1
|
Silov G, Boğa F. A Study of CT-derived Radiation Dose Calculation in Lung Q-SPECT/CT Imaging. Mol Imaging Radionucl Ther 2023; 32:214-220. [PMID: 37870282 PMCID: PMC10600546 DOI: 10.4274/mirt.galenos.2023.55707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 04/02/2023] [Indexed: 10/24/2023] Open
Abstract
Objectives To investigate the amount of effective dose (ED) due to the computed tomography (CT) component of lung perfusion-single-photon emission computed tomography (Q-SPECT)/CT. Methods In this single-center retrospective study, imaging data were collected from the clinic database for the period 2016-2022. The 327 patients identified were aged between 20 and 94 years. Tube voltage, tube current, pitch, gantry rotation time, volume CT dose index, and dose-length product (DLP) were recorded. The DLP was then converted to an ED using the conversion factors. The comparison of the ED between two groups was performed using the Mann-Whitney U non-parametric test. Results ED (mean ± standard deviation, mSv) was 1.20±0.70 for the pulmonary embolism (PE) (-) and 1.54±1.04 for the PE (+) cases (p<0.05). It was observed that there was a 28% increase in the ED for the PE (+) cases. In addition, each of the PE (-) and PE (+) cases was divided into two groups according to the use of the computed tomography dose reduction (CTDR): without CTDR protocol group (non-CTDR) and with CTDR protocol group (CTDR). For those groups, ED were obtained as 0.87±0.72 and 1.55±0.47 for PE (-) cases (p<0.05); 1.56±1.17 and 1.49±0.54 for PE (+) cases (p>0.05) correspondingly. For a deeper understanding, ED was calculated for all three groups formed with different tube voltage values applied for the non-CTDR and CTDR groups.There was a 42% decrease in the ED for group 1 PE (+) compared to group 2 PE (+) (1.21±0.28, 2.07±0.91, p<0.05) and there was a 41% decrease in the ED for group 1 PE (-) compared to group 2 PE (-) cases (1.17±0.32, 1.97±0.65, p<0.05). Conclusion It could be concluded that the effective DR protocol is the non-CTDR protocol for the PE (-) cases and the application of the tube voltage at the level of 100 kVp for the PE (+) cases.
Collapse
Affiliation(s)
- Güler Silov
- Samsun Gazi State Hospital, Clinic of Nuclear Medicine, Samsun, Türkiye
| | - Fatih Boğa
- Samsun Gazi State Hospital, Clinic of Nuclear Medicine, Samsun, Türkiye
| |
Collapse
|
2
|
Rabinowich A, Shendler G, Ben-Sira L, Shiran SI. Pediatric low-dose head CT: Image quality improvement using iterative model reconstruction. Neuroradiol J 2023; 36:555-562. [PMID: 36897057 PMCID: PMC10569199 DOI: 10.1177/19714009231163559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023] Open
Abstract
PURPOSE To evaluate the differences in pediatric non-contrast low-dose head computed tomography (CT) between filtered-back projection and iterative model reconstruction using objective and subjective image quality evaluation. METHODS A retrospective study evaluated children undergoing low-dose non-contrast head CT. All CT scans were reconstructed using both filtered-back projection and iterative model reconstruction. Objective image quality analysis was performed using contrast and signal-to-noise ratios for the supra- and infratentorial brain regions of identical regions of interest on the two reconstruction methods. Two experienced pediatric neuroradiologists evaluated subjective image quality, visibility of structures, and artifacts. RESULTS We evaluated 233 low-dose brain CT scans of 148 pediatric patients. There was a ∼2-fold improvement in the contrast-to-noise ratio between gray and white matter in the infra- and supratentorial regions (p < 0.001) using iterative model reconstruction compared to filtered-back projection. The white and gray matter signal-to-noise ratio improved more than 2-fold using iterative model reconstruction (p < 0.001). Furthermore, radiologists graded anatomical details, gray-white matter differentiation, beam hardening artifacts, and image quality using iterative model reconstructions as superior to filtered-back projection reconstructions. CONCLUSION Iterative model reconstructions had better contrast-to-noise and signal-to-noise ratios with fewer artifacts in pediatric CT brain scans using low-dose radiation protocols. This image quality improvement was demonstrated in the supra- and infratentorial regions. This method thus comprises an important tool for reducing children's exposure while maintaining diagnostic capability.
Collapse
Affiliation(s)
- Aviad Rabinowich
- Department of Radiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Genady Shendler
- Department of Radiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Liat Ben-Sira
- Department of Radiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shelly I Shiran
- Department of Radiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
3
|
Atri PK, Sodhi KS, Bhatia A, Saxena AK, Khandelwal N, Singhi P. Model-based iterative reconstruction in paediatric head computed tomography: a pilot study on dose reduction in children. Pol J Radiol 2021; 86:e504-10. [PMID: 34567298 DOI: 10.5114/pjr.2021.108884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 07/12/2020] [Indexed: 11/30/2022] Open
Abstract
Purpose To evaluate the potential of model-based iterative reconstruction (MBIR) on dose reduction and image quality in children undergoing computed tomography (CT) head examinations. Material and methods This prospective study was approved by the institutional ethics committee. A total of 88 children (age range of 5 to 16 years) with a history of seizures underwent contrast-enhanced CT scan. Forty-one children underwent CT study according to the MBIR technique, while 47 children underwent CT of the head with the non-MBIR protocol. Images were reviewed by 2 blinded paediatric radiologists in a random order. Mean dose-length product, CT dose index (CTDI) volume, and mean effective dose were recorded for both groups. Image quality, image noise, and diagnostic acceptability of 2 image sets were also recorded. Results In the MBIR group, the mean dose-length product was reduced by 79.8%; the mean CTDI volume was reduced by 88.5%, while the mean effective dose was reduced by 81% when compared to the non-MBIR group. No significant difference was seen in diagnostic acceptability, image noise, and image quality between the 2 groups. Conclusions MBIR technique is highly effective in reducing radiation dose in paediatric head CT examinations without any significant difference in image quality, image noise, and diagnostic acceptability.
