Small-Bowel Crohn Disease Treated With Anti-Tumor Necrosis Factor-α Therapy: MR Enterography Score Changes After 1 Year Predict Long-Term Outcomes.

OBJECTIVE. The purpose of this article is to assess the ability of MR enterography (MRE) to predict the evolution of Crohn disease (CD) under anti-tumor necrosis factor-α (anti-TNF) therapy. In particular, we analyzed the effect of achieving a radiologic response (RR) on long-term patient outcomes. MATERIALS AND METHODS. We included patients with small-bowel CD who successfully started receiving anti-TNF (infliximab or adalimumab) therapy and achieved clinical remission between 2008 and 2015. MRE was performed at baseline and close to 1 year after treatment initiation. The degree of CD activity was evaluated on the basis of a per-patient MRE score used at our hospital. Individual scores were calculated and recorded on the day of analysis. The median duration of follow-up after induction therapy was 5 years (interquartile range, 2.5-9.0 years). Cumulative probabilities of not having a loss of response (LOR) were assessed using the Kaplan-Meier method and compared using the log-rank test. RESULTS. Thirty-four patients fulfilled the prerequisites for inclusion in the study. Complete RR was achieved in nine patients (26.5%), partial RR in 13 (38.2%), and either no RR or worsening in 12 (35.3%). For the three aforementioned response groups, the estimated probability of absence of LOR at 5 years was 0.88, 0.69, and 0.25, respectively, and the log-rank test suggested that the risk rates for LOR were different (p = 0.023). Based on Cox regression, an MRE score reduction of less than 50% at close to 1 year after treatment initiation was an independent risk factor for LOR (hazard ratio, 0.257; 95% CI, 0.070-0.953; p = 0.027). CONCLUSION. The MRE response after 1 year is a predictor of the efficacy of anti-TNF treatment.

Role of magnetic resonance imaging in the management of perianal Crohn's disease.

Perianal fistulas are a major problem in many patients with Crohn's disease. These are usually complex fistulas that adversely affect patients' quality of life, and their clinical management is difficult. Medical treatment sometimes achieves cessation of discharge and closure of the external opening; however, it is difficult to assess the status of the rest of the fistula tract. Magnetic resonance imaging is the method of choice with which to evaluate the condition of perianal fistulas and allows for assessment of the status of inaccessible areas. Magnetic resonance imaging also allows the clinician to evaluate other perianal manifestations of Crohn's disease that differ from the fistulas. This imaging technique is therefore a fundamental means of patient monitoring. When used in conjunction with assessment of the patient's morphological findings, it provides information that allows for both quantification of disease severity and evaluation of the response to treatment. New types of magnetic resonance sequences are emerging, such as diffusion, perfusion, and magnetisation transfer. These sequences may serve as biomarkers because they provide information reflecting the changes taking place at the molecular level. This will help to shape a new scenario in the early assessment of the response to treatments such as anti-tumour necrosis factor drugs. TEACHING POINTS: • MRI is the method of choice with which to evaluate perianal fistulas. • In perianal Crohn's disease, MRI is a fundamental means of patient monitoring. • The usefulness of the Van Assche score for patient monitoring remains unclear. • New MRI sequences' diffusion, perfusion, and magnetisation transfer may serve as biomarkers.

Is there a role of magnetic resonance imaging in deciding to stop anti-tumor necrosis factor treatment in ileal Crohn's disease?

PURPOSE: This study was performed to assess the ability of magnetic resonance enterography to predict the evolution of patients in whom anti-tumor necrosis factor-α therapy was suspended. METHODS: A prospective study of patients with ileal Crohn's disease was performed. RESULTS: Twenty-nine patients were included. Patients who later relapsed showed higher magnetic resonance scores than those who did not relapse (4.2 vs. 2.5, respectively; p<0.02). The area under the receiving-operating characteristics curve was 0.755 when discriminating patients who relapsed. CONCLUSIONS: Magnetic resonance enterography should be taken into account when deciding the withdrawal of anti-tumor necrosis factor-α in patients with Crohn's disease.

Evaluation of myometrial invasion in endometrial cancer: comparison of diffusion-weighted magnetic resonance and intraoperative frozen sections.

OBJECTIVE: To compare the diagnostic accuracy of diffusion-weighted magnetic resonance imaging (DWI) and frozen-section analysis in assessing myometrial invasion in endometrial cancer to guide surgery. METHODS: In this prospective study, 51 women with diagnosed endometrial cancer were examined using magnetic resonance imaging (MRI) and subsequently underwent hysterectomy with intraoperative frozen-section assessment. The MRI protocol included T2-weighted images (T2WI), a dynamic T1-weighted post-gadolinium series, and DWI sequences acquired with b values of 0, 150, and 800 s/mm(2). Apparent diffusion coefficient (ADC) maps were obtained in all the studies. Deep myometrial invasion was defined as involvement of ≥50% of the thickness of the myometrium. The final postoperative pathological evaluation was considered as the reference standard. RESULTS: The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of DWI for detecting deep invasion of the myometrium were 90.2%, 77.8%, 97%, 93.3%, and 88.9%, respectively. For the intraoperative frozen section, these figures were 90.2%, 73.7%, 100%, 100%, and 86.5%. The precision for both tests was the same using McNemar's test (p = 1). CONCLUSION: In assessing the depth of myometrial invasion, ADC maps show the same accuracy as intraoperative histological studies in endometrial cancers. They also allow for a more precise assessment than conventional MRI sequences. Frozen-section analysis can be avoided if the preoperative MRI study includes DWI sequences and ADC maps.

Ileal Crohn's disease: MRI with endoscopic correlation.

PURPOSE: To evaluate activity staging of Crohn's disease (CD) measured with MR-enterography using ileoscopy as reference standard. MATERIALS AND METHODS: A prospective study was made of 61 patients with CD. All patients underwent MR-enterography and ileoscopy. MRI activity was measured by means of an ad hoc developed score, as well as by analysis of the imaging findings, and was compared with the SES-CD score obtained via ileoscopy. Examinations were performed using a 1.0 T scanner. RESULTS: MRI score discriminates between active and inactive disease with an area under the ROC curve of 0.941. Overall correlation with the standard reference SES-CD score was moderate to strong (Spearman's r=0.62 p<0.001). Agreement between both methods in staging patients with ileal CD as inactive, mild or moderate to severe was good (Cohen's κ=0.60). Differences in means of the MRI activity scores of the three groups showed statistical significance (p<0.01). CONCLUSIONS: The MRI score is a reliable predictor of activity in ileal CD and can stage patients in a way comparable to endoscopy. 1.0 T scans are valid for performing radiological evaluation of ileal Crohn's disease.