Uterine scarring from caesarean section (CS) can lead to subsequent abnormally adherent or invasive placenta. Failure to recognise Placenta Accreta Spectrum disorders prior to delivery can potentially cause catastrophic bleeding and death. Complex surgical interventions may be required to remove placental invasion of the uterine myometrium and nearby organs. Antenatal detection and correct PAS grading are important to plan delivery. Current ultrasound and MRI imaging are limited to subjective assessment of vascular invasion. We propose a multi-compartment model1 that can quantify vascularity and proportion of abnormal placentation across the previous CS scar for objective diagnosis and to assist surgical planning.