Comparison of the value of transvaginal ultrasonography and MRI in the diagnosis of cesarean scar pregnancy: a meta-analysis

Objective: To compare the diagnostic value of transvaginal ultrasound (TVS) and magnetic resonance imaging (MRI) in cesarean scar pregnancy (CSP) by a method of meta-analysis.

Methods: Studies on TVS and MRI for CSP were collected from PubMed, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang data, and Chinese Scientific Journal Database (VIP database) until April 1, 2024. Stata 15.0 software was used for data analysis. Mann-Whitney U-test was applied to compare the diagnostic efficiency of the TVS and MRI groups.

Results: Nine articles with 713 subjects were involved in this review. The pooled sensitivity (0.96, 95%CI: 0.94-0.97), specificity (0.90, 95%CI: 0.84-0.94), and DOR (197.28, 95%CI: 99.71-390.31) in the MRI group were higher than those (Sensitivity = 0.83, 95%CI: 0.77-0.87; Specificity= 0.74, 95%CI: 0.63-0.83; DOR = 13.66, 95%CI: 7.84-23.79) in the TVS group. The positive likelihood ratio and negative likelihood ratio of the MRI group were 9.56 (95%CI: 8.82-15.72) and 0.05 (95%CI: 0.03-0.07), while those of the TVS group were 3.21 (95%CI:2.18-4.74) and 0.24 (95%CI: 0.18-0.31), respectively. In the MRI and TVS groups, the area under the curve (AUC) of the summary receiver operating characteristic was 0.9497 and 0.86, respectively. The results of Mann-Whitney U-tests of the two groups showed significant differences in the pooled sensitivity (Z= -3.311, p < 0.001), specificity (Z= -2.123, p = 0.034), and DOR (Z= -3.272, p = 0.001).

Conclusion: Both MRI and TVS can effectively diagnose CSP. However, compared with TVS, MRI has better diagnostic accuracy for CSP, with higher sensitivity and specificity. Considering the good diagnostic accuracy of ultrasound, patients with ultrasound suspicion of CSP should be sent to a reference center where MRI can express its full diagnostic potential regarding depth, topography of invasion and myometral residue, which is useful for subsequent management.