Attenuation-based automatic kilovolt (kV)-selection in computed tomography of the chest: effects on radiation exposure and image quality

Radiation dose reduction and image quality enhancement for patients unable to elevate their arms in chest CT: A comparative study

PURPOSE

To propose a method to effectively reduce radiation dose while enhancing image quality in chest CT for patients unable to elevate their arms utilizing the air-gap technique.

METHODS

Chest CT images were acquired in three positions: arms raised (control group, position A), arms lowered with the air-gap technique utilizing an in-house device (position B), and arms lowered without the device (position C). Data were categorized by body weight. Radiation dose was assessed using dose-length product (DLP) values, with quantitative analyses of image noise, contrast-to-noise ratio (CNR), and CNR-to-dose ratio (CNRDR). Qualitative assessment utilized a Likert scale.

RESULTS

Average DLP was 473.7 ± 142.9 mGy × cm in position C, with the lowest in position A at 267.3 ± 93.3 mGy × cm. Position B had a DLP of 317.2 ± 121.4 mGy × cm, 18.7 % higher than position A but 33.0 % lower than position C. In patients over 70 kg, all positions exceeded the thoracic CT diagnostic reference level (DRL) (324.2 mGy × cm). For those under 70 kg (i.e., <50 kg, 50-70 kg), position B showed lower DLPs compared to the above DRL. Quantitative analysis indicated that position B maintained image quality similar to position A, with CNRDR of 30.2 ± 11.1 versus 26.6 ± 10.9 in position A, showing marginal significance (p = 0.046). The qualitative evaluation indicated that position A had the highest rating at 4.96, followed by position B at 4.51, and position C at 3.47.

CONCLUSION

The air-gap device with lowered arms during chest CT for patients unable to elevate their arms can reduce radiation dose while maintaining image quality. A custom-designed device facilitates safe and efficient procedures, especially for patients with higher body weight.

Determining optimal imaging protocols for enhanced chest CT: From phantom to clinical study

OBJECTIVES

To investigate the optimal imaging protocols for enhanced chest CT to achieve good image quality and diagnostic performance with a lower radiation dose.

MATERIALS AND METHODS

This IRB-approved study included both phantoms and patients. Two phantoms were scanned using 4 scanning modes. Images in each group were reconstructed using adaptive statistical iterative reconstruction-V (ASiR-V) at three strength levels of 40%, 60%, and 80%, denoted A1-3-D1-3, respectively with 1-3 representing the three ASiR-V levels. The image quality and radiation dose were evaluated to obtain the best imaging mode. 48 patients underwent contrast-enhanced standard dose CT (SDCT, protocol A) and low-dose CT (LDCT, protocol D) of the chest for follow-up. The image quality, radiation dose, and volume measurements of the left lung, right lung, and trachea using an AI-based software were compared.

RESULTS

In the phantom study, D2 protocol which had the lowest dose, was selected as the optimal imaging protocol for enhanced chest CT. Compared with SDCT, LDCT reduced the radiation dose by 45% compared to SDCT. Images in LDCT with ASiR-V60% had similar noise as the standard SDCT images with the standard ASiR-V40%, but they had higher SNRs and CNRs. In addition, the volumes of the left lung, right lung, and bronchus did not significantly differ between the two groups.

CONCLUSION

The combination of Auto-kV prescription and ODMfull with ASiR-V60% in contrast-enhanced chest CT can achieve individualized low dose scanning with satisfactory image quality and diagnostic accuracy.

Comparison of selected photon shield and organ-based tube current modulation for radiation dose reduction in head computed tomography: A phantom study

OBJECTIVE

The aim of this study is to investigate the radiation dose and image quality of head CT using SPS and OBTCM techniques.

METHODS

Three anthropomorphic head phantoms (1-yr-old, 5-yr-old, and adult) were used. Images were acquired using four modes (Default protocol, OBTCM, SPS, and SPS+OBTCM). Absorbed dose to the lens, anterior brain (brain_A), and posterior brain (brain_P) was measured and compared. Image noise and CNR were assessed in the selected regions of interest (ROIs).

RESULTS

Compared with that in the Default protocol, the absorbed dose to the lens reduced by up to 28.33%,71.38%, and 71.12% in OBTCM, SPS, and SPS+OBTCM, respectively. The noise level in OBTCM slightly (≤1.45HU) increased than that in Default protocol, and the SPS or SPS+OBTCM mode resulted in a quantitatively small increase (≤2.58HU) in three phantoms. There was no significant difference in CNR of different phantoms under varies scanning modes (p >  0.05).

