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Zhang Y, Yuan D, Qi K, Zhang M, Zhang W, Wei N, Li L, Lv P, Gao J, Liu J. Feasibility Analysis of Individualized Low Flow Rate Abdominal Contrast-Enhanced Computed Tomography in Chemotherapy Patients: Dual-Source Computed Tomography With Low Tube Voltage. J Comput Assist Tomogr 2024:00004728-990000000-00319. [PMID: 38693081 DOI: 10.1097/rct.0000000000001624] [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
PURPOSE The aim of the study is to investigate the feasibility of using dual-source computed tomography (CT) combined with low flow rate and low tube voltage for postchemotherapy image assessment in cancer patients. METHODS Ninety patients undergoing contrast-enhanced CT scans of the upper abdomen were prospectively enrolled and randomly assigned to groups A, B, and C (n = 30 each). In group A, patients underwent scans at 120 kVp with 448 mgI/kg. Patients in group B underwent scans at 100 kVp with 336 mgI/kg. Patient in group C underwent scans at 70 kVp with of 224 mgI/kg. Quantitative measurements including the CT number, standard deviation of CT number, signal-to-noise ratio, contrast-to-noise ratio, subjective reader scores, and the volume and flow rate of contrast agent were evaluated for each group. RESULTS There was no statistically significant difference in the subjective image scores within the three groups except for the kidney (all P > 0.05). Group C showed significantly higher CT values, lower noise levels, and higher signal-to-noise ratio and contrast-to-noise ratio values in the majority of the regions of interest compared to the other groups (P < 0.05). In group C, the contrast agent dose was decreased by 46% compared to group A (79.48 ± 12.24 vs 42.7 ± 8.6, P < 0.01), and the contrast agent injection rate was reduced by 22% (2.7 ± 0.41 vs 2.1 ± 0.4, P < 0.01). CONCLUSIONS The use of 70 kVp tube voltage combined with low iodine flow rates prove to be a more effective approach in solving the challenge of compromised blood vessels in postchemotherapy tumor patients, without reducing image quality and diagnostic confidence.
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Affiliation(s)
- Yicun Zhang
- From the The Department of Radiology, The First Affiliated Hospital of Zhengzhou, University, Zhengzhou
| | - Dian Yuan
- From the The Department of Radiology, The First Affiliated Hospital of Zhengzhou, University, Zhengzhou
| | - Ke Qi
- From the The Department of Radiology, The First Affiliated Hospital of Zhengzhou, University, Zhengzhou
| | - Mengyuan Zhang
- From the The Department of Radiology, The First Affiliated Hospital of Zhengzhou, University, Zhengzhou
| | - Weiting Zhang
- From the The Department of Radiology, The First Affiliated Hospital of Zhengzhou, University, Zhengzhou
| | - Nannan Wei
- From the The Department of Radiology, The First Affiliated Hospital of Zhengzhou, University, Zhengzhou
| | | | - Peijie Lv
- From the The Department of Radiology, The First Affiliated Hospital of Zhengzhou, University, Zhengzhou
| | - Jianbo Gao
- From the The Department of Radiology, The First Affiliated Hospital of Zhengzhou, University, Zhengzhou
| | - Jie Liu
- From the The Department of Radiology, The First Affiliated Hospital of Zhengzhou, University, Zhengzhou
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Sauranen S, Mäkelä T, Kaasalainen T, Kortesniemi M. Dual-energy computed tomography quality control: Initial experiences with a semi-automatic analysis tool. Phys Med 2024; 118:103211. [PMID: 38237302 DOI: 10.1016/j.ejmp.2024.103211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 12/02/2023] [Accepted: 01/04/2024] [Indexed: 02/10/2024] Open
Abstract
PURPOSE A quality control (QC) system for dual-energy CT (DECT) was developed. The scope of the QC system was to monitor both the constancy of the CT images and the software used in calculating the DECT derived maps. Longitudinal analysis was based on a standard imaging protocol, a commercial multi-energy phantom, and a semi-automatic analysis tool. METHODS The phantom consisted of an elliptical body section with round slots for interchangeable inserts. It was scanned with 90kVp/Sn150kVp, automatic tube current modulation, and 9.6 mGy CTDIvol. From the two conventional CT images, scanner manufacturer's software was used to provide virtual monoenergetic images at two different energies, effective atomic number (Zeff) maps, and iodine concentration maps. The images were analyzed using an open-source tool allowing user-selected statistics of interest. The means and standard deviations of the phantom background and the iodine, calcium, and water inserts were recorded. The QC tool is available at github.com/tomakela/dectqatool. RESULTS The obtained results were generally highly consistent over time, except for the smaller diameter iodine inserts. A small change inZeff was observed after a DECT software update. The developed QC tool aided the analysis robustness: the segmentations were modifiable when needed, and small rotations or air bubbles in the water insert were easily corrected. CONCLUSION The developed QC system provided easy-to-use workflow for constancy measurements. A small deviation due to change in the post-processing was detected. The proposed imaging protocol and analysis steps, and the reported measurement variations can aid in determining action levels for DECT QC.
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Affiliation(s)
- S Sauranen
- Department of Physics, University of Helsinki, Helsinki, Finland; HUS Diagnostic Center, Radiology, University of Helsinki and Helsinki University Hospital, P.O. Box 340, 00290 Helsinki, Finland.
| | - T Mäkelä
- Department of Physics, University of Helsinki, Helsinki, Finland; HUS Diagnostic Center, Radiology, University of Helsinki and Helsinki University Hospital, P.O. Box 340, 00290 Helsinki, Finland
| | - T Kaasalainen
- HUS Diagnostic Center, Radiology, University of Helsinki and Helsinki University Hospital, P.O. Box 340, 00290 Helsinki, Finland
| | - M Kortesniemi
- HUS Diagnostic Center, Radiology, University of Helsinki and Helsinki University Hospital, P.O. Box 340, 00290 Helsinki, Finland
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Lyu P, Li Z, Chen Y, Wang H, Liu N, Liu J, Zhan P, Liu X, Shang B, Wang L, Gao J. Deep learning reconstruction CT for liver metastases: low-dose dual-energy vs standard-dose single-energy. Eur Radiol 2024; 34:28-38. [PMID: 37532899 DOI: 10.1007/s00330-023-10033-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 05/28/2023] [Accepted: 06/05/2023] [Indexed: 08/04/2023]
Abstract
OBJECTIVES To assess image quality and liver metastasis detection of reduced-dose dual-energy CT (DECT) with deep learning image reconstruction (DLIR) compared to standard-dose single-energy CT (SECT) with DLIR or iterative reconstruction (IR). METHODS In this prospective study, two groups of 40 participants each underwent abdominal contrast-enhanced scans with full-dose SECT (120-kVp images, DLIR and IR algorithms) or reduced-dose DECT (40- to 60-keV virtual monochromatic images [VMIs], DLIR algorithm), with 122 and 106 metastases, respectively. Groups were matched by age, sex ratio, body mass index, and cross-sectional area. Noise power spectrum of liver images and task-based transfer function of metastases were calculated to assess the noise texture and low-contrast resolution. The image noise, signal-to-noise ratios (SNR) of liver and portal vein, liver-to-lesion contrast-to-noise ratio (LLR), lesion conspicuity, lesion detection rate, and the subjective image quality metrics were compared between groups on 1.25-mm reconstructed images. RESULTS Compared to 120-kVp images with IR, 40- and 50-keV VMIs with DLIR showed similar noise texture and LLR, similar or higher image noise and low-contrast resolution, improved SNR and lesion conspicuity, and similar or better perceptual image quality. When compared to 120-kVp images with DLIR, 50-keV VMIs with DLIR had similar low-contrast resolution, SNR, LLR, lesion conspicuity, and perceptual image quality but lower frequency noise texture and higher image noise. For the detection of hepatic metastases, reduced-dose DECT by 34% maintained observer lesion detection rates. CONCLUSION DECT assisted with DLIR enables a 34% dose reduction for detecting hepatic metastases while maintaining comparable perceptual image quality to full-dose SECT. CLINICAL RELEVANCE STATEMENT Reduced-dose dual-energy CT with deep learning image reconstruction is as accurate as standard-dose single-energy CT for the detection of liver metastases and saves more than 30% of the radiation dose. KEY POINTS • The 40- and 50-keV virtual monochromatic images (VMIs) with deep learning image reconstruction (DLIR) improved lesion conspicuity compared with 120-kVp images with iterative reconstruction while providing similar or better perceptual image quality. • The 50-keV VMIs with DLIR provided comparable perceptual image quality and lesion conspicuity to 120-kVp images with DLIR. • The reduction of radiation by 34% by DLIR in low-keV VMIs is clinically sufficient for detecting low-contrast hepatic metastases.
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Affiliation(s)
- Peijie Lyu
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Zhen Li
- Department of Interventional Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Yan Chen
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Huixia Wang
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Nana Liu
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Jie Liu
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Pengchao Zhan
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Xing Liu
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Bo Shang
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Luotong Wang
- CT Imaging Research Center, GE Healthcare China, Beijing, China
| | - Jianbo Gao
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China.
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Reduced Iodinated Contrast Media Administration in Coronary CT Angiography on a Clinical Photon-Counting Detector CT System: A Phantom Study Using a Dynamic Circulation Model. Invest Radiol 2023; 58:148-155. [PMID: 36165932 DOI: 10.1097/rli.0000000000000911] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PURPOSE The aim of this study was to evaluate strategies to reduce contrast media volumes for coronary computed tomography (CT) angiography on a clinical first-generation dual-source photon-counting detector (PCD)-CT system using a dynamic circulation phantom. MATERIALS AND METHODS Coronary CT angiograph is an established method for the assessment of coronary artery disease that relies on the administration of iodinated contrast media. Reduction of contrast media volumes while maintaining diagnostic image quality is desirable. In this study, a dynamic phantom containing a 3-dimensional-printed model of the thoracic aorta and coronary arteries was evaluated using a clinical contrast injection protocol with stepwise reduced contrast agent concentrations (100%, 75%, 50%, 40%, 30%, and 20% contrast media content of the same 50 mL bolus, resulting in iodine delivery rates of 1.5, 1.1, 0.7, 0.6, 0.4 and 0.3 gl/s) on a first-generation, dual-source PCD-CT. Polychromatic images (T3D) and virtual monoenergetic images were reconstructed in the range of 40 to 70 keV in 5-keV steps. Attenuation and noise were measured in the coronary arteries and background material and the contrast-to-noise ratio (CNR) were calculated. Attenuation of 350 HU and a CNR of the reference protocol at 70 keV were regarded as sufficient for simulation of diagnostic purposes. Vessel sharpness and noise power spectra were analyzed for the aforementioned reconstructions. RESULTS The standard clinical contrast protocol (bolus with 100% contrast) yielded diagnostic coronary artery attenuation for all tested reconstructions (>398 HU). A 50% reduction in contrast media concentration demonstrated sufficient attenuation of the coronary arteries at 40 to 55 keV (>366 HU). Virtual monoenergetic image reconstructions of 40 to 45 and 40 keV allowed satisfactory attenuation of the coronary arteries for contrast concentrations of 40% and 30% of the original protocol. A reduction of contrast agent concentration to 20% of the initial concentration provided insufficient attenuation in the target vessels for all reconstructions. The highest CNR was found for virtual monoenergetic reconstructions at 40 keV for all contrast media injection protocols, yielding a sufficient CNR at a 50% reduction of contrast agent concentration. CONCLUSIONS Using virtual monoenergetic image reconstructions at 40 keV on a dual-source PCD-CT system, contrast media concentration could be reduced by 50% to obtain diagnostic attenuation and objective image quality for coronary CT angiography in a dynamic vessel phantom. These initial feasibility study results have to be validated in clinical studies.
