['Squamous cell cancer (SCC) of the head and neck, like other malignancies, should be reported with regard to TNM classification and treated accordingly. Sole anatomic imaging has its drawbacks, as early lesion detection often remains challenging, non-neoplastic processes can mimic malignancies and there are doubts concerning the extent of tumour. The purpose of this study was to perform assessment of head and neck squamous cell cancer and surrounding tissue, in order to examine the relationship between perfusion measurements derived from CT perfusion imaging (CTP) and histologic evaluation of resected tissue.', 'We prospectively evaluated 21 primary SCC of the oral cavity and oropharynx, using contrast enhanced CT of the head and neck followed by CTP examination at the level of tumour. Blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability (PS) values were calculated with use of manually drawn regions of interest (ROIs) over the lesions and on the contralateral side. Results were compared with histologic analysis of resected tissue.', 'CTP was possible in all twenty one patients, but one did not undergo surgery. Of the remaining twenty, four had retromolar trigone cancer, nine had tongue cancer and seven had tonsil cancer. We found significant differences between infiltrated and healthy tissue. Differentiation was most reliable by using blood flow (BF), permeability surface (PS) and blood volume (BV).'] Is computed tomography perfusion examination helpful in evaluating the extent of oropharyngeal and oral cavity cancer?