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Rajiah PS, Dunning CAS, Rajendran K, Tandon Y, Ahmed Z, Larson N, Collins JD, Thorne J, Williamson E, Fletcher JG, McCollough C, Leng S. High-Pitch Multienergy Coronary CT Angiography in Dual-Source Photon-Counting Detector CT Scanner at Low Iodinated Contrast Dose. Invest Radiol 2023; 58:681-690. [PMID: 36822655 PMCID: PMC10591289 DOI: 10.1097/rli.0000000000000961] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
OBJECTIVES The aim of this study was to evaluate the high-helical pitch, multienergy (ME) scanning mode of a clinical dual-source photon-counting detector (PCD) computed tomography (CT) and the benefit of virtual monoenergetic images (VMIs) for low-contrast-dose coronary CT angiography (CTA). MATERIALS AND METHODS High-pitch (3.2) ME coronary CTA was performed in PCD-CT in 27 patients using low contrast dose (30 mL of iohexol 350 mg/mL) and in 26 patients at routine contrast dose (60 mL). Low-energy-threshold 120 kV images (also known as T3D images) and 50 kiloelectron volts (50 keV) and 100 kiloelectron volts (100 keV) VMIs were reconstructed using a 1024 × 1024 matrix and 0.6-mm slices. The CT numbers, noise, and contrast-to-noise ratio (CNR) were measured in the ascending aorta (AA), left main coronary artery (LMCA), and distal left anterior descending (LAD) artery. Confidence in grading luminal stenosis with calcific plaque, noncalcific plaque, and stent was evaluated by 2 independent readers on a 0-100 scale (0 the lowest), and a CAD-RADS score was assigned. Image contrast enhancement, sharpness, noise, artifacts, and overall image quality were rated using a 5-point ordinal scale (1 the lowest). RESULTS The radiation doses (CTDI) in low- and routine-contrast cohorts were 2.5 ± 0.6 mGy and 3.1 ± 1.7 mGy, respectively ( P = 0.12). At all measured locations, the mean CT number was >300 HU in 120 kV (LMCA 382.9 ± 76.2, distal LAD 341.0 ± 53.9, AA 399.5 ± 76.1) and 50 keV images (LMCA 667.5 ± 139.9, distal LAD 578.1 ± 121.5, AA 700.8 ± 142.5) in the low-contrast cohort, with a 96% increase in CT numbers for 50 keV over 120 kV. The CT numbers were significantly higher ( P < 0.0001) in 50 keV than 120 kV and 100 keV VMI. The CNR was also significantly ( P < 0.0001) higher in 50 keV than 120 kV and 100 keV images in all vessels. Confidence in the assessment of luminal stenosis in the presence of calcific plaque was significantly higher ( P = 0.001) with the addition of 100 keV VMI (median score, 100) than using 50 keV alone (median score, 70) and 120 kV (median score, 70) for reader 1, but no significant differences were seen for reader 2 who had same median scores of 100 for all image types. The confidence in the assessment of luminal stenosis within a stent improved with the use of 100 keV images for both readers (reader 1: median scores for 50 + 100 keV = 100, 50 keV = 82.5, 120 kV = 82.5; reader 2: 50 + 100 keV = 100, 50 keV = 90, 120 kV = 90). There were no significant differences in confidence scores for assessment of luminal stenosis from noncalcific plaques for both readers. The reader-averaged qualitative scores for vascular enhancement and overall image quality were significantly higher for 50 keV VMI than for 120 kV images in both low- and routine-contrast dose cohorts. The image sharpness was nonsignificantly higher at 50 keV VMI than 120 kV images, and the artifact score was comparable for 50 keV VMI and 120 kV images. The noise was higher in 50 keV VMI than in 120 kV images. CONCLUSIONS High-pitch ME PCD-CT mode produced diagnostic quality coronary CTA images at low radiation and iodinated contrast doses. The availability of ME VMIs significantly improved the CNR, overall image quality, and confidence in assessment of luminal stenosis in the presence of calcific plaques and stents, and resulted in change of CAD-RADS categories in 9 patients.
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Affiliation(s)
| | - Chelsea A. S. Dunning
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
| | - Kishore Rajendran
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
| | - Yasmeen Tandon
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
| | - Zaki Ahmed
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
| | - Nicholas Larson
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
| | - Jeremy D. Collins
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
| | - Jamison Thorne
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
| | - Eric Williamson
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
| | - Joel G. Fletcher
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
| | - Cynthia McCollough
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
| | - Shuai Leng
- Department of Radiology, Mayo Clinic, 200 First St SW Rochester, MN, United States 55905
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Kapoor A, Mahajan G, Kapoor A. Evaluation of Low-kVp Low-Volume Iodinated Contrast Protocol for Coronary CT Angiography Using Retrospective ECG Gating. Indian J Radiol Imaging 2022; 31:910-916. [PMID: 35136504 PMCID: PMC8817802 DOI: 10.1055/s-0041-1741102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Abstract
Objective The aim of this study was to evaluate the use of low peak kilovoltage (kVp) low-volume iodinated contrast protocol for performing coronary computed tomography (CT) angiography (CCTA) in patients using retrospective electrocardiogram (ECG) gating.
Materials and Methods Hundred prospective patients undergoing CCTA were studied in two groups, A and B, using 70 kilovoltage (kV) and 120 kV protocols with half and standard intravenous volumes of injected iodinated contrast, respectively. All patients had heart rates less than 100 beats/min and body mass index (BMI) less than 31 kg/m2. Both the groups were evaluated for signal-to-noise (S/N) and contrast-to-noise (C/N) ratios along with radiation dose delivered in millisievert (mSv), and for image quality (IQ), on per patient and per segment basis.
Results Patients with group A showed statistically reduced radiation dose of 1.86 mSv compared with 6.86 mSv in group B patients. Marked reduction in image noise with statistically improved S/N and C/N ratios in all coronary vessels was seen in group A. S/N ratios in group A were 20.25, 18.68, 19.04, 17.41, and 18.69 for aorta, left main, left anterior descending, right coronary, and left circumflex arteries while they were 13.34, 11.12, 10.96, 9.74, and 8.67 in group B patients. C/N ratios were also higher in all vessels in group A patients, that is, 19.48, 19.48, 19.04, 19.48, and 17.68, compared with group B patients, who had 12.43, 10.03, 9.23, 9.57, and 8.23 ratios (p < 0.0001). No significant difference in IQ per patient and per vessel was seen between both the groups.
