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Kiriki M, Koizumi M, Maeda K, Sakai T, Kotoura N. Development of the Split-Bolus Pulmonary Arteriovenous Separating Computed Tomography Angiography Protocol Based on Time Enhancement Curve for Lung Cancer Surgery. J Comput Assist Tomogr 2024:00004728-990000000-00322. [PMID: 38693071 DOI: 10.1097/rct.0000000000001621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
OBJECTIVE We devised a split-bolus injection and imaging protocol for pulmonary artery and vein separation computed tomography (CT) angiography based on time enhancement curve characterization. Furthermore, we aimed to evaluate the contrast enhancement effect and success rate of blood vessel separation between the pulmonary artery and vein of this proposed protocol. METHODS In this study, 102 patients (45 patients with the standard protocol and 57 patients with the proposed protocol) who underwent pulmonary arteriovenous computed tomography angiography were included. The CT values of various vessels, CT value difference between the pulmonary trunk and left atrium, and coefficient of variation in pulmonary arteries and veins were obtained from images of the standard and proposed protocols. RESULTS The CT values in the proposed protocol for the pulmonary trunk were significantly higher than those in the standard protocol (487.3 [415.5-546.9] HU vs. 293.0 [259.0-350.0] HU, P < 0.01). The CT value difference between the pulmonary trunk and left atrium in the proposed protocol was significantly higher than that in the conventional protocol (211.3 [158.0-265.7] HU vs. 32 [-30.0-55.0] HU, P < 0.01). The coefficient of variation in the proposed protocol was 0.08 (0.06-0.10) and 0.09 (0.08-0.11) in pulmonary arteries and 0.08 (0.06-0.09) and 0.09 (0.07-0.12) in pulmonary veins, respectively. CONCLUSIONS The proposed protocol achieved separation between the pulmonary artery and vein in many patients, making it useful for the preoperative assessment of individual thoracic anatomy.
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Affiliation(s)
- Masato Kiriki
- From the Department of Radiological Technology, Hyogo Medical University Hospital, Nishinomiya
| | - Masashi Koizumi
- From the Department of Radiological Technology, Hyogo Medical University Hospital, Nishinomiya
| | - Katsuhiko Maeda
- Department of Radiology, Ashiya Municipal Hospital, Ashiya, Japan
| | - Toshiyuki Sakai
- From the Department of Radiological Technology, Hyogo Medical University Hospital, Nishinomiya
| | - Noriko Kotoura
- From the Department of Radiological Technology, Hyogo Medical University Hospital, Nishinomiya
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Feldle P, Grunz JP, Kunz AS, Pannenbecker P, Patzer TS, Pichlmeier S, Sauer ST, Hendel R, Ergün S, Bley TA, Huflage H. Influence of spectral shaping and tube voltage modulation in ultralow-dose computed tomography of the abdomen. BMC Med Imaging 2024; 24:49. [PMID: 38395772 PMCID: PMC10893640 DOI: 10.1186/s12880-024-01228-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 02/14/2024] [Indexed: 02/25/2024] Open
Abstract
PURPOSE Unenhanced abdominal CT constitutes the diagnostic standard of care in suspected urolithiasis. Aiming to identify potential for radiation dose reduction in this frequent imaging task, this experimental study compares the effect of spectral shaping and tube voltage modulation on image quality. METHODS Using a third-generation dual-source CT, eight cadaveric specimens were scanned with varying tube voltage settings with and without tin filter application (Sn 150, Sn 100, 120, 100, and 80 kVp) at three dose levels (3 mGy: standard; 1 mGy: low; 0.5 mGy: ultralow). Image quality was assessed quantitatively by calculation of signal-to-noise ratios (SNR) for various tissues (spleen, kidney, trabecular bone, fat) and subjectively by three independent radiologists based on a seven-point rating scale (7 = excellent; 1 = very poor). RESULTS Irrespective of dose level, Sn 100 kVp resulted in the highest SNR of all tube voltage settings. In direct comparison to Sn 150 kVp, superior SNR was ascertained for spleen (p ≤ 0.004) and kidney tissue (p ≤ 0.009). In ultralow-dose scans, subjective image quality of Sn 100 kVp (median score 3; interquartile range 3-3) was higher compared with conventional imaging at 120 kVp (2; 2-2), 100 kVp (1; 1-2), and 80 kVp (1; 1-1) (all p < 0.001). Indicated by an intraclass correlation coefficient of 0.945 (95% confidence interval: 0.927-0.960), interrater reliability was excellent. CONCLUSIONS In abdominal CT with maximised dose reduction, tin prefiltration at 100 kVp allows for superior image quality over Sn 150 kVp and conventional imaging without spectral shaping.
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Affiliation(s)
- Philipp Feldle
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Jan-Peter Grunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Andreas Steven Kunz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Pauline Pannenbecker
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Theresa Sophie Patzer
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Svenja Pichlmeier
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Stephanie Tina Sauer
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Robin Hendel
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Süleyman Ergün
- Institute of Anatomy and Cell Biology, University of Würzburg, Koellikerstraße 6, 97070, Würzburg, Germany
| | - Thorsten Alexander Bley
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Henner Huflage
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Oberdürrbacher Straße 6, 97080, Würzburg, Germany.
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Sookpeng S, Martin CJ. Impact of iodinated contrast media concentration on image quality for dual-energy CT and single-energy CT with low tube voltage settings. Acta Radiol 2023; 64:1047-1055. [PMID: 35912446 DOI: 10.1177/02841851221107625] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Contrast-induced nephropathy (CIN) is an adverse reaction associated with the use of intravenous contrast media (CM). PURPOSE To investigate the impact of low tube voltage settings on single-energy computed tomography (SECT) and rapid kV switching dual-energy CT (DECT) with reduced concentrations of iodinated CM. MATERIAL AND METHODS A phantom containing four different concentrations of CM (original concentration CM, 20%, 40%, and 60% reductions) was scanned using SECT mode with varying tube voltages (70, 80, 100, and 120 kVp) and DECT mode through reconstructing monoenergetic energy (50 keV and 70 keV) images. ATCM system with different noise index (NI) settings were set, and the images were reconstructed using ASiR-V. Image quality were measured for individual phantom sizes and protocols and compared to a reference protocol for SECT of 120 kVp, NI = 18, threshold contrast enhancement ≥280 HU, and CNR ≥17. RESULTS Tube voltage settings of 70 kVp together with 40% reduction in the iodinated CM is suitable for small phantom size, those of 80 kVp and 20% reduction is suitable for the medium and large sizes. This allows radiation doses to be reduced by 12%-30%. Values of CNR and contrast for DECT are better than those for SECT with the same NI setting. CONCLUSION Diagnostic reference of image quality can be maintained by using SECT with lower tube voltage and DECT with reductions of iodinated CM concentration and radiation dose. Therefore, the NI setting can be increased when DECT is used to achieve a similar image quality.
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Affiliation(s)
- Supawitoo Sookpeng
- Department of Radiological Technology, Faculty of Allied Health Sciences, 59212Naresuan University, Phitsanulok, Thailand
| | - Colin J Martin
- Department of Clinical Physics and Bioengineering, University of Glasgow, Gartnavel Royal Hospital, Glasgow, UK
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Inoue A, Uemura R, Takaki K, Sonoda A, Ota S, Nitta N, Batsaikhan B, Takahashi H, Watanabe Y. Clinical impact of low tube voltage computed tomography during hepatic arteriography with low iodine to detect hepatocellular carcinoma before transarterial chemoembolization. Eur J Radiol 2022; 154:110420. [DOI: 10.1016/j.ejrad.2022.110420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 05/31/2022] [Accepted: 06/20/2022] [Indexed: 11/17/2022]
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Ananthakrishnan L, Kay FU, Zeikus EA, Chu ES, Chang J, Barr JD, Rofsky NM, Abbara S. What the Baby Formula and Medical Contrast Material Shortages Have in Common: Insights and Recommendations for Managing the Iodinated Contrast Media Shortage. Radiol Cardiothorac Imaging 2022; 4:e220101. [PMID: 35833167 PMCID: PMC9274312 DOI: 10.1148/ryct.220101] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 05/21/2022] [Accepted: 05/21/2022] [Indexed: 05/25/2023]
Abstract
The impact of supply chain and supply chain logistics, including personnel directly and indirectly related to the movement of supplies, has come to light in a variety of industries since the global COVID-19 pandemic. Acutely, the experience with baby formula and iodinated contrast material exposes key vulnerabilities to supply chains. The rather sudden diminished availability of iodinated contrast material has forced health care systems to engage in more judicious use of product through catalyzing the adoption of behaviors that had been recommended and deemed reasonable prior to the shortage. The authors describe efforts at a large, academic safety net county health system to conserve iodinated contrast media by optimizing contrast media use in the CT department and changing ordering patterns of referring providers. Special attention is given to opportunities to conserve contrast material in cardiothoracic imaging, including low kV and dual-energy CT techniques. A values-based leadership philosophy and collaboration with key stakeholders facilitate effective response to the critical shortage and rapid deployment of iodinated contrast media conservation strategies. Last, while the single-supplier model is efficient and cost-effective, its application to critically necessary services such as health care must be questioned considering disruptions related to the COVID-19 pandemic. Keywords: CT, Intravenous Contrast Agents, CT-Spectral Imaging (Dual Energy) ©RSNA, 2022.
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Vlahos I, Jacobsen MC, Godoy MC, Stefanidis K, Layman RR. Dual-energy CT in pulmonary vascular disease. Br J Radiol 2022; 95:20210699. [PMID: 34538091 PMCID: PMC8722250 DOI: 10.1259/bjr.20210699] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 09/01/2021] [Accepted: 09/06/2021] [Indexed: 01/03/2023] Open
Abstract
Dual-energy CT (DECT) imaging is a technique that extends the capabilities of CT beyond that of established densitometric evaluations. CT pulmonary angiography (CTPA) performed with dual-energy technique benefits from both the availability of low kVp CT data and also the concurrent ability to quantify iodine enhancement in the lung parenchyma. Parenchymal enhancement, presented as pulmonary perfused blood volume maps, may be considered as a surrogate of pulmonary perfusion. These distinct capabilities have led to new opportunities in the evaluation of pulmonary vascular diseases. Dual-energy CTPA offers the potential for improvements in pulmonary emboli detection, diagnostic confidence, and most notably severity stratification. Furthermore, the appreciated insights of pulmonary vascular physiology conferred by DECT have resulted in increased use for the assessment of pulmonary hypertension, with particular utility in the subset of patients with chronic thromboembolic pulmonary hypertension. With the increasing availability of dual energy-capable CT systems, dual energy CTPA is becoming a standard-of-care protocol for CTPA acquisition in acute PE. Furthermore, qualitative and quantitative pulmonary vascular DECT data heralds promise for the technique as a "one-stop shop" for diagnosis and surveillance assessment in patients with pulmonary hypertension. This review explores the current application, clinical value, and limitations of DECT imaging in acute and chronic pulmonary vascular conditions. It should be noted that certain manufacturers and investigators prefer alternative terms, such as spectral or multi-energy CT imaging. In this review, the term dual energy is utilised, although readers can consider these terms synonymous for purposes of the principles explained.
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Affiliation(s)
- Ioannis Vlahos
- Department of Thoracic Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Megan C Jacobsen
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Myrna C Godoy
- Department of Thoracic Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | | | - Rick R Layman
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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Fleury AS, Durand RE, Cahill AM, Zhu X, Meyers KE, Otero HJ. Validation of computed tomography angiography as a complementary test in the assessment of renal artery stenosis: a comparison with digital subtraction angiography. Pediatr Radiol 2021; 51:2507-2520. [PMID: 34374838 DOI: 10.1007/s00247-021-05145-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 05/27/2021] [Accepted: 06/28/2021] [Indexed: 12/15/2022]
Abstract
BACKGROUND Renal artery stenosis is an important cause of hypertension in children, accounting for 5-10% of cases. When suspected, noninvasive imaging options include ultrasound (US), computed tomography (CT) angiography and magnetic resonance (MR) angiography. However, digital subtraction angiography (DSA) remains the gold standard. OBJECTIVE To investigate the accuracy and inter-reader reliability of CT angiography in children with suspected renal artery stenosis. MATERIALS AND METHODS This is a retrospective study of patients suspected of having renal artery stenosis evaluated by both CT angiography and DSA between 2008 and 2019 at a tertiary pediatric hospital. Only children who underwent CT angiography within 6 months before DSA were included. CT angiography studies were individually reviewed by two pediatric radiologists, blinded to clinical data, other studies and each other's evaluation, to determine the presence of stenosis at the main renal artery and 2nd- and 3rd-order branches. The sensitivity, specificity and accuracy were calculated using DSA as the reference. The effective radiation dose for CT angiography and DSA was also calculated. Kappa statistics were used to assess inter-reader agreement. RESULTS Seventy-four renal units were evaluated (18 girls, 19 boys). The patients' median age was 8 years (range: 1-21 years). Overall, CT angiography was effective in detecting renal artery stenosis with a sensitivity of 85.7%, specificity of 91.5% and accuracy of 88.9%. There was moderate inter-reader agreement at the main renal artery level (k=0.73) and almost perfect inter-reader agreement at the 2nd/3rd order (k=0.98). However, the sensitivity at the 2nd- and 3rd-order level was lower (14.3%). CT angiography provided excellent negative predictive value for evaluating renal artery stenosis at the main renal artery level (90.1%) and at the 2nd- or 3rd-order branches (82.7%). The median effective dose of CT angiography studies was 2.2 mSv (range: 0.6-6.3) while the effective dose of DSA was 13.7 mSv. CONCLUSION CT angiography has high sensitivity and specificity at the main renal artery level with a lower radiation dose than previously assumed. Therefore, it can be used as a diagnostic tool in patients with low to medium risk of renal artery stenosis, and as a screening and treatment planning tool in patients at high risk.
