Can introvoxel incoherent motion MRI be used to differentiate patients with placenta accreta spectrum disorders?

Abstract

Objective Background The incidence of PAS disorders increased rapidly in recent years, and introvoxel incoherent motion (IVIM) MRI has been applied in the assessment of placenta. The study aims to investigate whether the parameters from IVIM can be used to differentiate patients with PAS disorders complicating placenta previa and secondly to differentiate different categories of PAS disorders. Methods The study participants were comprised of 99 patients with placenta previa, including 16 patients with placenta accreta, 51 patients with increta, 8 patients with percreta and 24 patients without PAS disorders between 28+0 and 39+6 weeks. IVIM MRI was performed on a 1.5T scanner. Perfusion fraction (f), pseudodiffusion coefficient (D*) and standard diffusion coefficient (D) were calculated. Results Women with PAS disorders had a higher perfusion fraction (p=0.019) than women without the disease. Multiple comparisons showed perfusion fraction in patients without PAS disorders was significantly lower than in patients with placenta accreta and percreta(P=0.018 and 0.033 respectively), but was not lower than in patients with increta(p=1). Conclusion Patients with placenta accreta and percreta differed in placental perfusion fraction from women with increta and without PAS disorders.

Standard diffusion-weighted, diffusion kurtosis and intravoxel incoherent motion MR imaging of the whole placenta: a pilot study of volumetric analysis

“…The IVIM is a bi-exponential model that describes microscale translational movement within imaging voxels with f, representing the relative amount of blood flow in the vascular bed (34). The mean placental perfusion fraction was 41%, similar to the research of Siauve et al (42.5%) (38), but higher than in other previous reports (21)(22)(23)26,31,34). Controversy remains whether the perfusion fraction is stable during gestation or whether it increases or decreases (26,32,33,38).…”

“…Intravoxel incoherent motion MR imaging (IVIM) is a biexponential model initially proposed by Le Bihan (19) that helps distinguish pure molecular diffusion from capillary perfusion when separating the fast perfusion-driven component from a slow diffusion-driven component. First introduced into placental MRI in the 2000s (20)(21)(22), IVIM is now widely used in the evaluation of placenta accreta spectrum disorders (PAS) disorders, placental insufficiency, and small for gestational age (GA) neonates (23)(24)(25)(26).…”