Discussion Retrospective ECG-gated low-kVp low-volume iodinated contrast protocol provides good diagnostic quality angiograms in patients with BMI up to 31 kg/m2 and with heart rates of less than 100 beats/min with three times reduced radiation dose. The reduced volume of contrast reduces the cost as well as the chance of contrast-induced nephropathy.
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Affiliation(s)
- Atul Kapoor
- Advanced Diagnostics and Institute of Imaging, Amritsar, Punjab, India
| | - Goldaa Mahajan
- Advanced Diagnostics and Institute of Imaging, Amritsar, Punjab, India
| | - Aprajita Kapoor
- Advanced Diagnostics and Institute of Imaging, Amritsar, Punjab, India
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Finck T, Klambauer K, Hendrich E, Will A, Martinoff S, Hadamitzky M. Radiation Dose and Image Quality of a High-Pitch Prospective Spiral First Approach in Coronary Computed Tomography Angiography (CCTA). J Cardiovasc Dev Dis 2021; 8:jcdd8100119. [PMID: 34677188 PMCID: PMC8539421 DOI: 10.3390/jcdd8100119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/09/2021] [Accepted: 09/23/2021] [Indexed: 11/16/2022] Open
Abstract
Objective: To investigate a high-pitch spiral first (HPSF) approach for coronary computed tomography angiography (CCTA) in an unselected patient cohort and compare diagnostic yield and radiation exposure to CCTAs acquired via conventional, non-high-pitch spiral first (NHPSF) scan regimes. Materials and Methods: All consecutive patients from 1 January 2015 to 31 December 2017 were included. Two investigation protocols (HPSF/NHPSF) were used with the aim to achieve diagnostic image quality of all coronary segments. Low-pitch secondary scans followed the initial examination if image quality was unsatisfactory. Dosage and image quality were compared between both regimes. Results: 1410 patients were subject to a HPSF and 236 patients to a NHPSF approach. While the HPSF approach led to a higher fraction of re-scans (35% vs. 11%, p < 0.001), the fraction of aggregate scans that remained non-diagnostic after considering the initial and secondary scan was comparably low for the HPSF and NHPSF approach (0.78 vs. 0%, p = 0.18). Aggregate radiation exposure in the HPSF protocol was significantly lower (1.12 mSv (IQR: 0.73, 2.10) vs. 3.96 mSv (IQR: 2.23, 8.33) p < 0.001). Conclusions: In spite of a higher number of re-scans, a HPSF approach leads to a reduction in overall radiation exposure with diagnostic yields similar to a NHPSF approach.
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New-generation multidetector computed tomography technology for the management of congenital heart disease in children: Now we can! Rev Port Cardiol 2021; 40:591-593. [PMID: 34392903 DOI: 10.1016/j.repce.2021.07.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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António M. New-generation multidetector computed tomography technology for the management of congenital heart disease in children: Now we can! Rev Port Cardiol 2021. [DOI: 10.1016/j.repc.2021.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Lin ZX, Zhou F, Schoepf UJ, Pillai B, Zhou CS, Quan W, Bao XQ, Lu GM, Zhang LJ. Tube Voltage, DNA Double-Strand Breaks, and Image Quality in Coronary CT Angiography. Korean J Radiol 2020; 21:967-977. [PMID: 32677381 PMCID: PMC7369208 DOI: 10.3348/kjr.2019.0932] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 02/16/2020] [Accepted: 03/05/2020] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE To evaluate the effects of tube voltage on image quality in coronary CT angiography (CCTA), the estimated radiation dose, and DNA double-strand breaks (DSBs) in peripheral blood lymphocytes to optimize the use of CCTA in the era of low radiation doses. MATERIALS AND METHODS This study included 240 patients who were divided into 2 groups according to the DNA DSB analysis methods, i.e., immunofluorescence microscopy and flow cytometry. Each group was subdivided into 4 subgroups: those receiving CCTA only with different tube voltages of 120, 100, 80, or 70 kVp. Objective and subjective image quality was evaluated by analysis of variance. Radiation dosages were also recorded and compared. RESULTS There was no significant difference in demographic characteristics between the 2 groups and 4 subgroups in each group (all p > 0.05). As tube voltage decreased, both image quality and radiation dose decreased gradually and significantly. After CCTA, γ-H2AX foci and mean fluorescence intensity in the 120-, 100-, 80-, and 70-kVp groups increased by 0.14, 0.09, 0.07, and 0.06 foci per cell and 21.26, 9.13, 8.10, and 7.13 (all p < 0.05), respectively. The increase in the DNA DSB level in the 120-kVp group was higher than those in the other 3 groups (all p < 0.05), while there was no significant difference in the DSBs levels among these latter groups (all p > 0.05). CONCLUSION The 100-kVp tube voltage may be optimal for CCTA when weighing DNA DSBs against the estimated radiation dose and image quality, with further reductions in tube voltage being unnecessary for CCTA.
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Affiliation(s)
- Zhu Xiao Lin
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, China.,Department of Medical Imaging, Yantaishan Hospital, Yantai, China
| | - Fan Zhou
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - U Joseph Schoepf
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, China.,Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Balakrishnan Pillai
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA
| | - Chang Sheng Zhou
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Wei Quan
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Xue Qin Bao
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Guang Ming Lu
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Long Jiang Zhang
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, China.
