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.
Keywords
Abnormal placental vascularity - dark intraplacental bands - magnetic resonance imaging
- placenta accreta
