1
|
Hadjiabdolhamid N, Zhao Y, Hubbard L, Molloi S. Reproducibility of a single-volume dynamic CT myocardial blood flow measurement technique: validation in a swine model. Eur Radiol Exp 2024; 8:91. [PMID: 39143412 PMCID: PMC11324639 DOI: 10.1186/s41747-024-00498-2] [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: 04/08/2024] [Accepted: 07/15/2024] [Indexed: 08/16/2024] Open
Abstract
BACKGROUND We prospectively assessed the reproducibility of a novel low-dose single-volume dynamic computed tomography (CT) myocardial blood flow measurement technique. METHODS Thirty-four pairs of measurements were made under rest and stress conditions in 13 swine (54.3 ± 12.3 kg). One or two acquisition pairs were acquired in each animal with a 10-min delay between each pair. Contrast (370 mgI/mL; 0.5 mL/kg) and a diluted contrast/saline chaser (0.5 mL/kg; 30:70 contrast/saline) were injected peripherally at 5 mL/s, followed by bolus tracking and acquisition of a single volume scan (100 kVp; 200 mA) with a 320-slice CT scanner. Bolus tracking and single volume scan data were used to derive perfusion in mL/min/g using a first-pass analysis model; the coronary perfusion territories of the left anterior descending (LAD), left circumflex (LCx), and right coronary artery (RCA) were automatically assigned using a previously validated minimum-cost path technique. The reproducibility of CT myocardial perfusion measurement within the LAD, LCx, RCA, and the whole myocardium was assessed via regression analysis. The average CT dose index (CTDI) of perfusion measurement was recorded. RESULTS The repeated first (Pmyo1) and second (Pmyo2) single-volume CT perfusion measurements were related by Pmyo2 = 1.01Pmyo1 - 0.03(ρ = 0.96; RMSE = 0.08 mL/min/g; RMSE = 0.07 mL/min/g) for the whole myocardium, and by Preg2 = 0.86Preg1 + 0.13(ρ = 0.87; RMSE = 0.31 mL/min/g; RMSE = 0.29 mL/min/g) for the LAD, LCx, and RCA perfusion territories. The average CTDI of the single-volume CT perfusion measurement was 10.5 mGy. CONCLUSION The single-volume CT blood flow measurement technique provides reproducible low-dose myocardial perfusion measurement using only bolus tracking data and a single whole-heart volume scan. RELEVANCE STATEMENT The single-volume CT blood flow measurement technique is a noninvasive tool that reproducibly measures myocardial perfusion and provides coronary CT angiograms, allowing for simultaneous anatomic-physiologic assessment of myocardial ischemia. KEY POINTS A low-dose single-volume dynamic CT myocardial blood flow measurement technique is reproducible. Motion misregistration artifacts are eliminated using a single-volume CT perfusion technique. This technique enables combined anatomic-physiologic assessment of coronary artery disease.
Collapse
Affiliation(s)
- Negin Hadjiabdolhamid
- Department of Radiological Sciences, University of California, Irvine, Irvine, CA, 92697, USA
| | - Yixiao Zhao
- Department of Radiological Sciences, University of California, Irvine, Irvine, CA, 92697, USA
| | - Logan Hubbard
- Department of Radiological Sciences, University of California, Irvine, Irvine, CA, 92697, USA
| | - Sabee Molloi
- Department of Radiological Sciences, University of California, Irvine, Irvine, CA, 92697, USA.
| |
Collapse
|
2
|
Zuo L, Tian Z, Zhou B, Hou M, Chen Y, Han P, Ma C, Wu X, Yu D. Perivascular fat attenuation index value and plaque volume increased in non-target lesions of coronary arteries after stenting. Eur Radiol 2024; 34:4233-4242. [PMID: 38057594 DOI: 10.1007/s00330-023-10468-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 09/09/2023] [Accepted: 10/16/2023] [Indexed: 12/08/2023]
Abstract
BACKGROUND Progression of non-target lesions (NTLs) after stenting has been reported and is associated with the triggering of an inflammatory response. The perivascular fat attenuation index (FAI) may be used as a novel imaging biomarker for the direct quantification of coronary inflammation. OBJECTIVES To investigate whether FAI values can help identify changes in inflammation status in patients undergoing stent implantation, especially in NTLs. METHODS Patients who underwent pre- and post-stenting coronary computed tomography angiography (CCTA) examination between January 2015 and February 2021 were consecutively enrolled. The pre- and post-stenting FAIs of the full coronary arteries were compared in both the non- and stent-implanted coronary arteries. Moreover, local FAI values were measured and compared between the NTLs and target lesions in the stent implantations. We also compared changes in plaque type and volume in NTLs before and after stenting. RESULTS A total of 89 patients (mean age 61 years; male 59) were enrolled. The perivascular FAI values in the full coronary arteries decreased after stenting in both the non- and stent-implanted coronary arteries, similar to those in the target lesions. Conversely, the perivascular FAI values in the NTLs increased after stenting (p < 0.05). In addition, the plaque volumes significantly increased in the NTLs after stenting, regardless of whether they were non-calcified, mixed, or calcified (p < 0.05). CONCLUSION Perivascular FAI values and plaque volumes increased in the NTLs after stenting. Perivascular FAI can be a promising imaging biomarker for monitoring coronary inflammation after stenting and facilitate long-term monitoring in clinical settings. CLINICAL RELEVANCE STATEMENT Perivascular fat attenuation index, a non-invasive imaging biomarker, may help identify coronary arteries with high inflammation in non-target lesions and facilitate long-term monitoring, potentially providing an opportunity for more targeted treatment. KEY POINTS • Perivascular fat attenuation index (FAI) values and plaque volumes increased in the non-target lesions (NTLs) after stenting, suggesting potential focal inflammation progression after stenting. However, stenting along with anti-inflammatory treatment ameliorated inflammation in the full coronary arteries. • Perivascular FAI, a non-invasive imaging biomarker, may help identify coronary arteries with high inflammation in NTLs and facilitate long-term monitoring, potentially providing an opportunity for more targeted treatment.