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Iodine footprint: Moving towards environmental responsibility. J Neuroradiol 2023; 50:1-2. [PMID: 36400241 DOI: 10.1016/j.neurad.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Li G, Zhang L, Liu T, Wang J, Cao Z, Lu G, Zhang L. Exploration of thoracoabdominal aortic mixed reality optimisation and its clinical application value in type A aortic dissection. Eur Radiol 2023; 33:4313-4322. [PMID: 36622412 DOI: 10.1007/s00330-022-09372-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 10/08/2022] [Accepted: 12/08/2022] [Indexed: 01/10/2023]
Abstract
OBJECTIVES This study aimed to explore the feasibility of low-dose computed tomography (CT)-based mixed reality and its clinical role in type A aortic dissection (TAAD) operations. METHODS Eighty-seven patients diagnosed with TAAD were prospectively enrolled and underwent thoracoabdominal aorta mixed reality. They were randomly divided into a low-dose mixed reality group, a conventional mixed reality group and a conventional thoracoabdominal aorta computed tomography angiography (CTA) group. Three-dimensional modelling, mixed reality and CT reconstruction technology were selected. The radiation dose and image quality were compared using Student's t test. Doctors with different seniorities evaluated the clinical application value of thoracoabdominal aorta mixed reality using a Likert scale. The consistency was assessed using the Cohen kappa coefficient (k). The Pearson chi-square test was used to test the correlation of perioperative index results in TAAD operations. RESULTS Low-dose CT technology can be effectively applied to thoracoabdominal aorta mixed reality and reduces the radiation dose by approximately 59% and the operation time and auxiliary cardiopulmonary bypass time by approximately 22% and 29%, respectively. The subjective scores of doctors with different seniorities on the clinical application value of thoracoabdominal aorta mixed reality were higher than those of thoracoabdominal aorta CTA (all p > 0.05). CONCLUSIONS Low-dose CT can be effectively used in thoracoabdominal aortic mixed reality to reduce the radiation dose while ensuring quality. Low-dose thoracoabdominal aortic mixed reality has clinical application value and can effectively reduce the operation time and auxiliary cardiopulmonary bypass time in TAAD operations. KEY POINTS • Low-dose CT technology can ensure the mixed reality quality of the thoracoabdominal aorta with a radiation dose reduction of approximately 59%. • Compared with thoracoabdominal aorta CTA, low-dose thoracoabdominal aorta mixed reality can reduce the operation time and auxiliary cardiopulmonary bypass time by approximately 20% and 29%, respectively, in TAAD operations. • The application value of low-dose thoracoabdominal aorta mixed reality in operation scheme formulation, operation risk assessment, operation navigation and diagnosis and treatment under safe distance was greater than that of thoracoabdominal aorta CTA in TAAD.
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Affiliation(s)
- Guan Li
- Department of Radiology, Jinling Hospital, Medical School of Nanjing University, 305 Eastern Zhongshan Road, Nanjing, 210002, China
| | - Lei Zhang
- Department of Cardiovascular Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Tao Liu
- Department of Cardiovascular Surgery, General Hospital of Northern Theater Command, Shenyang, China
| | - Jinbao Wang
- Department of Radiology, General Hospital of Northern Theater Command, Shenyang, China
| | - Zhiqiang Cao
- Department of Digital Lab, Shengjing Hospital Affiliated with China Medical University, Shenyang, China
| | - Guangming Lu
- Department of Radiology, Jinling Hospital, Medical School of Nanjing University, 305 Eastern Zhongshan Road, Nanjing, 210002, China.
| | - Longjiang Zhang
- Department of Radiology, Jinling Hospital, Medical School of Nanjing University, 305 Eastern Zhongshan Road, Nanjing, 210002, China.
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A feasibility study of different GSI noise indexes and concentrations of contrast medium in hepatic CT angiography of overweight patients: image quality, radiation dose, and iodine intake. Jpn J Radiol 2023; 41:669-679. [PMID: 36607550 DOI: 10.1007/s11604-022-01384-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 12/28/2022] [Indexed: 01/07/2023]
Abstract
PURPOSE To conduct a comparative study of image quality, radiation dose, and iodine intake in hepatic computed tomographic angiography (CTA) of overweight patients with different Gemstone Spectral Imaging (GSI) noise indexes combined with different concentrations of contrast medium. MATERIALS AND METHODS Ninety patients with a body mass index of ≥ 25 kg/m2 were divided into three groups (A, B and C), each with 30 patients. The three groups underwent hepatic CTA with different NI of 7, 11 and 15, respectively, and were injected with different iodine concentrations of 370, 350 and 320 mgI/mL, respectively. Five sets of images at 40-60 keV (interval, 5 keV) were reconstructed in each group. The CT value, image noise, contrast-to-noise ratio (CNR) and subjective score of the hepatic artery and vein, and portal vein in different monochromatic image sets were analyzed to select the optimal energy level in each group. The differences in CT value, image noise, CNR and a subjective score of hepatic artery and vein, portal vein in the optimal monochromatic images among the three groups were compared, the volume CT dose index (CTDIvol) and dose-length product (DLP) were recorded, and the effective dose and iodine intake were calculated. RESULTS The 40 keV was determined to be the optimal energy level for the monochromatic image sets in each group. No significant group differences were noted in the CT value, image noise, CNR, and subjective image scores of the hepatic artery and vein, and portal vein for the optimal monochromatic images (P > 0.05). Compared with group A, the effective dose and iodine intake in group B were reduced by 50.18% and 9.3%, and by 58.12% and 14.23% in group C, respectively. CONCLUSION A low-concentration contrast medium combined with a high-noise GSI index in hepatic CTA of overweight patients can reduce the radiation dose and iodine intake while ensuring image quality.
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Multi-Energy CT Applications. Radiol Clin North Am 2023; 61:1-21. [DOI: 10.1016/j.rcl.2022.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Bae JS, Lee JM, Kim SW, Park S, Han S, Yoon JH, Joo I, Hong H. Low-contrast-dose liver CT using low monoenergetic images with deep learning-based denoising for assessing hepatocellular carcinoma: a randomized controlled noninferiority trial. Eur Radiol 2022; 33:4344-4354. [PMID: 36576547 DOI: 10.1007/s00330-022-09298-x] [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: 07/01/2022] [Revised: 09/29/2022] [Accepted: 11/13/2022] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Low monoenergetic images obtained using noise-reduction techniques may reduce CT contrast media requirements. We aimed to investigate the effectiveness of low-contrast-dose CT using dual-energy CT and deep learning-based denoising (DLD) techniques in patients at high risk of hepatocellular carcinoma (HCC). METHODS We performed a prospective, randomized controlled noninferiority trial at a tertiary hospital between June 2019 and August 2020 (NCT04027556). Patients at high risk of HCC were randomly assigned (1:1) to the standard-contrast-dose group or low-contrast-dose group, which targeted a 40% reduction in contrast medium dose based on lean body weight. HCC conspicuity on arterial phase images was the primary endpoint with a noninferiority margin of 0.2. Images were independently assessed by three radiologists; model-based iterative reconstruction (MBIR) images of the standard-contrast-dose group and low monoenergetic (50-keV) DLD images of the low-contrast-dose group were compared using a generalized estimating equation. RESULTS Ninety participants (age 59 ± 10 years; 68 men) were analyzed. Compared with the standard-contrast-dose group (n = 47), 40% less contrast media was used in the low-contrast-dose group (n = 43) (107.0 ± 17.1 mL vs. 64.5 ± 11.3 mL, p < 0.001). In the arterial phase, HCC conspicuity on 50-keV DLD images in the low-contrast-dose group was noninferior to that of MBIR images in the standard-contrast-dose group (2.92 vs. 2.56; difference, 0.36; 95% confidence interval, -0.13 to ∞; p = 0.013). CONCLUSIONS The contrast dose in liver CT can be reduced by 40% without impairing HCC conspicuity when using 50-keV and DLD techniques. KEY POINTS • In the arterial phase, hepatocellular carcinoma conspicuity on 50-keV deep learning-based denoising images in the low-contrast-dose group was noninferior to that of model-based iterative reconstruction images in the standard-contrast-dose group. • HCC detection was comparable between 50-keV deep learning-based denoising images in the low-contrast-dose group and model-based iterative reconstruction images in the standard-contrast-dose group.
