Joachim Bas1, Augustin C Ogier1, Arnaud Le Troter1, Emilien Delmont1, Benjamin Leporq1, Lauriane Pini1, Maxime Guye1, Amandine Parlanti1, Marie-Noëlle Lefebvre1, David Bendahan1, Shahram Attarian2. 1. From the Reference Center for Neuromuscular Diseases and ALS (J.B., E.D., A.P., S.A.) and CIC-CPCET (M.-N.L.), La Timone University Hospital, Aix-Marseille University; Aix-Marseille University (A.C.O., A.L.T., L.P., M.G., D.B.), CNRS, Center for Magnetic Resonance in Biology and Medicine; Aix-Marseille University (E.D.), UMR 7286, Medicine Faculty; Aix-Marseille University (S.A.), Inserm, GMGF; Aix Marseille University (A.C.O.), Université de Toulon, CNRS, LIS, Marseille; Université de Lyon (B.L.); and CREATIS CNRS UMR 5220 (B.L.), Inserm U1206, INSA-Lyon, UCBL Lyon 1, France. 2. From the Reference Center for Neuromuscular Diseases and ALS (J.B., E.D., A.P., S.A.) and CIC-CPCET (M.-N.L.), La Timone University Hospital, Aix-Marseille University; Aix-Marseille University (A.C.O., A.L.T., L.P., M.G., D.B.), CNRS, Center for Magnetic Resonance in Biology and Medicine; Aix-Marseille University (E.D.), UMR 7286, Medicine Faculty; Aix-Marseille University (S.A.), Inserm, GMGF; Aix Marseille University (A.C.O.), Université de Toulon, CNRS, LIS, Marseille; Université de Lyon (B.L.); and CREATIS CNRS UMR 5220 (B.L.), Inserm U1206, INSA-Lyon, UCBL Lyon 1, France. sattarian@ap-hm.fr.
Abstract
OBJECTIVE: To quantitatively describe the MRI fat infiltration pattern of muscle degeneration in Charcot-Marie-Tooth (CMT) type 1A (CMT1A) disease and to look for correlations with clinical variables. METHODS: MRI fat fraction was assessed in lower-limb musculature of patients with CMT1A and healthy controls. More particularly, 14 muscle compartments were selected at leg and thigh levels and for proximal, distal, and medial slices. Muscle fat infiltration profile was determined quantitatively in each muscle compartment and along the entire volume of acquisition to determine a length-dependent gradient of fat infiltration. Clinical impairment was evaluated with muscle strength measurements and CMT Examination Scores (CMTESs). RESULTS: A total of 16 patients with CMT1A were enrolled and compared to 11 healthy controls. Patients with CMT1A showed a larger muscle fat fraction at leg and thigh levels with a proximal-to-distal gradient. At the leg level, the largest fat infiltration was quantified in the anterior and lateral compartments. CMTES was correlated with fat fraction, especially in the anterior compartment of leg muscles. Strength of plantar flexion was also correlated with fat fraction of the posterior compartments of leg muscles. CONCLUSION: On the basis of quantitative MRI measurements combined with a dedicated segmentation method, muscle fat infiltration quantified in patients with CMT1A disclosed a length-dependent peroneal-type pattern of fat infiltration and was correlated to main clinical variables. Quantification of fat fraction at different levels of the leg anterior compartment might be of interest in future clinical trials.
OBJECTIVE: To quantitatively describe the MRI fat infiltration pattern of muscle degeneration in Charcot-Marie-Tooth (CMT) type 1A (CMT1A) disease and to look for correlations with clinical variables. METHODS: MRI fat fraction was assessed in lower-limb musculature of patients with CMT1A and healthy controls. More particularly, 14 muscle compartments were selected at leg and thigh levels and for proximal, distal, and medial slices. Muscle fat infiltration profile was determined quantitatively in each muscle compartment and along the entire volume of acquisition to determine a length-dependent gradient of fat infiltration. Clinical impairment was evaluated with muscle strength measurements and CMT Examination Scores (CMTESs). RESULTS: A total of 16 patients with CMT1A were enrolled and compared to 11 healthy controls. Patients with CMT1A showed a larger muscle fat fraction at leg and thigh levels with a proximal-to-distal gradient. At the leg level, the largest fat infiltration was quantified in the anterior and lateral compartments. CMTES was correlated with fat fraction, especially in the anterior compartment of leg muscles. Strength of plantar flexion was also correlated with fat fraction of the posterior compartments of leg muscles. CONCLUSION: On the basis of quantitative MRI measurements combined with a dedicated segmentation method, muscle fat infiltration quantified in patients with CMT1A disclosed a length-dependent peroneal-type pattern of fat infiltration and was correlated to main clinical variables. Quantification of fat fraction at different levels of the leg anterior compartment might be of interest in future clinical trials.