Assessment of pelvic organ prolapse with the Pelvic Inclination Correction System: defining the normal range and threshold to pathology

To define the normal range and threshold values for pathologic prolapse on MRI using the PICS line and assess its correlation with the pubococcygeal line (PCL). This prospective, IRB-approved study included 20 nulliparous volunteers and 18 prolapse patients (POP-Q Stage ≥ 2). Organ positions (bladder, cervix, anorectal junction) relative to PICS and PCL were measured on dynamic MRI. Differences in organ position were compared. Receiver-operating characteristic (ROC) analysis was performed to identify cutoff values for prolapse using the PICS line. The correlation between PICS and PCL measurements was tested with Spearman’s rank correlation. In volunteers, median bladder and cervix positions measured to the PICS at rest were − 2.7 cm and − 5.3 cm compared to − 1.9 cm and − 2.7 cm in patients (p < 0.001). During straining, bladder and cervix were at − 0.9 cm and − 3.2 cm in volunteers versus + 2.5 cm and + 2.5 cm in patients (p < 0.001). Correlation was strong for PICS and PCL measurements for all three compartments (δ = 0.883–0.970, p ≤ 0.001). AUCs of PICS for the anterior and middle compartment were 0.98 (95