Collapse
Affiliation(s)
- Liping Zuo
- Department of Radiology, Qilu Hospital, Shandong University, Jinan, 250012, Shandong, China
| | - Ziyu Tian
- Department of Radiology, Qilu Hospital, Shandong University, Jinan, 250012, Shandong, China
| | - Binbin Zhou
- Department of Radiology, Qilu Hospital, Shandong University, Jinan, 250012, Shandong, China
| | - Mingyuan Hou
- Department of Radiology, Qilu Hospital, Shandong University, Jinan, 250012, Shandong, China
| | - Yinghui Chen
- Department of Radiology, Qilu Hospital, Shandong University, Jinan, 250012, Shandong, China
| | - Pei Han
- Department of Radiology, Qilu Hospital, Shandong University, Jinan, 250012, Shandong, China
| | - Chune Ma
- ShuKun (BeiJing) Technology Co., Ltd., Beijing, 100029, China
| | - Xuan Wu
- Shandong Superlink Intelligent Technology Co., Ltd., Jinan, 250000, Shandong, China
| | - Dexin Yu
- Department of Radiology, Qilu Hospital, Shandong University, Jinan, 250012, Shandong, China.
| |
Collapse
|
3
|
Gnasso C, Vecsey-Nagy M, Schoepf UJ, Stock J, Zsarnoczay E, Pinos D, Tremamunno G, Giovagnoli V, Seidensticker P, Emrich T, Varga-Szemes A. Evaluation of a Tube Voltage-Based Contrast Media Adaptation in Coronary Computed Tomography Angiography Using Personalized Triphasic Injection Protocols: A Matched Case-Control Study. Acad Radiol 2024:S1076-6332(24)00256-3. [PMID: 38734579 DOI: 10.1016/j.acra.2024.04.039] [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: 02/14/2024] [Revised: 04/16/2024] [Accepted: 04/22/2024] [Indexed: 05/13/2024]
Abstract
RATIONALE AND OBJECTIVES Coronary CT angiography (CCTA) has recently been established as a first-line test in patients with suspected coronary artery disease (CAD). Due to the increased use of CCTA, strategies to reduce radiation and contrast medium (CM) exposure are of high importance. The aim of this study was to evaluate the performance of automated tube voltage selection (ATVS)-adapted CM injection protocol for CCTA compared to a clinically established triphasic injection protocol in terms of image quality, radiation exposure, and CM administration MATERIAL AND METHODS: Patients undergoing clinically indicated CCTA were prospectively enrolled from July 2021 to July 2023. Patients underwent CCTA using a modified triphasic CM injection protocol tailored to the tube voltage by the ATVS algorithm, in a range of 70 to 130 kV with a 10 kV interval. The injection protocol consisted of two phases of mixed CM and saline boluses with different proportions to assure a voltage-specific iodine delivery rate, followed by a third phase of saline flush. This cohort was compared to a control group identified retrospectively and scanned on the same CT system but with a standard triphasic CM protocol. Radiation and contrast dose, subjective and objective image quality (contrast-to-noise-ratio [CNR] and signal-to-noise-ratio [SNR]) were compared between the two groups. RESULTS The final population consisted of 120 prospective patients matched with 120 retrospective controls, with 20 patients in each kV group. The 120 kV group was excluded from the statistical analysis due to insufficient sample size. A significant CM reduction was achieved in the prospective group overall (46.0 [IQR 37.0-52.0] vs. 51.3 [IQR 40.1-73.0] mL, p < 0.001) and at all kV levels too (all pairwise p < 0.001). There were no significant differences in radiation dose (6.13 ± 4.88 vs. 5.97 ± 5.51 mSv, p = 0.81), subjective image quality (median score of 4 [3-5] vs. 4 [3-5], p = 0.40), CNR, and SNR in the aorta and the left anterior descending coronary artery (all p > 0.05). CONCLUSION ATVS-adapted CM injection protocol allows for diagnostic quality CCTA with reduced CM volume while maintaining similar radiation exposure, subjective and objective image quality.