CONCLUSIONS

During head CT examinations, the SPS mode can reduce the radiation dose while maintaining image quality. SPS+OBTCM couldn't further effectively reduce the absorbed dose to the lens for 1-yr and 5-yr-old phantoms. Thus, SPS mode in pediatric and SPS+OBTCM mode in adult are better than other modes, and should be used in clinical practice.

FIRST CARDIAC COMPUTED TOMOGRAPHY TYPICAL RADIATION DOSE VALUES FROM A SINGLE CENTRE IN NIGERIA: A PILOT STUDY

Concern regarding radiation dose associated with cardiac computed tomography (CT) still exists and requires the use of diagnostic reference levels for dose optimisation. Typical median doses were established for 58 consented adult patients from a single centre for coronary artery calcium score (CACS) as volume computed tomography dose index (CTDIvol): 5.9 mGy; dose length product (DLP): 86.6 mGy*cm and cardiac CT angiography (CCTA) as CTDIvol: 11.1 mGy; DLP: 190.8 mGy*cm. Wide radiation dose variability in terms of CTDIvol was noted for CACS: 2.7-15.9 mGy, a 6-fold, whereas for CCTA it ranges from 3.8 to 52.8 mGy, a 14-fold. The DLP values for CACS range from 33.2 to 344.2 mGy*cm, which is 10-fold, whereas for CCTA it ranges from 32.8 to 834.9 mGy*cm, a 25-fold. The typical values compared lower than the radiation dose from other countries; however, the wide variability in dose remains a call for concern.

[A Review of Current Knowledge for X-ray Energy in CT: Practical Guide for CT Technologist]

In computed tomography (CT) systems, the optimal X-ray energy in imaging depends on the material composition and the subject size. Among the parameters related to the X-ray energy, we can arbitrarily change only the tube voltage. For years, the tube voltage has often been set at 120 kVp. However, since about 2000, there has been an increasing interest in reducing radiation dose, and it has led to the publication of various reports on low tube voltage. Furthermore, with the spread of dual-energy CT, virtual monochromatic X-ray images are widely used since the contrast can be adjusted by selecting the optional energy. Therefore, because of the renewed interest in X-ray energy in CT imaging, the issue of energy and imaging needs to be summarized. In this article, we describe the basics of physical characteristics of X-ray attenuation with materials and its influence on the process of CT imaging. Moreover, the relationship between X-ray energy and CT imaging is discussed for clinical applications.

Technical note: Evaluation of Artificial 120-kilovolt computed tomography images for radiation therapy applications

PURPOSE

The purpose of this work is to evaluate the scaled CT number accuracy of an artificial 120 kV reconstruction technique based on phantom experiments in the context of radiation therapy planning.

METHODS

An abdomen-shaped electron density phantom was scanned on a clinical CT scanner capable of artificial 120 kV reconstruction using different tube potentials from 70 kV to 150 kV. A series of tissue equivalent phantom inserts (lung, adipose, breast, solid water, liver, inner bone, 30%/50% CaCO3, cortical bone) were placed inside the phantom. Images were reconstructed using a conventional quantitative reconstruction kernel as well as the artificial 120 kV reconstruction kernel. Scaled CT numbers of inserts were measured from images acquired at different kVs and compared with those acquired at 120 kV, which were deemed as the ground truth. The relative error was quantified as the percentage deviation of scaled CT numbers acquired at different tube potentials from their ground truth values acquired at 120 kV.

RESULTS

Scaled CT numbers measured from images reconstructed using the conventional reconstruction demonstrated a strong kV-dependence. The relative error in scaled CT number ranged from 0.6% (liver insert) to 31.1% (cortical bone insert). The artificial 120 kV reconstruction reduced the kV-dependence, especially for bone tissues. The relative error in scaled CT number was reduced to 0.4% (liver insert) and 2.6% (30% CaCO₃ insert) using this technique. When tube potential selection was limited to the range of 90 kV to 150 kV, the relative error was further restrained to <1.2% for all tissue types.

