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Wong YM, Ong CC, Liang CR, Tan CA, Teo LLS. Image quality, contrast enhancement and radiation dose of electrocardiograph- versus non-electrocardiograph-triggered computed tomography angiography of the aorta. Singapore Med J 2024; 65:84-90. [PMID: 34688230 PMCID: PMC10942131 DOI: 10.11622/smedj.2021166] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 09/28/2021] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Computed tomography angiography of the aorta (CTAA) is the modality of choice for investigating aortic disease. Our aim was to evaluate the image quality, contrast enhancement and radiation dose of electrocardiograph (ECG)-triggered and non-ECG-triggered CTAA on a 256-slice single-source CT scanner. This allows the requesting clinician and the radiologist to balance radiation risk and image quality. METHODS We retrospectively assessed the data of 126 patients who had undergone CTAA on a single-source CT scanner using ECG-triggered (group 1, n = 77) or non-ECG-triggered (group 2, n = 49) protocols. Radiation doses were compared. Qualitative (4-point scale) and quantitative image quality assessments were performed. RESULTS The mean volume CT dose index, dose length product and effective dose in group 1 were 12.4 ± 1.9 mGy, 765.8 ± 112.4 mGy cm and 13.0 ± 1.9 mSv, respectively. These were significantly higher compared to group 2 values (9.1 ± 2.6 mGy, 624.1 ± 174.8 mGy cm and 10.6 ± 3.0 mSv, respectively) ( P < 0.001). Qualitative assessment showed the image quality at the aortic root-proximal ascending aorta was significantly higher in group 1 (median 3) than in group 2 (median 2, P < 0.001). Quantitative assessment showed significantly better mean arterial attenuation, signal-to-noise ratio and contrast-to-noise ratio in ECG-triggered CTAA compared to non-ECG-triggered CTAA. CONCLUSION ECG-triggered CTAA in a single-source scanner has superior image quality and vessel attenuation of aortic root/ascending aorta, but a higher radiation dose of approximately 23%. Its use should be considered specifically when assessing aortic root/ascending aorta pathology.
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Affiliation(s)
- Ying Mei Wong
- Department of Diagnostic Imaging, National University Hospital, Singapore
| | - Ching Ching Ong
- Department of Diagnostic Imaging, National University Hospital, Singapore
| | - Chong Ri Liang
- Department of Diagnostic Imaging, National University Hospital, Singapore
| | - Choon Ann Tan
- Department of Diagnostic Imaging, National University Hospital, Singapore
| | - Lynette Li San Teo
- Department of Diagnostic Imaging, National University Hospital, Singapore
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2
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Double rule-out technique for evaluation of acute chest pain using 128-row multidetector CT. Clin Radiol 2022; 77:e231-e240. [PMID: 35000763 DOI: 10.1016/j.crad.2021.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 12/16/2021] [Indexed: 11/23/2022]
Abstract
AIM To evaluate the feasibility and image quality of the double rule-out (DRO) technique using 128-row multidetector computed tomography (CT) for simultaneous evaluation of the aorta and coronary arteries in patients with acute non-specific chest pain. MATERIALS AND METHODS Sixty-eight patients underwent electrocardiography (ECG)-gated coronary CT followed by non-ECG-gated abdominal CT. The contrast-to-noise ratio and signal-to-noise ratio between the vessels and adjacent perivascular fat tissue were calculated for both the aorta and coronary arteries. Dose-length products were recorded. Two blinded readers graded the image quality of the aorta and coronary arteries on a two-point and a four-point scale, respectively. In addition, the severity of coronary stenosis was independently analysed for each coronary vessel. RESULTS The average attenuation was more than 350 HU for the aorta and >330 HU for the coronary arteries. The average (±standard deviation) volume of contrast media was 69.5 ± 12.5 ml. Interobserver agreement on the image quality of aortic and coronary data sets was perfect and substantial, respectively. There was almost perfect interobserver agreement for the all observations of the severity of coronary stenosis. CONCLUSION The DRO technique with a standard volume (approximately 70 ml) of contrast media is useful for acute chest pain evaluation in patients suspected of having acute aortic syndrome or acute coronary syndrome. It is also accurate and safe while maintaining the average CT attenuation of the aorta and coronary arteries >330 HU.
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3
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Roberts W, Charles SM, Ang C, Holda MK, Walocha J, Lachman N, Tubbs RS, Loukas M. Myocardial bridges: A meta-analysis. Clin Anat 2021; 34:685-709. [PMID: 33078444 DOI: 10.1002/ca.23697] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/11/2020] [Accepted: 10/12/2020] [Indexed: 12/11/2022]
Abstract
Myocardial bridges are anatomical entities characterized by myocardium covering segments of coronary arteries. In some patients, the presence of a myocardial bridge is benign and is only incidentally found on autopsy. In other patients, however, myocardial bridges can lead to compression of the coronary artery during systolic contraction and delayed diastolic relaxation, resulting in myocardial ischemia. This ischemia in turn can lead to myocardial infarction, ventricular arrhythmias and sudden cardiac death. Myocardial bridges have also been linked to an increased incidence of atherosclerosis, which has been attributed to increased shear stress and the presence of vasoactive factors. Other studies however, demonstrated the protective roles of myocardial bridges. In this study, using systematic review and a meta-analytical approach we investigate the prevalence and morphology of myocardial bridges in both clinical imaging and cadaveric dissections. We also discuss the pathophysiology, clinical significance, and management of these anatomical entities.
