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Huang Y, Sun X, Ding X, Tan S, Yu Z, Shi X, Li X, Ge H. Pathological Intraplaque Hemorrhage as the Gold Standard to Assess the Efficacy of Ultrasound in Predicting Vulnerable Carotid Plaque Rupture. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2024. [PMID: 38962941 DOI: 10.1002/jum.16518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 05/27/2024] [Accepted: 06/14/2024] [Indexed: 07/05/2024]
Abstract
OBJECTIVE To assess the clinical utility of ultrasound in predicting the risk of carotid vulnerable plaque rupture using pathological intraplaque hemorrhage as the gold standard. METHODS A total of 118 patients who underwent endarterectomy due to symptomatic carotid artery stenosis were enrolled. Conventional ultrasound assessed the plaque thickness, area stenosis rate, echo, and surface morphology. Neovascularization were assessed by contrast-enhanced ultrasound (CEUS) and tracing intraplaque nonenhanced areas. According to neovascularization grade (0-4), plaques were classified as low-, intermediate-, and high risk. Fresh intraplaque hemorrhage within the pathology was adopted as the gold standard for diagnosing plaque rupture risk. Thus, we divided patients into ruptured risk and nonruptured risk groups to assess the value of crucial factors for plaque rupture risk using ultrasound. RESULTS Of the 118 patients, hypertension accounted for 71.2%, hyperlipidemia 68.6%, diabetes 52.5%, and statin history 64.4%. In the rupture risk group, diabetes, smoking, and stenosis rate were significantly higher than the nonrupture risk group (P < .001); plaque thickness ≥4 mm (P > .05); and mainly hypoechoic with irregular surface morphology (P < .001), nonenhanced areas in the plaques (P < .001), and neovascularization >grade 2 (P < .001). Compared with the low-risk group, plaque rupture risk was 7.219 times higher in the medium-risk group and 18.333 times higher in the high-risk group. The kappa value of the interobserver consistency of crucial ultrasound parameters was >0.75, and the intraclass correlation coefficient was 0.919 (P < .01). CONCLUSIONS Both conventional ultrasound and CEUS have significant clinical importance in the prediction of rupture risk in vulnerable carotid plaques, thereby enabling stroke risk stratification and the assessment of plaque rupture risk.
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Affiliation(s)
- Yaping Huang
- Department of Ultrasound, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
- Department of Ultrasound, Chuiyangliu Hospital Affiliated to Tsinghua University, Beijing, China
| | - Xinping Sun
- Department of Ultrasound, Chuiyangliu Hospital Affiliated to Tsinghua University, Beijing, China
| | - Xu Ding
- Department of Vascular Surgery, Chuiyangliu Hospital Affiliated to Tsinghua University, Beijing, China
| | - Shuping Tan
- Department of Vascular Surgery, Beijing Hospital, Beijing, China
| | - Zexing Yu
- Department of Ultrasound, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Xue Shi
- Department of Ultrasound, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Xin Li
- Department of Ultrasound, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Huiyu Ge
- Department of Ultrasound, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
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Fum WKS, Md Shah MN, Raja Aman RRA, Abd Kadir KA, Wen DW, Leong S, Tan LK. Generation of fluoroscopy-alike radiographs as alternative datasets for deep learning in interventional radiology. Phys Eng Sci Med 2023; 46:1535-1552. [PMID: 37695509 DOI: 10.1007/s13246-023-01317-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 08/03/2023] [Indexed: 09/12/2023]
Abstract
In fluoroscopy-guided interventions (FGIs), obtaining large quantities of labelled data for deep learning (DL) can be difficult. Synthetic labelled data can serve as an alternative, generated via pseudo 2D projections of CT volumetric data. However, contrasted vessels have low visibility in simple 2D projections of contrasted CT data. To overcome this, we propose an alternative method to generate fluoroscopy-like radiographs from contrasted head CT Angiography (CTA) volumetric data. The technique involves segmentation of brain tissue, bone, and contrasted vessels from CTA volumetric data, followed by an algorithm to adjust HU values, and finally, a standard ray-based projection is applied to generate the 2D image. The resulting synthetic images were compared to clinical fluoroscopy images for perceptual similarity and subject contrast measurements. Good perceptual similarity was demonstrated on vessel-enhanced synthetic images as compared to the clinical fluoroscopic images. Statistical tests of equivalence show that enhanced synthetic and clinical images have statistically equivalent mean subject contrast within 25% bounds. Furthermore, validation experiments confirmed that the proposed method for generating synthetic images improved the performance of DL models in certain regression tasks, such as localizing anatomical landmarks in clinical fluoroscopy images. Through enhanced pseudo 2D projection of CTA volume data, synthetic images with similar features to real clinical fluoroscopic images can be generated. The use of synthetic images as an alternative source for DL datasets represents a potential solution to the application of DL in FGIs procedures.