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Application of Low Tube Voltage, Low-concentration Contrast Agent Using a 320-row CT in Coronary CT Angiography: Evaluation of Image Quality, Radiation Dose and Iodine Intake. Curr Med Sci 2020; 40:178-183. [PMID: 32166681 DOI: 10.1007/s11596-020-2162-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 12/15/2019] [Indexed: 10/24/2022]
Abstract
The effect of low voltage and low concentration contrast agent on image quality of coronary CT angiography, radiation dose and iodine intake was evaluated. A total of 121 patients with body mass index (BMI) <26 kg/m2 and heart rate (HR) <70 beats/min were randomly divided into four groups: group A (n=31, 80 kVp, 270 mgI/mL); group B (n=33, 100 kVp, 270 mgI/mL); group C (n=30, 100 kVp, 320 mgI/mL); group D (n=27, 100 kVp, 400 mgI/mL). The automatic current modulation system and the iterative algorithm for reconstruction were adopted in each group. The CT values and SD values of the aortic root (AR), subcutaneous fat, left coronary artery opening (LCA), and right coronary artery opening (RCA) were measured in all groups, the signal-to-noise ratio (SNR) and contrast noise ratio (CNR) were calculated, and effective radiation dose and iodine intake were recorded. The subjective assessment for image quality was performed by two physicians using a 4-point scale. The results were compared using the one-way ANOVA and rank sum tests. The image quality of the four groups met the clinical diagnostic requirements. The CT values of AR in groups A, B, C, and D were 537.6±71.4, 447.2±81.9, 445.2±64.9 and 518.5±94.9 Hu, respectively, with no significant difference between group A and group D, or between group B and group C, while CT values in groups B and C were significantly lower than those in groups A and D (P<0.05). In groups A, B, C, and D, the LCA SNR values were 22.7±9.1, 23.3±9.1, 23.3±7.7 and 26.6±8.9, and the RCA CNR values were 26.9±9.8, 28.5±11.4, 27.7±8.8 and 32.1±10.6, respectively. The AR visual scores in groups A, B, C and D were 3.8±0.2, 3.9±0.3, 3.9±0.3 and 4.0±0.3, respectively. There were no significant differences in SNR, CNR and visual score among the four groups (P>0.05). The radiation doses in groups A, B, C and D were 2.6±1.4, 3.6±1.8, 4.9±3.5 and 4.9±2.8 mSv, respectively. The radiation dose in group A was significantly less than that in the rest three groups (P<0.05). The iodine intakes in groups A, B, C and D were 14.9±1.5, 15.0±1.5, 17.7±2.0 and 18.1±2.5 g, respectively. There was no significant difference in the intake of iodine between groups C and D, or between groups A and B, while iodine intake in groups A and B were significantly reduced as compared with that in groups C and D (P<0.05). It was concluded that for patients with low BMI and controlled HR, compared to 100 kVp tube voltage combined with multiple concentration contrast agents, 80 kVp combined with 270 mgI/mL contrast agent is enough to ensure the quality of the images, and can reduce the radiation dose significantly, while reducing the amount of iodine intake notably, thus reducing the incidence of adverse reaction.
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Chan S, Giles E, Newmarch L, Short M. Effect of patient size on image quality in radiotherapy kV planar verification imaging: a phantom study. J Med Radiat Sci 2019; 67:34-42. [PMID: 31621206 PMCID: PMC7063253 DOI: 10.1002/jmrs.355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 08/08/2019] [Accepted: 08/10/2019] [Indexed: 01/10/2023] Open
Abstract
INTRODUCTION This study aimed to determine a maximal pelvic separation and waist circumference in pelvic patients to guide radiation therapists in acquiring kilovoltage (kV) planar images of acceptable quality for treatment verification. METHODS A pelvic anthropomorphic phantom modified with different bolus thicknesses was imaged at various default kV exposure settings. Radiation therapists rated image quality and acceptance/rejection of these images for treatment verification. RESULTS Sixteen radiation therapists participated in the study. Image quality was inversely proportional to phantom size. AP and lateral kV images were acceptable for treatment verification up to a waist circumference of 143 cm. CONCLUSIONS Exposure settings for kV image verification of large patients should be individualised to avoid unnecessary patient radiation dose through repeated imaging.
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Affiliation(s)
- Sara Chan
- Centre for Translational Cancer Research, UniSA Cancer Research Institute and School of Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Eileen Giles
- Centre for Translational Cancer Research, UniSA Cancer Research Institute and School of Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Lyndal Newmarch
- Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Michala Short
- Centre for Translational Cancer Research, UniSA Cancer Research Institute and School of Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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Zhao L, Bao J, Guo Y, Li J, Yang X, Lv T, Hao F, Wang Z, Yang Z, Liu A. Ultra-low dose one-step CT angiography for coronary, carotid and cerebral arteries using 128-slice dual-source CT: A feasibility study. Exp Ther Med 2019; 17:4167-4175. [PMID: 30988794 PMCID: PMC6447913 DOI: 10.3892/etm.2019.7420] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 03/07/2019] [Indexed: 12/19/2022] Open
Abstract
Atherosclerotic diseases are systemic and patient outcomes depend on comprehensive imaging evaluation. Computed tomography angiography (CTA) is a powerful tool used to assess atherosclerosis. However, the scanning protocol is designed for cardiovascular and cerebrovascular imaging, which require considerations into the radiation dose, contrast agent and image quality. The purpose of the present study was to evaluate ultra-low dose one-step CTA for coronary, carotid and cerebral arteries with a low concentration contrast agent. A total of 78 patients were enrolled and randomly divided into two groups: Group A (n=38) and B (n=40). High-pitch CTA for coronary, carotid and cerebral arteries with a tube voltage of 70 or 80 kVp and 40 ml contrast agent (270 mgI/ml) was performed by a 128-slice dual-source CT scanner for group A. Standard high-pitch CTA with a tube voltage of 100 kVp and 60 ml contrast agent (370 mgI/ml) was conducted for group B. The image quality, radiation dose and amount of contrast agent in group A were evaluated and compared with group B. The dose length product for groups A and B was 62.95±21.54 vs. 160.15±15.13 mGy cm, respectively (t=−23.157, P<0.001). The mean total iodine content was 10.8±0 mg for group A and 22.2±0 mg for group B. In total, 99.4% of the arterial segments could be assessed for the two groups (χ2=0.267, P=0.606). The results revealed that ultra-low dose one-step high-pitch CTA can provide assessable image quality, and minimize the radiation dose and contrast agent.
