Magnetic resonance enterography predicts the prognosis of Crohn's disease

The Spectrum of Magnetic Resonance Enterography Findings and the Role of Diffusion-Weighted Imaging in Patients with Active Crohn's Disease

Background

The goal of this study was to evaluate magnetic resonance enterography (MRE) findings and assess the role of diffusion-weighted imaging (DWI) in patients suffering from active Crohn's disease.

Methods

This retrospective study included a total number of 76 patients diagnosed with active Crohn's disease, as established by the Crohn's Disease Activity Index (CDAI). The study consisted of 30 women and 46 men, ranging in age from 13 to 72 years. All participants underwent MRE with DWI sequences. The study was conducted at Imam Khomeini hospital in Tehran between 2013 and 2018. The imaging modality utilized for the study included a 3-T SIGNA Excite MRE machine and a Siemens Magnetom 3-T magnetic resonance imaging (MRI) machine.

Results

Bowel wall restriction was observed in less than half of the patients, and no significant correlation was found with extramural findings such as mesenteric edema. The study did not reveal any meaningful association between diffusion restriction and specific mural enhancement patterns, mesenteric lymphadenopathy with or without enhancement, or the length of the affected segments (P>0.05). The most common findings observed in MRI were ileum thickness in 72.4% of patients, mesenteric lymphadenopathy without enhancement in 46.1%, ileocecal thickness in 42.1%, DWI findings in 42.1%, the presence of a comb sign in 36.8%, and jejunum thickness in 30.3% of patients.

Conclusion

MRE findings are useful in the evaluation of Crohn's disease activity.

Distribution of small bowel involvement and its association with clinical outcomes in patients with Crohn's disease

We aimed to evaluate the distribution of small-bowel involvement in Crohn's disease (CD) and its association with clinical outcomes. This study included CD patients who underwent computed tomography (CT) at initial diagnosis from June 2006 to April 2021. Two abdominal radiologists reviewed the CT images, and independently rated the presence of "bowel wall thickening," "stricture," and "fistula or abscess" in the small bowel segments of jejunum, distal jejunum/proximal ileum, distal ileum, and terminal ileum, respectively. Based on findings of the image review, each patient's "disease-extent imaging score" and "behavior-weighted imaging score" (a higher score indicative of more structuring or penetrating disease) were calculated. Major clinical outcomes (emergency department [ED] visit, operation, and use of corticosteroids or biologics) were compared according to the 2 scores and L4 involvement by the Montreal classification. The proportions of involvement in the jejunum, distal jejunum/proximal ileum, distal ileum, and terminal ileum were 2.0%, 30.3%, 82.2%, and 71.7%, respectively, identifying 30.3% of patients as having L4 disease and 69.7% of patients as having involvement of multiple segments. Clinical outcomes were not significantly associated with the disease-extent imaging score or L4 involvement. However, significant differences were noted for the ED visits and the use of biologics, according to the behavior-weighted imaging score. Moreover, in multivariable analysis, disease behavior was the only factor associated with all clinical outcomes (ED visit, hazard ratio [HR] 2.127 [1.356-3.337], P = .001; operation, HR 8.216 [2.629-25.683], P < .001; use of corticosteroid, HR 1.816 [1.249-2.642], P = .002; and use of biologics, HR 2.352 [1.492-3.708], P < .001). Initial disease behavior seems to be a more critical factor for clinical outcomes of CD than the extent or distribution of small-bowel involvement on CT.

MR Enterography in Crohn's Disease: Comparison of Contrast Imaging with Diffusion-weighted Imaging and a special Form of Color Coding

Purpose

We compared contrast-enhanced MR enterography with diffusion-weighted sequences to evaluate the validity of diffusion-weighted sequences for activity assessment in Crohnʼs disease compared to endoscopy. In addition, we investigated a new color-coded image post-processing technique in comparison with standard sequences and endoscopy.

Materials and Methods

Included were 197 MR enterographies (2015–2017) performed by using standardized examination protocols. The intestine was divided into 7 segments, which were compared separately. The accuracy of the MR examinations with regard to disease activity was validated using the Seo and MaRIA score and endoscopy findings. In addition, the image data were post-processed using a color-coded evaluation method (DCE tool on OsiriX).

Results

The comparison between contrast-enhanced and diffusion-weighted sequences showed a highly significant correlation for all bowel sections with a mean Spearman correlation coefficient of 0.876 (0.809–0.928). The color-coded image post-processing showed a sensitivity of 83.2 % and a specificity of 70.5 % in comparison with the MaRIA score. In comparison to endoscopy, a sensitivity of 81.3 % and a specificity of 70.5 %. In comparison with endoscopy, the MaRIA score showed a sensitivity of 80.2 % and a specificity of 84.0 % at a cut-off of 7. The visual score according to Seo showed a sensitivity of 85.7 % with a specificity of 77.0 % in the contrast-weighted examination and a sensitivity of 87.9 % and a specificity of 71.8 % for diffusion weighted images.

