This study sought to correlate quantitative presurgical
proton magnetic resonance spectroscopic imaging (1H-MRSI) and diffusion imaging (DI) results with quantitative histopathological features of resected
glioma tissue. The primary hypotheses were (1)
glioma choline signal correlates with cell density, (2)
glioma apparent diffusion coefficient (ADC) correlates inversely with cell density, (3)
glioma choline signal correlates with cell proliferative index. Eighteen adult
glioma patients were preoperatively imaged with 1H-MRSI and DI as part of clinically-indicated MRI evaluations. Cell density and proliferative index readings were made on surgical specimens obtained at surgery performed within 12 days of the radiologic scans. The resected tissue location was identified by comparing preoperative and postoperative MRI. The
tumor to contralateral normalized
choline signal ratio (nCho) and the ADC from resected
tumor regions were measured from the preoperative imaging data. Counts of nuclei per high power field in 5-10 fields provided a quantitative measure of cell density. MIB-1 immunohistochemistry provided an index of the proportion of proliferating cells. There was a statistically significant inverse linear correlation between
glioma ADC and cell density. There was also a statistically significant linear correlation between the
glioma nCho and the cell density. The nCho measure did not significantly correlate with proliferative index. The results indicate that both ADC and spectroscopic
choline measures are related to
glioma cell density. Therefore they may prove useful for differentiating dense cellular neoplastic lesions from those that contain large proportions of acellular necrotic space.