CONCLUSION

Phantom results demonstrated that using the artificial 120 kV technique, it was feasible to acquire raw projection data at a desired tube potential and then reconstruct images with scaled CT numbers comparable to those obtained directly at 120 kV. In radiotherapy applications, this technique may allow optimization of tube potential without complicating clinical workflow by eliminating the necessity of maintaining multiple sets of CT calibration curves. This article is protected by copyright. All rights reserved.

Comparison of the image quality and radiation dose of different scanning modes in head-neck CT angiography

OBJECTIVES

To analyze and compare the radiation dose and image quality of different CT scanning modes on head-neck CT angiography.

METHODS

A total of 180 patients were divided into Group A and Group B. The groups were further subdivided according to different scanning modes: subgroups A1, A2, A3, B1, B2, and B3. Subgroups A1 and B1 used conventional CT protocol, subgroups A2 and B2 used the kV-Assist scan mode, and subgroups A3 and B3 used the dual-energy gemstone spectral imaging protocol. The CT dose index and dose-length product were recorded. The objective image quality and subjective image evaluation was conducted by two independent radiologists.

RESULTS

The signal-to-noise ratios, contrast-to-noise ratios, and subjective scores of subgroups A3 and B3 were higher than the other subgroups. In subgroups B1 and B2, the subjective scores of 9 patients and 12 patients were lower than 3, respectively. The subjective scores of subgroups B1 and B2 were lower than the other subgroups. There was no statistically significant difference in signal-to-noise ratios, contrast-to-noise ratios, and subjective scores between subgroups A1 and A2. The effective dose of subgroup A2 was 41.7 and 36.4% lower than that in subgroups A1 and A3, respectively (p < 0.05). In Group B, there were no statistically significant differences in CT dose indexvol, dose-length product, and ED among the subgroups (p > 0.05).

CONCLUSION

In the head-neck CT angiography, the kV-Assist scan mode is recommended for patients with body mass index between 18.5 and 34.9 kg m^-2; gemstone spectral imaging scanning mode is recommended for patients with body mass index ≥34.9 kg m^-2.

Carotid CTA at the Lowest Tube Voltage (70 kV) in Comparison with Automated Tube Voltage Adaption

BACKGROUND AND PURPOSE

CTA is the imaging modality of choice in many institutions for the evaluation of the supraaortic vessels, but radiation exposure remains a matter of concern. Our aim was to evaluate a 70-kV protocol for CT angiography of the carotid arteries with respect to image quality and radiation exposure compared with automated tube voltage adaption.

MATERIALS AND METHODS

A total of 90 consecutive patients were included in this prospective study and randomized to the study group (n = 45, 70 kV) or control group (n = 45, automated tube voltage adaptation). Volume CT dose indices and dose-length products were recorded in the examination protocol. Image quality was assessed as arterial vessel contrast, signal-to-noise ratio, contrast-to-noise ratio, and contrast-to-noise ratio in reference to the radiation dose. Subjective overall image-quality analysis, image-artifact analysis, and diagnostic evaluation were performed by 2 observers by using a 4-point Likert scale.

RESULTS

Radiation exposure was significantly lower in the study group (volume CT dose index reduced by 22%, dose-length product reduction by 20%; each P < .001). Contrast (P = .15), SNR (P = .4), and contrast-to-noise ratio (P = .5) did not show significant differences between the groups. The contrast-to-noise ratio in reference to the radiation dose was not significantly increased using the study protocol (P = .2). Subjective image quality and visualization of pathologic findings did not differ significantly between the groups.

CONCLUSIONS

Carotid CTA using the lowest available voltage (70 kV) is feasible at very-low-dose levels, while overall image quality is comparable with protocols using automated tube voltage selection.

Extent of simultaneous radiation dose and iodine reduction at stable image quality in computed tomography of the chest: A systematic approach using automated tube voltage adaption and iterative reconstructions

BACKGROUND

Aim of this study was to systematically combine tube voltage adaptation and iterative reconstructions for reduction of iodine and radiation dose.

METHODS

Settings for the study protocol were evaluated in ex-ante trials to provide image quality that is comparable to a reference protocol at 120 kV with tube current modulation. Consecutive patients were randomized to undergo computed tomography (CT) of the chest using the study protocol (n = 62) or reference protocol (n = 50). Objective and subjective image quality was assessed and compared.

