1
|
Klemenz AC, Albrecht L, Manzke M, Dalmer A, Böttcher B, Surov A, Weber MA, Meinel FG. Improved image quality in CT pulmonary angiography using deep learning-based image reconstruction. Sci Rep 2024; 14:2494. [PMID: 38291105 PMCID: PMC10827738 DOI: 10.1038/s41598-024-52517-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 01/19/2024] [Indexed: 02/01/2024] Open
Abstract
We investigated the effect of deep learning-based image reconstruction (DLIR) compared to iterative reconstruction on image quality in CT pulmonary angiography (CTPA) for suspected pulmonary embolism (PE). For 220 patients with suspected PE, CTPA studies were reconstructed using filtered back projection (FBP), adaptive statistical iterative reconstruction (ASiR-V 30%, 60% and 90%) and DLIR (low, medium and high strength). Contrast-to-noise ratio (CNR) served as the primary parameter of objective image quality. Subgroup analyses were performed for normal weight, overweight and obese individuals. For patients with confirmed PE (n = 40), we further measured PE-specific CNR. Subjective image quality was assessed independently by two experienced radiologists. CNR was lowest for FBP and enhanced with increasing levels of ASiR-V and, even more with increasing strength of DLIR. High strength DLIR resulted in an additional improvement in CNR by 29-67% compared to ASiR-V 90% (p < 0.05). PE-specific CNR increased by 75% compared to ASiR-V 90% (p < 0.05). Subjective image quality was significantly higher for medium and high strength DLIR compared to all other image reconstructions (p < 0.05). In CT pulmonary angiography, DLIR significantly outperforms iterative reconstruction for increasing objective and subjective image quality. This may allow for further reductions in radiation exposure in suspected PE.
Collapse
Affiliation(s)
- Ann-Christin Klemenz
- Institute of Diagnostic and Interventional Radiology, Pediatric Radiology and Neuroradiology, University Medical Centre Rostock, Schillingallee 36, 18057, Rostock, Germany
| | - Lasse Albrecht
- Institute of Diagnostic and Interventional Radiology, Pediatric Radiology and Neuroradiology, University Medical Centre Rostock, Schillingallee 36, 18057, Rostock, Germany
| | - Mathias Manzke
- Institute of Diagnostic and Interventional Radiology, Pediatric Radiology and Neuroradiology, University Medical Centre Rostock, Schillingallee 36, 18057, Rostock, Germany
| | - Antonia Dalmer
- Institute of Diagnostic and Interventional Radiology, Pediatric Radiology and Neuroradiology, University Medical Centre Rostock, Schillingallee 36, 18057, Rostock, Germany
| | - Benjamin Böttcher
- Institute of Diagnostic and Interventional Radiology, Pediatric Radiology and Neuroradiology, University Medical Centre Rostock, Schillingallee 36, 18057, Rostock, Germany
| | - Alexey Surov
- Department of Radiology, Mühlenkreiskliniken Minden, Ruhr-University Bochum, Bochum, Germany
| | - Marc-André Weber
- Institute of Diagnostic and Interventional Radiology, Pediatric Radiology and Neuroradiology, University Medical Centre Rostock, Schillingallee 36, 18057, Rostock, Germany
| | - Felix G Meinel
- Institute of Diagnostic and Interventional Radiology, Pediatric Radiology and Neuroradiology, University Medical Centre Rostock, Schillingallee 36, 18057, Rostock, Germany.
| |
Collapse
|
2
|
Park MS, Ha HI, Ahn JH, Lee IJ, Lim HK. Reducing contrast-agent volume and radiation dose in CT with 90-kVp tube voltage, high tube current modulation, and advanced iteration algorithm. PLoS One 2023; 18:e0287214. [PMID: 37319309 PMCID: PMC10270572 DOI: 10.1371/journal.pone.0287214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 05/31/2023] [Indexed: 06/17/2023] Open
Abstract
Increasing utilization of computed tomography (CT) has raised concerns regarding CT radiation dose and technology has been developed to achieve an appropriate balance between image quality, radiation dose, and the amount of contrast material. This study was planned to evaluate the image quality and radiation dose in pancreatic dynamic computed tomography (PDCT) with 90-kVp tube voltage and reduction of the standard amount of contrast agent, compared with 100-kVp PDCT of the research hospital's convention. Total of 51 patients with both CT protocols were included. The average Hounsfield units (HU) values of the abdominal organs and image noise were measured for objective image quality analysis. Two radiologists evaluated five categories of image qualities such as subjective image noise, visibility of small structure, beam hardening or streak artifact, lesion conspicuity and overall diagnostic performance for subjective image quality analysis. The total amount of contrast agent, radiation dose, and image noise decreased in the low-kVp group, by 24.4%, 31.7%, and 20.6%, respectively (p < 0.001). The intraobserver and interobserver agreements were moderate to substantial (k = 0.4-0.8). The contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and figure of merit of the almost organs except psoas muscle in the low-kVp group were significantly higher (p < 0.001). Except for lesion conspicuity, both reviewers judged that subjective image quality of the 90-kVp group was better (p < 0.001). With 90-kVp tube voltage, 25% reduced contrast agent volume with advanced iteration algorithm and high tube current modulation achieved radiation dose reduction of 31.7%, as well as better image quality and diagnostic confidence.
Collapse
Affiliation(s)
- Min Su Park
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang-si, Gyeonggi-do, Republic of Korea
| | - Hong Il Ha
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang-si, Gyeonggi-do, Republic of Korea
| | - Jhii-Hyun Ahn
- Department of Radiology, Yonsei University Wonju College of Medicine, Wonju Severance Christian Hospital, Wonju, Gangwon-do, Republic of Korea
| | - In Jae Lee
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang-si, Gyeonggi-do, Republic of Korea
| | - Hyun Kyung Lim
- Department of Radiology, Soonchunhyang University Seoul Hospital, Seoul, Republic of Korea
| |
Collapse
|
3
|
Hee Kim K, Choo KS, Jin Nam K, Lee K, Hwang JY, Park C, Jung Yang W. Cardiac CTA image quality of adaptive statistical iterative reconstruction-V versus deep learning reconstruction "TrueFidelity" in children with congenital heart disease. Medicine (Baltimore) 2022; 101:e31169. [PMID: 36281124 PMCID: PMC9592454 DOI: 10.1097/md.0000000000031169] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Several recent studies have reported that deep learning reconstruction "TrueFidelity" (TF) improves computed tomography (CT) image quality. However, no study has compared adaptive statistical repeated reconstruction (ASIR-V) using TF in pediatric cardiac CT angiography (CTA) with a low peak kilovoltage. OBJECTIVE This study aimed to determine whether ASIR-V or TF CTA image quality is superior in children with congenital heart disease (CHD). MATERIALS AND METHODS Fifty children (median age, 2 months; interquartile range, 0-5 months; 28 men) with CHD who underwent CTA were enrolled between June and September 2020. Images were reconstructed using 2 ASIR-V blending factors (80% and 100% [AV-100]) and 3 TF settings (low, medium, and high [TF-H] strength levels). For the quantitative analyses, 3 objective image qualities (attenuation, noise, and signal-to-noise ratio [SNR]) were measured of the great vessels and heart chambers. The contrast-to-noise ratio (CNR) was also evaluated between the left ventricle and the dial wall. For the qualitative analyses, the degree of quantum mottle and blurring at the upper level to the first branch of the main pulmonary artery was assessed independently by 2 radiologists. RESULTS When the ASIR-V blending factor level and TF strength were higher, the noise was lower, and the SNR was higher. The image noise and SNR of TF-H were significantly lower and higher than those of AV-100 (P < .01), except for noise in the right atrium and left pulmonary artery and SNR of the right ventricle. Regarding CNR, TF-H was significantly better than AV-100 (P < .01). In addition, in the objective assessment of the degree of quantum mottle and blurring, TF-H had the best score among all examined image sets (P < .01). CONCLUSION TF-H is superior to AV-100 in terms of objective and subjective image quality. Consequently, TF-H was the best image set for cardiac CTA in children with CHD.
Collapse
Affiliation(s)
- Kun Hee Kim
- Department of Radiology, Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan-si, Gyeongsangnam-do, Korea
| | - Ki Seok Choo
- Department of Radiology, Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan-si, Gyeongsangnam-do, Korea
- *Correspondence: Ki Seok Choo, Department of Radiology, Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Beomeo-RI, Mulgeum-eup, Yangsan-si, Gyeongsangnam-do, 626-770, Korea (e-mail: )
| | - Kyoung Jin Nam
- Department of Radiology, Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan-si, Gyeongsangnam-do, Korea
| | - Kyeyoung Lee
- Department of Radiology, Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan-si, Gyeongsangnam-do, Korea
| | - Jae-Yeon Hwang
- Department of Radiology, Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan-si, Gyeongsangnam-do, Korea
| | - ChanKue Park
- Department of Radiology, Pusan National University School of Medicine and Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan-si, Gyeongsangnam-do, Korea
| | - Woo Jung Yang
- Barunmom Rehabilitation Medicine, Busanjin-gu, Busan, Korea
| |
Collapse
|
4
|
Feasibility of Deep Learning-Based Noise and Artifact Reduction in Coronal Reformation of Contrast-Enhanced Chest Computed Tomography. J Comput Assist Tomogr 2022; 46:593-603. [PMID: 35617647 DOI: 10.1097/rct.0000000000001326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE This study aimed to evaluate the feasibility of a deep learning method for imaging artifact and noise reduction in coronal reformation of contrast-enhanced chest computed tomography (CT). METHODS A total of 19,052 coronal reformatted chest CT images of 110 CT image sets (55 pairs of concordant 16- and 320-row CT image sets) were included and used to train a deep learning algorithm for artifact and noise correction. For internal validation, 4093 coronal reformatted CT images of 25 patients from 16-row CT images underwent correction processing. For external validation, chest CT images of 30 patients (1028 coronal reformatted CT images), acquired in other institutions using different scanners, were subjected to correction processing. For both validations, image quality was compared between original ("CTorigin") and deep learning-based corrected ("CTcorrect") CT images. Quantitative analysis for stair-step artifact (coefficient of variance of CT density on coronal reformation), image noise, signal-to-noise ratio, and contrast-to-noise ratio were evaluated. Subjective image quality scores were assigned for image contrast, artifact, and conspicuity of major structures. RESULTS CTcorrect showed significantly reduced stair-step artifact (mean coefficient of variance: CTorigin 7.35 ± 2.0 vs CTcorrect 5.17 ± 2.4, P < 0.001) and image noise and improved signal-to-noise ratio and contrast-to-noise ratio in the aorta, pulmonary artery, and liver, compared with those of CTorigin (P < 0.01). On subjective analysis, CTcorrect had higher image contrast, lower artifact, and better conspicuity than CTorigin. Most results of the external validation were consistent with those obtained from the internal validation, except for those concerning the pulmonary artery. CONCLUSIONS Deep learning-based artifact correction significantly improved the image quality of coronal reformation chest CT by reducing image noise and artifacts.