Collapse
Affiliation(s)
- Chiara Gnasso
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, South Carolina 29425, USA; Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, Milan, Italy
| | - Milan Vecsey-Nagy
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, South Carolina 29425, USA; Heart and Vascular Centre, Semmelweis University, Varosmajor utca 68, Budapest 1122, Hungary
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, South Carolina 29425, USA.
| | - Jonathan Stock
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, South Carolina 29425, USA; Paracelsus Medical University, Nuremberg, Prof.-Ernst-Nathan-Strasse 1, 90419 Nuremberg, Germany
| | - Emese Zsarnoczay
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, South Carolina 29425, USA; MTA-SE Cardiovascular Imaging Research Group, Department of Radiology, Medical Imaging Centre, Semmelweis University, H-1082 Budapest, Üllői út 78, Budapest, Hungary
| | - Daniel Pinos
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, South Carolina 29425, USA
| | - Giuseppe Tremamunno
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, South Carolina 29425, USA; Radiology Unit, Department of Surgical and Medical Sciences and Translational Medicine, Sapienza University of Rome - Sant'Andrea University Hospital, Via di Grottarossa, 1035-1039, 00189, Rome, Italy
| | - Vincent Giovagnoli
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, South Carolina 29425, USA
| | - Peter Seidensticker
- Global Medical Affairs Radiology, Bayer US LLC, Pittsburgh, Pennsylvania, USA
| | - Tilman Emrich
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, South Carolina 29425, USA; Department of Diagnostic and Interventional Radiology, University Medical Center of Johannes Gutenberg University, Langenbeckstr. 1, Mainz 55131, Germany; German Centre for Cardiovascular Research, Mainz 55131, Germany
| | - Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Dr, Charleston, South Carolina 29425, USA
| |
Collapse
|
4
|
Henning MK, Aaløkken TM, Johansen S. Contrast medium protocols in routine chest CT: a survey study. Acta Radiol 2022; 63:351-359. [PMID: 33648351 DOI: 10.1177/0284185121997111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Administration of contrast medium (CM) is an important image quality factor in computed tomography (CT) of the chest. There is no clear evidence or guidelines on CM strategies for chest CT, thus a consensus approach is needed. PURPOSE To survey the potential impact on differences in chest CT protocols, with emphasis on strategies for the administration of CM. MATERIAL AND METHODS A total of 170 respondents were included in this survey, which used two different approaches: (i) an online survey was sent to the members of the European Society of Thoracic Imaging (ESTI); and (ii) an email requesting a copy of their CT protocol was sent to all hospitals in Norway, and university hospitals in Sweden and Denmark. The survey focused on factors affecting CM protocols and enhancement in chest CT. RESULTS The overall response rate was 24% (n = 170): 76% of the respondents used a CM concentration of ≥350 mgI/mL; 52% of the respondents used a fixed CM volume strategy. Fixed strategies for injection rate and delay were also the most common approach, practiced by 73% and 57% of the respondents, respectively. The fixed delay was in the range of 20-90 s. Of the respondents, 56% used flexible tube potential strategies (kV). CONCLUSION The chest CT protocols and CM administration strategies employed by the respondents vary widely, affecting the image quality. The results of this study underline the need for further research and consensus guidelines related to chest CT.
Collapse
Affiliation(s)
- Mette Karen Henning
- Faculty of Health Sciences, Department of Life Sciences and Health, Oslo Metropolitan University, Oslo, Norway
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - Trond Mogens Aaløkken
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
- Faulty of Medicine, University of Oslo, Oslo, Norway
| | - Safora Johansen
- Faculty of Health Sciences, Department of Life Sciences and Health, Oslo Metropolitan University, Oslo, Norway
- Department of Cancer Treatment, Oslo University Hospital, Oslo, Norway
| |
Collapse
|
5
|
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.
Collapse
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.
| |
Collapse
|
6
|
Euler A, Taslimi T, Eberhard M, Kobe A, Reeve K, Zimmermann A, Krauss A, Gutjahr R, Schmidt B, Alkadhi H. Computed Tomography Angiography of the Aorta-Optimization of Automatic Tube Voltage Selection Settings to Reduce Radiation Dose or Contrast Medium in a Prospective Randomized Trial. Invest Radiol 2021; 56:283-291. [PMID: 33226202 DOI: 10.1097/rli.0000000000000740] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES The aim of this study was to compare the image quality of low-kV protocols with optimized automatic tube voltage selection (ATVS) settings to reduce either radiation dose or contrast medium (CM) with that of a reference protocol for computed tomography angiography (CTA) of the thoracoabdominal aorta. MATERIALS AND METHODS In this institutional review board-approved, single-center, prospective randomized controlled trial, 126 patients receiving CTA of the aorta were allocated to one of three computed tomography protocols: (A) reference protocol at 120 kVp and standard weight-adapted CM dose; (B) protocol at 90 kVp, reduced radiation and standard CM dose; and (C) protocol at 90 kVp, standard radiation and reduced CM dose. All three protocols were performed on a third-generation dual-source computed tomography scanner using the semimode of the ATVS system. The image-task-dependent optimization settings of the ATVS (slider level) were adjusted to level 11 (high-contrast task) for protocols A and B and level 3 (low-contrast task) for protocol C. Radiation dose parameters were assessed. The contrast-to-noise ratios (CNRs) of protocols B and C were tested for noninferiority compared with A. Subjective image quality was assessed using a 5-point Likert scale. RESULTS Size-specific dose estimate was 34.3% lower for protocol B compared with A (P < 0.0001). Contrast medium was 20.2% lower for protocol C compared with A (P < 0.0001). Mean CNR in B and C was noninferior to protocol A (CNR of 30.2 ± 7, 33.4 ± 6.7, and 30.5 ± 8.9 for protocols A, B, and C, respectively). There was no significant difference in overall subjective image quality among protocols (4.09 ± 0.21, 4.03 ± 0.19, and 4.08 ± 0.17 for protocols A, B, and C, respectively; P = 0.4). CONCLUSIONS The slider settings of an ATVS system can be adjusted to optimize either radiation dose or CM at noninferior image quality in low-kV CTA of the aorta. This optimization could be used to extend future ATVS algorithms to take clinical risk factors like kidney function of individual patients into account.
