Assessment of Subfascial Muscle/Water and Fat Accumulation in Lymphedema Patients Using Magnetic Resonance Imaging.

Background: In patients with arm or leg lymphedema, more fat has been found in the epifascial compartment of the edematous limb compared to the healthy limb. However, not much is known about subfascial fat accumulation in these patients. This study aims to investigate the intramuscular and intermuscular fat and muscle/water volume in lymphedema patients. The excess of intramuscular and intermuscular fat volume was also compared to the excess epifascial fat volume, the excess limb volume, and the duration of lymphedema. Methods and Results: Data from 13 patients (seven arm and six leg lymphedemas) were acquired using a 1.5 T magnetic resonance imaging (MRI) scanner before liposuction and at five time points (4 days, 4 weeks, 3 months, 6 months, and 1 year) after liposuction. From water-fat imaging, fat and muscle/water volumes within the intramuscular and intermuscular compartments were calculated. The relative excess volume was defined as (volume of edematous limb-volume of healthy limb)/volume of healthy limb. Elevated relative excess volumes of intramuscular and intermuscular fat were found at all time points. A decrease in the relative excess volume of muscle/water over time was found. This decrease was not correlated to the relative excess of epifascial fat volume, the relative excess of limb volume, or the duration of lymphedema. Conclusions: An excess fat volume was found in the intramuscular and intermuscular compartments in lymphedema patients. The results suggest that the subfascial compartment needs to be studied separately as no correlation between intramuscular/intermuscular fat accumulation and other measured parameters was found.