Ultrasound and magnetic resonance imaging assessmentof active bowel segments in Crohn's disease

AIM: Determining bowel disease activity in Crohn's patients can be difficult on clinical and laboratory assessment. Endoscopy is invasive and barium studies use ionising radiation. The aim of this study was to compare ultrasound and magnetic resonance imaging (MRI) in detecting Crohn's disease activity in the small or large bowel. MATERIALS AND METHODS: Thirty patients, previously diagnosed with Crohn's disease, had bowel ultrasound and MR imaging, and were deemed active or inactive on each test. The 'gold standard' was based on clinical assessment and one or more of the following: endoscopy, barium studies or surgery. RESULTS: For determining Crohn's disease activity, the sensitivities and specificities of bowel ultrasound and MRI were 87 percent and 100 percent, and 87 percent and 71 percent, respectively. Significant parameters that defined disease activity were bowel wall thickening on ultrasound and MRI, and contrast enhancement of the bowel wall and mesenteric vascularity/stranding on MRI. CONCLUSION: Ultrasound and MRI were both sensitive for determining Crohn's disease activity in the bowel, but MRI with gadolinium enhancement was less specific.     

Quantitative assessment of small bowel motility by nonrigid registration of dynamic MR images

Evaluation of small bowel motility from two-dimensional dynamic MRI is of increasing interest for the assessment of segmental diseases such as Crohn's disease. We propose to use nonrigid image registration for automated motility analysis. Registration is particularly difficult when localized intensity changes occur (e.g., due to intraluminal flow or through-plane motion). Therefore, displacements were extracted using a joint registration and modeling of intensity changes. Results were analyzed in 10 patients with known or suspected Crohn's disease. Bowel wall displacements were assessed by tracking bowel cross-sectional markers over time. Automated tracking with the proposed technique was in good agreement with manual tracking (similar bias, improved standard deviations). The ability to quantify different grades of bowel motility was investigated by comparing direct motion measures (i.e., changes in bowel cross-sectional diameter or area) and various parametric maps, e.g., based on the Jacobian of the measured displacements with expert grading. Among these measures, the standard deviation over time of the Jacobian was the best at predicting grades from 1 (moving normally) to 4 (not moving at all) in 50 bowel regions with normal and pathologically reduced motility, yielding 93% correct classification with a 1-class tolerance (i.e., same score as the expert ± 1).     

MRI in Crohn's disease

Technological developments have extended the role of MRI in the evaluation of the gastrointestinal tract. The potential of MRI to evaluate disease activity in Crohn's disease has been investigated extensively, as MRI has intrinsic advantages over other techniques, including noninvasiveness and the absence of ionizing radiation. For perianal fistulizing disease MRI has become a mainstay in evaluation of disease, as localization and extent of disease can be very well appreciated using both T2-weighted and T1-weighted sequences, fat suppression, and intravenous contrast medium. Imaging of the small bowel and colon in Crohn's disease is more complicated due to bowel peristalsis and respiratory movement. However, using fast breathhold sequences and intravenous spasmolytic medication, images of good diagnostic quality can be acquired. To obtain sufficiently distended bowel, which in our estimation is a prerequisite for evaluation of the bowel, MR enteroclysis can be performed. However, applicability of different oral contrast media has been studied, as a noninvasive method for bowel distension would be preferable. Abdominal MRI is a valuable imaging technique for evaluation of luminal, transmural, and extraintestinal manifestations of Crohn's disease as degree of disease activity, presence of luminal pathology (e.g., stenoses), and extraintestinal manifestations of disease (e.g., abscesses, fistulas) can be accurately assessed.     

Bowel wall thickening in patients with Crohn's disease: CT patterns and correlation with inflammatory activity

