Comparison of image quality and radiation dose using different pre-ASiR-V and post-ASiR-V levels in coronary computed tomography angiography

Abstract

OBJECTIVE:

To determine the optimal pre-adaptive and post-adaptive level statistical iterative reconstruction V (ASiR-V) for improving image quality and reducing radiation dose in coronary computed tomography angiography (CCTA).

METHODS:

The study was divided into two parts. In part I, 150 patients for CCTA were prospectively enrolled and randomly divided into 5 groups (A, B, C, D, and E) with progressive scanning from 40% to 80% pre-ASiR-V with 10% intervals and reconstructing with 70% post-ASiR-V. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Subjective image quality was assessed using a 5-point scale. The CT dose index volume (CTDI_vol) and dose-length product (DLP) of each patient were recorded and the effective radiation dose (ED) was calculated after statistical analysis by optimizing for the best pre-ASiR-V value with the lowest radiation dose while maintaining overall image quality. In part II, the images were reconstructed with the recommended optimal pre-ASiR-V values in part I (D group) and 40%–90% of post-ASiR-V. The reconstruction group (D group) was divided into 6 subgroups (interval 10%, D0:40% post-ASiR-V, D1:50% post - ASiR-V, D2:60% post-ASiR-V, D3:70% post-ASiR-V, D4:80% post-ASiR-V, and D5:90% post-ASiR-V).The SNR and CNR of D0-D5 subgroups were calculated and analyzed using one-way analysis of variance, and the consistency of the subjective scores used the k test.

RESULTS:

There was no significant difference in the SNRs, CNRs, and image quality scores among A, B, C, and D groups (P > 0.05). The SNR, CNR, and image quality scores of the E group were lower than those of the A, B, C, and D groups (P < 0.05). The mean EDs in the B, C, and D groups were reduced by 7.01%, 13.37%, and 18.87%, respectively, when compared with that of the A group. The SNR and CNR of the D4–D5 subgroups were higher than the D0-D3 subgroups, and the image quality scores of the D4 subgroups were higher than the other subgroups (P < 0.05).

CONCLUSION:

The wide-detector combined with 70% pre-ASiR-V and 80% post-ASiR-V significantly reduces the radiation dose of CCTA while maintaining overall image quality as compared with the manufacture’s recommendation of 40% pre-ASiR-V.

Keywords

Pre-ASiR-V Post-ASiR-V CCTA radiation dose image quality

1 Introduction

In recent years, the risk factors of cardiovascular diseases show an obvious increase trend. Coronary heart disease has become a major disease threatening human health, and the prevalence of hypertension, obesity, dyslipidemia and other diseases in the population has increased, which are the main influencing factors of coronary heart disease. CCTA is the main method to evaluate the anatomic course, lesion extent and cumulative range of coronary arteries [1, 2]. As a non-invasive imaging technology, with the improvement of imaging success rate and image quality, its clinical application has become more and more extensive, and it can even be used as a physical examination item. However, CCTA also has some limitations, especially the high ionizing radiation that patients are exposed to [3, 4]. Therefore, it is a problem that radiologists must consider to reasonably reduce the radiation dose in CCTA examination [5, 6]. Traditional methods to reduce the radiation dose of CCTA include lowering the tube voltage and the use of tube current automatic modulation technology [7 –9]. However, the reduction of tube voltage and tube current not only reduces the radiation dose, but also increases the image noise and may have a negative impact on image quality [10, 11].

In order to collect the image quality satisfying the diagnosis at low radiation dose, the CT manufactures have developed a series of reconstruction algorithms [12, 13]. For example, ASiR, MBIR and ASiR-V for the CT scanner used in our study. ASiR-V is widely used because of its high efficiency and obvious noise reduction effect. ASiR-V eliminates the most time-consuming optical model in MBIR and focuses on noise model, physical model and object model in the reconstruction process [14], which is mainly used to reduce noise, artifacts and improve low-density resolution of reconstructed images. There are two modes in ASiR-V: pre-ASiR-V and post-ASiR-V. The pre-ASiR-V can be used to reduce radiation dose, and the post-ASiR-V can be used to reduce image noise and improve image quality. The two modes have ten levels each to choose from, and each level has different effects.