Collapse
|
4
|
Fu J, Feng F, Quan H, Wan Q, Chen Z, Liu X, Zheng H, Liang D, Cheng G, Hu Z. PWLS-PR: low-dose computed tomography image reconstruction using a patch-based regularization method based on the penalized weighted least squares total variation approach. Quant Imaging Med Surg 2021; 11:2541-2559. [PMID: 34079722 PMCID: PMC8107320 DOI: 10.21037/qims-20-963] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 02/01/2021] [Indexed: 11/06/2022]
Abstract
BACKGROUND Radiation exposure computed tomography (CT) scans and the associated risk of cancer in patients have been major clinical concerns. Existing research can achieve low-dose CT imaging by reducing the X-ray current and the number of projections per rotation of the human body. However, this method may produce excessive noise and fringe artifacts in the traditional filtered back projection (FBP)-reconstructed image. METHODS To solve this problem, iterative image reconstruction is a promising option to obtain high-quality images from low-dose scans. This paper proposes a patch-based regularization method based on penalized weighted least squares total variation (PWLS-PR) for iterative image reconstruction. This method uses neighborhood patches instead of single pixels to calculate the nonquadratic penalty. The proposed regularization method is more robust than the conventional regularization method in identifying random fluctuations caused by sharp edges and noise. Each iteration of the proposed algorithm can be described in the following three steps: image updating via the total variation based on penalized weighted least squares (PWLS-TV), image smoothing, and pixel-by-pixel image fusion. RESULTS Simulation and real-world projection experiments show that the proposed PWLS-PR algorithm achieves a higher image reconstruction performance than similar algorithms. Through the qualitative and quantitative evaluation of simulation experiments, the effectiveness of the method is also verified. CONCLUSIONS Furthermore, this study shows that the PWLS-PR method reduces the amount of projection data required for repeated CT scans and has the useful potential to reduce the radiation dose in clinical medical applications.
Collapse
Affiliation(s)
- Jing Fu
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- College of Electrical and Information Engineering, Hunan University, Changsha, China
| | - Fei Feng
- Department of Radiology, Peking University Shenzhen Hospital, Shenzhen, China
| | - Huimin Quan
- College of Electrical and Information Engineering, Hunan University, Changsha, China
| | - Qian Wan
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, China
| | - Zixiang Chen
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Xin Liu
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Hairong Zheng
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Dong Liang
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Guanxun Cheng
- Department of Radiology, Peking University Shenzhen Hospital, Shenzhen, China
| | - Zhanli Hu
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| |
Collapse
|
5
|
Abstract
INTRODUCTION Due to use of ionization radiation in the computed tomography (CT), optimal parameters should be used to reduce the risk of incidence of secondary cancers in patients who are constantly exposed to x-rays. To reduce the dose delivered to patients in each scan, CT technologists can change the image acquisition parameters. However, this reduces image quality. The present study aimed to optimize and reduce radiation dose in a CT of the paranasal sinuses while minimizing deterioration of image quality. METHODS In this study patients were divided in two groups: Group A was scanned axially and coronally using default parameters, while Group B was scanned axially and coronally using new parameters. Common CT dose descriptors including weighted computed tomography dose index (CTDIw), volumetric CTDI (CTDIvol), dose length product (DLP), effective dose (ED) and image noise were measured for each group. The patients' organ doses were estimated using the ImPACT CT patient Dosimetry Calculator. The tube voltage, tube current, pitch, rotation time, and other parameters were then reduced and optimized. After reconstruction and analysis, all of the images were of good diagnostic quality in both groups Results: Using the new parameters, good agreement was found between the direct and reconstructed images. The CT parameters were reduced by the following proportions: kVp-16.6%, mA-75%, rotation time-20%, and mAs-80%. However, these reductions did not obscure any anatomical landmarks. These parameters reduced the CTDIw, CTDIvol and DLP by 88.2%, 91.3%, and 91.3% respectively. CONCLUSION The results suggest that the use of a Bone algorithm reduces the total amount of radiation used during CT of the sinuses. We recommend using these parameters in children, in the evaluation of facial trauma, and in emergency CT of the paranasal sinuses.
Collapse
Affiliation(s)
- Mohammad Davoudi
- Department of Medical Imaging Center, Babol University of Medical Sciences, Babol, Iran
| | | |
Collapse
|
6
|
Weyland CS, Seker F, Potreck A, Hametner C, Ringleb PA, Möhlenbruch MA, Bendszus M, Pfaff JAR. Radiation exposure per thrombectomy attempt in modern endovascular stroke treatment in the anterior circulation. Eur Radiol 2020; 30:5039-5047. [PMID: 32328765 PMCID: PMC7431433 DOI: 10.1007/s00330-020-06837-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/03/2020] [Accepted: 03/25/2020] [Indexed: 01/03/2023]
Abstract
Objective To quantify radiation exposure (RE) of endovascular stroke treatment (EST) in the anterior circulation per thrombectomy attempt and determine causes for interventions associated with high RE. Methods A retrospective single-center study of an institutional review board−approved stroke database of patients receiving EST for large vessel occlusions in the anterior circulation between January 2013 and April 2018 to evaluate reference levels (RL) per thrombectomy attempt. ESTs with RE above the RL were analyzed to determine causes for high RE. Results Overall, n = 544 patients (occlusion location, M1 and M2 segments of the middle cerebral artery 53.5% and 27.2%, carotid artery 17.6%; successful recanalization rate 85.7%) were analyzed. In the overall population, DAP (in Gy cm2, median (IQR)) was 113.7 (68.9–181.7) with a median fluoroscopy time of 31 min (IQR, 17–53) and a median of 2 (IQR, 1–4) thrombectomy attempts. RE increased significantly with every thrombectomy attempt (DAP1, 68.7 (51.2–106.8); DAP2, 106.4 (84.8–115.6); p value1vs2, < 0.001; DAP3, 130.2 (89.1–183.6); p value2vs3, 0.044; DAP4, 169.9 (128.4–224.1); p value3vs4, 0.001; and DAP5, 227.6 (146.3–294.6); p value4vs5, 0.019). Procedures exceeding the 90th percentile of the attempt-dependent radiation exposure level were associated with procedural complications (n = 17/52, 29.8%) or a difficult vascular access (n = 8/52, 14%). Conclusions Radiation exposure in endovascular stroke treatment is depending on the number of thrombectomy attempts. Radiation exposure doubles when three attempts and triples when five attempts are necessary compared with single-maneuver interventions. Procedural complications and difficult vascular access were associated with a high radiation exposure in this collective. Key Points • Radiation exposure of endovascular stroke treatment (EST) is dependent on the number of thrombectomy attempts. • Reference levels as means for quality control in hospitals performing endovascular stroke treatment should be defined by the number of thrombectomy attempts—we suggest 107 Gy cm2, 156 Gy cm2, 184 Gy cm2, 244 Gy cm2, and 295 Gy cm2for 1 to 5 maneuvers, respectively, for EST of the anterior circulation • Cases with high rates of radiation exposure are associated with periprocedural complications and difficult anatomical access as a probable cause for a high radiation exposure.
