A preliminary study of ¹H-MRS in diagnosis of benign and malignant pleural effusions

Objective: To investigate the feasibility of magnetic resonance spectroscopy (MRS) in the diagnosis of benign and malignant pleural effusions. Methods: Samples of 46 cases of pleural effusion were collected in clinics after performing pleurocentesis. Among the obtained samples, 20 cases were benign pleural effusion (14 cases of tuberculosis and 6 cases of pneumonia) and 26 cases were malignant pleural effusion (18 cases of primary bronchogenic carcinoma, 5 cases of breast carcinoma, 2 cases of primary hepatic carcinoma, and 1 case of gastric carcinoma). The effusion pleural samples were centrifuged and subjected to ¹H MRS examination using a 1.5T MR device. Results: The main metabolites in the pleural effusion contain lactate, choline, creatine, myo-inositol (MI), and fatty acids. Area of Lactate: pleural effusion from tuberculosis (5.19 ± 1.31), pneumonia (6.08 ± 1.56) and malignant pleural effusion (2.40 ± 0.43) has statistic significance (F = 8.45, P < 0.01). Area of choline: pleural effusion from tuberculosis (2.75 ± 0.91), pneumonia (3.27 ± 1.21) and malignant pleural effusion (6.76 ± 1.73) has statistic significance (F = 2.98, P < 0.01). Area of MI: pleural effusion from tuberculosis (2.71 ± 1.19), pneumonia (2.25 ± 0.81) and malignant pleural effusion (5.83 ± 2.08) has statistic significance (F = 38.49, P < 0.01). Area of lactate (t = -1.04, P > 0.05), choline (t = -0.58, P > 0.05) and MI (t = 1.19, P > 0.05) between pleural effusion from tuberculosis (5.19 ± 1.31) and pneumonia has no statistic significance. Conclusions: Benign and malignant pleural effusions show different MRS characteristics. ¹H MRS has certain clinical value in the differentiation of benign and malignant pleural effusions. (authors)