MRI MAPPING OF POSTRECONSTRUCTIVE EDEMA FOLLOWING FEMOROPOPLITEAL BYPASS-SURGERY

We have used T1 MR images to map the distribution of water contributing to the edema which follows femoropopliteal bypass surgery. Spin-echo images and true parametric T1 images were made at the same time. The spin-echo images were used to identify the tissue anatomy. The extra fluid contributing to the edema distributes in two phases: a volume equivalent to 5% of the leg volume is distributed throughout the leg tissue, while the excess fluid collects in a localized annulus lying adjacent to the fascia. The T1 in the annulus can be as high as 4 sec, indicating build up of free fluid in this region. Although most of this free fluid lies in the subcutaneous fat, there is a component which lies underneath the fascia in the muscle compartment.