MR imaging of peripheral nerve tumors of the lower extremity / 中华放射学杂志

ABSTRACT

Objective To evaluate MR imaging of peripheral nerve tumors of the lower extremity. Methods MR imaging of peripheral nerve tumors of the lower extremity in five cases proved by surgery and pathology were retrospectively reviewed. In all patients, routine scanning was performed in axial, coronal, and sagittal planes, including T 1-weighted and T 2-weighted images. In two patients (schwannomas), T 1WI were obtained following intravenous injection of Gd-DTPA. Results There were four schwannomas (three benign and one malignant) and one malignant neurofibroma. Tumors arose at the following sites leg ( n =2), popliteal region ( n =1), thigh ( n =1), and femoral region ( n =1). On T 1WI, tumors generally showed isointensity (two benign schwannomas) or lower-medium signal intensity to adjacent muscle with minimal inhomogeneity (one benign schwannoma, one malignant schwannoma, and one malignant neurofibroma). On T 2WI, tumors demonstrated inhomogeneous high signal intensity in all five patients. The target sign with peripheral hyperintense rim and central low intensity was see in two benign schwannomas on T 2WI. Conclusion MRI is useful in defining the location and extent of a lesion and in assisting the surgical planning. The target pattern appears to be a useful sign in the diagnosis of peripheral nerve tumors.