Purpose.

Assessment of the capabilities of MRI in the diagnosis of placenta invasion, study of the value of diagnostic signs of placental invasion. Development of a unified scoring system for the received data "MAPI-RADS (Morbidly Adherent Placenta Imaging Reporting and Data System)".

Material and Methods. The retrospective study is based on an analysis of the results of MRI in 212 pregnant women with placenta accreta performed at 26-34 weeks of gestation. Evaluation of images and signs of invasive placenta, correlation analysis with intraoperative data were carried out. To validate the significance of diagnostic features as predictors of placenta accretion, a statistical analysis of the data obtained was performed to determine the frequency of occurrence of each feature, and a mathematical calculation of the value of each criterion obtained, expressed in points.

Results. Diagnostic criteria have been developed, divided into 2 groups. The main criteria (diagnostic value 2 points): bulging of the uterine wall with prolapse of the lower uterine segment; thinning of the myometrium in the area of attachment of the placenta; the presence in the structure of the placenta of vascular "lacunae"; the presence of vascular "ribbons"; retroplacental hypointense "shadow". Additional criteria (1 point for the first and second, 3 points for the third criteria): vascular plethora and varicose veins of the uterine wall; central/marginal placenta presentation; the spread of the placenta outside the uterine wall (with pl.percreta). For the final diagnosis, the MAPI-RADS system was developed, which consists in summing the scores obtained during the interpretation, with the class of pathological attachment of the placenta being set.

Conclusions. The developed system "MAPI-RADS" allows identifying, systematizing and quantifying the signs of placenta invasion obtained during the study, and makes it possible to set a class corresponding to the degree of placental ingrowth, correlating with intraoperative data.