Collapse
Affiliation(s)
- Charlotte S Weyland
- Department of Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Fatih Seker
- Department of Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Arne Potreck
- Department of Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Christian Hametner
- Department of Neurology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Peter A Ringleb
- Department of Neurology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Markus A Möhlenbruch
- Department of Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Martin Bendszus
- Department of Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
| | - Johannes A R Pfaff
- Department of Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
| |
Collapse
|
7
|
Chen Z, Zhang Q, Zhou C, Zhang M, Yang Y, Liu X, Zheng H, Liang D, Hu Z. Low-dose CT reconstruction method based on prior information of normal-dose image. J Xray Sci Technol 2020; 28:1091-1111. [PMID: 33044223 DOI: 10.3233/xst-200716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
BACKGROUND Radiation risk from computed tomography (CT) is always an issue for patients, especially those in clinical conditions in which repeated CT scanning is required. For patients undergoing repeated CT scanning, a low-dose protocol, such as sparse scanning, is often used, and consequently, an advanced reconstruction algorithm is also needed. OBJECTIVE To develop a novel algorithm used for sparse-view CT reconstruction associated with the prior image. METHODS A low-dose CT reconstruction method based on prior information of normal-dose image (PI-NDI) involving a transformed model for attenuation coefficients of the object to be reconstructed and prior information application in the forward-projection process was used to reconstruct CT images from sparse-view projection data. A digital extended cardiac-torso (XCAT) ventral phantom and a diagnostic head phantom were employed to evaluate the performance of the proposed PI-NDI method. The root-mean-square error (RMSE), peak signal-to-noise ratio (PSNR) and mean percent absolute error (MPAE) of the reconstructed images were measured for quantitative evaluation of the proposed PI-NDI method. RESULTS The reconstructed images with sparse-view projection data via the proposed PI-NDI method have higher quality by visual inspection than that via the compared methods. In terms of quantitative evaluations, the RMSE measured on the images reconstructed by the PI-NDI method with sparse projection data is comparable to that by MLEM-TV, PWLS-TV and PWLS-PICCS with fully sampled projection data. When the projection data are very sparse, images reconstructed by the PI-NDI method have higher PSNR values and lower MPAE values than those from the compared algorithms. CONCLUSIONS This study presents a new low-dose CT reconstruction method based on prior information of normal-dose image (PI-NDI) for sparse-view CT image reconstruction. The experimental results validate that the new method has superior performance over other state-of-art methods.
Collapse
Affiliation(s)
- Zixiang Chen
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Qiyang Zhang
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Chao Zhou
- Department of Nuclear Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Mengxi Zhang
- Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Yongfeng Yang
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Xin Liu
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Hairong Zheng
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Dong Liang
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Zhanli Hu
- Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| |
Collapse
|
8
|
Zeng Z, Dong Y, Hua Q, Kuang X, Li K, Deng X, Qiu S. Computed tomography perfusion study evaluating the curative effect of tibial transverse transport in patients with severe diabetic foot. J Orthop Translat 2019; 19:133-142. [PMID: 31844621 PMCID: PMC6896675 DOI: 10.1016/j.jot.2019.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 03/26/2019] [Accepted: 04/03/2019] [Indexed: 11/24/2022] Open
Abstract
Background The clinical treatment of patients with severe diabetic foot (DF) is difficult. Recently, the First Affiliated Hospital of Guangxi Medical University began to apply tibial transverse transport (TTT) in patients with DF. This treatment has achieved significant effects, but its mechanism of action is unclear. Recently, microcirculation and the pathogenesis of diabetes have become the foci of research in this field. The evaluation of the possible mechanism of microcirculation reconstruction requires relevant indicators. The aim of this study was to investigate the value of computed tomography perfusion in evaluations of the curative effects of TTT and establish corresponding quantitative evaluation indicators. Methods Twelve patients with DF treated with TTT were recruited as the research participants. All diabetic feet were divided into the transport foot (TF) group and nontransport foot (NTF) group according to whether the patients underwent TTT. All patients underwent CT shuttle scanning preoperatively and 8 weeks after surgery. The shuttle scan data were transferred to Siemens VPCT body software and postprocessed with Customized Tumor2. We chose the TF posterior tibial artery from a distance of approximately 15 cm to the bifurcation of the plantar medial artery and the lateral plantar artery as the input artery. We selected the centre of the bilateral medial plantar muscle group on the coronal and axial regions of interest. We applied a deconvolution approach to obtain data from both sides of the plantar tissue perfusion. Skin temperature (ST) detection was performed with an ST gun to measure the average ST values in the dorsal and plantar areas, the first and fifth heads of the phalanges, and the medial and lateral malleolus points of both feet of patients with DF preoperatively and 8 weeks after surgery. Results The preoperative and postoperative ST values of the patients in the TF group were 30.73 ± 1.86 °C and 32.22 ± 1.51 °C, respectively. The preoperative and postoperative ST values for the patients in the NTF group were 30.93 ± 2.65 °C and 32.07 ± 2.09 °C, respectively. There were significant differences in the preoperative and postoperative data between the TF (P = 0.001) and NTF (P = 0.013) groups. In the patients with DF who underwent TTT, there were both preoperative and postoperative differences inside the medial plantar muscle group in the relative blood volume (rBV) value and relative mean transit time (rMTT) (P = 0.027, P = 0.026, respectively). The postoperative BV in the NTF group was increased compared with the preoperative BV (P = 0.006). Conclusion There were significant differences in relative BV, relative mean transit time, and ST between the two groups before and after surgery, and the postoperative BV in the NTF group and ST values in the two groups were increased compared with the preoperative values. The BV in the NTF group and the ST values in the two groups were effective indicators in evaluating the changes between preoperative and postoperative perfusion. These results indicate that TTT could increase plantar tissue perfusion as assessed by BV and ST; this increase was among the reasons for the surface healing of severe DF ulcers. Translational potential of this article Preoperative CT perfusion evaluation can provide relevant information of blood vessels and microcirculation for clinical operation, and postoperative CT perfusion evaluation can provide postoperative efficacy evaluation for clinical operation. All patients received information about the study and signed a specific informed consent. Approval for this study was granted by the regional ethics committee [Regional Ethics Committee of the First Affiliated Hospital of Guangxi Medical University, China [(2018-(KY-E-069].
