Localised in vivo ¹H spectroscopy of human bone and soft tissue tumours

Abstract

Localised ¹H in vivo magnetic resonance spectroscopy was applied to fibrous and bone tumours before and during cytostatic treatment and radiotheraphy. The results of 24 studies in 18 patients with malignant tumours of the leg or pelvis are presented including cases of sarcoma, malignant fibrous histiocytoma, multiple myeloma, malignant lymphoma and metastasis. A double spin echo localisation method with water suppression was implemented on a 1.5 Tesla whole body unit. Voxel size was (13 mm)³ or (20 mm)³. The most common resonances besides lipids (16/18) were those of choline (10/18) and creatine (5/18). Creatine was always decreased in comparison to choline and often absent from tumour spectra. Additional resonances with phase distorsions from J-coupling (chemical shift region 1.8–2.5 and 2.2–4.0 ppm) were recorded. In the presence of lipids, lactate remained undetectable because special editing techniques were not available. Significant spectral differences between different tumour types were not evident. In about 30% of the investigations the spectra contained only water and lipid signals. Follow-up studies in three patients during radio- and chemotheraphy showed a decrease in metabolites (choline, creatine, unassigned signals between 1.0 and 2.5 ppm) after weeks and months. The decrease in choline was most pronounced paralleled by an increase in lipid/choline ratios.