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Affiliation(s)
- Wilbur K S Fum
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
- Division of Radiological Sciences, Singapore General Hospital, Outram Road, Singapore, 169608, Singapore
| | - Mohammad Nazri Md Shah
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | | | - Khairul Azmi Abd Kadir
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - David Wei Wen
- Department of Vascular and Interventional Radiology, Singapore General Hospital, Outram Road, Singapore, 169608, Singapore
| | - Sum Leong
- Department of Vascular and Interventional Radiology, Singapore General Hospital, Outram Road, Singapore, 169608, Singapore
| | - Li Kuo Tan
- Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
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Dieckmeyer M, Sollmann N, Kupfer K, Löffler MT, Paprottka KJ, Kirschke JS, Baum T. Computed Tomography of the Head : A Systematic Review on Acquisition and Reconstruction Techniques to Reduce Radiation Dose. Clin Neuroradiol 2023; 33:591-610. [PMID: 36862232 PMCID: PMC10449676 DOI: 10.1007/s00062-023-01271-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 01/24/2023] [Indexed: 03/03/2023]
Abstract
In 1971, the first computed tomography (CT) scan was performed on a patient's brain. Clinical CT systems were introduced in 1974 and dedicated to head imaging only. New technological developments, broader availability, and the clinical success of CT led to a steady growth in examination numbers. Most frequent indications for non-contrast CT (NCCT) of the head include the assessment of ischemia and stroke, intracranial hemorrhage and trauma, while CT angiography (CTA) has become the standard for first-line cerebrovascular evaluation; however, resulting improvements in patient management and clinical outcomes come at the cost of radiation exposure, increasing the risk for secondary morbidity. Therefore, radiation dose optimization should always be part of technical advancements in CT imaging but how can the dose be optimized? What dose reduction can be achieved without compromising diagnostic value, and what is the potential of the upcoming technologies artificial intelligence and photon counting CT? In this article, we look for answers to these questions by reviewing dose reduction techniques with respect to the major clinical indications of NCCT and CTA of the head, including a brief perspective on what to expect from current and future developments in CT technology with respect to radiation dose optimization.
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Affiliation(s)
- Michael Dieckmeyer
- Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department of Diagnostic and Interventional Neuroradiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Nico Sollmann
- Department of Diagnostic and Interventional Neuroradiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- TUM-Neuroimaging Center, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- Department of Diagnostic and Interventional Radiology, University Hospital Ulm, Ulm, Germany
| | - Karina Kupfer
- Department of Diagnostic and Interventional Neuroradiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Maximilian T. Löffler
- Department of Diagnostic and Interventional Neuroradiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- Department of Diagnostic and Interventional Radiology, University Medical Center Freiburg, Freiburg im Breisgau, Germany
| | - Karolin J. Paprottka
- Department of Diagnostic and Interventional Neuroradiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Jan S. Kirschke
- Department of Diagnostic and Interventional Neuroradiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- TUM-Neuroimaging Center, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Thomas Baum
- Department of Diagnostic and Interventional Neuroradiology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
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Fernández-Gómez M, Gallo-Pineda F, Hidalgo-Barranco C, Castro-Luna G, Martínez-Sánchez P. Accuracy of Computed Tomography Angiography for Diagnosing Extracranial Mural Lesions in Patients with Acute Internal Carotid Artery Occlusion: Correlation with Digital Subtraction Angiography. J Pers Med 2023; 13:1169. [PMID: 37511782 PMCID: PMC10381416 DOI: 10.3390/jpm13071169] [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: 06/28/2023] [Revised: 07/11/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023] Open
Abstract
Extracranial carotid mural lesions (CML), caused by atherosclerosis or dissection, are frequently observed in acute internal carotid artery (ICA) occlusion, often requiring angioplasty or stenting. This study aimed to assess the diagnostic accuracy of computed tomography angiography (CTA) in differentiating extracranial CML from thromboembolic etiology in acute ICA occlusion in patients eligible for endovascular treatment. Two neuroradiologists retrospectively studied patients with apparent extracranial ICA occlusion on CTA. Patients were divided into two groups: thromboembolism and CML, based on findings from CTA and digital subtraction angiography (DSA). CTA sensitivity and specificity were calculated using DSA as the gold standard. Occlusive patterns and cervical segment widening were evaluated for atherosclerosis, dissection, and thromboembolism etiologies. CTA had a sensitivity of 84.91% (74.32-95.49%) and a specificity of 95.12% (87.31-100%) in detecting extracranial CML. Atherosclerosis was the most common cause, distinguishable with high accuracy using CTA (p < 0.001). No significant differences were found in occlusive patterns between dissection and thromboembolism (p = 0.568). Cervical segment widening was only observed in dissection cases due to mural hematoma. Conclusions: CTA accurately differentiates extracranial CML from thromboembolic etiology in acute ICA occlusion. The pattern of the occlusion and the artery widening help to establish the location and the etiology of the occlusion.
