Article Figures & Data
Figures
- Fig 1.
PET-CBF, CT-CBF, and CT-CBV images obtained in the five subjects. The CBF images of both PET and CT are displayed at the same window level. Note that large vessels on the brain surface are more prominent on CT-CBF than PET-CBF images. CT-CBV images were used for the VPE method.
- Fig 2.
Vascular maps and CT-CBF images obtained in subject 1 at various levels of VPE threshold. On the vascular maps, gray matter is displayed in green, and white matter in dark blue. The separation between gray matter and white matter was performed on the basis of the pixel attenuation on nonenhanced scans. Vascular pixels are expressed in red. The extent of the vascular area increases as the level of VPE threshold decreases. VPE threshold is indicated below the CT-CBF images. If the VPE threshold is very small (such as 5 mL/100 g), part of the brain parenchyma also disappears from the CT-CBF image.
- Fig 3.
Scatterplot of CT-CBF without VPE against PET-CBF and associated linear regression in subject 1. The slope is larger than 1.0, which suggests overestimation of CBF measured with perfusion CT. The correlation coefficient (r = 0.51) indicates moderate correlation.
- Fig 4.
Scatterplot of CT-CBF with VPE (threshold of 8 mL/100 g) against PET-CBF and associated linear regression in subject 1. The slope approaches 1.0, and the correlation coefficient (r = 0.69) increases compared with that without VPE.
- Fig 5.
Results of linear regression analysis obtained in subject 1 against various VPE thresholds. Values without VPE are plotted at the most right-hand side (threshold of 104 mL/100 g).
A, Correlation coefficient. As the VPE threshold decreases, the correlation coefficient increases. The best correlation is observed at a VPE threshold of 8 mL/100 g. Note that correlation coefficients rapidly decrease when VPE threshold is less than 8 mL/100 g.
B, Slope of linear regression. As the VPE threshold decreases, the slope also decreases and approaches 1.0. When the VPE threshold is less than 8 mL/100 g, the slope becomes less than 1.0.
C, Intercept of linear regression. As the VPE threshold decreases, the intercept increases and approaches zero.
- Fig 6.
Average CBF values of the whole section (pixels) with both CT and PET against varying VPE threshold values in subject 1. Without VPE (plotted at the most right-hand side, threshold of 104 mL/100 g), the CT-CBF value is higher than the PET value. CBF values with PET are almost constant despite the change in the VPE threshold. As the VPE threshold decreases, CBF values with CT decrease and approach the corresponding PET values. * indicates a statistically significant difference (P < .01)
- Fig 7.
Average CBF values of gray matter with both CT and PET against varying VPE threshold values in subject 1. Without VPE (plotted at the most right-hand side, threshold of 104 mL/100 g), the CT-CBF value is overestimated. As the VPE threshold decreases, CT-CBF values decrease and approach the corresponding PET values. * indicates a statistically significant difference (P < .01)
- Fig 8.
Average CBF values of white matter with both CT and PET against varying VPE threshold values in subject 1. Overestimation of CT-CBF is not observed. As the VPE threshold decreases, CT-CBF values decrease. * indicates a statistically significant difference (P < .01)
Tables
Subject No. VPE Threshold of the Best Correlation (mL/100g) Correlation Coefficient Slope Intercept Without VPE With VPE Without VPE With VPE Without VPE With VPE 1 8 0.51 0.69 1.55 1.05 −18.81 −7.91 2 8 0.52 0.65 2.65 1.55 −62.61 −26.36 3 6 0.38 0.63 1.27 1.02 −2.72 −3.38 4 8 0.37 0.62 1.69 1.25 −13.92 −10.43 5 8 0.44 0.65 1.58 1.00 −15.48 −3.33 Average 7.6 0.44 0.65 1.75 1.17 −22.71 −10.28 Subject No. Whole Section Gray Matter White Matter Without VPE With VPE Without VPE With VPE Without VPE With VPE PET CT PET CT PET CT PET CT PET CT PET CT 1 45.91 52.44* 46.20 40.70* 49.34 58.81* 50.02 47.69* 35.17 32.44 35.08 25.46* 2 46.73 61.30* 46.90 46.91 50.53 73.98* 51.05 55.65* 40.49 40.47 40.50 33.44* 3 49.20 59.85* 49.43 47.67 54.61 70.08* 55.03 57.60 39.53 41.59 38.76 28.72* 4 44.20 60.71* 44.57 46.36* 48.43 64.54* 48.75 53.81* 38.31 55.36* 37.64 33.97* 5 48.26 60.76* 48.73 47.80* 51.54 66.22* 52.02 50.73 37.50 42.80 37.32 30.34* Average 46.86 59.01 47.17 45.56 50.89 66.73 51.37 52.75 38.20 42.53 37.86 30.38 * Indicates a statistically significant difference (P < .01).
