Ke Lin MD, Presenter: Nothing to Disclose

Meng Law MD, Abstract Co-Author: Nothing to Disclose

Otto Rapalino MD, Abstract Co-Author: Nothing to Disclose

James S. Babb PhD, Abstract Co-Author: Nothing to Disclose

Bidyut Kumar Pramanik MD, Abstract Co-Author: Nothing to Disclose

With increased permeability from a damaged blood-brain barrier, calculation of PCT-CBV may not be accurate, affecting the decision to thrombolyze. The Patlak-plot calculates permeability with an associated blood volume (Patlak-BV). The purpose was to compare Patlak-BV maps with conventional CBV maps in delineating the size of the infarct core in strokes with and without severe elevations in permeability.

PCT raw datasets of 20 patients who presented with acute non-lacunar strokes were used to retrospectively generate color maps of CBV and Patlak-BV from the same commercial software package. DWI was considered the standard reference for comparison. 2 readers manually outlined the region of low blood volume on each map through visual inspection while blinded to the DWI. Their results were averaged to give a single volume measurement per map per patient. DWI lesion volume was determined by hyperintensity >2SD of the mean intensity in the normal hemisphere. Infarcts were stratified according to severe elevation in permeability (>10mL/100g/min). Relative errors between color maps and DWI in each subset of strokes were compared using a mixed model regression analysis.

The mean +/- SD of relative errors for the Patlak-BV and CBV maps in strokes with severely elevated permeability (n=6) was 6.4% +/- 3.2% and 39% +/- 15% respectively and significantly different (p=0.0004). The rates of relative errors >20% compared to DWI between the two maps were also significantly different (p=0.0001) in favor of Patlak-BV. The mean +/- SD of relative errors for the Patlak-BV and CBV maps in strokes not meeting the selected permeability threshold (n=14) was 21% +/- 21% and 23% +/- 21% respectively and not significantly different (p=0.74).

Visual delineation of the infarct core on Patlak-BV maps gives significantly less relative error compared to conventional CBV maps in strokes with severely elevated permeability.

Patlak-BV rather than CBV should be used to define the infarct core in strokes with severe damage to the blood-brain barrier.

Lin, K, Law, M, Rapalino, O, Babb, J, Pramanik, B, Comparison of Cerebral Blood Volume and Patlak-based Blood Volume Maps in Delineating the Size of the Infarct Core in Strokes with and without Severely Elevated Microvascular Permeability.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5008406.html