AIM: To assess CT patterns of bowel wall thickening in patients with Crohn's disease and to correlate these patterns with inflammatory activity. MATERIALS AND METHODS: We conducted a retrospective review of 58 helical abdominal CT scans of 53 patients with pathologically proven Crohn's disease. CT patterns of thickened bowel wall were divided into four types based on patterns of mural stratification and enhancement: type A, multilayered mural stratification; type B, two layers with strong mucosal enhancement and prominent low-density submucosa; type C, two layers without strong mucosal enhancement; and type D, homogeneous enhancement. We evaluated CT findings of the bowel and adjacent structures. We also reviewed pathologic features and clinical data to determine inflammatory activity. RESULTS: Fifty-five (95%) of 58 CT examinations showed bowel wall thickening. Of these 55 CT scans, type A pattern was found in 33 (60%), type B in 10 (18%), type C in five (9%), and type D in seven (13%). CT scans with type A showed significantly more wall thickening than those with either type C or type D. Histology revealed 43 cases with active disease and 12 with quiescent appearance. Thirty of 33 CT scans with type A and all 10 with type B were classified as acute disease, and three of five with type C and six of seven with type D as quiescent. CONCLUSION: In patients with Crohn's disease, CT patterns of bowel wall thickening correlated with inflammatory activity. Thickened bowel wall with layering enhancement is predictive of acute disease, and that of homogeneous enhancement suggests quiescence.     

Magnetic resonance imaging for evaluation of disease activity in Crohn’s disease: a systematic review

To systematically review the evidence on the accuracy of MRI for grading disease activity in Crohn’s disease (CD). The MEDLINE, EMBASE, CINAHL and Cochrane databases were searched for studies on the accuracy of MRI in grading CD compared to a predefined reference standard. Two independent observers scored all relevant data. Three disease stages were defined: remission, mild and frank disease. The accuracy rates of MRI per disease stage were calculated by means of a random-effects model. Seven studies were included from a search resulting in 253 articles. In total 140 patients (16 patients in remission, 29 with mild disease and 95 with frank disease) were used for data analysis. MRI correctly graded 91% (95% CI: 84–96%) of patients with frank disease, 62% (95% CI: 44–79) of patients with mild disease and 62% (95% CI: 38–84) of patients in remission. MRI more often overstaged than understaged disease activity; MRI overstaged disease activity in 38% of patients in remission, mostly as mild disease. Overstaging of mild disease was observed in 21%, understaging in 17%. MRI correctly grades disease activity in a large proportion of patients with frank disease. For patients in remission or with mild disease, MRI correctly stages disease activity in many patients (62%).     

Hydro-MRI in Crohn's disease: appraisal of disease activity

RATIONALE AND OBJECTIVES: To appraise the value of hydro-MRI in the assessment of activity in Crohn's disease. METHODS: After bowel opacification with 1000 mL of an orally administered 2.5% mannitol solution was achieved, axial and coronal breath-hold sequences (T2-weighted half-Fourier acquisition single-shot turbo spin-echo sequences with or without fat saturation, dynamic T1-weighted fast low-angle shot sequences, and contrast-enhanced T1-weighted fast low-angle shot with fat saturation sequences) were acquired in 82 patients with proved Crohn's disease at 1.0 T. Enhancement of the bowel wall was correlated with other MRI findings, with the Crohn's disease activity index (CDAI), and with levels of C-reactive protein (CRP). RESULTS: In Crohn's disease, contrast enhancement of the affected bowel wall was markedly increased in comparison with the normal bowel wall (+80% +/- 22% versus +43% +/- 12%; P = 3 x 10(-15)). Positive correlations could be established between the increase in bowel wall enhancement and many other MRI findings. Between the increase in bowel wall enhancement and the CDAI, only a poor correlation was found (r = 0.25, P = 0.02). There was no statistical correlation between the increase in bowel wall enhancement and CRP. CONCLUSIONS: Hydro-MRI seems to be superior to the CDAI and CRP for the registration of Crohn's disease activity. In particular, differentiation between an active and an inactive (scarred) stenosis, which is crucial for the choice of therapeutic procedures, seems to be more reliable by the interpretation of several morphological and functional parameters on hydro-MRI than by the use of CDAI and CRP.     

Small bowel hydro‐MR imaging for optimized ileocecal distension in Crohn's disease: Should an additional rectal enema filling be performed?

