Article Figures & Data
Figures
- Fig 1.
The imaging plane for 5 ROIs: frontal white matter (ROI1), caudate nucleus (ROI2), lentiform nucleus (ROI3), thalamus (ROI4), and occipital white matter (ROI5).
- Fig 2.
CBV (A), CBF (B), and MTT (C) of lower dose CTP (tube current is 80 mAs, group B) in a 61-year-old man, 6 months after receiving a right carotid artery stent.
- Fig 3.
The mean SNR of individual ROIs in axial-enhanced imaging at Tmax reconstructed by IR and FBP in groups A and B (group A: 100 mAs with FBP; group A: 100 mAs with IR; group B: 80 mAs with FBP; group B: 80 mAs with IR. Asterisk indicates P value < .001).
- Fig 4.
The mean values of individual ROIs in CBV (A), CBF (B), and MTT (C) reconstructed by IR and FBP (x-axis: mean value of IR; y-axis: mean value of FBP).
- Fig 5.
The correlation SNR of individual regions of interest in CBV (A), CBF(B), and MTT (C) reconstructed by IR and FBP (x-axis: SNR of IR; y-axis: SNR of FBP).
Tables
- Table 1:
Patient characteristics and radiation dose in CT protocols with standard and low tube currents
Subject Characteristic Group A (Tube Current = 100 mAs) Group B (Tube Current = 80 mAs) P Value Age 74.9 74.2 .48 Sex (M/F) 14/6 14/6 1 Tmax (second) 12.5 + 2.34 12.3 + 2.83. .53 Maximium HU of A2a 159.84 177.6 .13 CTDI (mGy) 153.56 + 0.03 128.17 + 0.03 <.001 DLP (mGy/cm) 1229 + 0.26 985 + 0.6 <.001 Effective dose (mSv) 2.56 mSv 2.06 mSv <.001 Note:— Tmax indicates the time point of maximal enhancement of anterior cerebral artery; DLP, dose-length product.
↵a A2 indicates second portion of anterior cerebral artery.
- Table 2:
General linear regression of SNR in CBV, CBF, and MTT values among different tube currents, locations, reconstructive algorithms, and peak arterial and venous enhancement
SNR of CBF SNR of CBV SNR of MTT Standardized Estimate P Value Standardized Estimate P Value Standardized Estimate P Value 80 mAsa 0.043 .412 0.016 .747 −0.121 .031d IR reconstructionb −0.008 .872 0.002 .655 0.007 .887 Gray matterc 0.443 <.001d 0.515 <.001d −0.203 <.001d Peak enhancement of arterial ROI 0.055 .286 0.064 .195 −.178 .001d Peak enhancement of venous ROI 0.017 .754 0.043 .408 −0.163 .005d - Table 3:
Mean imaging score of CBV, CBF, and MTT reconstructed by IR and FBP in groups A and B
CBV Score CBF Score MTT Score IR Group A (100 mAs) 5.5 ± 1.7 4.2 + 2.0 3.5 ± 1.4 Group B (80 mAs) 5.5 ± 1.9 4.1 ± 2.1 3.5 ± 1.5 FBP Group A (100 mAs) 5.3 ± 1.8 3.6 ± 2.1 3.4 ± 1.5 Group B (80 mAs) 5.2 ± 1.9 3.6 ± 2.0 3.5 ± 1.4