Conclusion

Diffusion-weighted sequences are as good as contrast-weighted sequences for assessing inflammatory activity in Crohnʼs disease. Contrast is often helpful for assessing complications, but this was not the purpose of this study. Visual imaging using color-coded data sets was similarly good at detecting inflammation.

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Combined Endoscopic and Radiologic Healing Is Associated With a Better Prognosis Than Endoscopic Healing Only in Patients With Crohn's Disease Receiving Anti-TNF Therapy

INTRODUCTION

Although endoscopic healing (EH) is recommended as the therapeutic goal in patients with Crohn's disease (CD), combined EH and radiologic healing (RH) could be a more ideal therapeutic goal considering the transmural nature of CD. We compared the prognosis of patients with CD who achieved EH, RH, both EH and RH (deep healing; DH), or no healing under treatment with anti-tumor necrosis factor (TNF) agents.

METHODS

We analyzed 392 patients with CD who received anti-TNF treatment for more than 1 year and evaluated with CT enterography or magnetic resonance enterography together with colonoscopy within 3 months between July 2017 and December 2018. Major outcomes (anti-TNF dose intensification, switch to other biologics, CD-related bowel resection, and hospitalization) were compared according to the EH and RH status.

RESULTS

During the follow-up (median 18 months; interquartile range, 15-21), the DH group showed a better rate of major outcome-free survival compared with other groups (P < 0.001). In multivariable analysis, elevated C-reactive protein (adjusted hazard ratio [aHR], 2.166; 95% confidence interval [CI], 1.508-3.110; P < 0.001), EH-only (aHR, 3.903; 95% CI, 1.635-9.315; P = 0.002), RH-only (aHR, 3.843; 95% CI, 1.545-9.558; P = 0.004), and no healing (aHR, 8.844; 95% CI, 4.268-18.323; P < 0.001) were associated with increased risks of major outcomes.

DISCUSSION

Patients with CD who achieved DH under anti-TNF therapy showed a better prognosis compared with those who only achieved EH. The possibility of DH being used as a new therapeutic target for patients with CD should be investigated in further studies.

Crohn's disease at radiological imaging: focus on techniques and intestinal tract

Over recent years, inflammatory bowel diseases have become an issue of increased attention in daily clinical practice, due to both a rising incidence and improved imaging capability in detection. In particular, the diagnosis of Crohn's disease is based on clinical picture, laboratory tests and colonoscopy with biopsy. However, colonoscopic evaluation is limited to the mucosal layer. Thus, imaging modalities play a pivotal role in enriching the clinical picture, delivering information on intestinal and extraintestinal involvement. All the imaging modalities can be employed in evaluation of Crohn's disease patients, each of them with specific strengths as well as limitations. In this wide selection, the choice of a proper diagnostic framework can be challenging for the clinician. Therefore, the aim of this work is to offer an overview of the different imaging techniques, with brief technical details and diagnostic potential related to each intestinal tract.

Radiological Response Is Associated with Better Outcomes and Should Be Considered a Therapeutic Target in Crohn's Disease

BACKGROUND

The aim of the study was to identify factors associated with a radiological response and to assess the impact of radiological improvement in long-term outcomes in small bowel (SB) Crohn's disease (CD) patients.

METHODS

We performed a retrospective study from June 2011 to June 2017 in the tertiary center, Claude Huriez Hospital in Lille, France. All SB CD patients, who underwent two magnetic resonance enterographies (MRE) 3-12 months apart, with at least 1-year follow-up after the second MRE, were included. Signs of radiological inflammation were identified by two expert radiologists in CD. Patients were classified as radiological responders (RR) and non-responders (NR). Hospitalization rates, adjustment of treatment, and surgical or endoscopic interventions were assessed and compared between RR and NR. Factors associated with a radiological response were also studied using the Cox model.

RESULTS

One hundred and fifteen SB CD patients were included with a median follow-up of 17 months (IQR 11.6-28.3). There were 54 (47%) RR and 61 (53%) NR. The risk of surgical or endoscopic intervention was higher in NR than RR (p = 0.04), and the median delay until a surgical or endoscopic intervention was shorter in NR (p = 0.04). Multifocal disease, a hypersignal on diffusion-weighted or dynamic contrast-enhanced imaging, a stricture, or a fistula was significantly associated with a decreased probability of a radiological response (p < 0.05).

