Significance of enhanced cerebral gray–white matter contrast at 80kVp compared to conventional 120kVp CT scan in the evaluation of acute stroke

Image quality and radiation dose of brain computed tomography in children: effects of decreasing tube voltage from 120 kVp to 80 kVp

“…As of March 4, 2015, the tube voltage for all non-enhanced brain CT scans in children was lowered from 120 kVp to 80 kVp at our institution, in accordance with the results of a study by Ben-David et al [9]. In August 2015, we retrospectively reviewed the picture archiving and communication system (PACS, Infinitt PACS; Infinitt Healthcare, Seoul, Korea) database for the period of March to May 2015, and searched for children who had undergone both 80-kVp and 120-kVp brain CT scans using the same CT scanner, with the two scans performed within 3 months of each other.…”

“…This is because the photoelectric component for gray matter is 4-6% higher than that of white matter and the gray matter attenuation is higher than the white matter attenuation at lower kVp, which can lead to an improved gray-white matter contrast-to-noise ratio using a low kVp CT scan [10,15]. In a recent study, BenDavid et al [9] demonstrated that unenhanced head CT scanning at a low tube voltage (80 kVp) delivers a higher gray matter-white matter contrast-to-noise ratio per dose compared to scans performed using a tube voltage of 120 kVp in adults. Similar to this previous study in adults, our study also revealed a statistically significant increase, from 2.18 to 2.35 (P=0.019), of gray matter-white matter contrast-to-noise ratio with 80-kVp CT. Another advantage of an 80-kVp over a 120-kVp brain CT scan in children was the reduction in radiation dose.…”

“…Furthermore, lowering CT tube voltage results in better softtissue contrast due to an increase of the photoelectric effect (versus Compton scattering) at lower X-ray photon energies. Unenhanced brain tissue represents an optimal tissue for the use of a lower tube voltage, since the photoelectric effect for gray matter is approximately 4-6% higher than that of white matter, which should theoretically result in gray matter yielding a greater increase in Hounsfield units than white matter [9,10]. Although a previous study has shown that non-enhanced brain CT scans at 80 kilo-voltage peak (kVp) delivers a high gray-white matter contrast-to-noise ratio compared to that obtained using a tube voltage of 120 kVp in adults [9], no study of the utility of 80-kVp non-enhanced brain CT scans in children has been conducted.…”

Methods of Reducing the Radiation Dose to the Pediatric Age Groups in Computed Tomography of Brain

“…In a recent study, Ben-David et al demonstrated that unenhanced head CT scanning at a low tube voltage (80 kVp) delivers a higher gray matter-white matter contrast-to-noise ratio per dose compared to scans performed using a tube voltage of 120 kVp in adults. Similar to this previous study in adults, our study also revealed a statistically significant increase, from 2.18 to 2.35 (P=0.019), of gray matter-white matter contrast-to-noise ratio with 80-kVp CT. 12 In a study by Ji Eun Park et al, a significant reduction in radiation dose was achieved with 120-kVp CT scans, whilst providing a similar overall image quality to that achieved with 120-kVp CT scans. The mean effective dose from 80-kVp CT scans was 6.5% lower than that observed for 120-kVp CT scans.…”

Creation of an anthropomorphic CT head phantom for verification of image segmentation

“…Table III compares the range and mean of measured HU in the phantom for acquisition ID C for both scanners with simulated values. 52 Additional data are taken from published studies of patient data; scanner A was a Phillips Brilliance 64-channel CT scanner at 120 kV and the maximum obtainable tube current, 53 scanner B was a GE Lightspeed VCT and Scanner C a GE Discovery CT750 HD both operating at 120 kV. 54 Additional values for the skull 52,55 and CSF 52 were also obtained.…”