Collapse
Affiliation(s)
- Zisan Zeng
- Department of Radiology, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, China
| | - Yan Dong
- Department of Radiology, Affiliated Hospital of Guilin Medical University, Guilin Medical University, Guilin, China
| | - Qikai Hua
- Department of Orthopedics, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, China
| | | | - Kai Li
- Department of Radiology, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, China
| | - Xianyu Deng
- Department of Cardiovascular, The Second People's Hospital, Guilin, China
| | - Shaohua Qiu
- Department of Radiology, The First Hospital of Putian City, Putian, China
| |
Collapse
|
9
|
Chung MS, Choi YJ, Hwang JY, Yoon DH, Seo KJ, Lee JH, Baek JH. Feasibility of reduced-dose CT of the head and neck with iterative reconstruction: a phantom and prospective clinical study. Acta Radiol 2019; 60:1457-1464. [PMID: 30776905 DOI: 10.1177/0284185119830276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Mi Sun Chung
- Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Young Jun Choi
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
| | - Jae-Yeon Hwang
- Department of Radiology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Gyeonsangnam-do, Republic of Korea
| | - Dok Hyun Yoon
- Department of Oncology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
| | - Kyeong Jin Seo
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
| | - Jeong Hyun Lee
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
| | - Jung Hwan Baek
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
| |
Collapse
|
10
|
Morotti A, Boulouis G, Dowlatshahi D, Li Q, Barras CD, Delcourt C, Yu Z, Zheng J, Zhou Z, Aviv RI, Shoamanesh A, Sporns PB, Rosand J, Greenberg SM, Al-Shahi Salman R, Qureshi AI, Demchuk AM, Anderson CS, Goldstein JN, Charidimou A. Standards for Detecting, Interpreting, and Reporting Noncontrast Computed Tomographic Markers of Intracerebral Hemorrhage Expansion. Ann Neurol 2019; 86:480-492. [PMID: 31364773 DOI: 10.1002/ana.25563] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 02/05/2023]
Abstract
Significant hematoma expansion (HE) affects one-fifth of people within 24 hours after acute intracerebral hemorrhage (ICH), and its prevention is an appealing treatment target. Although the computed tomography (CT)-angiography spot sign predicts HE, only a minority of ICH patients receive contrast injection. Conversely, noncontrast CT (NCCT) is used to diagnose nearly all ICH, so NCCT markers represent a widely available alternative for prediction of HE. However, different NCCT signs describe similar features, with lack of consensus on the optimal image acquisition protocol, assessment, terminology, and diagnostic criteria. In this review, we propose practical guidelines for detecting, interpreting, and reporting NCCT predictors of HE. ANN NEUROL 2019;86:480-492.
Collapse
Affiliation(s)
- Andrea Morotti
- Department of Neurology and Neurorehabilitation, IRCCS Mondino Foundation, Pavia, Italy
| | - Gregoire Boulouis
- Université de Paris, INSERM UMR 1266 IMA-BRAIN, Department of Neuroradiology, Centre Hospitalier Sainte Anne, Paris, France
| | - Dar Dowlatshahi
- Department of Medicine (Neurology), University of Ottawa, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | - Qi Li
- Department of Neurology, First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Christen D Barras
- South Australian Health and Medical Research Institute and Department of Radiology, Royal Adelaide Hospital and University of Adelaide, Adelaide, South Australia, Australia
| | - Candice Delcourt
- Department of Neurology, Royal Prince Alfred Hospital, Sydney Health Partners, University of Sydney, Sydney, New South Wales, Australia.,George Institute for Global Health, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Zhiyuan Yu
- Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, China
| | - Jun Zheng
- Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, China
| | - Zien Zhou
- George Institute for Global Health, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.,Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Richard I Aviv
- Division of Neuroradiology and Department of Medical Imaging, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Ashkan Shoamanesh
- Division of Neurology, McMaster University/Population Health Research Institute, Hamilton, Ontario, Canada
| | - Peter B Sporns
- Institute of Clinical Radiology, University of Münster, Münster, Germany
| | - Jonathan Rosand
- J. P. Kistler Stroke Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA.,Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA.,Henry and Allison McCance Center for Brain Health, Massachusetts General Hospital, Boston, MA
| | - Steven M Greenberg
- J. P. Kistler Stroke Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | | | | | - Andrew M Demchuk
- Department of Clinical Neurosciences, Department of Radiology, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Craig S Anderson
- Department of Neurology, Royal Prince Alfred Hospital, Sydney Health Partners, University of Sydney, Sydney, New South Wales, Australia.,George Institute for Global Health, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Joshua N Goldstein
- J. P. Kistler Stroke Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA.,Division of Neurocritical Care and Emergency Neurology, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA.,Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Andreas Charidimou
- J. P. Kistler Stroke Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | | |
Collapse
|
11
|
Southard RN, Bardo DME, Temkit MH, Thorkelson MA, Augustyn RA, Martinot CA. Comparison of Iterative Model Reconstruction versus Filtered Back-Projection in Pediatric Emergency Head CT: Dose, Image Quality, and Image-Reconstruction Times. AJNR Am J Neuroradiol 2019; 40:866-871. [PMID: 30975652 DOI: 10.3174/ajnr.a6034] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 02/27/2019] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Noncontrast CT of the head is the initial imaging test for traumatic brain injury, stroke, or suspected nonaccidental trauma. Low-dose head CT protocols using filtered back-projection are susceptible to increased noise and decreased image quality. Iterative reconstruction noise suppression allows the use of lower-dose techniques with maintained image quality. We review our experience with children undergoing emergency head CT examinations reconstructed using knowledge-based iterative model reconstruction versus standard filtered back-projection, comparing reconstruction times, radiation dose, and objective and subjective image quality. MATERIALS AND METHODS This was a retrospective study comparing 173 children scanned using standard age-based noncontrast head CT protocols reconstructed with filtered back-projection with 190 children scanned using low-dose protocols reconstructed with iterative model reconstruction. ROIs placed on the frontal white matter and thalamus yielded signal-to-noise and contrast-to-noise ratios. Volume CT dose index and study reconstruction times were recorded. Random subgroups of patients were selected for subjective image-quality review. RESULTS The volume CT dose index was significantly reduced in studies reconstructed with iterative model reconstruction compared with filtered back-projection, (mean, 24.4 ± 3.1 mGy versus 31.1 ± 6.0 mGy, P < .001), while the SNR and contrast-to-noise ratios improved 2-fold (P < .001). Radiologists graded iterative model reconstruction images as superior to filtered back-projection images for gray-white matter differentiation and anatomic detail (P < .001). The average reconstruction time of the filtered back-projection studies was 101 seconds, and with iterative model reconstruction, it was 147 seconds (P < .001), without a practical effect on work flow. CONCLUSIONS In children referred for emergency noncontrast head CT, optimized low-dose protocols with iterative model reconstruction allowed us to significantly reduce the relative dose, on average, 22% compared with filtered back-projection, with significantly improved objective and subjective image quality.