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Affiliation(s)
- Jae Seok Bae
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Jeong Min Lee
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea. .,Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea. .,Institute of Radiation Medicine, Seoul National University Medical Research Center, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
| | - Se Woo Kim
- Department of Radiology, Armed Forces Daejeon Hospital, 90, Jaun-ro, Yuseong-gu, Daejeon, 34059, Republic of Korea
| | - Sungeun Park
- Department of Radiology, Konkuk University Medical Center, 120-1, Neungdong-ro, Gwangjin-gu, Seoul, 05030, Republic of Korea
| | - Seungchul Han
- Department of Radiology, Samsung Medical Center, 81, Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea
| | - Jeong Hee Yoon
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Ijin Joo
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Hyunsook Hong
- Division of Biostatistics, Medical Research Collaborating Center, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
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Magnetic Resonance Neuroimaging Contrast Agents of Nanomaterials. BIOMED RESEARCH INTERNATIONAL 2022; 2022:6790665. [PMID: 36082155 PMCID: PMC9448598 DOI: 10.1155/2022/6790665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/25/2022] [Accepted: 08/03/2022] [Indexed: 11/17/2022]
Abstract
Since the early 1980s when MRI imaging technology was put into clinical use, the number of MRI clinical tests has steadily increased by more than 10% every year. At the same time, exogenous MRI contrast agents have also been developed with the development of MRI technology. However, there are still challenges in the preparation of contrast agents for magnetic resonance imaging, such as how to prepare high-efficiency contrast agents with high stability and low biological toxicity. In order to study the contrast agent with simple preparation method, low cost, and good imaging effect, a magnetic resonance contrast agent was prepared by magnetic nanoparticles. By acting on magnetic resonance imaging detection method, and using polymer ligands to synthesize magnetic nanoparticles, experiments and tests of P(MA-alt-VAc) polymer ligand-modified magnetic nanoparticles were carried out. The experimental results showed that when nanoparticles containing different iron ion concentrations were incubated with DC 2.4 normal cells for 48 hours, the cell viability was still higher than 80% at concentrations up to 200 μm. It shows that the nanoparticle has high cell activity and good biological adaptability. The transverse relaxation (r2) value of the nanoparticles in aqueous solution at 37°C and 1.5 T magnetic field is 231.1 m−1 s−1, which is much higher than that of PTMP-PMAA (r2 = 35.1 mM−1 s−1), which is also more than five times the relaxation of SHU-555C (r2 = 44 mM−1 s−1). It shows that the nanoparticles prepared in this paper have good effect and can be used as a contrast agent in human brain for magnetic resonance imaging.
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Santos Armentia E, Martín Noguerol T, Silva Priegue N, Delgado Sánchez-Gracián C, Trinidad López C, Prada González R. Strengths, weaknesses, opportunities, and threat analysis of dual-energy CT in head and neck imaging. RADIOLOGIA 2022; 64:333-347. [DOI: 10.1016/j.rxeng.2022.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/19/2022] [Indexed: 11/29/2022]
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Santos Armentia E, Martín-Noguerol T, Silva Priegue N, Delgado Sánchez-Gracián C, Trinidad López C, Prada González R. Análisis de las fortalezas, oportunidades, debilidades y amenazas de la tomografía computarizada de doble energía en el diagnóstico por la imagen de la cabeza y el cuello. RADIOLOGIA 2022. [DOI: 10.1016/j.rx.2022.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Yu X, Cai A, Wang L, Zheng Z, Wang Y, Wang Z, Li L, Yan B. Framelet tensor sparsity with block matching for spectral CT reconstruction. Med Phys 2022; 49:2486-2501. [PMID: 35142376 DOI: 10.1002/mp.15529] [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: 03/24/2021] [Revised: 01/11/2022] [Accepted: 01/21/2022] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Spectral computed tomography (CT) based on the photon-counting detection system has the capability to produce energy-discriminative attenuation maps of objects with a single scan. However, the insufficiency of photons collected into the narrow energy bins results in high quantum noise levels causing low image quality. This work aims to improve spectral CT image quality by developing a novel regularization based on framelet tensor prior. METHODS First, similar patches are extracted from highly correlated inter-channel images in spectral and spatial domains, and stacked to form a third-order tensor after vectorization along the energy channels. Second, the framelet tensor nuclear norm (FTNN) is introduced and applied to construct the regularization to exploit the sparsity embedded in nonlocal similarity of spectral images, and thus the reconstruction problem is modeled as a constrained optimization. Third, an iterative algorithm is proposed by utilizing the alternating direction method of multipliers framework in which efficient solvers are developed for each subproblem. RESULTS Both numerical simulations and real data verifications were performed to evaluate and validate the proposed FTNN based method. Compared to the analytic, TV-based, and the state-of-the-art tensor-based methods, the proposed method achieves higher numerical accuracy on both reconstructed CT images and decomposed material maps in the mouse data indicating the capability in noise suppression and detail preservation of the proposed method. CONCLUSIONS A framelet tensor sparsity-based iterative algorithm is proposed for spectral reconstruction. The qualitative and quantitative comparisons show a promising improvement of image quality, indicating its promising potential in spectral CT imaging. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Xiaohuan Yu
- Henan Key Laboratory of Imaging and Intelligent Processing, PLA Strategic Support Force Information Engineering University, Zhengzhou, China
| | - Ailong Cai
- Henan Key Laboratory of Imaging and Intelligent Processing, PLA Strategic Support Force Information Engineering University, Zhengzhou, China
| | - Linyuan Wang
- Henan Key Laboratory of Imaging and Intelligent Processing, PLA Strategic Support Force Information Engineering University, Zhengzhou, China
| | - Zhizhong Zheng
- Henan Key Laboratory of Imaging and Intelligent Processing, PLA Strategic Support Force Information Engineering University, Zhengzhou, China
| | - Yizhong Wang
- Henan Key Laboratory of Imaging and Intelligent Processing, PLA Strategic Support Force Information Engineering University, Zhengzhou, China
| | - Zhe Wang
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Lei Li
- Henan Key Laboratory of Imaging and Intelligent Processing, PLA Strategic Support Force Information Engineering University, Zhengzhou, China
| | - Bin Yan
- Henan Key Laboratory of Imaging and Intelligent Processing, PLA Strategic Support Force Information Engineering University, Zhengzhou, China
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Wang X, Liang P, Lv P, Li R, Hou P, Gao J. Clinical characteristics and CT features of hepatic epithelioid haemangioendothelioma and comparison with those of liver metastases. Insights Imaging 2022; 13:9. [PMID: 35050424 PMCID: PMC8776937 DOI: 10.1186/s13244-021-01143-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 12/14/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To analyse clinical characteristics and computer tomography (CT) findings of hepatic epithelioid haemangioendothelioma (HEH) and to determine differential features compared with liver metastasis (LM). METHODS This retrospective study included 80 patients with histopathologically confirmed HEH (n = 20) and LM (n = 60) of different primary tumours who underwent dynamic contrast-enhanced CT scans. CT findings included the location, contour, size, number, margin, and density of lesions, the patterns and degree of contrast enhancement of lesions, vascular invasion and changes in other organs. The enhancement ratio (ER) and tumour-to-normal parenchyma ratio (TNR) were calculated. Receiver operating characteristic curves (ROCs) were used to determine areas under the curve (AUCs). RESULTS About 65% of HEH lesions were located in submarginal areas. Significant differences were observed between HEH and LM patients in age, sex, and tumour marker positivity (p < 0.05). HEH showed minimal to slight enhancement, thin ring-like enhancement in arterial phase, and slight, homogeneous, progressive enhancement in the portal phase. HEH presented capsule retraction, and the "target" sign and the "lollipop" sign were significantly more frequent than in LM (p < 0.05). The ER and TNR in the arterial phase of HEH were lower than those of LM (p < 0.05). AUCs of ER and TNR in the arterial phase were 0.74 and 0.73, respectively. CONCLUSION Lesions in subcapsular locations, capsular retraction, slight and thin ring-like enhancement, "target" and "lollipop" signs and lower ER and TNR in the arterial phase may represent important features of HEH compared with LM.
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Affiliation(s)
- Xiaopeng Wang
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, East Jianshe Road, Zhengzhou, 450052, Henan Province, China
| | - Pan Liang
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, East Jianshe Road, Zhengzhou, 450052, Henan Province, China
| | - Peijie Lv
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, East Jianshe Road, Zhengzhou, 450052, Henan Province, China
| | - Rui Li
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, East Jianshe Road, Zhengzhou, 450052, Henan Province, China
| | - Ping Hou
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, East Jianshe Road, Zhengzhou, 450052, Henan Province, China
| | - Jianbo Gao
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, No. 1, East Jianshe Road, Zhengzhou, 450052, Henan Province, China.
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Optimize scan timing in abdominal multiphase CT: Bolus tracking with an individualized post-trigger delay. Eur J Radiol 2021; 148:110139. [PMID: 35021118 DOI: 10.1016/j.ejrad.2021.110139] [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: 10/12/2021] [Revised: 12/24/2021] [Accepted: 12/28/2021] [Indexed: 11/23/2022]
Abstract
PURPOSE To conduct a head-to-head comparison in terms of image quality and diagnostic confidence between an individualized post-trigger delay and a conventional fixed post-trigger delay in bolus tracking abdominal multiphase CT. METHODS AND MATERIALS Abdominal multiphase CT was performed in 104 patients with either of the two bolus tracking strategies: an individualized post-trigger delay (group A) and fixed post-trigger delay of 11 s (group B). All CT scan parameters and contrast media protocol parameters were consistent between the two groups. Quantitative parameters (organs and blood vessels enhancement, image noise, signal-to-noise ratios [SNRs] and contrast-to-noise ratios [CNRs]) and qualitative visual parameters (overall image quality and diagnostic confidence) were compared. Quantitative and qualitative image quality for the two groups were compared using the Mann-Whitney U and independent sample t test. Degrees of agreement between two radiologists were evaluated using the Kappa analysis. RESULTS In the arterial phase (AP), images of group A provided higher attenuation (P ≤ 0.001). Although SNRs of liver, pancreas and aorta were similar in AP between the two groups, CNRs of liver, pancreas and portal vein in group A were significantly higher than those in group B (all P values ≤ 0.002). The overall subjective image quality and diagnostic confidence between the two groups were similar (P = 0.809; P = 0.768). CONCLUSION Compared to a fixed post-trigger delay using bolus tracking, application of an individualized post-trigger delay can optimize the objective image quality in arterial phase without compromising diagnostic quality in abdominal multiphase CT.
