Article Figures & Data
Figures
- Fig 1.
ICA identified components with time characteristics and spatial localization typical of arterial blood flow.
A, Images from the case of a 10-year-old male patient with thrombotic thrombocytopenic purpura and seizures. Examples of the spatial localization of components identified by ICA as arterial components are shown. Note that the signals identified correlate with the locations of large blood vessels in the sylvian fissure, interhemispheric fissure, and peri-mesencephalic cistern.
B, Examples of the spatial localization of components identified by ICA as arterial components in a 65-year-old female patient with left hemispheric border zone ischemia after embolization of a cavernous carotid aneurysm. Note the markedly reduced large vesssel flow components in the left hemisphere. Signals that correlate with the location of large blood vessels in the sylvian fissure, inter-hemispheric fissure, and peri-mesencephalic cistern were identified.
- Fig 2.
Normal rCBF maps of the 10-year-old male patient shown in Figure 1A.
A, Before ICA component removal.
B, After ICA component removal. Note the reduction in the arterial shine through that is the effect of large vessels confounding the tissue perfusion map. There is a subtle decrease in flow in the paramedian right parietal cortex.
- Fig 3.
rCBF maps of an 80-year-old female patient with large cell lymphoma of the right frontal lobe.
A, Before removal of arterial shine through.
B, After removal of arterial shine through using ICA. Reduction of arterial shine through improves definition of poorly perfused region..
Tables
Results of a blinded reading of the parametric maps of cerebral blood flow
Reader 1 Reader 2 Raw Mean (σ) ICA Mean (σ) P Raw Mean (σ) ICA Mean (σ) P Artifact severity 2.5(0.7) 1.3(1.1) <0.05 2.8(0.4) 1.0(0.9) <0.05 Image quality 1.1(0.5) 0.5(0.8) <0.05 1.3(0.5) 0.4(0.5) <0.05 Note.—ICA indicates independent component analysis. A Wilcoxon signed rank test comparing the severity of the artifact and image quality before (raw) and after (ICA) independent component removal of arterial components showed that component.