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Affiliation(s)
- Wallisa Roberts
- Department of Medicine, Princess Royal Hospital, Apley Castle, Telford Shropshire, UK
| | - Stacey M Charles
- Department of Anatomical Sciences, St. George's University, School of Medicine, Grenada, West Indies
| | - Cassandra Ang
- Department of Medicine, Princess Royal Hospital, Apley Castle, Telford Shropshire, UK
| | - Mateusz K Holda
- HEART-Heart Embryology and Anatomy Research Team, Department of Anatomy, Jagiellonian University Medical College, Cracow, Poland.,Division of Cardiovascular Sciences, The University of Manchester, England, UK
| | - Jerzy Walocha
- Department of Anatomy, Jagiellonian University, Medical College, Krakow, Poland
| | - Nirusha Lachman
- Department of Clinical Anatomy and Department of Plastic Surgery, Mayo Clinic College of Medicine and Science, Mayo Clinic, Rochester, Minnesota, USA
| | - R Shane Tubbs
- Department of Anatomical Sciences, St. George's University, School of Medicine, Grenada, West Indies.,Department of Neurosurgery, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, Louisiana, USA.,Department of Structural & Cellular Biology, Tulane University School of Medicine, New Orleans, Louisiana, USA.,Department of Neurosurgery and Ochsner Neuroscience Institute, Ochsner Health System, New Orleans, Louisiana, USA
| | - Marios Loukas
- Department of Anatomical Sciences, St. George's University, School of Medicine, Grenada, West Indies.,Department of Anatomy, University of Warmia and Mazury, Olsztyn, Poland
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Ippolito D, Riva L, Talei Franzesi C, De Vito A, Cangiotti C, Crespi A, Corso R, Sironi S. Computed Tomography Angiography Combined With Knowledge-Based Iterative Algorithm for Transcatheter Aortic Valve Implantation Planning: Image Quality and Radiation Dose Exposure With Low-kV and Low-Contrast-Medium Protocol. J Comput Assist Tomogr 2020; 44:13-19. [PMID: 31939876 DOI: 10.1097/rct.0000000000000965] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To evaluate image quality and radiation dose exposure of low-kV setting and low-volume contrast medium (CM) computed tomography angiography (CTA) protocol for transcatheter aortic valve implantation (TAVI) planning in comparison with standard CTA protocol. METHODS Sixty-patients were examined with 256-row MDCT for TAVI planning: 32 patients (study group) were evaluated using 80-kV electrocardiogram-gated protocol with 60 mL of CM and IMR reconstruction; 28 patients underwent a standard electrocardiogram-gated CTA study (100 kV; 80 mL of CM; iDose4 reconstruction). Subjective and objective image quality was evaluated in each patient at different aortic levels. Finally, we collected radiation dose exposure data (CT dose index and dose-length product) of both groups. RESULTS In study protocol, significant higher mean attenuation values were achieved in all measurements compared with the standard protocol. There were no significant differences in the subjective image quality evaluation in both groups. Mean dose-length product of study group was 56% lower than in the control one (P < 0.0001). CONCLUSION Low-kV and low-CM volume CTA, combined with IMR, allows to correctly performing TAVI planning with high-quality images and significant radiation dose reduction compared with standard CTA protocol.
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Affiliation(s)
| | | | | | | | | | - Andrea Crespi
- Department of Medical Physics, "San Gerardo" Hospital, Monza
| | - Rocco Corso
- From the Department of Diagnostic Radiology, "San Gerardo" Hospital
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Hachulla AL, Noble S, Ronot M, Guglielmi G, de Perrot T, Montet X, Vallée JP. Low Iodine Contrast Injection for CT Acquisition Prior to Transcatheter Aortic Valve Replacement: Aorta Assessment and Screening for Coronary Artery Disease. Acad Radiol 2019; 26:e150-e160. [PMID: 30076081 DOI: 10.1016/j.acra.2018.06.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 06/17/2018] [Accepted: 06/18/2018] [Indexed: 10/28/2022]
Abstract
RATIONALE AND OBJECTIVES To assess both the complete aorta and coronary artery disease (CAD) using low iodine contrast computed-tomography angiography before transcatheter aortic valve replacement. MATERIALS AND METHODS 84 patients underwent computed-tomography angiography before transcatheter aortic valve replacement: 42 with standard iodine injection protocol (P1:120 mL); 42 with a low dose iodine injection protocol (P2:60 mL). Mean attenuation and subjective image quality were rated at different levels of the aorta, iliac and coronary arteries. Sensitivity, specificity, negative and positive predictive values for depiction of CAD were calculated according to the coronary angiography. RESULTS Mean attenuation was significantly higher in P1 for the ascending aorta (p < 0.001). No significant difference was observed regarding image quality of the aortic valve (p = 0.876), the ascending aorta (p = 0.306), or the abdominal aorta (p = 1.0). Diagnostic image quality of coronary arteries was excellent for P1 and P2 (94.6% vs 96.5%, p = 0.08). Sensitivity, specificity, negative and positive predictive values, and accuracy for depiction of CAD were excellent for P1 and P2 (100% vs 100%; 79% vs 86%, 70% vs 87%, 100% vs 100% and 86% vs 93%) without significant differences (p = 0.93; p = 0.58; p = 0.90; p = 1.0; p = 0.74), respectively. CONCLUSION Despite a difference in aortic mean attenuation, a reduced iodine injection protocol showed similar image quality and detection of CAD in comparison with a standard injection protocol.