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Affiliation(s)
- Miriam Fernández-Gómez
- Interventional Neuroradiology, Torrecardenas University Hospital, University of Almería, 04009 Almería, Spain
| | - Félix Gallo-Pineda
- Interventional Neuroradiology, Torrecardenas University Hospital, University of Almería, 04009 Almería, Spain
| | - Carlos Hidalgo-Barranco
- Interventional Neuroradiology, Torrecardenas University Hospital, University of Almería, 04009 Almería, Spain
| | | | - Patricia Martínez-Sánchez
- Stroke Centre, Department of Neurology, Torrecardenas University Hospital, University of Almería, 04009 Almería, Spain
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Ren SJ, Tan QQ, Cao D, Ke NW, Liu XB, Wang X. Prognostic role and predictors of lymph node involvement in pancreatic neuroendocrine tumors. Eur J Radiol 2023; 162:110772. [PMID: 36940547 DOI: 10.1016/j.ejrad.2023.110772] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 03/05/2023] [Accepted: 03/09/2023] [Indexed: 03/17/2023]
Abstract
PURPOSE To define the prognostic role of lymph node involvement (LNI) in patients with pancreatic neuroendocrine tumors (PNETs) and identify predictors of LNI using a comprehensive multifactor analysis focusing on preoperative radiological features. METHODS This study included 236 patients with preoperative computed tomography who underwent radical surgical resection of PNETs at our hospital between 2009 and 2019. Univariate and multivariable logistic regression analyses were performed to investigate the risk factors associated with LNI and tumor recurrence. The disease-free survival (DFS) rates with and without LNI were compared. RESULTS Forty-four of the 236 patients (18.6%) had LNI. Biliopancreatic duct dilatation (odds ratio [OR], 2.295; 95% confidence interval [CI], 1.046-5.035; p = 0.038), tumor margin (OR, 2.189; 95% CI, 1.034-4.632; p = 0.041), and WHO grade (G2: OR, 2.923; 95% CI, 1.005-8.507; p = 0.049; G3: OR, 12.067; 95% CI, 3.057-47.629; p < 0.001) were independent risk factors of LNI in PNETs. Multivariable analysis showed that LNI (OR, 2.728; 95% CI, 1.070-6.954; p = 0.036), G3 (OR, 4.894; 95% CI, 1.047-22.866; p = 0.044), and biliopancreatic duct dilatation (OR, 2.895; 95% CI, 1.124-7.458; p = 0.028) were associated with PNET recurrence in patients after surgery. Patients with LNI had a significantly worse DFS than those without LNI (3-year DFS: 85.9 vs. 96.7%; p < 0.001; 5-year DFS: 65.1 vs. 93.9%; p < 0.001). CONCLUSION LNI was associated with decreased DFS. Biliopancreatic duct dilatation, irregular tumor margins, and grades G2 and G3 were independent risk factors for LNI.
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Affiliation(s)
- Shu-Jie Ren
- Department of Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Qing-Quan Tan
- Department of Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Dan Cao
- Department of Oncology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Neng-Wen Ke
- Department of Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Xu-Bao Liu
- Department of Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Xing Wang
- Department of Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China.
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Patient dose in CT angiography examinations: An institutional survey. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Li B, Ren M, Abouelfetouh MM, Guo P, Ding MX, Yang D, Wu Y, Ding Y. Optimal delay for triple-phase hepatic computed tomography using a bolus-tracking technique in cats. ANIMAL DISEASES 2022. [DOI: 10.1186/s44149-022-00038-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
AbstractThe objective of this study was to provide the characteristics of hepatic computed tomography images and optimize their transition delay with a bolus-tracking technique for triple-phase hepatic computed tomography in cats. Dynamic triple-phase computed tomography was performed in nine healthy cats. The upper third of the liver was dynamically scanned every 0.5 s for 40 s. The time density curves of the aorta and hepatic parenchyma mean enhancement were analyzed. Triple-phase hepatic computed tomography was performed three times with a bolus trigger of 200 Hounsfield units of aortic enhancement. The transition delays of the arterial, portal, and hepatic parenchymal phases were respectively 0, 5 and 60 s in the first scan; 2, 7 and 62 s in the second scan; and 4, 9 and 64 s in the third scan. All computed tomography images were evaluated by a certificated radiologist. The arterial vessels and their main branches were well enhanced at a 2 s transition delay. The contrast of the portal vein to the liver parenchyma was most obvious at a 7 s transition delay. The mean enhancement of the hepatic parenchyma peaked at a 62 s transition delay, whereas the degree of enhancement of the hepatic vasculature decreased. In this study, the recommended transition delays for the arterial, portal, and hepatic parenchymal phases were 2 s, 7 s and 62 s, respectively, after triggering at 200 Hounsfield units of aortic enhancement. This information may be helpful in diagnosing feline liver diseases and provides a key reference for the clinical implementation of CT.