Collapse
|
5
|
Evaluation of Abdominal CT Obtained Using a Deep Learning-Based Image Reconstruction Engine Compared with CT Using Adaptive Statistical Iterative Reconstruction. J Belg Soc Radiol 2022; 106:15. [PMID: 35480337 PMCID: PMC8992765 DOI: 10.5334/jbsr.2638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 03/24/2022] [Indexed: 11/20/2022] Open
Abstract
Purpose: Materials and Methods: Results: Conclusions:
Collapse
|
6
|
Zhang X, Chen J, Yu N, Ren Z, Tian Q, Tian X, Jia Y, He T, Guo C. Reducing contrast medium dose with low photon energy images in renal dual-energy spectral CT angiography and adaptive statistical iterative reconstruction (ASIR). Br J Radiol 2021; 94:20200974. [PMID: 33684310 DOI: 10.1259/bjr.20200974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To evaluate the value of using low energy (keV) images in renal dual-energy spectral CT angiography (CTA) and adaptive statistical iterative reconstruction (ASIR) to reduce contrast medium dose. METHODS 40 patients with renal CTA on a Discovery CT750HD were randomly divided into two groups: 20 cases (Group A) with 600 mgI kg-1 and 20 cases (Group B) with 300 mgI kg-1. The scan protocol for both groups was: dual-energy mode with mA selection for noise index of 10 HU, pitch 1.375:1, rotating speed 0.6 s/r. Images were reconstructed at 0.625 mm thickness with 40%ASIR, Group A used the conventional 70keV monochromatic images, and Group B used monochromatic images from 40 to 70 keV at 5 keV interval for analysis. The CT values and standard deviation (SD) values of the renal artery and erector spine in the plain and arterial phases were measured with the erector spine SD value representing image noise. The enhancement degree of the renal artery (ΔCT = CT(arterial) -CT(plain)), signal-to-noise ratio (SNR=CTrenal-artery/SDrenal-artery) and contrast-to-noise ratio (CNR=(CTrenal-artery-CTerector spine)/SDerector-spine) were calculated. The single factor analysis of variance was used to analyze the difference of ΔCT, SNR and CNR among image groups with p < 0.05 being statistically significant. The subjective image scores of the groups were assessed blindly by two experienced physicians using a 5-point system and the score consistency was compared by the κ test. RESULTS Contrast medium dose in the 300 mgI kg-1 group was reduced by 50% compared with the 600 mgI kg-1 group, while radiation dose was similar between the two groups. The subjective scores were 4.00 ± 0.65, 4.50 ± 0.60 and 3.70 ± 0.80 for images at 70 keV (600 mgI kg-1 group), 40 keV (300 mgI kg-1 group) and 45 keV (300 mgI kg-1 group), respectively with good consistency between the two reviewers (p > 0.05). The 40 keV images in the 300 mgI kg-1 group had similar ΔCT (469.77 ± 86.95 HU vs 398.54 ± 73.68 HU) and CNR (15.52 ± 3.32 vs 18.78 ± 6.71) values as the 70 keV images in the 600 mgI kg-1) group but higher SNR values (30.19 ± 4.41 vs 16.91 ± 11.12, p < 0,05). CONCLUSION Contrast dose may be reduced by 50% while maintaining image quality by using lower energy images combined with ASIR in renal dual-energy CTA. ADVANCES IN KNOWLEDGE Combined with ASIR and energy spectrum, can reduce the amount of contrast dose in renal CTA.
Collapse
Affiliation(s)
- Xirong Zhang
- Department of Medical Techniques, Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, The Second Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China
| | - Jing Chen
- Department of Medical Techniques, Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, The Second Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China
| | - Nan Yu
- Department of Medical Techniques, Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, The Second Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China
| | - Zhanli Ren
- Department of Medical Techniques, Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, The Second Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China
| | - Qian Tian
- Department of Medical Techniques, Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, The Second Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China
| | - Xin Tian
- Department of Medical Techniques, Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, The Second Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China
| | - Yongjun Jia
- Department of Medical Techniques, Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, The Second Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China
| | - Taiping He
- Department of Medical Techniques, Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, The Second Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China
| | - Changyi Guo
- Department of Medical Techniques, Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China.,Department of Radiology, The Second Affiliated Hospital of Shaanxi University of Chinese medicine, Xianyang, China
| |
Collapse
|
7
|
Nguyen ET, Hague C, Manos D, Memauri B, Souza C, Taylor J, Dennie C. Canadian Society of Thoracic Radiology/Canadian Association of Radiologists Best Practice Guidance for Investigation of Acute Pulmonary Embolism, Part 1: Acquisition and Safety Considerations. Can Assoc Radiol J 2021; 73:203-213. [PMID: 33781098 DOI: 10.1177/08465371211000737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Acute pulmonary embolism (APE) is a well-recognized cause of circulatory system compromise and even demise which can frequently present a diagnostic challenge for the physician. The diagnostic challenge is primarily due to the frequency of indeterminate presentations as well as several other conditions which can have a similar clinical presentation. This often obliges the physician to establish a firm diagnosis due to the potentially serious outcomes related to this disease. Computed tomography pulmonary angiography (CTPA) has increasingly cemented its role as the primary investigation tool in this clinical context and is widely accepted as the standard of care due to several desired attributes which include great accuracy, accessibility, rapid turn-around time and the ability to suggest an alternate diagnosis when APE is not the culprit. In Part 1 of this guidance document, a series of up-to-date recommendations are provided to the reader pertaining to CTPA protocol optimization (including scan range, radiation and intravenous contrast dose), safety measures including the departure from breast and gonadal shielding, population-specific scenarios (pregnancy and early post-partum) and consideration of alternate diagnostic techniques when clinically deemed appropriate.
Collapse
Affiliation(s)
- Elsie T Nguyen
- Department of Radiology, Joint Department of Medical Imaging, Toronto General Hospital, University of Toronto, Ontario, Canada
| | - Cameron Hague
- Department of Radiology, University of British Columbia, Ontario, Canada
| | - Daria Manos
- Department of Diagnostic Radiology, Dalhousie University, Ontario, Canada
| | - Brett Memauri
- Department of Radiology, University of Manitoba, Cardiothoracic Sciences Division, St. Boniface General Hospital, Ontario, Canada
| | - Carolina Souza
- Department of Medical Imaging, The Ottawa Hospital, University of Ottawa, Ontario, Canada
| | - Jana Taylor
- Department of Radiology, McGill University Health Centre, Ontario, Canada
| | - Carole Dennie
- Department of Medical Imaging, The Ottawa Hospital, University of Ottawa, Ontario, Canada.,Department of Radiology, University of Ottawa, Ottawa Hospital Research Institute, Ontario, Canada
| |
Collapse
|
8
|
CT iterative vs deep learning reconstruction: comparison of noise and sharpness. Eur Radiol 2020; 31:3156-3164. [PMID: 33057781 DOI: 10.1007/s00330-020-07358-8] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/26/2020] [Accepted: 09/25/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVES To compare image noise and sharpness of vessels, liver, and muscle in lower extremity CT angiography between "adaptive statistical iterative reconstruction-V" (ASIR-V) and deep learning reconstruction "TrueFidelity" (TFI). METHODS Thirty-seven patients (mean age, 65.2 years; 32 men) with lower extremity CT angiography were enrolled between November and December 2019. Images were reconstructed with two ASIR-V (blending factor of 80% and 100% (AV-100)) and three TFI (low-, medium-, and high-strength-level (TF-H) settings). Two radiologists evaluated these images for vessels (aorta, femoral artery, and popliteal artery), liver, and psoas muscle. For quantitative analyses, conventional indicators (CT number, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR)) and blur metric values (indicating the degree of image sharpness) of selected regions of interest were determined. For qualitative analyses, the degrees of quantum mottle and blurring were assessed. RESULTS The higher the blending factor in ASIR-V or the strength in TFI, the lower the noise, the higher the SNR and CNR values, and the higher the blur metric values in all structures. The SNR and CNR values of TF-H images were significantly higher than those of AV-80 images and similar to those of AV-100 images. The blur metric values in TFI images were significantly lower than those in ASIR-V images (p < 0.001), indicating increased sharpness. Among all the investigated image procedures, the overall qualitative image quality was best in TF-H images. CONCLUSION TF-H was the most balanced image in terms of image noise and sharpness among the examined image combinations. KEY POINTS • Deep learning image reconstruction "TrueFidelity" is superior to iterative reconstruction "ASIR-V" regarding image noise and sharpness. • The high-strength "TrueFidelity" approach generated the best image quality among the examined image reconstruction procedures. • In iterative and deep learning CT image reconstruction, the higher the blending and strength factors, the lower the image noise and the poorer the image sharpness.
Collapse
|
9
|
Chu JS, Wang ZJ. Protocol Optimization for Renal Mass Detection and Characterization. Radiol Clin North Am 2020; 58:851-873. [PMID: 32792119 DOI: 10.1016/j.rcl.2020.05.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Renal masses increasingly are found incidentally, largely due to the frequent use of medical imaging. Computed tomography (CT) and MR imaging are mainstays for renal mass characterization, presurgical planning of renal tumors, and surveillance after surgery or systemic therapy for advanced renal cell carcinomas. CT protocols should be tailored to different clinical indications, balancing diagnostic accuracy and radiation exposure. MR imaging protocols should take advantage of the improved soft tissue contrast for renal tumor diagnosis and staging. Optimized imaging protocols enable analysis of imaging features that help narrow the differential diagnoses and guide management in patients with renal masses.