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Affiliation(s)
- Lei Zhao
- Department of Radiology, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot, Inner Mongolia 010050, P.R. China
| | - Jiaqi Bao
- Department of Cardiology, Inner Mongolia People's Hospital, Hohhot, Inner Mongolia 010020, P.R. China
| | - Youmin Guo
- Department of Radiology, The Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Jianbo Li
- Department of Radiology, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot, Inner Mongolia 010050, P.R. China
| | - Xiaoguang Yang
- Department of Radiology, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot, Inner Mongolia 010050, P.R. China
| | - Tiegang Lv
- Department of Radiology, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot, Inner Mongolia 010050, P.R. China
| | - Fen'E Hao
- Department of Radiology, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot, Inner Mongolia 010050, P.R. China
| | - Zefeng Wang
- Department of Radiology, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot, Inner Mongolia 010050, P.R. China
| | - Zhenxing Yang
- Department of Radiology, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot, Inner Mongolia 010050, P.R. China
| | - Aishi Liu
- Department of Radiology, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot, Inner Mongolia 010050, P.R. China
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Image quality and diagnostic value of ultra low-voltage, ultra low-contrast coronary CT angiography. Eur Radiol 2019; 29:3678-3685. [DOI: 10.1007/s00330-019-06111-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 01/28/2019] [Accepted: 02/13/2019] [Indexed: 10/27/2022]
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Qu TT, Li JY, Jiao XJ, Zhang XL, Song ZF, Guo YX, Guo JX. Contrast dose reduction with shortened injection durations in coronary CT angiography on 16-cm Wide-detector CT scanner. Br J Radiol 2018; 91:20180580. [PMID: 30160183 PMCID: PMC6319827 DOI: 10.1259/bjr.20180580] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 08/12/2018] [Accepted: 08/14/2018] [Indexed: 01/11/2023] Open
Abstract
OBJECTIVES: To investigate the use of shortened contrast injection with late triggering in coronary CT angiography (CCTA) for decreasing contrast dose and maintaining image quality. METHODS: 106 patients for CCTA on a 16-cm wide-detector CT were prospectively enrolled into groups A (n = 50) and B (n = 56) randomly. Patient weight-dependent contrast medium (Iopamiro, 370 mgI ml-1) at dose rate of 25 mgI/kg/s was used with 8 s and the standard 10 s injection time in groups A and B, respectively. CT values of the aortic sinus (AS), right coronary artery, left anterior descending and left circumflex at the proximal, middle and distal segments were measured and compared. Subjective image quality was evaluated and analyzed with Fisher exact test. Contrast dose, injection rate and enhancement duration (between the start of enhancement in AS and scan finish) were also compared. RESULTS: There was no difference in the injection rate and enhancement duration between the two groups (p > 0.05), while the total contrast dose in group A (36.2 ± 5.7 ml) was significantly lower than in group B (46.4 ± 6.3 ml) (p < 0.001). There was no difference for CT values in all major coronary vessels between the two groups and no difference in subjective image quality scores (all p > 0.05). CONCLUSION: It is feasible to shorten contrast injection to 8 s in CCTA on wide-detector CT systems to significantly reduce contrast dosage, maintain adequate enhancement and reduce contrast-related artifacts. ADVANCES IN KNOWLEDGE: (1) Coronary CT angiography (CCTA) scans with shortened contrast medium injection duration and late triggering are feasible with a 16-cm wide-detector CT system (2) Compared with the conventional CCTA with 10 s contrast injection duration, the new contrast injection protocol of using shortened injection duration (to 8 s) and late triggering reduces contrast dose to 36.2 ml, while maintaining adequate enhancement in vessels and reducing contrast-related artifacts.
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Affiliation(s)
- Ting-ting Qu
- Department of Radiology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi'an, PR China
| | - Jian-ying Li
- CT Research Center, GE Healthcare China, Beijing, China
| | - Xi-jun Jiao
- Department of Radiology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi'an, PR China
| | - Xiang-li Zhang
- Department of Radiology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi'an, PR China
| | - Zhe-fan Song
- Department of Radiology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi'an, PR China
| | - Yin-xia Guo
- Department of Radiology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi'an, PR China
| | - Jian-xin Guo
- Department of Radiology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi'an, PR China
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Chen Y, Liu Z, Li M, Yu Y, Jia Y, Ma G, Hu Z, Wei D, Li D, He T. Reducing both radiation and contrast doses in coronary CT angiography in lean patients on a 16-cm wide-detector CT using 70 kVp and ASiR-V algorithm, in comparison with the conventional 100-kVp protocol. Eur Radiol 2018; 29:3036-3043. [PMID: 30506217 DOI: 10.1007/s00330-018-5837-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 09/28/2018] [Accepted: 10/17/2018] [Indexed: 01/17/2023]
Abstract
OBJECTIVE To investigate the value of prospectively ECG-triggered coronary CT angiography (CCTA) for lean patients with body mass index (BMI) ≤ 23 kg/m2 using 70 kVp and high-level volume-based adaptive statistical iterative reconstruction (ASiR-V) algorithm on a 16-cm wide-detector CT system for reducing both radiation and contrast doses in comparison with the conventional 100-kVp protocol. MATERIALS AND METHODS Thirty patients (group A) were prospectively enrolled to undergo 70-kVp CCTA on a 16-cm wide-detector CT scanner with noise index (NI) of 36 HU and at weight-dependent contrast dose rate of 16 mg I/kg/s for 9-s injection. Images were reconstructed with 80% ASiR-V. Radiation dose, contrast dose, and image quality were statistically compared with 30 patients (group B) in database with matching BMI who underwent conventional 100-kVp CCTA with NI of 25 HU, and at 25 mg I/kg/s rate for 10-s injection and reconstructed with 60% ASiR-V. RESULTS There was no significant difference in patient demographics between the two groups (all p > 0.05). The two groups also had similar mean CT values and contrast-noise ratio (CNR) and subjective image quality (all p > 0.05). However, group A with 70 kVp reduced the effective dose by 75.3% compared with group B (0.43 ± 0.20 mSv vs. 1.74 ± 1.01 mSv, p < 0.001), and required 42.4% less contrast dose than group B (22.46 ± 2.94 ml vs. 38.99 ± 5.10 ml, p < 0.001). CONCLUSIONS Prospectively ECG-triggered CCTA using 70 kVp and high-level ASiR-V on a 16-cm wide-detector CT system provides diagnostic images with substantial reduction in both radiation and contrast doses for patients with BMI ≤ 23 kg/m2 compared to the conventional 100-kVp protocol. KEY POINTS • 70-kVp CCTA produces excellent images at sub-millisievert radiation. • 70-kVp CCTA reduces both radiation and contrast doses over conventional protocol. • Achieving low-dose CCTA with combined low kVp and high-level ASIR-V.
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Affiliation(s)
- Yuhuan Chen
- Shaanxi University of Chinese Medicine, Xianyang, 712000, China
- Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, 712000, China
| | - Zhentang Liu
- Department of Radiology, Chang'an Hospital, Xi'an, 710018, Shaanxi, China
| | | | - Yong Yu
- Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, 712000, China
| | - Yongjun Jia
- Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, 712000, China
| | - Guangming Ma
- Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, 712000, China
| | - Zhijun Hu
- Department of Radiology, Chang'an Hospital, Xi'an, 710018, Shaanxi, China
| | - DongHong Wei
- Department of Radiology, Chang'an Hospital, Xi'an, 710018, Shaanxi, China
| | - Dou Li
- Department of Radiology, Chang'an Hospital, Xi'an, 710018, Shaanxi, China
| | - Taiping He
- Shaanxi University of Chinese Medicine, Xianyang, 712000, China.
- Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, 712000, China.