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Wang Y, Chen Y, Liu P, Lv W, Wu J, Wei M, Shi D, Wu X, Liu W, Tao X, Hu H, Ma X, Yang X, Xue H, Jin Z. Clinical effectiveness of contrast medium injection protocols for 80-kV coronary and craniocervical CT angiography-a prospective multicenter observational study. Eur Radiol 2022; 32:3808-3818. [PMID: 35103828 DOI: 10.1007/s00330-021-08505-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 10/22/2021] [Accepted: 12/04/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND AND OBJECTIVE Decreasing X-ray tube voltage is an effective way to reduce radiation and contrast dose, especially in non-obese patients. The current study focuses on CTA in non-obese patients to evaluate image quality and feasibility of 80-kV acquisition protocols with varying iodine delivery rates (IDR) and contrast concentrations in routine clinical practice. METHODS A prospective observational study in patients ≥ 18 years and ≤ 90 kg referred for coronary or craniocervical CTA at 10 centers in China (ClinicalTrials.gov: NCT02840903). Patients were divided into four groups: a standard 100-kV protocol (370 mgI/ml, IDR 1.48 gI/s), and three 80-kV protocols (370 mgI/ml, IDR 1.2 gI/s; 300 mgI/ml, IDR 1.2 gI/s; 300 mgI/ml, IDR 0.96gI/s). The primary outcome was contrast opacification of target vascular segments. Secondary outcomes were image quality (contrast-to-noise ratio, signal-to-noise ratio, visual image quality, and diagnostic confidence assessment), radiation, and iodine dose. RESULTS From July 2016 to July 2017, 1213 patients were enrolled: 614 coronary and 599 craniocervical CTA. The mean contrast opacification was ≥ 300 HU for 80-kV 1.2 gI/s IDR scanned segments; IDR 0.96 gI/s led to lower opacification. Image quality and diagnostic confidence were fair to excellent (≥ 98% of images), despite lower contrast-to-noise ratios and signal-to-noise ratios in 80-kV images. Compared to the standard protocol, 80-kV protocols led to 44-52% radiation dose reductions (p < 0.001) and 19% iodine dose reductions (p < 0.001). CONCLUSION Eighty-kilovolt 1.2 gI/s IDR protocols can be recommended for coronary and craniocervical CTA in non-obese patients, reducing radiation and iodine dose without compromising image quality. KEY POINTS • Using low-voltage scanning CTA protocols, in which tube voltage and iodine delivery rate are reduced proportionally (voltage: 80 kV, IDR: 1.2 gI/s), reduces radiation and contrast dose without compromising image quality in routine clinical practice. • Reducing iodine delivery rate beyond direct proportionality to tube voltage is not beneficial.
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Affiliation(s)
- Yining Wang
- Peking Union Medical College Hospital, Shuaifuyan Wangfujing District, Beijing, 100730, China
| | - Yu Chen
- Peking Union Medical College Hospital, Shuaifuyan Wangfujing District, Beijing, 100730, China
| | - Peijun Liu
- Peking Union Medical College Hospital, Shuaifuyan Wangfujing District, Beijing, 100730, China
| | - Wan Lv
- The First People's Hospital of Yulin, # 495, JiaoYu Central Road, Yulin, 537000, Guangxi, China
| | - Jianlin Wu
- Affiliated Zhongshan Hospital of Dalian University, # 6, Jiefang Road Zhongshan District, Dalian, 116001, Liaoning, China
| | - Mengqi Wei
- The First Affiliated Hospital of Air Force Medical University, # 15 Changle West Road, Xian, 710032, Shanxi, China
| | - Dapeng Shi
- Henan Provincial People's Hospital, # 7, Weiwu Road, Zhengzhou, 450000, Henan, China
| | - Xianheng Wu
- The Second People's Hospital of Shantou, # 28, Waimalu Road, Shantou, 515031, Guangdong, China
| | - Wenya Liu
- The First Affiliated Hospital of Xinjiang Medical University, # 137, Liyushan South Road, Urumqi, 830054, Xinjiang, China
| | - Xiaofeng Tao
- Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, # 639, Zaoju Road, Shanghai, 200011, China
| | - Hongjie Hu
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 Qinchun East Road, Hangzhou, 310016, Zhejiang, China
| | - Xiangxing Ma
- Qilu Hospital of Shandong University (Qingdao), North District, # 758, Hefei Road, Qingdao, 266035, Shandong, China
| | - Xiaozheng Yang
- Medical Affairs, Bayer Healthcare Co. Ltd, Dongshanhuan Central Road, Beijing, 100010, China
| | - Huadan Xue
- Peking Union Medical College Hospital, Shuaifuyan Wangfujing District, Beijing, 100730, China
| | - Zhengyu Jin
- Peking Union Medical College Hospital, Shuaifuyan Wangfujing District, Beijing, 100730, China.
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Bathla G, Priya S, Samaniego E, Deo SK, Fain NH, Soni N, Ward C, Derdeyn CP. Cerebral computed tomographic angiography using third-generation reconstruction algorithm provides improved image quality with lower contrast and radiation dose. Neuroradiology 2020; 62:965-970. [PMID: 32277245 DOI: 10.1007/s00234-020-02406-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 03/13/2020] [Indexed: 02/03/2023]
Abstract
PURPOSE We hypothesized that cerebral CT angiogram performed using third-generation reconstruction algorithm and lower contrast dose-low-kVp technique (LD-CTA) will provide better image quality when compared with regular contrast dose CTA at 120 kVp using a sinogram-affirmed iterative reconstruction algorithm (ND-CTA). METHODS Retrospective imaging review of 100 consecutive patients (50 each in LD- and ND-CTA groups). Two readers independently assessed the subjective image quality across multiple vascular segments on a Likert-like scale. Differences in contrast dose, CT dose index (CTDI), and dose length product (DLP) were compared using Mann-Whitney U test. Fisher's exact test was used to compare subjective image quality. Similarly, contrast- and signal-to-noise ratios (CNR and SNR) were compared in the mid-M1 MCA vessels bilaterally and the mid-basilar artery using Mann-Whitney U test. Interclass correlation coefficient (ICC) was calculated for the SNR/CNR values. RESULTS Both observers showed excellent correlation in subjective image quality (mean percentage agreement of 95.2% for group 1 versus 89.2% for group 2). LD-CTA group showed better SNR and CNR (p < 0.0001) for both MCA vessels and the mid-basilar artery. Interclass correlation coefficient showed moderate correlation (0.51-0.63) between readers. LD-CTA group also used lower contrast (49 cc versus 97 cc in ND-CTA) and had lower radiation exposure (DLP/CTDI for both groups 268.3/80.7 vs 519.5/36.08, both < 0.0001). CONCLUSION Next-generation reconstruction algorithm and low-kV scanning significantly improved image quality on cerebral CTA images despite lower contrast dose and, in addition, have lower radiation exposure.