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Affiliation(s)
- Anilawan S Fleury
- Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA, 19104, USA
| | - Rachelle E Durand
- Department of Radiology and Biomedical Imaging, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA
| | - Anne Marie Cahill
- Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA, 19104, USA
| | - Xiaowei Zhu
- Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA, 19104, USA
| | - Kevin E Meyers
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Hansel J Otero
- Department of Radiology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA, 19104, USA.
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Chen J, Niu Z, Zhan K, Tao X, Tian F, Ding J, Jin Z, Hu X. Evaluation of Modified Calcium Removal Algorithm in dual energy CT of Internal Carotid Artery. Eur J Radiol 2021; 145:109927. [PMID: 34773829 DOI: 10.1016/j.ejrad.2021.109927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 06/23/2021] [Accepted: 08/14/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the performance of a dual-energy (DE) calcium removal software based on a modified three-material decomposition algorithm in assessing the stenosis of the internal carotid artery (ICA) in comparison with mixed images using digital subtraction angiography (DSA) as the reference standard. METHODS Forty-six patients (38 men; 67±8 years old), including 154 calcified ICA segments C1-C2 (59), C3-C5 (63), C6 (24), and C7 (8), were recruited in this retrospective study. Mixed images and virtual non-calcium (VNCa) images using the modified dual-energy computed tomography (DECT) algorithm were reconstructed. The differences between VNCa and DSA images vs. mixed and DSA images of degree of stenosis were compared. The intraclass correlation coefficient (ICC) was used for assessing the agreement between VNCa, mixed images, and DSA. RESULTS The degree of stenosis differed significantly between mixed and DSA images in the C3-C5 (30%±17.9% vs. 23.0%±16.9%, p = 0.026) and C6 (38.3%±15.4% vs. 28.5%±13.3%, p = 0.023) segments. The stenosis of VNCa images showed no significant difference with DSA images in all segments (all p > 0.05). The ICCs between VNCa and DSA images (0.86-0.97) were higher than those between the mixed and DSA images (0.68-0.96) in all segments. CONCLUSION The performance of a modified three-material decomposition DECT algorithm for calcium removal in ICA stenosis evaluation, particularly for the C3-C5 and C6 ICA segments, was promising.
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Affiliation(s)
- Jiao Chen
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China
| | - Zhongfeng Niu
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China
| | - Kun Zhan
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China
| | - Xinwei Tao
- Siemens Healthineers China, No.399, West Haiyang Road, Shanghai, China
| | - Fengjuan Tian
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China
| | - Jing Ding
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China
| | - Zhexia Jin
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China
| | - Xiuhua Hu
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China.
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De La Vega JC, Esquinas PL, Gill JK, Jessa S, Gill B, Thakur Y, Saatchi K, Häfeli UO. Comparison of Rhenium and Iodine as Contrast Agents in X-Ray Imaging. CONTRAST MEDIA & MOLECULAR IMAGING 2021; 2021:1250360. [PMID: 34803544 PMCID: PMC8575601 DOI: 10.1155/2021/1250360] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/22/2021] [Accepted: 10/01/2021] [Indexed: 11/18/2022]
Abstract
Purpose The majority of X-ray contrast agents (XCA) are made with iodine, but iodine-based XCA (I-XCA) exhibit low contrast in high kVp X-rays due to iodine's low atomic number (Z = 53) and K-edge (33.1 keV). While rhenium is a transition metal with a high atomic number (Z = 75) and K-edge (71.7 keV), the utilization of rhenium-based XCA (Re-XCA) in X-ray imaging techniques has not been studied in depth. Our study had two objectives: (1) to compare both the image quality and the absorbed dose of I- and Re-XCA and (2) to prepare and image a rhenium-doped scaffold. Procedures. I- and Re-XCA were prepared and imaged from 50 to 120 kVp by Micro-computed tomography (µCT) and digital radiography and from 120 to 220 kVp by planar X-ray imaging. The scans were repeated using 0.1 to 1.6 mm thick copper filters to harden the X-ray beam. A rhenium-doped scaffold was prepared via electrospinning, used to coat catheters, and imaged at 90 kVp by µCT. Results I-XCA have a greater contrast-to-noise ratio (CNR) at 50 and 80 kVp, but Re-XCA have a greater CNR at >120 kVp. The difference in CNR is increased as the thickness of the copper filters is increased. For instance, the percent CNR improvement of rhenium over iodine is 14.2% with a 0.6 mm thick copper filter, but it is 59.1% with a 1.6 mm thick copper filter, as shown at 120 kVp by µCT. Upon coating them with a rhenium-doped scaffold, the catheters became radiopaque. Conclusions Using Monte Carlo simulations, we showed that it is possible to reduce the absorbed dose of high kVp X-rays while allowing the acquisition of high-quality images. Furthermore, radiopaque catheters have the potential of enhancing the contrast during catheterizations and helping physicians to place catheters inside patients more rapidly and precisely.
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Affiliation(s)
- José Carlos De La Vega
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Pedro Luis Esquinas
- Medical Imaging Research Group, Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jovan Kaur Gill
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Selin Jessa
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Bradford Gill
- Medical Physics Department, BC Cancer, Vancouver, British Columbia, Canada
| | - Yogesh Thakur
- Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
- Medical Imaging, Vancouver Coastal Health, Vancouver, British Columbia, Canada
| | - Katayoun Saatchi
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Urs O. Häfeli
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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Yamasaki Y, Kamitani T, Sagiyama K, Matsuura Y, Hida T, Nagata H. Model-based iterative reconstruction for 320-detector row CT angiography reduces radiation exposure in infants with complex congenital heart disease. ACTA ACUST UNITED AC 2021; 27:42-49. [PMID: 33290239 DOI: 10.5152/dir.2020.19633] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE We investigated the impact of model-based iterative reconstruction (MBIR) on 320-detector row computed tomography angiography (CTA) in infants with complex congenital heart disease (CHD). METHODS Seventy infants with complex CHD who underwent 320-detector row CTA (40 boys and 30 girls; age range, 0-22 months; median age, 60 days) were retrospectively evaluated. First, the images were reconstructed by filtered back projection (FBP), hybrid iterative reconstruction (HIR), or MBIR in 20 cases, and variables were compared among the three iterative reconstruction methods (IR test). Second, the variables were compared between 25 cases scanned using HIR and 25 cases scanned using MBIR, with a 20 standard deviation noise level for both. Attenuation values and contrast-to-noise ratios (CNRs) of the great vessels and heart chambers were calculated. Total dose-length products were recorded for all patients (radiation dose: RD test). RESULTS In the IR test, the mean CNR values were 4.8±1.3 for FBP, 6.9±1.4 for HIR, and 8.2±1.7 for MBIR (P < 0.0001). The best subjective image qualities in the great vessels and heart chambers were obtained with MBIR. In RD testing, no significant differences between HIR and MBIR in image quality (CNR: HIR, 8.4±2.4; MBIR, 8.3±2.4) were observed. The effective dose was significantly lower for MBIR than for HIR (0.7±0.2 vs. 1.1±0.3 mSv; P < 0.001). CONCLUSION The MBIR algorithm significantly improved image quality and decreased radiation exposure in 320-row CTA of infants with complex CHD, providing an alternative to FBP or HIR that is both safer and produces better results.
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Affiliation(s)
- Yuzo Yamasaki
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takeshi Kamitani
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Koji Sagiyama
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yuko Matsuura
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Tomoyuki Hida
- Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Hazumu Nagata
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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Johansen CB, Martinsen ACT, Enden TR, Svanteson M. The potential of iodinated contrast reduction in dual-energy CT thoracic angiography; an evaluation of image quality. Radiography (Lond) 2021; 28:2-7. [PMID: 34301491 DOI: 10.1016/j.radi.2021.07.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 07/02/2021] [Accepted: 07/05/2021] [Indexed: 10/20/2022]
Abstract
INTRODUCTION The purpose of this study was to compare a dual energy CT (DECT) protocol with 50% reduction of iodinated contrast to a single energy CT (SECT) protocol using standard contrast dose in imaging of the thoracic aorta. METHODS DECT with a 50% reduction in iodinated contrast was compared with SECT. For DECT, monoenergetic images at 50, 55, 60, 65, 68, 70, and 74 keV were reconstructed with adaptive statistical iterative reconstruction (ASiR-V) of 50% and 80%. Objective image quality parameters included intravascular attenuation (HU), image noise (SD), contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR). Two independent radiologists subjectively assessed the image quality for the 55 and 68 keV DECT reconstructions and SECT on a five-point Likert scale. RESULTS Across 14 patients, the intravascular attenuation at 50-55 keV was comparable to SECT (p > 0.05). The CNRs were significantly lower for DECT with ASIR-V 50% compared to SECT for all keV-values (p < 0.05 for all). For ASIR-V 80%, CNR was comparable to SECT at energies below 60 keV (p > 0.05). The subjective image quality was comparable between DECT and SECT independent of keV level. CONCLUSION This study indicates that a 50% reduction in iodinated contrast may result in adequate image quality using DECT with monoenergetic reconstructions at lower energy levels for the imaging of the thoracic aorta. The best image quality was obtained for ASiR-V 80% image reconstructions at 55 keV. IMPLICATIONS OF PRACTICE Dual energy CT with a reduction in iodinated contrast may result in adequate image quality in imaging of the thoracic aorta. However, increased radiation dose may limit the use to patients in which a reduction in fluid and iodinated contrast volume may outweigh this risk.
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Affiliation(s)
- C B Johansen
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Norway; Faculty of Health Science, Oslo Metropolitan University, Norway.
| | - A C T Martinsen
- Faculty of Health Science, Oslo Metropolitan University, Norway; Sunnaas Rehabilitation Hospital, Norway.
| | - T R Enden
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Norway.
| | - M Svanteson
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Norway; ImTECH, Department of Diagnostic Physics, Oslo University Hospital, Norway.
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12
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Wang T, Lei Y, Roper J, Ghavidel B, Beitler JJ, McDonald M, Curran WJ, Liu T, Yang X. Head and neck multi-organ segmentation on dual-energy CT using dual pyramid convolutional neural networks. Phys Med Biol 2021; 66:115008. [PMID: 33915524 DOI: 10.1088/1361-6560/abfce2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 04/29/2021] [Indexed: 11/11/2022]
Abstract
Organ delineation is crucial to diagnosis and therapy, while it is also labor-intensive and observer-dependent. Dual energy CT (DECT) provides additional image contrast than conventional single energy CT (SECT), which may facilitate automatic organ segmentation. This work aims to develop an automatic multi-organ segmentation approach using deep learning for head-and-neck region on DECT. We proposed a mask scoring regional convolutional neural network (R-CNN) where comprehensive features are firstly learnt from two independent pyramid networks and are then combined via deep attention strategy to highlight the informative ones extracted from both two channels of low and high energy CT. To perform multi-organ segmentation and avoid misclassification, a mask scoring subnetwork was integrated into the Mask R-CNN framework to build the correlation between the class of potential detected organ's region-of-interest (ROI) and the shape of that organ's segmentation within that ROI. We evaluated our model on DECT images from 127 head-and-neck cancer patients (66 training, 61 testing) with manual contours of 19 organs as training target and ground truth. For large- and mid-sized organs such as brain and parotid, the proposed method successfully achieved average Dice similarity coefficient (DSC) larger than 0.8. For small-sized organs with very low contrast such as chiasm, cochlea, lens and optic nerves, the DSCs ranged between around 0.5 and 0.8. With the proposed method, using DECT images outperforms using SECT in almost all 19 organs with statistical significance in DSC (p<0.05). Meanwhile, by using the DECT, the proposed method is also significantly superior to a recently developed FCN-based method in most of organs in terms of DSC and the 95th percentile Hausdorff distance. Quantitative results demonstrated the feasibility of the proposed method, the superiority of using DECT to SECT, and the advantage of the proposed R-CNN over FCN on the head-and-neck patient study. The proposed method has the potential to facilitate the current head-and-neck cancer radiation therapy workflow in treatment planning.
