[A study on MRI diagnosis for primary squamous cell carcinoma in oral and maxillofacial regions]

The purpose of this study is to clarify the characteristics of MR imaging of primary squamous cell carcinoma in oral and maxillofacial regions and whether neoplastic infiltration can be delineated accurately. Seventy patients with squamous cell carcinoma underwent precontrast T1 and fast T2-weighted imaging and postcontrast T1-weighted imaging and dynamic study using the MRI system (1.5T). They were classified into 3 groups, untreated, preoperatively treated, and local recurrent group. No differences in the intensity of whole tumors, the relative intensity in the region of intensity (ROI), internal uniformity, and the time intensity curves were found among three groups. Tumor margins and staining appearances during the dynamic study showed remarkable differences. The observers of MR imaging divided the tumor size into T classifications, which agreed with clinical classification in most cases. The rate of concordance with histopathological classification were considerably high in the untreated cases (86%). In conclusion, MR imaging is a reliable technique for delineating the characteristics and infiltration of primary carcinomas with higher sensitivity when postcontrast T1-weighted imaging is applied to cases of unclear margin on precontrast T1- and T2-weighted imaging and dynamic study on the recurrent cases.