Diagnostic value of MRI in hypertrophic pachymeningitis

Objective 　To investigate the diagnostic value of MRI in hypertrophic pachymeningitis (HP). Methods 　MRI images of 11 patients with HP were analyzed retrospectively. The characteristic signs of the MRI images, and the relationship between the MRI features and pathology of HP were reviewed. Results 　In the 11 cases of HP, involvement of cerebral dura mater accounted for 8 cases, with spinal dura mater involvement in 2, both cerebral and spinal dura mater involvement in the other one case. The main sign of HP in MRI was an increased thickness of the dura mater, which showed iso-or hypointensity on T1WI without significant difference as compared with the brain parenchyma and spinal cord. The thickened dura mater showed obviously low signal on T2WI, and it was recognized easily as compared with the brain parenchyma and the spinal cord. On the DWI of 9 cases who had cerebral dura mater involvement, increased dura mater showed lower signal, but it was not so distinct as shown on T2WI. On the post-contrast T1WI, the thickened dura mater showed obvious enhancement, displaying better images than that of pre-enhancement image. Conclusion 　Among the different MRI techniques, T2-weighted imaging and post-enhanced T1WI have their advantages in the diagnosis of HP, and other MR imaging techniques could be complementary in increasing diagnostic accuracy and comprehensiveness. DOI: 10.11855/j.issn.0577-7402.2016.02.13