Collapse
Affiliation(s)
- R N Southard
- From the Departments of Medical Imaging (R.N.S., D.M.E.B., M.A.T., R.A.A., C.A.M.)
| | - D M E Bardo
- From the Departments of Medical Imaging (R.N.S., D.M.E.B., M.A.T., R.A.A., C.A.M.)
| | - M H Temkit
- Clinical Research (M.H.T.), Phoenix Children's Hospital, Phoenix Arizona
| | - M A Thorkelson
- From the Departments of Medical Imaging (R.N.S., D.M.E.B., M.A.T., R.A.A., C.A.M.)
| | - R A Augustyn
- From the Departments of Medical Imaging (R.N.S., D.M.E.B., M.A.T., R.A.A., C.A.M.)
| | - C A Martinot
- From the Departments of Medical Imaging (R.N.S., D.M.E.B., M.A.T., R.A.A., C.A.M.)
| |
Collapse
|
12
|
Slavine NV, Mccoll RW, Oz OK, Guild J, Anderson JA, Lenkinski RE. Phantom and Preclinical Studies for Image Improvement in Clinical CT. IEEE Trans Radiat Plasma Med Sci 2019. [DOI: 10.1109/trpms.2018.2873187] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
13
|
Yabuuchi H, Kamitani T, Sagiyama K, Yamasaki Y, Matsuura Y, Hino T, Tsutsui S, Kondo M, Shirasaka T, Honda H. Clinical application of radiation dose reduction for head and neck CT. Eur J Radiol 2018; 107:209-15. [DOI: 10.1016/j.ejrad.2018.08.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 08/14/2018] [Accepted: 08/23/2018] [Indexed: 12/12/2022]
|
14
|
Abstract
OBJECTIVE To determine if the lumbar spine can be accurately evaluated on an abdominal CT. METHODS The electronic medical records at our institution were searched to find all consecutive patients who had an abdominal CT within 12 months of a lumbar spine MRI obtained between 01 November 2010 and 31 October 2015. The abdominal CT studies were retrospectively reviewed in a blinded fashion for the presence of any significant lumbar spine abnormalities. The prospective lumbar spine MRI reports were used as the standard of reference. RESULTS 5,031 patients had lumbar spine MRI studies at our institution during the study period of 01 November 2010 to 31 October 2015. 144 patients met the inclusion criteria of our study. No patients were excluded. 107 patients had 256 abnormal findings on the lumbar spine MRI studies. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of abdominal CT in lumbar spine evaluation on a per patient/per finding basis were 89.7/95.3%, 97.3/100%, 99.0/99.2%, 76.6/99.8% and 91.7/99.8%, respectively. CONCLUSION Despite several limitations (e.g. spinal cord assessment, bone marrow assessment and quantum mottle) compared with evaluation of the lumbar spine using MRI, evaluation of the lumbar spine on abdominal CT studies can be accurately performed with current state of the art CT scanners. Additional prospective studies are needed for a more definitive analysis. Advances in knowledge: With recent advances in CT technology, accurate evaluation of the lumbar spine on abdominal CT studies is feasible, potentially providing significant additional information to patients without additional imaging.
Collapse
Affiliation(s)
- Mitchell A Klein
- Department of Radiology, Milwaukee VA Medical Center, 5000 West National Avenue, Milwaukee, WI 53295-1000, WI, USA
| |
Collapse
|
15
|
Cros M, Joemai RMS, Geleijns J, Molina D, Salvadó M. SimDoseCT: dose reporting software based on Monte Carlo simulation for a 320 detector-row cone-beam CT scanner and ICRP computational adult phantoms. ACTA ACUST UNITED AC 2017; 62:6304-6321. [DOI: 10.1088/1361-6560/aa77ea] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
16
|
Harris MA, Huckle J, Anthony D, Charnock P. The Acceptability of Iterative Reconstruction Algorithms in Head CT: An Assessment of Sinogram Affirmed Iterative Reconstruction (SAFIRE) vs. Filtered Back Projection (FBP) Using Phantoms. J Med Imaging Radiat Sci 2017; 48:259-269. [PMID: 31047408 DOI: 10.1016/j.jmir.2017.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 04/05/2017] [Accepted: 04/11/2017] [Indexed: 11/25/2022]
Abstract
BACKGROUND Computed tomography (CT) is the primary imaging investigation for many neurologic conditions with a proportion of patients incurring cumulative doses. Iterative reconstruction (IR) allows dose optimization, but head CT presents unique image quality complexities and may lead to strong reader preferences. OBJECTIVES This study evaluates the relationships between image quality metrics, image texture, and applied radiation dose within the context of IR head CT protocol optimization in the simulated patient setting. A secondary objective was to determine the influence of optimized protocols on diagnostic confidence using a custom phantom. METHODS AND SETTING A three-phase phantom study was performed to characterize reconstruction methods at the local reference standard and a range of exposures. CT numbers and pixel noise were quantified supplemented by noise uniformity, noise power spectrum, contrast-to-noise ratio (CNR), high- and low-contrast resolution. Reviewers scored optimized protocol images based on established reporting criteria. RESULTS Increasing strengths of IR resulted in lower pixel noise, lower noise variance, and increased CNR. At the reference standard, the image noise was reduced by 1.5 standard deviation and CNR increased by 2.0. Image quality was maintained at ≤24% relative dose reduction. With the exception of image sharpness, there were no significant differences between grading for IR and filtered back projection reconstructions. CONCLUSIONS IR has the potential to influence pixel noise, CNR, and noise variance (image texture); however, systematically optimized IR protocols can maintain the image quality of filtered back projection. This work has guided local application and acceptance of lower dose head CT protocols.
Collapse
Affiliation(s)
- Martine A Harris
- Radiology Department, Mid Yorkshire Hospitals NHS Trust, Pinderfields General Hospital, Wakefield, UK.
| | - John Huckle
- School of Healthcare, Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Denis Anthony
- School of Healthcare, Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Paul Charnock
- Integrated Radiological Services Ltd., Liverpool, UK
| |
Collapse
|
17
|
Sookpeng S, Butdee C. Signal-to-noise ratio and dose to the lens of the eye for computed tomography examination of the brain using an automatic tube current modulation system. Emerg Radiol 2017; 24:233-9. [PMID: 27909929 DOI: 10.1007/s10140-016-1470-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 11/15/2016] [Indexed: 10/24/2022]
Abstract
PURPOSE The study aimed to evaluate the image quality in terms of signal-to-noise ratio (SNR) and dose to the lens of the eye and the other nearby organs from the CT brain scan using an automatic tube current modulation (ATCM) system with or without CT gantry tilt is needed. METHODS An anthropomorphic phantom was scanned with different settings including use of different ATCM, fixed tube current time product (mAs) settings and degree angles of gantry tilt. Gafchromic film XR-QA2 was used to measure absorbed dose of the organs. Relative doses and SNR for the various scan settings were compared with the reference setting of the fixed 330 mAs. RESULTS Average absorbed dose for the lens of the eyes varied from 8.7 to 21.7 mGy. The use of the ATCM system with the gantry tilt resulted in up to 60% decrease in the dose to the lens of the eye. SNR significantly decreased while tilting the gantry using the fixed mAs techniques, compared to that of the reference setting. However, there were no statistical significant differences for SNRs between the reference setting and all ATCM settings. CONCLUSIONS Compared to the reference setting of the fixed effective mAs, using the ATCM system and appropriate tilting, the gantry resulted in a substantial decrease in the dose to the lens of the eye while preserving signal-to-noise ratio. CT brain examination should be carefully controlled to optimize dose for lens of the eye and image quality of the examination.