The purpose of our study was therefore to characterize the impact of different percentages of pre-ASiR-V and post-ASiR-V on image quality and radiation dose during CCTA examinations, and to optimize the percentages of pre-ASiR-V and post-ASiR-V, without affecting the quality of the clinical diagnosis.

2 Methods and materials

2.1 Patient population

This study was approved by our institutional review board, and written informed consent was obtained by all patients. We prospectively enrolled 150 patients (mean age: 53.67±5.33 years, range: 39–79 years; body mass index: 25.3±2.51 kg/m²; 71 females and 79 males) who underwent CCTA from June to December of 2019. Clinical exclusion criteria included allergy to iodine contrast, pregnancy, heart failure, kidney failure and metal implants in the scanning region. All patients were randomly divided into five groups (A, B, C, D, and E), with 30 patients in each group (Table 1).

Table 1
The comparison of patient characteristics, Objective image quality evaluation and ED among the five groups

Parameters A B C D E P value

BMI (kg/m2) 25.79±3.20 25.43±2.10 25.61±3.37 25.62±2.70 25.63±2.73 0.411

Age (Year) 58.21±10.63 65.70±12.94 58.70±11.57 62.90±11.09 60.48±10.54 0.150

SD 28.18±1.89 28.21±2.11 28.37±1.90 28.78±1.84 30.35±1.47 0.00

SNR 18.91±1.04 18.73±0.99 18.58±1.45 18.36±1.32 17.49±0.88 0.00

CNR 15.39±0.88 15.34±0.81 14.98±1.29 14.87±1.00 14.27±0.78 0.00

ED (mSv) 15.26±0.42 14.19±0.49 13.22±0.48 12.38±0.60 11.25±0.46 0.00

Parameters	A	B	C	D	E	P value
BMI (kg/m2)	25.79±3.20	25.43±2.10	25.61±3.37	25.62±2.70	25.63±2.73	0.411
Age (Year)	58.21±10.63	65.70±12.94	58.70±11.57	62.90±11.09	60.48±10.54	0.150
SD	28.18±1.89	28.21±2.11	28.37±1.90	28.78±1.84	30.35±1.47	0.00
SNR	18.91±1.04	18.73±0.99	18.58±1.45	18.36±1.32	17.49±0.88	0.00
CNR	15.39±0.88	15.34±0.81	14.98±1.29	14.87±1.00	14.27±0.78	0.00
ED (mSv)	15.26±0.42	14.19±0.49	13.22±0.48	12.38±0.60	11.25±0.46	0.00

2.2 CT protocol

The study was divided into two parts. In part I, the patients of groups A, B, C, D, and E were treated with progressive scanning from 40% to 80% pre-ASiR-V with 10% intervals, reconstructed with 70% post-ASiR-V, and optimized for the best pre-ASiR-V value with the lowest radiation dose while maintaining overall image quality.In part II, the images were reconstructed with the recommended optimal pre-ASiR-V value from part I (D group), and 40%–90% of post-ASiR-V. The reconstruction group (Dgroup) was divided into six subgroups (interval 10%, D0:40% post-ASiR-V, D1:50% post-ASiR-V, D2:60% post-ASiR-V, D3:70% post-ASiR-V, D4:80% post-ASiR-V, and D5:90% post-ASiR-V).

All patients were analyzed using the Revolution CT scanner (GE Healthcare, Waukesha, WI, USA). All patients were in the supine position with their hands on top of their heads. Breathing techniques were explained and practiced with the patient before the patients in groups A–E were scanned using pre-ASiR-V from 40% to 80% with 10% ASiR-V intervals. The scan mode was cardiac. The parameters were as follows: the tube voltage was 120 kVp, a three-dimensional Smart mA modulation technique was used, the mA ranged from 150 mA to 700 mA, the Gantry rotation time was 0.28 s, the noise index was 9 at a thickness of 2.5 cm, and the scan field of view was 19.2 cm.

