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Acute intracranial hemorrhage in CT: benefits of sinogram-affirmed iterative reconstruction techniques
B Bodelle1, E Klein, N N N Naguib
1From the Departments of Diagnostic and Interventional Radiology (B.B., E.K., N.N.N.N., R.W.B., J.M.K., F.A.-B., J.L.W., T.L., T.J.V., B.S.).
Insights
Sinogram-affirmed iterative reconstruction (SAIR) improves brain CT image quality for detecting intracranial hemorrhage. This technique allows for nearly one-third dose reduction without compromising diagnostic accuracy.
Area of Science:
- Radiology
- Medical Imaging
- Neuroradiology
Background:
- Acute intracranial hemorrhage is a critical condition requiring rapid CT diagnosis.
- CT scans are essential for precise and timely diagnosis of intracranial hemorrhage.
- Evaluating advanced reconstruction techniques is crucial for optimizing CT protocols.
Purpose of the Study:
- To compare image quality and intracranial hemorrhage conspicuity.
- To evaluate sinogram-affirmed iterative reconstruction (SAIR) versus filtered back-projection (FBP).
- To assess standard (340 mAs) and low-dose (260 mAs) CT protocols.
Main Methods:
- 94 patients with intracranial hemorrhage underwent CT scans.
- Scans were performed using standard (340 mAs) or low-dose (260 mAs) protocols.
- Images were reconstructed using FBP and SAIR (S1-S5) and evaluated by radiologists.
Main Results:
- SAIR demonstrated increased image quality and intracranial hemorrhage conspicuity compared to FBP (P < .05).
- Optimal subjective ratings for image quality and conspicuity were achieved with SAIR strengths S3/S4-5.
- Low-dose CT (260 mAs) resulted in significantly lower radiation exposure (1.71 mSv) than standard-dose CT (2.40 mSv, P < .01).
Conclusions:
- SAIR strength S3 offers superior image quality and intracranial hemorrhage visualization at 260 mAs.
- Significant radiation dose reduction (nearly one-third) is achievable without sacrificing diagnostic quality.
- SAIR is a promising technique for low-dose brain CT in acute intracranial hemorrhage detection.
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.
