Intraindividual evaluation of the influence of iterative reconstruction and filter kernel on subjective and objective image quality in computed tomography of the brain

TY - JOUR

T1 - Intraindividual evaluation of the influence of iterative reconstruction and filter kernel on subjective and objective image quality in computed tomography of the brain

AU - Buhk, J H

AU - Laqmani, A

AU - von Schultzendorff, H C

AU - Hammerle, D

AU - Sehner, S

AU - Adam, G

AU - Fiehler, J

AU - Nagel, H D

AU - Regier, M

N1 - © Georg Thieme Verlag KG Stuttgart · New York.

PY - 2013/8

Y1 - 2013/8

N2 - OBJECTIVES: To intraindividually evaluate the potential of 4th generation iterative reconstruction (IR) on brain CT with regard to subjective and objective image quality.METHODS: 31 consecutive raw data sets of clinical routine native sequential brain CT scans were reconstructed with IR level 0 (= filtered back projection), 1, 3 and 4; 3 different brain filter kernels (smooth/standard/sharp) were applied respectively. Five independent radiologists with different levels of experience performed subjective image rating. Detailed ROI analysis of image contrast and noise was performed. Statistical analysis was carried out by applying a random intercept model.RESULTS: Subjective scores for the smooth and the standard kernels were best at low IR levels, but both, in particular the smooth kernel, scored inferior with an increasing IR level. The sharp kernel scored lowest at IR 0, while the scores substantially increased at high IR levels, reaching significantly best scores at IR 4. Objective measurements revealed an overall increase in contrast-to-noise ratio at higher IR levels, which was highest when applying the soft filter kernel. The absolute grey-white contrast decreased with an increasing IR level and was highest when applying the sharp filter kernel. All subjective effects were independent of the raters' experience and the patients' age and sex.CONCLUSION: Different combinations of IR level and filter kernel substantially influence subjective and objective image quality of brain CT.

AB - OBJECTIVES: To intraindividually evaluate the potential of 4th generation iterative reconstruction (IR) on brain CT with regard to subjective and objective image quality.METHODS: 31 consecutive raw data sets of clinical routine native sequential brain CT scans were reconstructed with IR level 0 (= filtered back projection), 1, 3 and 4; 3 different brain filter kernels (smooth/standard/sharp) were applied respectively. Five independent radiologists with different levels of experience performed subjective image rating. Detailed ROI analysis of image contrast and noise was performed. Statistical analysis was carried out by applying a random intercept model.RESULTS: Subjective scores for the smooth and the standard kernels were best at low IR levels, but both, in particular the smooth kernel, scored inferior with an increasing IR level. The sharp kernel scored lowest at IR 0, while the scores substantially increased at high IR levels, reaching significantly best scores at IR 4. Objective measurements revealed an overall increase in contrast-to-noise ratio at higher IR levels, which was highest when applying the soft filter kernel. The absolute grey-white contrast decreased with an increasing IR level and was highest when applying the sharp filter kernel. All subjective effects were independent of the raters' experience and the patients' age and sex.CONCLUSION: Different combinations of IR level and filter kernel substantially influence subjective and objective image quality of brain CT.

KW - Adult

KW - Aged

KW - Aged, 80 and over

KW - Artifacts

KW - Basal Ganglia Cerebrovascular Disease

KW - Brain

KW - Brain Diseases

KW - Brain Neoplasms

KW - Cerebral Cortex

KW - Cerebral Infarction

KW - Female

KW - Humans

KW - Image Enhancement

KW - Image Processing, Computer-Assisted

KW - Intracranial Hemorrhages

KW - Male

KW - Middle Aged

KW - Observer Variation

KW - Radiology Information Systems

KW - Reference Values

KW - Sensitivity and Specificity

KW - Skull Base

KW - Stroke

KW - Young Adult

U2 - 10.1055/s-0033-1335937

DO - 10.1055/s-0033-1335937

M3 - SCORING: Journal article

C2 - 23900941

VL - 185

SP - 741

EP - 748

JO - ROFO-FORTSCHR RONTG

JF - ROFO-FORTSCHR RONTG

SN - 1438-9029

IS - 8

ER -