For patients with a stable heart rate (<70 beats/min), acquisition of the ECG phase of the CCTA scan protocol was set to a 75% R-R interval, if the heart rate of patients was between 70–85 beats/min, the scan protocol was set to 30%–50% R-R intervals. When the heart rate exceeded 90 beats/min or there was arrhythmia, 40%–95% R-R intervals were used. The contrast medium (Iopamidol, 370 mg/mL, Bracco, Munroe Township, NJ, USA) was injected at 5.5 mL/s into the right antecubital vein (median volume: 53 mL; range: 45–67 mL), followed by a saline flush (40 mL) at the same rate using a high pressure injector (Missouri XD2001; Ulrich, Ulm, Germany). Bolus-tracking technology was used, and the region of interest (ROI: 6 mm²) was placed in the center of the ascending aorta with a threshold value of 280 Hounsfield units and a 2 s delay. The scan range was from 120 mm–160 mm below the tracheal carina to 0.5 cm from the bottom of the heart.

2.3 Objective image quality evaluation

All images were transferred to the GE AW4.7 workstation for analyses and measurements. The ROI (5 mm²) was placed at the root of the aorta, the left coronary artery, the right coronary artery, and the chest wall musculature at the same level. The clone function of comparison was adopted to ensure the consistency of size and shape of the ROI. The CT attenuation value and Standard Deviation (SD) of each ROI was measured. The mean CT attenuation values and mean SD values from three blood vessels were respectively calculated as CT1 and SD1, we used the value from the chest wall as the CT2 and SD2, with the following calculations: SNR (SNR = CT1/SD1) and CNR (CNR = [CT1-CT2]/SD1) [15, 16].

2.4 Subjective image quality evaluation

All images were assessed independently with a five-grade scale [17] by two cardiac radiologists who had 10 years of experience in CCTA, and who were blinded to the CT scan parameters. Image scores≥3 were considered to be in accordance with the diagnostic requirements. The scoring criteria are shown in Table 2.

Table 2
Grading score for qualitative image analysis

Scale Image qualitative Image noise Vessel contrast Diagnostic confidence

5 Excellent image quality Minimal or no noise Sharpest visibility(4nd-order branches or higher) Fully diagnostic

4 Good image quality Common or below-average noise Better than average visibility(3nd-order branches) Good diagnostic

3 Standard image quality Average noise Average visibility(2nd-order branches) Diagnostic

2 Low image qualitative Above-average noise Suboptimal overall visibility(main or 1 st-order branches) Affecting diagnosis

1 Unacceptable image qualitative Unacceptable noise Unacceptable visibility(vessels not seen) Non-diagnostic

Scale	Image qualitative	Image noise	Vessel contrast	Diagnostic confidence
5	Excellent image quality	Minimal or no noise	Sharpest visibility(4nd-order branches or higher)	Fully diagnostic
4	Good image quality	Common or below-average noise	Better than average visibility(3nd-order branches)	Good diagnostic
3	Standard image quality	Average noise	Average visibility(2nd-order branches)	Diagnostic
2	Low image qualitative	Above-average noise	Suboptimal overall visibility(main or 1 st-order branches)	Affecting diagnosis
1	Unacceptable image qualitative	Unacceptable noise	Unacceptable visibility(vessels not seen)	Non-diagnostic

2.5 Radiation dose

The CTDI_vol and DLP were recorded from the CT, and the ED was calculated using the formula: ED = DLP×K, where K represented the radiological protection conversion factor, which was the adult heart (chest) K = 0.026 mSv·mGy-1cm-1 [18].

2.6 Statistical analyses

All quantitative data were analyzed with SPSS statistical software for Windows, version 21.0 (SPSS, Chicago, IL, USA) and variables are expressed as the mean±standard deviation (SD). One-way analysis of variance was used to compare the difference among each group (A-E groups) and each subgroup (D0-D5 subgroups). The variables were as follows: patient age, body mass index (BMI), image noise, CT attention, SNR, CNR, and radiation dose. The k test was used to analyze the consistency of subjective scores for image qualities between the two radiologists (the range of k values: poor: 0–0.2, average: 0.21–0.40, medium: 0.41–0.60, good: 0.61–0.80, and excellent: 0.8–1.0). A value of P < 0.05 was considered statistically significant.

3 Results

3.1 The general situation

All patients completed the CCTA examination successfully. The results of our study showed that there was no significance difference in patient age (P = 0.150) and BMI among the five groups (P = 0.411) as shown in Table 1.

