Volumetric analysis of Non-contrast Magnetic Resonance Lymphangiography in patients affected by lower extremities primary lymphedema

Aim Since the response to conservative and surgical treatments in lymphedema is based only on clinical evaluation, we want to propose a new technique for the volume calculation of lower extremities affected by lymphedema. Materials and methods Ten female patients affected by primary LE of the lower limbs (mean age 33 +/- 5 years; age range 16-42) underwent NCMRL in September 2019. Acquisition protocol included a STIR sequence (FOV 460 x 504 mm; matrix 315 x 384 pixel; voxel size 1.1 x 1.1 x 1.0 mm; TR 3000 ms; TE 254 ms; TI 160 ms). Two readers independently performed a manual segmentation with ITK-SNAP open-source software to assess the volume of the lower limbs. The agreement for volumetric segmentation between the two operators was assessed through intraclass correlation coefficient (ICC). Results Mean segmentation time was 5 +/- 0.3 min. ICC demonstrated excellent intra-examiner agreements for both readers 1 (ICC = 0.9991, p < 0.0001) and 2 (ICC = 0.9989, p < 0.0001). Inter-reader agreement was excellent (ICC = 0.9991, p < 0.0001). Conclusions Manual segmentation with ITK-SNAP of NCMRL examinations in patients affected by primary lower limb LE represents a reproducible procedure for an objective evaluation of volumes, useful for follow-up.