Collapse
Affiliation(s)
- André Euler
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Tilo Taslimi
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Matthias Eberhard
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Adrian Kobe
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Kelly Reeve
- Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland
| | - Alexander Zimmermann
- Department of Vascular Surgery, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | | | | | | | - Hatem Alkadhi
- From the Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| |
Collapse
|
7
|
Bebbington NA, Jørgensen T, Dupont E, Micheelsen MA. Validation of CARE kV automated tube voltage selection for PET-CT: PET quantification and CT radiation dose reduction in phantoms. EJNMMI Phys 2021; 8:29. [PMID: 33743091 PMCID: PMC7981373 DOI: 10.1186/s40658-021-00373-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 02/25/2021] [Indexed: 11/20/2022] Open
Abstract
Background Applied tube voltage (kilovolts, kV) and tube current (milliampere seconds, mAs) affect CT radiation dose and image quality and should be optimised for the individual patient. CARE kV determines the kV and mAs providing the lowest dose to the patient, whilst maintaining user-defined reference image quality. Given that kV changes affect CT values which are used to obtain attenuation maps, the aim was to evaluate the effect of kV changes on PET quantification and CT radiation dose using phantoms. Method Four phantoms (‘Lungman’, ‘Lungman plus fat’, ‘Esser’ and ‘NEMA image quality’ (NEMA IQ)) containing F-18 sources underwent 1 PET and 5 CT scans, with CARE kV on (automatic kV selection and mAs modulation) and in semi mode with specified tube voltages of 140, 120, 100 and 80 kV (mAs modulation only). A CARE kV image quality reference of 120 kV/50 mAs was used. Impact on PET quantification was determined by comparing measured activity concentrations for PET reconstructions from different CT scans with the reconstruction using the 120 kV reference, and dose (DLP, CTDIvol) differences calculated by comparing doses from all kV settings with the 120 kV reference. Results CARE kV-determined optimal tube voltage and CARE kV ‘on’ dose (DLP) savings compared with the 120 kV reference were: Lungman, 100 kV, 2.0%; Lungman plus fat, 120 kV, 0%; Esser, 100 kV, 9.3%; NEMA IQ, 100 kV, 3.4%. Using tube voltages in CARE kV ‘semi’ mode which were not advised by CARE kV ‘on’ resulted in dose increases ≤ 65% compared with the 120 kV reference (greatest difference Lungman plus fat, 80 kV). Clinically insignificant differences in PET activity quantification of up to 0.7% (Lungman, 100 kV, mean measured activity concentration) were observed when using the optimal tube voltage advised by CARE kV. Differences in PET quantification of up to 4.0% (Lungman, 140 kV, maximum measured activity concentration) were found over the full selection of tube voltages in semi mode, with the greatest differences seen at the most suboptimal kV for each phantom. However, most differences were within 1%. Conclusions CARE kV on can provide CT radiation dose savings without concern over changes in PET quantification.
Collapse
Affiliation(s)
- Natalie A Bebbington
- Siemens Healthcare A/S, Bredskifte Alle 15, 8210, Aarhus V, Denmark. .,Department of Clinical Medicine, Aalborg University, Søndre Skovvej 15, 9000, Aalborg, Denmark.
| | - Troels Jørgensen
- Department of Nuclear Medicine, Zealand University Hospital, Køge, Denmark
| | - Erik Dupont
- Department of Biomedical Engineering, Region Zealand, Roskilde, Denmark
| | - Mille A Micheelsen
- Department of Nuclear Medicine, Zealand University Hospital, Køge, Denmark
| |
Collapse
|
8
|
Solbak MS, Henning MK, England A, Martinsen AC, Aaløkken TM, Johansen S. Impact of iodine concentration and scan parameters on image quality, contrast enhancement and radiation dose in thoracic CT. Eur Radiol Exp 2020; 4:57. [PMID: 32915405 PMCID: PMC7486352 DOI: 10.1186/s41747-020-00184-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 08/12/2020] [Indexed: 12/11/2022] Open
Abstract
Background We investigated the impact of varying contrast medium (CM) densities and x-ray tube potentials on contrast enhancement (CE), image quality and radiation dose in thoracic computed tomography (CT) using two different scanning techniques. Methods Seven plastic tubes containing seven different CM densities ranging from of 0 to 600 HU were positioned inside a commercial chest phantom with padding, representing three different patient sizes. Helical scans of the phantom in single-source mode were obtained with varying tube potentials from 70 to 140 kVp. A constant volume CT dose index (CTDIvol) depending on phantom size and automatic dose modulation was tested. CE (HU) and image quality (contrast-to-noise ratio, CNR) were measured for all combinations of CM density and tube potential. A reference threshold of CE and kVp was defined as ≥ 200 HU and 120 kVp. Results For the medium-sized phantom, with a specific CE of 100–600 HU, the diagnostic CE (200 HU) at 70 kVp was ~ 90% higher than at 120 kVp, for both scan techniques (p < 0.001). Changes in CM density/specific HU together with lower kVp resulted in significantly higher CE and CNR (p < 0.001). When changing only the kVp, no statistically significant differences were observed in CE or CNR (p ≥ 0.094), using both dose modulation and constant CTDIvol. Conclusions For thoracic CT, diagnostic CE (≥ 200 HU) and maintained CNR were achieved by using lower CM density in combination with lower tube potential (< 120 kVp), independently of phantom size.
