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Feasibility of Low Volume of High-Concentration Iodinated Contrast Medium With 70 kVp Tube Voltage on High-Pitch Dual-Source Computed Tomography Angiography in Children With Congenital Heart Disease. J Comput Assist Tomogr 2021; 45:52-58. [PMID: 32740051 DOI: 10.1097/rct.0000000000001033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The objective of this study was to investigate the feasibility of high-concentration iodinated contrast medium (CM) with 70 kVp tube voltage on high-pitch dual-source computed tomography (DSCT) in children with congenital heart disease (CHD). METHODS Fifty-eight CHD patients underwent high-pitch DSCT in 2 protocols: 70 kVp tube voltage, 1.0 mL/kg CM volume, 370 mg I/mL concentration (group A); 80 kVp tube voltage, 1.5 mL/kg CM volume, 350 mg I/mL concentration (group B). The diagnostic accuracy, image quality, iodine delivery rate, iodine dose, and radiation dose were compared. RESULTS There was no significant difference in the diagnostic accuracy (P > 0.05), image quality (P > 0.05) and iodine delivery rate (P > 0.05) between the 2 groups. The iodine dose (P < 0.05) and radiation dose (P < 0.05) in group A were significantly lower than those in group B. CONCLUSIONS Reduction in iodine dose and radiation exposure can be achieved with 70 kVp high-pitch DSCT by administering a smaller volume of high-concentration CM in children with CHD.
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Chest CTA in children younger than two years - a retrospective comparison of three contrast injection protocols. Sci Rep 2019; 9:18109. [PMID: 31792291 PMCID: PMC6889233 DOI: 10.1038/s41598-019-54498-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 11/14/2019] [Indexed: 12/26/2022] Open
Abstract
To obtain the highest diagnostic information with least side effects when performing thoracic CT angiography (CTA) is challenging in young children. The current study aims to compare three contrast agent (CA) injection protocols regarding image quality and CA characteristic: a standard CTA, a fixed-bolus delay protocol, and the “microbolus technique (MBT)” developed in our institution. Seventy chest CTA scans of patients (<2 years) were divided into three groups. MBT was applied in group I, the standard protocol in group II and a fixed bolus delay in group III. Objective image quality was assessed by measuring peak enhancement, image noise, signal-to-noise (SNR) and contrast-to-noise ratios (CNR). Two observers scored subjective image quality and artifacts. Significantly lower amounts of CA (mean ± SD) were used in the MBT group compared to Group II (9.0 ± 3.7 ml vs. 12.9 ± 4.5 ml). A lower, but still diagnostic (>400 HU) enhancement was registered in all major thoracic vessels in group I without significant differences regarding SNR and CNR in most regions (p < 0.05). The best scores for image quality and artifacts were reached in group I. All three chest CTA contrast injection protocols offered diagnostic vessel enhancement in young patients. MBT was associated with reduced image artifacts and less injected CA.
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You SK, Choi YH, Cheon JE, Kim WS, Kim IO, Lee SM, Cho HH. Effect of low tube voltage and low iodine concentration abdominal CT on image quality and radiation dose in children: preliminary study. Abdom Radiol (NY) 2019; 44:1928-1935. [PMID: 30683980 DOI: 10.1007/s00261-019-01896-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE To evaluate the image quality of a double-low protocol (low tube voltage and low iodine concentration) for abdominal CT in children. MATERIALS AND METHODS The double-low protocol was compared to the conventional protocol in pediatric patients weighing less than 40 kg from May 2016 to December 2016. Double-low protocol (Group A, n = 18): tube voltage, 70 kVp; and iodine concentration,: 250 mgI/mL versus Conventional protocol (Group B, n = 13): tube voltage, 80-100 kVp; and iodine concentration, 350 mgI/mL. Mean attenuation, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were compared between the two groups. Image contrast, noise, beam-hardening artifacts, and overall image quality were subjectively scored. Reader performance for correctly differentiating two groups by visual assessment was evaluated. Radiation dose and total iodine load were recorded. RESULTS The mean attenuations of the portal vein and liver and the mean image noise in Group A were higher than in Group B (p = 0.04, 0.03, 0.004, respectively). The mean SNR and CNR of the main portal vein and liver were lower in Group A without any statistically significant difference. There were no statistically significant differences between the two groups in qualitative analysis (image contrast, image noise, and overall image quality) with substantial agreement between the reviewers (weighted kappa values; 0.59-0.76). Significantly diminished radiation dose and iodine load were observed in Group A compared with Group B (25.0%, 36.8% reduction; p = 0.007, 0.006, respectively). CONCLUSION The double-low protocol was feasible for pediatric abdominal CT and reduced both radiation dose and iodine load, while maintaining image quality.