3.2 Quantitative image analysis

Part I: There was no significant difference in SNR and CNR among the groups A, B, C, and D (SNR: 18.91±1.04, 18.73±0.99, 18.58±1.45, and 18.36±1.32, respectively; and CNR: 15.39±0.88, 15.34±0.81, 14.98±1.29, and 14.87±1.00, respectively; P > 0.05). The SNRs and CNRs of group E were lower than those in groups A, B, C, and D (P < 0.001) as shown in Table 2, Fig. 1, and Fig. 2. For all groups, the SNR and CNR had a negative correlation with the pre-ASiR-V level. The correlation coefficients were as follows: SNR r=–0.445 (P < 0.001), CNR r=–0.415 (P < 0.001). The image noise values and CT values had a positive correlation with the pre-ASiR-V level. The correlation coefficients were as follows: Image noise r = 0.405 (P < 0.001), CT values r = 0.207 (P = 0.012). Part II: The SNRs of D0–D5 were 20.08±3.92, 21.02±4.31, 22.15±4.30, 19.17±4.27, 24.89±5.38, and 26.51±5.71, respectively; and the CNRs of D0–D5 were 15.62±3.51, 16.41±3.84, 17.28±3.80, 14.96±3.82, 19.41±4.90, and 19.43±4.65, respectively. The SNRs and CNRs of the D4 and D5 subgroups were higher than the other subgroups (D0–D3, P < 0.05) as shown in Table 3 and Fig. 3. For all subgroups, the SNR and CNR had a positive correlation with the post-ASiR-V level, the image noise values had a negative correlation with the post-ASiR-V level, CT values had no correlations with the post-ASiR-V level. The correlation coefficients were as follows: SNR r = 0.318 (P < 0.001), CNR r = 0.318 (P < 0.001), image noise r=–0.342 (P < 0.001), CT values r = 0.025(P = 0.773).

Fig.1

Coronary computed tomography angiography (CCTA) images acquired by the wide-detector combined with different percentages of pre-ASiR-V. The images were scanned with 40% pre-ASiR-V(a), 50% pre-ASiR-V(b), 60% pre-ASiR-V(c), 70% pre-ASiR-V(d), and 80% pre-ASiR-V(e) and reconstructed with 70% post-ASiR-V. The CNR of images (a–e) were 15.35, 15.40, 14.99, 15.29, and 14.34, respectively. The subjective scores of images (a–e) were 3.59, 3.66, 3.73, 3.79, and 3.21, respectively. The effective doses of the patients (a–e) were 8.21, 7.64, 7.15, 6.67, and 6.06 mSv, respectively.

Fig.2

Graph showing the comparisons of SNR, CNR, and ED among different percentages of pre-ASiR-V. Group E showed a lower SNR and CNR than did groups A, B, and C (all P < 0.05) in all patients, whereas there was no statistically significant difference among groups A, B, C, and D ineither SNR (P = 0.000) or CNR (P = 0.000). There were significant differences in ED among groups A, B, C, and D (P = 0.000). Compared with group A, the EDs in groups B, C, and D decreased by 7.01%, 13.37%, and 18.87%, respectively.

Table 3

The comparison of objective parameters and subjective image quality with different post-ASiR-V levels

Group	SNR	CNR	Image quality score
D0	20.08±3.92	15.62±3.51	3.50±0.71
D1	21.02±4.31	16.41±3.84	3.70±0.68
D2	22.15±4.30	17.28±3.80	3.80±0.75
D3	19.17±4.27	14.96±3.82	3.83±0.69
D4	24.89±5.38	19.41±4.90	4.09±0.83
D5	26.51±5.71	19.43±4.65	3.72±0.51
P Value	0.00	0.00	0.00
F Value	11.163	11.002	205.378