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Affiliation(s)
- Girish Bathla
- Department of Radiology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA.
| | - Sarv Priya
- Department of Radiology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA
| | - Edgar Samaniego
- Department of Radiology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
| | - Simmi K Deo
- Department of Radiology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA
| | - Nicholas H Fain
- Department of Radiology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA
| | - Neetu Soni
- Department of Radiology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA
| | - Caitlin Ward
- Department of Biostatistics, University of Iowa, Iowa City, IA, USA
| | - Colin P Derdeyn
- Department of Radiology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA
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Ren Z, Zhang X, Hu Z, Li D, Liu Z, Wei D, Jia Y, Yu N, Yu Y, Lei Y, Chen X, Guo C, Ren Z, He T. Reducing Radiation Dose and Improving Image Quality in CT Portal Venography Using 80 kV and Adaptive Statistical Iterative Reconstruction-V in Slender Patients. Acad Radiol 2020; 27:233-243. [PMID: 31031186 DOI: 10.1016/j.acra.2019.02.022] [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: 01/16/2019] [Revised: 02/26/2019] [Accepted: 02/27/2019] [Indexed: 01/23/2023]
Abstract
OBJECTIVE To explore the feasibility of reducing radiation dose and improving image quality in CT portal venography (CTPV) using 80 kV and adaptive statistical iterative reconstruction-V(ASIR-V) in slender patients in comparison with conventional protocol using 120 kV and ASIR. METHODS Sixty slender patients for enhanced abdominal CT scanning were randomly divided into group A and group B. Group A used the conventional 120 kV tube voltage, 600 mgI/kg contrast dose and reconstructed with the recommended 40% ASIR. Group B used 80 kV tube voltage, 350 mgI/kg contrast dose and reconstructed with ASIR-V from 40% to 100% with 10% interval. The CT values and standard deviation (SD) values of the main portal vein, left branch, and right branch of portal vein, liver, and erector spinae at the same level were measured to calculate the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The image quality was subjectively scored by two experienced radiologists blindly using a 5-point criterion. The contrast dose, volumetric CT dose index, and dose length product were recorded in both groups and the effective dose was calculated. RESULTS There was no significant difference in general data between the two groups (p > 0.05), the effective dose and contrast dose in group B were reduced by 63.3% (p < 0.001) and 39.7% (p < 0.001), respectively compared with group A. With the percentage of ASIR-V increased in group B, the CT values showed no significant difference, while the SD values gradually decreased and SNR values and CNR values increased accordingly. Compared with group A, group B demonstrated similar CT values (p > 0.05), while the SD values with 80% ASIR-V to 100% ASIR-V were significantly lower than those of 40% ASIR (p < 0.001), and the SNR values and CNR values with 70% ASIR-V to 100% ASIR-V were significantly higher than those of 40% ASIR (p < 0.001). The subjective image quality scores by the two radiologists had excellent consistency (kappa value>0.75, p < 0.001), and the final subjective image quality scores and the subjective scores in each of the 5 scoring categories with 60% ASIR-V to 100% ASIR-V were all significantly higher than those of 40% ASIR, and 80% ASIR-V obtained the highest subjective score among different reconstructions. CONCLUSION In CTPV, the application of 80 kV and ASIR-V reconstruction in slender patients can significantly reduce radiation dose (by 63.3%) and contrast agent dose (by 39.7%). Compared with the recommended 40% ASIR using 120 kV, ASIR-V with 80% to 100% percentages can further improve image quality and with 80% ASIR-V being the best reconstruction algorithm. ADVANCES IN KNOWLEDGE CTPV with 80 kV and ASIR-V algorithm in slender patients can significantly reduce radiation dose and contrast agent dose as well as improve image quality, compared with the conventional 120 kV protocol using 40% ASIR.