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Forte E, Monti S, Parente CA, Beyer L, De Rosa R, Infante T, Cavaliere C, Cademartiri F, Salvatore M, Stroszczynski C, Tedeschi C. Image Quality and Dose Reduction by Dual Source Computed Tomography Coronary Angiography: Protocol Comparison. Dose Response 2018; 16:1559325818805838. [PMID: 30349426 PMCID: PMC6194939 DOI: 10.1177/1559325818805838] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 09/06/2018] [Accepted: 09/18/2018] [Indexed: 01/18/2023] Open
Abstract
Purpose: To compare image quality and radiation dose among different protocols in patients who underwent a 128-slice dual source computed tomography coronary angiography (DSCT-CTCA). Methods: Ninety patients were retrospectively grouped according to heart rate (HR): 26 patients (group A) with stable HR ≤60 bpm were acquired using high pitch spiral mode (FLASH); 48 patients (group B) with irregular HR ≤60 bpm or stable HR between 60 and 70 bpm using step and shoot mode; and 16 patients (group C) with irregular HR >60 bpm or stable HR ≥70 bpm by retrospective electrocardiogram pulsing acquisition. Signal to noise ratio (SNR) and contrast to noise ratio (CNR) were measured for the main vascular structures. Moreover, the dose-length product and the effective dose were assessed. Results: Both SNR and CNR were higher in group A compared to group C (18.27 ± 0.32 vs 11.22 ± 0.50 and 16.75 ± 0.32 vs 10.17 ± 0.50; P = .001). The effective dose was lower in groups A and B (2.09 ± 1.27 mSv and 4.60 ± 2.78 mSv, respectively) compared to group C (9.61 ± 5.95 mSv) P < .0001. Conclusion: The correct selection of a low-dose, HR-matched CTCA scan protocol with a DSCT scanner provides substantial reduction of radiation exposure and better SNR and CNR.
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Affiliation(s)
| | | | | | - Lukas Beyer
- Department of Radiology, Universitätsklinikum Regensburg, Regensburg, Germany
| | | | | | | | | | | | | | - Carlo Tedeschi
- Department of Radiology, Universitätsklinikum Regensburg, Regensburg, Germany.,P.S.I. Napoli Est, ASL Napoli 1 Centro, Naples, Italy
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Abstract
Cardiovascular CT (CCT) is an important imaging modality in congenital and acquired paediatric heart disease. Technological advances have resulted in marked improvements in spatial and temporal resolution of CCT with a concomitant increase in speed of data acquisition and a decrease in radiation dose. This has elevated CCT from being sparingly used to an essential diagnostic tool in the daily multimodality imaging practice alongside echocardiography, cardiovascular MR and invasive angiography. The application of CCT in paediatric congenital and acquired heart disease can be both technically and diagnostically challenging. This review highlights important considerations for current state of the art CCT across the spectrum of heart disease encountered in children.
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Affiliation(s)
- Kristian H Mortensen
- 1 Cardiorespiratory Unit, Great Ormond Street Hospital for Children NHS Foundation Trust , London , UK
| | - Oliver Tann
- 1 Cardiorespiratory Unit, Great Ormond Street Hospital for Children NHS Foundation Trust , London , UK
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Wang C, Liao Y, Chen H, Zhen X, Li J, Xu Y, Zhou L. Influence of tube potential on quantitative coronary plaque analyses by low radiation dose computed tomography: a phantom study. Int J Cardiovasc Imaging 2018; 34:1315-1322. [PMID: 29582238 DOI: 10.1007/s10554-018-1344-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 03/22/2018] [Indexed: 12/18/2022]
Abstract
Previous studies have shown that employing the low dose computed tomography (CT) technique based on low tube potential reduces the radiation dose required for the coronary artery examination protocol. However, low tube potential may adversely influence the CT number of plaque composition. Therefore, we aimed to determine whether quantitative atherosclerotic plaque analysis by a multi-slice, low radiation dose CT protocol using 80 kilovolts (kV) yields results comparable to those of the standard 120 kV protocol. Artificial plaque samples (n = 17) composed of three kinds of plaque were scanned at 120 and 80 kV. Relative low-density and medium-density plaque component volumes obtained by three protocols (80 kV, 60 Hounsfield units [HU] threshold; 120 kV, 60 HU threshold; and 80 kV, 82 HU threshold) were compared. Using the 60 HU threshold, relative volume of the low-density plaque component obtained at 80 kV was lower than that obtained at 120 kV (27 ± 3% vs. 51 ± 5%, P < 0.001), whereas relative volume of the medium-density plaque component obtained at 80 kV was higher than that obtained at 120 kV (73 ± 3% vs. 48 ± 5%, P < 0.001). By contrast, no significant difference in relative volume obtained at 80 kV (82 HU threshold) versus 120 kV (60 HU threshold) was observed for either low-density (52 ± 5% vs. 51 ± 5%) or medium-density (48 ± 5% vs. 48 ± 5%) plaque component. Low tube potential may affect the accuracy of quantitative atherosclerotic plaque analysis. For our phantom test, 82 HU was the optimal threshold for scanning at 80 kV.
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Affiliation(s)
- Chunhong Wang
- Department of Radiology, Xinyang Central Hospital, Xinyang, 464002, Henan, China
| | - Yuliang Liao
- Department of Biomedical Engineering, Southern Medical University, Guangzhou, 510515, Guangdong, China
| | - Haibin Chen
- Department of Biomedical Engineering, Southern Medical University, Guangzhou, 510515, Guangdong, China
| | - Xin Zhen
- Department of Biomedical Engineering, Southern Medical University, Guangzhou, 510515, Guangdong, China
| | - Jianhong Li
- Department of Radiology, Xinyang Central Hospital, Xinyang, 464002, Henan, China
| | - Yikai Xu
- Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, No. 1838 Guangzhou Avenue North, Guangzhou, 510515, Guangdong, China.
| | - Linghong Zhou
- Department of Biomedical Engineering, Southern Medical University, Guangzhou, 510515, Guangdong, China.