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Affiliation(s)
- Tonghe Wang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA 30322, United States of America
| | - Yang Lei
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA 30322, United States of America
| | - Justin Roper
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA 30322, United States of America
| | - Beth Ghavidel
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA 30322, United States of America
| | - Jonathan J Beitler
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA 30322, United States of America
| | - Mark McDonald
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA 30322, United States of America
| | - Walter J Curran
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA 30322, United States of America
| | - Tian Liu
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA 30322, United States of America
| | - Xiaofeng Yang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA 30322, United States of America
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Tsurusaki M, Sofue K, Hori M, Sasaki K, Ishii K, Murakami T, Kudo M. Dual-Energy Computed Tomography of the Liver: Uses in Clinical Practices and Applications. Diagnostics (Basel) 2021; 11:diagnostics11020161. [PMID: 33499201 PMCID: PMC7912647 DOI: 10.3390/diagnostics11020161] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/10/2021] [Accepted: 01/20/2021] [Indexed: 02/06/2023] Open
Abstract
Dual-energy computed tomography (DECT) is an imaging technique based on data acquisition at two different energy settings. Recent advances in CT have allowed data acquisitions and simultaneous analyses of X-rays at two energy levels, and have resulted in novel developments in the field of abdominal imaging. The use of low and high X-ray tube voltages in DECT provide fused images that improve the detection of liver tumors owing to the higher contrast-to-noise ratio (CNR) of the tumor compared with the liver. The use of contrast agents in CT scanning improves image quality by enhancing the CNR and signal-to-noise ratio while reducing beam-hardening artifacts. DECT can improve detection and characterization of hepatic abnormalities, including mass lesions. The technique can also be used for the diagnosis of steatosis and iron overload. This article reviews and illustrates the different applications of DECT in liver imaging.
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Affiliation(s)
- Masakatsu Tsurusaki
- Department of Radiology, Faculty of Medicine, Kindai University, Osakasayama 589-8511, Japan;
- Correspondence: ; Tel.: +81-72-366-0221 (ext. 3133); Fax: +81-72-367-1685
| | - Keitaro Sofue
- Department of Radiology, Graduate School of Medicine, Kobe University, Kobe 650-0017, Japan; (K.S.); (M.H.); (T.M.)
| | - Masatoshi Hori
- Department of Radiology, Graduate School of Medicine, Kobe University, Kobe 650-0017, Japan; (K.S.); (M.H.); (T.M.)
| | - Kosuke Sasaki
- CT Research Group, GE Healthcare Japan, Hino 191-8503, Japan;
| | - Kazunari Ishii
- Department of Radiology, Faculty of Medicine, Kindai University, Osakasayama 589-8511, Japan;
| | - Takamichi Murakami
- Department of Radiology, Graduate School of Medicine, Kobe University, Kobe 650-0017, Japan; (K.S.); (M.H.); (T.M.)
| | - Masatoshi Kudo
- Department of Gastroenterology and Hepatology, Kindai University, Faculty of Medicine, Osakasayama 589-8511, Japan;
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Utility of 70-kV single-energy CT in depicting the extent of breast cancer for preoperative planning. Breast Cancer Res Treat 2020; 184:817-823. [PMID: 32910319 DOI: 10.1007/s10549-020-05909-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 09/01/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To evaluate the detectability of breast cancer and visibility of the tumor extent using 70-kV single-energy contrast-enhanced (CE) breast computed tomography (70-kV CECT) compared with CE breast magnetic resonance imaging (CEMR). METHODS Between 2013 and 2015, 110 patients with 112 breast cancer lesions who underwent breast surgery after undergoing both 70-kV CECT and CEMR were enrolled. The major axis lengths of the breast lesion were measured and compared with the pathologically determined major axes. Agreement in the measured major axes was evaluated using the intra-class correlation coefficient (ICC). RESULTS Both 70-kV CECT and CEMR depicted all breast cancer lesions. The mean major axis was 3.0 (95% confidence interval [CI], 2.5-3.4) cm on CECT and 2.9 (2.6-3.3) cm on CEMR. The mean differences between the pathologically and radiologically measured major axes on 70-kV CECT and CEMR were 0.9 (0.7-1.1) and 1.0 (0.8-1.2) cm, respectively. The accuracy of the radiological major axes compared with the pathological major axes was 82.1% and 80.4% on CECT and CEMR, respectively (p = 0.81). The major axes on the two modalities demonstrated moderate agreement (ICC = 0.69, 95% CI 0.58-0.77). Pathologically and radiologically measured major axes on 70-kV CECT and CEMR demonstrated excellent agreement (ICC = 0.91, 95% CI 0.93-0.96). CONCLUSIONS Low-tube voltage (70-kV) CECT is the preferred modality to identify breast cancer lesions and tumor extent for preoperative planning because it has a similar diagnostic ability to CEMR and can be performed in the supine position.
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Iyer VR, Ehman EC, Khandelwal A, Wells ML, Lee YS, Weber NM, Johnson MP, Yu L, McCollough CH, Fletcher JG. Image quality in abdominal CT using an iodine contrast reduction algorithm employing patient size and weight and low kV CT technique. Acta Radiol 2020; 61:1186-1195. [PMID: 31986894 DOI: 10.1177/0284185119898655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Low tube potential-high tube current computed tomography (CT) imaging allows reduction in iodine-based contrast dose and may extend the benefit of routine contrast-enhanced CT exams to patients at risk of nephrotoxicity. PURPOSE To determine the ability of an iodine contrast reduction algorithm to maintain diagnostic image quality for contrast-enhanced abdominal CT. MATERIAL AND METHODS CT exams with iodine contrast reduction were prescribed for patients at risk for renal dysfunction. The iodine contrast reduction algorithm combines weight-based contrast volume reduction with patient width-based low tube potential selection and bolus-tracking. Control exams with routine iodine dose were selected based on weight, width, and scan protocol. Three radiologists evaluated image quality and diagnostic confidence using a 4-point scale (<2 acceptable). Another radiologist assessed contrast reduction indications and measured portal vein and liver contrast-to-noise ratios. RESULTS Forty-six contrast reduction algorithm and control exams were compared (mean creatinine 1.6 vs. 1.2 mg/dL, P ≤ 0.0001). Thirty-nine contrast reduction patients had an eGFR <60 mL/min/1.73m2 and 15 had single or transplanted kidney. Mean iodine contrast dose was lower in the contrast reduction group (20.9 vs. 39.4 g/mL, P < 0.0001). Diagnostic confidence was rated as acceptable in 95% (131/138) of contrast reduction and 100% of control exams (1.18-1.28 vs. 1.02-1.13, respectively; P > 0.06). Liver attenuation and contrast-to-noise ratio (CNR) were similar (P = 0.08), but portal vein attenuation and CNR were lower with contrast-reduction (mean 176 vs. 198 HU, P = 0.02; 13 vs. 16, P = 0.0002). CONCLUSION This size-based contrast reduction algorithm using low kV and bolus tracking reduced iodine contrast dose by 50%, while achieving acceptable image quality in 95% of exams.
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Affiliation(s)
- Veena R Iyer
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | - Eric C Ehman
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | | | | | - Yong S Lee
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | | | - Matthew P Johnson
- Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, USA
| | - Lifeng Yu
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
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Abstract
Computed tomography angiography (CTA) has become a mainstay for the imaging of vascular diseases, because of high accuracy, availability, and rapid turnaround time. High-quality CTA images can now be routinely obtained with high isotropic spatial resolution and temporal resolution. Advances in CTA have focused on improving the image quality, increasing the acquisition speed, eliminating artifacts, and reducing the doses of radiation and iodinated contrast media. Dual-energy computed tomography provides material composition capabilities that can be used for characterizing lesions, optimizing contrast, decreasing artifact, and reducing radiation dose. Deep learning techniques can be used for classification, segmentation, quantification, and image enhancement.
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Affiliation(s)
- Prabhakar Rajiah
- Department of Radiology, Mayo Clinic, 200 1st Street SW, Rochester, MN 55904, USA.
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Merter A, Karaeminogullari O, Shibayama M. Comparison of Radiation Exposure Among 3 Different Endoscopic Diskectomy Techniques for Lumbar Disk Herniation. World Neurosurg 2020; 139:e572-e579. [PMID: 32330613 DOI: 10.1016/j.wneu.2020.04.079] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Lumbar disk herniation can be successfully treated by lumbar endoscopic spinal procedures. However, one of the most important disadvantages of the endoscopic methods used is radiation exposure. There are multiple endoscopic spinal procedures and this study aims to compare unilateral biportal endoscopic diskectomy (UBED), percutaneous endoscopic lumbar diskectomy (PELD), and microendoscopic diskectomy (MED) methods in terms of radiation exposure. METHODS A total of 75 people were included in this prospective and multicenter study. The demographic characteristics, operating times (minutes), levels of surgery, lumbar disk herniation types, radiation exposures (dose area product [DAP]), and fluoroscopy times (seconds) of the groups were compared. RESULTS Mean DAP values were 1.39 Gy·cm2 in the UBED group, 2.46 Gy·cm2 in the PELD group, and 1.01 Gy·cm2 in the MED group. The UBED group had no statistically significant difference with the MED and PELD groups in terms of DAP (P = 0.281 and P = 0.058, respectively), whereas the PELD group had statistically significantly higher DAP values than the MED group (P = 0.016). The maximum mean duration of fluoroscopy usage time was 34.9 seconds in the PELD group, 19.3 seconds in the UBED group, and 4.6 seconds in the MED group. The differences between the groups were significant (P ≤ 0.001). CONCLUSIONS The more the level of invasiveness is reduced in spinal surgery, the greater the exposure to radiation. In this study, the groups are listed as PELD > UBED > MED according to the duration and level of radiation exposure.
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Affiliation(s)
- Abdullah Merter
- Department of Orthopedics, Spine Section, School of Medicine, Ibn-i Sina Hospital, Ankara University, Ankara, Turkey.
| | - Oguz Karaeminogullari
- Department of Orthopedics, Spine Section, Bayindir Sogutozu Hospital, Ankara, Turkey
| | - Motohide Shibayama
- Department of Orthopedics, Spine Section, Aichi Spine Hospital, Aichi Prefecture, Japan
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Horinouchi H, Sofue K, Nishii T, Maruyama K, Sasaki K, Gentsu T, Ueshima E, Okada T, Yamaguchi M, Sugimoto K, Murakami T. CT angiography with 15 mL contrast material injection on time-resolved imaging for endovascular abdominal aortic aneurysm repair. Eur J Radiol 2020; 126:108861. [PMID: 32179423 DOI: 10.1016/j.ejrad.2020.108861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/30/2019] [Accepted: 01/29/2020] [Indexed: 10/25/2022]
Abstract
PURPOSE To assess the utility of whole-aorta CT angiography (CTA) with 15 mL contrast material (CM) on time-resolved imaging for endovascular abdominal aortic repair (EVAR). METHODS Twenty-six patients with a high-risk of post-contrast acute kidney injury (PC-AKI) underwent CTA with 15 mL CM using temporal maximum intensity projection (tMIP-CTA) generated from time-resolved imaging. The aortoiliac CT values were measured. Two observers measured the arterial diameters in unenhanced CT and tMIP-CTA images, and image quality was evaluated on a 5-point scale. The presence of the accessory renal artery, inferior mesenteric artery (IMA) occlusion, and instructions for use (IFU) of EVAR were evaluated. RESULTS CT examinations were successfully performed, and no patients developed PC-AKI. The mean CT values of the whole aorta were 267.5 ± 51.4 HU, which gradually decreased according to the distal levels of the aorta. Bland-Altman analysis revealed excellent agreement for the external arterial diameter measurements between unenhanced CT and tMIP-CTA. Excellent interobserver agreement was achieved for the measurements of the external (ICCs, 0.910-0.992) and internal arterial diameters (ICCs, 0.895-0.993). Excellent or good overall image quality was achieved in 24 (92 %) patients. The presence of the accessory renal artery, IMA occlusion and the assessment of IFU were in 100 % agreement. Multivariate analysis revealed aortic volume as the most significant independent factor associated with strong aortic enhancement (p = 0.004). CONCLUSIONS Whole-aorta tMIP-CTA on time-resolved imaging is useful for maintaining contrast enhancement and image quality for EVAR planning, and can substantially reduce the amount of CM.