Collapse
Affiliation(s)
- Jason S Chu
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Avenue, Box 0628, San Francisco, CA 94143, USA
| | - Zhen J Wang
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Avenue, Box 0628, San Francisco, CA 94143, USA.
| |
Collapse
|
10
|
Deep Learning Versus Iterative Reconstruction for CT Pulmonary Angiography in the Emergency Setting: Improved Image Quality and Reduced Radiation Dose. Diagnostics (Basel) 2020; 10:diagnostics10080558. [PMID: 32759874 PMCID: PMC7460033 DOI: 10.3390/diagnostics10080558] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/01/2020] [Accepted: 08/02/2020] [Indexed: 12/13/2022] Open
Abstract
To compare image quality and the radiation dose of computed tomography pulmonary angiography (CTPA) subjected to the first deep learning-based image reconstruction (DLR) (50%) algorithm, with images subjected to the hybrid-iterative reconstruction (IR) technique (50%). One hundred forty patients who underwent CTPA for suspected pulmonary embolism (PE) between 2018 and 2019 were retrospectively reviewed. Image quality was assessed quantitatively (image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR)) and qualitatively (on a 5-point scale). Radiation dose parameters (CT dose index, CTDIvol; and dose-length product, DLP) were also recorded. Ninety-three patients were finally analyzed, 48 with hybrid-IR and 45 with DLR images. The image noise was significantly lower and the SNR (24.4 ± 5.9 vs. 20.7 ± 6.1) and CNR (21.8 ± 5.8 vs. 18.6 ± 6.0) were significantly higher on DLR than hybrid-IR images (p < 0.01). DLR images received a significantly higher score than hybrid-IR images for image quality, with both soft (4.4 ± 0.7 vs. 3.8 ± 0.8) and lung (4.1 ± 0.7 vs. 3.6 ± 0.9) filters (p < 0.01). No difference in diagnostic confidence level for PE between both techniques was found. CTDIvol (4.8 ± 1.4 vs. 4.0 ± 1.2 mGy) and DLP (157.9 ± 44.9 vs. 130.8 ± 41.2 mGy∙cm) were lower on DLR than hybrid-IR images. DLR both significantly improved the image quality and reduced the radiation dose of CTPA examinations as compared to the hybrid-IR technique.
Collapse
|
11
|
Abstract
OBJECTIVE. Pediatric CT angiography (CTA) presents unique challenges compared with adult CTA. Because of the ionizing radiation exposure, CTA should be used judiciously in children. The pearls offered here are observations gleaned from the authors' experience in the use of pediatric CTA. We also present some potential follies to be avoided. CONCLUSION. Understanding the underlying principles and paying meticulous attention to detail can substantially optimize dose and improve the diagnostic quality of pediatric CTA.
Collapse
|
12
|
Wu H, Chen X, Zhou H, Qin B, Cao J, Pan Z, Wang Z. An optimized test bolus for computed tomography pulmonary angiography and its application at 80 kV with 10 ml contrast agent. Sci Rep 2020; 10:10208. [PMID: 32576901 PMCID: PMC7311447 DOI: 10.1038/s41598-020-67145-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 05/04/2020] [Indexed: 01/31/2023] Open
Abstract
Computed tomography pulmonary angiography (CTPA) is usually used for pulmonary embolism (PE) detection. However, the determination of scan timing remains a challenge due to the short scan duration of CTPA. We aimed to develop an optimized test bolus to determine scan delay in CTPA. The time-enhancement curves were obtained by measuring the enhancement within a region of interest in the main pulmonary artery and vein. A total of 70 patients were randomly divided into two groups (n = 35 each): the control group underwent CTPA using the test bolus approach and the test group underwent CTPA using the biphasic time-enhancement curves approach. Tube voltages of 100 kVp and 80 kVp and 20 ml and 10 ml contrast agent were adopted in the control and test groups, respectively. The CT numbers, image quality, PE detection was evaluated. There was a point of intersection between the pulmonary artery and vein test bolus enhancement curves. The scan delay time (TDELAY) was obtained based on the time at intersection (TCROSS) and the scan duration (TSD): TDELAY = TCROSS − TSD. The mean CT numbers for pulmonary vein in the control were higher than those in the test group (all p < 0.001). The image quality for the pulmonary arteries in the test group was better than that in the control group (p < 0.01), with artifact reduction in the superior vena cava. Segmental PE could be detected using the optimized protocol. The radiation dose and iodine load in the test group were all lower than those in the control (p < 0.01). We established an approach to calculate the scan delay of CTPA, and this approach could be used for CTPA at 80 kVp with 10 ml contrast agent.
Collapse
Affiliation(s)
- Huiming Wu
- Department of Radiology, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Xiao Chen
- Department of Radiology, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Hao Zhou
- Department of Radiology, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Bin Qin
- Department of Radiology, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Jian Cao
- Department of Radiology, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Zhaochun Pan
- Department of Radiology, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Zhongqiu Wang
- Department of Radiology, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China.
| |
Collapse
|
13
|
Image reconstruction: Part 1 – understanding filtered back projection, noise and image acquisition. J Cardiovasc Comput Tomogr 2020; 14:219-225. [DOI: 10.1016/j.jcct.2019.04.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/04/2019] [Accepted: 04/15/2019] [Indexed: 11/23/2022]
|
14
|
Application of Artificial Intelligence–based Image Optimization for Computed Tomography Angiography of the Aorta With Low Tube Voltage and Reduced Contrast Medium Volume. J Thorac Imaging 2019; 34:393-399. [DOI: 10.1097/rti.0000000000000438] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
15
|
Hendriks BMF, Schnerr RS, Milanese G, Jeukens CRLPN, Niesen S, Eijsvoogel NG, Wildberger JE, Das M. Computed Tomography Pulmonary Angiography during Pregnancy: Radiation Dose of Commonly Used Protocols and the Effect of Scan Length Optimization. Korean J Radiol 2019; 20:313-322. [PMID: 30672171 PMCID: PMC6342764 DOI: 10.3348/kjr.2017.0779] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 07/24/2018] [Indexed: 01/21/2023] Open
Abstract
Objective To evaluate the radiation dose for pregnant women and fetuses undergoing commonly used computed tomography of the pulmonary arteries (CTPA) scan protocols and subsequently evaluate the simulated effect of an optimized scan length. Materials and Methods A total of 120 CTPA datasets were acquired using four distinctive scan protocols, with 30 patients per protocol. These datasets were mapped to Cristy phantoms in order to simulate pregnancy and to assess the effect of an effective radiation dose (in mSv) in the first, second, or third trimester of pregnancy, including a simulation of fetal dose in second and third trimesters. The investigated scan protocols involved a 64-slice helical scan at 120 kVp, a high-pitch dual source acquisition at 100 kVp, a dual-energy acquisition at 80/140 kVp, and an automated-kV-selection, high pitch helical scan at a reference kV of 100 kVref. The effective dose for women and fetuses was simulated before and after scan length adaptation. The original images were interpreted before and after scan length adaptations to evaluate potentially missed diagnoses. Results Large inter-scanner and inter-protocol variations were found; application of the latest technology decreased the dose for non-pregnant women by 69% (7.0–2.2 mSv). Individual scan length optimization proved safe and effective, decreasing the fetal dose by 76–83%. Nineteen (16%) cases of pulmonary embolism were diagnosed and, after scan length optimization, none were missed. Conclusion Careful CTPA scan protocol selection and additional optimization of scan length may result in significant radiation dose reduction for a pregnant patient and her fetus, whilst maintaining diagnostic confidence.
Collapse
Affiliation(s)
- Babs M F Hendriks
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands.,CARIM School for Cardiovascular Diseases, Maastricht University Medical Centre, Maastricht, The Netherlands.
| | - Roald S Schnerr
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Gianluca Milanese
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands.,Department of Surgical Sciences, Division of Radiology, University of Parma, Parma, Italy
| | - Cécile R L P N Jeukens
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Sandra Niesen
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Nienke G Eijsvoogel
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands.,CARIM School for Cardiovascular Diseases, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Joachim E Wildberger
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands.,CARIM School for Cardiovascular Diseases, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Marco Das
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands.,Department of Diagnostic and Interventional Radiology, Duisburg, Germany
| |
Collapse
|
16
|
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.
Collapse
|
17
|
Verification of the Dose Reduction Effect via Diluted Injection in Dual-Energy Computed Tomography Using a Human Blood Flow Phantom. Radiol Res Pract 2019; 2019:3512126. [PMID: 31057968 PMCID: PMC6463575 DOI: 10.1155/2019/3512126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 03/06/2019] [Indexed: 11/17/2022] Open
Abstract
Purpose. We sought to examine the possibility of reducing the contrast medium dosage in dual-energy imaging using a saline-mixed injection with a virtual monochromatic energy method of dual-source computed tomography (CT). Methods. An X-ray CT (SOMATOM Definition Flash: Siemens, Nurnberg, Germany) was employed. The mixing ratio of contrast medium and saline was gradually changed by 10%, followed by a mixed injection into a dynamic blood flow phantom (Nemoto Kyorindo, Japan) which is a hemodynamic simulation phantom to obtain time-enhancement curves (TECs). Exactly 64 TECs were prepared for each mixing ratio by changing the energy from 40 to 75 keV for monoenergetic imaging. The relationship between the image standard deviation (SD) and the energy of the virtual monochromatic image was determined. Combinations of the mixing ratio and energy (keV), which can maintain high CT numbers and low image SDs for 3D imaging, were tested, and the reduction rate of the contrast medium was calculated. Results. The TECs for the mixed injection method changed linearly with the dilution rates. The mixing ratios were strongly correlated with the maximum CT number of the TEC (R2 = 0.98). Contrast CT numbers and image SDs increased by approximately 20% and 25%, respectively, as the energy decreased by 5 keV. The optimal conditions for reducing the contrast medium dose were a mixing ratio of 6:4 and 55 keV of energy. Conclusion. The virtual monochromatic energy method reduced the contrast medium dosage by up to 40% for three-dimensional CT-angio (3DCTA) tests.
Collapse
|
18
|
Ohno Y, Koyama H, Seki S, Kishida Y, Yoshikawa T. Radiation dose reduction techniques for chest CT: Principles and clinical results. Eur J Radiol 2018; 111:93-103. [PMID: 30691672 DOI: 10.1016/j.ejrad.2018.12.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 12/06/2018] [Accepted: 12/16/2018] [Indexed: 11/19/2022]
Abstract
Computer tomography plays a major role in the evaluation of thoracic diseases, especially since the advent of the multidetector-row CT (MDCT) technology. However, the increase use of this technique has raised some concerns about the resulting radiation dose. In this review, we will present the various methods allowing limiting the radiation dose exposure resulting from chest CT acquisitions, including the options of image filtering and iterative reconstruction (IR) algorithms. The clinical applications of reduced dose protocols will be reviewed, especially for lung nodule detection and diagnosis of pulmonary thromboembolism. The performance of reduced dose protocols for infiltrative lung disease assessment will also be discussed. Lastly, the influence of using IR algorithms on computer-aided detection and volumetry of lung nodules, as well as on quantitative and functional assessment of chest diseases will be presented and discussed.
