Perivascular Space Imaging at Ultrahigh Field MR Imaging

Current results show that imaging PVS at UHF is feasible and offers the possibility of accurately identifying and quantitation of the PVS, including those smaller in size (<1 mm), which are usually not visible on conventional lower field MR imaging scans. This may be particularly helpful in analyzing the normal PVS and the early pathologic alterations of PVS. More studies, both in clinical and research settings, are required to investigate the advantages of UHF for in vivo PVS analysis, and this will allow further investigation into the physiologic function of PVS in terms of cerebrospinalinterstitial fluid exchange, lymphatic and brain clearance system, as well as their role as a diagnostic biomarker for some neurologic diseases. Moreover, further efforts are needed to solve the existing limitations of imaging at UHF, including both those related to sequence optimization and hardware development and those concerning SAR limitations and the safety of subjects and patients. Nonetheless, the more widespread application of UHF MR imaging systems is expected to result in novel scientific discoveries and more opportunities to use 7 T MR imaging scanners as diagnostic tools in clinics, with subsequent anticipated improvement of the clinical outcomes of patients.