PURPOSE: To assess the impact of an additional rectal enema filling in small bowel hydro-MRI in patients with Crohn's disease. MATERIALS AND METHODS: A total of 40 patients with known Crohn's disease were analyzed retrospectively: 20 patients only ingested an oral contrast agent (group A), the other 20 subjects obtained an additional rectal water enema (group B). For small bowel distension, a solution containing 0.2% locust bean gum (LBG) and 2.5% mannitol was used. In all patients, a breathhold contrast-enhanced T1w three-dimensional volumetric interpolated breathhold examination (VIBE) sequence was acquired. Comparative analysis was based on image quality and bowel distension as well as signal-to-noise ratio (SNR) measurements. MR findings were compared with those of conventional colonoscopy, as available (N = 25). RESULTS: The terminal ileum and rectum showed a significantly higher distension following the rectal administration of water. Furthermore, fewer artifacts were seen within group B. This resulted in a higher reader confidence for the diagnosis of bowel disease, not only in the colon, but also in the ileocecal region. Diagnostic accuracy in diagnosing inflammation of the terminal ileum was 100% in group B; in the nonenema group there were three false-negative diagnoses of terminal ileitis. CONCLUSION: Our data show that the additional administration of a rectal enema is useful in small bowel MRI for the visualization of the terminal ileum. The additional time needed for the enema administration was minimal, and small and large bowel pathologies could be diagnosed with high accuracy. Thus, we suggest that a rectal enema in small bowel MR imaging be considered.     

Feasibility of evaluating Crohn's disease activity at 3.0 Tesla

PURPOSE: To determine whether abdominal 3.0T MRI can be used for evaluation of Crohn's disease (CD) compared with ileocolonoscopy (CS), and to determine patient preference for MRI as opposed to CS. MATERIALS AND METHODS: Twenty patients scheduled for CS underwent MRI. At CS, disease severity was graded and the Crohn's Disease Endoscopic Index of Severity (CDEIS) was determined. Radiological grading (by two observers) was compared with endoscopic grading and CDEIS. Patient experience and preference were determined. RESULTS: In respectively 10 (observer 1) and 13 patients (observer 2) exact agreement between radiological and endoscopic grading was found. In respectively 10 and 7 patients radiological and endoscopic grading differed one level. No statistically significant correlation was found between radiological grading and CDEIS. Between bowel wall thickness and CDEIS weak to moderate correlations were found, and between bowel wall enhancement and CDEIS weak correlations were found. All patients preferred MRI over CS. CONCLUSION: It is feasible to perform abdominal 3.0T MRI using orally administered contrast medium for evaluation of CD, and this method can be considered a patient-friendly alternative to CS.     

Imaging of small bowel Crohn's disease: can abdominal CT replace barium radiography?

Objectives: To analyze imaging features and compare the diagnostic information provided by abdominal computed tomography (CT) and enteroclysis to see whether CT can replace barium examinations in the assessment of patients with small bowel Crohn's disease. Methods: The abdominal CT studies and enteroclysis of 33 patients with small bowel Crohn's disease who underwent both examinations within a 2-week time period were retrospectively reviewed and scored for the presence and severity of the following features: mural edema, ulceration, small bowel obstruction, stricture, sinus tract formation, fistula, abscess, extraintestinal manifestations, and total number of intestinal sites involved. The statistical significance of the differences for each variable was calculated. Results: A total of 37 case sets were reviewed. CT demonstrated 10 (27 %) abscesses compared to 7 (19 %) shown by enteroclysis. Three extraintestinal sites shown by CT were not demonstrated by enteroclysis. Enteroclysis detected a larger number of intestinal sites of involvement (54 vs. 47) and more cases of ulceration (78 % vs. 19 %), small bowel obstruction (46 % vs. 16 %), stricture (38 % vs. 11 %), fistula formation (24 % vs. 8 %), and sinus tract formation (27 % vs. 5 %). The two modalities were similar in characterizing and grading the severity of mural thickening (CT showed 41 %, enteroclysis 46 %). Conclusion: Abdominal CT and enteroclysis provide unique and complementary diagnostic information in patients with Crohn's disease of the small bowel. Both methods may be required for the accurate assessment of the severity and extent of Crohn's disease of the small bowel. The choice of initial examination will depend on the clinical issue in question.     

MR imaging evaluation of the activity of Crohn's disease.