Collapse
Affiliation(s)
- Yoshiharu Ohno
- Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Japan; Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Japan.
| | | | - Shinichiro Seki
- Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Japan; Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Japan
| | - Yuji Kishida
- Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Japan
| | - Takeshi Yoshikawa
- Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Japan; Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Japan
| |
Collapse
|
19
|
Mann C, Ziegeler K, Mews J, Plaschke M, Issever AS. Bone mineral density assessment using iterative reconstruction compared with quantitative computed tomography as the standard of reference. Sci Rep 2018; 8:15095. [PMID: 30305658 PMCID: PMC6179993 DOI: 10.1038/s41598-018-33444-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 09/28/2018] [Indexed: 12/13/2022] Open
Abstract
This study examines the influence of iterative reconstruction on bone mineral density (BMD) measurement by comparison with standard quantitative computed tomography (QCT; reference) and two other protocols based on filtered back projection. Ten human cadaver specimens of the lumbar spine with a hydroxyapatite calibration phantom underneath, were scanned with 4 protocols: 1. standard QCT, 2. volume scan with FBP, 3. helical scan with FBP, and 4. helical scan with IR (Adaptive Iterative Dose Reduction 3D (AIDR3D)). Radiation doses were recorded as CT dose index (CTDIvol) and BMD, signal-to-noise and contrast-to-noise ratio were calculated. Mean hydroxyapatite concentration (HOA) did not differ significantly between protocols, ranging from 98.58 ± 31.09 mg cm3 (protocol 4) to 100.47 ± 30.82 mg cm3 (protocol 2). Paired sample correlations of HOA values for protocol 4 and protocols 1, 2 and 3 were nearly perfect with coefficients of 0.980, 0.979 and 0.982, respectively (p < 0.004). CTDIvol were 7.50, 5.00, 6.82 (±2.03) and 1.72 (±0.50) mGy for protocols 1, 2, 3 and 4 respectively. Objective image quality was highest for protocol 4. The use of IR for BMD assessment significantly lowers radiation exposure compared to standard QCT and protocols with FBP while not degrading BMD measurement.
Collapse
Affiliation(s)
- Constanze Mann
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
| | - Katharina Ziegeler
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jürgen Mews
- Canon Medical Systems Europe BV, Zoetermeer, Netherlands
| | - Martina Plaschke
- Department of Anatomy, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Ahi Sema Issever
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
20
|
Sasaki T, Fujimoto Y, Ishitoya S, Nabaa B, Watanabe N, Yamaki T, Takahashi K. Improved detectability of thromboses of the lower limb using low kilovoltage computed tomography. Medicine (Baltimore) 2018; 97:e9775. [PMID: 29419670 PMCID: PMC5944700 DOI: 10.1097/md.0000000000009775] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
To determine the utility of low kilovoltage computed tomographic venography (CTV) for the detection of deep venous thrombus in the lower limbs.Twenty-one thrombi in 19 enrolled patients were investigated in this retrospective study. Patients were initially scanned using CTV at 100 kVp, at the femur level, followed by an immediate switch to 80 kVp. We assessed the CT values of thrombi and veins and performed subjective evaluation for detecting thrombi using a 5-point scoring system: 1, unable to evaluate due to noise or artifacts; 2, equivocal venous thrombus; 3, possible venous thrombus; 4, probable venous thrombus; and 5, definite venous thrombus.Venous density on 100-kVp images (mean ± SD [standard deviation]: 122 ± 23 HU, 95% confidence interval [CI]: 111-133 Hounsfield unit [HU]) was significantly lower than that on 80-kVp images (136 ± 24 HU, 95% CI: 125-147 HU, P < .001). There was no significant difference in thrombi between 100-kVp images (55 ± 14 HU, 95% CI: 49-61 HU) and 80-kVp images (57 ± 16, 95% CI: 50-64 HU, P = .168). The thrombus to vein ratio on 100-kVp images (0.47 ± 0.20, 95% CI: 0.39-0.56) was significantly higher than that on 80-kVp images (0.44 ± 0.16, 95% CI: 0.37-0.51, P = .048). The mean 5-point score was significantly higher on the 80-kVp images (4.76) than on the 100-kVp images (4.45, P = .016).Lower kilovoltage CTV significantly improved thrombotic to venous contrasts in the lower limbs.
Collapse
|
21
|
Prospective ECG-triggering cardiac CT for infants with complex congenital heart disease using low-dose contrast medium, low tube voltage, and adaptive statistical iterative reconstruction. Clin Radiol 2017; 72:502-507. [PMID: 28267987 DOI: 10.1016/j.crad.2017.01.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 01/04/2017] [Accepted: 01/30/2017] [Indexed: 11/21/2022]
Abstract
AIM To demonstrate the clinical value of prospective electrocardiography (ECG)-triggered cardiac computed tomography (CT) with low concentration contrast medium, low tube voltage, and adaptive statistic iterative reconstruction (ASIR) to reduce both radiation and contrast dose in examining infants with complex congenital heart disease (CHD). MATERIALS AND METHODS Forty-four consecutive infants (19 male, 25 female, age: 8.06±4.33 months, weight: 7.31±1.36 kg) with complex CHD underwent prospective ECG-triggered low-dose cardiac CT using 80 kVp and 120 mA. The contrast agent was iodixanol (270 mg iodine/ml, Visipaque, GE Healthcare, Co. Cork, Ireland). Cardiac CT images were reconstructed with 70% ASIR. The quantitative CT image quality was assessed by image noise in adipose tissue and contrast-to-noise ratio (CNR) in the aorta. The qualitative image analysis was performed on a five-point grading scale by two independent reviewers and interobserver variability was calculated. The results of 32 CT examinations were also compared with the available surgical results for diagnostic accuracy evaluation. RESULTS The effective dose was 0.55±0.10 mSv for the patient population. The iodine load was 3.95±0.73 g iodine. Image noise in adipose tissue was 16.24±1.42 HU and CNR in aorta was 21.90±7.10. All images were acceptable for diagnosis with an average score of 4.52±0.38 and good agreement between reviewers (kappa=0.75). Compared to the surgery results in 32 cases, CT was 97% and 88% accurate diagnosing extracardiac and intracardiac defects, respectively. CONCLUSION Prospective ECG-triggered cardiac CT using 80 kVp, low-concentration iodinated contrast agent (270 mg iodine/ml) and 70% ASIR reconstruction provides excellent image quality and accurate diagnosis for complex congenital heart disease in infants with reduced contrast medium dose and low radiation dose.
Collapse
|
22
|
CT image quality in sinogram affirmed iterative reconstruction phantom study - is there a point of diminishing returns? Pediatr Radiol 2017; 47:333-341. [PMID: 27891546 DOI: 10.1007/s00247-016-3745-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 08/25/2016] [Accepted: 10/31/2016] [Indexed: 01/01/2023]
Abstract
BACKGROUND In our pediatric practice, we have observed qualitatively limited improvement in the image quality of images generated with sinogram affirmed iterative reconstruction (SAFIRE) compared to series generated with filtered back projection (FBP), particularly in cases near or below a CT dose index volume (CTDIvol) of 1-mGy. OBJECTIVE To determine whether the image quality advantage of SAFIRE remains constant across clinically used CT dose levels in an American College of Radiology (ACR) CT accreditation phantom including the lower dose range used in pediatric imaging. MATERIALS AND METHODS An exemption from institutional review board approval was obtained for this phantom-based study. An ACR quality phantom was scanned in incremental kV steps and effective tube current intervals. Acquisitions were reconstructed with FBP and SAFIRE strengths of 1, 3 and 5. Image quality measures were calculated including signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), low-contrast resolution and high-contrast resolution. Peak SNR was also calculated. Descriptive and nonparametric statistics were used to compare these image quality metrics while normalizing to CT dose index (CTDI). RESULTS The percent improvement in SNR and peak SNR of SAFIRE reconstructions compared to FBP decreased from about 70% for image sets acquired above a 1.42 mGy CTDI to 25% at a 0.25 mGy CTDI. CNR improvement with SAFIRE did not vary with dose. No significant difference was seen in the low-contrast resolution or high-contrast resolution of SAFIRE images compared to FBP. CONCLUSION SNR did not improve equally after applying SAFIRE across a spectrum clinically used CTDIs. Below a threshold CTDI, the incremental improvement of SAFIRE compared to FBP decreased.
Collapse
|
23
|
Miyata K, Nagatani Y, Ikeda M, Takahashi M, Nitta N, Matsuo S, Ohta S, Otani H, Nitta-Seko A, Murakami Y, Tsuchiya K, Inoue A, Misaki S, Erdenee K, Kida T, Murata K. A phantom study for ground-glass nodule detectability using chest digital tomosynthesis with iterative reconstruction algorithm by ten observers: association with radiation dose and nodular characteristics. Br J Radiol 2017; 90:20160555. [PMID: 28102693 DOI: 10.1259/bjr.20160555] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE To compare detectability of simulated ground-glass nodules (GGNs) on chest digital tomosynthesis (CDT) among 12 images obtained at 6 radiation doses using 2 reconstruction algorithms and to analyze its association with nodular size and density. METHODS 74 simulated GGNs [5, 8 and 10 mm in diameter/-630 and -800 Hounsfield units (HU) in density] were placed in a chest phantom in 14 nodular distribution patterns. 12 sets of coronal images were obtained using CDT at 6 radiation doses: 120 kV-10 mA/20 mA/80 mA/160 mA, 100 kV-80 mA and 80 kV-320 mA with and without iterative reconstruction (IR). 10 radiologists recorded GGN presence and locations by continuously distributed rating. GGN detectability was compared by receiver operating characteristic analysis among 12 images and detection sensitivities (DS) were compared among 12 images in subgroups classified by nodular diameters and densities. RESULTS GGN detectability at 120 kV-160 mA with IR was similar to that at 120 kV-80 mA with IR (0.614 mSv), as area under receiver operating characteristic curve was 0.798 ± 0.024 and 0.788 ± 0.025, respectively, and higher than six images acquired at 120 kV (p < 0.05). For nodules of -630 HU/8 mm, DS at 120 kV-10 mA without IR was 73.5 ± 6.0% and was similar to that by the other 11 data acquisition methods (p = 0.157). For nodules of -800 HU/10 mm, DS both at 120 kV-80 mA and 120 kV-160 mA without IR was improved by IR (56.3 ± 11.9%) (p < 0.05). CONCLUSION CDT demonstrated sufficient detectability for larger more-attenuated GGNs (>8 mm) even in the lowest radiation dose (0.17 mSv) and improved detectability for less-attenuated GGNs with the diameter of 10 mm at submillisievert with IR. Advances in knowledge: IR improved detectability for larger less-attenuated simulated GGNs on CDT.