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Talei Franzesi CR, Ippolito D, Riva L, Fior D, Cangiotti C, Sironi S. Diagnostic value of iterative reconstruction algorithm in low kV CT angiography (CTA) with low contrast medium volume for transcatheter aortic valve implantation (TAVI) planning: image quality and radiation dose exposure. Br J Radiol 2018; 91:20170802. [PMID: 30074831 PMCID: PMC6319841 DOI: 10.1259/bjr.20170802] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE: To evaluate image quality and radiation dose exposure of low-kV (100 kV) and low contrast medium (CM) volume CT angiography (CTA) in patients candidate to Transcatheter Aortic Valve Implantation (TAVI), in comparison with standard CTA protocol. METHODS: 79 patients candidate for TAVI were prospectively enrolled in this study and examined with 256-MDCT. 42 patients were evaluated using study-group protocol (100 kV; whole-body retrospective ECG-gating; with 50 ml of CM; iterative reconstruction algorithm) while 37 patients underwent a standard CTA study (120 kV; ECG-gating for chest; 100 ml of CM; FBP reconstruction). Overall image quality was evaluated using a 4-point scale. Vascular enhancement (HU) was then assessed in each patient by manually drawing multiple ROIs in lumen of 7 segments of the whole aorta. The radiation dose exposure of both groups was calculated and all data were compared and statistically analyzed. RESULTS: On low-kV protocol, higher mean attenuation values were achieved in all the measurements as compared to standard protocol. There were no significant differences in the image quality evaluation in both groups. Mean radiation dose value of study group was significantly lower than in control group (reduction of 20%). CONCLUSION: Low kV and low CM volume CTA protocols allow TAVI planning to be carried out with high quality images and a significant reduction in the radiation dose as compared to the standard CTA protocol. ADVANCES IN KNOWLEDGE: Low-kV CTA for pre-operative assessment of patients candidates for TAVI, permits to achieve a significant reduction of radiation dose exposure and contrast medium volume, reducing the risk of contrast induced nephropathy.
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Traumatic Coronary Artery Dissection with Secondary Acute Myocardial Infarction after Blunt Thoracic Trauma. J Belg Soc Radiol 2018; 102:4. [PMID: 30128419 PMCID: PMC6095083 DOI: 10.5334/jbr-btr.1379] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report the case of a 41-year-old male with traumatic coronary artery dissection after a high-speed motor vehicle collision. Computed tomography imaging revealed multiple intracranial subdural and subarachnoid bleedings, a skull base fracture and multiple bilateral rib fractures. There was no pericardial hemorrhage, haemothorax or pneumothorax. No intra-abdominal lesions were found. A 12-lead electrocardiogram on arrival showed an acute myocardial infarction. Emergency angiography showed complete dissection of the right coronary artery without reflow after placement of 6 coronary stents. The patient passed away the day after. In retrospective, the right coronary dissection was visible on the trauma CT-scan.
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8
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Liu S, Fu Q, Yu H, Zhang C, Yang Q, Hu Y, Xu W. Evaluate of the effect of low tube voltage on the radiation dosage using 640-slice coronary CT angiography. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2018; 26:463-471. [PMID: 29562576 DOI: 10.3233/xst-17332] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
BACKGROUND 640-slice coronary CT angiography is becoming an accurate and reliable method of diagnosing coronary heart disease. However, how to reduce the radiation dosage while ensuring the clinically acceptable image quality remains a quite challenging issue. OBJECTIVE To evaluate the effect of low tube voltage on radiation dosage under 640-slice coronary CT angiography (CCTA). METHODS Four hundred patients (236 males, 164 females) with coronary heart disease and underwent CCTA using DCVT were classified into A1 (tube voltage: 120 kV; exposure phase window: 30-80%), B1 (120 kV; 70-80%), A2 (100 kV; 30-80%) and B2 group (100 kV; 70-80%), respectively. Image qualities and effective dose (ED) were assessed and compared. RESULTS No significant differences were observed among the groups in terms of age, height, weight and body mass index (BMI) (P > 0.05). ED were significantly lower in 100 kV group (P < 0.05). CT values of coronary artery in 100 kV groups were 13.5% and 17.3% higher than 120 kV group. ED in B1 group were 64.5% and 67.0% lower than A1 group. ED in B2 group were 65.4% and 65.2% lower than A2 group. CONCLUSION When using a 640-slice CCTA prospective ECG-gating scanning mode, it is preferable to use a 100 kV tube voltage setting because compared to 120 kV tube voltage protocol, it seems to significantly decrease the mean effective radiation dose, without significantly lowering both the subjective and objective image quality.
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Affiliation(s)
- Shihe Liu
- Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Qing Fu
- Department of Ultrasound, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Hualong Yu
- Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Chuanyu Zhang
- Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Qing Yang
- Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yabin Hu
- Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Wenjian Xu
- Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
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9
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Wen D, Zhao H, Duan W, An R, Li J, Zheng M. Combined CT angiography of the aorta and craniocervical artery: a new imaging protocol for assessment of acute type A aortic dissection. J Thorac Dis 2017; 9:4733-4742. [PMID: 29268544 DOI: 10.21037/jtd.2017.09.28] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background To investigate the feasibility of combined computed tomography angiography (CTA) of the aorta and craniocervical artery in acute type A aortic dissection (ATAAD) and the value of incremental craniocervical information. Methods Combined CTA of head, neck and aorta was performed in patients with suspected aortic dissection and 243 ATAAD patients were analyzed. The image quality and radiation dose were assessed. Valuable craniocervical CTA findings were determined for further surgical analysis. Results The mean dose-length product (DLP) was 314.11±29.31 mGy.cm. The image quality of craniocervical arteries were 100% diagnostic. Intimal flap involving carotid arteries was detected in 47% of patients, and significant stenosis of true lumen was observed in 60% of common carotid arteries (CCAs). Hypodensity and hypoplasia/occlusion of carotid arteries were also detected and apprised surgeons. The tortuosity of carotid artery was found in 90.9% of patients. Bilateral antegrade selective cerebral perfusion (ASCP) was performed in 21.1% of aortic arch surgery based on 7 hemodynamic variation types of the circle of Willis (CW) determined by cranial CTA information. Conclusions A combined CTA of head, neck and aorta is feasible with low radiation dose and diagnostic image quality. Incremental information on craniocervical pathology and anatomy may be useful for surgery repair of ATAAD.
