ROLE OF COLOR DOPPLER U/S AND MRI FOR DIAGNOSIS OF PLACENTA ACCRETA

Abstract

Background: The worldwide incidence of placenta accreta (PA) is rapidly rising, following the trend of increasing cesarean delivery. Antenatal diagnosis is highly desirable because outcomes are optimized when delivery occurs at a level III or IV maternal care facility before the onset of labor and with avoidance of placental disruption. The primary diagnostic modality for antenatal diagnosis is obstetric color Doppler ultrasonography (CDUS). Magnetic Resonance Imaging (MRI), although widely employed, has yet to clearly demonstrate a significant improvement in management, but it is expensive and requires expertise that is rarely available in most low-income countries and many medium income countries. Objective: To evaluate and compare the accuracy of CDUS and MRI in the diagnosis of PA and to define the most relevant specific features that may predict placental invasion. Patients and methods: A case control study was conducted at AL- Azhar University Hospitals during the interval between November 2017 and November 2020, total set of 50 patients in the third trimester of pregnancy with diagnosis of placenta accreta and at least one previous caesarean section (CS). Patients were equally divided into 2 groups; Group I: Control group diagnosed as PA by CDUS. Group II: Study group diagnosed as placenta accreta by CDUS and subjected to MRI. With inclusion and exclusion criteria, all included women was subjected to; history taking, physical examination, obstetric CDUS and MRI scan was added for Group II only to pick up features suggestive of PA. Results: The sensitivity and specificity of CDUS were 100% and 72%, whereas the sensitivity and specificity of MRI were 76% and 52%, respectively, in their ability to diagnose PA. The highest sensitivity of individual CDUS and MRI markers in predicting PA were obliteration of the retroplacental clear space (63.6%) and focal interruption in the myometrial wall (73.7%), respectively. Conclusion: Ultrasound imaging is the mainstay of screening for placenta accreta. MRI appears to be complementary to ultrasonography, especially when there are few ultrasound signs or if there is a suspicion for invasion into surrounding organs.