Comparison of Image Quality Between Conventional and Low-Dose Nonenhanced Head CT Export

@article{citeulike:2945576, abstract = {BACKGROUND AND PURPOSE: Increasing use of CT for evaluating neurologic disease may expose patients to considerable levels of ionizing radiation. We compared the image quality of low-mAs head CT scans with that of conventional nonenhanced scans. METHODS: Conventional head CT scans were obtained in 20 patients (all >65 years with history of non-CNS malignancy) by using a multidetector technique: 170 mA and 1-second scanning time (ie, 170 mAs), 140 kVp, table speed of 7.5 mm per rotation, pitch of 0.75, section thickness of 5 mm, and field of view of 25 mm. A limited volume helical data acquisition covering four 5-mm-thick images was obtained by using 90 mAs but otherwise the same parameters. Three neuroradiologists visually rated the resulting images for quality in a blinded comparison. Representative 1- to 4-mm2 regions of interest were chosen in gray matter and white matter locations. Conspicuity and the contrast-to-noise ratio were analyzed. Statistical comparisons were done by using the Student t test. RESULTS: Mean gray matter conspicuity was not significantly different between the 170- and 90-mAs groups (0.39 {+/-} 0.19 vs 0.41 {+/-} 0.03, P = .32). Mean gray matter contrast-to-noise ratio was approximately 22\% higher with 170 mAs than with 90 mAs (1.77 {+/-} 0.52 vs 1.39 {+/-} 0.38, P = .005). All 90-mAs images were rated as having slightly greater image noise than the 170-mAs scans but with sufficient perceived resolution. CONCLUSION: Although 90-mAs head CT images were moderately noisier than 170-mAs images, they were rated as having acceptable diagnostic quality.}, author = {Mullins, Mark E. and Lev, Michael H. and Bove, Peter and O'Reilly, Cara E. and Saini, Sanjay and Rhea, James T. and Thrall, James H. and Hunter, George J. and Hamberg, Leena M. and Gonzalez, Gilberto R.}, citeulike-article-id = {2945576}, citeulike-linkout-0 = {http://www.ajnr.org/cgi/content/abstract/25/4/533}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/15090337}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=15090337}, day = {1}, journal = {AJNR Am J Neuroradiol}, keywords = {brain, ct, head, multidetector, multislice}, month = {April}, number = {4}, pages = {533--538}, posted-at = {2008-06-30 18:52:52}, priority = {2}, title = {Comparison of Image Quality Between Conventional and Low-Dose Nonenhanced Head CT}, url = {http://www.ajnr.org/cgi/content/abstract/25/4/533}, volume = {25}, year = {2004} }

TY - JOUR ID - citeulike:2945576 L3 - citeulike-article-id:2945576 N2 - BACKGROUND AND PURPOSE: Increasing use of CT for evaluating neurologic disease may expose patients to considerable levels of ionizing radiation. We compared the image quality of low-mAs head CT scans with that of conventional nonenhanced scans. METHODS: Conventional head CT scans were obtained in 20 patients (all >65 years with history of non-CNS malignancy) by using a multidetector technique: 170 mA and 1-second scanning time (ie, 170 mAs), 140 kVp, table speed of 7.5 mm per rotation, pitch of 0.75, section thickness of 5 mm, and field of view of 25 mm. A limited volume helical data acquisition covering four 5-mm-thick images was obtained by using 90 mAs but otherwise the same parameters. Three neuroradiologists visually rated the resulting images for quality in a blinded comparison. Representative 1- to 4-mm2 regions of interest were chosen in gray matter and white matter locations. Conspicuity and the contrast-to-noise ratio were analyzed. Statistical comparisons were done by using the Student t test. RESULTS: Mean gray matter conspicuity was not significantly different between the 170- and 90-mAs groups (0.39 {+/-} 0.19 vs 0.41 {+/-} 0.03, P = .32). Mean gray matter contrast-to-noise ratio was approximately 22% higher with 170 mAs than with 90 mAs (1.77 {+/-} 0.52 vs 1.39 {+/-} 0.38, P = .005). All 90-mAs images were rated as having slightly greater image noise than the 170-mAs scans but with sufficient perceived resolution. CONCLUSION: Although 90-mAs head CT images were moderately noisier than 170-mAs images, they were rated as having acceptable diagnostic quality. IS - 4 JF - AJNR Am J Neuroradiol EP - 538 TI - Comparison of Image Quality Between Conventional and Low-Dose Nonenhanced Head CT VL - 25 SP - 533 KW - brain KW - ct KW - head KW - multidetector KW - multislice AU - Mullins, Mark AU - Lev, Michael AU - Bove, Peter AU - O'Reilly, Cara AU - Saini, Sanjay AU - Rhea, James AU - Thrall, James AU - Hunter, George AU - Hamberg, Leena AU - Gonzalez, Gilberto PY - 2004/04/01/ UR - http://www.ajnr.org/cgi/content/abstract/25/4/533 ER -