrowing, deformity, or Narrowing, deformity, or displacement of the bowel lumendisplacement of the bowel lumen is commonly seen.



On barium enema examination, diverticulitis can be diagnosed by recognizing a perforated a perforated diverticulumdiverticulum.

Barium may track through a perforated diverticulum into a sinus tract, fistulafistula, or abscess. Less commonly, it may extravasate freely into the peritoneum.

Single-contrast barium enema study demonstrates sigmoid diverticulitis with a colovesical fistula. Note the contrast material in the bladder.


On barium enema examination, diverticulitis can be diagnosed by recognizing a perforated a perforated diverticulumdiverticulum.

Barium may track through a perforated diverticulum into a sinus tract, fistula, or abscessabscess. Less commonly, it may extravasate freely into the peritoneum.

Single-contrast barium enema study in a patient with diverticulitis demonstrates an

intramural abscess filling with barium.


DiverticulitisDiverticulitisThe preferred examination is The preferred examination is CT scanningCT scanning of the of the

abdomen and pelvis.abdomen and pelvis.

CT findings can help in confirming clinical suspicion of diverticulitis and in excluding other abdominal or

pelvic disease.

The most common CT The most common CT finding is finding is paracolic fat paracolic fat stranding. stranding.

The fat stranding characteristically is disproportionately more severe than the relatively mild, focal colonic wall thickening.


Diverticulitis. Axial CT image of a man with left-sided diverticulitis shows severe pericolonic fat stranding that is greater than the degree of wall thickening of the descending colon.

A "normal" diverticulum (open arrow) and a ill-defined (fuzzy) diverticulum (solid straight arrow) are also seen.

From: „Disproportionate Fat Stranding: A Helpful CT Sign in Patients with Acute Abdominal Pain” J. M. Pereira et al. RadioGraphics 2004;24:703-715

DiverticulitisDiverticulitisThe inflammatory process can result in accumulation of fluid in the root of the sigmoid mesentery, which appears on CT scans as the "comma sign"the "comma sign", and engorgement of the mesenteric vessels, which appears as the "centipede sign".

Diverticulitis and the comma sign. Axial nonenhanced CT image of a 47-year-old patient with cecal diverticulitis shows thickening of the lateral conal fascia, a finding known as the reverse comma sign (arrowhead). Note the mild wall thickening of the cecum (small arrow)

and a diverticulum (large arrow).



Diverticulitis and the centipede sign. Axial contrast-enhanced CT image of a patient with diverticulitis shows engorgement of the vasa recta that feeds the sigmoid colon, a finding

known as the centipede sign (open arrows). Note also the mild wall thickening of the colon (long solid arrow), diverticula (arrowheads), and fluid at the root of the sigmoid mesentery (short solid

arrow).

The inflammatory process can result in accumulation of fluid in the root of the sigmoid mesentery, which appears on CT scans as the "comma sign", and engorgement of the mesenteric vessels, which appears as the the "centipede sign""centipede sign" .


The most important entity in the differential diagnosis to exclude is colon adenocarcinoma.


Differentiating Features of Diverticulitis and Colon Adenocarcinoma on CT:


The most important entity in the differential diagnosis to exclude is colon adenocarcinoma.


Colon adenocarcinoma. Axial contrast-enhanced CT image shows severe wall thickening of the ascending colon with no fat stranding. This disproportionate degree of thickening suggests that the patient’s disease originates in the bowel wall.

The most common CT finding The most common CT finding is paracolic fat stranding.is paracolic fat stranding.


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