Magnetic Resonance Colonography for the Detection of Colorectal Neoplasia in Asymptomatic Adults
Menée sur 286 patients adultes âgés de 40 à 82 ans, cette étude évalue, par rapport à un test immunochimique de recherche de sang occulte dans les selles, la sensibilité et la spécificité d'une colonographie par résonance magnétique pour détecter précocement une néoplasie colorectale asymptomatique
Colonoscopy is the preferred screening test for colorectal neoplasia; the fecal occult blood test (FOBT) detects neoplasias with low levels of sensitivity. Computed tomography colonography detects neoplasias with high levels of sensitivity, but involves exposure to radiation. We investigated whether magnetic resonance colonography (MRC) can be used to screen for colorectal adenomas and cancers. We analyzed data from 286 asymptomatic adults (40–82 years old) who underwent 3 Tesla MRC and colonoscopy examinations on the same day. The FOBT was performed before bowel preparation. Colonoscopists were initially blinded to MRC findings and unblinded after withdrawal from the respective segments. Sensitivities for adenoma and per patient sensitivities and specificities were calculated based on the unblinded colonoscopy results. We detected 133 adenomas and 2 cancers in 86 patients; 37 adenomas were ≥6 mm and 20 adenomas were advanced. Sensitivities of MRC and colonoscopy for adenoma ≥6 mm were 78.4% (95% confidence interval [CI], 61.8-90.2) and 97.3% (95% CI, 85.8–99.9); for advanced adenomas, these values were 75% (95% CI, 50.9-91.3) and 100% (95% CI, 83.2–100.0), respectively. MRC identified 87.1% (95% CI, 70.2-96.4), colonoscopy 96.8% (95% CI, 83.3–99.9), and FOBT 10.0% (95% CI, 2.1-26.5) of individuals with adenoma ≥6 mm, and 83.8% (95% CI, 58.6–96.4), 100% (95% CI, 81.5-100.0), and 17.6% (95% CI, 3.8–43.4) of individuals with advanced neoplasia. Specificities of MRC, colonoscopy, and the FOBT for individuals with adenoma ≥6 mm were 95.3% (95% CI, 91.9-97.5), 96.9% (95% CI, 93.9–98.6), and 91.8% (95% CI, 87.6-94.9), respectively. 3 Tesla MRC detects colorectal adenomas ≥6 mm and advanced neoplasias with high levels of sensitivity and specificity. Although MRC detects colorectal neoplasias with lower levels of sensitivity than colonoscopy, it strongly outperforms one-time FOBT.
Gastroenterology , résumé, 2012