Background & objective: Blood flow patterns with CT perfusion imaging (CTPI) had been innovated to delineate abnormal hemodynamic lesions in the liver, brain, and kidney. This study was to evaluate the blood flow patterns of pulmonary masses by CTPI, and determine the value of CTPI in differential diagnosis among benign, malignant, and inflammatory masses.
Methods: Fifty-two patients with previously diagnosed pulmonary masses (37 with malignant masses, 7 with benign masses, and 8 with inflammatory masses) underwent dynamic CTPI. Time-density curves (TDC) of artery, vein, and pulmonary masses as well as mass perfusion images and parameters including perfusion volume (PV), peak height (PH), mean transit time (MTT) and blood volume (BV) were obtained by Phlips CT-perfusion software.
Results: The values of PV, PH, and BV were significantly higher in malignant masses and active inflammatory masses than in benign masses [(27.63+/-15.06) ml.min(-1).ml(-1) and (30.80+/-20.33) ml.min(-1).ml(-1) vs. (11.81+/-3.74) ml.min(-1).ml(-1), (28.46+/-12.07) Hu and (32.15+/-15.89) Hu vs. (10.41+/-3.77) Hu, (21.64+/-10.97) ml/100 g and (28.38+/-14.55) ml/100 g vs. (10.61+/-5.33) ml/100 g, P<0.01]. However, the differences of MTT among malignant, inflammatory, and benign masses were not significant [(28.39+/-21.66) s, (25.91+/-14.57) s, and (29.86+/-13.57) s, P=0.928]. No significant differences in the 4 parameters were found between malignant and inflammatory masses. When PV >20 ml.min(-1).ml(-1) and pH >15 Hu were set as a diagnostic threshold (excluded active inflammatory masses), the sensitivity, specificity, and accuracy were 91.9%, 100%, and 84.1%, respectively.
Conclusion: CT perfusion imaging provides quantitative information about blood flow patterns of pulmonary masses and is an applicable diagnostic method for differentiating pulmonary masses.