CONCLUSION

This study shows that a radiological response is associated with a decreased risk of surgical or endoscopic intervention and should be considered as a therapeutic target in CD patients.

Mucosal healing in Crohn's disease: new insights

INTRODUCTION

Traditional management of patients with Crohn's disease includes symptoms and quality of life improvement. With the advent of biological agents, mucosal healing has become an achievable goal, documented through endoscopy. However, due to the transmural nature of inflammation, the prevention of bowel damage should be included in the aims of a targeted therapeutic strategy.

AREAS COVERED

Updated literature has been searched in PubMed from 2008 to 2020. This review focuses on the state of the art in the innovative therapeutic goals in Crohn's disease, also considering still controversial aspects and future research topics in the management of Crohn's disease.

EXPERT OPINION

Although a widely agreed view supports the notion that mucosal healing and bowel damage control may promote beneficial outcomes (i.e. reduction in hospitalization and surgical rates, avoidance of steroids), long-term robust data are still missing. On the other hand, the development of -omics techniques has expanded our knowledge of the pathogenetic mechanism underlying inflammatory bowel disease and opened up new horizons in precision or personalized medicine.

Magnetic Resonance Enterography and Capsule Endoscopy in Patients Undergoing Patency Capsule for the Evaluation of Small Bowel Crohn's Disease: A Korean Clinical Experience

Objective

Studies comparing magnetic resonance enterography (MRE) and capsule endoscopy (CE) for the assessment of small bowel (SB) Crohn's disease (CD) are scarce in Korea. In addition, there is no Korean experience of patency capsule (PC) examination prior to CE. The primary aim of this study was to compare diagnostic yields of MRE and CE for the assessment of SB CD. Secondary objectives were to compare the detection rate of proximal SB lesions by each modality in the Montreal classification and evaluate the safety and feasibility of PC in Korean CD patients.

Methods

MRE was performed as the first examination to assess SB CD. PC examination and CE were then performed. Diagnostic yields of active SB disease by MRE and CE were then analyzed.

Results

Disintegration of the patency capsule was shown in 5 patients out of 26 patients, who did not undergo CE. These 5 patients were accounted as negative CE findings. Overall, MRE and CE detected 80.8% and 65.4% of active SB lesions of CD in 26 patients, respectively (P = 0.212). MRE and CE detected 0% (0/26) and 19.2% (5/26) (P = 0.051) of jejunal lesions, 30.8% (8/26) and 42.3% (11/26) (P = 0.388) of proximal ileal lesions, and 80.8% (21/26) and 53.8% (14/26) (P = 0.039) of terminal ileal lesions, respectively. According to the Montreal classification, MRE and CE independently detected proximal disease (L4) in 30.8% (8/26) and 53.8% (14/26) (P = 0.092), respectively.

Conclusions

The diagnostic yields of MRE and CE for the assessment of SB CD including proximal SB lesions were similar. MRE is a more objective tool for detecting clinically relevant stricture than PC although PC examination could be performed safely before CE to prove the patency of SB. This trial is registered with KCT0004305.

Changes in the Management of Patients with Crohn's Disease Based on Magnetic Resonance Enterography Patterns

BACKGROUND AND AIMS

Magnetic resonance enterography (MRE) has become an important modality of radiological imaging in the evaluation of Crohn's disease (CD). The aim of this study was to investigate the impact of MRE in the assessment of disease activity and abdominal complications and in the making of therapeutic decisions for patients with CD.

METHODS

In a cross-sectional retrospective study, we selected 74 patients with CD who underwent MRE and ileocolonoscopy with an interval between the two exams of up to 30 days between January 2011 and December 2017. We assessed the parameters of the images obtained by MRE and investigated the agreement with the level of disease activity and complications determined by a clinical evaluation, inflammatory biomarkers, and endoscopy, as well as the resulting changes in medical and surgical management.

RESULTS

Changes in medical management were detected in 41.9% of patients. Significant changes in medical decisions were observed in individuals with a purely penetrating (P = .012) or a mixed (P = .024) MRE pattern. Patients with normal MRE patterns had a correlation with unchanged medical decisions (P = .001). There were statistically significant agreements between the absence of inflammatory criteria on MRE and remission according to the Harvey and Bradshaw index (HBI) (P = .037), the presence of inflammatory criteria on MRE and positive results for calprotectin (P = .005), and penetrating criteria on MRE and the scoring endoscopic system for Crohn's disease (SES-CD), indicating active disease (P = .048). Finally, there was significant agreement between the presence of fibrostenotic criteria and a long disease duration (P = .027).

CONCLUSION

MRE discloses disease activity and complications not apparent with other modalities and results in changes in therapeutic decisions. In addition to being used for diagnosis, MRE should be routinely used in the follow-up of CD patients.