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Masuda T, Funama Y, Kiguchi M, Imada N, Oku T, Sato T, Awai K. Radiation dose reduction based on CNR index with low-tube voltage scan for pediatric CT scan: experimental study using anthropomorphic phantoms. SPRINGERPLUS 2016; 5:2064. [PMID: 27995041 PMCID: PMC5133217 DOI: 10.1186/s40064-016-3715-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 11/21/2016] [Indexed: 12/13/2022]
Abstract
Background To figure out the relationship between image noise and contrast noise ratio (CNR) at different tube voltages, using anthropomorphic new-born and 1-year-old phantoms, and to discuss the feasibility of radiation dose reduction, based on the obtained CNR index from image noise. We performed helical scans of the anthropomorphic new-born and 1-year-old phantoms. The CT numbers of the simulated aorta and image noise of the simulated mediastinum were measured; then CNR was calculated on 80, 100, and 120-kVp images reconstructed with filtered back projection (FBP) and iterative reconstruction (IR). We also measured the center and surface dose in the case of CNR of 14 using radio-photoluminescence glass dosimeters. Results The CT number of the simulated aorta was increased with decreasing tube voltage from 120 to 80 kVp (362.5–535.1 HU for the new-born, 358.9–532.6 HU for the 1-year-old). At CNR of 14, the center dose was 0.4, 0.6 and 0.9 mGy at FBP and 0.5, 0.6 and 0.9 mGy at IR and with the new-born phantom acquired at 80, 100 and 120 kVp, respectively. The center dose for FBP image was reduced by 56% at 80 kVp, 34% at 100 kVp for the new-born and 36% at 80 kVp, 22% at 100 kVp for the 1-year-old compared with that at 120 kVp. We obtained a relationship between image noise and CNR at different tube voltages using the anthropomorphic new-born and 1-year-old phantoms. Conclusion The use of index of CNR with low-tube voltage may achieve further radiation dose reduction in pediatric CT examination.
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Affiliation(s)
- Takanori Masuda
- Department of Radiological Technology, Tsuchiya General Hospital, Nakajima-cho 3-30, Naka-ku, Hiroshima, 730-8655 Japan ; Department of Diagnostic Radiology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
| | - Yoshinori Funama
- Department of Medical Physics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Masao Kiguchi
- Department of Diagnostic Radiology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
| | - Naoyuki Imada
- Department of Radiological Technology, Tsuchiya General Hospital, Nakajima-cho 3-30, Naka-ku, Hiroshima, 730-8655 Japan
| | - Takayuki Oku
- Department of Radiological Technology, Tsuchiya General Hospital, Nakajima-cho 3-30, Naka-ku, Hiroshima, 730-8655 Japan
| | - Tomoyasu Sato
- Department of Diagnostic Radiology, Tsuchiya General Hospital, Nakajima-cho 3-30, Naka-ku, Hiroshima, 730-8655 Japan
| | - Kazuo Awai
- Department of Diagnostic Radiology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
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Koh H, Ong CC, Choo YS, Liang CR, Tan GHZ, Lim TCW, Quek SC, Sriram S, Teo LLS. Radiation Dose and Image Quality in Pediatric Cardiac Computed Tomography: A Comparison Between Sequential and Third-Generation Dual-Source High-Pitch Spiral Techniques. Pediatr Cardiol 2016; 37:1397-1403. [PMID: 27377528 DOI: 10.1007/s00246-016-1447-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 06/23/2016] [Indexed: 10/21/2022]
Abstract