Collapse
Affiliation(s)
- Katsunori Miyata
- 1 Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Yukihiro Nagatani
- 1 Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Mitsuru Ikeda
- 2 Department of Radiological Technology, Nagoya University School of Health Science, Higashi-ku, Nagoya, Japan
| | - Masashi Takahashi
- 1 Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan.,3 Department of Radiology, Yujin-Yamazaki Hospital, Hikone, Shiga, Japan
| | - Norihisa Nitta
- 1 Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Satoru Matsuo
- 4 Department of Radiological Technology, Kyoto College of Medical Science, Nantan, Kyoto, Japan
| | - Shinichi Ohta
- 1 Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Hideji Otani
- 1 Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Ayumi Nitta-Seko
- 1 Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Yoko Murakami
- 1 Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Keiko Tsuchiya
- 1 Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Akitoshi Inoue
- 1 Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Sayaka Misaki
- 5 Department of Radiology, Ijinkai-Takeda General Hospital, Fushimi-ku, Kyoto, Japan
| | - Khishigdorj Erdenee
- 6 Department of Radiology, EMC-KENKO Hospital, Health Science University of Mongolia, Orkhon, Mongolia
| | - Tetsuo Kida
- 1 Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Kiyoshi Murata
- 1 Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| |
Collapse
|
24
|
Zhao YX, Zuo ZW, Suo HN, Wang JN, Chang J. CT Pulmonary Angiography Using Automatic Tube Current Modulation Combination with Different Noise Index with Iterative Reconstruction Algorithm in Different Body Mass Index: Image Quality and Radiation Dose. Acad Radiol 2016; 23:1513-1520. [PMID: 27717760 DOI: 10.1016/j.acra.2016.07.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 06/20/2016] [Accepted: 07/01/2016] [Indexed: 10/20/2022]
Abstract
RATIONALE AND OBJECTIVES This study aimed to determine the appropriate body mass index (BMI)-dependent noise index (NI) setting in computed tomography pulmonary angiography (CTPA) with automatic tube current modulation with adaptive statistical iterative reconstruction (ASiR). MATERIALS AND METHODS A total of 480 patients who had a CTPA were divided into group A (18.5 kg/m2 ≤ BMI < 25 kg/m2), group B (25 kg/m2 ≤ BMI < 30 kg/m2), and group C (BMI ≥ 30 kg/m2), according to their BMI values; each group had 160 patients. The three groups were further randomly divided into four subgroups: A1, A2, A3, A4; B1, B2, B3, B4; and C1, C2, C3, C4, with corresponding NI values of 26, 36, 40, and 46, respectively. All images were restructured with the ASiR algorithm, and the images with the lowest NI (26 Hounsfield units) in each group were used as reference standard. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) for the pulmonary artery of each group were calculated. Subjective image quality was evaluated using a five-score method by two independent radiologists. The CT dose index of volume and dose-length product were recorded and were converted to effective dose (ED). SNR and CNR in the group A, B, and C subgroups were compared to repeated measures analysis of variance, and the subjective score, Volumetric CT dose index of volume, dose-length product, and ED were compared to one-way analysis of variance. RESULTS For groups A and B, the SNR, CNR, and subjective scores of the images in their subgroups showed no statistical differences (P >.05). The ED in subgroups A4 and B4 was significantly lower than that in subgroups A1 (by 33.24%) and B1 (by 34.47%) (P <.01). For group C, there was no significant difference in the SNR, CNR, and the subjective image scores between subgroups C3 and C1 (P >.05). The ED in subgroup C3 was significantly lower than the ED in subgroup C1 (by 47.75%) (P <.01) CONCLUSIONS: Patient BMI-dependent NI settings that are higher than the recommended value may be used in CTPA with automatic tube current modulation and ASiR to effectively reduce radiation dose while maintaining diagnostic image quality.
Collapse
|
25
|
State-of-the-Art Pulmonary CT Angiography for Acute Pulmonary Embolism. AJR Am J Roentgenol 2016; 208:495-504. [PMID: 27897042 DOI: 10.2214/ajr.16.17202] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Pulmonary CT angiography (CTA) is the imaging modality of choice in suspected acute pulmonary embolism (PE). Current pulmonary CTA techniques involve ever lower doses of contrast medium and radiation along with advanced postprocessing applications to enhance image quality, diagnostic accuracy, and provide added value in patient management. The objective of this article is to summarize these current developments and discuss the appropriate use of state-of-the-art pulmonary CTA. CONCLUSION Pulmonary CTA is well established as a fast and reliable means of excluding or diagnosing PE. Continued developments in CT system hardware and postprocessing techniques will allow incremental reductions in radiation and contrast material requirements while improving image quality. Advances in risk stratification and prognostication from pulmonary CTA examinations should further refine its clinical value while minimizing the potential harm from overutilization and overdiagnosis.
Collapse
|
26
|
Song I, Yi JG, Park JH, Ko SM. Indirect CT Venography at 80 kVp with Sinogram-Affirmed Iterative Reconstruction Compared to 120 kVp with Filtered Back Projection: Assessment of Image Quality and Radiation Dose. PLoS One 2016; 11:e0163416. [PMID: 27662618 PMCID: PMC5035093 DOI: 10.1371/journal.pone.0163416] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 09/08/2016] [Indexed: 11/30/2022] Open
Abstract
Objective To evaluate the image quality and radiation dose of indirect computed tomographic venography (CTV) using 80 kVp with sinogram-affirmed iterative reconstruction (SAFIRE) and 120 kVp with filtered back projection (FBP). Materials and Methods This retrospective study was approved by our institution and informed consent was waived. Sixty-one consecutive patients (M: F = 27: 34, mean age 60 ± 16, mean BMI 23.6 ± 3.6 kg/m2) underwent pelvic and lower extremity CTVs [group A (n = 31, 120 kVp, reconstructed with FBP) vs. group B (n = 30, 80 kVp, reconstructed with SAFIRE)]. The vascular enhancement, image noise, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) were compared. Subjective image analysis for image quality and noise was performed by two radiologists. Radiation dose was compared between the two groups. Results Compared with group A, higher mean vascular enhancement was observed in the group B (group A vs. B, 118.8 ± 15.7 HU vs. 178.6 ± 39.6 HU, p < 0.001), as well as image noise (12.0 ± 3.8 HU vs. 17.9 ± 6.1 HU, p < 0.001) and CNR (5.1 ± 1.9 vs. 7.6 ± 3.0, p < 0.001). The SNRs were not significantly different in both groups (11.2 ± 4.8 vs. 10.8 ± 3.7, p = 0.617). There was no significant difference in subjective image quality between the two groups (all p > 0.05). The subjective image noise was higher in the group B (p = 0.036 in reader 1, p = 0.005 in reader 2). The inter-observer reliability for assessing subjective image quality was good (ICC 0.746~0.784, p < 0.001). The mean CT dose index volume (CTDIvol) and mean dose length product (DLP) were significantly lower in group B than group A [CTDIvol, 6.4 ± 1.3 vs. 2.2 ± 2.2 mGy (p < 0.001); DLP, 499.1 ± 116.0 vs. 133.1 ± 45.7 mGy × cm (p < 0.001)]. Conclusions CTV using 80 kVp combined with SAFIRE provides lower radiation dose and improved CNR compared to CTV using 120 kVp with FBP.
Collapse
Affiliation(s)
- Inyoung Song
- Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, 143–729, Korea
| | - Jeong Geun Yi
- Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, 143–729, Korea
- * E-mail:
| | - Jeong Hee Park
- Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, 143–729, Korea
| | - Sung Min Ko
- Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, 143–729, Korea
| |
Collapse
|
27
|
Laqmani A, Kurfürst M, Butscheidt S, Sehner S, Schmidt-Holtz J, Behzadi C, Nagel HD, Adam G, Regier M. CT Pulmonary Angiography at Reduced Radiation Exposure and Contrast Material Volume Using Iterative Model Reconstruction and iDose4 Technique in Comparison to FBP. PLoS One 2016; 11:e0162429. [PMID: 27611448 PMCID: PMC5017776 DOI: 10.1371/journal.pone.0162429] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 07/28/2016] [Indexed: 12/01/2022] Open
Abstract
Purpose To assess image quality of CT pulmonary angiography (CTPA) at reduced radiation exposure (RD-CTPA) and contrast medium (CM) volume using two different iterative reconstruction (IR) algorithms (iDose4 and iterative model reconstruction (IMR)) in comparison to filtered back projection (FBP). Materials and Methods 52 patients (body weight < 100 kg, mean BMI: 23.9) with suspected pulmonary embolism (PE) underwent RD-CTPA (tube voltage: 80 kV; mean CTDIvol: 1.9 mGy) using 40 ml CM. Data were reconstructed using FBP and two different IR algorithms (iDose4 and IMR). Subjective and objective image quality and conspicuity of PE were assessed in central, segmental, and subsegmental arteries. Results Noise reduction of 55% was achieved with iDose4 and of 85% with IMR compared to FBP. Contrast-to-noise ratio significantly increased with iDose4 and IMR compared to FBP (p<0.05). Subjective image quality was rated significantly higher at IMR reconstructions in comparison to iDose4 and FBP. Conspicuity of central and segmental PE significantly improved with the use of IMR. In subsegmental arteries, iDose4 was superior to IMR. Conclusions CTPA at reduced radiation exposure and contrast medium volume is feasible with the use of IMR, which provides improved image quality and conspicuity of pulmonary embolism in central and segmental arteries.
