PT  - JOURNAL ARTICLE
AU  - B. Bodelle
AU  - E. Klein
AU  - N.N.N. Naguib
AU  - R.W. Bauer
AU  - J.M. Kerl
AU  - F. Al-Butmeh
AU  - J.L. Wichmann
AU  - H. Ackermann
AU  - T. Lehnert
AU  - T.J. Vogl
AU  - B. Schulz
TI  - Acute Intracranial Hemorrhage in CT: Benefits of Sinogram-Affirmed Iterative Reconstruction Techniques
AID  - 10.3174/ajnr.A3801
DP  - 2013 Dec 05
TA  - American Journal of Neuroradiology
4099  - http://www.ajnr.org/content/early/2013/12/05/ajnr.A3801.short
4100  - http://www.ajnr.org/content/early/2013/12/05/ajnr.A3801.full
AB  - BACKGROUND AND PURPOSE: Acute intracranial hemorrhage represents a severe and time critical pathology that requires precise and quick diagnosis, mainly by performing a CT scan. The purpose of this study was to compare image quality and intracranial hemorrhage conspicuity in brain CT with sinogram-affirmed iterative reconstruction and filtered back-projection reconstruction techniques at standard (340 mAs) and low-dose tube current levels (260 mAs). MATERIALS AND METHODS: A total of 94 consecutive patients with intracranial hemorrhage received CT scans either with standard or low-dose protocol by random assignment. Group 1 (n=54; mean age, 64 ± 20 years) received CT at 340 mAs, and group 2 (n=40; mean age, 57 ± 23 years) received CT at 260 mAs. Images of both groups were reconstructed with filtered back-projection reconstruction and 5 iterative strengths (S1–S5) and ranked blind by 2 radiologists for image quality and intracranial hemorrhage on a 5-point scale. Image noise, SNR, dose-length product (mGycm), and mean effective dose (mSv) were calculated. RESULTS: In both groups, image quality and intracranial hemorrhage conspicuity were rated subjectively with an excellent/good image quality. A higher strength of sinogram-affirmed iterative reconstruction showed an increase in image quality with a difference to filtered back-projection reconstruction (P < .05). Subjective rating showed the best score of image quality and intracranial hemorrhage conspicuity achieved through S3/S4–5. Objective analysis of image quality showed in an increase of SNR with a higher strength of sinogram-affirmed iterative reconstruction. Patients in group 2 (mean: 744 mGycm/1.71 mSv) were exposed to a significantly lower dose than those in group 1 (mean: 1045 mGycm/2.40 mSv, P < .01). CONCLUSIONS: S3 provides better image quality and visualization of intracranial hemorrhage in brain CT at 260 mAs. Dose reduction by almost one-third is possible without significant loss in diagnostic quality. Abbreviations DLPdose-length productFBPfiltered back-projection reconstructionHUHounsfield unitsICHintracranial hemorrhageSAFIREsinogram-affirmed iterative reconstruction