[Role of MR imaging in the diagnosis and evaluation of sarcoidosis].

In the diagnosis of mediastinal and/or hilar lymphadenopathy in patients with sarcoidosis, MR (magnetic resonance) imaging is similar to CT in its ability to detect these lesions. Values of T1 and T2 of lymph nodes of sarcoidosis do not appear to differ from those of other diseases. The T1-weighted images are most helpful in distinguishing swollen lymph nodes from fat tissue and in defining vascular anatomy. Using the coronal or sagittal plane, MR imaging is more able to demonstrate subcarinal or aorticopulmonary nodes better than CT. However, it is inferior to CT in the evaluation of the pulmonary parenchymal involvement of sarcoidosis. On the other hand, in the diagnosis of CNS sarcoidosis and nodular type muscular sarcoidosis, MR imaging should be applied as the primary imaging modality. The use of Gd-DTPA increases the sensitivity of MR imaging in the detection of CNS sarcoidosis, especially, in patients with meningeal involvement. Both T1- and T2-weighted axial spin-echo images show specific findings in patients with the nodular type of muscle lesions.