Fig.3

Coronary computed tomography angiography (CCTA) images acquired by different post-ASiR-V levels based on a 56-year-old male patient with a body mass index of 25.7 kg/m². The CCTA images were scanned using 70% pre-ASiR-V combined with 40% post-ASiR-V (A), 50% post-ASiR-V (B), 60% post-ASiR-V (C), 70% post-ASiR-V (D), 80% post-ASiR-V (E), and 90% post-ASiR-V (F). With the percentage of post-ASiR-V increasing, the image noise decreased, but the computed tomography value did not significantly change. The subjective scores of images (A–F) were 3.42, 3.59, 3.64, 3.79, 3.98, and 3.57, respectively. Figure E had the highest score. Images a-f were the LAD images of the same patient with a 70% pre-ASiR-V level combined with 40% post-ASiR-V (A), 50% post-ASiR-V (B), 60% post- ASiR-V (C), 70% post-ASiR-V (D), 80% post-ASiR-V (E), and 90% post-ASiR-V(F). Compared with the other images, the image quality of e (80% post-ASiR-V) was higher than that of a, b, c, d, and f.

3.3 Subjective image analysis

All images were assessed by two radiologists who had a good subjective consistency (k = 0.79). Part I: There was no significant statistical difference in scores of the subjective image qualities among the four groups (A: 3.73±0.67, B: 3.70±0.44, C: 3.68±0.56, and D: 3.76±0.50; P = 0.659), but the scores of subjective image quality for group E (3.02±0.69) were lower than those of other groups (P < 0.001) as shown in Table 4 and Fig. 1. In particular, even though the mean subjective image quality score of group E was 3.02, meting the diagnostic requirements the subjective image quality scores of five patients’ images were below 3 (Table 4), while the subjective scores of all patient images in the other four groups were above 3. Part II: The scores of subjective image qualities in the D0–D5 subgroups were 3.50±0.71, 3.70±0.68, 3.80±0.75, 3.83±0.69, 4.09±0.83, and 3.72±0.51, respectively. There were significant differences in subgroup D4, whose subjective score was higher than other subgroups (P < 0.001) as shown in Table 3 and Fig. 3.

Table 4
The Subjective image quality evaluation among the five groups

A B C D E

Subjective image quality score max 4.1 4.3 4.5 5.0 4.0

ave 3.37 3.70 3.68 3.76 3.02

mini 3.0 3.2 3.3 3.5 2.7

Number of persons by section 2-3 0 0 0 0 5

3-4 23 20 16 11 24

4-5 7 10 14 19 1

		A	B	C	D	E
Subjective image quality score	max	4.1	4.3	4.5	5.0	4.0
	ave	3.37	3.70	3.68	3.76	3.02
	mini	3.0	3.2	3.3	3.5	2.7
Number of persons by section	2-3	0	0	0	0	5
	3-4	23	20	16	11	24
	4-5	7	10	14	19	1

3.4 Radiation dose estimations

The ED of the A–E groups were 15.26±0.42, 14.19±0.49, 13.22±0.48, 12.38±0.60, and 11.25±0.46, respectively. The percentages of pre-ASiR-V and ED values had a negative correlation, The correlation coefficients r=–0.938(P = 0.000). Statistical analyses showed that the EDs showed significant differences among the five groups (P < 0.001). Compared with group A, the ED values in groups B, C, and D decreased by 7.01%, 13.37%, and 18.87%, respectively (Table 1 and Fig. 2).

4 Discussion

In recent years, multi-slice spiral CT has been rapidly developed for clinical use, and CCTA as a noninvasive and reliable technique has been widely used in the clinic. At the same time, the radiation dose used in the CT examination is associated with the risk of cancer and high ionizing radiation in CT examination is also a problem that cannot be ignored [19, 20]. Therefore, it is important to reduce the patient’s radiation dose while retaining the image quality and diagnostic accuracy.

ASiR-V is the third generation of iterative reconstruction that can obtain better image quality at the same scanning conditions, when compared with the first generation of ASiR [21 –24], and can reconstruct images more effectively compared with the Model Based Iterative Reconstruction [25, 26]. It is the reconstruction technique that enables reduction in image noise, streak artifacts at low signal conditions, and improvement in low contrast detectability, while preserving the structural details in the image. It can be used to reduce the image noise and streak in diagnostic images to reduce the dose required for routine imaging. ASiR-V can also automatically adjust the scanning mA according to different tissue densities of the body, to further reduce the radiation dose [27, 28]. ASiR-V has two modes: pre-ASiR-V and post-ASiR-V. Both of these modes have different options; pre-ASiR-V can adjust the tube current according to automatic tube current modulation technology while the CT value is not affected. Post-ASiR-V can significantly reduce the image noise and streak artifacts to improve image detail and quality. Previous studies have reported that post-ASiR-V with a higher percentage results in an improved image over smooth images, which affect the detection of small lesions [29 –31]. Choosing an appropriate percentage of post-ASiR-V is therefore a key to maximizing image quality.

