Sotirios Bisdas MD, Presenter: Nothing to Disclose

Jessen Gurung MD, Abstract Co-Author: Nothing to Disclose

Frank Donnerstag, Abstract Co-Author: Nothing to Disclose

Choon Hua Thng MBBS, Abstract Co-Author: Nothing to Disclose

Martin Georg Mack MD, Abstract Co-Author: Nothing to Disclose

Tong San Koh PhD, Abstract Co-Author: Nothing to Disclose

Thomas Josef Vogl MD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

To evaluate the accuracy of perfusion CT (PCT) measurements and the delineation of the lesion volume with regard to arterial input function (AIF) selection in patients with acute stroke.

28 consecutive patients with acute stroke in the middle cerebral artery (MCA)territory underwent PCT. Follow-up MRI was obtained in all patients after 4.7 days. PCT maps were generated using the anterior cerebral artery (ACA), and branches of the MCA ipsilateral and contralateral to the ischemia as AIF. Infarct, penumbra, and total ischemic lesion (infarct plus penumbra) were delineated on cerebral blood flow (CBF) maps using a three-color scale. CBF, cerebral blood volume (CBV), mean transit time (MTT), and volume of these 3 regions were calculated.

The CBF, CBV, and MTT values in the infarct using the ACA as AIF were 8.38±2.5, 1.75±0.72,18.93±3.62, respectively; using the ipsilateral MCA as AIF were 8.1±2.04, 1.45±0.74, 16.31±4.81, respectively; using the contralateral MCA as AIF were 8.09±2.01,1.69±0.66, 18.26±3.38, respectively.The CBF and CBV values obtained by the different AIFs in the infarct, penumbra, and total ischemic lesions were significantly correlated (r=0.94-0.97, p≤0.01). Only the MTT values in the infarct were correlated (r=0.87-0.91, p<0.05) between the different AIFs. High correlation coefficients (r=0.81-0.90, p<0.001) were found between the infarct and total ischemic volumes and the MRI follow-up infarct volume. ACA as AIF provided the best correlations (r=0.91, P=0.0002) with the follow-up measurements. No statistically significant difference was found between the three different AIF-estimated admission total ischemic volumes and the follow-up infarct volume.

The AIF selection ipsilateral or contralateral to the ischemic area has no statistically significant impact on the calculation of the CBF, CBV values, and the infarct volume estimation in stroke patients. Standardization of PCT post-processing using the ACA as AIF is strongly recommended.

The AIF selection in the cerebral perfusion CT is important and this abstract shows that the AIF can be selected independently of the ischemia site.

Bisdas, S, Gurung, J, Donnerstag, F, Thng, C, Mack, M, Koh, T, Vogl, T, et al, , et al, , The Influence of Arterial Input Function Site on the Measured Perfusion Values and Infarct Volumetric in Patients with Acute Stroke Evaluated by Perfusion CT.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5008723.html