Susceptibility-weighted imaging in stroke-like migraine attacks after radiation therapy syndrome

Introduction: Stroke-like migraine attacks after radiation therapy (SMART) syndrome has a characteristic clinical presentation and postcontrast T1WI MRI appearance. Susceptibility-weighted imaging (SWI) may help distinguish SMART from other disorders that may have a similar postcontrast MRI appearance. Methods: The MRI examinations of four patients with SMART syndrome are described herein, each of which included SWI, FLAIR, DWI, and postcontrast T1WI on the presenting and follow-up MRI examinations. Results: In each, the initial SWI MRI demonstrated numerous susceptibility hypointensities <5 mm in size throughout the cerebrum, particularly within the periventricular white matter (PVWM), presumably related to radiation-induced cavernous hemangiomas (RICHs). By follow-up MRI, each postcontrast examination had demonstrated resolution of the gyriform enhancement on T1WI, without susceptibility hypointensities on SWI within those previously enhancing regions. Conclusion: These preliminary findings suggest that SWI may help identify SMART syndrome or at least help discriminate it from other disorders, by the findings of numerous susceptibility hypointensities on SWI likely representing RICHs, gyriform enhancement on T1WI, and postsurgical findings or appropriate clinical history.