Estimation of relative blood volume in head and neck squamous cell carcinomas.

Purpose: MR based first-pass method can be utilized to obtain hemodynamic information in the head and neck region. The purpose of this study was to estimate the regional relative blood volume (rBV) in head and neck tumors, which is useful for tumor staging and tumor biopsy.

Methods: Eighteen patients with head and neck tumors (17 squamous cell carcinomas, 1 hemangiopericytoma) were studied on a 1.5-T system. Conventional T1-weighted MR images and T2-weighted images and sequential T2*-weighted images were obtained. During repetitive image sequence acquisition, a bolus (0.2 mmol/kg) of gadopentetate dimeglumine was mechanically injected. Image processing of the dynamic raw data was performed on a pixel-by-pixel basis.

Results: Regional relative blood volume maps of the head and neck were successfully reconstructed in all (18/18) patients. The regional relative blood volume values within the tumor area of squamous cell carcinoma were 7.0 +/- 2.8, normalized on muscle, whereas the rBV of a single hemangiopericytoma was 11.6. The difference of rBV values of tumor and muscle was highly significant at statistical evaluation (p < 0.001).

Conclusions: Relative blood volume imaging of head and neck tumors is valid using MR-based first-pass method. This method provides hemodynamic information which is not available from conventional MR imaging and is promising for further characterization of head and neck tumors