Collapse
Affiliation(s)
- Marian S Solbak
- Faculty of Health Sciences, Oslo Metropolitan University, Pilestredet 48, 0130, Oslo, Norway
| | - Mette K Henning
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - Andrew England
- School of Allied Health Professions, Keele University, Staffordshire, England
| | - Anne C Martinsen
- Faculty of Health Sciences, Oslo Metropolitan University, Pilestredet 48, 0130, Oslo, Norway.,Department of Diagnostic Physics, Oslo University Hospital, Oslo, Norway
| | - Trond M Aaløkken
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.,Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Safora Johansen
- Faculty of Health Sciences, Oslo Metropolitan University, Pilestredet 48, 0130, Oslo, Norway. .,Department of Cancer Treatment, Oslo University Hospital, Oslo, Norway.
| |
Collapse
|
9
|
Tailoring Contrast Media Protocols to Varying Tube Voltages in Vascular and Parenchymal CT Imaging: The 10-to-10 Rule. Invest Radiol 2020; 55:673-676. [PMID: 32898358 DOI: 10.1097/rli.0000000000000682] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The latest technical developments in CT have created the possibility for individualized scan protocols at variable kV settings. Lowering tube voltages closer to the K-edge of iodine increases attenuation. However, the latter is also influenced by patient characteristics such as total body weight. To maintain a robust contrast enhancement throughout the patient population in both vascular and parenchymal CT scans, one must adapt the contrast media administration protocols to both the selected kV setting and patient body habitus. This article proposes a simple rule of thumb for how to adapt the contrast media protocol to any kV setting: the 10-to-10 rule.
Collapse
|
10
|
Personalization of CM Injection Protocols in Coronary Computed Tomographic Angiography (People CT Trial). CONTRAST MEDIA & MOLECULAR IMAGING 2020; 2020:5407936. [PMID: 32410922 PMCID: PMC7201621 DOI: 10.1155/2020/5407936] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 11/22/2019] [Indexed: 02/04/2023]
Abstract
Aim To evaluate the performance of three contrast media (CM) injection protocols for cardiac computed tomography angiography (CCTA) based on body weight (BW), lean BW (LBW), and cardiac output (CO). Materials and methods. A total of 327 consecutive patients referred for CCTA were randomized into one of the three CM injection protocols, where CM injection was based on either BW (112 patients), LBW (108 patients), or CO (107 patients). LBW and CO were calculated via formulas. All scans were ECG-gated and performed on a third-generation dual-source CT with 70-120 kV (automated tube voltage selection) and 100 kVqual.ref/330 mAsqual.ref. CM injection protocols were also adapted to scan time and tube voltage. The primary outcome was the proportion of patients with optimal intravascular attenuation (325-500 HU). Secondary outcomes were mean and standard deviation of intravascular attenuation values (HU), contrast-to-noise ratio (CNR), and subjective image quality with a 4-point Likert scale (1 = poor/2 = sufficient/3 = good/4 = excellent). The t-test for independent samples was used for pairwise comparisons between groups, and a chi-square test (χ2) was used to compare categorical variables between groups. All p values were 2-sided, and a p < 0.05 was considered statistically significant. Results Mean overall HU and CNR were 423 ± 60HU/14 ± 3 (BW), 404 ± 62HU/14 ± 3 (LBW), and 413 ± 63HU/14 ± 3 (CO) with a significant difference between groups BW and LBW (p=0.024). The proportion of patients with optimal intravascular attenuation (325-500 HU) was 83.9%, 84.3%, and 86.9% for groups BW, LBW, and CO, respectively, and between-group differences were small and nonsignificant. Mean CNR was diagnostic (≥10) in all groups. The proportion of scans with good-excellent image quality was 94.6%, 86.1%, and 90.7% in the BW, LBW, and CO groups, respectively. The difference between proportions was significant between the BW and LBW groups. Conclusion Personalization of CM injection protocols based on BW, LBW, and CO, and scan time and tube voltage in CCTA resulted in low variation between patients in terms of intravascular attenuation and a high proportion of scans with an optimal intravascular attenuation. The results suggest that personalized CM injection protocols based on LBW or CO have no additional benefit when compared with CM injection protocols based on BW.
Collapse
|
11
|
Improved Visualization and Identification of the Right Adrenal Vein in 70-kVp Contrast-Enhanced Computed Tomography. J Comput Assist Tomogr 2020; 44:153-159. [PMID: 31939897 DOI: 10.1097/rct.0000000000000960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE The aim of this study was to assess the utility of 70-kilovoltage-peak (kVp) contrast-enhanced computed tomography (CECT) for visualization and identification of the right adrenal vein (RAV) in comparison with that of conventional 120-kVp CECT. METHODS This retrospective study included patients who underwent adrenal venous sampling with concurrent biphasic 120-kVp (120-kVp group, n = 43) or 70-kVp (70-kVp group, n = 47) CECT. Signal-to-noise ratios, contrast-to-noise ratios, longitudinal lengths, conspicuity scores, RAV detection rates, and size-specific dose estimates were compared between the 2 groups. RESULTS In comparison with the 120-kVp group, the 70-kVp group had significantly higher signal-to-noise and contrast-to-noise ratios (P < 0.001-P = 0.033), greater longitudinal lengths (P < 0.001-P = 0.002), superior conspicuity scores for the RAV (P < 0.001), higher RAV detection rates (P = 0.015-P = 0.033), and lower size-specific dose estimates (P < 0.001). CONCLUSIONS Seventy-kilovoltage-peak CECT has advantages over conventional 120-kVp CECT and is potentially useful for noninvasive assessment of the precise anatomy of the RAV.