Collapse
Affiliation(s)
- Azien Laqmani
- Department for Interventional and Diagnostic Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- * E-mail:
| | - Maximillian Kurfürst
- Department for Interventional and Diagnostic Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sebastian Butscheidt
- Department for Interventional and Diagnostic Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Susanne Sehner
- Department of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jakob Schmidt-Holtz
- Department for Interventional and Diagnostic Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Cyrus Behzadi
- Department for Interventional and Diagnostic Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Gerhard Adam
- Department for Interventional and Diagnostic Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Marc Regier
- Department for Interventional and Diagnostic Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| |
Collapse
|
28
|
Wang X, Zhong Y, Hu L, Xue L, Shi M, Qiu H, Li J. A prospective evaluation of the contrast, radiation dose and image quality of contrast-enhanced CT scans of paediatric abdomens using a low-concentration iodinated contrast agent and low tube voltage combined with 70% ASIR algorithm. Int J Clin Pract 2016; 70 Suppl 9B:B16-21. [PMID: 27577509 DOI: 10.1111/ijcp.12853] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 06/15/2016] [Indexed: 10/21/2022] Open
Abstract
PURPOSE To quantitatively and subjectively assess the image quality of and radiation dose for an abdominal enhanced computed tomography (CT) scan with a low tube voltage and a low concentration of iodinated contrast agent in children. METHODS Forty-eight patients were randomised to one of the two following protocols: Group A (n=24, mean age 46.96±44.65 months, mean weight 15.71±9.11 kg, BMI 16.48±2.40 kg/m(2) ) and Group B (n=24, mean age 41.33±44.59 months, mean weight 18.15±17.67 kg, BMI 17.50±3.73 kg/m(2) ). Group A: 80 kVp tube voltage, 270 mg iodine (I)/mL contrast agent (Visipaque, GE Healthcare) and images were reconstructed using 70% adaptive statistical iterative reconstruction (ASIR). Group B: 100 kVp tube voltage, 370 mg I/mL contrast agent (Iopamiro, Bracco) and images were reconstructed using 50% ASIR. The volume of the contrast agent was 1.30 mL/kg in both Groups A and B. The degree of enhancement and noise in the abdominal aorta (AO) in the arterial phase (AP) and the portal vein (PV) in the portal venous phase (PVP) was measured; while the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) for the AO and PV were calculated. A 5-point scale was used to subjectively evaluate the image quality and image noise by two radiologists with more than 10 years of experience. Dose-length product (DLP) (mGy-cm) and CTDIvol (mGy) were calculated. Objective measurements and subjective quality scores for the two groups were compared using paired t-tests and Mann-Whitney U tests, respectively. RESULTS There was no significant difference in age, weight or body mass index (BMI) between the two groups (all P>.5). The iodine load in Group A (5517.3±3197.2 mg I) was 37% lower than that in Group B (8772.1±8474.6 mg I), although there was no significant difference between them (P=.111). The DLP and the CT dose index (CTDIvol ) for Group A were also lower than for Group B, but were not statistically significantly different (DLP, 104 mGy-cm±45.81 vs 224.5 mGy-cm±45.83; CTDIvol, 1.44 mGy±0.50 vs 2.08 mGy±1.87, all P>.05). The mean arterial and portal venous enhancement (255.33 HU±83.42, 146.41 HU±23.45, respectively), noise (AP 14.96 HU±2.09, PVP 16.30 HU±3.21), CNRs (AO 14.54±7.12, PV 5.07±1.73) and SNRs (AO 20.76±6.76, PV 12.43±3.24) for Group A were similar to Group B (enhancement: 226.55 HU±77.71, 138.69 HU±33.22; noise: 14.92 HU±3.12, 15.36 HU±3.48; CNRs: 12.96±7.14, 5.16±2.28; SNRs: 19.13±7.30, 12.69±4.22; all P>.05). The mean scores of the quality of the AP and PVP images in Group B were 4.31±0.53 and 4.35±0.52, respectively, while the scores obtained in Group A were 4.29±0.51 and 4.25±0.51; there were no statistically significant differences between the two groups. CONCLUSION The scanning protocol using a low tube voltage (80 kVp) together with 70% ASIR and a low-concentration iodinated contrast agent (270 mg I/mL) enables a 37% reduction in iodine load and a 30% reduction in radiation dose while maintaining compatible image quality.
Collapse
Affiliation(s)
- Xiaoxia Wang
- Diagnostic Imaging Center, Shanghai Children's Medical Center affiliated with Shanghai Jiao Tong University Medical School, Shanghai, China
| | - Yumin Zhong
- Diagnostic Imaging Center, Shanghai Children's Medical Center affiliated with Shanghai Jiao Tong University Medical School, Shanghai, China
| | - Liwei Hu
- Diagnostic Imaging Center, Shanghai Children's Medical Center affiliated with Shanghai Jiao Tong University Medical School, Shanghai, China
| | - Lianyan Xue
- Diagnostic Imaging Center, Shanghai Children's Medical Center affiliated with Shanghai Jiao Tong University Medical School, Shanghai, China
| | - Meihua Shi
- Diagnostic Imaging Center, Shanghai Children's Medical Center affiliated with Shanghai Jiao Tong University Medical School, Shanghai, China
| | - Haisheng Qiu
- Diagnostic Imaging Center, Shanghai Children's Medical Center affiliated with Shanghai Jiao Tong University Medical School, Shanghai, China
| | - Jianying Li
- CT Research Center, GE Healthcare China, Shanghai, China
| |
Collapse
|
29
|
Kok M, Mihl C, Hendriks BMF, Altintas S, Kietselaer BLJH, Wildberger JE, Das M. Optimizing contrast media application in coronary CT angiography at lower tube voltage: Evaluation in a circulation phantom and sixty patients. Eur J Radiol 2016; 85:1068-74. [PMID: 27161054 DOI: 10.1016/j.ejrad.2016.03.022] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 02/09/2016] [Accepted: 03/20/2016] [Indexed: 01/11/2023]
Affiliation(s)
- Madeleine Kok
- Department of Radiology, Maastricht University Medical Center, The Netherlands; CARIM, School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands.
| | - Casper Mihl
- Department of Radiology, Maastricht University Medical Center, The Netherlands; CARIM, School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands.
| | - Babs M F Hendriks
- Department of Radiology, Maastricht University Medical Center, The Netherlands.
| | - Sibel Altintas
- CARIM, School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Cardiology, Maastricht University Medical Center, The Netherlands.
| | - Bas L J H Kietselaer
- Department of Radiology, Maastricht University Medical Center, The Netherlands; CARIM, School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Cardiology, Maastricht University Medical Center, The Netherlands.
| | - Joachim E Wildberger
- Department of Radiology, Maastricht University Medical Center, The Netherlands; CARIM, School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands.
| | - Marco Das
- Department of Radiology, Maastricht University Medical Center, The Netherlands; CARIM, School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, The Netherlands.
| |
Collapse
|
30
|
Bahn YE, Kim SH, Kim MJ, Kim CS, Kim YH, Cho SH. Detection of Urothelial Carcinoma: Comparison of Reduced-Dose Iterative Reconstruction with Standard-Dose Filtered Back Projection. Radiology 2016; 279:471-80. [DOI: 10.1148/radiol.2015150257] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
31
|
Emphysema Quantification Using Ultralow-Dose CT With Iterative Reconstruction and Filtered Back Projection. AJR Am J Roentgenol 2016; 206:1184-92. [PMID: 27058307 DOI: 10.2214/ajr.15.15684] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE The purpose of this study was to evaluate agreement between standard-dose CT (SDCT) and ultralow-dose CT (ULDCT) findings with respect to emphysema quantification. ULDCT images were reconstructed with and without iterative reconstruction (IR). Adaptive iterative dose reduction with 3D processing was used for IR. MATERIALS AND METHODS Fifty patients who underwent SDCT and ULDCT were included. The tube current for SDCT was 250 mA, and that for ULDCT was 10 mA. SDCT, ULDCT without IR, and ULDCT with IR were used for emphysema quantification. The low-attenuation volume percentage (LAV%) in the lungs at four thresholds (-970, -950, -930, and -910 HU), mean lung attenuation, and total lung volume were computed. Concordance correlation coefficients (CCC) were used to assess the agreement of emphysema quantification between SDCT and ULDCT. RESULTS The LAV% CCC values were 0.310-0.789 between SDCT and ULDCT without IR and 0.934-0.966 between SDCT and ULDCT with IR. The agreement of LAV% improved when IR was used for ULDCT. The mean lung attenuation CCC value between SDCT and ULDCT without IR was substantial (0.957), whereas that between SDCT and ULDCT with IR was poor (0.890). The total lung volume CCC values were substantial (0.982 with IR, 0.983 without IR). CONCLUSION ULDCT with and without IR can substitute for SDCT in emphysema quantification.
Collapse
|
32
|
Kok M, de Haan MW, Mihl C, Eijsvoogel NG, Hendriks BM, Sailer AM, Derks K, Schnerr RS, Schurink GWH, Wildberger JE, Das M. Individualized CT Angiography Protocols for the Evaluation of the Aorta: A Feasibility Study. J Vasc Interv Radiol 2016; 27:531-8. [DOI: 10.1016/j.jvir.2016.01.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 01/02/2016] [Accepted: 01/02/2016] [Indexed: 01/16/2023] Open
|
33
|
Synergistic Radiation Dose Reduction by Combining Automatic Tube Voltage Selection and Iterative Reconstruction. J Thorac Imaging 2016; 31:111-8. [DOI: 10.1097/rti.0000000000000196] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
34
|
Lim HK, Ha HI, Hwang HJ, Lee K. Feasibility of high-pitch dual-source low-dose chest CT: Reduction of radiation and cardiac artifacts. Diagn Interv Imaging 2016; 97:443-9. [PMID: 26896374 DOI: 10.1016/j.diii.2016.01.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 01/07/2016] [Accepted: 01/07/2016] [Indexed: 11/17/2022]
Abstract
PURPOSE To compare the radiation dose and image quality, focused mainly on cardiac pulsation artifact, between high-pitch low-dose chest computed tomography (HP-LDCT) and standard low-dose chest CT (LDCT). PATIENTS AND METHODS One hundred patients underwent HP-LDCT (50 patients) or LDCT (50 patients). Scan parameters were the same except for the pitch and gantry rotation time: 3.0 vs. 1.2 and 0.28s vs. 0.5s, respectively. Objective image noise at five regions and subjective image quality, such as noise, artifacts, cardiac pulsation artifacts, and overall diagnostic acceptability, were evaluated using a five-point scale. The significance level for all tests was set at P<0.05. RESULTS The dose-length products (DLPs) with HP-LDCT and LDCT were 90.2±4.3mGycm and 103.1±6.4mGycm, respectively (P<0.01). DLP of HP-LDCT showed a 13% reduction versus LDCT. Objective image noise was not significantly different. Cardiac pulsation artifacts showed a significant reduction on HP-LDCT (P<0.01). Other subjective image quality parameters of HP-LDCT were similar to those of LDCT. The overall diagnostic acceptability of HP-LDCT was better than that of LDCT (P<0.01). CONCLUSIONS HP-LDCT showed a 13% mean radiation dose reduction with no deterioration in image quality due to cardiac pulsation artifacts.
