Radiology Dea Department, Umberto I Hospital, Sapienza University, Viale del Policlinico 155, 00161 Rome, Italy.
Eur Radiol. 2011 Sep;21(9):1841-9. doi: 10.1007/s00330-011-2120-8. Epub 2011 Apr 12.
To compare the accuracy of magnetic resonance (MRI) and colour Doppler-ultrasound (US) in the diagnosis of late pregnancy bleeding and to assess the accuracy of the different MR sequences in visualizing the origin of haemorrhage.
42 patients in the third trimester of pregnancy underwent to US and MRI for the evaluation of painless vaginal bleeding. Multiplanar HASTE, True Fisp, 3D T1 GRE and sagittal DWI sequences were acquired. Two radiologists, blinded to the results of US, reviewed each case, resolving by consensus any discrepancy. Reference standards were surgical and pathological findings.
The reference standards identified 22 placenta previa, 11 placental abruptions (1 coincident with a placental chorioangioma), 1 thrombohaematoma and 1 fibroma with haemorrhagic degeneration. MRI identified correctly all these condition with an interobserver agreement of 0.955. DWI and T1 weighted sequences were statistically superior to Haste and True Fisp sequences in detecting the cause of bleeding (p < .001). US had 6 false negatives and 2 false positive results, its diagnostic accuracy resulting lower than MRI (p = .001).
MRI accurately evaluates pregnancy bleeding with an excellent interobserver agreement and can grant new and additional data when US is negative.
比较磁共振（MRI）和彩色多普勒超声（US）在诊断妊娠晚期出血中的准确性，并评估不同 MR 序列在显示出血来源方面的准确性。
对 42 例妊娠晚期因无痛性阴道出血而接受 US 和 MRI 检查的患者进行研究。采集多平面 HASTE、True Fisp、3D T1 GRE 和矢状面 DWI 序列。两位放射科医生在不知道 US 结果的情况下对每个病例进行了评估，通过共识解决了任何差异。参考标准为手术和病理发现。
参考标准确定了 22 例前置胎盘、11 例胎盘早剥（1 例合并胎盘绒毛膜血管瘤）、1 例血栓血肿和 1 例纤维瘤伴出血性变性。MRI 正确识别了所有这些情况，观察者间一致性为 0.955。DWI 和 T1 加权序列在检测出血原因方面明显优于 Haste 和 True Fisp 序列（p<0.001）。US 有 6 个假阴性和 2 个假阳性结果，其诊断准确性低于 MRI（p=0.001）。
MRI 能准确评估妊娠出血，具有极好的观察者间一致性，当 US 结果为阴性时，可提供新的、额外的数据。
