Transvaginal Color Mapping Ultrasound in the First Trimester Predicts Placenta Accreta Spectrum: A Retrospective Cohort Study

Abstract

Objectives-Ultrasound (US) prediction of placenta accreta spectrum (PAS) in the first trimester may be aided by postprocessing mechanisms employing color pixel quantification near the bladder-uterine serosal interface. Our objective was to create a postprocessing algorithm of color images to identify findings associated with PAS and compare quantification to sonologist impression in prospectively obtained cine US images.Methods-Transverse transvaginal (TV) US color cines obtained in the first trimester as part of a prospective study were reviewed. Investigators blinded to clinical outcomes reviewed anonymized cines that were archived and labeled the bladder-uterine serosal interface. Color pixels within 2 cm of the defined bladder-uterine serosal interface were ascertained using a Python-based plugin in the Horos open-source DICOM viewer. A sonologist classified the findings as suspicious for invasion, indeterminate, or normal. Statistical analysis was performed using Wilcoxon rank-sum test, Cochran-Armitage trend test, and calculation of receiver-operating characteristic (ROC) curves.Results-Fifty-four studies met inclusion criteria. Of those, six (11%) required hysterectomy with pathologic confirmation of PAS. Women requiring hysterectomy had a significantly higher color Doppler pixel area than those not requiring hysterectomy (P = .0205). A significant trend was identified in the sonologist impression of invasion (P = .0003). ROC's comparing sonologist impression to Doppler color imaging areas were comparable (P = .054).Conclusions-Color Doppler mapping in the first trimester showed an increase in color pixel area near the bladder-uterine serosal interface in women requiring cesarean hysterectomy with histologically confirmed PAS at time of delivery, compared to women without hysterectomy or pathologic evidence of PAS.

The Cesarean Scar of Pregnancy: Ultrasound Findings and Expectant Management Outcomes

“…The SMFM criteria was retrospectively applied and did not include color Doppler mapping criteria. We along with others have found a positive association between color Doppler mapping, but again establishing a discriminatory quantification remains problematic (20). Additionally, the definition of CSP was evolving during our study period, so our inclusion criteria was that of evidence of implantation of the basalis near the pressured location cesarean scar and within 5cm of the external os.…”

“…We along with others have found a positive association between color Doppler mapping, but again establishing a discriminatory quantification remains problematic. 20 Additionally, the definition of CSP was evolving during our study period, so our inclusion criteria were that of evidence of implantation of the basalis near the pressured location cesarean scar and within 5 cm of the external os. 9 10 11 14 15 16 Applying the SMFM US criteria yielded 43 women with positive findings but did not identify all high morbidity cases, nor did the positive findings offer an acceptable discriminatory assessment.…”

Placenta acrreta spectrum—first trimester, 2D and 3D ultrasound, and magnetic resonance imaging findings

“…In a prospective study, the first trimester ultrasound parameters associated with PAS were smaller distance from the inferior trophoblastic border to the external os, disruption of the bladder‐serosal interface, bridging vessels, anechoic areas, and least myometrial thickness 23 . First trimester color Doppler has shown an increase in color pixel area near the bladder–uterine serosal interface in women requiring cesarean hysterectomy with histologically confirmed PAS at the time of delivery 24 …”

“…23 First trimester color Doppler has shown an increase in color pixel area near the bladder-uterine serosal interface in women requiring cesarean hysterectomy with histologically confirmed PAS at the time of delivery. 24 MRI has been used as an adjunctive imaging modality for the assessment of PAS in the first trimester of pregnancy, with few case reports published in the literature, 25,26 but without adding diagnostic value to transvaginal ultrasound.…”