Hiroyuki Tajiri, Presenter: Nothing to Disclose

Takahisa Mori, Abstract Co-Author: Nothing to Disclose

Tomonori Iwata, Abstract Co-Author: Nothing to Disclose

Yuichi Miyazaki, Abstract Co-Author: Nothing to Disclose

Masahito Nakazaki, Abstract Co-Author: Nothing to Disclose

The purpose of our retrospective study is to investigate whether or not susceptibility vessel sign of the basilar artery (SVS-BA) on T2*-weighted gradient echo images at 1.5T can predict clinical outcome after emergency endovascular treatment (EET) in patients where MRA suggests the BA occlusion.

Included for retrospective analysis were patients as follows, (1) study period was from November 2005 to December 2010, (2) who were admitted to our institution within 24 hours from stroke onset, (3) who underwent emergency MR imaging including DWI, T2*WI, MRA at 1.5T and symptomatic acute BAO was diagnosed by MRA, (4) whose NIHSS score on admission was 5 or more, and (5) who underwent EET. Excluded were patients (1) in whom DWIs showed extensive high signal intensity area in pons or cerebelli, (2) who had contraindications for EET. They were divided into two groups according to presence (group P) or absence (group A) of SVS-BA on T2*WI. The relationships between the presence of BA-SVS and patients’ baseline characteristics on admission (age, gender, stroke subtypes), onset to admission time (OTA time), onset to treatment time (OTT time), NIHSS on admission (NIHadm), NIHSS on the 7th day (NIH7th), modified Rankin Scale at 3 months (3M-mRS) and estimated lengths of BAO on emergency MRA (eMRA) were investigated. Estimated lengths of BAO were graded according to eMRA as follows: grade 4, no occlusion; grade 3, occluded distal AICA; grade 2, occluded distal union; grade 1: not visualized. TIMI grades 2 and 3 were defined as successful recanalization.

During the study periods, 25 patients were included for analysis. Successful recanalization was achieved in 16 patients (64%). In P (n=11) and A (n=14) groups, age (average) was 83 and 74 years (p=0.101), man (%) was 91 and 71 (p=0.341), cardiogenic (%) was 36 and 43 (p=1.000), OTA time(median: m) was 1.1 and 1.4 hrs (p=0.651), OTT time(m) was 5.2 and 5.6 hrs (p=0.791), NIHadm(m) was 31 and 19 (p=0.057) and BAO grade(m) was 2.0 and 3.0 (p<0.05), respectively. In P and A groups, successful recanalization rate (%) was 36 and 86 (p<0.01), NIH7th(m) was 28 and 6 (p<0.01), 3M-mRS(m) was 5.0 and 2.5 (p<0.05), respectively.

Clinical outcome following EET for the basilar artery occlusion was better in patients without SVS-BA on T2*WI than with SVS-BA.

The SVS-BA on T2*WI seems to be a significant predictor for no recanalization after EET.

Tajiri, H, Mori, T, Iwata, T, Miyazaki, Y, Nakazaki, M, Significance of Susceptibility Vessel Sign on T2 Star-weighted Images to Predict Clinical Outcome Following Emergency Endovascular Treatment in Patients with Acute Basilar Artery Occlusion.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034448.html