Effects of radiation dose reduction in Volume Perfusion CT imaging of acute ischemic stroke

• Published in: European radiology 2015-12, Vol.25 (12), p.3415-3422
• Main Authors: Othman, Ahmed E., Brockmann, Carolin, Yang, Zepa, Kim, Changwon, Afat, Saif, Pjontek, Rastislav, Nikobashman, Omid, Brockmann, Marc A., Kim, Jong Hyo, Wiesmann, Martin
• Format: Article
• Language: English
• Subjects: Aged; Blood; Brain - blood supply; Brain - diagnostic imaging; Cone-Beam Computed Tomography - methods; Datasets; Diagnostic Radiology; Female; Hospitals; Humans; Imaging; Internal Medicine; Interventional Radiology; Ischemia; Male; Medical imaging; Medicine; Medicine & Public Health; Neuro; Neuroradiology; Observer Variation; Patients; Radiation; Radiation Dosage; Radiology; Reproducibility of Results; Retrospective Studies; Sensitivity and Specificity; Signal-To-Noise Ratio; Simulation; Stroke; Stroke - diagnostic imaging; Ultrasound
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-015-3763-7

Purpose 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. Results SNR of all low-dose datasets were significantly lower than those of the original datasets (p