Reproducibility of magnetic resonance spectroscopy in patients undergoing dialysis and evaluation of the therapeutic response of tumors.

ABSTRACT

RATIONALE AND OBJECTIVES: The reproducibility of repeated magnetic resonance (MR) spectroscopy was studied in patients undergoing dialysis and treatment of a variety of malignant tumors. METHODS: Localized MR spectra were obtained using a 1.5-T system by image-selected in vivo spectroscopy. Total metabolite signal was integrated between phosphomonoester and beta-adenosine triphosphate resonance. We termed this measurement AREA. RESULTS: Intrapatient variability was evaluated on repeated thigh muscle spectroscopy for 10 patients. Sequential spectra of 10 malignant tumors of the extremities were analyzed and compared with the histology of surgical specimens in seven patients. Intrapatient variability in AREA was calculated as 14.0%. The extent of necrosis and AREA ratio (definition AREA post-therapy/AREA pretherapy) were as follows; 6.1% in > 90% necrosis, 43% in 50% to 90% necrosis, and 79% in < 50% necrosis. CONCLUSIONS: Localized MR spectra are fairly reproducible and may relate to treatment efficacy.