Ulcerative colitis (UC) is one of the 2 major types of inflammatory bowel disease ( IBD), along with Crohn disease. Unlike Crohn disease, which. The disease is further classifiedinto two types, ulcerative colitis (UC) and Crohn’s Keywords: inflammatory bowel disease, diagnosis terkini, kolitis ulseratif. Ulcerative colitis is a chronic inflammatory disease of the colon with an increasing incidence worldwide. The medical management of this disease continues to.
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Radiographical modalities have become important diagnostic tools in cases of ulcerative colitis UC. Imaging can be used non-invasively to determine the extent of involvement, severity of disease and to detect disease-related complications and extra-intestinal inflammatory bowel kolitie IBD manifestations.
While abdominal X-rays and barium enemas still retain their relevance in specific clinical settings, the use of computed tomography enterography CTE or magnetic resonance enterography MRE are now used as first-line investigations to exclude active small bowel disease in IBD patients and can be utilized to detect active colonic inflammation.
Ultrasonography, leukocyte scintigraphy and positron emission adlah are novel abdominal imaging modalities currently being explored for IBD interrogations. This plethora of radiological imaging options has become a vital component of UC assessments.
Ulcerative colitis – Symptoms and causes – Mayo Clinic
Radiographical evaluations are a key component of diagnostic and management algorithms in patients with inflammatory bowel disease IBD. In contrast, ulcerative colitis UC involves the rectum, often extending proximally in a continuous fashion throughout the colon [ 1 ]. Radiological testing in UC can be used as an alternative to endoscopic assessments, when tissue acquisition is not needed, providing data on disease activity, extent and severity.
There is a wide range of options available to clinicians, with the correct modality often being selected, based on both intrinsic test and patient-specific features. This review will explore the role of radiological imaging in the evaluation and management of UC.
Imaging can assist in the non-invasive determination of the extent and severity of disease and identify complications such as toxic megacolon and intestinal perforation.
Radiographical techniques can be utilized after colectomy to evaluate ileo-anal pouch function and anatomy. Potential applications include predicting the need for colectomy or response to medical therapy and assessing bone health in IBD patients at risk for osteopenia or osteoporosis [ 2 ]. Abdominal X-rays AXRs are widely available and can provide crucial information in the acute setting. AXRs are typically performed without the use of intravenous, oral, or rectal contrast. Indications include assessing for perforation of the viscus and toxic megacolon [ 34 ].
If perforation is a clinical concern, both supine and upright films should be requested. In patients unable to stand for an upright film, left decubitus positioning is an alternative strategy. Dilatation is typically most evident in the transverse colon, the least-dependent portion of the colon on supine films [ 5 ].
Other features of active inflammation include colonic air—fluid levels or loss of colonic haustration [ 4 ]. In the presence of severe disease, the colon may exhibit an irregular, nodular contour with mucosal islands separated by severely inflamed mucosa Figure 1 a [ 6 ].
Lastly, AXRs may suggest the extent of disease, as an inflamed colon contains less stool and absence of stool in the colon suggests pancolitis [ 6 ].
A year-old female patient with ulcerative colitis presenting with abdominal pain and bloody diarrhea. Abdominal X-ray depicting areas of thumbprinting white arrow suggestive of colonic bowel wall edema.
Computed tomography demonstrating free air white arrow and colon wall thickening white arrowhead. The presence of intraperitoneal air is more likely to be missed on abdominal X-ray films and abdominal CT has demonstrated a higher diagnostic yield for detecting IBD-related complications Figure 1 b. Barium enema BE is a retrograde colonic assessment that can be done as either a single- or double-contrast study.
A double-contrast BE—which is preferable except in cases of severe colitis—utilizes smaller amounts of high-density barium, followed by air insufflation. Double contrast ensures that the mucosa is coated with a thin layer of barium, while the lumen remains distended with air. It can be used to asses for active inflammation and to determine the extent of disease, but the role of BE has been reduced with the widespread availability of endoscopy.
Barium enemas can also interrogate colonic strictures that preclude the passage of an endoscope. Information obtained in this setting includes stricture length, diameter and status of the colon proximal to the stricture. Multiple inflammatory features have been described in the literature, including a fine mucosal granularity Figure 2 caused by edema and hyperemia [ 5 ].
Adherence of flecks of barium to superficial erosions or ulcers superimposed on a background of mucosal irregularity may give an appearance resembling the stippling of paint. Deeper ulcerations into the submucosa with lateral extension produce the appearance of collar-stud or collar-button ulcers [ 8 ]. With extension of the ulcers, intervening normal mucosa may protrude, to appear as polyps.
Chronic inflammation may result in shortening and narrowing of the colon and it can lose its interhaustral folds, resulting in a featureless or tubular appearance.
Radiographical evaluation of ulcerative colitis
Other koligis changes due to chronic inflammation include widening of the presacral retrorectal space as seen on a lateral film of the rectum. Double contrast barium enema illustrating granular mucosa in a patient with active ulcerative colitis. Courtesy of Stephen W. Ulseratlf a prospective study by Loose et al. CTC identified abnormalities proximal to a stenotic region in nine cases not visualized on BE which required medical or surgical intervention.
Standard CT can be performed with or without intravenous contrast, depending on the clinical setting. In comparison, CTE involves ingestion of large-volume neutral oral contrast agent along with iodinated intravenous contrast, typically in the enteric phase 50 seconds after injectionto maximize the visualization of enhancing intestinal lesions and inflammation.
CTC requires a colonic cathartic preparation and colonic ulserstif with air insufflation administered via a rectal tube.
CTC is designed for colonic rather than small bowel assessments. There are multiple potential applications for CT in UC patients. CTC has also been utilized to assess colonic disease activity. Biomechanical computed tomography is a novel image-analysis method that can measure bone strength in combination with a CTE or CTC protocol.