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Tube Current Reduction in CT Angiography: How Low Can We Go in Imaging of Patients With Suspected Acute Stroke? AJR Am J Roentgenol 2019; 213:410-416. [DOI: 10.2214/ajr.18.20954] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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12
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Eller A, Wiesmüller M, Wüst W, Heiss R, Kopp M, Saake M, Brand M, Uder M, May MM. Carotid CTA at the Lowest Tube Voltage (70 kV) in Comparison with Automated Tube Voltage Adaption. AJNR Am J Neuroradiol 2019; 40:1374-1382. [PMID: 31296525 DOI: 10.3174/ajnr.a6108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 05/26/2019] [Indexed: 12/28/2022]
Abstract
BACKGROUND AND PURPOSE CTA is the imaging modality of choice in many institutions for the evaluation of the supraaortic vessels, but radiation exposure remains a matter of concern. Our aim was to evaluate a 70-kV protocol for CT angiography of the carotid arteries with respect to image quality and radiation exposure compared with automated tube voltage adaption. MATERIALS AND METHODS A total of 90 consecutive patients were included in this prospective study and randomized to the study group (n = 45, 70 kV) or control group (n = 45, automated tube voltage adaptation). Volume CT dose indices and dose-length products were recorded in the examination protocol. Image quality was assessed as arterial vessel contrast, signal-to-noise ratio, contrast-to-noise ratio, and contrast-to-noise ratio in reference to the radiation dose. Subjective overall image-quality analysis, image-artifact analysis, and diagnostic evaluation were performed by 2 observers by using a 4-point Likert scale. RESULTS Radiation exposure was significantly lower in the study group (volume CT dose index reduced by 22%, dose-length product reduction by 20%; each P < .001). Contrast (P = .15), SNR (P = .4), and contrast-to-noise ratio (P = .5) did not show significant differences between the groups. The contrast-to-noise ratio in reference to the radiation dose was not significantly increased using the study protocol (P = .2). Subjective image quality and visualization of pathologic findings did not differ significantly between the groups. CONCLUSIONS Carotid CTA using the lowest available voltage (70 kV) is feasible at very-low-dose levels, while overall image quality is comparable with protocols using automated tube voltage selection.
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Affiliation(s)
- A Eller
- From the Department of Radiology (A.E., M.W., W.W., R.H., M.K., M.S., M.B., M.U., M.M.M.), University Hospital Erlangen, Erlangen, Germany
| | - M Wiesmüller
- From the Department of Radiology (A.E., M.W., W.W., R.H., M.K., M.S., M.B., M.U., M.M.M.), University Hospital Erlangen, Erlangen, Germany
| | - W Wüst
- From the Department of Radiology (A.E., M.W., W.W., R.H., M.K., M.S., M.B., M.U., M.M.M.), University Hospital Erlangen, Erlangen, Germany
| | - R Heiss
- From the Department of Radiology (A.E., M.W., W.W., R.H., M.K., M.S., M.B., M.U., M.M.M.), University Hospital Erlangen, Erlangen, Germany
| | - M Kopp
- From the Department of Radiology (A.E., M.W., W.W., R.H., M.K., M.S., M.B., M.U., M.M.M.), University Hospital Erlangen, Erlangen, Germany
| | - M Saake
- From the Department of Radiology (A.E., M.W., W.W., R.H., M.K., M.S., M.B., M.U., M.M.M.), University Hospital Erlangen, Erlangen, Germany
| | - M Brand
- From the Department of Radiology (A.E., M.W., W.W., R.H., M.K., M.S., M.B., M.U., M.M.M.), University Hospital Erlangen, Erlangen, Germany
| | - M Uder
- From the Department of Radiology (A.E., M.W., W.W., R.H., M.K., M.S., M.B., M.U., M.M.M.), University Hospital Erlangen, Erlangen, Germany
- Imaging Science Institute (M.U., M.M.M.), Erlangen, Germany
| | - M M May
- From the Department of Radiology (A.E., M.W., W.W., R.H., M.K., M.S., M.B., M.U., M.M.M.), University Hospital Erlangen, Erlangen, Germany
- Imaging Science Institute (M.U., M.M.M.), Erlangen, Germany
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13
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Asayama Y, Nishie A, Ishigami K, Ushijima Y, Kakihara D, Fujita N, Morita K, Ishimatsu K, Takao S, Honda H. Image quality and radiation dose of renal perfusion CT with low-dose contrast agent: a comparison with conventional CT using a 320-row system. Clin Radiol 2019; 74:650.e13-650.e18. [DOI: 10.1016/j.crad.2019.03.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 03/20/2019] [Indexed: 11/28/2022]
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14
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Submillisievert CT angiography for carotid arteries using wide array CT scanner and latest iterative reconstruction algorithm in comparison with previous generations technologies: Feasibility and diagnostic accuracy. J Cardiovasc Comput Tomogr 2019; 13:41-47. [PMID: 30639115 DOI: 10.1016/j.jcct.2019.01.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 11/05/2018] [Accepted: 01/03/2019] [Indexed: 02/06/2023]
Abstract
OBJECTIVES To assess evaluability and diagnostic accuracy of a low dose CT angiography (CTA) protocol for carotid arteries using latest Iterative Reconstruction (IR) algorithm in comparison with standard 100 kVp protocol using previous generation CT and IR. MATERIALS AND METHODS 105 patients, referred for CTA of the carotid arteries were prospectively enrolled in our study and underwent CTA with 80 kVp and latest IR algorithm (group 1). Data were retrospectively compared with 100 consecutive patients with similar examination indications that had previously undergone CTA of carotid arteries with a standard 100 kVp protocol and a first generation IR algorithm (group 2). Image quality was evaluated with a 4-point Likert-scale. For each exam CT number, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) at level of common carotid artery (CCA), internal carotid artery (ICA) and at level of Circle of Willis and Effective Dose (ED) were evaluated. 62 Group 1 patients underwent a clinically indicated DSA and results were compared with CTA. RESULTS No exams reported as not diagnostic. The overall mean CT number value of all arterial segments was above 450 HU in both groups. Significant lower noise, and higher SNR and CNR values were found in group 1 in comparison with group 2 despite the use of 80 kVp. In 62-group 1 patients studied by DSA, CTA showed in a segment-based analysis a sensitivity, negative predictive value and accuracy of 100%, 100% and 99% respectively. Mean ED in group 1 was 0.54 ± 0.1 mSv with a dose reduction up to 86%. CONCLUSIONS CTA for carotid arteries using latest IR algorithm allows to perform exams with submillisievert radiation exposure maintaining good image quality, overall evaluability and diagnostic accuracy.
