Dynamic MR of the pelvic floor: Influence of alternative methods to draw the pubococcygeal line (PCL) on the grading of pelvic floor descent

Simona Picchia; Marco Rengo; Davide Bellini; Damiano Caruso; Eliseo Pironti; Roberto Floris; Andrea Laghi

doi:10.1016/j.ejro.2019.05.002

Dynamic MR of the pelvic floor: Influence of alternative methods to draw the pubococcygeal line (PCL) on the grading of pelvic floor descent

Eur J Radiol Open. 2019 May 20:6:187-191. doi: 10.1016/j.ejro.2019.05.002. eCollection 2019.

Authors

Simona Picchia¹, Marco Rengo¹, Davide Bellini¹, Damiano Caruso², Eliseo Pironti³, Roberto Floris⁴, Andrea Laghi²

Affiliations

¹ Department of Radiological Sciences, Oncology and Pathology, "Sapienza" - University of Rome, Diagnostic Imaging Unit - I.C.O.T. Hospital, I.C.O.T, Via F. Faggiana 34, 04100 Latina, Italy.
² Department of Radiological Sciences, Oncology and Pathology, "Sapienza" - University of Rome, Radiology Unit - Sant'Andrea University Hospital, Via di Grottarossa, 1035, 00189 Rome, Italy.
³ Casa di Cura Privata Villa Benedetta Hospital, Circonvallazione Cornelia, 65, 00165, Rome, Italy.
⁴ "Tor Vergata"- University of Rome. Department of Radiology - Tor Vergata Hospital, Viale Oxford, 81, 00133 Roma RM, Italy.

Abstract

Objective: To evaluate the impact of the pubococcygeal line (PCL) position on hiatal descent grading, comparing the method recommended by the official guidelines with the other two most common methods reported in literature.

Methods: Female patients prospectively included performed dynamic-MR (1,5 T) in supine position. Rectum and vagina were filled with ultrasound gel. MR protocol included TSE T2 weighted sequences on axial/sagittal/coronal planes and steady-state sequences (FIESTA) on midsagittal plane during three phases (rest, strain and defecation). On each phase, the posterior point of PCL was traced in the region recommended by the official guidelines (last coccygeal joint or PCLcc) and in the other two regions: coccyx's tip (PCLtip) and sacrococcygeal joint (PCLsc). The resulting grades of pelvic floor descent (according to HMO-System) were compared. Inter-reader and intra-reader agreement were evaluated.

Results: The final population consisted of 60 patients (56yy±10). No significant differences in grading were observed using PCLtip and PCLcc in all phases (p = 0.3016/0.0719/0.0719 during rest/strain/defecation). Using PCLsc, the grading was significantly overestimated compared to PCLcc in all phases (p = 0.0041/0.0001/0.0001 during rest/strain/defecation). Inter-reader and intra-reader agreement were significantly higher using PCLtip (p < 0.05).

Conclusions: PCLtip is a reliable and highly reproducible option to the official PCLcc to correctly grade the pelvic floor descent and could be used when the PCLcc is not clearly visible. The use of PCLsc overestimates the grading compared to the official PCLcc and should not be used to avoid wrong patients' management.

Keywords: Defecography; FIESTA, Fast Imaging Employing Steady-state Acquisition; FOV, field of view; Fecal incontinence; Incontinence; MR, magnetic Resonance; Magnetic resonance; Mcc, M line obtained by PCLcc; Msc, M line obtained by PCLsc; Mtip, M line obtained by PCLtip; PCL, pubococcygeal line; PCLcc, pubococcygeal line posterior point on the last coccygeal joint; PCLsc, pubococcygeal line posterior point on the sacrococcygeal joint; PCLtip, pubococcygeal line posterior point on the tip of the coccyx; PFD, pelvic floor dysfunction; Pelvic floor; Pelvic pain; STARD, Standards for Reporting of Diagnostic Accuracy; TSE, turbo spin echo; Urinary.