RESULTS

Tube voltage was decreased to 100 kV in 47 patients and to 80 kV in 15 patients in the study group. The iodine dosage (16.1 vs 10.5 g) and the effective radiation dose (3.6 vs 2.5 mSv) were significantly decreased in the study group (both P < .001). Contrast-to-noise ratio was comparable in the pulmonary trunk and increased in the aorta (P < .01). Subjective image quality was comparable without statistically significance.

CONCLUSIONS

Simultaneous reductions in iodine dosage and radiation dose by one-third are feasible for CT of the chest.

Attenuation-based kV pair selection in dual source dual energy computed tomography angiography of the chest: impact on radiation dose and image quality

OBJECTIVES

The purpose of this study was to evaluate the impact of attenuation-based kilovoltage (kV) pair selection in dual source dual energy (DSDE)-pulmonary embolism (PE) protocol examinations on radiation dose savings and image quality.

METHODS

A prospective study was carried out on 118 patients with suspected PE. In patients in whom attenuation-based kV pair selection selected the 80/140Sn kV pair, the pre-scan 100/140Sn CTDIvol (computed tomography dose index volume) values were compared with the pre-scan 80/140Sn CTDIvol values. Subjective and objective image quality parameters were assessed.

RESULTS

Attenuation-based kV pair selection switched to the 80/140Sn kV pair ("switched" cohort) in 63 out of 118 patients (53%). The mean 100/140Sn pre-scan CTDIvol was 8.8 mGy, while the mean 80/140Sn pre-scan CTDIvol was 7.5 mGy. The average estimated dose reduction for the "switched" cohort was 1.3 mGy (95% CI 1.2, 1.4; p < 0.001), representing a 15% reduction in dose. After adjusting for patient weight, mean attenuation was significantly higher in the "switched" vs. "non-switched" cohorts in all five pulmonary arteries and in all lobes on iodine maps.

CONCLUSIONS

This study demonstrates that attenuation-based kV pair selection in DSDE examination is feasible and can offer radiation dose reduction without compromising image quality.

KEY POINTS

• Attenuation-based kV pair selection in dual energy examination is feasible. • It can offer radiation dose reduction to approximately 50% of patients. • Approximate 15% reduction in radiation dose was achieved using this technique. • The image quality is not compromised by use of attenuation-based kV pair selection.

Scout-Based Automated Tube Potential Selection Technique (kV Assist) in Enhanced Chest Computed Tomography: Effects on Radiation Exposure and Image Quality

OBJECTIVE

The aim of our study was to assess radiation dose reduction and image quality for enhanced chest CT examinations with a scout-based automated tube potential selection technique (kV Assist) compared with a standard 120-kV protocol.

METHODS

Prospective study of enhanced chest CT examinations was performed in 100 consecutive patients with kV Assist and in 100 consecutive patients with conventional 120-kV protocol on a multislice CT (Discovery CT750 HD). The body mass index, CT dose index volume, and dose length product were recorded from the examination protocol. Image noise and CT value was measured on region of interest, signal-to-noise ratio, and contrast-to-noise ratio was calculated. The subjective image quality was assessed by two radiologists blinded to the respective protocol with the use of a 3-grade scale (3, superior quality; 2, moderate quality; 1, inferior quality).

RESULTS

With kV Assist, the percentages of patients being scanned using 80, 100, and 120 kV were 12.0%, 80.0%, and 8.0%, respectively. The kilovolt setting was related with body mass index (r = 0.565, P = 0.000). Compared with the conventional 120 kV protocol, kV Assist allowed for an overall average decrease of 30.6% in CT dose index volume (kV Assist, 11.05 ± 4.78 mGy; 120 kV, 15.92 ± 6.89 mGy) (P < 0.001) and 32.3% in dose length product (kV Assist, 386.41 ± 184.02 mGy cm; 120 kV, 571.14 ± 286.68 mGy cm) (P < 0.001). In the kV Assist, mean attenuation of regions of interest inside the aorta was significantly higher than that in 120-kV protocols (kV Assist, 310.27 ± 73.70 HU; 120 kV, 239.44 ± 47.65 HU) (P < 0.001), resulting in increased contrast-to-noise ratio (kV Assist, 26.69 ± 7.78; 120 kV, 21.38 ± 6.05) (P < 0.001). There was no significant difference in subjective image quality scores between the 2 groups.