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Affiliation(s)
- Didi Wen
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Hongliang Zhao
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Weixun Duan
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Rui An
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Jian Li
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Minwen Zheng
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
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Hostiuc S, Negoi I, Rusu MC, Hostiuc M. Myocardial Bridging: A Meta-Analysis of Prevalence. J Forensic Sci 2017; 63:1176-1185. [PMID: 29044562 DOI: 10.1111/1556-4029.13665] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/02/2017] [Accepted: 09/05/2017] [Indexed: 01/27/2023]
Abstract
The main objective of this article was to analyze prevalence data about myocardial bridging (MB) in published studies. To this purpose, we performed a meta-analysis of studies published in English literature that contained data about the prevalence of MB and its anatomical characteristics. The overall prevalence was 19% (CI: 17-21%); autopsy studies revealed an overall prevalence of 42% (CI: 30-55%), CT studies 22% (CI: 18-25%), and coronary angiography 6% (CI: 5-8%). Most bridges were located on the left anterior descending artery (82% overall, 63% on autopsy studies), had a mean thickness of 2.47 mm and a mean length of 19.3 mm. In conclusion, autopsy studies should be the gold standard in evaluating the actual prevalence of myocardial bridges, while in vivo high-resolution CT scanning should be preferred to coronary angiography studies.
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Affiliation(s)
- Sorin Hostiuc
- Department of Legal Medicine and Bioethics, Faculty of Medicine, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania
| | - Ionuț Negoi
- Department of Surgery, Faculty of Medicine, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania, 042122
| | - Mugurel C Rusu
- Division of Anatomy, Faculty of Dental Medicine, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania, 020021.,MEDCENTER, Centre of Excellence in Laboratory Medicine and Pathology, Bucharest, Romania, 021021
| | - Mihaela Hostiuc
- Department of Internal Medicine and Gastroenterology, Faculty of Medicine, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania, 020021
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11
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Hou P, Feng X, Liu J, Zhou Y, Jiang Y, Jiang X, Gao J. Iterative reconstruction in single-source dual-energy CT angiography: feasibility of low and ultra-low volume contrast medium protocols. Br J Radiol 2017; 90:20160506. [PMID: 28555508 DOI: 10.1259/bjr.20160506] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE To evaluate the feasibility of using contrast medium (CM) of low and ultra-low volumes and injection rates in aortic CT angiography (CTA) through the joint application of single-source dual-energy CT (ssDECT) and adaptive statistical iterative reconstruction (ASIR). METHODS 120 patients with known or suspected aortic dissection underwent aortic CTA and were equally divided into 3 groups. Conventional 120-kVp scan with a CM volume of 70 ml and an injection rate of 5 ml s-1 was performed on Group A. Groups B and C underwent ssDECT scan with CM volumes of 0.6 and 0.4 ml kg-1, respectively. 40% and 50% ASIR algorithms were applied for Groups B and C, respectively. A five-point grading scheme was utilized to subjectively evaluate the image quality, and the CT value and contrast-to-noise ratio were recorded as objective measures. The radiation dose was also evaluated. RESULTS Groups B and C had equivalent subjective scores and CT values as Group A, whereas they had higher or equivalent contrast-to-noise ratios. Group B had 40.1% and 30% reductions on CM volume and injection rate, respectively, than Group A. Group C further resulted in 19.2% and 22% lesser CM volume and injection rate than Group B. The average effective radiation doses for the study groups were 22.5-24.5% lower than the control group. CONCLUSION With the aid of ASIR and ssDECT for aortic CTA, it is feasible to adopt low and ultra-low CM volumes and injection rates while obtaining good quality images. Advances in knowledge: Low and ultra-low CM volumes and injection rates are feasible in CTA through the joint application of ssDECT and ASIR.
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Affiliation(s)
- Ping Hou
- 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Xiangnan Feng
- 2 Department of Statistics, The Chinese University of Hong Kong, Hong Kong, China
| | - Jie Liu
- 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Yue Zhou
- 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Yaojun Jiang
- 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Xiaochen Jiang
- 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Jianbo Gao
- 1 Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
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A Comparison of the Image Quality and Radiation Dose With Routine Computed Tomography and the Latest Gemstone Spectral Imaging Combination of Different Scanning Protocols in Computed Tomography Angiography of the Kidney. J Comput Assist Tomogr 2017; 41:263-270. [PMID: 27824666 DOI: 10.1097/rct.0000000000000510] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The objective of our study was to compare the image quality and radiation dose of computed tomography angiography (CTA) of the kidney in patients with different body mass indexes using routine CT and the latest gemstone spectral imaging (GSI) combination of different scanning protocols with the adaptive statistical iterative reconstruction 2.0 algorithm. METHODS A total of 90 patients who had undergone a CTA of the kidney were divided into 3 groups (A, B, and C), with 30 patients in each group. Group A underwent a routine CT examination, whereas groups B and C underwent GSI with different scanning protocols. All images were restructured using the adaptive statistical iterative reconstruction 2.0. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of all images were calculated when the kidney CTA was completed. Each subjective image evaluation used a 5-point scoring method and was conducted by 2 independent radiologists. The CT dose index of volume and the dose-length product were recorded, and the mean value was calculated. The dose-length product was converted to the effective dose. All data were compared with a 1-way analysis of variance. RESULTS The SNR, CNR, and subjective image quality in group A were significantly lower than those in groups B and C (P < 0.01). There were no significant differences in SNR, CNR, and subjective image quality between groups B and C. The effective dose of group C decreased by 46.05% and 15.03% relative to those of groups A and B, respectively (P < 0.01). CONCLUSIONS The latest GSI with different scanning protocols can more effectively reduce the radiation dose than can the routine CT scan mode for a kidney CTA while still maintaining diagnostic image quality.