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Double Low-Dose Dual-Energy Liver CT in Patients at High-Risk of HCC: A Prospective, Randomized, Single-Center Study. Invest Radiol 2021; 55:340-348. [PMID: 31917765 DOI: 10.1097/rli.0000000000000643] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES The aim of this study was to investigate the clinical feasibility of the simultaneous reduction of radiation and contrast doses using spectral computed tomography (CT) in patients at high-risk for hepatocellular carcinoma. MATERIALS AND METHODS Between May 2017 and March 2018, this prospective study recruited participants at risk of hepatocellular carcinoma with body mass indexes less than 30 and randomly assigned them to either the standard-dose group or the double low-dose group, which targeted 30% reductions in both radiation and contrast media (NCT03045445). Lesion conspicuity as a primary endpoint and lesion detection rates were then compared between hybrid iterative reconstruction (iDose) images of standard-dose group and low monoenergetic (50 keV) images of double low-dose group. Qualitative and quantitative image noise and contrast were also compared between the 2 groups. Participants and reviewers were blinded for scan protocols and reconstruction algorithms. Lesion conspicuity was analyzed using generalized estimating equation analysis. Lesion detection was evaluated using weighted jackknife alternative free-response receiver operating characteristic analysis. RESULTS Sixty-seven participants (male-to-female ratio, 59:8; mean age, 64 ± 9 years) were analyzed. Compared with the standard-dose group (n = 32), significantly lower CTDIvol (8.8 ± 1.7 mGy vs 6.1 ± 0.6 mGy) and contrast media (116.9 ± 15.7 mL vs 83.1 ± 9.9 mL) were utilized in the double low-dose group (n = 35; P < 0.001). Comparative analysis demonstrated that lesion conspicuity was significantly higher on 50 keV images of double low-dose group than on iDose images of standard dose on both arterial (2.62 [95% confidence interval (CI), 2.31-2.93] vs 2.02 [95% CI, 1.73-2.30], respectively, P = 0.004) and portal venous phases (2.39 [95% CI, 2.11-2.67] vs 1.88 [95% CI, 1.67-2.10], respectively, P = 0.005). No differences in lesion detection capability were observed between the 2 groups (figure of merit: 0.63 in standard-dose group; 0.65, double low-dose group; P = 0.52). Fifty kiloelectronvolt images of double low-dose group showed better subjective image noise and contrast than iDose image of standard-dose group on arterial and portal venous phases (P < 0.001 for all). Contrast-to-noise ratio of the aorta and portal vein was also higher in double low-dose group than in standard-dose group (P < 0.001 for all), whereas there was no significant difference of quantitative image noise between the 2 groups on arterial and portal phases (P = 0.4~0.5). CONCLUSIONS Low monoenergetic spectral CT images (50 keV) can provide better focal liver lesion conspicuity than hybrid iterative reconstruction image of standard-dose CT in nonobese patients while using lower radiation and contrast media doses.
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Wang Q, Wu W, Deng S, Zhu Y, Yu H. Locally linear transform based three-dimensional gradient L 0 -norm minimization for spectral CT reconstruction. Med Phys 2020; 47:4810-4826. [PMID: 32740956 DOI: 10.1002/mp.14420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 06/14/2020] [Accepted: 07/21/2020] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Spectral computed tomography (CT) is proposed by extending the conventional CT along the energy dimension. One newly implementation is to employ an energy-discriminating photon counting detector (PCD), which can distinguish photon energy and divide a whole x-ray spectrum into several energy bins with appropriate post-processing steps. The state-of-the-art PCD-based spectral CT has superior energy resolution and material distinguishability, and it further has a great potential in both medical and industrial applications. To improve the reconstruction quality and decomposition accuracy, in this work, we propose an optimization-based spectral CT reconstruction method with an innovational sparsity constraint. METHODS We first employ a locally linear transform to the reconstructed channel images, and the structural similarity along the spectral dimension is effectively converted to a one-dimensional (1D) gradient sparsity. Then, combining the prior knowledge of piecewise constant in the spatial domain (e.g., a two-dimensional (2D) gradient sparsity feature), we unify both spectral and spatial dimensions and establish a joint three-dimensional (3D) gradient sparsity. In addition, we use the L 0 -norm to measure the proposed sparsity and incorporate it as a smoothness constraint to concretize a general optimization framework. Furthermore, we develop the corresponding iterative algorithm to solve the optimization problem. RESULTS Both visual results and quantitative indexes of numerical simulations and phantom experiments demonstrate the proposed method outperform the conventional filtered backprojection (FBP), total variation (TV), 2D L0 -norm (L0 ), and TV with low rank (TVLR)-based methods. From the image and ROI comparisons, we find the proposed method performs well in noise suppression, detail maintenance, and decomposition accuracy. However, the FBP suffers severe noise, the TV and L0 are difficult to work consistently among different energy bins, and the TVLR fails to avoid gray value shift. The image quality assessments, such as peak signal-to-noise ratio (PSNR), normal mean absolute deviation (NMAD). and structural similarity (SSIM), also consistently indicate the proposed method can effectively removing noise and keeping fine structures in both channel-wise reconstructions and material decompositions. CONCLUSIONS By employing a locally linear transform, the structural similarity among spectral channel images is converted to a 1D gradient sparsity and the gray value shift is effectively avoided when the difference measurement is minimized. The 3D L0 -norm jointly and uniformly measures the gradient sparsity in both spectral and spatial dimensions. The cooperation of locally linear transform and 3D L0 -norm well reinforces the global sparse features and keeps the correlation along spectral dimension without bringing gray-value distortions. The corresponding constraint optimization model is fast and stably solved by using an alternative direction technique. Both numerical simulations and phantom experiments confirm the superior performance of the proposed method in noise suppression, structure maintenance, and accurate decomposition.
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Affiliation(s)
- Qian Wang
- Department of Electrical and Computer Engineering, University of Massachusetts Lowell, Lowell, MA, 01854, USA
| | - Weiwen Wu
- Department of Electrical and Computer Engineering, University of Massachusetts Lowell, Lowell, MA, 01854, USA.,Key Lab of Optoelectronic Technology and Systems, Ministry of Education, Chongqing University, Chongqing, 400044, China
| | - Shiwo Deng
- School of Mathematical Sciences, Capital Normal University, Beijing, 100048, China
| | - Yining Zhu
- School of Mathematical Sciences, Capital Normal University, Beijing, 100048, China
| | - Hengyong Yu
- Department of Electrical and Computer Engineering, University of Massachusetts Lowell, Lowell, MA, 01854, USA
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Lennartz S, Große Hokamp N, Zäske C, Zopfs D, Bratke G, Glauner A, Maintz D, Persigehl T, Chang DH, Hickethier T. Virtual monoenergetic images preserve diagnostic assessability in contrast media reduced abdominal spectral detector CT. Br J Radiol 2020; 93:20200340. [PMID: 32644824 DOI: 10.1259/bjr.20200340] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVES To investigate if low-keV virtual monoenergetic images (VMI40keV) from abdominal spectral detector CT (SDCT) with reduced intravenous contrast media application (RCM) provide abdominal assessment similar to conventional images with standard contrast media (SCM) dose. METHODS 78 patients with abdominal SDCT were retrospectively included: 41 patients at risk for adverse reactions who received 44 RCM examinations with 50 ml and 37 patients who underwent 44 SCM examinations with 100 ml of contrast media (CM) and who were matched for effective body diameters. RCM, SCM images and RCM-VMI40keV were reconstructed. Attenuation and signal-to-noise ratio (SNR) of liver, pancreas, kidneys, lymph nodes, psoas muscle, aorta and portal vein were assessed ROIs-based. Contrast-to-noise ratios (CNR) of lymph nodes vs aorta/portal vein were calculated. Two readers evaluated organ/vessel contrast, lymph node delineation, image noise and overall assessability using 4-point Likert scales. RESULTS RCM were inferior to SCM images in all quantitative/qualitative criteria. RCM-VMI40keV and SCM images showed similar lymph node and muscle attenuation (p = 0.83,0.17), while for all other ROIs, RCM-VMI40keV showed higher attenuation (p ≤ 0.05). SNR was comparable between RCM-VMI40keV and SCM images (p range: 0.23-0.99). CNR of lymph nodes was highest in RCM-VMI40keV (p ≤ 0.05). RCM-VMI40keV received equivalent or higher scores than SCM in all criteria except for organ contrast, overall assessability and image noise, where SCM were superior (p ≤ 0.05). However, RCM-VMI40keV received proper or excellent scores in 88.6/94.2/95.4% of the referring cases. CONCLUSIONS VMI40keV counteract contrast deterioration in CM reduced abdominal SDCT, facilitating diagnostic assessment. ADVANCES IN KNOWLEDGE SDCT-derived VMI40keV provide adequate depiction of vessels, organs and lymph nodes even at notable CM reduction.
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Affiliation(s)
- Simon Lennartz
- Institute for Diagnostic and Interventional Radiology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Straße 62, 50937, Cologne, Germany.,Department of Radiology, Massachusetts General Hospital, Harvard Medial School, 55 Fruit Street, White 270, Boston, MA 02114, USA.,Else Kröner Forschungskolleg Clonal Evolution in Cancer, University Hospital Cologne,Weyertal 115b, 50931, Cologne, Germany
| | - Nils Große Hokamp
- Institute for Diagnostic and Interventional Radiology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Charlotte Zäske
- Institute for Diagnostic and Interventional Radiology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - David Zopfs
- Institute for Diagnostic and Interventional Radiology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Grischa Bratke
- Institute for Diagnostic and Interventional Radiology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Andreas Glauner
- Institute for Diagnostic and Interventional Radiology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - David Maintz
- Institute for Diagnostic and Interventional Radiology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Thorsten Persigehl
- Institute for Diagnostic and Interventional Radiology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - De-Hua Chang
- Institute for Diagnostic and Interventional Radiology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Straße 62, 50937, Cologne, Germany.,Department of Radiology, University Medical Center Heidelberg, Heidelberg, Germany
| | - Tilman Hickethier
- Institute for Diagnostic and Interventional Radiology, University of Cologne, Faculty of Medicine and University Hospital Cologne, Kerpener Straße 62, 50937, Cologne, Germany
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A Novel Blind Restoration and Reconstruction Approach for CT Images Based on Sparse Representation and Hierarchical Bayesian-MAP. ALGORITHMS 2019. [DOI: 10.3390/a12080174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Computed tomography (CT) image reconstruction and restoration are very important in medical image processing, and are associated together to be an inverse problem. Image iterative reconstruction is a key tool to increase the applicability of CT imaging and reduce radiation dose. Nevertheless, traditional image iterative reconstruction methods are limited by the sampling theorem and also the blurring of projection data will propagate unhampered artifact in the reconstructed image. To overcome these problems, image restoration techniques should be developed to accurately correct a wide variety of image degrading effects in order to effectively improve image reconstruction. In this paper, a blind image restoration technique is embedded in the compressive sensing CT image reconstruction, which can result in a high-quality reconstruction image using fewer projection data. Because a small amount of data can be obtained by radiation in a shorter time, high-quality image reconstruction with less data is equivalent to reducing radiation dose. Technically, both the blurring process and the sparse representation of the sharp CT image are first modeled as a serial of parameters. The sharp CT image will be obtained from the estimated sparse representation. Then, the model parameters are estimated by a hierarchical Bayesian maximum posteriori formulation. Finally, the estimated model parameters are optimized to obtain the final image reconstruction. We demonstrate the effectiveness of the proposed method with the simulation experiments in terms of the peak signal to noise ratio (PSNR), and structural similarity index (SSIM).
