Assessment of Spectral Attenuated Inversion Recovery (SPAIR) MR Imaging: Normal and Osteomyelitis in the Mandible

Abstract

To describe signal characteristics of normal structures in the mandibular region using spectral attenuated inversion recovery (SPAIR) magnetic resonance (MR) imaging and evaluate the usefulness of SPAIR MR images in mandibular osteomyelitis compared with T1- and T2-weighted spin echo (SE) images. SPAIR MR images of 212 normal subjects and T1- and T2-weighted SE images of 21 subjects of mandibular osteomyelitis were evaluated. T1- and T2-weighted images were obtained in all patients. MR images were evaluated in terms of signal characteristics of normal and abnormal mandibular bone marrow, and surrounding soft tissue. In normal subjects, the mandibular bone marrow demonstrated low signal intensities (100%) and cortical bone showed no signal intensities (100%) on SPAIR images. In surrounding soft tissue of normal subjects, the submandibular glands demonstrated high signal intensities (100%), the parotid glands showed intermediate to high signal intensities (100%), the sublingual glands showed high (92%) and intermediate to high (8%) signal intensities, the lymph nodes showed high signal intensities (100%), and the masseter muscles showed intermediate signal intensities (100%) on SPAIR images. The lesions in mandibular bone marrow were low (86%) and low to intermediate (14%) signal intensities on T1-weighted images and high (52%), intermediate to high (33%), and intermediate (15%) signal intensities on T2-weighted images. On SPAIR images, the signal intensities resulted in high (86%), and intermediate to high (14%). The use of SPAIR imaging is useful for evaluating normal mandibular bone marrow and detecting osteomyelitis in the mandible and identifying the spread of inflammation to soft tissue.