OBJECTIVE: The purpose of this study was to evaluate the sensitivity and specificity of MR imaging in assessing the activity of Crohn's disease. SUBJECTS AND METHODS: Thirty symptomatic patients with Crohn's disease but uncertain disease activity were prospectively examined using MR imaging. Twenty-nine patients were scored using the Crohn's disease activity index. Six hundred milliliters of water orally and 1 mg of glucagon intramuscularly were given before imaging. Breath-hold images were obtained using T2-weighted turbo spin-echo, T1-weighted fast low-angle shot, and fat-suppressed gadolinium-enhanced T1-weighted fast low-angle shot sequences. Images were assessed by two radiologists who were unaware of the patient's symptoms, clinical scoring, and other imaging tests, and who reached a consensus about the imaging findings (bowel wall thickening, bowel wall enhancement, and perienteric changes) and determined the absence or presence of active disease in each patient. MR imaging findings were correlated with endoscopy and surgery. RESULTS: Twenty-three patients had active disease and seven patients had inactive disease. One hundred twenty-four of a total of 168 bowel segments were examined with both MR imaging and endoscopy or surgery. On a per patient basis, MR imaging had an overall sensitivity of 91% and a specificity of 71% for active disease. The Crohn's disease activity index had a sensitivity of 92% and a specificity of 28%. On a per segment basis, MR imaging had a sensitivity of 59% and a specificity of 93%. Bowel wall thickening of greater than 4 mm, bowel wall enhancement (ratio of signal intensity of abnormal to normal bowel > 1.3:1), and increased mesenteric vascularity were useful in identifying active disease. A layered enhancement pattern after the IV administration of gadolinium was highly specific for active inflammation. CONCLUSION: MR imaging is useful in assessing the activity of Crohn's disease and may be helpful when clinical scoring is equivocal.     

A prospective randomized comparison between two MRI studies of the small bowel in Crohn’s disease,the oral contrast method and MR enteroclysis

The aim was to compare bowel distension and diagnostic properties of magnetic resonance imaging of the small bowel with oral contrast (MRI per OS) with magnetic resonance enteroclysis (MRE). Forty patients with suspected Crohn’s disease (CD) were examined with both MRI methods. MRI per OS was performed with a 6% mannitol solution and MRE with nasojejunal intubation and a polyethylenglycol solution. MRI protocol consisted of balanced fast field echo (B-FFE), T2 and T1 sequences with and without gadolinium. Two experienced radiologists individually evaluated bowel distension and pathological findings including wall thickness (BWT), contrast enhancement (BWE), ulcer (BWU), stenosis (BWS) and edema (EDM). The diameter of the small bowel was smaller with MRI per OS than with MRE (difference jejunum: 0.55 cm, p < 0.001; ileum: 0.35 cm, p < 0.001, terminal ileum: 0.09 cm, p = 0.08). However, CD was diagnosed with high diagnostic accuracy (sensitivity, specificity, positive and negative predictive values: MRI per OS 88%, 89%, 89%, 89%; MRE 88%, 84%, 82%, 89%) and inter-observer agreement (MRI per OS k = 0.95; MRE k = 1). In conclusion, bowel distension was inferior in MRI per OS compared to MRE. However, both methods diagnosed CD with a high diagnostic accuracy and reproducibility.     

Crohn’s disease: Activity,complications and treatment. Evaluation using MDCT enterography and endoscopy

Activity of small bowel inflammatory disease, mainly Crohn’s disease had traditionally been a challenging task for radiologists and gastroenterologists. Conventional radiologic and endoscopic evaluations are frequently hindered by the length and caliber of small bowel loops. Conventional CT plays a significant role in the evaluation of extraenteric manifestations of small bowel disease, although it has a limited role for depicting bowel wall and luminal abnormalities. With the development of CT enterography, evolving new methods for evaluating the small bowel mucosal and submucosal abnormality were considered a byproduct of the recent advances in multidetector-row CT (MDCT) technology. Endoscopic correlation with imaging modalities are complementary tools for the final diagnosis of activity and complications of Crohn’s disease.     

Comparison of sonographically measured bowel wall vascularity, histology, and disease activity in Crohn’s disease

The purposes of this study was to provide a retrospective comparison of semiquantitatively measured bowel wall vascularity by power Doppler sonography, endoscopic-histopathological biopsy findings, and disease activity in patients with confirmed Crohn’s disease. Thirty-two out of 1,332 patients with histologically confirmed Crohn’s disease (18 female, 14 male; mean age 38.8 years) met the inclusion criteria: ileocolonoscopy with biopsy and power Doppler sonographic determination of bowel wall vascularity with assessment of disease activity within a period of 5 days. Sonographic determination of bowel wall vascularity was based on a semiquantitative score. Endoscopic bowel wall biopsy specimens were assessed using a self-developed inflammation score and the disease activity was calculated using Crohn’s disease activity index (CDAI). A significant association (p < 0.05) was shown for results of histology and bowel wall vascularity in the terminal ileum (κ = 0.66; sensitivity 95%; specificity 69%). There was no observed association between CDAI and histology, although there was an association between CDAI and bowel wall vascularity (sensitivity 82%). Increased bowel wall vascularity in the terminal ileum measured by power Doppler ultrasound reflects inflammatory activity in histologically examined bowel wall. Power Doppler ultrasound may be able to monitor activity changes of the bowel wall determined by pharmaceutical treatment. B. H. Drews and T. F. E. Barth contributed equally.     