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Lin YM, Chiou YY, Wu MH, Huang SS, Shen SH. Postablation assessment of hepatocellular carcinoma using dual-energy CT: Comparison of half versus standard iodine contrast medium. PLoS One 2019; 14:e0219577. [PMID: 31287838 PMCID: PMC6615706 DOI: 10.1371/journal.pone.0219577] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 06/26/2019] [Indexed: 12/15/2022] Open
Abstract
This retrospective study was aimed to evaluate the reduced iodine load on image quality and diagnostic performance in multiphasic hepatic CT using a novel monoenergetic reconstruction algorithm (nMERA) in assessment of local tumor progression after radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC). Ninety patients who underwent CT 1 month after RFA of HCC. Forty-five patients had multiphasic hepatic dual-energy CT with a half-reduced contrast medium (HRCM) of 277.5 mg I/kg. The nMERA (40-70-keV) images were reconstructed in each phase. Another 45 patients received a standard contrast medium (SCM) of 555 mg I/kg, and the images were reconstructed as a simulated 120-kVp images. Primary outcome was accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) in assessment of local tumor progression. Additional advanced assessments included the image noise, attenuation value, contrast-to-noise ratio (CNR), and subjective image quality between the groups. The accuracy, sensitivity and specificity of nMERA HRCM images were 95.7%, 100% and 93.9% for 40 keV, 95.7%, 85.7% and 100% for 50 keV, 83.0%, 42.8% and 100% for 60 keV, and 83.0%, 42.9% and 100% for 70 keV. The AUROC was 0.99, 0.99, 0.94, and 0.93 for 40-70 keV nMERA HRCM images, respectively. Compared with simulated 120-kVp SCM images, nMERA HRCM images demonstrated comparable noise at 70-keV (P < 0.05), and comparable CNR at 40- and 50-keV (P < 0.05). nMERA DECT enables the contrast medium to be reduced to up to 50% in multiphasic hepatic CT while preserving diagnostic accuracy.
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Affiliation(s)
- Yuan-Mao Lin
- Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Yi-You Chiou
- Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Mei-Han Wu
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Medical Imaging, Cheng Hsin General Hospital, Taipei, Taiwan
| | - Shan Su Huang
- Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Shu-Huei Shen
- Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
- * E-mail:
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21
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Yue D, Li Fei S, Jing C, Ru Xin W, Rui Tong D, Ai Lian L, Luo YH. The relationship between calcium (water) density and age distribution in adult women with spectral CT: initial result compared to bone mineral density by dual-energy X-ray absorptiometry. Acta Radiol 2019; 60:762-768. [PMID: 30249113 DOI: 10.1177/0284185118801139] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Calcium (water) density (DCa(Wa)) of gemstone spectral imaging by spectral computed tomography (CT) is a new method of evaluating bone structures. PURPOSE To investigate age-related change of DCa(Wa) of a chosen lumbar vertebra in adult women with spectral CT and the correlation between the DCa(Wa) and bone mineral density (BMD) of dual-energy X-ray absorptiometry (DXA). MATERIAL AND METHODS A total of 305 adult women underwent spectral CT, 127 of whom simultaneously underwent DXA. All the patients were divided into 11 subgroups based on age. DCa(Wa) and BMD were measured at the second lumbar vertebra on the calcium (water)-based material decomposition images of spectral CT and DXA, respectively. A one-way analysis of variance (ANOVA) was performed for the difference of the measurements among adjacent age subgroups. Pearson correlation was used to assess the association between age and DCa(Wa), age and BMD, as well as DCa(Wa) and BMD. RESULTS There was a significant negative correlation between DCa(Wa) and age (r = -0.719) as well as BMD and age(r = -0.851). The mean DCa(Wa) of L2 vertebral body was significantly different between the 40-44- and 45-49-, 45-49- and 50-54-, 55-59- and 60-64-, 65-69- and 70-74-year-old age subgroups. BMD was significantly different between the 35-39- and 40-44-, 45-49- and 50-54-, and 65-69- and 70-74-year-old age subgroups. There was a significant positive correlation between DCa(Wa) and BMD. CONCLUSIONS The DCa(Wa) of lumbar vertebra by spectral CT demonstrated similar age distribution as BMD of DXA and could be used as a method of measuring the vertebral bone mineral density in adult women.
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Affiliation(s)
- Dong Yue
- Department of Radiology, Cancer Hospital of China Medical University, LiaoNing Cancer Hospital, Shenyang, Liaoning, PR China
| | - Sun Li Fei
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, LiaoNing, PR China
| | - Chen Jing
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, LiaoNing, PR China
| | - Wang Ru Xin
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, LiaoNing, PR China
| | - Dong Rui Tong
- Department of Radiology, Cancer Hospital of China Medical University, LiaoNing Cancer Hospital, Shenyang, Liaoning, PR China
| | - Liu Ai Lian
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, LiaoNing, PR China
| | - Ya Hong Luo
- Department of Radiology, Cancer Hospital of China Medical University, LiaoNing Cancer Hospital, Shenyang, Liaoning, PR China
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Nagayama Y, Nakaura T, Oda S, Taguchi N, Utsunomiya D, Funama Y, Kidoh M, Namimoto T, Sakabe D, Hatemura M, Yamashita Y. Dual-layer detector CT of chest, abdomen, and pelvis with a one-third iodine dose: image quality, radiation dose, and optimal monoenergetic settings. Clin Radiol 2018; 73:1058.e21-1058.e29. [DOI: 10.1016/j.crad.2018.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 08/24/2018] [Indexed: 12/12/2022]
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23
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Lv P, Zhou Z, Liu J, Chai Y, Zhao H, Guo H, Marin D, Gao J. Can virtual monochromatic images from dual-energy CT replace low-kVp images for abdominal contrast-enhanced CT in small- and medium-sized patients? Eur Radiol 2018; 29:2878-2889. [DOI: 10.1007/s00330-018-5850-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 09/29/2018] [Accepted: 10/22/2018] [Indexed: 01/25/2023]
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Wu W, Zhang Y, Wang Q, Liu F, Chen P, Yu H. Low-dose spectral CT reconstruction using image gradient ℓ 0-norm and tensor dictionary. APPLIED MATHEMATICAL MODELLING 2018; 63:538-557. [PMID: 32773921 PMCID: PMC7409840 DOI: 10.1016/j.apm.2018.07.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Spectral computed tomography (CT) has a great superiority in lesion detection, tissue characterization and material decomposition. To further extend its potential clinical applications, in this work, we propose an improved tensor dictionary learning method for low-dose spectral CT reconstruction with a constraint of image gradient ℓ 0-norm, which is named as ℓ 0TDL. The ℓ 0TDL method inherits the advantages of tensor dictionary learning (TDL) by employing the similarity of spectral CT images. On the other hand, by introducing the ℓ 0-norm constraint in gradient image domain, the proposed method emphasizes the spatial sparsity to overcome the weakness of TDL on preserving edge information. The split-bregman method is employed to solve the proposed method. Both numerical simulations and real mouse studies are perform to evaluate the proposed method. The results show that the proposed ℓ 0TDL method outperforms other competing methods, such as total variation (TV) minimization, TV with low rank (TV+LR), and TDL methods.
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Affiliation(s)
- Weiwen Wu
- Key Lab of Optoelectronic Technology and Systems, Ministry of Education, Chongqing University, Chongqing 400044, China
- Department of Electrical and Computer Engineering, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - Yanbo Zhang
- Department of Electrical and Computer Engineering, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - Qian Wang
- Department of Electrical and Computer Engineering, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - Fenglin Liu
- Key Lab of Optoelectronic Technology and Systems, Ministry of Education, Chongqing University, Chongqing 400044, China
- Engineering Research Center of Industrial Computed Tomography Nondestructive Testing, Ministry of Education, Chongqing University, Chongqing 400044, China
- Corresponding author at: Key Lab of Optoelectronic Technology and Systems, Ministry of Education, Chongqing University, Chongqing 400044, China. (F. Liu)
| | - Peijun Chen
- Key Lab of Optoelectronic Technology and Systems, Ministry of Education, Chongqing University, Chongqing 400044, China
| | - Hengyong Yu
- Department of Electrical and Computer Engineering, University of Massachusetts Lowell, Lowell, MA 01854, USA
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Yue D, Fan Rong C, Ning C, Liang H, Ai Lian L, Ru Xin W, Ya Hong L. Reduction of metal artifacts from unilateral hip arthroplasty on dual-energy CT with metal artifact reduction software. Acta Radiol 2018; 59:853-860. [PMID: 28899125 DOI: 10.1177/0284185117731475] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background The evaluation of hip arthroplasty is a challenge in computed tomography (CT). The virtual monochromatic spectral (VMS) images with metal artifact reduction software (MARs) in spectral CT can reduce the artifacts and improve the image quality. Purpose To evaluate the effects of VMS images and MARs for metal artifact reduction in patients with unilateral hip arthroplasty. Material and Methods Thirty-five patients underwent dual-energy CT. Four sets of VMS images without MARs and four sets of VMS images with MARs were obtained. Artifact index (AI), CT number, and SD value were assessed at the periprosthetic region and the pelvic organs. The scores of two observers for different images and the inter-observer agreement were evaluated. Results The AIs in 120 and 140 keV images were significantly lower than those in 80 and 100 keV images. The AIs of the periprosthetic region in VMS images with MARs were significantly lower than those in VMS images without MARs, while the AIs of pelvic organs were not significantly different. VMS images with MARs improved the accuracy of CT numbers for the periprosthetic region. The inter-observer agreements were good for all the images. VMS images with MARs at 120 and 140 keV had higher subjective scores and could improve the image quality, leading to reliable diagnosis of prosthesis-related problems. Conclusion VMS images with MARs at 120 and 140 keV could significantly reduce the artifacts from hip arthroplasty and improve the image quality at the periprosthetic region but had no obvious advantage for pelvic organs.