Collapse
|
12
|
Yuan W, Qu TT, Wang HJ, Wang MY, Qu Y, Niu G, Yang J. Coronary CT Angiography Using Low Iodine Delivery Rate and Tube Voltage Determined by Body Mass Index: Superiority in Clinical Practice. Curr Med Sci 2019; 39:825-830. [PMID: 31612403 DOI: 10.1007/s11596-019-2112-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 05/23/2019] [Indexed: 12/24/2022]
Abstract
To explore the feasibility and superiority of iodine delivery rate (IDR) and tube voltage determined by patients' body mass index (BMI) in coronary CT angiography (CCTA), a total of 1567 patients undertaking CCTA during Feb. and Dec. 2016 were enrolled and divided into two groups. In the control group, the IDR and tube voltage were fixed, while in the experimental group, the IDR and tube voltage were determined by patients' BMI. The volume of iodinated contrast media (ICM), extravasation rate, extravasation volume, extravasation recovery interval, incidence rate of adverse reactions, effective dose (ED) and image quality of the two groups were compared. The experiments demonstrated that the ICM volume, extravasation rate, extravasation volume, extravasation recovery interval, incidence of adverse reactions and ED were lower or shorter in the experimental group than in the control group, and the differences were statistically significant (all P<0.05). However, there were no significant differences in the mean CT value, image noise, signal to noise ratio and contrast to noise ratio between the two groups (all P<0.05), which were consistent with the diagnosticians' subjective evaluation outcomes. Our findings suggested that in CCTA, it is feasible to determine the IDR and tube voltage based on patients' BMI; low tube voltage and IDR are superior to the fixed tube voltage and IDR and are worthy of clinical promotion.
Collapse
Affiliation(s)
- Wang Yuan
- Department of Diagnostic Radiology, the First Hospital of Medical Science Centre, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Ting-Ting Qu
- Department of Diagnostic Radiology, the First Hospital of Medical Science Centre, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Hui-Juan Wang
- Department of Dermatology, the Ninth Hospital of Xi'an, Xi'an, 710054, China
| | - Mei-Yu Wang
- Department of Diagnostic Radiology, the First Hospital of Medical Science Centre, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Yuan Qu
- Department of Diagnostic Radiology, the First Hospital of Medical Science Centre, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Gang Niu
- Department of Diagnostic Radiology, the First Hospital of Medical Science Centre, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Jian Yang
- Department of Diagnostic Radiology, the First Hospital of Medical Science Centre, Xi'an Jiaotong University, Xi'an, 710061, China.
| |
Collapse
|
13
|
Rengo M, Dharampal A, Lubbers M, Kock M, Wildberger JE, Das M, Niezen A, van Tilborg F, Kofflard M, Laghi A, Krestin G, Nieman K. Impact of iodine concentration and iodine delivery rate on contrast enhancement in coronary CT angiography: a randomized multicenter trial (CT-CON). Eur Radiol 2019; 29:6109-6118. [PMID: 31016447 DOI: 10.1007/s00330-019-06196-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/27/2019] [Accepted: 03/22/2019] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To compare the effect of contrast medium iodine concentration on contrast enhancement, heart rate, and injection pressure when injected at a constant iodine delivery rate in coronary CT angiography (CTA). METHODS One thousand twenty-four patients scheduled for coronary CTA were prospectively randomized to receive one of four contrast media: iopromide 300 mg I/ml, iohexol 350 mg I/ml, iopromide 370 mg I/ml, or iomeprol 400 mg I/ml. Contrast media were delivered at an equivalent iodine delivery rate of 2.0 g I/s. Intracoronary attenuation was measured and compared (per vessel and per segment). Heart rate before and after contrast media injection was documented. Injection pressure was recorded (n = 403) during contrast medium injection and compared between groups. RESULTS Intracoronary attenuation values were similar for the different contrast groups. The mean attenuation over all segments ranged between 384 HU for 350 mg I/ml and 395 HU for 400 mg I/ml (p = 0.079). Dose-length product (p = 0.8424), signal-to-noise ratio (all p > 0.05), time to peak (p = 0.324), and changes in heart rate (p = 0.974) were comparable between groups. The peak pressures differed: 197.4 psi for 300 mg I/ml (viscosity 4.6 mPa s), 229.8 psi for 350 mg I/ml (10.4 mPa s), 216.1 psi for 370 mg I/ml (9.5 mPa s), and 243.7 psi for 400 mg I/ml (12.6 mPa s) (p < 0.0001). CONCLUSION Intravascular attenuation and changes in heart rate are independent of iodine concentration when contrast media are injected at the same iodine delivery rate. Differences in injection pressures are associated with the viscosity of the contrast media. KEY POINTS • The contrast enhancement in coronary CT angiography is independent of the iodine concentration when contrast media are injected at body temperature (37 °C) with the same iodine delivery rate. • Iodine concentration does not influence the change in heart rate when contrast media are injected at identical iodine delivery rates. • For a fixed iodine delivery rate and contrast temperature, the viscosity of the contrast medium affects the injection pressure.