CONCLUSIONS

The use of attenuation-based kV Assist technique enables significant dose reduction in enhanced chest CT scan while improving arterial enhancement and preserving image quality at adequate levels.

Automated tube voltage adaptation in combination with advanced modeled iterative reconstruction in thoracoabdominal third-generation 192-slice dual-source computed tomography: effects on image quality and radiation dose

RATIONALE AND OBJECTIVES

To evaluate image quality and radiation exposure of portal venous-phase thoracoabdominal third-generation 192-slice dual-source computed tomography (DSCT) with automated tube voltage adaptation (TVA) in combination with advanced modeled iterative reconstruction (ADMIRE).

MATERIALS AND METHODS

Fifty-one patients underwent oncologic portal venous-phase thoracoabdominal follow-up CT twice within 7 months. The initial examination was performed on second-generation 128-slice DSCT with fixed tube voltage of 120 kV in combination with filtered back projection reconstruction. The second examination was performed on a third-generation 192-slice DSCT using automated TVA in combination with ADMIRE. Attenuation and image noise of liver, spleen, renal cortex, aorta, vena cava inferior, portal vein, psoas muscle, and perinephric fat were measured. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Radiation dose was assessed as size-specific dose estimates (SSDE). Subjective image quality was assessed by two observers using five-point Likert scales. Interobserver agreement was calculated using intraclass correlation coefficients (ICC).

RESULTS

Automated TVA set tube voltage to 90 kV (n = 8), 100 kV (n = 31), 110 kV (n = 11), or 120 kV (n = 1). Average SSDE was decreased by 34.9% using 192-slice DSCT compared to 128-slice 120-kV DSCT (7.8 ± 2.4 vs. 12.1 ± 3.2 mGy; P < .001). Image noise was substantially lower; SNR and CNR were significantly increased in 192-slice DSCT compared to 128-slice DSCT (all P < .005). Image quality was voted excellent for both acquisition techniques (5.00 vs. 4.93; P = .083).

CONCLUSIONS

Automated TVA in combination with ADMIRE on third-generation 192-slice DSCT in portal venous-phase thoracoabdominal CT provides excellent image quality with reduced image noise and increased SNR and CNR, whereas average radiation dose is reduced by 34.9% compared to 128-slice DSCT.

Pediatric Computed Tomography Dose Optimization Strategies: A Literature Review

INTRODUCTION

Computed tomography (CT) dose optimization is an important issue in radiography because CT is the largest contributor to medical radiation dose and its use is increasing. However, CT dose optimization for pediatric patients could be more challenging than their adult counterparts. The purpose of this literature review was to identify and discuss the current pediatric CT dose saving techniques. Optimized pediatric protocols were also proposed.

METHODS

A comprehensive literature search was conducted using the Medline, ProQuest Health and Medical Complete, PubMed, ScienceDirect, Scopus, Springer Link, and Web of Science databases and the keywords CT, pediatric, optimization, protocol, and radiation dose to identify articles focusing on pediatric CT dose optimization strategies published between 2004 and 2014.

RESULTS AND SUMMARY

Seventy-seven articles were identified in the literature search. Strategies for optimizing a range of scan parameters and technical considerations including tube voltage and current, iterative reconstruction, diagnostic reference levels, bowtie filters, scout view, pitch, scan collimation and time, overscanning, and overbeaming for pediatric patients with different ages and body sizes and compositions were discussed. An example of optimized pediatric protocols specific to age and body size for the 64-slice CT scanners was devised. It is expected that this example could provide medical radiation technologists, radiologists, and medical physicists with ideas to optimize their pediatric protocols.

Imaging the Parasinus Region with a Third-Generation Dual-Source CT and the Effect of Tin Filtration on Image Quality and Radiation Dose

BACKGROUND AND PURPOSE

CT is the imaging technique of choice in the evaluation of midface trauma or inflammatory disease. We performed a systematic evaluation of scan protocols to optimize image quality and radiation exposure on third-generation dual-source CT.

MATERIALS AND METHODS

CT protocols with different tube voltage (70-150 kV), current (25-300 reference mAs), prefiltration, pitch value, and rotation time were systematically evaluated. All images were reconstructed with iterative reconstruction (Advanced Modeled Iterative Reconstruction, level 2). To individually compare results with otherwise identical factors, we obtained all scans on a frozen human head. Conebeam CT was performed for image quality and dose comparison with multidetector row CT. Delineation of important anatomic structures and incidental pathologic conditions in the cadaver head was evaluated.