In this issue
Jump to section
Related Articles
Cited By...
- Prospective Multicenter Study of Changes in MTT after Aneurysmal SAH and Relationship to Delayed Cerebral Ischemia in Patients with Good- and Poor-Grade Admission Status
- Regional Comparison of Multiphase Computed Tomographic Angiography and Computed Tomographic Perfusion for Prediction of Tissue Fate in Ischemic Stroke
- Comparison of Perfusion CT Software to Predict the Final Infarct Volume After Thrombectomy
- Cerebral Perfusion Pressure is Maintained in Acute Intracerebral Hemorrhage: A CT Perfusion Study
- Imaging Evidence and Recommendations for Traumatic Brain Injury: Advanced Neuro- and Neurovascular Imaging Techniques
- Early Rate of Contrast Extravasation in Patients with Intracerebral Hemorrhage
- Recommendations for Imaging of Acute Ischemic Stroke: A Scientific Statement From the American Heart Association
- Avoiding "Pseudo-Reversibility" of CT-CBV Infarct Core Lesions in Acute Stroke Patients After Thrombolytic Therapy: The Need for Algorithmically "Delay-Corrected" CT Perfusion Map Postprocessing Software
- Theoretic Basis and Technical Implementations of CT Perfusion in Acute Ischemic Stroke, Part 2: Technical Implementations
- The Acetazolamide Challenge: Techniques and Applications in the Evaluation of Chronic Cerebral Ischemia
- Theoretic Basis and Technical Implementations of CT Perfusion in Acute Ischemic Stroke, Part 1: Theoretic Basis
- Tracer Delay-Insensitive Algorithm Can Improve Reliability of CT Perfusion Imaging for Cerebrovascular Steno-Occlusive Disease: Comparison with Quantitative Single-Photon Emission CT
- CT Perfusion Quantification of Small-Vessel Ischemic Severity
- CT Perfusion-Derived Mean Transit Time Predicts Early Mortality and Delayed Vasospasm after Experimental Subarachnoid Hemorrhage
- Serial Changes in CT Cerebral Blood Volume and Flow after 4 Hours of Middle Cerebral Occlusion in an Animal Model of Embolic Cerebral Ischemia
- Identification of the penumbra and infarct core on hyperacute noncontrast and perfusion CT
- Identification of Penumbra and Infarct in Acute Ischemic Stroke Using Computed Tomography Perfusion-Derived Blood Flow and Blood Volume Measurements
- Dynamic CT Perfusion Imaging in Subarachnoid Hemorrhage-Related Vasospasm
- Visual evaluation of perfusion computed tomography in acute stroke accurately estimates infarct volume and tissue viability
- Vasospasm after Subarachnoid Hemorrhage: Utility of Perfusion CT and CT Angiography on Diagnosis and Management
- Comparative Overview of Brain Perfusion Imaging Techniques
- Relationship between Brain Tissue Oxygen Tension and CT Perfusion: Feasibility and Initial Results
- Accuracy of Dynamic Perfusion CT with Deconvolution in Detecting Acute Hemispheric Stroke
- Brain Perfusion in Children: Evolution With Age Assessed by Quantitative Perfusion Computed Tomography
- Dynamic Perfusion CT: Optimizing the Temporal Resolution and Contrast Volume for Calculation of Perfusion CT Parameters in Stroke Patients