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CT angiography of the kidney using routine CT and the latest Gemstone Spectral Imaging combination of different noise indexes: image quality and radiation dose. Radiol Med 2017; 122:327-336. [DOI: 10.1007/s11547-017-0739-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 02/06/2017] [Indexed: 12/12/2022]
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Lador F, Hachulla AL, Hohn O, Plojoux J, Ronot M, Montet X, Soccal PM. Pulmonary Perfusion Changes as Assessed by Contrast-Enhanced Dual-Energy Computed Tomography after Endoscopic Lung Volume Reduction by Coils. Respiration 2016; 92:404-413. [PMID: 27820928 DOI: 10.1159/000452477] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 10/11/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Endoscopic lung volume reduction by coils (LVRC) is a recent treatment approach for severe emphysema. Furthermore, dual-energy computed tomography (DECT) now offers a combined assessment of lung morphology and pulmonary perfusion. OBJECTIVES The aim of our study was to assess the impact of LVRC on pulmonary perfusion with DECT. METHODS Seventeen patients (64.8 ± 6.7 years) underwent LVRC. DECT was performed prior to and after LVRC. For each patient, lung volumes and emphysema quantification were automatically calculated. Then, 6 regions of interest (ROIs) on the iodine perfusion map were drawn in the anterior, mid, and posterior right and left lungs at 4 defined levels. The ROI values were averaged to obtain lung perfusion as assessed by the lung's iodine concentration (CLung, μg·cm-3). The CLung values were normalized using the left atrial iodine concentration (CLA) to take into account differences between successive DECT scans. RESULTS The 6-min walk distance (6MWD) improved significantly after the procedure (p = 0.0002). No lung volume changes were observed between successive DECT scans for any of the patients (p = 0.32), attesting the same suspended inspiration. After LVRC, the emphysema index was significantly reduced in the treated lung (p = 0.0014). Lung perfusion increased significantly adjacent to the treated areas (CLung/CLA from 3.4 ± 1.7 to 5.6 ± 2.2, p < 0.001) and in the ipsilateral untreated areas (from 4.1 ± 1.4 to 6.6 ± 1.7, p < 0.001), corresponding to a mean 65 and 61% increase in perfusion, respectively. No significant difference was observed in the contralateral upper and lower areas (from 4.4 ± 1.9 to 4.8 ± 2.1, p = 0.273, and from 4.9 ± 2.0 to 5.2 ± 1.7, p = 0.412, respectively). A significant correlation between increased 6MWD and increased perfusion was found (p = 0.0027, R2 = 0.3850). CONCLUSIONS Quantitative analysis based on DECT acquisition revealed that LVRC results in a significant increase in perfusion in the coil-free areas adjacent to the treated ones, as well as in the ipsilateral untreated areas. This suggests a possible role for LVRC in the improvement of the ventilation/perfusion relationship.
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Affiliation(s)
- Frédéric Lador
- Service of Pulmonary Medicine, Geneva University Hospitals, Geneva, Switzerland
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Hachulla AL, Ronot M, Noble S, Becker CD, Montet X, Vallée JP. ECG-triggered high-pitch CT for simultaneous assessment of the aorta and coronary arteries. J Cardiovasc Comput Tomogr 2016; 10:407-13. [DOI: 10.1016/j.jcct.2016.07.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 07/10/2016] [Indexed: 12/21/2022]
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128-slice CT angiography of the aorta without ECG-gating: efficacy of faster gantry rotation time and iterative reconstruction in terms of image quality and radiation dose. Eur Radiol 2015; 26:359-69. [PMID: 26003792 DOI: 10.1007/s00330-015-3848-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 04/11/2015] [Accepted: 05/13/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To evaluate image quality and radiation dose of non ECG-gated 128-slice CT angiography of the aorta (CTAA) with fast gantry rotation time and iterative reconstruction. METHODS Four hundred and eighty patients underwent non ECG-gated CTAA. Qualitative and quantitative image quality assessments were performed. Radiation dose was assessed and compared with the dose of patients who underwent ECG-gated CTAA (n = 126) and the dose of previous CTAA performed with another CT (n = 339). RESULTS Image quality (aortic root-ascending portion) was average-to-excellent in more than 94% of cases, without any non-diagnostic scan. For proximal coronaries, image quality was average-to-excellent in more than 50%, with only 21.5% of non-diagnostic cases. Quantitative analysis results were also good. Mean radiation dose for thoracic CTAA was 5.6 mSv versus 20.6 mSv of ECG-gated protocol and 20.6 mSv of 16-slice CTAA scans, with an average dose reduction of 72.8% (p < 0.001). Mean radiation dose for thoracic-abdominal CTAA was 9.7 mSv, versus 20.9 mSv of 16-slice CTAA scans, with an average dose reduction of 53.6% (p < 0.001). CONCLUSIONS Non ECG-gated 128-slice CTAA is feasible and able to provide high quality visualization of the entire aorta without significant motion artefacts, together with a considerable dose and contrast media volume reduction. KEY POINTS • CT image quality of aortic root-ascending aorta is challenging. • Non ECG-gated scans are often limited by pulsatility artefacts. • ECG-gated examinations are usually limited by high radiation doses. • Non ECG-gated 128-slice low dose CTAA provides high quality images. • 128-slice CTAA low dose protocol could frequently replace ECG-gated CTAA.
