MR imaging of primary, secondary, and mixed forms of lymphedema.

PURPOSE

To describe the pathological features and assess the diagnostic information of different MR sequences in patients with primary, secondary, and mixed (phlebo-, lipophlebo-, or lipolymphedema) forms of lymphedema of the lower leg.

MATERIAL AND METHODS

In 26 patients with clinical diagnoses of primary (n=10), pure secondary (n=4), mixed (n=9) and combined secondary and mixed forms of lymphedema (n=3), MR imaging was performed with coronal and axial T1 SE, T2 TSE, fat-suppressed (SPIR) T2 sequences and axial T1 SE after i.v. injection of Gd-DTPA.

RESULTS

In 24 patients there was a honeycomb pattern in the subcutis with a signal intensity corresponding to fluid (n=11), fibrosis (n=3), or both (n=10). Five patients with primary lymphedema showed subfascial fluid accumulation. Dermal edema was noted in 23 patients. Fat or edema components in the muscles were mostly seen in patients with phlebolymphedema. The honeycomb pattern was best seen on coronal T1 images, and fluid accumulations on axial SPIR-T2 images. Fibrosis was only assessible from the T2 TSE sequence. Gd-DTPA did not improve the diagnostic information.

CONCLUSION

For evaluation of lymphedema and its mixed forms, an axial T2-weighted SPIR sequence in conjunction with a coronal T1 SE sequence are sufficient.