Quantitative and longitudinal assessment of human placental inflammation using diffusion basis spectrum imaging

Besides exchanging nutrients, gases, and wastes, placenta is an intermediary between maternal and fetal immune systems. However, no method exists to safely image and monitor placental inflammation during pregnancy. We customized a Magnetic Resonance Imaging (MRI) method, diffusion basis spectrum imaging (DBSI), to measure immune cells in placenta. We validated placental DBSI in simulations and ex-vivo specimens, then applied it to 202 MRI scans from 82 patients whose placentas were classified as non-inflammation (n = 70) or inflammation (n = 12). Our method imaged the 3D distribution of immune cells, revealing significantly greater infiltration in the inflammation placentas from early (2.8% ± 0.7% vs. 4.8% ± 0.65%, p < 0.01) to late pregnancy (4.75% ± 0.9% vs. 7.25% ± 2.13%, p < 0.01). DBSI detects elevated immune cell infiltration associated with placental inflammation and enables non-invasive imaging of placental inflammation, offering early detection and monitoring throughout pregnancy, facilitating personalized care and potentially improving pregnancy outcomes without ionizing radiation.