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Ippolito D, Talei Franzesi C, Fior D, Bonaffini PA, Minutolo O, Sironi S. Low kV settings CT angiography (CTA) with low dose contrast medium volume protocol in the assessment of thoracic and abdominal aorta disease: a feasibility study. Br J Radiol 2015; 88:20140140. [PMID: 25784185 PMCID: PMC4628465 DOI: 10.1259/bjr.20140140] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE To assess the diagnostic quality of low dose (100 kV) CT angiography (CTA), by using ultra-low contrast medium volume (30 ml), for thoracic and abdominal aorta evaluation. METHODS 67 patients with thoracic or abdominal vascular disease underwent multidetector CT study using a 256 slice scanner, with low dose radiation protocol (automated tube current modulation, 100 kV) and low contrast medium volume (30 ml; 4 ml s(-1)). Density measurements were performed on ascending, arch, descending thoracic aorta, anonymous branch, abdominal aorta, and renal and common iliac arteries. Radiation dose exposure [dose-length product (DLP)] was calculated. A control group of 35 patients with thoracic or abdominal vascular disease were evaluated with standard CTA protocol (automated tube current modulation, 120 kV; contrast medium, 80 ml). RESULTS In all patients, we correctly visualized and evaluated main branches of the thoracic and abdominal aorta. No difference in density measurements was achieved between low tube voltage protocol (mean attenuation value of thoracic aorta, 304 HU; abdominal, 343 HU; renal arteries, 331 HU) and control group (mean attenuation value of thoracic aorta, 320 HU; abdominal, 339; renal arteries, 303 HU). Radiation dose exposure in low tube voltage protocol was significantly different between thoracic and abdominal low tube voltage studies (490 and 324 DLP, respectively) and the control group (thoracic DLP, 1032; abdomen, DLP 1078). CONCLUSION Low-tube-voltage protocol may provide a diagnostic performance comparable with that of the standard protocol, decreasing radiation dose exposure and contrast material volume amount. ADVANCES IN KNOWLEDGE Low-tube-voltage-setting protocol combined with ultra-low contrast agent volume (30 ml), by using new multidetector-row CT scanners, represents a feasible diagnostic tool to significantly reduce the radiation dose delivered to patients and to preserve renal function, while also maintaining adequate diagnostic quality images in assessment of aorta.
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Affiliation(s)
- D Ippolito
- Department of Diagnostic Radiology, San Gerardo Hospital, Monza, Italy
- School of Medicine, University of Milano-Bicocca, Monza, Italy
| | - C Talei Franzesi
- Department of Diagnostic Radiology, San Gerardo Hospital, Monza, Italy
- School of Medicine, University of Milano-Bicocca, Monza, Italy
| | - D Fior
- Department of Diagnostic Radiology, San Gerardo Hospital, Monza, Italy
- School of Medicine, University of Milano-Bicocca, Monza, Italy
| | - P A Bonaffini
- Department of Diagnostic Radiology, San Gerardo Hospital, Monza, Italy
- School of Medicine, University of Milano-Bicocca, Monza, Italy
| | - O Minutolo
- Department of Diagnostic Radiology, San Gerardo Hospital, Monza, Italy
- School of Medicine, University of Milano-Bicocca, Monza, Italy
| | - S Sironi
- Department of Diagnostic Radiology, San Gerardo Hospital, Monza, Italy
- School of Medicine, University of Milano-Bicocca, Monza, Italy
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Shen Y, Sun Z, Xu L, Li Y, Zhang N, Yan Z, Fan Z. High-pitch, low-voltage and low-iodine-concentration CT angiography of aorta: assessment of image quality and radiation dose with iterative reconstruction. PLoS One 2015; 10:e0117469. [PMID: 25643353 PMCID: PMC4314070 DOI: 10.1371/journal.pone.0117469] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 12/25/2014] [Indexed: 11/18/2022] Open
Abstract
Objective To assess the image quality of aorta obtained by dual-source computed tomography angiography (DSCTA), performed with high pitch, low tube voltage, and low iodine concentration contrast medium (CM) with images reconstructed using iterative reconstruction (IR). Methods One hundred patients randomly allocated to receive one of two types of CM underwent DSCTA with the electrocardiogram-triggered Flash protocol. In the low-iodine group, 50 patients received CM containing 270 mg I/mL and were scanned at low tube voltage (100 kVp). In the high-iodine CM group, 50 patients received CM containing 370 mg I/mL and were scanned at the tube voltage (120 kVp). The filtered back projection (FBP) algorithm was used for reconstruction in both groups. In addition, the IR algorithm was used in the low-iodine group. Image quality of the aorta was analyzed subjectively by a 3-point grading scale and objectively by measuring the CT attenuation in terms of the signal- and contrast-to-noise ratios (SNR and CNR, respectively). Radiation and CM doses were compared. Results The CT attenuation, subjective image quality assessment, SNR, and CNR of various aortic regions of interest did not differ significantly between two groups. In the low-iodine group, images reconstructed by FBP and IR demonstrated significant differences in image noise, SNR, and CNR (p<0.05). The low-iodine group resulted in 34.3% less radiation (4.4 ± 0.5 mSv) than the high-iodine group (6.7 ± 0.6 mSv), and 27.3% less iodine weight (20.36 ± 2.65 g) than the high-iodine group (28 ± 1.98 g). Observers exhibited excellent agreement on the aortic image quality scores (κ = 0.904). Conclusions CT images of aorta could be obtained within 2 s by using a DSCT Flash protocol with low tube voltage, IR, and low-iodine-concentration CM. Appropriate contrast enhancement was achieved while maintaining good image quality and decreasing the radiation and iodine doses.
