Cheemun Lum MD, Presenter: Nothing to Disclose

Jai Shankar, Abstract Co-Author: Nothing to Disclose

Ejaz Ahmed, Abstract Co-Author: Nothing to Disclose

Whole-brain CTP/CTA acquired during a single contrast bolus provides baseline perfusion parameters for future comparison when CTA is performed for evaluation of a suspected ruptured aneurysm. We sought to determine if there is a relationship between arterial diameter (AD) & perfusion in aSAH pts and to investigate if IA-therapy in symptomatic vasospasm(VS) results in improved perfusion (+ CBF, -MTT/TTP).

16 aSAH patients(6 pts VS treated with IA-milrinone) who had admission & f/u(d 4-14) whole-brain CTA/CTP using a single contrast bolus were studied. Sixty-two (31/side) automated ROIs placed at 6 levels were used to evaluate CBF, CBV, MTT, TTP at baseline & f/u. The perfusion parameters of pts with VS at baseline, start of VS & post-milrinone were compared. Intracranial ADs in the MCA, ACA, PCA were measured from the corresponding CTA. The Pearson correlation coefficient was used to assess AD vs change in perfusion, association of AD in a vascular territory vs perfusion change. A paired sample t-test was used to assess impaired perfusion from baseline & response to therapy in pts with VS.  

Overall, 38 CTP/CTA studies were evaluated. There was correlation between AD, MTT(r=-0.58,p=0.018) & TTP(r=-0.54, p=0.031), suggesting progressive arterial narrowing is associated with prolonged MTT & TTP. For VS pts, there was correlation(r=-0.8) between AD & TTP(p=0.05), suggesting pts with narrowing & VS have prolonged TTP. For pts without VS, there was correlation(r=-0.76) between AD & MTT (p=0.01). Significantly prolonged MTT in the MCA territory(M1, M2, MCA/PCA) was associated with M1, M2 narrowing(r=-0.71, p=0.002).For the ACA, there was association of prolonged TTP with A1/A2 narrowing(r=-0.54,p=0.029). VS patients treated with IA-therapy showed decrease in MTT((p=0.02) suggesting improved perfusion. There were trends to improved CBF(p=0.07) and TTP(p=0.07) with IA-therapy.

In patients with aSAH, arterial narrowing is associated with decreased perfusion (MTT/TTP) from baseline. In the MCA & ACA territories, MTT & TTP changes in perfusion are correlated with AD. There is a treatment response(decreased MTT) in VS pts treated with IA-milrinone. A larger, prospective study is necessary to determine the most appropriate perfusion parameter to follow.

Serial changes in perfusion compared to baseline can aid management of aSAH pts with impaired LOC and suspected vasospasm.

Lum, C, Shankar, J, Ahmed, E, Whole-Brain CT Perfusion for the Evaluation of Vasospasm in Aneurysmal Subarachnoid Haemorrhage (aSAH): A Preliminary Investigation Evaluating Relationship between Arterial Diameter and Perfusion Changes Following Intraarterial Therapy.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9009244.html