Collapse
Affiliation(s)
- Marco Rengo
- Faculty of Pharmacy and Medicine, University of Rome Sapienza, Latina, Italy
| | - Anoeshka Dharampal
- Departments of Radiology and Cardiology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Marisa Lubbers
- Departments of Radiology and Cardiology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Marc Kock
- Department of Radiology, Albert Schweitzer Ziekenhuis, Dordrecht, the Netherlands
| | - Joachim E Wildberger
- Department of Radiology and Nuclear Medicine, Maastricht UMC+, Maastricht, the Netherlands
| | - Marco Das
- Department of Radiology and Nuclear Medicine, Maastricht UMC+, Maastricht, the Netherlands
| | - André Niezen
- Department of Radiology and Nuclear medicine, Maasstad Ziekenhuis, Rotterdam, the Netherlands
| | - Fiek van Tilborg
- Department of Radiology, Elisabeth-TweeSteden Ziekenhuis, Tilburg, The Netherlands
| | - Marcel Kofflard
- Department of Cardiology, Albert Schweitzer Ziekenhuis, Dordrecht, the Netherlands
| | - Andrea Laghi
- Department of Surgical and Medical Sciences and Translational Medicine, University of Rome Sapienza, Rome, Italy
| | - Gabriel Krestin
- Department of Radiology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Koen Nieman
- Departments of Radiology and Cardiology, Erasmus University Medical Center, Rotterdam, The Netherlands. .,Stanford University School of Medicine and Cardiovascular Institute, 300 Pasteur Dr, Room H2157, Stanford, CA, 94305, USA.
| |
Collapse
|
14
|
Optimizing Pulmonary Embolism Computed Tomography in the Age of Individualized Medicine: A Prospective Clinical Study. Invest Radiol 2019; 53:306-312. [PMID: 29438139 DOI: 10.1097/rli.0000000000000443] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE The aim of the study was to simultaneously optimize contrast media (CM) injection and scan parameters for the individual patient during computed tomography pulmonary angiography (CTPA). METHODS In this study (NCT02611115), 235 consecutive patients suspected of having pulmonary embolism were prospectively enrolled. Automated kV selection software on a third-generation multidetector computed tomography adapted tube voltage to the individual patient, based on scout scans. The contrast injection protocol was adapted to both patient body weight and kV-setting selection via a predefined formula, based on previous research. Injection data were collected from a contrast media and radiation dose monitoring software. Attenuation was measured in Hounsfield units (HU) in the pulmonary trunk (PT); attenuation values 200 HU or greater were considered diagnostic. Subjective image quality was assessed by using a 4-point Likert scale at the level of the PT, lobar, segmental, and subsegmental arteries. Results between groups were reported as mean ± SD. RESULTS Two hundred twenty-two patients (94%) were scanned at a kV setting below 100 kV: n = 108 for 70 kV, n = 82 for 80 kV, and n = 32 for 90 kV. Mean CM bolus volume (in milliliters) and total iodine load (in grams of iodine) for 70 to 90 kV were as follows: 24 ± 3 mL and 7 ± 1 g I, 29 ± 4 mL and 9 ± 2 g I, and 38 ± 4 mL and 11 ± 1 g I, respectively. Mean flow rates (in milliliters per second) and iodine delivery rates (in grams of iodine per second) were 3.0 ± 0.4 mL/s and 0.9 ± 0.1 g I/s (70 kV), 3.6 ± 0.4 mL/s and 1.0 ± 0.1 g I/s (80 kV), and 4.7 ± 0.5 mL/s and 1.3 ± 0.1 g I/s (90 kV). Mean radiation doses were 1.3 ± 0.3 mSv at 70 kV, 1.7 ± 0.4 mSv at 80 kV, and 2.2 ± 0.6 mSv at 90 kV. Mean vascular attenuation in the PT for each kV group was as follows: 397 ± 101 HU for 70 kV, 398 ± 96 HU for 80 kV, and 378 ± 100 HU for 90 kV, P = 0.59. Forty-six patients (21%) showed pulmonary embolism on the CTPA. One scan (90 kV) showed nondiagnostic segmental pulmonary arteries, and 5% of subsegmental arteries were of nondiagnostic image quality. All other segments were considered diagnostic-excellent subjective image quality. CONCLUSIONS Simultaneously optimizing both CM injections and kV settings to the individual patient in CTPA results in diagnostic attenuation with on average 24 to 38 mL of CM volume and a low radiation dose for most patients. This individualized protocol may help overcome attenuation-variation problems between patients and kV settings in CTPA.
Collapse
|
15
|
Kubo T. Vendor free basics of radiation dose reduction techniques for CT. Eur J Radiol 2018; 110:14-21. [PMID: 30599851 DOI: 10.1016/j.ejrad.2018.11.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 10/19/2018] [Accepted: 11/04/2018] [Indexed: 11/16/2022]
Abstract
Although radiation dose in computed tomography (CT) decreased and CT became safer examinations than before, CT is the most significant source of the medical radiation exposure. Knowledge about available radiation dose reduction methods in CT is essential. Substantial improvement occurred regarding tube current selection (automatic exposure control) and image production method (iterative reconstruction). Optimizing the tube potential selection is expected to contribute to further CT radiation dose reduction. This review article summarizes the principles of radiation dose reduction in CT, principal methods of radiation dose reduction, auxiliary measures of radiation dose saving and recent issues of low dose CT.