The radiological hallmark of active UC is the presence of colonic mural thickening and enhancement. Normal colonic wall diameter is in the range of 2—3 mm, whereas a mean wall thickness of 8 mm has been reported in UC patients with active disease Figure 1 b [ 1112 ]. Radiological features of UC may also include rectal narrowing, widening of presacral space and stranding of perirectal fat [ 13 ].
Computed tomography enterography in a year-old female with pancolonic ulcerative colitis. White arrow highlights region with wall thickening and enhancement.
There is a paucity of comparative CT data among studies of UC patients. The utility of CT non-enterography protocol in assessing the severity of UC was compared in 23 UC patients undergoing colonoscopy. Overall, the limited data on CT assessments in UC support endoscopy as the standard of care for the assessment of disease activity, extent, and severity. CT is preferred to endoscopy in UC patients with impassable stenoses, comorbidities where colonoscopy is contra-indicated, or suspected disease complications such as perforation [ 1819 ].
For small bowel interrogations, large-volume enteric contrast agents can be administered orally MRE or via a nasojejunal tube MR enteroclysis [ 15 ]. Glucagon or other anti-peristaltic agents are often administered to alleviate motion artifact related to bowel peristalsis. MR colonography can be performed after a cathartic colon preparation has been given.
Use of diffusion-weighted imaging with magnetic resonance colonography DWI-MRC —a technique adapah assesses changes in water diffusion—has been reported to assist with the detection of colonic inflammation in UC without requiring a bowel preparation [ 20 ].
This may vary depending on the MR technique, severity of inflammation and the chronicity of disease [ 22 ]. Mild active colonic disease may exhibit subtle thickening of the colonic wall and reduced distensibility. Moderate-to-severe disease may demonstrate thickening of the intestinal wall, mural edema, ulcerations, loss of haustra, mural hyperenhancement, engorged vasa recta comb sign and enlarged pericolonic lymph nodes Figure 4 [ 22 ].
Increased disease chronicity has been described as resulting in loss of haustra, smooth contours, tubular narrowing, rigidity and fatty proliferation limited to a widened perirectal space [ 22 ulseratir. Magnetic resonance enterography in a year-old male with ulcerative colitis.
Colonic wall thickening white arrow and hyperenhancement of the right colon. Engorgement of the pericolonic vasa recta white arrow with colonic wall thickening and hyperenhancement in the sigmoid colon. MRI in UC patients has been assessed with colonoscopy as the reference standard. Less optimal performance was described in an MRC study by Schreyer and colleagues, in which patients received rectal contrast as a gadolinium enema [ 24 ]. Sensitivity on a per-segment analysis for active colonic inflammation in UC patients was only By comparison, utilizing a water enema for colonic distension, Ajaj et al.
Independent predictors for endoscopic activity on a segment basis were relative contrast enhancement RCEpresence of bowel wall edema, enlarged lymph nodes ulsdratif the presence of engorged peri-enteric vasculature comb sign. Ultrasonography US is a relatively new modality as applied to intestinal imaging. Oral bowel preparation is typically not required or utilized before a routine abdominal US [ 31 ].
Fasting six hours prior to the examination reduces air in the bowel that may hamper the examination.
Oral administration of agents such as polyethylene glycol may improve image quality and diagnostic accuracy [ 32 ]. Intravenous contrast is utilized in some specialized centers, but it is not FDA approved for intestinal assessments in the United States.
The technique of colon hydrosonography has been described and involves instillation of water into the rectum [ 32 ]. US for IBD often requires high-frequency 5—17 MHz linear array probes to increase spatial resolution and to allow adequate assessment of the intestinal wall [ 33 ]. Doppler interrogations provide additional vascular information and may assist with differentiating predominantly inflammatory from fibrostenotic lesions. Several potential indications for ultrasound exist for patients with ulcerative colitis.
It has the advantages of avoiding exposure to ionizing radiation, it is low cost and it is well tolerated by patients. The ileocecal region, sigmoid- ascending- and descending colons are adequately visualized in most patients, whereas visualizing the entire transverse colon can be challenging because of its variable anatomy and position.
The rectum can be difficult to evaluate due to its position in the pelvis [ 33 ]. US has been utilized to define the anatomical location and severity of UC in patients with established disease and to assess for penetrating complications [ 34 ]. It In a small study of 26 consecutive patients with steroid refractory or dependent UC, who were treated with granulocyte and monocyte adsorption apheresis, increased bowel wall vascularity on contrast-enhanced US correlated with clinically assessed non-response to cytapheresis [ 35 ].
Finally, endoscopic ultrasonography utilizing a catheter probe has been explored in terms of predicting response to medical therapy in severe UC cases [ 36 ]. Multiple features of active colonic inflammation have been described, based on US images.
Additionally, creeping fat and enlarged lymph nodes are less frequently described with UC, compared with CD [ 34 ]. The imaging performance of ultrasound in UC has been compared with other modalities. The concept of mucosal healing is an emerging treatment goal in IBD. The ability of US to assess responses to medical therapy was prospectively studied in UC patients with moderate-to-severe disease.
Seventy-four patients, clinically responsive to corticosteroids, underwent follow-up colonoscopy and intestinal US at 3, 9 and 15 months. Additionally, a role for US in prognostication was also suggested by the study.
Moderate-to-severe endoscopic and US scores at 3 months were associated with a high risk of endoscopic activity at 15 months odds ratio OR: Scintigraphy is an imaging method that relies on radiotracers radioactive isotopes to detect active inflammation. Leukocyte scintigraphy utilizes physiological leukocyte migration to areas of active inflammation.