RESULTS

One hundred kilovolts with tin prefiltration demonstrated the best compromise between dose and image quality. The most dose-effective combination for trauma imaging was Sn100 kV/250 mAs (volume CT dose index, 2.02 mGy), and for preoperative sinus surgery planning, Sn100 kV/150 mAs (volume CT dose index, 1.22 mGy). "Sn" indicates an additional prefiltration of the x-ray beam with a tin filter to constrict the energy spectrum. Exclusion of sinonasal disease was possible with even a lower dose by using Sn100 kV/25 mAs (volume CT dose index, 0.2 mGy).

CONCLUSIONS

High image quality at very low dose levels can be achieved by using a Sn100-kV protocol with iterative reconstruction. The effective dose is comparable with that of conventional radiography, and the high image quality at even lower radiation exposure favors multidetector row CT over conebeam CT.

Adaptation of contrast injection protocol to tube potential for cardiovascular CT

OBJECTIVE

The purpose of this study was to investigate and validate adaptation of a cardiovascular CT angiography contrast injection protocol for lower tube potential.

MATERIALS AND METHODS

Eighty-three patients evaluated for thoracic aortic disease with a 256-MDCT scanner were imaged at 120 kV (group 1) or 100 kV (group 2) with the same contrast protocol (90 mL iopromide 370 mg I/mL at 3.5 mL/s). A pharmacokinetic model was validated and used to simulate aortic attenuation in group 2 patients with 20%, 33%, and 44% reduction in contrast volume. A 44% volume reduction was applied to 50 additional patients who underwent imaging at 100 kV (group 3). Patient characteristics, scanning and radiation parameters, and objective and subjective image indexes were compared among groups.

RESULTS

Group 2 patients had higher mean aortic blood attenuation (399±61 HU) than group 1 patients (281±48 HU) (p<0.001) but similar image noise. Group 3 and group 1 patients had similar mean aortic attenuation and noise. Subjective assessment of image quality indicated that group 3 and group 1 had comparable percentages of images with good or excellent diagnostic confidence scores (reader 1, 98% vs 96%; reader 2, 96% vs 96%).

CONCLUSION

Lower tube potential (100 kV) for cardiothoracic CT could be accompanied by a 44% reduction in contrast volume with satisfactory aortic blood-pool attenuation in most patients. More personalized adaptation of the contrast protocol that takes into account patient characteristics and tube potential is necessary to ensure sufficient contrast enhancement for all patients.

Reduced radiation dose and improved image quality at cardiovascular CT angiography by automated attenuation-based tube voltage selection: intra-individual comparison

OBJECTIVES

To evaluate the effect of automated tube voltage selection on radiation dose and image quality at cardiovascular CT angiography (CTA).

METHODS

We retrospectively analysed paired studies in 72 patients (41 male, 60.5 ± 16.5 years), who had undergone CTA acquisitions of the heart or aorta both before and after the implementation of an automated x-ray tube voltage selection algorithm (ATVS). All other parameters were kept identical between the two acquisitions. Subjective image quality (IQ) was rated and objective IQ was measured by image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and figure of merit (FOM). Image quality parameters and effective dose were compared between acquisitions.

RESULTS

Overall subjective image quality improved with the percentage of cases scored as adequate or higher increasing from 79 % to 92 % after implementation of ATVS (P = 0.03). SNR (14.1 ± 5.9, 15.7 ± 6.1, P = 0.009), CNR (11.6 ± 5.3, 13.2 ± 5.6, P = 0.011), and FOM (19.9 ± 23.3, 43.8 ± 51.1, P < 0.001) were significantly higher after implementation of ATVS. Mean image noise (24.1 ± 8.4 HU, 22.7 ± 7.1 HU, P = 0.048) and mean effective dose (10.6 ± 5.9 mSv, 8.8 ± 5.0 mSv, P = 0.003) were significantly lower after implementation of ATVS.

CONCLUSIONS

Automated tube voltage selection can operator-independently optimize cardiovascular CTA image acquisition parameters with improved image quality at reduced dose.

KEY POINTS

• Automatic tube voltage selection optimizes tube voltage for each individual patient. • In this population, overall radiation dose decreased while image quality improved. • This tool may become valuable for improving dose/quality ratio.