Collapse
Affiliation(s)
- H K Lim
- Department of Radiology, Soonchunhyang University Seoul Hospital, 59 Daesagwan-ro, Yongsan-gu, Seoul, 140-743, Republic of Korea.
| | - H I Ha
- Department of Radiology, Hallym University Medical Center, Hallym University Sacred Heart Hospital, 896 Pyeongchon-dong, Dongan-gu, Anyang-si, Gyeonggi-do, 431-070, Republic of Korea.
| | - H J Hwang
- Department of Radiology, Hallym University Medical Center, Hallym University Sacred Heart Hospital, 896 Pyeongchon-dong, Dongan-gu, Anyang-si, Gyeonggi-do, 431-070, Republic of Korea.
| | - K Lee
- Department of Radiology, Hallym University Medical Center, Hallym University Sacred Heart Hospital, 896 Pyeongchon-dong, Dongan-gu, Anyang-si, Gyeonggi-do, 431-070, Republic of Korea.
| |
Collapse
|
35
|
Sabel BO, Buric K, Karara N, Thierfelder KM, Dinkel J, Sommer WH, Meinel FG. High-Pitch CT Pulmonary Angiography in Third Generation Dual-Source CT: Image Quality in an Unselected Patient Population. PLoS One 2016; 11:e0146949. [PMID: 26872262 PMCID: PMC4752234 DOI: 10.1371/journal.pone.0146949] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 12/22/2015] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES To investigate the feasibility of high-pitch CT pulmonary angiography (CTPA) in 3rd generation dual-source CT (DSCT) in unselected patients. METHODS Forty-seven patients with suspected pulmonary embolism underwent high-pitch CTPA on a 3rd generation dual-source CT scanner. CT dose index (CTDIvol) and dose length product (DLP) were obtained. Objective image quality was analyzed by calculating signal-to-noise-ratio (SNR) and contrast-to-noise ratio (CNR). Subjective image quality on the central, lobar, segmental and subsegmental level was rated by two experienced radiologists. RESULTS Median CTDI was 8.1 mGy and median DLP was 274 mGy*cm. Median SNR was 32.9 in the central and 31.9 in the segmental pulmonary arteries. CNR was 29.2 in the central and 28.2 in the segmental pulmonary arteries. Median image quality was "excellent" in central and lobar arteries and "good" in subsegmental arteries according to both readers. Segmental arteries varied between "excellent" and "good". Image quality was non-diagnostic in one case (2%), beginning in the lobar arteries. Thirteen patients (28%) showed minor motion artifacts. CONCLUSIONS In third-generation dual-source CT, high-pitch CTPA is feasible for unselected patients. It yields excellent image quality with minimal motion artifacts. However, compared to standard-pitch cohorts, no distinct decrease in radiation dose was observed.
Collapse
Affiliation(s)
- Bastian O. Sabel
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Kristijan Buric
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Nora Karara
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Kolja M. Thierfelder
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Julien Dinkel
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Wieland H. Sommer
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Felix G. Meinel
- Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany
| |
Collapse
|
36
|
Yamamura S, Oda S, Imuta M, Utsunomiya D, Yoshida M, Namimoto T, Yuki H, Kidoh M, Funama Y, Baba H, Yamashita Y. Reducing the Radiation Dose for CT Colonography: Effect of Low Tube Voltage and Iterative Reconstruction. Acad Radiol 2016; 23:155-62. [PMID: 25872861 DOI: 10.1016/j.acra.2015.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Revised: 02/27/2015] [Accepted: 03/08/2015] [Indexed: 12/17/2022]
Abstract
RATIONALE AND OBJECTIVES The purpose of this study was to assess the effect of a low-tube-voltage technique and iterative reconstruction (IR) on the radiation dose and image quality of computed tomography colonography (CTC). MATERIALS AND METHODS We studied 30 patients (14 women and 16 men; mean age, 64.5 ± 13.1 years; range, 39-90 years) with colorectal cancer referred for surgical treatment. All underwent CTC with fecal tagging under a standard 120-kVp protocol in the supine position and a 100-kVp protocol in the prone position. The 120-kVp images were reconstructed with filtered back projection (FBP). The 100-kVp images were postprocessed using FBP and a hybrid type of IR (adaptive iterative dose reduction 3D). The effective radiation dose (ED), image noise, and contrast-to-noise ratio (CNR) were compared among the three protocols. The visual image quality was scored on a four-point scale. RESULTS The mean ED was significantly lower under the 100-kVp protocol than the 120-kVp protocol, resulting in a 27% radiation dose decrease (3.5 ± 2.0 vs 2.5 ± 1.5 mSv; P < .01). Image noise decreased by 48%, and the mean attenuation of tagged fluid increased from 452 to 558 HU on images acquired at 100 kVp with IR compared to that in the 120-kVp protocol; these differences were significant. The mean CNR was significantly higher under the 100 kVp with IR than the other two protocols. We found no significant differences in the visual scores for diagnostic utility between the 100 kVp with IR and the 120 kVp with FBP protocol (P = .10). CONCLUSIONS Low-tube-voltage CTC reduced the radiation dose by approximately 27% while maintaining the image quality.
Collapse
|
37
|
Boos J, Aissa J, Lanzman RS, Heusch P, Schimmöller L, Schleich C, Thomas C, Antoch G, Kröpil P. CT angiography of the aorta using 80 kVp in combination with sinogram-affirmed iterative reconstruction and automated tube current modulation: Effects on image quality and radiation dose. J Med Imaging Radiat Oncol 2016; 60:187-93. [DOI: 10.1111/1754-9485.12425] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Accepted: 11/04/2015] [Indexed: 01/16/2023]
Affiliation(s)
- Johannes Boos
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Joel Aissa
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Rotem S Lanzman
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Philipp Heusch
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Lars Schimmöller
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Christoph Schleich
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Christoph Thomas
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Gerald Antoch
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| | - Patric Kröpil
- Department of Diagnostic and Interventional Radiology; Medical Faculty; University Dusseldorf; Dusseldorf Germany
| |
Collapse
|
38
|
Image Quality in Oncologic Chest Computerized Tomography With Iterative Reconstruction. J Comput Assist Tomogr 2016; 40:351-6. [DOI: 10.1097/rct.0000000000000364] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
39
|
|
40
|
Shimonobo T, Funama Y, Utsunomiya D, Nakaura T, Oda S, Kiguchi M, Masuda T, Sakabe D, Yamashita Y, Awai K. Low-tube-voltage selection for non-contrast-enhanced CT: Comparison of the radiation dose in pediatric and adult phantoms. Phys Med 2016; 32:197-201. [DOI: 10.1016/j.ejmp.2015.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 11/30/2015] [Accepted: 12/11/2015] [Indexed: 11/30/2022] Open
|
41
|
Non–Electrocardiogram-Triggered 70-kVp High-Pitch Computed Tomography Angiography of the Whole Aorta With Iterative Reconstruction. J Comput Assist Tomogr 2016; 40:109-17. [DOI: 10.1097/rct.0000000000000329] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
42
|
Aortic CT angiography dose reduction: investigation of optimal noise index and iterative algorithm strength in combination with low kV. Radiol Med 2015; 121:291-300. [DOI: 10.1007/s11547-015-0611-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 11/26/2015] [Indexed: 12/12/2022]
|
43
|
Macchi M, Floridi C, Strocchi S, Fontana F, Mangini M, Piacentino F, Duka E, Donati AV, Fugazzola C. Role of low dose CT angiography in the follow-up after endovascular aneurysm repair of abdominal aorta. Acta Radiol 2015; 56:1471-8. [PMID: 25487715 DOI: 10.1177/0284185114560210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 10/14/2014] [Indexed: 11/15/2022]
Abstract
BACKGROUND Computed tomography angiography (CTA) is the most employed modality in the follow-up after endovascular aneurysm repair (EVAR) of abdominal aorta (AA); repeated standard controls expose patients to a high cumulative radiation dose (RD). PURPOSE To compare image quality and RD between 100 kV and 120 kV protocols in the same group of patients, previously treated with EVAR. MATERIAL AND METHODS Thirty patients, who had performed a previous CTA at 120 kV, underwent a low dose CTA with the same 64-detector machine. Images were evaluated qualitatively and quantitatively. The influence of body mass index (BMI), considering three groups of patients (normal weight, overweight, and obese) was also assessed. RD values (volume CT dose index and effective dose) were calculated. RESULTS The mean qualitative score at 100 kV was worse than that at 120 kV, but the difference was not statistically significant and in all cases the image quality was satisfactory. At 100 kV the vessels mean attenuation value was significantly higher; signal-to-noise ratio significantly lower; contrast-to-noise ratio lower, but the difference was not significant. Regarding BMI, the difference in the qualitative score was significant in the obese group, but not in the other two groups; of the quantitative parameters only the signal-to-noise ratio presented a significant difference in the obese group. The average CTDIvol was reduced by 22% and the mean effective dose by 36% with the 100 kV protocol compared to the 120 kV protocol. Both differences were significant. CONCLUSION The 100 kV protocol allowed a consistent RD reduction, maintaining a satisfactory image quality in all patients.
Collapse
Affiliation(s)
- Monica Macchi
- Department of Radiology. University Hospital. Varese, Italy
| | - Chiara Floridi
- Department of Radiology. University Hospital. Varese, Italy
| | - Sabina Strocchi
- Department of Medical Physics. University Hospital. Varese, Italy
| | | | - Monica Mangini
- Department of Radiology. University Hospital. Varese, Italy
| | | | - Ejona Duka
- Department of Radiology. University Hospital. Varese, Italy
| | - Alberto V Donati
- Interventional Radiology Research Center. University of Insubria, Varese, Italy
| | | |
Collapse
|
44
|
Kok M, Turek J, Mihl C, Reinartz SD, Gohmann RF, Nijssen EC, Kats S, van Ommen VG, Kietselaer BLJH, Wildberger JE, Das M. Low contrast media volume in pre-TAVI CT examinations. Eur Radiol 2015; 26:2426-35. [PMID: 26560728 PMCID: PMC4927596 DOI: 10.1007/s00330-015-4080-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 09/07/2015] [Accepted: 10/22/2015] [Indexed: 01/02/2023]
Abstract
PURPOSE To evaluate image quality using reduced contrast media (CM) volume in pre-TAVI assessment. METHODS Forty-seven consecutive patients referred for pre-TAVI examination were evaluated. Patients were divided into two groups: group 1 BMI < 28 kg/m(2) (n = 29); and group 2 BMI > 28 kg/m(2) (n = 18). Patients received a combined scan protocol: retrospective ECG-gated helical CTA of the aortic root (80kVp) followed by a high-pitch spiral CTA (group 1: 70 kV; group 2: 80 kVp) from aortic arch to femoral arteries. All patients received one bolus of CM (300 mgI/ml): group 1: volume = 40 ml; flow rate = 3 ml/s, group 2: volume = 53 ml; flow rate = 4 ml/s. Attenuation values (HU) and contrast-to-noise ratio (CNR) were measured at the levels of the aortic root (helical) and peripheral arteries (high-pitch). Diagnostic image quality was considered sufficient at attenuation values > 250HU and CNR > 10. RESULTS Diagnostic image quality for TAVI measurements was obtained in 46 patients. Mean attenuation values and CNR (HU ± SD) at the aortic root (helical) were: group 1: 381 ± 65HU and 13 ± 8; group 2: 442 ± 68HU and 10 ± 5. At the peripheral arteries (high-pitch), mean values were: group 1: 430 ± 117HU and 11 ± 6; group 2: 389 ± 102HU and 13 ± 6. CONCLUSION CM volume can be substantially reduced using low kVp protocols, while maintaining sufficient image quality for the evaluation of aortic root and peripheral access sites. KEY POINTS • Image quality could be maintained using low kVp scan protocols. • Low kVp protocols reduce contrast media volume by 34-67 %. • Less contrast media volume lowers the risk of contrast-induced nephropathy.