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Affiliation(s)
- Dong Yue
- Department of Radiology, Cancer Hospital of China Medical University, LiaoNing Cancer Hospital, LiaoNing, PR China
| | - Cheng Fan Rong
- Department of Radiology, Cancer Hospital of China Medical University, LiaoNing Cancer Hospital, LiaoNing, PR China
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, LiaoNing, PR China
| | - Cai Ning
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, LiaoNing, PR China
| | - Hu Liang
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, LiaoNing, PR China
| | - Liu Ai Lian
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, LiaoNing, PR China
| | - Wang Ru Xin
- Department of Radiology, The First Affiliated Hospital of Dalian Medical University, LiaoNing, PR China
| | - Luo Ya Hong
- Department of Radiology, Cancer Hospital of China Medical University, LiaoNing Cancer Hospital, LiaoNing, PR China
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Ma G, YU Y, Duan H, Dou Y, Jia Y, Zhang X, Yang C, Chen X, Han D, Guo C, He T. Subtraction CT angiography in head and neck with low radiation and contrast dose dual-energy spectral CT using rapid kV-switching technique. Br J Radiol 2018; 91:20170631. [PMID: 29412008 PMCID: PMC6223275 DOI: 10.1259/bjr.20170631] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 01/15/2018] [Accepted: 02/01/2018] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To investigate the application of low radiation and contrast dose spectral CT angiology using rapid kV-switching technique in the head and neck with subtraction method for bone removal. METHODS This prospective study was approved by the local ethics committee. 64 cases for head and neck CT angiology were randomly divided into Groups A (n = 32) and B (n = 32). Group A underwent unenhanced CT with 100 kVp, 200 mA and contrast-enhanced CT with spectral CT mode with body mass index-dependent low dose protocols. Group B used conventional helical scanning with 120 kVp, auto mA for noise index of 12 HU (Hounsfield unit) for both the unenhanced and contrast-enhanced CT. Subtraction images were formed by subtracting the unenhanced images from enhanced images (with the 65 keV-enhanced spectral CT image in Group A). CT numbers and their standard deviations in aortic arch, carotid arteries, middle cerebral artery and air were measured in the subtraction images. The signal-to-noise ratio and contrast-to-noise ratio for the common and internal carotid arteries and middle cerebral artery were calculated. Image quality in terms of bone removal effect was evaluated by two experienced radiologists independently and blindly using a 4-point system. Radiation dose and total iodine load were recorded. Measurements were statistically compared between the two groups. RESULTS The two groups had same demographic results. There was no difference in the CT number, signal-to-noise and contrast-to-noise ratio values for carotid arteries and middle cerebral artery in the subtraction images between the two groups (p > 0.05). However, the bone removal effect score [median (min-max)] in Group A [4 (3-4)] was rated better than in Group B [3 (2-4)] (p < 0.001), with excellent agreement between the two observers (κ > 0.80). The radiation dose in Group A (average of 2.64 mSv) was 57% lower than the 6.18 mSv in Group B (p < 0.001). The total iodine intake in Group A was 13.5g, 36% lower than the 21g in Group B. CONCLUSION Spectral CT imaging with rapid kV-switching in the subtraction angiography in head and neck provides better bone removal with significantly reduced radiation and contrast dose compared with conventional subtraction method. Advances in knowledge: This novel method provides better bone removal with significant radiation and contrast dose reduction compared with the conventional subtraction CT, and maybe used clinically to protect the thyroid gland and ocular lenses from unnecessary high radiation.
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Affiliation(s)
- Guangming Ma
- Department of Diagnostic Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, China
| | - Yong YU
- Department of Diagnostic Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, China
| | - Haifeng Duan
- Department of Diagnostic Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, China
| | - Yuequn Dou
- Department of Diagnostic Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, China
| | - Yongjun Jia
- Department of Diagnostic Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, China
| | - Xirong Zhang
- Department of Diagnostic Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, China
| | - Chuangbo Yang
- Department of Diagnostic Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, China
| | - Xiaoxia Chen
- Department of Diagnostic Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, China
| | - Dong Han
- Department of Diagnostic Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, China
| | - Changyi Guo
- Department of Diagnostic Radiology, The Second Affiliated Hospital of the Shannxi University of Traditional Chinese Medicine, Xianyang, China
| | - Taiping He
- Department of Diagnostic Radiology, Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang, China
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Li W, Li A, Wang B, Niu X, Cao X, Wang X, Shi H. Automatic spectral imaging protocol and iterative reconstruction for radiation dose reduction in typical hepatic hemangioma computed tomography with reduced iodine load: a preliminary study. Br J Radiol 2018; 91:20170978. [PMID: 29714501 DOI: 10.1259/bjr.20170978] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE To evaluate the effect of automatic spectral imaging protocol selection (ASIS) and adaptive statistical iterative reconstruction (ASiR) technique in the reduction of radiation and contrast medium dose in typical hepatic hemangioma (HH) dual energy spectral CT (DEsCT). METHODS 62 patients with suspected HH were randomly divided into two groups equally: Group A, conventional 120-kVp CT with standard iodine load; Group B, DEsCT with ASIS technique and reduced iodine load, two sets of monochromatic spectral images were reconstructed: 69 keV level with 30% ASiR (Group B1) and 52 keV level with 50% ASiR (Group B2). The radiation and total iodine dose, quantitative analysis (standard deviation value, contrast-to-noise and contrast enhancement ratio) and qualitative analysis were evaluated. RESULTS No difference was observed in the standard deviation values, subjective image noise, and the diagnostic acceptability score among the three groups (p > 0.05). Contrast to noise [Group B2 vs A, B1 in arterial phase (AP): 19.51 ± 6.29 vs 15.77 ± 5.93, 11.46 ± 2.84; Group B2 vs A, B1 in portal venous phase (PVP): 9.96 ± 2.18 vs 8.19 ± 3.04, 6.01 ± 1.82], contrast enhancement ratio (Group B2 vs A, B1 in AP: 6.88 ± 2.01 vs 5.47 ± 2.01, 4.15 ± 1.28; Group B2 vs A, B1 in PVP: 5.58 ± 1.02 vs 4.54 ± 1.13, 3.49 ± 0.83), and the lesion conspicuity score (Group B2 vs A, B1 in AP: 3.93 ± 0.26 vs 3.45 ± 0.51, 3.10 ± 0.49; Group B2 vs A, B1 in PVP: 3.90 ± 0.31 vs 3.48 ± 0.57, 3.14 ± 0.44) for Group B2 were higher than those in Group A and B1 (p < 0.05). Compared to Group A, the radiation dose and total iodine dose in Group B were reduced by 30 and 41%, respectively (radiation dose in Group B vs A: 5.53 ± 1.59 vs 7.91± 2.71 mSv; iodine dose in Group B vs A: 18.85 ± 2.88 vs 31.78±3.89 ml; p < 0.05). CONCLUSION DEsCT with ASIS and ASiR technique can reduce the radiation dose without image quality degradation as compared to the conventional 120-kVp CT. The monochromatic spectral images at 52 keV level with 50% ASiR allows the reduction in total iodine dose without deteriorating diagnostic performance. Advances in knowledge: ASIS combined with ASiR technique, by using monochromatic spectral images at 52 keV level, represents a feasible imaging protocol to reduce the radiation and total iodine dose in assessment of typical HH.
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Affiliation(s)
- Wei Li
- 1 Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University , Jinan, Shandong , China
| | - Aiyin Li
- 1 Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University , Jinan, Shandong , China
| | - Bin Wang
- 2 Department of Medical Imaging, ZhangQiu district hospital of TCM , Jinan, Shandong , China
| | - Xiuyuan Niu
- 2 Department of Medical Imaging, ZhangQiu district hospital of TCM , Jinan, Shandong , China
| | - Xin Cao
- 1 Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University , Jinan, Shandong , China
| | - Xinyi Wang
- 1 Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University , Jinan, Shandong , China
| | - Hao Shi
- 1 Department of Medical Imaging, Qianfoshan Hospital Affiliated to Shandong University , Jinan, Shandong , China
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Fang T, Deng W, Law MWM, Luo L, Zheng L, Guo Y, Chen H, Huang B. Comparison of image quality and radiation exposure between conventional imaging and gemstone spectral imaging in abdominal CT examination. Br J Radiol 2018; 91:20170448. [PMID: 29762057 DOI: 10.1259/bjr.20170448] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE To compare patients' image quality and radiation exposure between gemstone spectral imaging (GSI) with rapid kV switching technique and conventional polychromatic imaging (CPI) performed in abdominal CT examinations. METHODS Adult patients who were referred to abdominal CT from October 2015 to March 2016 were enrolled. Unenhanced CT with CPI mode and tri-phase (arterial/portal/delayed phase) contrast-enhanced scan with GSI mode were performed with different protocols respectively. Regions of interest (ROIs) were drawn on muscle and fat. Parametric results of the image noise, signal-to-noise ratio (SNR) and clinical image quality in these regions between the monochromatic images reconstructed at 65 keV and conventional polychromatic images were compared. Radiation dose was also compared between CPI and GSI. RESULTS 43 patients were recruited. Compared to conventional imaging, the noise level was generally not significantly different between GSI images in arterial phase and portal phase, and significantly higher (around 10%) in delayed phase. The SNR of GSI in portal phase was significantly higher than that of conventional imaging, and was similar between arterial phase/delayed phase and conventional imaging. The clinical image quality between conventional imaging and GSI was generally not significantly different. The dose length product was reduced by 0.3-20.1% in GSI compared to conventional imaging. CONCLUSION GSI reduces the radiation exposure slightly, however maintains or even improves image quality. These results may warrant the application of GSI in patients referred for abdominal CT. Advances in knowledge: Compared to CPI, GSI reduces the radiation exposure slightly, however maintains or even improves image quality in abdominal CT. These findings may warrant the application of GSI in patients referred for abdominal CT.
