Janine Hoffmann1, Marc Exner2, Kristina Bremicker2, Matthias Grothoff3, Patrick Stumpp2, Susanne Schrey-Petersen4, Holger Stepan4. 1. Department of Obstetrics, University of Leipzig, Liebigstrasse 20a, 04103, Leipzig, Germany. janine.hoffmann@medizin.uni-leipzig.de. 2. Department of Radiology, University of Leipzig, Liebigstrasse 20, 04103, Leipzig, Germany. 3. Department of Radiology, University of Leipzig-Heart Center, Struempellstrasse 39, 04289, Leipzig, Germany. 4. Department of Obstetrics, University of Leipzig, Liebigstrasse 20a, 04103, Leipzig, Germany.
Abstract
PURPOSE: Uterine rupture during labor is a rare but life-threatening complication after previous cesarean section (CS). Prenatal risk is assessed using ultrasound thickness measurement of the lower uterine segment (LUS). Due to inhomogeneous study results, however, clinical obstetrics still lacks for standard protocols and reliable reference values. As 3 T magnetic resonance imaging (MRI) has not yet been sufficiently studied regarding LUS diagnostics after previous CS, we sought to evaluate its feasibility focusing on thickness measurements and typical characteristics of the CS-scar region in comparison to ultrasound and the intraoperative status. METHODS: In this prospective study, 25 asymptomatic patients with one previous CS and inconspicuous ultrasound findings were included. An additional 3 T MRI with either a T2-weighted Turbo-Spin-Echo or a Half Fourier-Acquired-Single-shot-Turbo-spin-Echo sequence in a sagittal orientation was performed. We analyzed categorical image quality, inter- and intra-rater reliability as well as anatomy, morphology and thickness of the LUS. Results were compared to ultrasound and intraoperative findings. RESULTS: MRI provided good to excellent image quality in all patients. The imaged structures presented with a high variability in anatomy and morphology. Image characteristics indicating the uterine scar were only found in 11/25 (44%) patients. LUS thickness measurements with MRI showed good inter- and intra-rater reliability but poor agreement with ultrasound. CONCLUSIONS: MRI is appropriate for additional LUS diagnostics in patients with previous CS. The strong individual variability of LUS-anatomy and morphology might explain the difficulties in establishing uniform diagnostic standards after CS.
PURPOSE: Uterine rupture during labor is a rare but life-threatening complication after previous cesarean section (CS). Prenatal risk is assessed using ultrasound thickness measurement of the lower uterine segment (LUS). Due to inhomogeneous study results, however, clinical obstetrics still lacks for standard protocols and reliable reference values. As 3 T magnetic resonance imaging (MRI) has not yet been sufficiently studied regarding LUS diagnostics after previous CS, we sought to evaluate its feasibility focusing on thickness measurements and typical characteristics of the CS-scar region in comparison to ultrasound and the intraoperative status. METHODS: In this prospective study, 25 asymptomatic patients with one previous CS and inconspicuous ultrasound findings were included. An additional 3 T MRI with either a T2-weighted Turbo-Spin-Echo or a Half Fourier-Acquired-Single-shot-Turbo-spin-Echo sequence in a sagittal orientation was performed. We analyzed categorical image quality, inter- and intra-rater reliability as well as anatomy, morphology and thickness of the LUS. Results were compared to ultrasound and intraoperative findings. RESULTS: MRI provided good to excellent image quality in all patients. The imaged structures presented with a high variability in anatomy and morphology. Image characteristics indicating the uterine scar were only found in 11/25 (44%) patients. LUS thickness measurements with MRI showed good inter- and intra-rater reliability but poor agreement with ultrasound. CONCLUSIONS: MRI is appropriate for additional LUS diagnostics in patients with previous CS. The strong individual variability of LUS-anatomy and morphology might explain the difficulties in establishing uniform diagnostic standards after CS.