Collapse
|
18
|
Morotti A, Romero JM, Jessel MJ, Brouwers HB, Gupta R, Schwab K, Vashkevich A, Ayres A, Anderson CD, Gurol ME, Viswanathan A, Greenberg SM, Rosand J, Goldstein JN. Effect of CTA Tube Current on Spot Sign Detection and Accuracy for Prediction of Intracerebral Hemorrhage Expansion. AJNR Am J Neuroradiol 2016; 37:1781-1786. [PMID: 27197985 DOI: 10.3174/ajnr.a4810] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 03/17/2016] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Reduction of CT tube current is an effective strategy to minimize radiation load. However, tube current is also a major determinant of image quality. We investigated the impact of CTA tube current on spot sign detection and diagnostic performance for intracerebral hemorrhage expansion. MATERIALS AND METHODS We retrospectively analyzed a prospectively collected cohort of consecutive patients with primary intracerebral hemorrhage from January 2001 to April 2015 who underwent CTA. The study population was divided into 2 groups according to the median CTA tube current level: low current (<350 mA) and high current (≥350 mA). CTA first-pass readings for spot sign presence were independently analyzed by 2 readers. Baseline and follow-up hematoma volumes were assessed by semiautomated computer-assisted volumetric analysis. Sensitivity, specificity, positive and negative predictive values, and accuracy of spot sign in predicting hematoma expansion were calculated. RESULTS This study included 709 patients (288 and 421 in the low- and high-current groups, respectively). A higher proportion of low-current scans identified at least 1 spot sign (20.8% versus 14.7%, P = .034), but hematoma expansion frequency was similar in the 2 groups (18.4% versus 16.2%, P = .434). Sensitivity and positive and negative predictive values were not significantly different between the 2 groups. Conversely, high-current scans showed superior specificity (91% versus 84%, P = .015) and overall accuracy (84% versus 77%, P = .038). CONCLUSIONS CTA obtained at high levels of tube current showed better diagnostic accuracy for prediction of hematoma expansion by using spot sign. These findings may have implications for future studies using the CTA spot sign to predict hematoma expansion for clinical trials.
Collapse
Affiliation(s)
- A Morotti
- From the Department of Clinical and Experimental Sciences (A.M.), Neurology Clinic, University of Brescia, Brescia, Italy
- J.P. Kistler Stroke Research Center (A.M., M.J.J., K.S., A. Vashkevich, A.A., C.D.A., M.E.G., A. Viswanathan, S.M.G., J.R., J.N.G.)
| | - J M Romero
- Neuroradiology Service, Department of Radiology (J.M.R., R.G.)
| | - M J Jessel
- J.P. Kistler Stroke Research Center (A.M., M.J.J., K.S., A. Vashkevich, A.A., C.D.A., M.E.G., A. Viswanathan, S.M.G., J.R., J.N.G.)
| | - H B Brouwers
- Department of Neurosurgery (H.B.B.), Brain Center Rudolf Magnus, University Medical Center, Utrecht, the Netherlands
| | - R Gupta
- Neuroradiology Service, Department of Radiology (J.M.R., R.G.)
| | - K Schwab
- J.P. Kistler Stroke Research Center (A.M., M.J.J., K.S., A. Vashkevich, A.A., C.D.A., M.E.G., A. Viswanathan, S.M.G., J.R., J.N.G.)
| | - A Vashkevich
- J.P. Kistler Stroke Research Center (A.M., M.J.J., K.S., A. Vashkevich, A.A., C.D.A., M.E.G., A. Viswanathan, S.M.G., J.R., J.N.G.)
| | - A Ayres
- J.P. Kistler Stroke Research Center (A.M., M.J.J., K.S., A. Vashkevich, A.A., C.D.A., M.E.G., A. Viswanathan, S.M.G., J.R., J.N.G.)
| | - C D Anderson
- J.P. Kistler Stroke Research Center (A.M., M.J.J., K.S., A. Vashkevich, A.A., C.D.A., M.E.G., A. Viswanathan, S.M.G., J.R., J.N.G.)
| | - M E Gurol
- J.P. Kistler Stroke Research Center (A.M., M.J.J., K.S., A. Vashkevich, A.A., C.D.A., M.E.G., A. Viswanathan, S.M.G., J.R., J.N.G.)
| | - A Viswanathan
- J.P. Kistler Stroke Research Center (A.M., M.J.J., K.S., A. Vashkevich, A.A., C.D.A., M.E.G., A. Viswanathan, S.M.G., J.R., J.N.G.)
| | - S M Greenberg
- J.P. Kistler Stroke Research Center (A.M., M.J.J., K.S., A. Vashkevich, A.A., C.D.A., M.E.G., A. Viswanathan, S.M.G., J.R., J.N.G.)
| | - J Rosand
- J.P. Kistler Stroke Research Center (A.M., M.J.J., K.S., A. Vashkevich, A.A., C.D.A., M.E.G., A. Viswanathan, S.M.G., J.R., J.N.G.)
- Division of Neurocritical Care and Emergency Neurology (J.R., J.N.G.)
| | - J N Goldstein
- J.P. Kistler Stroke Research Center (A.M., M.J.J., K.S., A. Vashkevich, A.A., C.D.A., M.E.G., A. Viswanathan, S.M.G., J.R., J.N.G.)
- Division of Neurocritical Care and Emergency Neurology (J.R., J.N.G.)
