Department of Gastroenterology and Clinical Nutrition Service, Royal Melbourne Hospital, Grattan Street, Parkville, VIC 3052, Australia.
Fam Cancer. 2010 Dec;9(4):555-61. doi: 10.1007/s10689-010-9350-9.
Lynch syndrome gene carriers have a 50-80% risk of colorectal cancer (CRC). Current guidelines recommend yearly colonoscopy, with associated procedure-related risks. Magnetic resonance colonography (MRC) was evaluated as a non-invasive alternative for CRC screening in this high-risk population. Adult Lynch syndrome gene carriers underwent both screening procedures on the same day. MRI radiologists read the scans and rated image quality. Endoscopists performed colonoscopy unaware of MRC findings until after procedure completion. If lesions were detected, their number, size and location were noted. Post-procedure, patients compared discomfort and inconvenience of MRC and colonoscopy on a visual analogue scale. Thirty patients were recruited. 83% of the MRC scans were of adequate to good quality. MRC detected three lesions in three patients (70, 36, 17 mm). All 3 were independently detected on colonoscopy, excised and found to be CRC. MRC failed to detect a 3 mm CRC found on colonoscopy. CRC prevalence was 13%. Colonoscopy detected a further 30 polyps, all <10 mm. Of these, 17 were hyperplastic polyps and 10 normal mucosa. Colonoscopy had a false positive rate of 32% as defined by histology. MRC failed to detect any polyp <10 mm. Mean patient discomfort scores were 20% for MRC and 68% for colonoscopy, P = 0.003. Mean patient inconvenience scores were 54% for MRC and 52% for colonoscopy, P = 0.931. MRC was reliable in detecting large polyps, potentially CRC. However MRC currently has poor sensitivity in detecting small polyps, limiting its utility in adenoma screening at this time. MRC was associated with less discomfort than CC.
林奇综合征基因携带者患结直肠癌（CRC）的风险为 50-80%。目前的指南建议每年进行结肠镜检查，同时存在与操作相关的风险。磁共振结肠成像（MRC）被评估为该高危人群 CRC 筛查的非侵入性替代方法。成年林奇综合征基因携带者在同一天接受这两种筛查程序。磁共振成像放射科医生阅读扫描结果并对图像质量进行评分。内窥镜医生在完成检查后才知道 MRC 的检查结果。如果发现病变，记录其数量、大小和位置。检查后，患者使用视觉模拟量表比较 MRC 和结肠镜检查的不适和不便程度。共招募了 30 名患者。83%的 MRC 扫描质量良好。MRC 在 3 名患者中发现了 3 个病变（70、36、17mm）。所有 3 个均在结肠镜下独立发现，切除后均被诊断为 CRC。MRC 未能检测到结肠镜下发现的 3mmCRC。CRC 的患病率为 13%。结肠镜检查还发现了 30 个息肉，均<10mm。其中，17 个为增生性息肉，10 个为正常黏膜。根据组织学定义，结肠镜检查的假阳性率为 32%。MRC 未能检测到任何<10mm 的息肉。MRC 的平均患者不适评分是 20%，结肠镜检查的平均患者不适评分是 68%，P=0.003。MRC 的平均患者不便评分是 54%，结肠镜检查的平均患者不便评分是 52%，P=0.931。MRC 可可靠地检测到大息肉，包括潜在的 CRC。然而，MRC 目前在检测小息肉方面的敏感性较差，因此在现阶段限制了其在腺瘤筛查中的应用。MRC 比 CC 引起的不适更少。