Part I of our study showed that the image noise values of all images had a positive correlation with the pre-ASiR-V level, and the SNR and CNR of all images had a negative correlation with the pre-ASiR-V level. The radiation dose of CCTA was reduced with an increase of the pre-ASiR-V levels. There were no significant statistical differences in scores of subjective image quality, SNR, and CNR when the percentage ranges of the pre-ASiR-V level were 40%–70%. The image noise significantly increased while scores of subjective image quality, SNR, and CNR were reduced relative to when the percentage range of the pre-ASiR-V level was > 70%. To avoid failure of the CCTA examination, the maximum percentage of pre-ASiR-V levels used was 80% in our study. Our study also showed that the wide-detector combined with a 70% pre-ASiR-V level resulted in a lower radiation dose than the value of the manufacturer’s recommended value (40%), which decreased by 18.87% while retaining image quality.

Part II of our study showed that the image noise value of all images had a negative correlation with the percentage of the post-ASiR-V value, and the SNR and CNR of all images had a positive correlation with the percentage of post-ASiR-V values. The image noise decreased and the SNR and CNR values increased as the percentage of post-ASiR-V level increased. The mean CT attention did not change significantly as the percentage of post-ASiR-V levels increased. The CNR of the reconstructed image was 19.41±4.90 when the percentage of post-ASiR-V was 80%. The subjective score of the D0 D4 subgroup reconstructed image increased gradually and the D5 subgroup images decreased. It was possible that a high percentage of ASiR-V (90%) changed the noise component, resulting in an improved image over the smooth method, which affected the diagnosis. In this section, the subjective score of the reconstructed image was the highest with 80% post-ASiR-V [32].

Our study had some limitations. First, the patient population was relatively small and a certain amount of samples were needed to ensure that the results were accurate. Second, the effects of different heart rates and rhythms on image quality were not considered. Third, we did not assess the effect of different BMIs in this study. In future studies, patients should therefore be grouped according to their BMI to reduce the effects of image quality.

In conclusion, increasing the percentage of pre-ASiR-V significantly reduced the radiation dose. Increasing the percentage of post-ASiR-V also significantly reduced the image noise and improved the image quality. Overall, our study showed that 70% pre-ASiR-V and 80% post-ASiR-V was the best reconstruction algorithm in CCTA examinations of adults.

Footnotes

Acknowledgments

Funding: This study was funded by Key R & D projects of Hebei Province (Grant number: 20377765D), Hebei province program of training and basic project of clinical medicine of China (Grant number: 361007), Postgraduate Innovation Project of Hebei University (Grant number: hbu2019ss037), and the affiliated hospital of Hebei university outstanding youth foundation (Grant numbers: 2015Q002 and 2015Q017).

Conflict of interest: All autors declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted.

Ethical approval: All procedures performed in our study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

References

Richards

C.E.

and Obaid

D.R.

, Low-dose radiation advances in coronary computed tomography angiography in the diagnosis of coronary artery disease, Curr Cardiol Rev 15(4) (2019), 304–315.

Rudziński

P.N.

, Kruk

, Kępka

, et al., The value of coronary artery computed tomography as the first-line anatomical test for stable patients with indications for invasive angiography due to suspected Coronary Artery Disease: CAT-CAD randomized trial, J Cardiovasc Comput Tomogr 12(6) (2018), 472–479.

Liu

, Fu

, Yu

, et al., Evaluate of the effect of low tube voltage on the radiation dosage using 640-slice coronary CT angiography, J Xray Sci Technol 26(3) (2018), 463–471.

Lin

Z.X.

, Zhou

C.S.

, Schoepf

U.J.

, et al., Coronary CT angiography radiation dose trends: A 10-year analysis to develop institutional diagnostic reference levels, Eur J Radiol 113 (2019), 140–147.

