Pathologic characterization of human prostate tissue with proton MR spectroscopy

To assess the accuracy of magnetic resonance (MR) spectroscopy in documenting the chemical features of human prostate tissue and to ascertain if there are chemical criteria of diagnostic importance.

Seventy-seven prostate tissue specimens (peripheral zone, n = 61; transitional zone, n = 16) from 43 patients were analyzed with MR spectroscopy. Histologic features were compared with MR spectroscopic data. Statistical analysis was undertaken with analysis of variance and computer software.

Histologically identified carcinomas were determined by using MR spectroscopy with a sensitivity of 100% and a specificity of 94%. Histologically benign tissue from patients without carcinoma of the prostate was distinguished from malignant tissue with a sensitivity of 100% and a specificity of 94%. When benign specimens from patients with cancer elsewhere in the prostate were included in the database, MR spectroscopy helped distinguish benign prostatic hyperplasia from adenocarcinoma with a sensitivity of 97% and specificity of 88%. Depleted citrate and elevated choline levels alone were not accurate markers of malignancy, since citrate levels remain high when a small amount of malignant disease is present. Carcinomas missed at routine histologic examination were identified with MR spectroscopy and confirmed with specialized, nonstandard histologic examination.

By comparing the intensity of resonances assigned to choline, creatine, lipid, and lysine, MR spectroscopy can depict prostate carcinoma with a high degree of sensitivity and specificity. Citrate and choline resonances alone are not sufficiently accurate markers for distinguishing between various patterns of prostatic disease.