- Department of Emergency Medicine (J.N.G.), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| |
Collapse
|
19
|
Ni QQ, Chen GZ, Schoepf UJ, Klitsie MAJ, De Cecco CN, Zhou CS, Luo S, Lu GM, Zhang LJ. Cerebral CTA with Low Tube Voltage and Low Contrast Material Volume for Detection of Intracranial Aneurysms. AJNR Am J Neuroradiol 2016; 37:1774-1780. [PMID: 27151751 DOI: 10.3174/ajnr.a4803] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 03/06/2016] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Multidetector row CTA has become the primary imaging technique for detecting intracranial aneurysms. Technical progress enables the use of cerebral CTA with lower radiation doses and contrast media. We evaluated the diagnostic accuracy of 80-kV(peak) cerebral CTA with 30 mL of contrast agent for detecting intracranial aneurysms. MATERIALS AND METHODS Two hundred four patients were randomly divided into 2 groups. Patients in group A (n = 102) underwent 80-kVp CTA with 30 mL of contrast agent, while patients in group B (n = 102) underwent conventional CTA (120 kVp, 60 mL of contrast agent). All patients underwent DSA. Image quality, diagnostic accuracy, and radiation dose between the 2 groups were compared. RESULTS Diagnostic image quality was obtained in 100 and 99 patients in groups A and B, respectively (P = .65). With DSA as reference standard, diagnostic accuracy on a per-aneurysm basis was 89.9% for group A and 93.9% for group B. For evaluating smaller aneurysms (<3 mm), the diagnostic accuracy of groups A and B was 86.3% and 90.8%, respectively. There was no difference in diagnostic accuracy between each CTA group and DSA (all, P > .05) or between the 2 CTA groups (all, P > .05). The effective dose in group A was reduced by 72.7% compared with group B. CONCLUSIONS In detecting intracranial aneurysms with substantial radiation dose and contrast agent reduction, 80-kVp/30-mL contrast CTA provides the same diagnostic accuracy as conventional CTA.
Collapse
Affiliation(s)
- Q Q Ni
- From the Department of Medical Imaging (Q.Q.N., G.Z.C., C.S.Z., S.L., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - G Z Chen
- From the Department of Medical Imaging (Q.Q.N., G.Z.C., C.S.Z., S.L., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - U J Schoepf
- Department of Radiology and Radiological Science (U.J.S., M.A.J.K., C.N.D.C.), Medical University of South Carolina, Charleston, South Carolina
| | - M A J Klitsie
- Department of Radiology and Radiological Science (U.J.S., M.A.J.K., C.N.D.C.), Medical University of South Carolina, Charleston, South Carolina
| | - C N De Cecco
- Department of Radiology and Radiological Science (U.J.S., M.A.J.K., C.N.D.C.), Medical University of South Carolina, Charleston, South Carolina
| | - C S Zhou
- From the Department of Medical Imaging (Q.Q.N., G.Z.C., C.S.Z., S.L., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - S Luo
- From the Department of Medical Imaging (Q.Q.N., G.Z.C., C.S.Z., S.L., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - G M Lu
- From the Department of Medical Imaging (Q.Q.N., G.Z.C., C.S.Z., S.L., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - L J Zhang
- From the Department of Medical Imaging (Q.Q.N., G.Z.C., C.S.Z., S.L., G.M.L., L.J.Z.), Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| |
Collapse
|
20
|
Morotti A, Romero JM, Gupta R, Goldstein JN. Reply. AJNR Am J Neuroradiol 2016; 37:E64. [PMID: 27444941 DOI: 10.3174/ajnr.a4887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- A Morotti
- Department of Clinical and Experimental Sciences, Neurology Clinic University of Brescia, Brescia, Italy.,J. P. Kistler Stroke Research Center Massachusetts General Hospital, Harvard Medical SchoolBoston, Massachusetts
| | - J M Romero
- Neuroradiology Service, Department of Radiology Massachusetts General Hospital, Harvard Medical School Boston, Massachusetts
| | - R Gupta
- Neuroradiology Service, Department of Radiology Massachusetts General Hospital, Harvard Medical School Boston, Massachusetts
| | - J N Goldstein
- J. P. Kistler Stroke Research Center.,Department of Emergency Medicine Massachusetts General Hospital, Harvard Medical School Boston, Massachusetts
| |
Collapse
|
21
|
Jang J, Jung SE, Jeong WK, Lim YS, Choi JI, Park MY, Kim Y, Lee SK, Chung JJ, Eo H, Yong HS, Hwang SS. Radiation Doses of Various CT Protocols: a Multicenter Longitudinal Observation Study. J Korean Med Sci 2016; 31 Suppl 1:S24-31. [PMID: 26908984 PMCID: PMC4756338 DOI: 10.3346/jkms.2016.31.s1.s24] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Accepted: 11/23/2015] [Indexed: 11/25/2022] Open
Abstract
Emerging concerns regarding the hazard from medical radiation including CT examinations has been suggested. The purpose of this study was to observe the longitudinal changes of CT radiation doses of various CT protocols and to estimate the long-term efforts of supervising radiologists to reduce medical radiation. Radiation dose data from 11 representative CT protocols were collected from 12 hospitals. Attending radiologists had collected CT radiation dose data in two time points, 2007 and 2010. They collected the volume CT dose index (CTDIvol) of each phase, number of phases, dose length product (DLP) of each phase, and types of scanned CT machines. From the collected data, total DLP and effective dose (ED) were calculated. CTDIvol, total DLP, and ED of 2007 and 2010 were compared according to CT protocols, CT machine type, and hospital. During the three years, CTDIvol had significantly decreased, except for dynamic CT of the liver. Total DLP and ED were significantly decreased in all 11 protocols. The decrement was more evident in newer CT scanners. However, there was substantial variability of changes of ED during the three years according to hospitals. Although there was variability according to protocols, machines, and hospital, CT radiation doses were decreased during the 3 years. This study showed the effects of decreased CT radiation dose by efforts of radiologists and medical society.