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High-Pitch Coronary Computed Tomographic Angiography Using the Third-Generation Dual-Source Computed Tomography. J Comput Assist Tomogr 2018; 42:248-255. [DOI: 10.1097/rct.0000000000000678] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Takahashi Y, Ota H, Omura K, Dendo Y, Otani K, Matsuura T, Kitami M, Seiji K, Tezuka Y, Nezu M, Ono Y, Morimoto R, Satoh F, Takase K. Image quality and radiation dose of low-tube-voltage CT with reduced contrast media for right adrenal vein imaging. Eur J Radiol 2017; 98:150-157. [PMID: 29279155 DOI: 10.1016/j.ejrad.2017.11.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 11/15/2017] [Accepted: 11/24/2017] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To compare image quality and radiation dose of right adrenal vein (RAV) imaging computed tomography (CT) among conventional, low kV, and low kV with reduced contrast medium protocols. METHODS One-hundred-and-twenty patients undergoing adrenal CT were randomly assigned to one of three protocols: contrast dose of 600mgI/kg at 120-kV tube voltage setting (600-120 group), 600mgI/kg at 80kV (600-80 group), and 360mgI/kg at 80kV (360-80 group). Iterative reconstruction was used for 80-kV groups. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the RAV and size-specific dose estimates (SSDE) were measured. Three radiologists evaluated 4-point visualisation scores of RAV by consensus reading. RESULTS The RAV detectability was 95%, 97.2%, and 97.3% for 600-120, 600-80, and 360-80 groups, respectively (p=1.000). Visualisation scores were not significantly different among the groups (p=0.152). There were no significant differences in CNR or SNR between the 600-120 and 360-80 groups. SSDE of the 360-80 group was significantly lower than that of the 600-120 group (5.86mGy±1.44 vs. 7.27mGy±1.81, p<0.001). CONCLUSIONS 80-kV scans with 360 mgI/kg contrast media showed comparable detectability of RAV to conventional scans, while reducing 19% of SSDE.
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Affiliation(s)
- Yuki Takahashi
- Department of Diagnostic Radiology, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Hideki Ota
- Department of Diagnostic Radiology, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.
| | - Kensuke Omura
- Department of Diagnostic Radiology, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Yutaka Dendo
- Department of Diagnostic Radiology, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Katharina Otani
- Diagnostic Imaging Business Area, DI Research & Collaboration Department, Siemens Healthcare KK, Gate City Osaki West Tower, 1-11-1, Osaki, Shinagawa-ku, Tokyo, 141-8644, Japan
| | - Tomonori Matsuura
- Department of Diagnostic Radiology, Tohoku Medical and Pharmaceutical University Hospital, 1-12-1 Fukumuro, Miyagino-ku, Sendai 983-8512, Japan
| | - Masahiro Kitami
- Department of Diagnostic Radiology, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Kazumasa Seiji
- Department of Diagnostic Radiology, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Yuta Tezuka
- Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Masahiro Nezu
- Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Yoshikiyo Ono
- Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Ryo Morimoto
- Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Fumitoshi Satoh
- Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Kei Takase
- Department of Diagnostic Radiology, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
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Zhao L, Liu A, Guo Y. Ultra-low-dose CT coronary angiography using 128-slice dual source CT with low concentration contrast agent: initial experience. Jpn J Radiol 2017; 35:724-732. [PMID: 29052025 DOI: 10.1007/s11604-017-0688-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 09/27/2017] [Indexed: 02/07/2023]
Abstract
PURPOSE To optimize and evaluate an ultra-low-dose (ULD) technique for CT coronary angiography (CTCA). MATERIALS AND METHODS Eighty-two patients were randomly divided into two groups. ULD and routine CTCA were performed in groups A and B. Image quality, radiation dose and contrast agent were evaluated. RESULTS The effective dose (ED) was 0.20 ± 0.01 mSv for the ULD technique, a decrease of 87% (t = - 21.182, P < 0.001) compared with the control group. The total iodine content was 8.10 ± 0 g, a decrease of 62% (t = - 73.458, P < 0.001) compared with 21.10 ± 1.15 g for the control group. The assessment rates for both groups were the same (99.26 vs 99.64%, χ 2 = 0.727, P = 0.394). The contrast-to-noise ratio was 19.31 ± 7.95 for group A and 20.73 ± 5.07 for group B: the difference was not statistically significant (t = - 1.678, P = 0.095). CONCLUSION Using an ultra-low radiation dose and contrast agent technique, while maintaining an assessable image and improving the safety of the medical examination, was a feasible and reliable method for CTCA.
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Affiliation(s)
- Lei Zhao
- Department of Radiology, The First Affiliated Hospital Of Xi'an Jiaotong University, No. 277 Yanta West Street, Xi'an, 710061, Shanxi, China.,Department of Radiology, The Affiliated Hospital of Inner Mongolia Medical University, No. 1 Tongdao North Street, Hohhot, 010050, Inner Mongolia, China
| | - Aishi Liu
- Department of Radiology, The Affiliated Hospital of Inner Mongolia Medical University, No. 1 Tongdao North Street, Hohhot, 010050, Inner Mongolia, China
| | - Youmin Guo
- Department of Radiology, The First Affiliated Hospital Of Xi'an Jiaotong University, No. 277 Yanta West Street, Xi'an, 710061, Shanxi, China.
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Scan time adapted contrast agent injection protocols with low volume for low-tube voltage CT angiography: An in vitro study. Eur J Radiol 2017; 93:65-69. [DOI: 10.1016/j.ejrad.2017.05.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 05/11/2017] [Accepted: 05/16/2017] [Indexed: 11/20/2022]
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Feng R, Tong J, Liu X, Zhao Y, Zhang L. High-Pitch Coronary CT Angiography at 70 kVp Adopting a Protocol of Low Injection Speed and Low Volume of Contrast Medium. Korean J Radiol 2017; 18:763-772. [PMID: 28860894 PMCID: PMC5552460 DOI: 10.3348/kjr.2017.18.5.763] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 02/22/2017] [Indexed: 11/15/2022] Open
Abstract
Objective To evaluate the feasibility and image quality (IQ) of prospectively high-pitch coronary CT angiography (CCTA) with low contrast medium injection rate at 70 kVp. Materials and Methods One hundred and four patients with suspected coronary artery disease (body mass index < 26 kg/m2, sinus rhythm and heart rate < 70 beats/min) were prospectively enrolled and randomly divided into two groups. In group A and group B, 28 mL and 40 mL of 370 mgI/mL iodinated contrast media was administrated at a flow rate of 3.5 and 5 mL/s, respectively. CT values, noise, signal-to-noise ratio, contrast-to-noise ratio (CNR) of the proximal segments of coronary arteries and subjective IQ were evaluated. Results The CT values and noise in group A were significantly lower than those in group B (434–485 Hounsfield units [HU] vs. 772–851 HU, all p < 0.001; 17.8–22.3 vs. 23.3–26.4, all p < 0.005). The CNRs of the right coronary artery and left main artery showed no statistical difference between the two groups (42.1 ± 13.8 vs. 36.8 ± 16.0, p = 0.074; 38.7 ± 10.6 vs. 38.1 ± 17.0, p = 0.819). No statistical difference was observed between the two groups in IQ scores (3.04 ± 0.75 vs. 3.0 ± 0.79, p = 0.526) and diagnostic ratio (96.1% [50/52] vs. 94.2% [49/52], p = 0.647). Conclusion Prospective high-pitch CCTA at 70 kVp with 28 mL of contrast media and injection rate of 3.5 mL/s could provide diagnostic IQ for normal-weight patients with heart rate of < 70 beats/min.