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Affiliation(s)
- Yanguang Shen
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University—Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, China
- Department of Radiology, Hospital Affiliated to Hainan Medical College, Haikou, City of Hainan Province, China
| | - Zhonghua Sun
- Discipline of Medical Imaging, Department of Imaging and Applied Physics, Curtin University, Perth, Australia
| | - Lei Xu
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University—Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, China
| | - Yu Li
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University—Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, China
| | - Nan Zhang
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University—Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, China
| | - Zixu Yan
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University—Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, China
| | - Zhanming Fan
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University—Beijing Institute of Heart Lung and Blood Vessel Diseases, Beijing, China
- * E-mail:
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Multimodality Imaging of Diseases of the Thoracic Aorta in Adults: From the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr 2015; 28:119-82. [DOI: 10.1016/j.echo.2014.11.015] [Citation(s) in RCA: 409] [Impact Index Per Article: 45.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Liu Y, Xu J, Li J, Ren J, Liu H, Xu J, Wei M, Hao Y, Zheng M. The ascending aortic image quality and the whole aortic radiation dose of high-pitch dual-source CT angiography. J Cardiothorac Surg 2013; 8:228. [PMID: 24330784 PMCID: PMC4029485 DOI: 10.1186/1749-8090-8-228] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 12/09/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Aortic dissection is a lift-threatening medical emergency associated with high rates of morbidity and mortality. The incidence rate of aortic dissection is estimated at 5 to 30 per 1 million people per year. The prompt and correct diagnosis of aortic dissection is critical. This study was to compare the ascending aortic image quality and the whole aortic radiation dose of high-pitch dual-source CT angiography and conventional dual-source CT angiography. METHODS A total of 110 consecutive patients with suspected aortic dissection and other aortic disorders were randomly divided into two groups. Group A underwent traditional scan mode and Group B underwent high-pitch dual-source CT scan mode. The image quality and radiation dose of two groups were compared. RESULTS Close interobserver agreement was found for image quality scores (κ = 0.87). The image quality of ascending aorta was significantly better in the high-pitch group than in the conventional group (2.78 ± 0.46 vs 1.57 ± 0.43, P < 0.001). There was no significant difference of the CT attenuation values, the aortic image noise and SNR between two groups. The mean radiation dose of high-pitch group was also significantly lower than that of conventional group (2.7 ± 0.6 mSv vs. 3.9 ± 0.9 mSv, P < 0.001). CONCLUSIONS High-pitch dual-source CT angiography of the whole aorta can provide motion-artifact-free imaging of the ascending aorta at a low radiation dose compared to conventional protocol.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Minwen Zheng
- Department of Radiology, Xijing Hospital, Fourth Military Medical University, 169 West Changle Road, Xi'an 710032, China.
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Matsubara K, Koshida H, Sakuta K, Takata T, Horii J, Iida H, Koshida K, Ichikawa K, Matsui O. Radiation dose and physical image quality in 128-section dual-source computed tomographic coronary angiography: a phantom study. J Appl Clin Med Phys 2012; 13:3959. [PMID: 22955662 PMCID: PMC5718223 DOI: 10.1120/jacmp.v13i5.3959] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 06/11/2012] [Accepted: 06/07/2012] [Indexed: 12/01/2022] Open
Abstract
One‐hundred‐and‐twenty‐eight–section dual X‐ray source computed tomography (CT) systems have been introduced into clinical practice and have been shown to increase temporal resolution. Higher temporal resolution allows low‐dose spiral mode at a high pitch factor during CT coronary angiography. We evaluated radiation dose and physical image qualities in CT coronary angiography by applying high‐pitch spiral, step‐and‐shoot, and low‐pitch spiral modes to determine the optimal acquisition mode for clinical situations. An anthropomorphic phantom, small dosimeters, a calibration phantom, and a microdisc phantom were used to evaluate the radiation doses absorbed by thoracic organs, noise power spectrums, in‐plane and z‐axis modulation transfer functions, slice sensitivity profiles, and number of artifacts for the three acquisition modes. The high‐pitch spiral mode had the advantage of a small absorbed radiation dose, but provided low image quality. The low‐pitch spiral mode resulted in a high absorbed radiation dose of approximately 200 mGy for the heart. Although the absorbed radiation dose was lower in the step‐and‐shoot mode than in the low‐pitch spiral mode, the noise power spectrum was inferior. The quality of the in‐plane modulation transfer function differed, depending on spatial frequency. Therefore, the step‐and‐shoot mode should be applied initially because of its low absorbed radiation dose and superior image quality. PACS numbers: 87.57.‐s; 87.57.C‐; 87.57.cf; 87.57.cm; 87.57.cp; 87.57.Q‐; 87.57.qp; 87.57.uq
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Affiliation(s)
- Kosuke Matsubara
- Department of Quantum Medical Technology, Faculty of Health Sciences, Kanazawa University, Kanazawa, Japan.
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Li Y, Fan Z, Xu L, Yang L, Xin H, Zhang N, Zhang Z. Prospective ECG-gated 320-row CT angiography of the whole aorta and coronary arteries. Eur Radiol 2012; 22:2432-40. [DOI: 10.1007/s00330-012-2497-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 04/05/2012] [Indexed: 10/28/2022]
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Individually adapted coronary 64-slice CT angiography based on precontrast attenuation values, using different kVp and tube current settings: evaluation of image quality. Int J Cardiovasc Imaging 2011; 27 Suppl 1:53-9. [PMID: 22005891 DOI: 10.1007/s10554-011-9960-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Accepted: 10/07/2011] [Indexed: 10/16/2022]
Abstract
To evaluate the feasibility of an individually adapted coronary CT protocol based on precontrast attenuation values using different kVp and tube current settings. All images were acquired on a 64-slice CT scanner (Sensation 64, Siemens) in 270 consecutive patients. X-ray tube current and kVp settings were defined in 6 groups depending on the noise measurements at the heart level on pre-control unenhanced CT. The contrast medium was 400 mg/ml of iodine given at 1 ml/kg. The duration of injection was at 17 s in all cases, so the flow rate was adapted accordingly. Contrast enhancement and noise were measured from enhanced scans of the aortic root. The contrast to noise ratio (CNR) was used as an indicator of image quality. The mean contrast enhancement was 391 ± 83 HU. The mean radiation dose was 9.4 mSv (1.4-30.4 mSv). The mean noise was 39.8 ± 7.7 HU; noise was not significantly different between the groups, except for the 80 kVp group (mean noise = 54.5 HU, P < 0.05). The mean CNR was 10.1 ± 2.5, and CNR was similar in groups 1, 3, 4, and 5 (scanned at 80 kVp or 120 kVp), but significantly higher (CNR = 12) in group 2 (100 kVp) and significantly lower (CNR = 7.9) in group 6 (140 kVp). Individual adaptation of radiation dose is feasible in routine clinical coronary multislice CT, at various kVp and mAs settings. Image quality may be preserved with substantial radiation dose savings in patients with low attenuation values on precontrast images.