Ohno

, Koyama

, Seki

, et al., Radiation dose reduction techniques for chest CT: Principles and clinical results, Eur J Radiol 111 (2019), 93–103.

Zhao

, Geng

, Zhang

, et al., Assessment of radiation dose and iodine load reduction in head-neck CT angiography using two scan protocols with wide-detector, J Xray Sci Technol 27(5) (2019), 981–993.

Mousavi Gazafroudi

S.S.

, Tavakkoli

M.B.

, Moradi

, et al., Coronary CT angiography by modifying tube voltage and contrast medium concentration: Evaluation of image quality and radiation dose, Echocardiography 36(7) (2019), 1391–1396.

Lee

, Kim

T.H.

, Lee

B.K.

, et al., Diagnostic accuracy of low-radiation coronary computed tomography angiography with low tube voltage and knowledge-based model reconstruction, Sci Rep 9(1) (2019), 1308–1317.

Lee

H.S.

, Suh

Y.J.

, Han

, et al., Effectiveness of automatic tube potential selection with tube current modulation in coronary CT angiography for obese patients: Comparison with a body mass index-based protocol using the propensity score matching method, PLoS One 13(1) (2018), e0190584.

10.

Papadakis

A.E.

and Damilakis

, Automatic tube current modulation and tube voltage selection in pediatric computed tomography: A phantom study on radiation dose and image quality, Invest Radiol 54(5) (2019), 265–272.

11.

Yel

, Booz

, Albrecht

M.H.

, et al., Optimization of image quality and radiation dose using different cone-beam CT exposure parameters, European Journal of Radiology 116 (2019), 68–75.

12.

De Marco

and Origgi

, New adaptive statistical iterative reconstruction ASiR-V: Assessment of noise performance in comparison to ASiR, J Appl Clin Med Phys 19(2) (2018), 275–286.

13.

Laurent

, Villani

, Hossu

, et al., Full model-based iterative reconstruction (MBIR) in abdominal CT increases objective image quality, but decreases subjective acceptance, Eur Radiol 29(8) (2019), 4016–4025.

14.

Rotzinger

D.C.

, Racine

, Beigelman-Aubry

, et al., Task-based model observer assessment of a partial model-based iterative reconstruction algorithm in thoracic oncologic multidetector CT, Sci Rep 8(1) (2018), 17734.

15.

, Yang

, Wen

, et al., Ultra-low-dose multiphase CT angiography derived from CT perfusion data in patients with middle cerebral artery stenosis, Neuroradiology 62(2) (2020), 167–174.

16.

Kang

E.J.

, Lee

K.N.

, et al., An initial randomised study assessing free-breathing CCTA using 320-detector CT, Eur Radiol 23(5) (2013), 1199–1209.

17.

Barrington

S.F.

and Kluge

, FDG PET for therapy monitoring in Hodgkin and non-Hodgkin lymphomas, Eur J Nucl Med Mol Imaging 44(Suppl 1) (2017), 97–110.

18.

Trattner

, Halliburton

, Thompson

C.M.

, et al., Cardiac-specific conversion factors to estimate radiation effective dose from dose-length product in computed tomography, JACC Cardiovascular Imaging 11(1) (2018), 64–74.

19.

Elmokadem

A.H.

, Ibrahim

E.A.

, Gouda

W.A.

, et al., Whole-body computed tomography using low-dose biphasic injection protocol with adaptive statistical iterative reconstruction V: assessment of dose reduction and image quality in trauma patients, J Comput Assist Tomogr 43(6) (2019), 870–876.

20.

Park

, Choo

K.S.

, Kim

J.H.

, et al., image quality and radiation dose in CT venography using model-based iterative reconstruction at 80 kVp versus adaptive statistical iterative reconstruction-V at 70 kVp, Korean J Radiol 20(7) (2019), 1167–1175.

21.

Akai

, Kiryu

, Shibata

, et al., Reducing CT radiation exposure with organ effective modulation: A retrospective clinical study, European Journal of Radiology 85(9) (2016), 1569–1573.

22.

Fang

, Deng

, Law

MW-M

, et al., Comparison of image quality and radiation exposure between conventional imaging and gemstone spectral imaging in abdominal CT examination, Br J Radiol 91(1088) (2018), 20170448.