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Affiliation(s)
- Tianqi Fang
- 1 National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Health Science Centre, Shenzhen University , Shenzhen , China
| | - Wei Deng
- 2 Department of Radiology, Guangzhou Panyu Central Hospital , Guangzhou , China.,3 Medical Imaging Institute of Panyu , Guangzhou , China
| | | | - Liangping Luo
- 5 Medical Imaging Center, The First Affiliated Hospital of Jinan University , Guangzhou , China
| | - Liyun Zheng
- 1 National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Health Science Centre, Shenzhen University , Shenzhen , China
| | - Ying Guo
- 6 CT Research Centre (CTRC), GE Healthcare , China
| | - Hanwei Chen
- 2 Department of Radiology, Guangzhou Panyu Central Hospital , Guangzhou , China.,3 Medical Imaging Institute of Panyu , Guangzhou , China
| | - Bingsheng Huang
- 1 National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Health Science Centre, Shenzhen University , Shenzhen , China.,3 Medical Imaging Institute of Panyu , Guangzhou , China
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Son BG, Kim MJ, Park MH, Kim K, Kim J, Kim SY, Lee KJ, Choi SH, Kim AY, Park SH. Two Small Intravenous Catheters for High-Rate Contrast Medium Injection for Computed Tomography in Patients Lacking Superficial Veins to Accommodate a Large Catheter. Korean J Radiol 2018; 19:489-497. [PMID: 29713227 PMCID: PMC5904476 DOI: 10.3348/kjr.2018.19.3.489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 10/30/2017] [Indexed: 01/29/2023] Open
Abstract
Objective To prospectively investigate the feasibility of using 2 small intravenous catheters for high-rate computed tomography (CT) contrast injection in patients lacking superficial veins capable of accommodating ≤ 20-gauge catheters. Materials and Methods Sixty-eight consecutive eligible adults referred for dynamic liver CT were enrolled; 58 had previously undergone liver CT, including 8 that experienced extravasation. Two 22- or 24-gauge catheters were placed in all patients after 2–5 venipunctures, and 2 mL/kg of contrast agent (370 mg I/mL) was split-administered through both catheters to achieve total flow rate of 4 mL/s. Patients' experience and examination success rate, defined as uneventful scans completed at 4 mL/s or at < 4 mL/s achieving standard image quality in all phases, were analyzed. Quantitative hepatic signal-to-noise and hepatic vascular contrast-to-noise ratios (CNRs) were compared with 30 control examinations scanned at 4 mL/s using an 18-gauge catheter. Results One case each of extravasation and severe injection pain caused the examination to be aborted. Success rate was 88.2% (60/68; 54 patients scanned at 4 mL/s, 6 at 3.5–3.9 mL/s). Fifty-five of 58 patients (94.8%) that had past CT regarded the venipuncture as more tolerable than (n = 36) or similar to (n = 19) past experiences; 45 of 58 patients (77.6%) found contrast injection less painful than (n = 35) or similar to (n = 10) past experiences. When compared with control examinations, signal-to-noise ratio was similar in all phases (p ≥ 0.502), but the hepatic arterial CNR in arterial phase was slightly inferior (p ≤ 0.047). Conclusion Using 2 small intravenous catheters can effectively achieve high-rate CT contrast injection in patients lacking adequate superficial veins.
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Affiliation(s)
- Bum Gu Son
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Min Jung Kim
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Myeung Hwa Park
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Kyoungsook Kim
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Jiyu Kim
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Se-Young Kim
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Kyung Jin Lee
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Sang Hyun Choi
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Ah Young Kim
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Seong Ho Park
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
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Yin XP, Gao BL, Li CY, Zuo ZW, Xu YJ, Wang JN, Liu HJ, Liang GL. Automatic spectral imaging protocol selection combined with iterative reconstruction can enhance image quality and decrease radiation and contrast dosage in abdominal CT angiography. Jpn J Radiol 2018; 36:345-350. [PMID: 29616398 DOI: 10.1007/s11604-018-0734-3] [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: 01/09/2018] [Accepted: 03/28/2018] [Indexed: 10/17/2022]
Abstract
PURPOSE To investigate the effect of automatic spectral imaging protocol selection (ASIS) and adaptive statistical iterative reconstruction (ASIR) technology in reducing radiation and contrast dosage. METHODS Sixty-four patients were randomly divided into two groups for abdominal computed tomography (CT): the experiment group with ASIS plus 50% ASIR and the control with 120 kVp voltage. RESULTS The CT dose-index volume decreased by 23.68 and 23.57% and the dose-length product dropped by 25.59 and 18.45% in the arterial and portal venous phases, respectively, in the experiment than control group. The contrast dose was reduced by 16.86% in the experiment group. In the 55 keV + 50% ASIR group, the arterial contrast-to-noise ratio and scores were significantly (P < 0.05) higher than in the control group in the arterial phase while the portal contrast-to-noise ratio and scores were not significantly different between the two groups (P > 0.05). CONCLUSION The ASIS technique plus 50% ASIR can enhance image quality of the abdominal structures while decreasing the radiation and contrast dosage compared with the conventional scan mode.
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Affiliation(s)
- Xiao-Ping Yin
- CT/MRI Room, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, People's Republic of China
| | - Bu-Lang Gao
- Department of Medical Research, Shijiazhuang First Hospital, Shijiazhuang, 050011, Hebei, People's Republic of China.
| | - Cai-Ying Li
- Department of Medical Imaging, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, Hebei, People's Republic of China
| | - Zi-Wei Zuo
- CT/MRI Room, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, People's Republic of China
| | - Ying-Jin Xu
- CT/MRI Room, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, People's Republic of China
| | - Jia-Ning Wang
- CT/MRI Room, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, People's Republic of China
| | - Huai-Jun Liu
- Department of Medical Imaging, The Second Hospital of Hebei Medical University, Shijiazhuang, 050000, Hebei, People's Republic of China
| | - Guang-Lu Liang
- CT/MRI Room, Affiliated Hospital of Hebei University, Baoding, 071000, Hebei, People's Republic of China
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van Hamersvelt RW, Eijsvoogel NG, Mihl C, de Jong PA, Schilham AMR, Buls N, Das M, Leiner T, Willemink MJ. Contrast agent concentration optimization in CTA using low tube voltage and dual-energy CT in multiple vendors: a phantom study. Int J Cardiovasc Imaging 2018. [PMID: 29516228 DOI: 10.1007/s10554-018-1329-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We investigated the feasibility and extent to which iodine concentration can be reduced in computed tomography angiography imaging of the aorta and coronary arteries using low tube voltage and virtual monochromatic imaging of 3 major dual-energy CT (DECT) vendors. A circulation phantom was imaged with dual source CT (DSCT), gemstone spectral imaging (GSI) and dual-layer spectral detector CT (SDCT). For each scanner, a reference scan was acquired at 120 kVp using routine iodine concentration (300 mg I/ml). Subsequently, scans were acquired at lowest possible tube potential (70, 80, 80 kVp, respectively), and DECT-mode (80/150Sn, 80/140 and 120 kVp, respectively) in arterial phase after administration of iodine (300, 240, 180, 120, 60, 30 mg I/ml). Objective image quality was evaluated using attenuation, CNR and dose corrected CNR (DCCNR) measured in the aorta and left main coronary artery. Average DCCNR at reference was 227.0, 39.7 and 60.2 for DSCT, GSI and SDCT. Maximum iodine concentration reduction without loss of DCCNR was feasible down to 180 mg I/ml (40% reduced) for DSCT (DCCNR 467.1) and GSI (DCCNR 46.1) using conventional CT low kVp, and 120 mg I/ml (60% reduced) for SDCT (DCCNR 171.5) using DECT mode. Low kVp scanning and DECT allows for 40-60% iodine reduction without loss in image quality compared to reference. Optimal scan protocol and to which extent varies per vendor. Further patient studies are needed to extend and translate our findings to clinical practice.
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Affiliation(s)
- Robbert W van Hamersvelt
- Department of Radiology, University Medical Center Utrecht, Utrecht University, P. O. Box 85500, 3508 GA, Utrecht, The Netherlands.
| | - Nienke G Eijsvoogel
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Casper Mihl
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Pim A de Jong
- Department of Radiology, University Medical Center Utrecht, Utrecht University, P. O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Arnold M R Schilham
- Department of Radiology, University Medical Center Utrecht, Utrecht University, P. O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Nico Buls
- Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
| | - Marco Das
- Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Tim Leiner
- Department of Radiology, University Medical Center Utrecht, Utrecht University, P. O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Martin J Willemink
- Department of Radiology, University Medical Center Utrecht, Utrecht University, P. O. Box 85500, 3508 GA, Utrecht, The Netherlands
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Feng C, Zhu D, Zou X, Li A, Hu X, Li Z, Hu D. The combination of a reduction in contrast agent dose with low tube voltage and an adaptive statistical iterative reconstruction algorithm in CT enterography: Effects on image quality and radiation dose. Medicine (Baltimore) 2018; 97:e0151. [PMID: 29561422 PMCID: PMC5895339 DOI: 10.1097/md.0000000000010151] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
To investigate the subjective and quantitative image quality and radiation exposure of CT enterography (CTE) examination performed at low tube voltage and low concentration of contrast agent with adaptive statistical iterative reconstruction (ASIR) algorithm, compared with conventional CTE.One hundred thirty-seven patients with suspected or proved gastrointestinal diseases underwent contrast enhanced CTE in a multidetector computed tomography (MDCT) scanner. All cases were assigned to 2 groups. Group A (n = 79) underwent CT with low tube voltage based on patient body mass index (BMI) (BMI < 23 kg/m, 80 kVp; BMI ≥ 23 kg/m, 100 kVp) and low concentration of contrast agent (270 mg I/mL), the images were reconstructed with standard filtered back projection (FBP) algorithm and 50% ASIR algorithm. Group B (n = 58) underwent conventional CTE with 120 kVp and 350 mg I/mL contrast agent, the images were reconstructed with FBP algorithm. The computed tomography dose index volume (CTDIvol), dose length product (DLP), effective dose (ED), and total iodine dosage were calculated and compared. The CT values, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) of the normal bowel wall, gastrointestinal lesions, and mesenteric vessels were assessed and compared. The subjective image quality was assessed independently and blindly by 2 radiologists using a 5-point Likert scale.The differences of values for CTDIvol (8.64 ± 2.72 vs 11.55 ± 3.95, P < .001), ED (6.34 ± 2.24 vs 8.52 ± 3.02, P < .001), and DLP (422.6 ± 149.40 vs 568.30 ± 213.90, P < .001) were significant between group A and group B, with a reduction of 25.2%, 25.7%, and 25.7% in group A, respectively. The total iodine dosage in group A was reduced by 26.1%. The subjective image quality did not differ between the 2 groups (P > .05) and all image quality scores were greater than or equal to 3 (moderate). Fifty percent ASIR-A group images provided lower image noise, but similar or higher quantitative image quality in comparison with FBP-B group images.Compared with the conventional protocol, CTE performed at low tube voltage, low concentration of contrast agent with 50% ASIR algorithm produce a diagnostically acceptable image quality with a mean ED of 6.34 mSv and a total iodine dose reduction of 26.1%.
