Diagnostic accuracy of ultrasonography and magnetic resonance imaging for the detection of fetal anomalies: a blinded caseâ control study

摘要

ObjectivesTo compare the accuracy of twoâ dimensional ultrasound (2Dâ US), threeâ dimensional ultrasound (3Dâ US) and magnetic resonance imaging (MRI) for the diagnosis of congenital anomalies without prior knowledge of indications and previous imaging findings.MethodsThis was a prospective, blinded caseâ control study comprising women with a singleton pregnancy with fetal congenital abnormalities identified on clinical ultrasound and those with an uncomplicated pregnancy. All women volunteered to undergo 2Dâ US, 3Dâ US and MRI, which were performed at one institution. Different examiners at a collaborating institution performed image interpretation. Sensitivity and specificity of the three imaging methods were calculated for individual anomalies, based on postnatal imaging and/or autopsy as the definitive diagnosis. Diagnostic confidence was graded on a fourâ point Likert scale.ResultsA total of 157 singleton pregnancies were enrolled, however nine cases were excluded owing to incomplete outcome, resulting in 148 fetuses (58 cases and 90 controls) included in the final analysis. Among cases, 13 (22.4%) had central nervous system (CNS) anomalies, 40 (69.0%) had nonâ CNS anomalies and five (8.6%) had both CNS and nonâ CNS anomalies. The main findings were: (1) MRI was more sensitive than 3Dâ US for diagnosing CNS anomalies (MRI, 88.9% (16/18) vs 3Dâ US, 66.7% (12/18) vs 2Dâ US, 72.2% (13/18); McNemar’s test for MRI vs 3Dâ US: Pâ =â 0.046); (2) MRI provided additional information affecting prognosis and/or counseling in 22.2% (4/18) of fetuses with CNS anomalies; (3) 2Dâ US, 3Dâ US and MRI had similar sensitivity for diagnosing nonâ CNS anomalies; (4) specificity for all anomalies was highest for 3Dâ US (MRI, 85.6% (77/90) vs 3Dâ US, 94.4% (85/90) vs 2Dâ US, 92.2% (83/90); McNemar’s test for MRI vs 3Dâ US: Pâ =â 0.03); and (5) the confidence of MRI for ruling out certain CNS abnormalities (usually questionable for cortical dysplasias or hemorrhage) that were not confirmed after delivery was lower than it was for 2Dâ US and 3Dâ US.ConclusionsMRI was more sensitive than ultrasonography and provided additional information that changed prognosis, counseling or management in 22.2% of fetuses with CNS anomalies. Falseâ positive diagnoses for subtle CNS findings were higher with MRI than with ultrasonography. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.