MRI Enterography for the Assessment of Inflammatory Bowel Disease

PICHON RIVIERE, A.; AUGUSTOVSKI, F.; GARCIA MARTI, S.; GLUJOVSKY, D.; ALCARAZ, A.; LOPEZ, A.; REY-ARES, L.; BARDACH, A.; CIAPONI, A; URTASUN, M; SOTO, N

Documento de Evaluación de Tecnologías Sanitarias

IECS

Año: 2013 p. 1 - 30

1668-2793

Inflammatory Bowel Disease (IBD) mainly comprises Ulcerative Colitis (UC) and Chron´s Disease (CD). UC affects the colon and the rectum exclusively, while CD may involve any part of the digestive system. Both conditions present as a chronic inflammatory process of unknown etiology with remission periods, different degrees of severity and potential extra-bowel complications. It is estimated that IBD prevalence may reach 1% of the population and its onset may occur between 18 and 40 years old. Reference diagnostic tests include colonoscopy and histopathology, however there are radiological techniques in growing use mainly for follow up and, sometimes, for diagnosis; they include Computer Tomography (CT) or Magnetic Resonance enterography (MRE).TechnologyMagnetic resonance imaging (MRI) is a radiological technique that makes use of a magnetic field and radiofrequency to generate high-resolution images. MRI allows assessment of the different axis of the abdomen (axial, coronal and sagittal) and visualization of the small bowel wall with luminal details after oral and intravenous contrast administration.PurposeTo assess the available evidence on the efficacy, safety and coverage related aspects regarding the use of MRI enterography for the assessment of inflammatory bowel disease.MethodsA bibliographic search was carried out on the main literature databases: DARE, NHS EED, on Internet general search engines, in health technology evaluation agencies and health sponsors. Priority was given to the inclusion of systematic reviews (SRs); diagnostic usefulness studies, controlled, randomized clinical trials (RCTs); health technology assessments (HTAs) and economic evaluations; clinical practice guidelines (CPGs) and coverage policies of other health systems.ResultsFour systematic reviews (three of them were meta-analyses), four CPGs, two HTAs and two coverage policies were included. The selected studies compared radiological techniques versus colonoscopy and/or histopathology as reference tests.A 68-study SR published in 2011, reported high accuracy for MRE when assessing CD; they presented a 78% sensitivity (95% CI 67-84%) and 85% specificity (95% CI 76- 90%) for CD diagnosis and values over 74% and 80% for sensitivity and specificity respectively, when assessing the inflammatory extent and activity. MRE showed similar values to those of CT, even when identifying complications such as fistulae, abscesses and stenosis.A meta-analysis published in 2008, which included 33 studies with 18 to 440 participants with IBD, estimated a high accuracy for MRE in diagnosis (sensitivity=93%; specificity=92.8%), with no significant differences with the other assessed techniques (Ultrasound testing, CT and scintigraphy).A SR including 11 studies in 496 children, published in 2011, assessed the diagnostic accuracy of MRE in pediatric patients (< 18 years) with IBD. The six-study meta-analysis result showed an 84% summary sensitivity (95% CI 77-90%), a 97% specificity (95% CI 91-99%) and a 0.95 ROC curve.In 2009, a seven-study SR reported that MRE correctly identified inflammatory activity in 91% of the cases with clear inflammatory activity, but only 62% of the cases in remission or with mild inflammatory activity.Four CPG published by European, Hispanic-American and British organizations and societies in2008-2013 and two HTAs published by Spanish agencies between 2008 and 2012 consider that MRE´s diagnostic performance is similar to that of CT in IBD and it would be preferred, if available, because it does not expose the patient to ionizing radiation.Two US, health insurance agencies authorize MRE for CD assessment. One of them has authorized it since 2012 in pregnant women for CD follow up and the other one, authorized it in 2008 depending on the insurance plan.The cost of MRE is +/- 30% higher than CT. According to two Argentine health sponsors, its cost is approximately AR$ 6,000 (Argentine pesos), equivalent to USD 1,130 (American dollars) in June, 2013.ConclusionsThe evidence selected from the SRs and the meta-analysis is of moderate methodological quality. Currently, CT is the most widely used radiological technique both for the diagnosis, when colonoscopy is contraindicated, and for inflammatory activity monitoring in patients with IBD. MRE´s diagnostic performance is similar to that of CT in CD; however, its cost is higher than CT. The CPGs and HTAs also cover the use of MRE mainly as an alternative in CD follow up. There is less evidence supporting the use of UC. MRE´s main advantage is not to expose the patient to ionizing radiation; a limit to its use would be the availability of resonators and/or qualified human resources.