abdominal low-dose CT scans adapted with model-based iterative reconstruction method
What is it about?
PURPOSE: This study aims to introduce a novel low-dose abdominal computed tomography (CT) protocol adapted with model-based iterative reconstruction (MBIR).To validate the adaptability of this protocol, objective image quality and subjective clinical scores of low-dose MBIR images were compared with the normal-dose images. METHODS: 58 patients with normal-dose abdominal CT and 52 patients with low-dose abdominal CT scans were reconstructed with both conventional filtered back projection (FBP) and MBIR with/without smooth applying. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were used to compare the image quality between normal-dose and low-dose CT scans. CT dose index (CTDI) of normal and low dose abdominal CT images on post-contrast venous phase was also compared. RESULTS: SNR, CNR and clinical score of low-dose MBIR images all showed significant higher values (Bonferroni p<0.05) than those of normal-dose images with conventional FBP method. A total of around 40% radiation dose reduction (CTDI: 5.3 vs 8.7 mGy) could be achieved via our novel abdominal CT protocol. CONCLUSIONS: With the better SNR/CNR and clinical scores, the low-dose CT abdominal imaging protocol with MBIR could effectively reduce the radiation for patients and provide equal or even greater quality and also its adaptability in clinical abdominal diagnosis.
Why is it important?
Helical computed tomography has nowadays proven to be a versatile imaging technique in diagnostic imaging with its use rising exponentially in the decades. But the increase of Ionizing radiation to patients is also a serious clinical concern as the risk from stochastic effects is thought to increase with radiation dose. Therefore, radiologists/radiographers face the challenge of balancing image quality and radiation dose. In this article, we propose a novel abdominal CT protocol with low dose of Noise-Index 22 which is reconstructed with model-based iterative reconstruction (MBIR). Our results reveal all the SNR, CNR and clinical score are superior to those of high dose (Noise Index 15) reconstructed with filter back projection (FBP) method with 40% reduction of radiation dose on post-contrast venous abdominal CT images.