The aim of this study was to investigate whether there is a reduction in radiation dose and improvement in image quality of pediatric cardiac computed tomography scans performed using the high-pitch spiral technique on a new third-generation dual-source 2 × 192-slice scanner (group B) compared with scans performed using the sequential technique on a single-source 256-slice scanner (group A). We performed a retrospective observational study on 40 patients aged ≤18 years who underwent prospectively electrocardiogram-triggered cardiac computed tomography. Image quality was assessed by pre-defined objective indices and a four-point subjective score. Apart from a higher mean heart rate in group A (P = 0.016), there were otherwise no significant inter-group differences in patient characteristics. The median effective dose was 4.41 mSv (interquartile range 2.58-5.90 mSv) in group A and 0.52 mSv (interquartile range 0.39-0.59 mSv) in group B (P < 0.001), representing a 88 % reduction. Subjective image quality score was significantly better in group B (4 = excellent with no artifact, mode 57.1 %) than in group A (3 = good with mild artifact, mode 57.9 %) (P < 0.001). Noise index, signal-to-noise ratio and contrast-to-noise ratio between both groups were not statistically significant. New third-generation dual-source high-pitch spiral scan technique can deliver excellent image quality with low radiation dose. Our results suggest that it should be considered as a first-choice technique for performing cardiac computed tomography in the pediatric population.
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Affiliation(s)
- Huiliang Koh
- Department of Diagnostic Imaging, National University Hospital, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
| | - Ching Ching Ong
- Department of Diagnostic Imaging, National University Hospital, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
| | - Yun Song Choo
- Department of Diagnostic Imaging, National University Hospital, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
| | - Chong Ri Liang
- Department of Diagnostic Imaging, National University Hospital, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
| | - Grace Hui Zhen Tan
- Department of Diagnostic Imaging, National University Hospital, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
| | - Terence Chee Wen Lim
- Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
| | - Swee Chye Quek
- Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
| | - Shankar Sriram
- Department of Cardiac, Thoracic and Vascular Surgery, National University Heart Centre, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore
| | - Lynette Li San Teo
- Department of Diagnostic Imaging, National University Hospital, 5 Lower Kent Ridge Road, Singapore, 119074, Singapore.
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Effects of Dual-Energy Technique on Radiation Exposure and Image Quality in Pediatric Body CT. AJR Am J Roentgenol 2016; 207:826-835. [DOI: 10.2214/ajr.15.15994] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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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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Image quality, radiation dose and diagnostic accuracy of 70 kVp whole brain volumetric CT perfusion imaging: a preliminary study. Eur Radiol 2016; 26:4184-4193. [DOI: 10.1007/s00330-016-4225-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 01/02/2016] [Accepted: 01/15/2016] [Indexed: 11/30/2022]
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Halliburton SS, Rajiah P. Cardiac CT Scanner Technology: What Is New and What Is Next? CURRENT CARDIOVASCULAR IMAGING REPORTS 2016. [DOI: 10.1007/s12410-016-9370-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Booij R, Dijkshoorn ML, van Straten M, du Plessis FA, Budde RP, Moelker A, Krestin GP, Ouhlous M. Cardiovascular imaging in pediatric patients using dual source CT. J Cardiovasc Comput Tomogr 2016; 10:13-21. [DOI: 10.1016/j.jcct.2015.10.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 09/01/2015] [Accepted: 10/14/2015] [Indexed: 10/22/2022]
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Image quality and dose optimisation for infant CT using a paediatric phantom. Eur Radiol 2015; 26:1387-95. [DOI: 10.1007/s00330-015-3951-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 07/24/2015] [Accepted: 07/28/2015] [Indexed: 01/17/2023]
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