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Subtraction Coronary CT Angiography for the Evaluation of Severely Calcified Lesions Using a 320-Detector Row Scanner. CURRENT CARDIOVASCULAR IMAGING REPORTS 2011. [DOI: 10.1007/s12410-011-9108-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Schernthaner RE, Stadler A, Beitzke D, Homolka P, Weber M, Lammer J, Czerny M, Loewe C. Dose modulated retrospective ECG-gated versus non-gated 64-row CT angiography of the aorta at the same radiation dose: comparison of motion artifacts, diagnostic confidence and signal-to-noise-ratios. Eur J Radiol 2011; 81:e585-90. [PMID: 21820829 DOI: 10.1016/j.ejrad.2011.06.053] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 06/23/2011] [Accepted: 06/27/2011] [Indexed: 11/17/2022]
Abstract
PURPOSE To compare ECG-gated and non-gated CT angiography of the aorta at the same radiation dose, with regard to motion artifacts (MA), diagnostic confidence (DC) and signal-to-noise-ratios (SNRs). MATERIALS AND METHODS Sixty consecutive patients prospectively randomized into two groups underwent 64-row CT angiography, with or without dose-modulated ECG-gating, of the entire aorta, due to several pathologies of the ascending aorta. MA and DC were both assessed using a four-point scale. SNRs were calculated by dividing the mean enhancement by the standard deviation. The dose-length-product (DLP) of each examination was recorded and the effective dose was estimated. RESULTS Dose-modulated ECG-gating showed statistically significant advantages over non-gated CT angiography, with regard to MA (p<0.001) and DC (p<0.001), at the aortic valve, at the origin of the coronary arteries, and at the dissection membrane, with a significant correlation (p<0.001) between MA and DC. At the aortic wall, however, ECG-gated CT angiography showed statistically significant fewer MA (p<0.001), but not a statistically significant higher DC (p=0.137) compared to non-gated CT angiography. At the supra-aortic vessels and the descending aorta, the ECG-triggering showed no statistically significant differences with regard to MA (p=0.861 and 0.526, respectively) and DC (p=1.88 and 0.728, respectively). The effective dose of ECG-gated CT angiography (23.24mSv; range, 18.43-25.94mSv) did not differ significantly (p=0.051) from that of non-gated CT angiography (24.28mSv; range, 19.37-29.27mSv). CONCLUSION ECG-gated CT angiography of the entire aorta reduces MA and results in a higher DC with the same SNR, compared to non-gated CT angiography at the same radiation dose.
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Yang L, Xu L, Yan Z, Yu W, Fan Z, Lv B, Zhang Z. Low dose 320-row CT for left atrium and pulmonary veins imaging--the feasibility study. Eur J Radiol 2011; 81:1549-54. [PMID: 21392909 DOI: 10.1016/j.ejrad.2011.02.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 02/01/2011] [Accepted: 02/07/2011] [Indexed: 12/29/2022]
Abstract
OBJECTIVE To evaluate the feasibility of low dose target-CTA volume scan for left atrium and pulmonary veins imaging using 320-row CT. METHODS Forty-two patients (females 12, males 30; mean age 55.2 years; mean body mass index (BMI) 25.7 kg/m(2)) with persistent or intermittent atrial fibrillation before catheter ablation were enrolled in this study. Scan protocol was target-CTA volume scan under prospective ECG-gating. The target of the exposure was only set at 40% of the R-R interval (which was at the left atrium maximal volume). The exposure time was minimal setting (350 ms). Tube voltage 100 kV (BMI ≤ 25 kg/m(2)) or 120 kV (BMI>25 kg/m(2)), tube current 350-420 mA, and field of view of 180 mm × 180 mm-200 mm × 200 mm were used. The scanning range was from the level of the tracheal bifurcation to the diaphragm, and enabled to cover the left atrium and central pulmonary veins (120-140 mm). All of patients were divided into two groups according kV setting (100 kV and 120 kV). The image quality (good, moderate and poor) was evaluated by two reviewers. The CT-attenuation, image noise and contrast to noise ratio (CNR) of left atrium and every pulmonary vein branch were evaluated, respectively. The effective dose (ED) was calculated using a conversion coefficient for the chest 0.017. RESULTS Of 42 patients, the image quality was good in 26 cases (62%) and moderate in 16 cases (38%). There was no statistical difference in the CT-attenuation and CNR of left atrium and central pulmonary veins between the two groups (P>0.05). The mean ED was 1.90 ± 0.19 mSv (range 1.57-2.25 mSv) in 100 kV group, and 3.83 ± 0.31 mSv (range 3.39-4.54 mSv) in 120 kV group. CONCLUSIONS The low dose target-CTA volume scan is feasible in pulmonary veins and left atrium imaging using 320-row CT. Slim patients can be scanned at 100 kV setting without loss of image quality.
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Affiliation(s)
- Lin Yang
- Department of Radiology, An Zhen Hospital, Capital Medical University, An Zhen Li, Beijing 100029, China
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Added value of CT in adult congenital heart disease. CURRENT CARDIOVASCULAR IMAGING REPORTS 2009. [DOI: 10.1007/s12410-009-0057-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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