[Clinical usefulness of thallium-201 single-photon emission CT in the patient with hypertrophic cranial pachymeningitis].

We report a 54-year-old female with rheumatoid factor-positive hypertrophic cranial pachymeningitis. At age of 51 years she developed headache, hearing loss, right vagal nerve palsy, and right accessory nerve palsy. MRI revealed thickening and gadolinium-enhancement of the cranial dura mater. The initial symptoms significantly improved with corticosteroid therapy. Two years later, she presented with severe headache and neck pain. Although gadolinium-enhanced MR images failed to show any change compared with those before recurrence, 201Tl single-photon emission CT (SPECT) showed a remarkable accumulation of thallium-201 in the dura mater. Furthermore, the abnormal uptake of thallium-201 returned to normal after treatment with corticosteroid. 201T1-SPECT was a useful tool for the evaluation of disease activity in the patient with hypertrophic pachymeningitis.