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15
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Tse JJ, Dunmore-Buyze J, Drangova M, Holdsworth DW. Dual-energy computed tomography using a gantry-based preclinical cone-beam microcomputed tomography scanner. J Med Imaging (Bellingham) 2018; 5:033503. [PMID: 30155511 PMCID: PMC6103383 DOI: 10.1117/1.jmi.5.3.033503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Accepted: 07/30/2018] [Indexed: 11/14/2022] Open
Abstract
Dual-energy microcomputed tomography (DECT) can provide quantitative information about specific materials of interest, facilitating automated segmentation, and visualization of complex three-dimensional tissues. It is possible to implement DECT on currently available preclinical gantry-based cone-beam micro-CT scanners; however, optimal decomposition image quality requires customized spectral shaping (through added filtration), optimized acquisition protocols, and elimination of misregistration artifacts. We present a method for the fabrication of customized x-ray filters-in both shape and elemental composition-needed for spectral shaping. Fiducial markers, integrated within the sample holder, were used to ensure accurate co-registration between sequential low- and high-energy image volumes. The entire acquisition process was automated through the use of a motorized filter-exchange mechanism. We describe the design, implementation, and evaluation of a DECT system on a gantry-based-preclinical cone-beam micro-CT scanner.
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Affiliation(s)
- Justin J Tse
- Western University, Bone and Joint Institute, Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.,Western University, Bone and Joint Institute, Departments of Medical Biophysics and Medical Imaging, London, Ontario, Canada
| | - Joy Dunmore-Buyze
- Western University, Bone and Joint Institute, Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada
| | - Maria Drangova
- Western University, Bone and Joint Institute, Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.,Western University, Bone and Joint Institute, Departments of Medical Biophysics and Medical Imaging, London, Ontario, Canada
| | - David W Holdsworth
- Western University, Bone and Joint Institute, Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.,Western University, Bone and Joint Institute, Departments of Medical Biophysics and Medical Imaging, London, Ontario, Canada.,Western University, Bone and Joint Institute, Department of Surgery, London, Ontario, Canada
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Zhao L, Li F, Zhang Z, Zhang Z, Jiang Y, Wang X, Gu J, Li D. Assessment of an advanced virtual monoenergetic reconstruction technique in cerebral and cervical angiography with third-generation dual-source CT: Feasibility of using low-concentration contrast medium. Eur Radiol 2018; 28:4379-4388. [PMID: 29654560 DOI: 10.1007/s00330-018-5407-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 02/13/2018] [Accepted: 02/22/2018] [Indexed: 12/26/2022]
Abstract
OBJECTIVES To investigate the feasibility of low-concentration contrast media (LC-CM) in cerebral and cervical dual-energy CT angiography (DE-CTA) using an advanced monoenergetic (Mono+) reconstruction technique. METHODS Sixty-five consecutive patients prospectively selected to undergo cerebral and cervical DE-CTA were randomised into two groups: 32 patients (63.7 ± 9.7 years) in the high-concentration contrast medium (HC-CM) group with iopromide 370 and 33 patients (60.7 ± 10.8 years) in the low-concentration contrast medium (LC-CM) group with iodixanol 270. Traditional monoenergetic (Mono) and Mono+ images from 40 to 100 keV levels (at 10-keV intervals) and the standard mixed (Mixed, 120 kVp equivalent) images were reconstructed. Subjective image quality parameters included the contrast-to-noise ratio (CNR) and objective image quality parameters were evaluated and compared between the two groups. RESULTS The 40-keV Mono+ images in the LC-CM group showed comparable objective CNR (common carotid arteries: 83.7 ± 24.5 vs. 78.1 ± 23.2; internal carotid arteries: 82.2 ± 26.8 vs. 76.8 ± 24.1; middle cerebral arteries: 72.5 ± 24.6 vs. 70.6 ± 19.2; all p > 0.05) and subjective image scores (3.95 ± 0.19 vs. 3.83 ± 0.35; p > 0.05) compared with Mixed images in the HC-CM group. CONCLUSION The Mono+ reconstruction technique could reduce the concentration of iodinated CM in the diagnosis of cerebral and cervical angiography. KEY POINTS • Mono+ shows decreased noise and superior CNR compared with Mono. • The 40-keV Mono+ images show the highest CNR in the LC-CM group. • The Mono+ reconstruction technique could reduce the concentration of iodinated CM.
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Affiliation(s)
- Lu Zhao
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Fengtan Li
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Zewei Zhang
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Zhang Zhang
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Yingjian Jiang
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Xinyu Wang
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Jun Gu
- Siemens Healthineers, Beijing, 100102, China
| | - Dong Li
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, 300052, China.
