Temporal similarity perfusion mapping: A standardized and model-free method for detecting perfusion deficits in stroke - Fig 6

<p>Panel A shows the inter-rater bias measures for TSP, TTP or MTT map-based lesion volumes. Panel B shows that the Pearson's correlation between TSP and TTP map-based lesion volumes was high (r(<i>18</i>) = 0.73, p<0.0003). Panel C shows that the effective CNR was greater for TSP (352.3) compared to TTP (p<0.03) and MTT maps (p<0.03).</p

Demographic and clinical characteristics of the study groups.

<p>Demographic and clinical characteristics of the study groups.</p

TSP maps in the 20 TIA imaging-negative patients.

<p>The TSP maps were uniform with values approaching 1.0 for the whole brain. The color scale for all TSP maps runs from <0 to 1, blue to red.</p

Example of the automated TSP maps in an ischemic stroke patient with a right-sided perfusion deficit.

<p>The images were generated using an iterative method that first calculated an average time-series of healthy tissue (top left) to generate a Pearson’s correlation map of all voxels in the brain based on correlation with the average time-series of healthy tissue (top right). Signal intensity time-series for voxels in healthy and under perfused tissue are in the bottom panel. Voxels in healthy tissue demonstrate a signal intensity time-series that is like the average signal intensity time-series for all healthy tissue, while a voxel in the perfusion deficit will have a signal intensity time-series that is delayed, dispersed and/or decreased.</p

Example of TSP maps with varying Pearson’s R correlation thresholds in a patient with a right-sided perfusion deficit.

<p>The red encircled map shows the threshold used for the automated lesion detection. No visual differences were found between TSP maps constructed with these different thresholds (B) Mean signal values for lesion and healthy tissue (based on the unbiased perfusion lesion) showed relatively stable TSP values within TSP maps for healthy and lesion tissue demonstrating robustness. (C) The mean difference in signal between healthy and perfusion tissue increased slightly (by ~0.03 in the 0.9 map compared to the 0.6 map) in TSP values.</p

Bland-Altman plots of the inter-rater reliability between the two readers for TSP, TTP and MTT map-based lesion volumes.

<p>Bland-Altman plots of the inter-rater reliability between the two readers for TSP, TTP and MTT map-based lesion volumes.</p

Figure comparing the spatial overlap between lesion volumes drawn on TSP and TTP maps for each patient.

<p>Overlap from lesion volumes from each rater was analyzed separately and averaged for each patient.</p