23.

Choi

Y.J.

, Lee

J.H.

, Yoon

D.H.

, et al., Effect of an arm traction device on image quality and radiation exposure during neck CT: A prospective study, AJNR Am J Neuroradiol 39(1) (2018), 151–155.

24.

Weinman

J.P.

, Mirsky

D.M.

, Jensen

A.M.

, et al., Dual energy head CT to maintain image quality while reducing dose in pediatric patients, Clin Imaging 55 (2019), 83–88.

25.

Matenine

, Schmittbuhl

, Bedwani

, et al., Iterative reconstruction for image enhancement and dose reduction in diagnostic cone beam CT imaging, J Xray Sci Technol 27(5) (2019), 805–891.

26.

Ohira

, Kanayama

, Wada

, et al., A Third-generation adaptive statistical iterative reconstruction for contrast-enhanced 4-dimensional dual-energy computed tomography for pancreatic cancer, J Comput Assist Tomogr 2019; doi: 10.1097/RCT.0000000000000942.

27.

Pontone

, Muscogiuri

, Andreini

, et al., Impact of a new adaptive statistical iterative reconstruction (ASIR)-V algorithm on image quality in coronary computed tomography angiography, Acad Radiol 25(10) (2018), 1305–1313.

28.

Wang

X.P.

, Hou

, Lü

P.J.

, et al., Application of adaptive statistical iterative reconstruction V (ASIR-V) in contrast-enhanced abdominal scanning with low-dose for liver cirrhosis, Zhonghua Yi Xue Za Zhi 99(27) (2019), 2124–2129.

29.

Wang

H.X.

, Lü

P.J.

, Yue

S.W.

, et al., Combined use of wide-detector and adaptive statistical iterative reconstruction-V technique in abdominal CT with low radiation dose, Zhonghua Yi Xue Za Zhi 97(45) (2017), 3567–3572.

30.

Chen

L-H.

, Jin

, Li

J-Y.

, et al., Image quality comparison of two adaptive statistical iterative reconstruction (ASiR, ASiR-V) algorithms and filtered back projection in routine liver CT, Br J Radiol 91(1088) (2018), 20170655.

31.

Goodenberger

M.H.

, Wagner-Bartak

N.A.

, Gupta

, et al., Computed tomography image quality evaluation of a new iterative reconstruction algorithm in the abdomen (adaptive statistical iterative reconstruction-V) a comparison with model-based iterative reconstruction, adaptive statistical iterative reconstruction, and filtered back projection reconstructions, J Comput Assist Tomogr 42(2) (2018), 184–190.

32.

Tang

, Yu

, Jia

, et al., Assessment of noise reduction potential and image quality improvement of a new generation adaptive statistical iterative reconstruction (ASIR-V) in chest CT, Br J Radiol 91(1081) (2018), 20170521.

Comparison of image quality and radiation dose using different pre-ASiR-V and post-ASiR-V levels in coronary computed tomography angiography

Abstract

OBJECTIVE:

METHODS:

RESULTS:

CONCLUSION:

Keywords

1 Introduction

2 Methods and materials

2.1 Patient population

2.3 Objective image quality evaluation

2.4 Subjective image quality evaluation

2.6 Statistical analyses

3 Results

3.1 The general situation

3.2 Quantitative image analysis

Table 4 The Subjective image quality evaluation among the five groups A B C D E Subjective image quality score max 4.1 4.3 4.5 5.0 4.0 ave 3.37 3.70 3.68 3.76 3.02 mini 3.0 3.2 3.3 3.5 2.7 Number of persons by section 2-3 0 0 0 0 5 3-4 23 20 16 11 24 4-5 7 10 14 19 1

4 Discussion

Footnotes

Acknowledgments

References

Table 4
The Subjective image quality evaluation among the five groups

A B C D E

Subjective image quality score max 4.1 4.3 4.5 5.0 4.0

ave 3.37 3.70 3.68 3.76 3.02

mini 3.0 3.2 3.3 3.5 2.7

Number of persons by section 2-3 0 0 0 0 5

3-4 23 20 16 11 24

4-5 7 10 14 19 1