31-P MR SPECTROSCOPY OF A LEG LYMPHANGIOSARCOMA

In a 64 year old man with a large, low grade lymphangiosarcoma of the right thigh, we correlated the results of in vivo 31-P-magnetic resona nce spectroscopy (MRS), proton magnetic resonance imaging (MRI), and d igital subtraction (DSA) with the pathologic specimen and histology. T he 31-P MRS spectra of the tumor showed well-resolved peaks as follows : intense PCr (phosphocreatine), PDE (phosphodiester) and Pi (inorgani c phosphate), and low PME (phosphomonoester). The Pi peak revealed an intratumor pH of 6.96 compared with 7.16 of normal skeletal muscle. Th e lower PME signal was consistent with low histopathologic mitotic act ivity of the tumor.