Value of magnetic resonance imaging in assessing bone destruction in head and neck lesions

We utilized low-field magnetic resonance imaging (MRI) to evaluate 12 patients with head and neck lesions and suspected skull base or facial bone destruction. All except one had high resolution computed tomography (CT). MRI was performed on a 0.15 tesla (low-field) resistive unit, with routinely good resolution due mainly to the use of specially designed rf receiver coils (surface coils). T1 and T2 weighted spin echo images were performed in all cases. In three instances axial, coronal, and sagittal images were done. All CTs were done with high resolution techniques on state-of-the-art equipment. Comparison of the CT and MR images (at low-field strength) showed that MRI's main strength lies in its freedom to perform images in any plane and to visualize intracranial lesions with early brain involvement. Otherwise, the two modalities are comparable. Bone destruction seen on CT was always detectable on MRI, although CT is clearly superior in resolving bone detail. MRI is recommended when direct coronal CT scans are not obtainable to evaluate superiad tumor extension. The improved visualization of nasopharyngeal soft tissue and cavernous sinus region is likely to make MRI the examination of first choice in evaluating lesions of the nasopharynx, skull base, and cavernous sinus.