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Affiliation(s)
- Hiroki Horinouchi
- Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan; Department of Radiology, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Keitaro Sofue
- Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan; Center for Endovascular Center, Kobe University Hospital, Kobe, Japan.
| | - Tatsuya Nishii
- Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan; Department of Radiology, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Koji Maruyama
- Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Koji Sasaki
- Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tomoyuki Gentsu
- Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan; Center for Endovascular Center, Kobe University Hospital, Kobe, Japan
| | - Eisuke Ueshima
- Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Takuya Okada
- Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Masato Yamaguchi
- Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Koji Sugimoto
- Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan; Center for Endovascular Center, Kobe University Hospital, Kobe, Japan
| | - Takamichi Murakami
- Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan
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Kawashima H, Ichikawa K, Takata T, Nagata H, Hoshika M, Akagi N. Technical Note: Performance comparison of ultra‐high‐resolution scan modes of two clinical computed tomography systems. Med Phys 2019; 47:488-497. [DOI: 10.1002/mp.13949] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 11/20/2019] [Accepted: 11/29/2019] [Indexed: 01/21/2023] Open
Affiliation(s)
- Hiroki Kawashima
- Faculty of Health Sciences Institute of Medical, Pharmaceutical and Health Sciences Kanazawa University 5‐11‐80 Kodatsuno Kanazawa 920‐0942Japan
| | - Katsuhiro Ichikawa
- Faculty of Health Sciences Institute of Medical, Pharmaceutical and Health Sciences Kanazawa University 5‐11‐80 Kodatsuno Kanazawa 920‐0942Japan
| | - Tadanori Takata
- Radiology Division Kanazawa University Hospital 13‐1 Takara‐machi Kanazawa 920‐8641Japan
| | - Hiroji Nagata
- Section of Radiological Technology Department of Medical Technology Kanazawa Medical University Hospital Daigaku 1‐1 Uchinada Kahoku 920‐0293Japan
| | - Minori Hoshika
- Departments of Radiology Okayama University Hospital 2‐5‐1 Shikatacho Kitaku Okayama 700‐8558Japan
| | - Noriaki Akagi
- Departments of Radiology Okayama University Hospital 2‐5‐1 Shikatacho Kitaku Okayama 700‐8558Japan
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Kitano T, Kaneko M, Yamada S. [Utility of Split-bolus Single-phase Protocol for Pulmonary Artery and Vein Separation Preoperative 3D-CTA in Lung Cancer Video-assisted Thoracic Surgery]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2019; 75:1165-1172. [PMID: 31631110 DOI: 10.6009/jjrt.2019_jsrt_75.10.1165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
There are many variations in branching and running of pulmonary artery (PA) and pulmonary vein (PV). It is desirable to separate as a surgical simulation of lung cancer and important to grasp before video-assisted thoracic surgery (VATS) to perform quick and safe. Therefore, the purpose of this study was to evaluate objective and subjective image quality (contrast attenuation, separation ability, and vascular visualization) of PA and PV of splitbolus single-phase protocol (SBSPP) in preoperative three-dimensional computed tomography angiography (3DCTA). CT value of PA was 410.2±71.0 Hounsfield unit (HU), PV was 245.1±24.8 HU, difference between CT value of PA and CT value of PV was 164.5±60.9 HU. Subjective image quality of PA and PV could be visualized until more than the segmental branch level. SBSPP can obtain sufficient CT value for separate visualization of PA and PV, and before VATS useful PA and PV 3D-CTA imaging.
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Contrast Volume for Preoperative CT Angiography of the Aorta Based on Patient Heart Rate and Body Surface Area: A Pilot Study. J Belg Soc Radiol 2019; 103:57. [PMID: 31646268 PMCID: PMC6777198 DOI: 10.5334/jbsr.1714] [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] [Indexed: 11/20/2022] Open
Abstract
Purpose: To evaluate contrast agent dose reduction using an algorithm based on heart rate and body surface area. Methods: A prospective study with 55 patients undergoing aortic CT was performed. Contrast agent dose, enhancement and image quality between three study groups were compared. Group 1: a fixed, standard dose of 120 ml, group 2: contrast agent dose calculated based on heart rate and body surface area, group 3: additional dilution of 50% of the calculated dose based on heart rate and body surface area. Results: The mean contrast agent dose in group 2 was reduced by 15% (P < 0.01) with unchanged high visual scoring in comparison to group 1. In group 3, contrast agent dose reduction was 60% (P < 0.01); average image quality dropped 19% (P < 0.01) compared to group 1, but was still sufficient, except for two patients. Conclusions: Contrast agent dose was significantly reduced without compromising diagnostic efficacy using the proposed algorithm.
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Ultra-Low-Dose Neck CT With Low-Dose Contrast Material for Preoperative Staging of Thyroid Cancer: Image Quality and Diagnostic Performance. AJR Am J Roentgenol 2019; 212:748-754. [PMID: 30900916 DOI: 10.2214/ajr.18.20334] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Although CT has been used as a complementary diagnostic method for the preoperative diagnosis of thyroid cancer, it has the shortcomings of substantial radiation exposure and the use of contrast material (CM). The purpose of this article is to evaluate the image quality and diagnostic performance of 70-kVp thyroid CT with low volumes of CM versus conventional 120-kVp thyroid CT protocol. MATERIALS AND METHODS Eighty patients referred for preoperative thyroid CT were randomly divided into two groups (group A: 40 patients, 70 kVp, 60 mL of CM; group B: 40 patients, 120 kVp, 100 mL of CM). Quantitative and qualitative image quality and radiation doses for the two groups were compared using the Mann-Whitney U and chi-square tests. Degrees of agreement between preoperative CT staging and pathologic results were evaluated and compared using the Wald statistic. RESULTS Calculated signal-to-noise ratios of different anatomic structures, calculated contrast-to-noise ratios, overall image quality, subjective noise, and streak artifacts were not significantly different between the two groups (all p > 0.05), and neither were the accuracies of preoperative CT staging (all p > 0.05). The estimated effective doses were significantly lower in group A (mean [± SD], 0.52 ± 0.14 mSv in group A and 2.28 ± 0.29 mSv in group B; p < 0.001). CONCLUSION Ultra-low-dose 70-kVp CT with a low volume of CM provides sufficient image quality for preoperative staging of thyroid cancer and substantially reduces the radiation dose compared with standard 120-kVp CT.
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Lee J, Kim TH, Lee BK, Yoon YW, Kwon HM, Hong BK, Min PK, Choi EY, Oh CS, Park CH. Diagnostic accuracy of low-radiation coronary computed tomography angiography with low tube voltage and knowledge-based model reconstruction. Sci Rep 2019; 9:1308. [PMID: 30718631 PMCID: PMC6362232 DOI: 10.1038/s41598-018-37870-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/10/2018] [Indexed: 12/23/2022] Open
Abstract
We aimed to evaluate the accuracy of coronary computed tomography angiography (CCTA) with a low-radiation protocol and iterative model reconstruction (IMR), in comparison with invasive coronary angiography (ICA). Sixty-one patients (45 males; mean age, 61.9 ± 9.2 years) with suspected coronary artery disease who underwent CCTA and ICA were retrospectively enrolled. CCTA was performed with low tube voltage (80 or 100 kVp), low tube current (100–200 mAs), prospective ECG triggering, and IMR using a 64-slice computed tomography scanner. Coronary artery disease was defined as luminal narrowing of >50%, as assessed using CCTA and ICA. The sensitivity, specificity, positive (PPV) and negative (NPV) predictive value, and accuracy of CCTA were examined. The mean radiation dose of CCTA was 1.05 ± 0.36 mSv. No non-diagnostic segment was noted. The sensitivity, specificity, PPV, NPV, and accuracy of CCTA were 86.4%, 96.1%, 80.3%, 97.5%, and 94.6% on a per segment basis, 93.1%, 94.7%, 88.3%, 97.0%, and 94.2% on a per vessel basis, and 100%, 83.3%, 93.5%, 100%, and 95.1% on a per patient basis, respectively. In conclusion, a low-radiation CCTA protocol with IMR may be useful for diagnosing coronary artery disease, as it reduces the radiation dose while maintaining diagnostic accuracy.
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Affiliation(s)
- Joohee Lee
- Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Tae Hoon Kim
- Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Byoung Kwon Lee
- Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Young Won Yoon
- Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hyuck Moon Kwon
- Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Bum Kee Hong
- Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Pil-Ki Min
- Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Eui-Young Choi
- Division of Cardiology, Heart Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Chi Suk Oh
- Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Chul Hwan Park
- Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
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Talei Franzesi CR, Ippolito D, Riva L, Fior D, Cangiotti C, Sironi S. Diagnostic value of iterative reconstruction algorithm in low kV CT angiography (CTA) with low contrast medium volume for transcatheter aortic valve implantation (TAVI) planning: image quality and radiation dose exposure. Br J Radiol 2018; 91:20170802. [PMID: 30074831 PMCID: PMC6319841 DOI: 10.1259/bjr.20170802] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE: To evaluate image quality and radiation dose exposure of low-kV (100 kV) and low contrast medium (CM) volume CT angiography (CTA) in patients candidate to Transcatheter Aortic Valve Implantation (TAVI), in comparison with standard CTA protocol. METHODS: 79 patients candidate for TAVI were prospectively enrolled in this study and examined with 256-MDCT. 42 patients were evaluated using study-group protocol (100 kV; whole-body retrospective ECG-gating; with 50 ml of CM; iterative reconstruction algorithm) while 37 patients underwent a standard CTA study (120 kV; ECG-gating for chest; 100 ml of CM; FBP reconstruction). Overall image quality was evaluated using a 4-point scale. Vascular enhancement (HU) was then assessed in each patient by manually drawing multiple ROIs in lumen of 7 segments of the whole aorta. The radiation dose exposure of both groups was calculated and all data were compared and statistically analyzed. RESULTS: On low-kV protocol, higher mean attenuation values were achieved in all the measurements as compared to standard protocol. There were no significant differences in the image quality evaluation in both groups. Mean radiation dose value of study group was significantly lower than in control group (reduction of 20%). CONCLUSION: Low kV and low CM volume CTA protocols allow TAVI planning to be carried out with high quality images and a significant reduction in the radiation dose as compared to the standard CTA protocol. ADVANCES IN KNOWLEDGE: Low-kV CTA for pre-operative assessment of patients candidates for TAVI, permits to achieve a significant reduction of radiation dose exposure and contrast medium volume, reducing the risk of contrast induced nephropathy.
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Liu S, Sheng H, Shi H, Li W, Fan J, He J, Sun H. Computed tomography portography of patients with cirrhosis with normal body mass index: Comparison between low-tube-voltage CT with low contrast agent dose and conventional CT. Medicine (Baltimore) 2018; 97:e13141. [PMID: 30508890 PMCID: PMC6283149 DOI: 10.1097/md.0000000000013141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
This study is to investigate the computed tomography (CT) image quality of the low- tube-voltage protocol with low contrast agent dose.CT portography was performed in 118 cirrhosis patients with body mass index (BMI) less than 25 kg/m under 2 protocols: Protocol A, tube voltage of 90 kVp/395 mAs and contrast agent dosage of 1.2 mL/kg, and, Protocol B, tube voltage of 120 kVp/200 mAs and contrast agent dosage of 1.5 mL/kg.The number of patients in each protocol was 59. The CT value noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in portal veins was comparatively analyzed between the 2 protocols. The subjective image quality was further assessed on 5-point scales. Radiation dose was also recorded and statistical analysis was performed.The CT value, CNR, and SNR of the images were higher at 90 kVp than those at 120 kVp (P < .05). There was no significant difference in image noise between the 2 protocols (P > .05). The CT dose index volume, dose-length product, and effective dose at 90 kVp were 18.2%, 16.0%, and 16.0% less than that at 120 kVp, respectively. There was no difference in image quality score between the 2 protocols (P > .05). The average amount of contrast agent was decreased by 17.8% when the 90 kVp protocol was used.CT portography at 90 kVp combined with low-dosage contrast agent leads to a significant reduction in radiation dose and improved SNR and CNR, without deterioration of image quality.
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Affiliation(s)
- Sulan Liu
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University
| | - Huaqiang Sheng
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University
| | - Hao Shi
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University
| | - Wei Li
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University
| | - Jingli Fan
- Institute of Endemic Disease Prevention and Control of Shandong Province
| | - Jingzhen He
- Department of Radiology, Qilu Hospital Affiliated to Shandong University, Jinan, China
| | - Hongjun Sun
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University
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Masuda T, Funama Y, Nakaura T, Tahara M, Yamashita Y, Kiguchi M, Imada N, Sato T, Awai K. Radiation Dose Reduction with a Low-Tube Voltage Technique for Pediatric Chest Computed Tomographic Angiography Based on the Contrast-to-Noise Ratio Index. Can Assoc Radiol J 2018; 69:390-396. [DOI: 10.1016/j.carj.2018.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Revised: 03/08/2018] [Accepted: 05/16/2018] [Indexed: 10/28/2022] Open
Abstract
Introduction The aim of this study was to evaluate the radiation dose and image quality at low tube-voltage pediatric chest computed tomographic angiography (CTA) that applies the same contrast-to-noise ratio (CNR) index as the standard tube voltage technique. Materials and Methods Contrast-enhanced chest CTA scans of 100 infants were acquired on a 64-row multidetector computed tomography (MDCT) scanner. In the retrospective study, we evaluated 50 images acquired at 120 kVp; the image noise level was set at 25 Hounsfield units. In the prospective study, we used an 80-kVp protocol; the image noise level was 40 Hounsfield units because the iodine contrast was 1.6 times higher than on 120-kVp scans; the CNR was as in the 120-kVp protocol. We compared the CT number, image noise, CT dose index volume (CTDIvol), and the dose-length product on scans acquired with the 2 protocols. A diagnostic radiologist and a pediatric cardiologist visually evaluated all CTA images. Results The mean CTDIvol and the mean dose-length product were 0.5 mGy and 7.8 mGy-cm for 80- and 1.2 mGy and 20.8 mGy-cm for 120-kVp scans, respectively ( P < .001). The mean CTDIvol was 42% lower at 80 kVp than at 120 kVp, and there was no significant difference in the visual scores assigned to the CTA images ( P = .28). Conclusions With the CNR index being the same at 80-kVp and 120-kVp imaging, the radiation dose delivered to infants subjected to chest CTA can be reduced without degradation of the image quality.