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Measurement of Vascular Diameter in Computed Tomography Angiography With Reduced Iodine Load. J Comput Assist Tomogr 2018; 42:919-924. [DOI: 10.1097/rct.0000000000000769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Cho SB, Baek HJ, Ryu KH, Moon JI, Choi BH, Park SE, Bae K, Jeon KN, Kim DW. Initial clinical experience with dual-layer detector spectral CT in patients with acute intracerebral haemorrhage: A single-centre pilot study. PLoS One 2017; 12:e0186024. [PMID: 29112977 PMCID: PMC5675383 DOI: 10.1371/journal.pone.0186024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 09/22/2017] [Indexed: 11/21/2022] Open
Abstract
Purpose The purpose of this study was to investigate the clinical feasibility of spectral analyses using dual-layer detector spectral computed tomography (CT) in acute intracerebral haemorrhage (ICH). Material and methods We retrospectively reviewed patients with acute ICH who underwent CT angiography on a dual-layer detector spectral CT scanner. A spectral data analysis was performed to detect contrast enhancement in or adjacent to acute ICH by using spectral image reconstructions including monoenergetic (MonoE), virtual noncontrast (VNC), and iodine overlay fusion images. We also acquired a spectral plot to assess material differentiation within lesions. Results Among the 30 patients, the most common cause of acute ICH was chronic hypertension (18/30, 60%) followed by trauma (5/30, 16.7%), brain tumour (3/30, 10%), Moyamoya disease (2/30, 6.7%), and haemorrhagic diathesis from anticoagulation therapy (2/30, 6.7%). Of 30 patients, 13 showed suboptimal iodine suppression in the subcalvarial spaces on VNC images compared with true noncontrast images. The CT angiographic spot sign within the acute ICH was detected in four patients (4/30, 13.3%). All three tumours were metastatic and included lung cancer (n = 2) and hepatocellular carcinoma (n = 1) which showed conspicuous delineation of an enhancing tumour portion in the spectral analysis. Spectral analyses allowed the discrimination of acute haemorrhage and iodine with enhanced lesion visualization on the MonoE images obtained at lower keVs (less than 70 keV) and spectral plot. Conclusions Even though the image quality of VNC is perceived to be inferior, it is feasible to evaluate acute ICH in clinical settings using dual-layer detector spectral CT. The MonoE images taken at lower keVs were useful for depicting contrast enhancing lesion, and spectral plot might be helpful for material differentiation in patients with acute ICH.
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Affiliation(s)
- Soo Buem Cho
- Department of Radiology, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - Hye Jin Baek
- Department of Radiology, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
- * E-mail:
| | - Kyeong Hwa Ryu
- Department of Radiology, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - Jin Il Moon
- Department of Radiology, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - Bo Hwa Choi
- Department of Radiology, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - Sung Eun Park
- Department of Radiology, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - Kyungsoo Bae
- Department of Radiology, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - Kyung Nyeo Jeon
- Department of Radiology, Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - Dong Wook Kim
- Department of Radiology, Busan Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea
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Nagayama Y, Nakaura T, Oda S, Utsunomiya D, Funama Y, Iyama Y, Taguchi N, Namimoto T, Yuki H, Kidoh M, Hirata K, Nakagawa M, Yamashita Y. Dual-layer DECT for multiphasic hepatic CT with 50 percent iodine load: a matched-pair comparison with a 120 kVp protocol. Eur Radiol 2017; 28:1719-1730. [PMID: 29063254 DOI: 10.1007/s00330-017-5114-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/15/2017] [Accepted: 10/02/2017] [Indexed: 01/17/2023]
Abstract
OBJECTIVES To evaluate the image quality and lesion conspicuity of virtual-monochromatic-imaging (VMI) with dual-layer DECT (DL-DECT) for reduced-iodine-load multiphasic-hepatic CT. METHODS Forty-five adults with renal dysfunction who had undergone hepatic DL-DECT with 300-mgI/kg were included. VMI (40-70-keV, DL-DECT-VMI) was generated at each enhancement phase. As controls, 45 matched patients undergoing standard 120-kVp protocol (120-kVp, 600-mgI/kg, and iterative reconstruction) were included. We compared the size-specific dose estimate (SSDE), image noise, CT attenuation, and contrast-to-noise ratio (CNR) between protocols. Two radiologists scored the image quality and lesion conspicuity. RESULTS SSDE was significantly lower in DL-DECT group (p < 0.01). Image noise of DL-DECT-VMI was almost constant at each keV (differences of ≤15%) and equivalent to or lower than of 120-kVp. As the energy decreased, CT attenuation and CNR gradually increased; the values of 55-60 keV images were almost equivalent to those of standard 120-kVp. The highest scores for overall quality and lesion conspicuity were assigned at 40-keV followed by 45 to 55-keV, all of which were similar to or better than of 120-kVp. CONCLUSIONS For multiphasic-hepatic CT with 50% iodine-load, DL-DECT-VMI at 40- to 55-keV provides equivalent or better image quality and lesion conspicuity without increasing radiation dose compared with standard 120-kVp protocol. KEY POINTS • 40-55-keV yields optimal image quality for half-iodine-load multiphasic-hepatic CT with DL-DECT. • DL-DECT protocol decreases radiation exposure compared with 120-kVp scans with iterative reconstruction. • 40-keV images maximise conspicuity of hepatocellular carcinoma especially at hepatic-arterial phase.
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Affiliation(s)
- Yasunori Nagayama
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
| | - Takeshi Nakaura
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Seitaro Oda
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Daisuke Utsunomiya
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Yoshinori Funama
- Department of Medical Physics, Faculty of Life Sciences, Kumamoto University, 4-24-1 Kuhonji, Chuo-ku, Kumamoto, 862-0976, Japan
| | - Yuji Iyama
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Narumi Taguchi
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Tomohiro Namimoto
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Hideaki Yuki
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Masafumi Kidoh
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Kenichiro Hirata
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Masataka Nakagawa
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
| | - Yasuyuki Yamashita
- Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan
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Tsang DS, Merchant TE, Merchant SE, Smith H, Yagil Y, Hua CH. Quantifying potential reduction in contrast dose with monoenergetic images synthesized from dual-layer detector spectral CT. Br J Radiol 2017; 90:20170290. [PMID: 28749176 PMCID: PMC5853359 DOI: 10.1259/bjr.20170290] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 08/06/2017] [Accepted: 07/13/2017] [Indexed: 01/14/2023] Open
Abstract
OBJECTIVE To estimate the potential dose reduction in iodinated contrast when interpreting monoenergetic images from spectral CT. METHODS 51 paediatric patients received contrast-enhanced CT simulation for radiation therapy using a single-source, dual-layer detector spectral CT. The contrast-to-noise ratios (CNRs) of blood vessels were measured relative to surrounding soft tissue. CNRs on monoenergetic 40-70 keV images were compared with polychromatic 120 kVp images. To compare with in vivo results, a phantom with iodine inserts (2-20 mg ml-1 concentration) was scanned and CNRs were calculated relative to water background. RESULTS Monoenergetic keV and body site had significant effects on CNR ratio (p < 0.0001). Across all body sites, the mean CNR ratio (monoenergetic/polychromatic CNR) was 3.3 (20th percentile [%20] 2.6), 2.4 (%20 2.1), 1.7 (%20 1.5), 1.2 (%20 1.0) for 40, 50, 60 and 70 keV images, respectively. Image noise was highest at 40 keV and lowest at 70 keV. Phantom measurements indicated that the same CNR as 120 kVp images can be achieved with a 4.0-fold lower iodine concentration on 40 keV images and 2.5-fold lower on 50 keV images. CONCLUSION 50 keV monoenergetic images provided the best balance of improved CNR on all studies (mean 2.4-fold increase in vivo) for enhancing vessels vs image noise. A 50% reduction in contrast dose on a 50 keV image should maintain comparable or better CNR as compared with polychromatic CT in over 80% of CT studies. Advances in knowledge: Use of a novel, single-source, dual-layer detector spectral CT scanner to improve visualization of contrast-enhanced blood vessels will reduce the amount of iodinated contrast required for radiation oncology treatment planning.
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Affiliation(s)
- Derek S Tsang
- Department of Radiation Oncology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Thomas E Merchant
- Department of Radiation Oncology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Sophie E Merchant
- Department of Radiation Oncology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Hanna Smith
- Department of Radiation Oncology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | | | - Chia-Ho Hua
- Department of Radiation Oncology, St. Jude Children’s Research Hospital, Memphis, TN, USA
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Hou P, Feng X, Liu J, Zhou Y, Jiang Y, Jiang X, Gao J. Iterative reconstruction in single-source dual-energy CT angiography: feasibility of low and ultra-low volume contrast medium protocols. Br J Radiol 2017; 90:20160506. [PMID: 28555508 DOI: 10.1259/bjr.20160506] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE To evaluate the feasibility of using contrast medium (CM) of low and ultra-low volumes and injection rates in aortic CT angiography (CTA) through the joint application of single-source dual-energy CT (ssDECT) and adaptive statistical iterative reconstruction (ASIR). METHODS 120 patients with known or suspected aortic dissection underwent aortic CTA and were equally divided into 3 groups. Conventional 120-kVp scan with a CM volume of 70 ml and an injection rate of 5 ml s-1 was performed on Group A. Groups B and C underwent ssDECT scan with CM volumes of 0.6 and 0.4 ml kg-1, respectively. 40% and 50% ASIR algorithms were applied for Groups B and C, respectively. A five-point grading scheme was utilized to subjectively evaluate the image quality, and the CT value and contrast-to-noise ratio were recorded as objective measures. The radiation dose was also evaluated. RESULTS Groups B and C had equivalent subjective scores and CT values as Group A, whereas they had higher or equivalent contrast-to-noise ratios. Group B had 40.1% and 30% reductions on CM volume and injection rate, respectively, than Group A. Group C further resulted in 19.2% and 22% lesser CM volume and injection rate than Group B. The average effective radiation doses for the study groups were 22.5-24.5% lower than the control group. CONCLUSION With the aid of ASIR and ssDECT for aortic CTA, it is feasible to adopt low and ultra-low CM volumes and injection rates while obtaining good quality images. Advances in knowledge: Low and ultra-low CM volumes and injection rates are feasible in CTA through the joint application of ssDECT and ASIR.
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Affiliation(s)
- Ping Hou
- 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Xiangnan Feng
- 2 Department of Statistics, The Chinese University of Hong Kong, Hong Kong, China
| | - Jie Liu
- 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Yue Zhou
- 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Yaojun Jiang
- 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Xiaochen Jiang
- 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Jianbo Gao
- 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
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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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