Breathhold MRI of the small bowel in Crohn's disease after enteroklysis with oral magnetic particles

Purpose: To evaluate the efficacy of breathhold MRI following enteroclysis with addition of oral magnetic particles to study the extension, detection of stenoses and extraluminal manifestations in Crohn's disease. Material and Methods: 18 patients with Crohn's disease and potential of surgical intervention were studied with enteroclysis with addition of oral magnetic particles. T1-/T2-weighted breathhold MRI w/o spectral fat suppression w/o i. v. Gd-DTPA was applied. Results: Typical findings were marked bowel wall thickening with strong contrast enhancement. 95.8 % of affected small bowel segments and 94.7 % of stenoses were correctly detected by MRI. All four fistulas were detected and important extraluminal findings were seen in 6/18 patients. Additionally, one ileoileal and two ileosigmoidal adhesions, two extraluminal abscesses and affection of the right ureter were delineated. Conclusion: MRI in Crohn's disease offers the potential to avoid radiation exposure in this relatively young patient group. Important additional findings relevant to indication of surgery are seen in approximately one third of cases. The replacement of transduodenal intubation by oral contrast application remains to be further studied.      

Role of spectral presaturation attenuated inversion-recovery fat-suppressed T2-weighted MR imaging in active inflammatory bowel disease

Purpose

To retrospectively evaluate the efficacy of spectral presaturation attenuated inversion‐recovery (SPAIR) fat‐suppressed (FS) partial Fourier single shot (SSH) T2‐weighted (T2W) and gadolinium‐enhanced (Gd) FS 3D‐gradient echo (3DGRE) T1‐weighted (T1W) delayed phase MRI to differentiate active bowel inflammation from fibrotic disease in patients with Crohn's disease (CD).

Materials and Methods

MRI studies of 81 patients (mean age, 43 years; range, 22–77 years; M:F ratio 33:48) had T2W and T1W imaging including SPAIR‐SSH and delayed Gd‐3DGRE. The ability to assess disease activity in bowel segments affected were retrospectively evaluated by a grading scheme based on subjective analysis of signal intensities. These results were compared against the standard clinical parameters of disease activity.

Results

SPAIR‐SSH images correlated better (r = 0.74, P < 0.0001) with activity than delayed Gd‐3DGRE (r = 0.39, P = 0.0003), with a significant difference between the two techniques (P < 0.0001). SPAIR‐SSH images showed higher specificity in detection of severely active disease in per patient (98%) and segmental (98%) analysis compared to Gd‐3DGRE (57%, 70%). Gd‐3DGRE technique showed significantly higher sensitivity (P = 0.01) in identifying active disease in per patient (83%) and segmental (85%) analysis compared to SPAIR‐SSH (70%, 64%).

Conclusion

SPAIR‐SSH detects actively diseased CD bowel segments with a high level of specificity. Noninflammatory bowel fibrosis corresponds to abnormal uptake on delayed phase Gd‐3DGRE images but without associated elevated abnormal signal on SPAIR‐SSH. J. Magn. Reson. Imaging 2008;28:1133–1140. © 2008 Wiley‐Liss, Inc.     