Collapse
Affiliation(s)
- Madeleine Kok
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands
- CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands
| | - Jakub Turek
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands
| | - Casper Mihl
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands
- CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands
| | - Sebastian D Reinartz
- Department of Diagnostic and Interventional Radiology, University Hospital, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Robin F Gohmann
- Department of Diagnostic and Interventional Radiology, University Hospital, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Estelle C Nijssen
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands
| | - Suzanne Kats
- Department of Cardiothoracic Surgery, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands
| | - Vincent G van Ommen
- Department of Cardiology, Maastricht University Medical Center MUMC+, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands
| | - Bas L J H Kietselaer
- CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands
- Department of Cardiology, Maastricht University Medical Center MUMC+, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands
| | - Joachim E Wildberger
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands
- CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands
| | - Marco Das
- Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands.
- CARIM School for Cardiovascular Diseases, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands.
- Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ, Maastricht, The Netherlands.
| |
Collapse
|
45
|
Successful Dose Reduction Using Reduced Tube Voltage With Hybrid Iterative Reconstruction in Pediatric Abdominal CT. AJR Am J Roentgenol 2015. [PMID: 26204293 DOI: 10.2214/ajr.14.12698] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVE The purpose of this article is to assess radiation dose reduction, image quality, and diagnostic confidence using low tube voltage in combination with hybrid iterative reconstruction in contrast-enhanced pediatric abdominal CT. MATERIALS AND METHODS CT examinations of 133 patients (median age, 10 years) were performed at sequentially reduced doses. The first group (group 1) was scanned using dimension-based protocols at 120 kV for all patient sizes. The optimized group (group 5) was scanned at 80 kV for less than 18 cm in the lateral dimension and 100 kV in the 19-30 cm lateral dimension. CT examinations reconstructed with filtered back projection (FBP) and four levels of hybrid iterative reconstruction were reviewed by four blinded readers for subjective image quality and diagnostic confidence. Objective noise, volume CT dose index (CTDIvol), and size-specific dose estimate (SSDE) were recorded. Data were analyzed using t tests, one and two-way ANOVA, and the intraclass correlation coefficient. RESULTS Compared with group 1, the radiation dose was reduced for group 5 by 63% measured by SSDE (4.69 vs 10.00 mGy; p < 0.001). Subjective image noise was increased for FBP images (p < 0.001) but not was statistically significantly different for all levels of hybrid iterative reconstruction; artifacts were reduced and visibility of small structures was improved (both p < 0.001). Diagnostic confidence was improved for solid organ injury and metastatic disease (both p < 0.001) and was not statistically significantly different for appendicitis (p = 0.306). CONCLUSION Use of hybrid iterative reconstruction with low-tube-voltage protocols enables substantial radiation dose reduction for pediatric abdominal CT with equivalent to improved subjective image quality and diagnostic confidence.
Collapse
|
46
|
Moorin RE, Gibson DAJ, Forsyth RK, Fox R. The Impact of Iterative Reconstruction on Computed Tomography Radiation Dosimetry: Evaluation in a Routine Clinical Setting. PLoS One 2015; 10:e0138329. [PMID: 26381145 PMCID: PMC4575140 DOI: 10.1371/journal.pone.0138329] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 08/28/2015] [Indexed: 01/31/2023] Open
Abstract
Purpose To evaluate the effect of introduction of iterative reconstruction as a mandated software upgrade on radiation dosimetry in routine clinical practice over a range of computed tomography examinations. Methods Random samples of scanning data were extracted from a centralised Picture Archiving Communication System pertaining to 10 commonly performed computed tomography examination types undertaken at two hospitals in Western Australia, before and after the introduction of iterative reconstruction. Changes in the mean dose length product and effective dose were evaluated along with estimations of associated changes to annual cancer incidence. Results We observed statistically significant reductions in the effective radiation dose for head computed tomography (22–27%) consistent with those reported in the literature. In contrast the reductions observed for non-contrast chest (37–47%); chest pulmonary embolism study (28%), chest/abdominal/pelvic study (16%) and thoracic spine (39%) computed tomography. Statistically significant reductions in radiation dose were not identified in angiographic computed tomography. Dose reductions translated to substantial lowering of the lifetime attributable risk, especially for younger females, and estimated numbers of incident cancers. Conclusion Reduction of CT dose is a priority Iterative reconstruction algorithms have the potential to significantly assist with dose reduction across a range of protocols. However, this reduction in dose is achieved via reductions in image noise. Fully realising the potential dose reduction of iterative reconstruction requires the adjustment of image factors and forgoing the noise reduction potential of the iterative algorithm. Our study has demonstrated a reduction in radiation dose for some scanning protocols, but not to the extent experimental studies had previously shown or in all protocols expected, raising questions about the extent to which iterative reconstruction achieves dose reduction in real world clinical practice.
Collapse
Affiliation(s)
- Rachael E. Moorin
- School of Public Health, Curtin University, GPO Box U1987, Perth Western Australia, 6845, Australia
- School of Population Health, University of Western Australia, 35 Stirling Highway, Crawley, Perth Western Australia, 6009, Australia
- * E-mail:
| | - David A. J. Gibson
- School of Public Health, Curtin University, GPO Box U1987, Perth Western Australia, 6845, Australia
| | - Rene K. Forsyth
- Department of Medical Imaging Science, Curtin University, GPO Box U1987, Perth, Western Australia, 6845, Australia
| | - Richard Fox
- School of Physics, University of Western Australia, 35 Stirling Highway, Crawley, Perth Western Australia, 6009, Australia
| |
Collapse
|
47
|
|
48
|
|
49
|
Gupta B, Jacob D, Thompson R. Imaging in patients after cardiac transplantation and in patients with ventricular assist devices. J Nucl Cardiol 2015; 22:617-38. [PMID: 25832983 DOI: 10.1007/s12350-015-0115-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 01/29/2015] [Indexed: 02/06/2023]
Abstract
The field of cardiac imaging and the management of patients with severe heart failure have advanced substantially during the past 10 years. Cardiac transplantation offers the best long-term survival with high quality of life for the patients with end stage heart failure. However, acute cardiac rejection and cardiac allograft vasculopathy (CAV) can occur post cardiac transplantation and these problems necessitate regular surveillance. The short-term success of mechanical circulatory support devices (MCSD), such as ventricular assist devices (VADs), in improving survival and quality of life has led to a dramatic growth of the patient population with these devices. The development of optimal imaging techniques and algorithms to evaluate these advanced heart failure patients is evolving and multimodality non-invasive imaging approaches and invasive techniques are commonly employed. Most of the published studies done in the transplant and VAD population are small, and biased based on the strength of the particular program, and there is a relative lack of published protocols to evaluate these patient groups. Moreover, the techniques of echocardiography, computed tomography (CT), magnetic resonance imaging, and nuclear cardiology have all progressed rapidly in recent years. There is thus a knowledge gap for cardiologists, radiologists, and clinicians, especially regarding surveillance for CAV and ideal imaging approaches for patients with VADs. The purpose of this review article is to provide an overview of different noninvasive imaging modalities used to evaluate patients after cardiac transplantation and for patients with VADs. The review focuses on the role of echocardiography, CT, and nuclear imaging in surveillance for CAV and rejection and on the assessment of ventricular structure and function, myocardial remodeling and complications for VAD patients.
Collapse
Affiliation(s)
- Bhanu Gupta
- Department of Cardiology, St. Luke's Mid America Heart Institute, 4330 Wornall Rd, Suite 2000, Kansas City, MO, USA
| | | | | |
Collapse
|
50
|
den Harder AM, Willemink MJ, de Ruiter QMB, Schilham AMR, Krestin GP, Leiner T, de Jong PA, Budde RPJ. Achievable dose reduction using iterative reconstruction for chest computed tomography: A systematic review. Eur J Radiol 2015. [PMID: 26212557 DOI: 10.1016/j.ejrad.2015.07.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES Iterative reconstruction (IR) allows for dose reduction with maintained image quality in CT imaging. In this systematic review the reported effective dose reductions for chest CT and the effects on image quality are investigated. METHODS A systematic search in PubMed and EMBASE was performed. Primary outcome was the reported local reference and reduced effective dose and secondary outcome was the image quality with IR. Both non contrast-enhanced and enhanced studies comparing reference dose with reduced dose were included. RESULTS 24 studies were included. The median number of patients per study was 66 (range 23-200) with in total 1806 patients. The median reported local reference dose of contrast-enhanced chest CT with FBP was 2.6 (range 1.5-21.8) mSv. This decreased to 1.4 (range 0.4-7.3) mSv at reduced dose levels using IR. With non contrast-enhanced chest CT the dose decreased from 3.4 (range 0.7-7.8) mSv to 0.9 (range 0.1-4.5) mSv. Objective mage quality and diagnostic confidence and acceptability remained the same or improved with IR compared to FBP in most studies while data on diagnostic accuracy was limited. CONCLUSION Radiation dose can be reduced to less than 2 mSv for contrast-enhanced chest CT and non contrast-enhanced chest CT is possible at a submillisievert dose using IR algorithms.
Collapse
Affiliation(s)
- Annemarie M den Harder
- Department of Radiology, University Medical Center, PO Box 85500, 3508GA Utrecht, The Netherlands.
| | - Martin J Willemink
- Department of Radiology, University Medical Center, PO Box 85500, 3508GA Utrecht, The Netherlands
| | - Quirina M B de Ruiter
- Department of Vascular Surgery, University Medical Center, PO Box 85500, 3508GA Utrecht, The Netherlands
| | - Arnold M R Schilham
- Department of Radiology, University Medical Center, PO Box 85500, 3508GA Utrecht, The Netherlands
| | - Gabriel P Krestin
- Department of Radiology, Erasmus Medical Center, PO Box 2040, 3000CA Rotterdam, The Netherlands
| | - Tim Leiner
- Department of Radiology, University Medical Center, PO Box 85500, 3508GA Utrecht, The Netherlands
| | - Pim A de Jong
- Department of Radiology, University Medical Center, PO Box 85500, 3508GA Utrecht, The Netherlands
| | - Ricardo P J Budde
- Department of Radiology, Erasmus Medical Center, PO Box 2040, 3000CA Rotterdam, The Netherlands
| |
Collapse
|