Magnetic resonance imaging of placenta accreta

Abstract

Placenta accreta (PA) is a severe pregnancy complication which occurs when the chorionic villi (CV) invade the myometrium abnormally. Optimal management requires accurate prenatal diagnosis. Ultrasonography (USG) and magnetic resonance imaging (MRI) are the modalities for prenatal diagnosis of PA, although USG remains the primary investigation of choice. MRI is a complementary technique and reserved for further characterization when USG is inconclusive or incomplete. Breath-hold T2-weighted half-Fourier rapid acquisition with relaxation enhancement (RARE) and balanced steady-state free precession imaging in the three orthogonal planes is the key MRI technique. Markedly heterogeneous placenta, thick intraplacental dark bands on half-Fourier acquisition single-shot turbo spin-echo (HASTE), and disorganized abnormal intraplacental vascularity are the cardinal MRI features of PA. MRI is less reliable in differentiating between different degrees of placental invasion, especially between accreta vera and increta.

Association of placenta previa with a history of previous Cesarian deliveries and indications for a possible role of a genetic component

“…Although, there is not any statistically difference between ultrasound and magnetic resonance imaging (MRI) for diagnosing placenta percreta, high risk cases should be carefully evaluated by MRI in order to determine the degree of the invasion to adjacent organs. It was suggested in the literature to use MRI imaging when the placenta is located in the posterior wall of the uterus [ 13 , 14 ]. In the evaluation of the related complications in our series, we reported that seven cases were transferred to the ICU, 14 cases needed blood transfusions and eight underwent hysterectomy due to placenta invasion into the bladder, which was confirmed by MRI.…”

Evaluation of interobserver variability and diagnostic performance of developed MRI‐based radiological scoring system for invasive placenta previa

“…The cumulative radiological score (CRS) was defined as the sum of 5‐point Likert scale scores (1: definitely negative, 2: probably negative, 3: neutral, 4: probably positive, 5: definitely positive) for six MR features that were previously identified as features of invasive placenta …”

Interruption of Pregnancy in Women with the Uterine Scar: Potential Risks

“…To diagnose placenta increta in the second and third trimesters of pregnancy, magnetic resonance imaging (MRI) is used in recent years in case of dubious results of ultrasonography [22]. However, diagnostics with the help of ultrasonography (including colour Doppler) and MRI has not shown a statistically significant difference [35]. No valid criteria of MRI diagnostics are so far developed.…”