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Leithner D, Wichmann JL, Mahmoudi S, Martin SS, Albrecht MH, Vogl TJ, Scholtz JE. Diagnostic yield of 90-kVp low-tube-voltage carotid and intracerebral CT-angiography: effects on radiation dose, image quality and diagnostic performance for the detection of carotid stenosis. Br J Radiol 2018; 91:20170927. [PMID: 29493282 DOI: 10.1259/bjr.20170927] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE To investigate the impact of low-tube-voltage 90-kVp acquisition combined with advanced modeled iterative reconstruction algorithm (Admire) on radiation exposure, image quality, artifacts, and assessment of stenosis in carotid and intracranial CT angiography (CTA). METHODS Dual-energy CTA studies of 43 patients performed on a third-generation 192-slice dual-source CT were retrospectively evaluated. Intraindividual comparison of 90-kVp and linearly blended 120-kVp equivalent image series (M_0.6, 60% 90-kVp, 40% Sn-150-kVp) was performed. Contrast-to-noise and signal-to-noise ratios of common carotid artery, internal carotid artery, middle cerebral artery, and basilar artery were calculated. Qualitative image analysis included evaluation of artifacts and suitability for angiographical assessment at shoulder level, carotid bifurcation, siphon, and intracranial by three independent radiologists. Detection and quantification of carotid stenosis were performed. Radiation dose was expressed as dose-length product (DLP). RESULTS Contrast-to-noise values of all arteries were significantly increased in 90-kVp compared to M_0.6 (p < 0.001). Suitability for angiographical evaluation was rated excellent with low artifacts for all levels in both image series. Both 90-kVp and M_0.6 showed excellent accordance for detection and grading of carotid stenosis with almost perfect interobserver agreement (carotid stenoses in 32 of 129 segments; intraclass correlation coefficient, 0.94). dose-length product was reduced by 40.3% in 90-kVp (110.6 ± 32.1 vs 185.4 ± 47.5 mGy·cm, p < 0.001). CONCLUSION 90-kVp carotid and intracranial CTA with Admire provides increased quantitative and similarly good qualitative image quality, while reducing radiation exposure substantially compared to M_0.6. Diagnostic performance for arterial stenosis detection and quantification remained excellent. Advances in knowledge: 90-kVp carotid and intracranial CTA with an advanced iterative reconstruction algorithm results in excellent image quality and reduction of radiation exposure without limiting diagnostic performance.
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Affiliation(s)
- Doris Leithner
- 1 Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt , Frankfurt , Germany
| | - Julian L Wichmann
- 1 Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt , Frankfurt , Germany
| | - Scherwin Mahmoudi
- 1 Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt , Frankfurt , Germany
| | - Simon S Martin
- 1 Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt , Frankfurt , Germany
| | - Moritz H Albrecht
- 1 Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt , Frankfurt , Germany
| | - Thomas J Vogl
- 1 Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt , Frankfurt , Germany
| | - Jan-Erik Scholtz
- 1 Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt , Frankfurt , Germany.,2 Division of Radiology, Massachusetts General Hospital, Harvard Medical School , Boston, MA , USA
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18
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Cai W, Hu C, Hu S, Wang X, Gong J, Zhang W, Shi D, Cheng B. Feasibility study of iterative model reconstruction combined with low tube voltage, low iodine load, and low iodine delivery rate in craniocervical CT angiography. Clin Radiol 2017; 73:217.e1-217.e6. [PMID: 29066028 DOI: 10.1016/j.crad.2017.09.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 05/18/2017] [Accepted: 09/20/2017] [Indexed: 12/11/2022]
Abstract
AIM To investigate the feasibility of iterative model reconstruction (IMR) combined with low tube voltage, low iodine load, and low iodine deliver rate in craniocervical computed tomography angiography (CTA). MATERIALS AND METHODS Sixty patients were randomly divided into two groups (n=30 for each): group A: 120 kVp, 50 ml of iopromide at a flow rate of 5 ml/s; filtered back projection (FBP) reconstruction; group B: 80 kVp, 30 ml of iohexol at 4.5 ml/s; hybrid iterative reconstruction (HIR) for group B1 and IMR for group B2. CT attenuation values, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), subjective image quality, effective dose (ED), iodine load, and iodine delivery rate (IDR) were compared. RESULTS CT attenuation values of the arteries were higher in groups B1 and B2 than group A. The SNR and CNR were higher, while image noise was lower, for group B2 compared with groups B1 and A. The best subjective image quality was obtained with group B2. ED, iodine load, and IDR reduction of 69.6%, 51.4%, 27%, respectively, was obtained in group B compared with group A. CONCLUSION IMR combined with 80 kVp and 30 ml of iohexol at a flow rate of 4.5 ml/s for craniocervical CTA can reduce ED, iodine load, and IDR, while improving image quality.
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Affiliation(s)
- W Cai
- Department of Radiology, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China; Department of Radiology, Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - C Hu
- Department of Radiology, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China.
| | - S Hu
- Department of Radiology, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - X Wang
- Department of Radiology, First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - J Gong
- Department of Radiology, Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - W Zhang
- Department of Radiology, Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - D Shi
- Department of Radiology, Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - B Cheng
- Department of Radiology, West China Second University Hospital of Sichuan University, Chengdu, Sichuan, China
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