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Affiliation(s)
- Takanori Masuda
- Department of Radiological Technology, Tsuchiya General Hospital, Hiroshima, 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
| | - Takeshi Nakaura
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Masahiro Tahara
- Department of Pediatric Cardiology, Tsuchiya General Hospital, Hiroshima, Japan
| | - Yukari Yamashita
- Department of Radiological Technology, Tsuchiya General Hospital, Hiroshima, 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, Hiroshima, Japan
| | - Tomoyasu Sato
- Department of Diagnostic Radiology, Tsuchiya General Hospital, Hiroshima, Japan
| | - Kazuo Awai
- Department of Diagnostic Radiology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan
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CT-angiography of the aorta in patients with Marfan disease - High-pitch MDCT at different levels of tube voltage combined with Sinogram Affirmed Iterative Reconstruction. Clin Imaging 2018; 51:123-132. [DOI: 10.1016/j.clinimag.2018.02.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 01/20/2018] [Accepted: 02/06/2018] [Indexed: 01/16/2023]
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Araki K, Yoshizako T, Yoshida R, Tada K, Kitagaki H. Low-voltage (80-kVp) abdominopelvic computed tomography allows 60% contrast dose reduction in patients at risk of contrast-induced nephropathy. Clin Imaging 2018; 51:352-355. [PMID: 29982133 DOI: 10.1016/j.clinimag.2018.05.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 05/16/2018] [Accepted: 05/31/2018] [Indexed: 01/29/2023]
Abstract
PURPOSE The purpose of this study was to evaluate the quality of image in abdominopelvic late phase computed tomography (CT) with a low tube voltage plus low dose contrast medium (CM) protocol (80-kVp, 60% CM). A compared with the conventional protocol (120-kVp, 100% CM) B in the same patients. MATERIAL AND METHODS This study included with 22 patients {36 to 77 kg (mean: 55.5 kg)} who had renal insufficiency and had experience of performance conventional CT without renal insufficiency during pre-18 months. The CT value of the portal vein, liver parenchyma, abdominal aorta, psoas muscle was measured. The estimated mean CNR (contrast-to-noise ratios), FOM (figure of merit), DLP (dose length product) and ED (effective dose) were compared between protocol A and B. Moreover, two radiologists assessed the visual quality of the CT images. RESULTS The mean DLP and ED in the protocol B was about 50% lower than that in the protocol A (p < 0.01). The mean CT value of the portal vein and abdominal aorta in the protocol B were significantly higher than that in the protocol A (p < 0.01). All of the FOM in the protocol B was significantly higher than that in the protocol A (p < 0.01). However, there was no significant difference in the mean CNR and visual quality between protocol A and B. CONCLUSION Performance of abdominopelvic CT using a low tube voltage plus reduced CM dose (80-kVp, 60% CM) achieved reduction of the radiation dose without impairing image quality in relatively light weight group. CLINICAL RELEVANCE/APPLICATION In abdominopelvic CT, protocol of low tube voltage (80-kVp) plus iodine dose reduction (60%) is able to provide the same quality of traditional protocols, also able to reducing radiation exposure (50%).
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Affiliation(s)
- Kazumi Araki
- Department of Radiology, Shimane University Faculty of Medicine, P.O. Box 00693-8501, 89-1 Enyacho, Izumo, Japan
| | - Takeshi Yoshizako
- Department of Radiology, Shimane University Faculty of Medicine, P.O. Box 00693-8501, 89-1 Enyacho, Izumo, Japan.
| | - Rika Yoshida
- Department of Radiology, Shimane University Faculty of Medicine, P.O. Box 00693-8501, 89-1 Enyacho, Izumo, Japan
| | - Keiji Tada
- Department of Radiology, Shimane University Hospital, P.O. Box 00693-8501, 89-1 Enyacho, Izumo, Japan
| | - Hajime Kitagaki
- Department of Radiology, Shimane University Faculty of Medicine, P.O. Box 00693-8501, 89-1 Enyacho, Izumo, Japan
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Hou P, Feng X, Liu J, Wang X, Jiang Y, Dong L, Gao J. Low Tube Voltage and Iterative Model Reconstruction in Follow-up CT Angiography After Thoracic Endovascular Aortic Repair: Ultra-low Radiation Exposure and Contrast Medium Dose. Acad Radiol 2018; 25:494-501. [PMID: 29249576 DOI: 10.1016/j.acra.2017.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 10/31/2017] [Accepted: 11/03/2017] [Indexed: 12/27/2022]
Abstract
RATIONALE AND OBJECTIVES This study aimed to investigate the feasibility of reducing radiation exposure and contrast medium (CM) dose in follow-up computed tomography angiography (CTA) after thoracic endovascular aortic repair (TEVAR) using low tube voltage and knowledge-based iterative model reconstruction (IMR). MATERIALS AND METHODS Thirty-six patients that required follow-up CTA after TEVAR were included in this intra-individual study. The conventional protocol with standard tube voltage of 120 kVp and CM volume of 70 mL was applied in the first follow-up CTA of all the patients (control group A). The ultra-low CM dose protocol with low tube voltage of 80 kVp and weight-adapted CM volume of 0.4 mL/kg was utilized in the second follow-up CTA (study group B). Set A.FBP (group A filtered back-projection) contained images for group A that were reconstructed through FBP method. Three sets (B.FBP, B.HIR, and B.IMR) for group B were reconstructed using three methods, FBP, hybrid iterative reconstruction (HIR), and IMR, respectively. Objective measurements including aortic attenuations, image noise, contrast-to-noise ratios (CNRs), and figure of merit of CNR (FOMCNR), and subjective rating scores of the four image sets were compared. RESULTS Compared to the images in set A.FBP, the images in set B.IMR had better quality in terms of equivalent attenuation values, equivalent subjective scores, lower noise, higher or equivalent CNRs, and higher FOMCNR. The quality of images in sets B.FBP and B.HIR was unacceptable. The radiation exposure and CM dose in group B were 1.94 mGy and 28 ± 5 mL, respectively, representing reductions of 77.6% (P < .001) and 60% (P < .001) as compared to those in group A. CONCLUSIONS In follow-up examinations after TEVAR, CTA with ultra-low radiation exposure and CM dose is feasible using low tube voltage and IMR for nonobese patients.
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Affiliation(s)
- Ping Hou
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, East Jianshe Road, Zhengzhou, Henan Province 450052, China
| | - Xiangnan Feng
- School of Economics and Management, Southwest Jiaotong University, Chengdu, China
| | - Jie Liu
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, East Jianshe Road, Zhengzhou, Henan Province 450052, China
| | - Xiaopeng Wang
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, East Jianshe Road, Zhengzhou, Henan Province 450052, China
| | - Yaojun Jiang
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, East Jianshe Road, Zhengzhou, Henan Province 450052, China
| | - Leigang Dong
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, East Jianshe Road, Zhengzhou, Henan Province 450052, China
| | - Jianbo Gao
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, East Jianshe Road, Zhengzhou, Henan Province 450052, China.
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Taguchi N, Oda S, Nakaura T, Utsunomiya D, Funama Y, Imuta M, Yuki H, Nagayama Y, Kidoh M, Hirata K, Iyama Y, Namimoto T, Kai N, Hatemura M, Yamashita Y. Contrast enhancement in abdominal computed tomography: influence of photon energy of different scanners. Br J Radiol 2017; 91:20170285. [PMID: 29076752 DOI: 10.1259/bjr.20170285] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE Different CT scanners have different X-ray spectra and photon energies indicating that contrast enhancement vary among scanners. However, this issue has not been fully validated; therefore, we performed phantom and clinical studies to assess this difference. METHODS Two scanners were used: scanner-A and scanner-B. In the phantom study, we compared the contrast enhancement between the scanners at tube voltage peaks of 80, 100 and 120 kVp. Then, we calculated the effective energies of the two CT scanners. In the clinical study, 40 patients underwent abdominal scanning with scanner-A and another 40 patients with scanner-B, with each group using the same scanning protocol. The contrast enhancement of abdominal organs was assessed quantitatively (based on the absolute difference between the attenuation of unenhanced scans and contrast-enhanced scans) and qualitatively. A two-tailed independent Student's t-test and or the Mann-Whitney U test were used to compare the discrepancies. RESULTS In the phantom study, contrast enhancement for scanner-B was 36.9, 32.6 and 30.8% higher than that for scanner-A at 80, 100 and 120 kVp, respectively. The effective energies were higher for scanner-A than for scanner-B. In the quantitative analysis for the clinical study, scanner-B yielded significantly better contrast enhancement of the hepatic parenchyma, pancreas, kidney, portal vein and inferior vena cava compared with that of scanner-A. The mean visual scores for contrast enhancement were also significantly higher on images obtained by scanner-B than those by scanner-A. CONCLUSION There were significant differences in contrast enhancement of the abdominal organs between the compared CT scanners from two different vendors even at the same scanning and contrast parameters. Advances in knowledge: Awareness of the impact of different X-ray energies on the resultant attenuation of contrast material is important when interpreting clinical CT images.
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Affiliation(s)
- Narumi Taguchi
- 1 Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University , Kumamoto , Japan
| | - Seitaro Oda
- 1 Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University , Kumamoto , Japan
| | - Takeshi Nakaura
- 1 Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University , Kumamoto , Japan
| | - Daisuke Utsunomiya
- 1 Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University , Kumamoto , Japan
| | - Yoshinori Funama
- 2 Department of Medical Physics, Faculty of Life Sciences, Kumamoto University , Kumamoto , Japan
| | - Masanori Imuta
- 1 Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University , Kumamoto , Japan
| | - Hideaki Yuki
- 1 Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University , Kumamoto , Japan
| | - Yasunori Nagayama
- 1 Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University , Kumamoto , Japan
| | - Masafumi Kidoh
- 1 Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University , Kumamoto , Japan
| | - Kenichiro Hirata
- 1 Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University , Kumamoto , Japan
| | - Yuji Iyama
- 1 Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University , Kumamoto , Japan
| | - Tomohiro Namimoto
- 1 Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University , Kumamoto , Japan
| | - Noriyuki Kai
- 3 Department of Central Radiology, Kumamoto University Hospital , Kumamoto , Japan
| | - Masahiro Hatemura
- 3 Department of Central Radiology, Kumamoto University Hospital , Kumamoto , Japan
| | - Yasuyuki Yamashita
- 1 Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University , Kumamoto , Japan
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Zhu Y, Li Z, Ma J, Hong Y, Pi Z, Qu X, Xu M, Li J, Zhou H. Imaging the Infant Chest without Sedation: Feasibility of Using Single Axial Rotation with 16-cm Wide-Detector CT. Radiology 2017; 286:279-285. [PMID: 28956735 DOI: 10.1148/radiol.2017170019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Purpose To compare image quality, patient preparation time, and radiation dose using a single axial rotation with 16-cm wide-detector computed tomography (CT) in imaging the infant chest without sedation with those in infants examined by using a 64-row CT and sedation. Materials and Methods Thirty-two infants (group 1) were prospectively enrolled to undergo nonenhanced chest CT without sedation using a single axial rotation on a 16-cm wide-detector CT scanner. Patients were imaged with automatic tube current modulation and tube voltages of 80 kVp for patients weighing 5 kg or less and 100 kVp for patients weighing more than 5 kg. Patient preparation time, CT dose index (CTDI), dose-length product (DLP), and image quality were compared with those in a historical control group consisting of 30 infants (group 2) who underwent conventional helical scanning with sedation performed by using a 64-row volume CT scanner. The Student t test for independent samples was used to assess continuous variables. The Mann-Whitney rank test and the κ test were used to evaluate image quality. Results There was no statistically significant difference in body weight, age, mean CT attenuation value, image noise, and subjective image quality score between the two groups. However, compared with the group scanned by using a 64-row volume CT scanner (group 2), group 1 experienced significantly reduced scan time by 83% (0.35 second vs 2.01 seconds ± 0.21 [standard deviation]), preparation time by 57% (41.25 minutes ± 103.78 vs 96.5 minutes ± 151.77), CTDI by 42% (2.03 mGy ± 0.4 vs 3.52 mGy ± 0.03), and DLP by 52% (27.07 mGy·cm ± 6.97 vs 55.84 mGy·cm ± 6.46) (P < .05 for all). Conclusion Compared with conventional 64-row helical CT with sedation, use of a single axial rotation with 16-cm wide-detector CT in imaging the infant chest without sedation can reduce radiation dose, preparation time, and total scan time, while providing comparable image quality. © RSNA, 2017.