Collapse
Affiliation(s)
- Takeshi Kubo
- Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
| |
Collapse
|
16
|
Personalization of injection protocols to the individual patient's blood volume and automated tube voltage selection (ATVS) in coronary CTA. PLoS One 2018; 13:e0203682. [PMID: 30256835 PMCID: PMC6157854 DOI: 10.1371/journal.pone.0203682] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 08/25/2018] [Indexed: 12/27/2022] Open
Abstract
Purpose The aim was to assess personalised contrast media (CM) protocols—based on patient’s blood volume (BV) and automated tube voltage selection (ATVS)—in coronary computed tomography angiography (CCTA). Methods A total of 114 consecutive patients received an ECG-triggered or ECG-gated helical scan on a 3rd-generation dual-source CT with 70-120kV (ATVS) and 330mAsqual.ref. CM was adapted to BV, scan time (s) and kV. Image quality (IQ) was assessed in a 17-segment coronary model using attenuation values (HU), contrast-to-noise (CNR), signal-to-noise ratio (SNR) (objective IQ) and a Likert scale (subjective IQ: 1 = poor/2 = sufficient/3 = good/4 = excellent). ig Results Patient distribution was: n = 60 for 70kV, n = 37 80kV and n = 17 90kV. Mean BV was 5.4±0.6L for men and 4.1±0.6L for women. Mean CM volume (300 mg I/mL) and flow rate were: 30.9±6.4mL and 3.3±0.5mL/s (70kV); 40.8±7.1mL and 4.5±0.6mL/s (80kV); 53.6±8.6mL and 5.7±0.6mL/s (90kV). Overall mean HU was >300HU in 98.2% (112/114) of patients. Overall mean attenuation was below 300HU in two scans (70kV) due to late scan timing. Of 1.661 segments, 95.4% was assessable. Mean CNR was 14±4(70kV), 13±3(80kV) and 14±4(90kV); mean SNR was 10±2(both 70kV+80kV) and 9±2(90kV). Objective IQ was comparable between kV settings, protocols and sex. Subjective IQ was diagnostic in all scans and excellent-sufficient in 95.4% of segments. Conclusions Personalisation of CCTA CM injection protocols to BV and ATVS is a promising technique to tailor CM administration to the individual patient, while maintaining diagnostic IQ.
Collapse
|
17
|
Implementation of Size-Dependent Local Diagnostic Reference Levels for CT Angiography. AJR Am J Roentgenol 2018; 210:W226-W233. [DOI: 10.2214/ajr.17.18566] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
18
|
Van Cauteren T, Van Gompel G, Tanaka K, Verdries DE, Belsack D, Nieboer KH, Willekens I, Evans P, Macholl S, Verfaillie G, Droogmans S, de Mey J, Buls N. The Impact of Combining a Low-Tube Voltage Acquisition with Iterative Reconstruction on Total Iodine Dose in Coronary CT Angiography. BIOMED RESEARCH INTERNATIONAL 2017; 2017:2476171. [PMID: 28620616 PMCID: PMC5460391 DOI: 10.1155/2017/2476171] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/16/2017] [Accepted: 03/28/2017] [Indexed: 11/18/2022]
Abstract
OBJECTIVES To assess the impact of combining low-tube voltage acquisition with iterative reconstruction (IR) techniques on the iodine dose in coronary CTA. METHODS Three minipigs underwent CCTA to compare a standard of care protocol with two alternative study protocols combining low-tube voltage and low iodine dose with IR. Image quality was evaluated objectively by the CT value, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in the main coronary arteries and aorta and subjectively by expert reading. Statistics were performed by Mann-Whitney U test and Chi-square analysis. RESULTS Despite reduced iodine dose, both study protocols maintained CT values, SNR, and CNR compared to the standard of care protocol. Expert readings confirmed these findings; all scans were perceived to be of at least diagnostically acceptable quality on all evaluated parameters allowing image interpretation. No statistical differences were observed (all p values > 0.11), except for streak artifacts (p = 0.02) which were considered to be more severe, although acceptable, with the 80 kVp protocol. CONCLUSIONS Reduced tube voltage in combination with IR allows a total iodine dose reduction between 37 and 50%, by using contrast media with low iodine concentrations of 200 and 160 mg I/mL, while maintaining image quality.
Collapse
Affiliation(s)
- Toon Van Cauteren
- Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090 Brussels, Belgium
| | - Gert Van Gompel
- Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090 Brussels, Belgium
| | - Kaoru Tanaka
- Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090 Brussels, Belgium
| | - Douwe E. Verdries
- Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090 Brussels, Belgium
| | - Dries Belsack
- Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090 Brussels, Belgium
| | - Koenraad H. Nieboer
- Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090 Brussels, Belgium
| | - Inneke Willekens
- Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090 Brussels, Belgium
| | - Paul Evans
- Imaging R&D, GE Healthcare Life Sciences, The Grove Centre, Amersham, Buckinghamshire, UK
| | - Sven Macholl
- Imaging R&D, GE Healthcare Life Sciences, The Grove Centre, Amersham, Buckinghamshire, UK
| | - Guy Verfaillie
- Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090 Brussels, Belgium
| | - Steven Droogmans
- Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090 Brussels, Belgium
| | - Johan de Mey
- Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090 Brussels, Belgium
| | - Nico Buls
- Radiology, Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090 Brussels, Belgium
| |
Collapse
|
19
|
Optimizing Contrast Media Injection Protocols in Computed Tomography Angiography at Different Tube Voltages. J Comput Assist Tomogr 2017; 41:804-810. [DOI: 10.1097/rct.0000000000000613] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|