Technetium-99m hexamethyl propylene amine oxine leucocytes in the assessment of disease activity in inflammatory bowel disease

The inflammatory activity in 108 bowel segments of 40 patients with suspected or known inflammatory bowel disease was assessed macroscopically by endoscopy, histology and technetium-99m hexamethyl propylene amine oxine (^99mTc-HMPAO) leucocytes using a numerical grading system (scores 0–3). A 4-h series of scintigrams showed a significant correlation with both histological and macroscopical assessment of disease activity (rho = 0.850, P<0.001 and rho = 0.773, P<0.001, respectively). Sensitivity, specificity and accuracy of scintigraphy in detecting active inflammatory segments were 85%, 92% and 89%, respectively. A normal scintigram did not completely exclude mild inflammatory activity, especially in the rectosigmoid area. ^99mTc-HMPAO leucocytes offer an accurate and non-invasive alternative for the assessment of disease activity in ulcerative colitis and Crohn's disease. Offprint requests to: E. Lantto     

CT of prominent pericolic or perienteric vasculature in patients with Crohn's disease: correlation with clinical disease activity and findings on barium studies

OBJECTIVE. The purpose of this study was to correlate CT findings of prominent pericolic or perienteric vasculature with clinical disease activity, treatment methods, and barium enema study findings in patients with Crohn's disease. MATERIALS AND METHODS: We retrospectively analyzed 33 patients with Crohn's disease who had undergone both barium enema study and abdominal CT. CT scans were evaluated for the presence and location of prominent vasculature. On the basis of the Crohn's disease activity index, the patients were assigned to one of three categories--active, intermediate, or quiescent disease groups--and the frequency of prominent vasculature was compared among them. Thereafter, erythrocyte sedimentation rates, C-reactive protein levels, treatment methods, and radiographic findings were compared in groups with and without prominent vasculature. RESULTS: Prominent vasculature was more frequently found in patients with active disease (81%) than in those with intermediate (33%) and quiescent disease (0%) (p < 0.001). The erythrocyte sedimentation rates and C-reactive protein levels were higher in patients with prominent vasculature (but not at a statistically significant rate). Patients with prominent vasculature were more frequently admitted to the hospital (p = 0.024) and received more aggressive treatment (p = 0.049) than patients without prominent vasculature. The main differences of radiographic findings between the group with prominent vasculature and the group without prominent vasculature included the common occurrence of longitudinal and perpendicular ulceration (p = 0.017 for small bowel; p = 0.041 for colon) and the extensive length of organ involvement (p = 0.004 for small bowel; p = 0.036 for colon). CONCLUSION: Prominent pericolic or perienteric vasculature seen on CT in patients with Crohn's disease suggests that the disease is clinically active, advanced, and extensive and that these patients require more aggressive treatment than patients without this CT finding.     

CT在克隆氏病诊断中的应用

目的:评价CT在克隆氏病诊断中的价值。方法:对14例经病理证实的克隆氏病的CT表现进行回顾性分析。结果:所有病例均可见肠壁环形或不规则增厚、肠腔变形、狭窄。6例伴小肠梗阻;2例伴回肠末段不规则炎性肿块;2例见瘘管形成。结论:CT可提供克隆氏病的小肠梗阻平面,病变的范围及并发症等信息。     

X线、CT和MRI对小肠Crohn病诊断价值的评价

目的:探讨X线、CT和MRI对小肠Crohn病的诊断价值及其限度.材料和方法:分析经肠镜、手术和病理诊断的26例小肠Crohn病的X线、CT和MRI表现,其中X线小肠灌肠13例,CT小肠造影15例,MRI检查13例(其中小肠MRI水成像和注气小肠灌肠分别为7例和6例),同时行X线小肠灌肠和CT检查7例,行X线小肠灌肠和MRI检查8例,行CT和MRI检查2例.结果:13例小肠Crohn病的X线表现为多个节段性病变12例(92%),线形溃疡11例(85%),卵石征11例(85%),瘘管形成4例,不对称性病变伴假憩室样改变3例,误诊为肠管外炎性肿块和脓肿3例.15例CT小肠造影表现为肠壁增厚15例(100%),强化增加13例(87%),多节段性病变13例(87%),肠管周围蜂窝织炎11例(73%),脓肿和炎性肿块5例,瘘管形成3例.13例MRI表现为肠壁强化增加13例(100%),肠壁增厚12例(92%),多节段性病变11例(85%),肠管周围蜂窝织炎9例(69%),炎性肿块6例,瘘管2例.CT和MRI均未显示肠壁线形溃疡和卵石征.结论:X线小肠灌肠易于显示小肠Crohn病线形溃疡和卵石征的特征性改变,对小肠Crohn病的初次诊断具有重要价值,但难以明确显示肠管外炎性肿块和脓肿;CT和MRI均难以显示肠壁线形溃疡和卵石征,但可明确显示病变肠壁及其周围并发症,对于指导临床治疗以及评价临床疗效具有重要价值.