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Affiliation(s)
- Yanan Zhu
- From the Medical Imaging Centre (Y.Z., Z.L., J.M., Z.P., X.Q., M.X., H.Z.) and Department of Pediatrics (Y.H.), Ankang Central Hospital, Ankang 725000, China; and CT Laboratory, GE Healthcare China, Beijing, China (J.L.)
| | - Zhengjun Li
- From the Medical Imaging Centre (Y.Z., Z.L., J.M., Z.P., X.Q., M.X., H.Z.) and Department of Pediatrics (Y.H.), Ankang Central Hospital, Ankang 725000, China; and CT Laboratory, GE Healthcare China, Beijing, China (J.L.)
| | - Jiankang Ma
- From the Medical Imaging Centre (Y.Z., Z.L., J.M., Z.P., X.Q., M.X., H.Z.) and Department of Pediatrics (Y.H.), Ankang Central Hospital, Ankang 725000, China; and CT Laboratory, GE Healthcare China, Beijing, China (J.L.)
| | - Yucai Hong
- From the Medical Imaging Centre (Y.Z., Z.L., J.M., Z.P., X.Q., M.X., H.Z.) and Department of Pediatrics (Y.H.), Ankang Central Hospital, Ankang 725000, China; and CT Laboratory, GE Healthcare China, Beijing, China (J.L.)
| | - Zhian Pi
- From the Medical Imaging Centre (Y.Z., Z.L., J.M., Z.P., X.Q., M.X., H.Z.) and Department of Pediatrics (Y.H.), Ankang Central Hospital, Ankang 725000, China; and CT Laboratory, GE Healthcare China, Beijing, China (J.L.)
| | - Xianfeng Qu
- From the Medical Imaging Centre (Y.Z., Z.L., J.M., Z.P., X.Q., M.X., H.Z.) and Department of Pediatrics (Y.H.), Ankang Central Hospital, Ankang 725000, China; and CT Laboratory, GE Healthcare China, Beijing, China (J.L.)
| | - Mingxing Xu
- From the Medical Imaging Centre (Y.Z., Z.L., J.M., Z.P., X.Q., M.X., H.Z.) and Department of Pediatrics (Y.H.), Ankang Central Hospital, Ankang 725000, China; and CT Laboratory, GE Healthcare China, Beijing, China (J.L.)
| | - Jianying Li
- From the Medical Imaging Centre (Y.Z., Z.L., J.M., Z.P., X.Q., M.X., H.Z.) and Department of Pediatrics (Y.H.), Ankang Central Hospital, Ankang 725000, China; and CT Laboratory, GE Healthcare China, Beijing, China (J.L.)
| | - Heping Zhou
- From the Medical Imaging Centre (Y.Z., Z.L., J.M., Z.P., X.Q., M.X., H.Z.) and Department of Pediatrics (Y.H.), Ankang Central Hospital, Ankang 725000, China; and CT Laboratory, GE Healthcare China, Beijing, China (J.L.)
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Liu S, Li W, Shi H, Sheng H, Fan J, He J, Sun H. Low-Dose Scanning Technology Combined with Low-Concentration Contrast Material in Renal Computed Tomography Angiography (CTA): A Preliminary Study. Med Sci Monit 2017; 23:4351-4359. [PMID: 28888094 PMCID: PMC5602168 DOI: 10.12659/msm.902917] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background This study is to investigate the feasibility of low iodine concentration contrast material (CM) combined with low tube voltage and adaptive statistical iterative reconstruction (ASIR) in renal computed tomography angiography (CTA). Material/Methods A total of 136 patients were enrolled in this prospective trial, and randomly divided into two groups: group A (n=68) and group B (n=68). Group A received 120-kVp and iopromide (370 mg/mL) with filtered back projection (FBP) reconstruction, and group B received 100-kVp and iodixanol (270 mg/mL) with ASIR 40% (ASIR40). An equal iodine dose (300 mg/kg body weight) and the same iodine delivery rate (1,500 mg I/s) were given to all patients. Density, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured, and the image quality and visualization of renal arteries were scored. Dose-length product (DLP) and CT dose index volume (CTDIvol) were recorded, and effective doses (ED) were calculated. Results There was no significant difference in image noise between groups A and B (p>0.05). The vessel attenuation, SNR, and CNR were significantly higher in group B than group A (all p<0.05). The subjective image quality and visualization of renal artery branches were similar in these two groups (p>0.05). Compared with group A, the CTDIvol, DLP, and ED in group B were decreased by 38.58%, 37.24%, and 37.24%, respectively (p=0.000). Conclusions Compared with 120-kVp with FBP reconstruction, the protocol of 100-kVp with ASIRP40 reconstruction provided high-quality renal CTA results, which allowed for reduced iodine concentration and decreased radiation dose.
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Affiliation(s)
- Sulan Liu
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University, Jinan, Shandong, China (mainland)
| | - Wei Li
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University, Jinan, Shandong, China (mainland)
| | - Hao Shi
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University, Jinan, Shandong, China (mainland)
| | - Huaqiang Sheng
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University, Jinan, Shandong, China (mainland)
| | - Jingli Fan
- Institute of Endemic Disease Prevention and Control of Shandong Province, Jinan, Shandong, China (mainland)
| | - Jingzhen He
- Department of Medical Imaging, Qilu Hospital Affiliated to Shandong University Shandong University, Jinan, Shandong, China (mainland)
| | - Hongjun Sun
- Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University, Jinan, Shandong, China (mainland)
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Wang T, Gong Y, Shi Y, Hua R, Zhang Q. Feasibility of dual-low scheme combined with iterative reconstruction technique in acute cerebral infarction volume CT whole brain perfusion imaging. Exp Ther Med 2017; 14:163-168. [PMID: 28672909 PMCID: PMC5488643 DOI: 10.3892/etm.2017.4451] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 03/27/2017] [Indexed: 12/22/2022] Open
Abstract
The feasibility of application of low-concentration contrast agent and low tube voltage combined with iterative reconstruction in whole brain computed tomography perfusion (CTP) imaging of patients with acute cerebral infarction was investigated. Fifty-nine patients who underwent whole brain CTP examination and diagnosed with acute cerebral infarction from September 2014 to March 2016 were selected. Patients were randomly divided into groups A and B. There were 28 cases in group A [tube voltage, 100 kV; contrast agent, iohexol (350 mg I/ml), reconstructed by filtered back projection] and 31 cases in group B [tube voltage, 80 kV; contrast agent, iodixanol (270 mg I/ml), reconstructed by algebraic reconstruction technique]. The artery CT value, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), dose length product, effective dose (ED) of radiation and brain iodine intake of both groups were measured and statistically analyzed. Two physicians carried out kappa (κ) analysis on the consistency of image quality evaluation. The difference in subjective image quality evaluation between the groups was tested by χ2. The differences in CT value, SNR, CNR, CTP and CT angiography subjective image quality evaluation between both groups were not statistically significant (P>0.05); the diagnosis rate of the acute infarcts between the two groups was not significantly different; while the ED and iodine intake in group B (dual low-dose group) were lower than group A. In conclusion, combination of low tube voltage and iterative reconstruction technique, and application of low-concentration contrast agent (270 mg I/ml) in whole brain CTP examination reduced ED and iodine intake without compromising image quality, thereby reducing the risk of contrast-induced nephropathy.
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Affiliation(s)
- Tao Wang
- CT Room, Xuzhou Central Hospital, Xuzhou, Jiangsu 221009, P.R. China
| | - Yi Gong
- Department of Ultrasound, Xuzhou Central Hospital, Xuzhou, Jiangsu 221009, P.R. China
| | - Yibing Shi
- CT Room, Xuzhou Central Hospital, Xuzhou, Jiangsu 221009, P.R. China
| | - Rong Hua
- CT Room, Xuzhou Central Hospital, Xuzhou, Jiangsu 221009, P.R. China
| | - Qingshan Zhang
- Department of Neurology, Xuzhou Central Hospital, Xuzhou, Jiangsu 221009, P.R. China
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Yoshida M, Utsunomiya D, Kidoh M, Yuki H, Oda S, Shiraishi S, Yamamoto H, Inomata Y, Yamashita Y. CT evaluation of living liver donor: Can 100-kVp plus iterative reconstruction protocol provide accurate liver volume and vascular anatomy for liver transplantation with reduced radiation and contrast dose? Medicine (Baltimore) 2017; 96:e6973. [PMID: 28591031 PMCID: PMC5466209 DOI: 10.1097/md.0000000000006973] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We evaluated whether donor computed tomography (CT) with a combined technique of lower tube voltage and iterative reconstruction (IR) can provide sufficient preoperative information for liver transplantation.We retrospectively reviewed CT of 113 liver donor candidates. Dynamic contrast-enhanced CT of the liver was performed on the following protocol: protocol A (n = 70), 120-kVp with filtered back projection (FBP); protocol B (n = 43), 100-kVp with IR. To equalize the background covariates, one-to-one propensity-matched analysis was used. We visually compared the score of the hepatic artery (A-score), portal vein (P-score), and hepatic vein (V-score) of the 2 protocols and quantitatively correlated the graft volume obtained by CT volumetry (graft-CTv) under the 2 protocols with the actual graft weight.In total, 39 protocol-A and protocol-B candidates showed comparable preoperative clinical characteristics with propensity matching. For protocols A and B, the A-score was 3.87 ± 0.73 and 4.51 ± 0.56 (P < .01), the P-score was 4.92 ± 0.27 and 5.0 ± 0.0 (P = .07), and the V-score was 4.23 ± 0.78 and 4.82 ± 0.39 (P < .01), respectively. Correlations between the actual graft weight and graft-CTv of protocols A and B were 0.97 and 0.96, respectively.Liver-donor CT imaging under 100-kVp plus IR protocol provides better visualization for vascular structures than that under 120-kVp plus FBP protocol with comparable accuracy for graft-CTv, while lowering radiation exposure by more than 40% and reducing contrast-medium dose by 20%.
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Affiliation(s)
| | | | | | | | | | | | - Hidekazu Yamamoto
- Department of Pediatric and Transplant Surgery, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Yukihiro Inomata
- Department of Pediatric and Transplant Surgery, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
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Macía-Suárez D, Sánchez-Rodríguez E, Lopez-Calviño B, Diego C, Pombar M. Low-voltage chest CT: another way to reduce the radiation dose in asbestos-exposed patients. Clin Radiol 2017; 72:797.e1-797.e10. [PMID: 28478929 DOI: 10.1016/j.crad.2017.03.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 03/26/2017] [Accepted: 03/30/2017] [Indexed: 10/19/2022]
Abstract
AIM To assess whether low voltage chest computed tomography (CT) can be used to successfully diagnose disease in patients with asbestos exposure. MATERIALS AND METHODS Fifty-six former employees of the shipbuilding industry, who were candidates to receive a standard-dose chest CT due to their occupational exposure to asbestos, underwent a routine CT. Immediately after this initial CT, they underwent a second acquisition using low-dose chest CT parameters, based on a low potential (80 kV) and limited tube current. The findings of the two CT protocols were compared based on typical diseases associated with asbestos exposure. The kappa coefficient for each parameter and for an overall rating (grouping them based on mediastinal, pleural, and pulmonary findings) were calculated in order to test for correlations between the two protocols. RESULTS A good correlation between routine and low-dose CT was demonstrated for most parameters with a mean radiation dose reduction of up to 83% of the effective dose based on the dose-length product between protocols. CONCLUSIONS Low-dose chest CT, based on a limited tube potential, is useful for patients with an asbestos exposure background. Low-dose chest CT can be successfully used to minimise the radiation dose received by patients, as this protocol produced an estimated mean effective dose similar to that of an abdominal or pelvis plain film.
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Affiliation(s)
- D Macía-Suárez
- Complexo Hospitalario Universitario de Ferrol, Avda Residencia, s/n, CP: 15405, Ferrol (A Coruña), Spain.
| | - E Sánchez-Rodríguez
- Facultad de Biología, Campus universitario Lagoas, Marcosende, CP: 36200, Vigo, Spain
| | - B Lopez-Calviño
- Unidad de epidemiología clínica y estadística, Complejo Hospitalario Universitario A Coruña-INIBIC, As Xubias de Arriba, 84, CP: 15006, A Coruña, Spain
| | - C Diego
- Complexo Hospitalario Universitario de Ferrol, Avda Residencia, s/n, CP: 15405, Ferrol (A Coruña), Spain
| | - M Pombar
- Servizo de Radiofísica e Protección Radiolóxica, Complexo Hospitalario Universitario de Santiago de Compostela, Trav. Choupana, s/n, CP: 15706, Santiago de Compostela (Acoruña), Spain
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Tailored Duration of Contrast Material Injection in High-Pitch Computed Tomographic Aortography With a Double-Level Test Bolus Method. Invest Radiol 2017; 52:274-280. [DOI: 10.1097/rli.0000000000000340] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Qualitative and Quantitative Imaging Evaluation of Renal Cell Carcinoma Subtypes with Grating-based X-ray Phase-contrast CT. Sci Rep 2017; 7:45400. [PMID: 28361951 PMCID: PMC5374440 DOI: 10.1038/srep45400] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 02/21/2017] [Indexed: 11/13/2022] Open
Abstract
Current clinical imaging methods face limitations in the detection and correct characterization of different subtypes of renal cell carcinoma (RCC), while these are important for therapy and prognosis. The present study evaluates the potential of grating-based X-ray phase-contrast computed tomography (gbPC-CT) for visualization and characterization of human RCC subtypes. The imaging results for 23 ex vivo formalin-fixed human kidney specimens obtained with phase-contrast CT were compared to the results of the absorption-based CT (gbCT), clinical CT and a 3T MRI and validated using histology. Regions of interest were placed on each specimen for quantitative evaluation. Qualitative and quantitative gbPC-CT imaging could significantly discriminate between normal kidney cortex (54 ± 4 HUp) and clear cell (42 ± 10), papillary (43 ± 6) and chromophobe RCCs (39 ± 7), p < 0.05 respectively. The sensitivity for detection of tumor areas was 100%, 50% and 40% for gbPC-CT, gbCT and clinical CT, respectively. RCC architecture like fibrous strands, pseudocapsules, necrosis or hyalinization was depicted clearly in gbPC-CT and was not equally well visualized in gbCT, clinical CT and MRI. The results show that gbPC-CT enables improved discrimination of normal kidney parenchyma and tumorous tissues as well as different soft-tissue components of RCCs without the use of contrast media.