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Affiliation(s)
- Ruiqi Feng
- Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang 110001, P.R. China
| | - Jiajie Tong
- Department of Radiology, Hebei General Hospital, Shijiazhuang 050051, P.R. China
| | - Xiaofei Liu
- Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang 110001, P.R. China
| | - Yu Zhao
- Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang 110001, P.R. China
| | - Liang Zhang
- Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang 110001, P.R. China
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Prospectively ECG-triggered high-pitch coronary CT angiography at 70 kVp with 30mL contrast agent: An intraindividual comparison with sequential scanning at 120 kVp with 60mL contrast agent. Eur J Radiol 2017; 90:97-105. [PMID: 28583653 DOI: 10.1016/j.ejrad.2017.02.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 01/03/2017] [Accepted: 02/14/2017] [Indexed: 11/24/2022]
Abstract
PURPOSE To investigate image quality, radiation dose, and diagnostic efficiency of prospectively ECG-triggered high-pitch coronary CT angiography (CCTA) at 70 kVp with 30mL contrast agent intra-individually compared with routine CCTA protocol. MATERIALS AND METHODS One hundred and thirty eight patients with suspected coronary artery disease, body mass index (BMI)≤25kg/m2 and heart rate (HR)≤70 beats per minute (bpm) underwent prospectively ECG-triggered high-pitch CCTA at 70 kVp and 30mL contrast agent (protocol A) and prospectively ECG-triggered sequential scanning at 120 kVp and 60mL contrast medium (protocol B). Objective and subjective image quality, radiation doses, and diagnostic accuracy were evaluated and compared between the two protocols. RESULTS Higher CT attenuation, higher noise, lower signal-to-noise ratios (SNRs) and lower contrast-to-noise ratios (CNRs) were found in protocol A than in protocol B (P<0.001). However, image quality of protocol A were diagnostic. In patients with BMI<23kg/m2 or HR<60bpm, subjective image quality scores of some coronary arteries in protocol A were not significantly different from protocol B (P>0.05). Effective dose in protocol A has reduced by 96.7% compared with protocol B (P<0.001). No significant differences were found for diagnostic accuracy between the two protocols on a per-segment (P=0.513), per-vessel (P=0.317) and per-patient (P=0.125) basis. CONCLUSIONS Prospectively ECG-triggered high-pitch CCTA at 70kVp with 30mL contrast agent can reduce radiation dose but maintain image quality and high diagnostic accuracy in a selected, non-obese population.
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Chahal H, Levsky JM, Garcia MJ. Cardiac CT: present and future applications. BRITISH HEART JOURNAL 2016; 102:1840-1850. [DOI: 10.1136/heartjnl-2015-307481] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Shen Y, Hu X, Zou X, Zhu D, Li Z, Hu D. Did low tube voltage CT combined with low contrast media burden protocols accomplish the goal of "double low" for patients? An overview of applications in vessels and abdominal parenchymal organs over the past 5 years. Int J Clin Pract 2016; 70 Suppl 9B:B5-B15. [PMID: 27577514 DOI: 10.1111/ijcp.12861] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 06/15/2016] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Imaging communities have already reached a consensus that the radiation dose of computed tomography (CT) should be reduced as much as reasonably achievable to lower population risks. Increasing attention is being paid to iodinated contrast media (CM) induced nephrotoxicity (CIN); a decrease in the intake of iodinated CM is required by increasingly more radiologists. Theoretically, the radiation dose varies with the tube current time and square of the tube voltage, with higher iodine contrast at low photon energies (Huda et al. [2000] Radiology, 21 7, 430-435).The use of low tube voltage is a promising strategy to reduce both the radiation dose and CM burden. The term 'double low' has been coined to describe scanning protocols that reduce radiation dose and iodine intake synchronously. These protocols are becoming increasingly popular in the clinical setting. PURPOSE The aim of this review was to describe all original studies using the 'double low' strategy in the last 5 years. METHODS We searched an online electronic database (PubMed) from January 2011 to December 2015 for original studies published on the relationship of low tube voltage with low radiation dose and low iodine contrast media burden in patients undergoing CT scans. Studies that failed to reduce radiation dose or iodine CM burden were excluded in this study. RESULTS Thirty-seven studies aimed at reducing radiation dose using low tube voltage combined with iodine CM reduced protocols were included in this study. Most studies evaluated conditions associated with arteries. Four were cerebral and neck computed tomography angiography (CTA) studies, 15 were pulmonary CTA (pCTA) and coronary CTA (cCTA) studies, one concerned myocardial perfusion, five studies focused on the thoracic and abdominal aorta, and one investigated renal arteries. Three studies consisted of CT venography (CTV) of the pelvis and lower extremities. Six publications examined the liver, and two focused on the kidney. CONCLUSION Overall, this review demonstrates that the low tube voltage CT protocol is a powerful tool to reduce the radiation dose in CTA, especially with pCTA and cCTA.
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Affiliation(s)
- Yaqi Shen
- Departments of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Xuemei Hu
- Departments of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Xianlun Zou
- Departments of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Di Zhu
- Departments of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Zhen Li
- Departments of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Daoyu Hu
- Departments of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
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MacDougall RD, Kleinman PL, Yu L, Lee EY. Pediatric thoracic CT angiography at 70 kV: a phantom study to investigate the effects on image quality and radiation dose. Pediatr Radiol 2016; 46:1114-9. [PMID: 26987734 DOI: 10.1007/s00247-016-3588-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 01/13/2016] [Accepted: 02/16/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND Studies have demonstrated that 70-kilovolt (kV) imaging enhances the contrast of iodine, potentially affording a reduction in radiation dose while maintaining the contrast-to-noise ratio (CNR). There is a maximum amount of image noise beyond which increased contrast does not improve structure visualization. Thus, noise should be constrained during protocol optimization. OBJECTIVE This phantom study investigated the effect of 70-kV imaging for pediatric thoracic CT angiography on image quality and radiation dose in a pediatric population when a noise constraint was considered. MATERIALS AND METHODS We measured contrast and noise using anthropomorphic thoracic phantoms ranging in size from newborn age equivalent to 10-year-old age equivalent. We inserted contrast rods into the phantoms to simulate injected contrast material used in a CT angiography study. The image-quality metric "iodine CNR with a noise constraint" was used to determine the relative dose factor for each phantom size, kV setting (70-140 kV) and noise constraint (1.00-1.20). A noise constraint of 1.20 indicates that noise should not increase by more than 20% of the noise level in images performed at the reference kV, selected to be 80 kV in this study. The relative dose factor can be applied to the original dose obtained at 80 kV in order to maintain iodine CNR with the noise constraint. A relative dose factor <1.0 indicates potential for dose reduction while a relative dose factor >1.0 indicates a dose penalty. RESULTS Iodine contrast was highest for 70 kV and decreased with higher kV settings for all phantom sizes. The relative dose factor at 70 kV was <1.0 for all noise constraint >1.0, indicating potential for dose reduction, for the newborn, 1-year-old and 5-year-old age-equivalent phantom sizes. For the 10-year-old age-equivalent phantom, relative dose factor at 70 kV=1.22, 1.11, 1.01, 0.92 and 0.83 for noise constraint=1.00, 1.05, 1.10, 1.15, 1.20, respectively, indicating a dose penalty for noise constraint ≤1.10 and potential for dose reduction for noise constraint >1.10. CONCLUSION Using 70 kV does allow for radiation dose reduction if the radiologist is willing to accept a higher level of image noise as a trade-off for increased vessel contrast. This increase in noise is small (<5%) for the nominal newborn, 1- and 5-year-old but is >10% for the 10-year-old. Therefore, we recommend limiting 70 kV thoracic CT angiography to newborn through 5-year-old patients.
