Differentiation of benign and malignant parotid tumors using deconvolution-based perfusion CT imaging: Feasibility of the method and initial results

Aim: We evaluated the feasibility of perfusion CT (CTP) of the parotid gland and attempted to differentiate benign from malignant tumors. Materials and methods: CTP was performed in 17 patients with benign tumors and 10 patients with malignant parotid tumors. Data were postprocessed by using deconvolution-based perfusion analysis. Postprocessing-generated maps showed blood flow (BF), blood volume (BV), mean transit time (MTT), and capillary permeability surface product (PS). Regions of interest were placed through the tumor site and the contralateral healthy parotid tissue. Ratios of the perfusion values between the tumors and the contrallateral healthy structures were also calculated. Pearson correlation coefficients were determined to compare the agreement between the two readers. Results: Perfusion maps of all tumors were successfully obtained. High Pearson correlation coefficients comparing the two readers' visually measured abnormalities were observed (r = 0.79-0.86, P = 0.001) for all perfusion maps, The MTT and PS values between malignant and benign tumors were not significantly different. The BF and BV values were statistically significant different between the benign and malignant tumors (0.00 < P < 0.02). Only the BV ratio criterion between malignant and benign neoplasms was statistically significant (P < 0.004). Conclusions: CTP of the parotid gland is feasible and may differentiate malignant from non-malignant lesions by means of absolute BF, BV and BV ratio values. (C) 2007 Elsevier Ireland Ltd. All rights reserved.