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Reducing Iodine Contrast Volume in CT Angiography of the Abdominal Aorta Using Integrated Tube Potential Selection and Weight-Based Method Without Compromising Image Quality. AJR Am J Roentgenol 2017; 208:552-563. [DOI: 10.2214/ajr.16.16613] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Computed Tomographic Angiography of the Abdomen and Pelvis in Azotemic Patients Utilizing 80-kV(p) Technique and Reduced Dose Iodinated Contrast. J Comput Assist Tomogr 2017; 41:141-147. [DOI: 10.1097/rct.0000000000000478] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Iyama Y, Nakaura T, Yokoyama K, Kidoh M, Yamashita Y. Cardiac helical CT involving a low-radiation-dose protocol with a 100-kVp setting: Usefulness of hybrid iterative reconstruction and display preset optimization. Medicine (Baltimore) 2016; 95:e5459. [PMID: 27861400 PMCID: PMC5120957 DOI: 10.1097/md.0000000000005459] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
To compare the radiation dose and image quality of retrospective electrocardiogram (ECG)-gated cardiac computed tomography (CT) between a 100-kVp protocol, hybrid iterative reconstruction (HIR), and display preset optimization and the 120-kVp protocol.We prospectively enrolled 100 patients with tachycardia or atrial fibrillation scanned retrospective ECG-gated cardiac CT. We randomly assigned 50 patients to the 120-kVp protocol and 50 patients to the 100-kVp protocol. We compared effective doses (EDs) between the two protocols. The 120-kVp images were post-processed using filtered back projection (FBP). The 100-kVp images were post-processed using FBP (100-kVp protocol) and HIR (i-100-kVp protocol). We compared attenuation of the ascending aorta, signal-to-noise ratio (SNR), and image noise between the 120-kVp, 100-kVp, and i-100-kVp protocols. We performed qualitative image analysis for the 120-kVp and i-100-kVp protocols.ED of the 100-kVp protocol (4.4 ± 0.4 mSv) was 76% lower than that of the 120-kVp protocol (18.4 ± 0.6 mSv). Attenuations of the 100-kVp (549.1 ± 73.8 HU) and i-100-kVp (550.5 ± 73.7 HU) protocols were higher than that of the120-kVp protocol (437.3 ± 55.7 HU). Image noise of the 100-kVp (53.6 ± 18.5 HU) and i-100-kVp (30.9 ± 8.6 HU) protocols were higher than that of the120-kVp protocol (23.8 ± 5.7 HU). There was no significant difference in SNR and the result of qualitative image analysis between the 120-kVp and i-100-kVp protocols.The 100-kVp protocol with HIR reduced the 76% radiation dose while preserving the image quality compared with the conventional 120-kVp protocol on retrospective ECG-gated cardiac CT.
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Affiliation(s)
- Yuji Iyama
- Diagnostic Radiology, Kumamoto chuo hospital
- Department of Diagnostic Radiology, Graduate School of Medical, Kumamoto University
| | - Takeshi Nakaura
- Department of Diagnostic Radiology, Graduate School of Medical, Kumamoto University
| | - Koichi Yokoyama
- Department of Diagnostic Radiology, Graduate School of Medical, Kumamoto University
- Diagnostic Radiology, Amakusa Medical Center, Amakusa, Kumamoto, Japan
| | - Masafumi Kidoh
- Department of Diagnostic Radiology, Graduate School of Medical, Kumamoto University
| | - Yasuyuki Yamashita
- Department of Diagnostic Radiology, Graduate School of Medical, Kumamoto University
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Murphy KP, McLaughlin PD, Twomey M, Chan VE, Moloney F, Fung AJ, Chan FE, Kao T, O'Neill SB, Watson B, O'Connor OJ, Maher MM. Accurate tissue characterization in low-dose CT imaging with pure iterative reconstruction. J Med Imaging Radiat Oncol 2016; 61:190-196. [PMID: 27739229 DOI: 10.1111/1754-9485.12546] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 09/09/2016] [Indexed: 11/28/2022]
Abstract
INTRODUCTION We assess the ability of low-dose hybrid iterative reconstruction (IR) and 'pure' model-based IR (MBIR) images to maintain accurate Hounsfield unit (HU)-determined tissue characterization. METHODS Standard-protocol (SP) and low-dose modified-protocol (MP) CTs were contemporaneously acquired in 34 Crohn's disease patients referred for CT. SP image reconstruction was via the manufacturer's recommendations (60% FBP, filtered back projection; 40% ASiR, Adaptive Statistical iterative Reconstruction; SP-ASiR40). MP data sets underwent four reconstructions (100% FBP; 40% ASiR; 70% ASiR; MBIR). Three observers measured tissue volumes using HU thresholds for fat, soft tissue and bone/contrast on each data set. Analysis was via SPSS. RESULTS Inter-observer agreement was strong for 1530 datapoints (rs > 0.9). MP-MBIR tissue volume measurement was superior to other MP reconstructions and closely correlated with the reference SP-ASiR40 images for all tissue types. MP-MBIR superiority was most marked for fat volume calculation - close SP-ASiR40 and MP-MBIR Bland-Altman plot correlation was seen with the lowest average difference (336 cm3 ) when compared with other MP reconstructions. CONCLUSIONS Hounsfield unit-determined tissue volume calculations from MP-MBIR images resulted in values comparable to SP-ASiR40 calculations and values that are superior to MP-ASiR images. Accuracy of estimation of volume of tissues (e.g. fat) using segmentation software on low-dose CT images appears optimal when reconstructed with pure IR.
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Affiliation(s)
- Kevin P Murphy
- Department of Radiology, University College Cork, Cork, Ireland
| | | | - Maria Twomey
- Department of Radiology, University College Cork, Cork, Ireland
| | - Vincent E Chan
- Department of Radiology, University College Cork, Cork, Ireland
| | - Fiachra Moloney
- Department of Radiology, University College Cork, Cork, Ireland
| | - Adrian J Fung
- Department of Radiology, University College Cork, Cork, Ireland
| | - Faimee E Chan
- Department of Radiology, University College Cork, Cork, Ireland
| | - Tafline Kao
- Department of Radiology, University College Cork, Cork, Ireland
| | | | - Benjamin Watson
- Department of Radiology, University College Cork, Cork, Ireland
| | - Owen J O'Connor
- Department of Radiology, University College Cork, Cork, Ireland
| | - Michael M Maher
- Department of Radiology, University College Cork, Cork, Ireland
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Optimizing CT technique to reduce radiation dose: effect of changes in kVp, iterative reconstruction, and noise index on dose and noise in a human cadaver. Radiol Phys Technol 2016; 10:180-188. [DOI: 10.1007/s12194-016-0382-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/21/2016] [Accepted: 09/25/2016] [Indexed: 10/20/2022]
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Coronary Computed Tomographic Angiography at 80 kVp and Knowledge-Based Iterative Model Reconstruction Is Non-Inferior to that at 100 kVp with Iterative Reconstruction. PLoS One 2016; 11:e0163410. [PMID: 27658197 PMCID: PMC5033462 DOI: 10.1371/journal.pone.0163410] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 09/08/2016] [Indexed: 11/19/2022] Open
Abstract
The aims of this study were to compare the image noise and quality of coronary computed tomographic angiography (CCTA) at 80 kVp with knowledge-based iterative model reconstruction (IMR) to those of CCTA at 100 kVp with hybrid iterative reconstruction (IR), and to evaluate the feasibility of a low-dose radiation protocol with IMR. Thirty subjects who underwent prospective electrocardiogram-gating CCTA at 80 kVp, 150 mAs, and IMR (Group A), and 30 subjects with 100 kVp, 150 mAs, and hybrid IR (Group B) were retrospectively enrolled after sample-size calculation. A BMI of less than 25 kg/m2 was required for inclusion. The attenuation value and image noise of CCTA were measured and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated at the proximal right coronary artery and left main coronary artery. The image noise was analyzed using a non-inferiority test. The CCTA images were qualitatively evaluated using a four-point scale. The radiation dose was significantly lower in Group A than Group B (0.69 ± 0.08 mSv vs. 1.39 ± 0.15 mSv, p < 0.001). The attenuation values were higher in Group A than Group B (p < 0.001). The SNR and CNR in Group A were higher than those of Group B. The image noise of Group A was non-inferior to that of Group B. Qualitative image quality of Group A was better than that of Group B (3.6 vs. 3.4, p = 0.017). CCTA at 80 kVp with IMR could reduce the radiation dose by about 50%, with non-inferior image noise and image quality than those of CCTA at 100 kVp with hybrid IR.
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Wu Q, Wang Y, Kai H, Wang T, Tang X, Wang X, Pan C. Application of 80-kVp tube voltage, low-concentration contrast agent and iterative reconstruction in coronary CT angiography: evaluation of image quality and radiation dose. Int J Clin Pract 2016; 70 Suppl 9B:B50-5. [PMID: 27577515 DOI: 10.1111/ijcp.12852] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Accepted: 06/15/2016] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND AIM To evaluate image quality and radiation dosage in coronary CT angiography using 80-kVp tube voltage combined with low-concentration contrast media (CM) and iterative reconstruction (IR) for coronary CT angiography (CCTA) and employing dual-source CT without heart-rate control. METHODS 154 patients were randomly assigned to Group A (Control Group, 120-kVp tube voltage, high-concentration CM and filtered back projection reconstruction) and Group B (Low-Dose Group, 80 kVp, low-concentration CM and iterative construction). Two experienced radiologists double-blindly evaluated the following parameters: CT attenuation, signal-noise ratio (SNR), contrast-noise ratio (CNR), radiation dose, size-specific dose estimates (SSDE) and total iodine intake. Pearson correlation analysis was used to assess the relationship between SSDE and BMI. RESULTS 98.1% vessel segments in Group A and 97.6% in Group B passed diagnostics, indicating no significant differences; the average aorta scores and CT attenuation values showed no significant differences between groups. Similar SNR and CNR results were obtained for the two groups, although values were slightly lower in Group A compared with Group B. The Effective Dose in Group B was 63% lower than that in Group A (P<.001). SSDE results were significantly different between the two groups (P<.001) but did not correlate with BMI. Finally, the total iodine intake in Group B was 22.9% lower than that in Group A. CONCLUSIONS Coronary CTA conducted with a low tube voltage of 80 kVp, a low-concentration CM and IR without heart rate control can achieve images of similar quality to those obtained using standard procedures, significantly reducing the associated radiation dose and iodine intake.
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Affiliation(s)
- Qiyong Wu
- Department of Thoracic and Cardiac Surgery, The Second People's Hospital of Changzhou, Affiliated of Nanjing Medical University, Changzhou, China
| | - Yong Wang
- Department of Thoracic and Cardiac Surgery, The Second People's Hospital of Changzhou, Affiliated of Nanjing Medical University, Changzhou, China
| | - Huihua Kai
- Department of Radiology, The Second People's Hospital of Changzhou, Affiliated of Nanjing Medical University, Changzhou, China
| | - Tao Wang
- Department of Radiology, The Second People's Hospital of Changzhou, Affiliated of Nanjing Medical University, Changzhou, China
| | - Xiaoqiang Tang
- Department of Radiology, The Second People's Hospital of Changzhou, Affiliated of Nanjing Medical University, Changzhou, China
| | - Xiaoqin Wang
- Department of Radiology, The Second People's Hospital of Changzhou, Affiliated of Nanjing Medical University, Changzhou, China
| | - Changjie Pan
- Department of Radiology, The Second People's Hospital of Changzhou, Affiliated of Nanjing Medical University, Changzhou, China
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Pure Iterative Reconstruction Improves Image Quality in Computed Tomography of the Abdomen and Pelvis Acquired at Substantially Reduced Radiation Doses in Patients With Active Crohn Disease. J Comput Assist Tomogr 2016; 40:225-33. [PMID: 26760188 DOI: 10.1097/rct.0000000000000358] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
UNLABELLED We assessed diagnostic accuracy and image quality of modified protocol (MP) computed tomography (CT) of the abdomen and pelvis reconstructed using pure iterative reconstruction (IR) in patients with Crohn disease (CD). METHODS Thirty-four consecutive patients with CD were referred with suspected extramural complications. Two contemporaneous CT datasets were acquired in all patients: standard protocol (SP) and MP. The MP and SP protocols were designed to impart radiation exposures of 10% to 20% and 80% to 90% of routine abdominopelvic CT, respectively. The MP images were reconstructed with model-based IR (MBIR) and adaptive statistical IR (ASIR). RESULTS The MP-CT and SP-CT dose length product were 88 (58) mGy.cm (1.27 [0.87] mSv) and 303 [204] mGy.cm (4.8 [2.99] mSv), respectively (P < 0.001). Median diagnostic acceptability, spatial resolution, and contrast resolution were significantly higher and subjective noise scores were significantly lower on SP-ASIR 40 compared with all MP datasets. There was perfect clinical agreement between MP-MBIR and SP-ASIR 40 images for detection of extramural complications. CONCLUSIONS Modified protocol CT using pure IR is feasible for assessment of active CD.
