RESUMO
BACKGROUND: The incidence of placenta accreta spectrum (PAS) disorders has increased rapidly in recent years and is associated with several maternal and neonatal complications. Intravoxel incoherent motion (IVIM) imaging is a method which can assess placental perfusion quantitatively. Therefore, the first aim of this study was to investigate whether patients with adverse maternal and neonatal outcomes of PAS disorders differed in the parameters from IVIM. A second aim was to identify these parameters for adverse peripartum outcome in gravid patients at risk for PAS. METHODS: The subject group consisted of patients with placenta previa, in which 75 patients had PAS disorders and 24 patients did not have PAS disorders between 28+0 and 39+6 weeks, respectively. All women underwent magnetic resonance imaging (MRI) examination including an IVIM sequence with 8 b values on a 1.5T scanner. The perfusion fraction (f), pseudodiffusion coefficient (D*), and standard diffusion coefficient (D) were calculated. All medical records were received postpartum. The final degree of placental invasion was established either by placental villi alterations from a placental sample or from maternity records of the women's general practitioners. RESULTS: Women with PAS disorders had a higher perfusion fraction (34.12%) than women without the disease (29.39%) (P<0.05). The perfusion fraction was 36.86% in women with massive blood loss and was 35.15% in women requiring transfusion, which was higher than women without massive blood loss and not requiring transfusion (P<0.05). The D value was 1.65×10-3 mm2/s in women with low birth weight, which was lower than that in women with appropriate birth weight (1.70×10-3 mm2/s) (P<0.05). CONCLUSIONS: Patients with PAS disorders differed in placental perfusion fraction from women without PAS disorders. The f and D value may be used to recognize patients with certain adverse clinical outcomes.
RESUMO
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 1.5 T scanner. Perfusion fraction (f), pseudodiffusion coefficient (D*) and 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.