William A. Mehan MD, MBA, Presenter: Nothing to Disclose

Jerrold Lee Boxerman MD, PhD, Abstract Co-Author: Nothing to Disclose

Jeffrey Michael Rogg MD, Abstract Co-Author: Nothing to Disclose

Richard Alan Haas MD, Abstract Co-Author: Nothing to Disclose

Mahesh V. Jayaraman MD, Abstract Co-Author: Nothing to Disclose

To determine whether CT perfusion (CTP) imaging influences the decision to administer intra-arterial (IA) therapy in patients presenting with acute stroke beyond the information available from non-contrast CT (NCCT), CT angiography (CTA) and knowledge of patients’ clinical National Institute of Health Stroke Scale (NIHSS) scores.

From September 2007 to 2009, 36 patients presenting with acute middle cerebral artery (MCA) territory stroke within 8 hours of symptom onset underwent NCCT, CTA, and CTP studies. Two neuroradiologists independently and by consensus reviewed NCCT, CTA and CTP data (CTP group). Two separate neuroradiologists independently and by consensus reviewed NCCT, CTA and NIHSS data (SS group). Patients were considered eligible for treatment if: there was an M1 or proximal M2 occlusion; the completed infarct (based on CTA source images (CTA-SI) or cerebral blood volume (CBV) maps) was less than 1/3 of the MCA territory; and estimated penumbra exceeded 120% of infarct core. Penumbra estimation was made by comparing CBV and mean transit time maps (CTP group), or CTA-SI with NIHSS (SS group). The SS group subsequently re-evaluated the patients once unblinded to the CTP data. Kappa values were calculated both within the two groups and between the consensus decisions of both groups. McNemar’s test was used to determine whether adding CTP data significantly affected SS group’s decisions.

Overall treatment decision by consensus was to offer IA therapy in 16/36 (44%) and 17/36 (47%) patients from the CTP and SS group, respectively. Intra-group Kappa scores were similar: 0.72 (SE 0.17) for the CTP group and 0.66 (SE 0.16) for the SS group. The Kappa score for inter-group consensus was 0.83 (SE 0.09). When unblinded to CTP, the SS group revised 2/36 (5.6%) decisions, which was insignificant using McNemar’s test (p=0.48).

The additional information from CT perfusion imaging does not significantly influence the decision to offer IA therapy in patients presenting with acute MCA stroke above and beyond NCCT, CTA, and NIHSS scores.  Further study into whether or not CT perfusion improves outcomes is warranted.

Reducing or eliminating the use of CT perfusion in an acute stroke management algorithm may have potential for cost savings and dose reduction.

Mehan, W, Boxerman, J, Rogg, J, Haas, R, Jayaraman, M, What Is the Added Value of CTP above CTA in Decision Making for Intra-Arterial Stroke Therapy?.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9011537.html