Abstract:Objective: To evaluate the value of ultrasound (US) combined with magnetic resonance imaging (MRI) in diagnosing fetal chest and abdomen abnormalities. To propose and discuss the clinical significance of structural malformation score (SMS) based on chromosome examination results. Methods: A retrospective study was conducted on 77 fetuses who were examined by US and MRI from March 2016 to September 2019 and met the inclusion criteria. The indications of US combined with MRI were discussed, and the sensitivity, specificity, positive predictive value and negative predictive value of ultrasound, MRI and ultrasound combined with MRI were calculated. The receiver operating characteristics (ROC) curve was used to analyze the value of ultrasound and MRI physicians in the diagnosis of fetal chest and abdomen abnormalities. According to the chromosome results, the SMS for the chest and abdomen of the fetus was determined by the percentage of chromosomal positive cases. Results: ①The limitation of ultrasound application was the main reason for increasing MRI examination.②Follow-up of 77 pregnant women showed normal (negative) fetuses in 27 cases (35.1%) and abnormal (positive) fetuses in 50 cases (64.9%), 25 cases (32.5%) were negative and 52 cases (67.5%) were positive for US, and 28 cases (36.4%) were negative and 49 cases (63.6%) were positive for MRI. The sensitivity, specificity, positive predictive value, and negative predictive value of US combined with MRI were 96.0%, 92.6%, 96.0%and 92.6%, respectively, which were significantly higher than those of US alone and MRI alone. The area under the ROC curve (AUC) for US diagnosis was 0.792, the AUC for MRI diagnosis was 0.819, and AUC for US combined MRI diagnosis was 0.943. Compared with single US and single MRI, the difference was statistically significant (Z=2.23, P=0.026; Z=1.97, P=0.049). ③According to the calculation of the positive percentage of chromosome, SMS was divided into 5 grades, namely 0≤1 score<25%, 25%≤2 scores<50%, 50%≤3 scores<75%, 75%≤4 scores<100%, and 100%=5 scores. When 4 scores≤SMS<10 scores, clinical chromosome or gene testing was recommended, and when SMS≥10 scores, termination of pregnancy was recommended if clinically necessary. Conclusion: Joint diagnosis of ultrasound and MRI has the highest comprehensive diagnosing efficiency, and precise diagnosis and accurate assessment scoring play an important role in guiding clinical decision-making.