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Affiliation(s)
- Robert D MacDougall
- Department of Radiology, Harvard Medical School, Boston Children's Hospital, 300 Longwood Ave., Boston, MA, 02115, USA.
| | - Patricia L Kleinman
- Department of Radiology, Harvard Medical School, Boston Children's Hospital, 300 Longwood Ave., Boston, MA, 02115, USA
| | - Lifeng Yu
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | - Edward Y Lee
- Department of Radiology, Harvard Medical School, Boston Children's Hospital, 300 Longwood Ave., Boston, MA, 02115, USA
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Non–Electrocardiogram-Triggered 70-kVp High-Pitch Computed Tomography Angiography of the Whole Aorta With Iterative Reconstruction. J Comput Assist Tomogr 2016; 40:109-17. [DOI: 10.1097/rct.0000000000000329] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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70-kVp High-pitch Computed Tomography Pulmonary Angiography with 40 mL Contrast Agent: Initial Experience. Acad Radiol 2015; 22:1562-70. [PMID: 26432073 DOI: 10.1016/j.acra.2015.08.026] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 05/25/2015] [Accepted: 08/23/2015] [Indexed: 12/11/2022]
Abstract
RATIONALE AND OBJECTIVES To assess image quality, radiation dose, and diagnostic accuracy of 70-kVp high-pitch computed tomography pulmonary angiography (CTPA) using 40 mL contrast agent and sinogram affirmed iterative reconstruction (SAFIRE) compared to 100-kVp CTPA using 60 mL contrast agent and filtered back projection. MATERIALS AND METHODS Eighty patients underwent CTPA at either 70 kVp (group A, n = 40; 3.2 pitch, 40 mL contrast medium, and SAFIRE) or 100 kVp (group B, n = 40; 1.2 pitch, 60 mL contrast medium, and filtered back projection). Signal-to-noise ratio and contrast-to-noise ratio were calculated. Subjective image quality was evaluated using a five-grade scale, and diagnostic accuracy was assessed. Radiation doses were compared. RESULTS Computed tomography values, signal-to-noise ratio, and contrast-to-noise ratio of pulmonary arteries were higher in group A compared to group B (all P < 0.001). Subjective image quality showed no difference between the two groups (P = 0.559) with good interobserver agreement (κ = 0.647). No difference was found regarding diagnostic accuracy between the two groups (P > 0.05). The effective dose for group A was lower by 80% compared to group B (P < 0.001). CONCLUSIONS 70-kVp high-pitch CTPA with reduced contrast media and SAFIRE provides comparable image quality and substantial radiation dose savings compared to a routine CTPA protocol.
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Han BK, Rigsby CK, Leipsic J, Bardo D, Abbara S, Ghoshhajra B, Lesser JR, Raman SV, Crean AM, Nicol ED, Siegel MJ, Hlavacek A. Computed Tomography Imaging in Patients with Congenital Heart Disease, Part 2: Technical Recommendations. An Expert Consensus Document of the Society of Cardiovascular Computed Tomography (SCCT). J Cardiovasc Comput Tomogr 2015; 9:493-513. [DOI: 10.1016/j.jcct.2015.07.007] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 07/17/2015] [Indexed: 02/06/2023]
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Evaluation of A New Bolus Tracking–Based Algorithm for Predicting A Patient-Specific Time of Arterial Peak Enhancement in Computed Tomography Angiography. Invest Radiol 2015; 50:531-8. [DOI: 10.1097/rli.0000000000000160] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Seventy-Peak Kilovoltage High-Pitch Thoracic Aortic CT Angiography without ECG Gating: Evaluation of Image Quality and Radiation Dose. Acad Radiol 2015; 22:890-7. [PMID: 25872860 DOI: 10.1016/j.acra.2015.03.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 03/02/2015] [Accepted: 03/04/2015] [Indexed: 02/07/2023]
Abstract
RATIONALE AND OBJECTIVES To assess the feasibility of 70-kVp high-pitch non-ECG-gated thoracic aortic computed tomography angiography (CTA) with 40-mL contrast agent compared to 100-kVp standard-pitch CTA with 60-mL contrast agent. MATERIALS AND METHODS Sixty-seven patients (51 men and 16 women; mean age, 55 ± 14 years) received non-ECG-gated aortic CTA at 70 kVp, high pitch of 3.4, and 40-mL contrast agent (group A, n = 31) or CTA at 100-kVp, pitch of 1.2, and 60-mL contrast agent (group B, n = 36). Iterative reconstruction was used in all patients. For image quality assessment, CTA images were evaluated on a three-point scale and signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated and compared. Furthermore, computed tomography (CT) dose index was recorded. RESULTS Mean CT values and noise levels were higher in group A compared to group B (all P < .001), whereas SNR and CNR were lower than those in group B (all P < .001). Furthermore, the image quality of the aorta at the level of the diaphragm was lower in group A than that in group B (P < .05). However, image quality was graded as diagnostic in all patients, and motion artifacts of the aortic arch were significantly decreased in group A (P <.05). Interreader agreement was good or excellent for image quality assessment (k = 0.625-0.835). The 70-kVp CTA protocol, which allows dose reduction of 85%, was considered diagnostic in all instances by two readers. CONCLUSIONS Our proposed thoracic aortic CTA protocol provides diagnostic information with substantial reduction of both radiation and contrast agent doses compared to standard-pitch CTA at 100 kVp.
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