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Botsikas D, Barnaure I, Terraz S, Becker CD, Kalovidouri A, Montet X. Value of liver computed tomography with iodixanol 270, 80 kVp and iterative reconstruction. World J Radiol 2016; 8:693-699. [PMID: 27551339 PMCID: PMC4965353 DOI: 10.4329/wjr.v8.i7.693] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 04/20/2016] [Accepted: 05/11/2016] [Indexed: 02/06/2023] Open
Abstract
AIM: To evaluate the image quality of hepatic multidetector computed tomography (MDCT) with dynamic contrast enhancement.
METHODS: It uses iodixanol 270 mg/mL (Visipaque 270) and 80 kVp acquisitions reconstructed with sinogram affirmed iterative reconstruction (SAFIRE®) in comparison with a standard MDCT protocol. Fifty-three consecutive patients with known or suspected hepatocellular carcinoma underwent 55 CT examinations, with two different four-phase CT protocols. The first group of 30 patients underwent a standard 120 kVp acquisition after injection of Iohexol 350 mg/mL (Accupaque 350®) and reconstructed with filtered back projection. The second group of 25 patients underwent a dual-energy CT at 80-140 kVp with iodixanol 270. The 80 kVp component of the second group was reconstructed iteratively (SAFIRE®-Siemens). All hyperdense and hypodense hepatic lesions ≥ 5 mm were identified with both protocols. Aorta and portal vessels/liver parenchyma contrast to noise ratio (CNR) in arterial phase, hypervascular lesion/liver parenchyma CNR in arterial phase, hypodense lesion/liver parenchyma CNR in portal and late phase were calculated in both groups.
RESULTS: Aorta/liver and focal lesions altogether/liver CNR were higher for the second protocol (P = 0.0078 and 0.0346). Hypervascular lesions/liver CNR was not statistically different (P = 0.86). Hypodense lesion/liver CNR in the portal phase was significantly higher for the second group (P = 0.0107). Hypodense lesion/liver CNR in the late phase was the same for both groups (P = 0.9926).
CONCLUSION: MDCT imaging with 80 kVp with iterative reconstruction and iodixanol 270 yields equal or even better image quality.
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Zhang X, Li S, Liu W, Huang N, Li J, Cheng L, Xu K. Double-low protocol for hepatic dynamic CT scan: Effect of low tube voltage and low-dose iodine contrast agent on image quality. Medicine (Baltimore) 2016; 95:e4004. [PMID: 27368012 PMCID: PMC4937926 DOI: 10.1097/md.0000000000004004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The radiation-induced carcinogenesis from computed tomography (CT) and iodine contrast agent induced nephropathy has attracted international attention. The reduction of the radiation dose and iodine intake in CT scan is always a direction for researchers to strive. The purpose of this study was to evaluate the feasibility of a "double-low" (i.e., low tube voltage and low-dose iodine contrast agent) scanning protocol for dynamic hepatic CT with the adaptive statistical iterative reconstruction (ASIR) in patients with a body mass index (BMI) of 18.5 to 27.9 kg/m.A total of 128 consecutive patients with a BMI between 18.5 and 27.9 kg/m were randomly assigned into 3 groups according to tube voltage, iodine contrast agent, and reconstruction algorithms. Group A (the "double-low" protocol): 100 kVp tube voltage with 40% ASIR, iodixanol at 270 mg I/mL, group B: 120 kVp tube voltage with filtered back projection (FBP), iodixanol at 270 mg I/ mL, and group C: 120 kVp tube voltage with FBP, ioversol at 350 mg I/ mL.The volume CT dose index (CTDIvol) and effective dose (ED) in group A were lower than those in group B and C (all P < 0.01). The iodine intake in group A was decreased by approximately 26.5% than group C, whereas no statistical difference was observed between group A and B (P > 0.05). There was no significant difference of the CT values between group A and C (P > 0.05), which both showed higher CT values than that in group B (P < 0.001). However, no statistic difference was observed in the contrast-to-noise ratio (CNR), the signal-to-noise ratio (SNR), and image-quality scores among the 3 groups (all P > 0.05). Near-perfect consistency of the evaluation for group A, B, and C (Kenall's W = 0.921, 0.874, and 0.949, respectively) was obtained by the 4 readers with respect to the overall image quality.These results suggested that the "double-low" protocol with ASIR algorithm for multi-phase hepatic CT scan can dramatically decrease radiation dose and iodine intake with adequate image quality in patients with BMI of 18.5 to 27.9 kg/m.
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Affiliation(s)
- Xiuli Zhang
- Department of Radiology, Affiliated Hospital of Xuzhou Medical University
| | - Shaodong Li
- Department of Radiology, Affiliated Hospital of Xuzhou Medical University
| | - Wenlou Liu
- Department of Oncology, Zhongnan Hospital of Wuhan University, Wuhan
| | | | - Jingjing Li
- Department of Radiology, Affiliated Hospital of Xuzhou Medical University
- School of Medical Imaging, Xuzhou Medical University, Xuzhou
| | - Li Cheng
- Department of Radiology, Affiliated Hospital of Xuzhou Medical University
| | - Kai Xu
- Department of Radiology, Affiliated Hospital of Xuzhou Medical University
- School of Medical Imaging, Xuzhou Medical University, Xuzhou
- Correspondence: Kai Xu, Department of Radiology, Affiliated Hospital of Xuzhou Medical University, School of Medical Imaging, Xuzhou Medical University, No. 99 West Huai-hai Road, Xuzhou 221004, China (e-mail: )
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Using 80 kVp on a 320-row scanner for hepatic multiphasic CT reduces the contrast dose by 50 % in patients at risk for contrast-induced nephropathy. Eur Radiol 2016; 27:812-820. [PMID: 27240454 DOI: 10.1007/s00330-016-4435-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 05/17/2016] [Accepted: 05/20/2016] [Indexed: 12/13/2022]
Abstract
OBJECTIVES We evaluated the effects of a low contrast material (CM) dose protocol using 80-kVp on the image quality of hepatic multiphasic CT scans acquired on a 320-row CT scanner. METHODS We scanned 30 patients with renal insufficiency (eGFR < 45 mL/min/1.73 m2) using 80-kVp and a CM dose of 300mgI/kg. Another 30 patients without renal insufficiency (eGFR > 60 mL/min/1.73 m2) were scanned with the conventional 120-kVp protocol and the standard CM dose of 600mgI/kg. Quantitative image quality parameters, i.e. CT attenuation, image noise, and the contrast-to-noise ratio (CNR) were compared and the visual image quality was scored on a four-point scale. The volume CT dose index (CTDIvol) and the size-specific dose estimate (SSDE) recorded with the 80- and the 120-kVp protocols were also compared. RESULTS Image noise and contrast enhancement were equivalent for the two protocols. There was no significant difference in the CNR of all anatomic sites and in the visual scores for overall image quality. The CTDIvol and SSDE were approximately 25-30 % lower under the 80-kVp protocol. CONCLUSION Hepatic multiphase CT using 80-kVp on a 320-row CT scanner allowed for a decrease in the CM dose and a reduction in the radiation dose without image quality degradation in patients with renal insufficiency. KEY POINTS • The 80-kVp CT protocol enabled reduction of contrast dose by 50 % • The 80-kVp CT protocol reduced the radiation dose by 25-33 % • There was no degradation in the image quality of the 80-kVp protocol.
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Shuman WP, Chan KT, Busey JM, Mitsumori LM, Koprowicz KM. Dual-energy CT Aortography with 50% Reduced Iodine Dose Versus Single-energy CT Aortography with Standard Iodine Dose. Acad Radiol 2016; 23:611-8. [PMID: 26897602 DOI: 10.1016/j.acra.2015.12.019] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 12/15/2015] [Accepted: 12/21/2015] [Indexed: 12/23/2022]
Abstract
RATIONALE AND OBJECTIVES Because many patients with aortic pathology also have compromised renal function, we wished to investigate dual-energy computed tomography (DECT) aortography with 50% reduced iodine dose compared to single-energy computed tomography (SECT) aortography with standard iodine dose. MATERIALS AND METHODS Fifty patients had DECT aortography with 50% reduced iodine dose. Thirty-four of these patients had prior SECT aortography with standard iodine dose. DECT images were reconstructed at both 50 and 77 keV and were compared to SECT 120 kVp images. Reviewers measured aortic attenuation, image noise, and scored vascular enhancement. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated. Volume CT dose index was recorded. RESULTS Mean iodine dose was 47 g for SECT and 24 g for DECT. Aortic attenuation was highest at reduced iodine dose DECT 50 keV (570 ± 105 Hounsfield units [HU]) compared to 77 keV (239 ± 40 HU) or to standard iodine dose SECT 120 kVp (356 ± 69 HU) (P < 0.05). Image noise was greatest at 50 keV compared to 77 keV and 120 kVp (P < 0.05) but was similar between 77 keV and 120 kVp (P > 0.05). SNR and CNR were the same at 50 keV and 120 kVp (P > 0.05). Mean vascular enhancement scores were all above 3.0 (good, typical enhancement). Volume CT dose index was 11.7 mGy for DECT and 11.8 mGy for SECT (P = 0.37). CONCLUSIONS DECT aortography with 50% reduced iodine reconstructed at 50 keV resulted in significantly greater aortic attenuation, good subjective vascular enhancement, and comparable SNR and CNR compared to standard iodine dose SECT. DECT image noise at 77 keV was similar to SECT at 120 kVp.
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Affiliation(s)
- William P Shuman
- Department of Radiology, University of Washington School of Medicine, Box 357115, 1959 NE Pacific Street, Seattle, WA 98195.
| | - Keith T Chan
- Department of Radiology, University of Washington School of Medicine, Box 357115, 1959 NE Pacific Street, Seattle, WA 98195
| | - Janet M Busey
- Department of Radiology, University of Washington School of Medicine, Box 357115, 1959 NE Pacific Street, Seattle, WA 98195
| | - Lee M Mitsumori
- Department of Radiology, University of Washington School of Medicine, Box 357115, 1959 NE Pacific Street, Seattle, WA 98195
| | - Kent M Koprowicz
- Department of Radiology, University of Washington School of Medicine, Box 357115, 1959 NE Pacific Street, Seattle, WA 98195
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Lehti L, Nyman U, Söderberg M, Björses K, Gottsäter A, Wassélius J. 80-kVp CT angiography for endovascular aneurysm repair follow-up with halved contrast medium dose and preserved diagnostic quality. Acta Radiol 2016; 57:279-86. [PMID: 25829479 DOI: 10.1177/0284185115577251] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 02/12/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Follow-up of endovascular aneurysm repair (EVAR) with life-long computed tomography angiography (CTA) surveillance exposes patients with impaired renal function to repeated risks of contrast medium-induced nephropathy (CIN). PURPOSE To retrospectively compare vascular attenuation, image noise, contrast-to-noise ratio (CNR), subjective image quality and effective radiation dose (mSv) for CTA with a 16-multirow detector CT (MDCT) equipment at 80 kVp after EVAR using a contrast medium (CM) dose that is half of that used at 120 kVp. MATERIAL AND METHODS Forty patients with estimated glomerular filtration rate (eGFR) <45 mL/min underwent 80-kVp CTA with 160 mg I/kg, and 40 patients with eGFR ≥45 mL/min 120-kVp CTA with 320 mg I/kg (maximum dose weight, 80 kg). Arterial phase analysis included vascular attenuation, image noise and CNR, and calculated effective dose. Subjective image quality was assessed on a 4-point scale by two blinded readers at three different levels as well as overall. RESULTS Median values in the 80/120 kVp cohorts were: age, 74-75 years; body weight, 77/80 kg; BMI 24/27 kg/m(2); CM dose, 13/25 gram-iodine; gram-iodine/GFR ratio, 0.35/0.38; mean aortic attenuation, 313/326 HU; image noise, 26/32 HU; CNR 10-11; subjective image quality score, 3.0-3.5 (Reader 1) and 3.0-3.3 (Reader 2); number of non-diagnostic examinations, 0/1; and effective dose, 4.5/5.1 mSv. There was no statistically significant difference in aortic CNR and effective dose between the 80 and 120 kVp cohorts. CONCLUSION 80 kVp 16-MDCT with halved CM dose tailored to body weight for CTA follow-up of EVAR may provide satisfactory diagnostic results compared to common standards and be beneficial for patients at risk of CIN, though the present CT equipment may limit the use of the method to patients below 90 kg or with a BMI below 35 kg/m(2).
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Affiliation(s)
- Leena Lehti
- Vascular Center, Skåne University Hospital, Malmö, Sweden
| | - Ulf Nyman
- Department of Clinical Sciences, Malmö, Faculty of Medicine, Lund University, Lund Sweden
| | - Marcus Söderberg
- Medical Radiation Physics, Skåne University Hospital, Malmö, Sweden
| | | | | | - Johan Wassélius
- Department of Neuroradiology, Skåne University Hospital, Lund, Sweden
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