Abstract Body: Introduction: Vertebrobasilar artery dissection (VBD) results from blood entering a tear in the intima of the vertebral artery (VA), basilar artery, and their branches. T1-Sampling Perfection with Application optimized Contrast using different flip angle Evolution (T1-SPACE) is valuable for detecting intramural hematoma (IMH). Despite the potential of susceptibility-weighted imaging (SWI) for IMH detection, its clinical adoption remains limited. This study aimed to clarify the usefulness of SWI and T1-SPACE in detecting IMH in VBD.
Methods: Consecutive patients admitted with symptomatic VBD within 28 days of initial symptom onset between November 2014 and September 2023 were retrospectively screened from the Jikei University School of Medicine Stroke Registry. The inclusion criteria were (1) definitive VBD diagnosis based on the Spontaneous Cervicocephalic Arterial Dissections Study criteria, and (2) performance of both SWI and T1-SPACE simultaneously. IMH on SWI was identified by (1) eccentric or concentric areas of hypointensity adjacent to the vessel wall, (2) hyperintensity on phase maps corresponding to hypointensity on SWI, and (3) absence of calcification on CT. We compared the IMH detectability between SWI and T1-SPACE.
Results: The study included 74 patients (52 males, median age 45). The 65 patients detected IMH on SWI, the 66 patients detected on T1-SPACE; IMH detection rates were equivalent (88% vs. 89%; p=1.00). T1-SPACE had a higher detection rate in VA dissection compared to PICA dissection (97 vs 14%, p<0.001). SWI showed no significant difference (VA, 88% vs PICA, 86%, p=0.613). SWI detected IMH more frequently in intracranial artery dissection compared to extracranial artery dissection (94% vs 38%, p<0.001), but T1-SPACE showed no significant difference (88% vs 100%, p=0.381).
Conclusions: IMH detectability on VBD is remarkable by SWI in PICA and T1-SPACE in extracranial artery. For the diagnosis of VBD, it is essential to perform both SWI and T1-SPACE.