Effects of radiation dose reduction in Volume Perfusion CT imaging of acute ischemic stroke
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To examine the influence of radiation dose reduction on image quality and sensitivity of Volume Perfusion CT (VPCT) maps regarding the detection of ischemic brain lesions.
Methods and materials
VPCT data of 20 patients with suspected ischemic stroke acquired at 80 kV and 180 mAs were included. Using realistic reduced-dose simulation, low-dose VPCT datasets with 144 mAs, 108 mAs, 72 mAs and 36 mAs (80 %, 60 %, 40 % and 20 % of the original levels) were generated, resulting in a total of 100 datasets. Perfusion maps were created and signal-to-noise-ratio (SNR) measurements were performed. Qualitative analyses were conducted by two blinded readers, who also assessed the presence/absence of ischemic lesions and scored CBV and CBF maps using a modified ASPECTS-score.
SNR of all low-dose datasets were significantly lower than those of the original datasets (p < .05). All datasets down to 72 mAs (40 %) yielded sufficient image quality and high sensitivity with excellent inter-observer-agreements, whereas 36 mAs datasets (20 %) yielded poor image quality in 15 % of the cases with lower sensitivity and inter-observer-agreements.
Low-dose VPCT using decreased tube currents down to 72 mAs (40 % of original radiation dose) produces sufficient perfusion maps for the detection of ischemic brain lesions.
• Perfusion CT is highly accurate for the detection of ischemic brain lesions
• Perfusion CT results in high radiation exposure, therefore low-dose protocols are required
• Reduction of tube current down to 72 mAs produces sufficient perfusion maps
KeywordsLow dose perfusion CT, Perfusion CT, Perfusion imaging, Radiation dose Stroke
Anterior cerebral artery
Cerebral blood flow
Cerebral blood volume
- LD VPCT
Low-dose volume perfusion CT
Middle cerebral artery
Mean transit time
Posterior cerebral artery
Region of interest
Tissue at risk
Volume perfusion CT
The scientific guarantor of this publication is Professor Dr. Martin Wiesmann. The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article. The authors state that this work has not received any funding. One of the authors (Ahmed Othman) has significant statistical expertise. Institutional Review Board approval was received and the Institutional Review Board waived the requirement for informed patient consent. Approval from the institutional animal care committee was not required because the study was conducted on Patient data. Methodology: retrospective, diagnostic or prognostic, multicenter study.