Collapse
Affiliation(s)
- Jinhee Jang
- Department of Radiology, Seoul St. Mary’s Hospital, College of Medicine, the Catholic University of Korea, Seoul, Korea
| | - Seung Eun Jung
- Department of Radiology, Seoul St. Mary’s Hospital, College of Medicine, the Catholic University of Korea, Seoul, Korea
| | - Woo Kyoung Jeong
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Korea
| | - Yeon Soo Lim
- Department of Radiology, Bucheon St. Mary’s Hospital, College of Medicine, the Catholic University of Korea, Bucheon, Korea
| | - Joon-Il Choi
- Department of Radiology, Seoul St. Mary’s Hospital, College of Medicine, the Catholic University of Korea, Seoul, Korea
| | - Michael Yong Park
- Department of Radiology, Seoul St. Mary’s Hospital, College of Medicine, the Catholic University of Korea, Seoul, Korea
| | - Yongsoo Kim
- Department of Radiology, Hanyang University Guri Hospital, College of Medicine, Hanyang University, Guri, Korea
| | - Seung-Koo Lee
- Department of Radiology, Severance Hospital, College of Medicine, Yonsei University, Seoul, Korea
| | - Jae-Joon Chung
- Department of Radiology, Gangnam Severance Hospital, College of Medicine, Yonsei University, Seoul, Korea
| | - Hong Eo
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University, School of Medicine, Seoul, Korea
| | - Hwan Seok Yong
- Department of Radiology, Korea University Guro Hospital, College of Medicine, Korea University, Seoul, Korea
| | - Sung Su Hwang
- Department of Radiology, St. Vincent’s Hospital, College of Medicine, the Catholic University of Korea, Suwon, Korea
| |
Collapse
|
22
|
Sulagaesuan C, Saksobhavivat N, Asavaphatiboon S, Kaewlai R. Reducing emergency CT radiation doses with simple techniques: A quality initiative project. J Med Imaging Radiat Oncol 2015; 60:23-34. [PMID: 26597510 DOI: 10.1111/1754-9485.12410] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 09/20/2015] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Use of indication-specific CT protocols and adjustment of scan parameters to decrease radiation exposure may result in significant dose reduction. We implemented these strategies and compare pre- and post-implementation radiation dose in emergency department (ED) patients. METHOD This was a descriptive, retrospective study. Patients older than 15 years who had undergone emergency CT examinations of the head, chest, abdomen, pelvis and abdominopelvic region in periods before and after dose-reduction implementation were included. The primary outcome was volume CT dose index (CTDIvol ) and dose length products (DLP). RESULTS There were 786 studies in the pre-implementation (group 1) and 955 studies in the post-implementation (group 2) periods. Radiation dose from all CT types significantly reduced in the post-implementation period. Average CTDIvol for head, chest, abdomen, pelvis and abdominopelvic region (doses during pre-implementation period in parentheses) were 51.5 (109), 8.1 (30.4), 13.1 (41.8), 11 (38), 11.2 (41.8) mGy, respectively. Average DLP was also significantly lower (pre-implementation dose in parentheses) in all CT types, which were 943 (2232), 324 (2517), 944 (5605), 280 (4024), 809 (7118) mGy●cm, respectively. Patients' age, gender, body mass index and size were not significantly different between the two groups. Image quality decreased but almost all examinations received an acceptable diagnostic subjective image quality. CONCLUSION Simple methods could help significantly reduce CT radiation exposure in ED patients while maintaining an acceptable level of diagnostic image quality.
Collapse
Affiliation(s)
- Chakkarat Sulagaesuan
- Department of Diagnostic and Therapeutic Radiology, Ramathibodi Hospital Mahidol University, Bangkok, Thailand
| | - Nitima Saksobhavivat
- Department of Diagnostic and Therapeutic Radiology, Ramathibodi Hospital Mahidol University, Bangkok, Thailand
| | - Sawwanee Asavaphatiboon
- Department of Diagnostic and Therapeutic Radiology, Ramathibodi Hospital Mahidol University, Bangkok, Thailand
| | - Rathachai Kaewlai
- Department of Diagnostic and Therapeutic Radiology, Ramathibodi Hospital Mahidol University, Bangkok, Thailand
| |
Collapse
|
23
|
Lin CJ, Mok GSP, Tsai MF, Tsai WT, Yang BH, Tu CY, Wu TH. National Survey of Radiation Dose and Image Quality in Adult CT Head Scans in Taiwan. PLoS One 2015; 10:e0131243. [PMID: 26125549 PMCID: PMC4488422 DOI: 10.1371/journal.pone.0131243] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 05/30/2015] [Indexed: 11/18/2022] Open
Abstract
Introduction The purpose of the present study was to evaluate the influence of different variables on radiation dose and image quality based on a national database. Materials and Methods Taiwan’s Ministry of Health and Welfare requested all radiology departments to complete a questionnaire for each of their CT scanners. Information gathered included all scanning parameters for CT head scans. For the present analysis, CT machines were divided into three subgroups: single slice CT (Group A); multi-detector CT (MDCT) with 2-64 slices (Group B); and MDCT with more than 64 slices (Group C). Correlations between computed tomography dose index (CTDI) and signal-to-noise ratio (SNR) with cumulated tube rotation number (CTW(n)) and cumulated tube rotation time (CTW(s)), and sub group analyses of CTDI and SNR across the three groups were performed. Results CTDI values demonstrated a weak correlation (r = 0.33) with CTW(n) in Group A. SNR values demonstrated a weak negative correlation (r = -0.46) with CTW(n) in Group C. MDCT with higher slice numbers used more tube potential resulting in higher effective doses. There were both significantly lower CTDI and SNR values in helical mode than in axial mode in Group B, but not Group C. Conclusion CTW(n) and CTW(s) did not influence radiation output. Helical mode is more often used in MDCT and results in both lower CTDI and SNR compared to axial mode in MDCT with less than 64 slices.
Collapse
Affiliation(s)
- Chung-Jung Lin
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Greta S. P. Mok
- Biomedical Imaging Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau, China
| | - Mang-Fen Tsai
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan
| | - Wei-Ta Tsai
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan
- Department of Radiation Oncology, Tzu Chi General Hospital Dalin Branch, Chiayi, Taiwan
- Association of Medical Radiation Technologists, Taipei, Taiwan
| | - Bang-Hung Yang
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan
- Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Association of Medical Radiation Technologists, Taipei, Taiwan
| | - Chun-Yuan Tu
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan
- Department of Radiology, Mackay Memorial Hospital, Taipei, Taiwan
- Association of Medical Radiation Technologists, Taipei, Taiwan
- * E-mail: (THW); (CYT)
| | - Tung-Hsin Wu
- Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan
- * E-mail: (THW); (CYT)
| |
Collapse
|
24
|
Baskan O, Erol C, Ozbek H, Paksoy Y. Effect of radiation dose reduction on image quality in adult head CT with noise-suppressing reconstruction system with a 256 slice MDCT. J Appl Clin Med Phys 2015; 16:5360. [PMID: 26103494 PMCID: PMC5690139 DOI: 10.1120/jacmp.v16i3.5360] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 01/23/2015] [Accepted: 01/21/2015] [Indexed: 11/23/2022] Open
Abstract
The purpose of our study was to investigate the effect of iterative reconstruction (IR) as a dose reduction system on the image quality (IQ) of the adult head computed tomography (CT) at various low‐dose levels, and to identify ways of setting the amount of dose reduction. We performed two noncontrast low‐dose (LD) adult head CT protocols modified by lowering the tube current with IR which were decided in the light of a group of phantom studies. Two groups of patients, each 100 underwent noncontrast head CT with LD‐I and LD‐II, respectively. These groups were compared with 100 consecutive standard dose (STD) adult head CT protocol in terms of quantitative and qualitative IQ. The signal‐to‐noise ratio (SNR) of the white matter (WM) and gray matter (GM) and contrast‐to‐noise ratio (CNR) values in the LD groups were higher than the STD group. The differences were statistically significant. When the STD and the LD groups were compared qualitatively, no significant differences were found in overall quality. By selecting the appropriate level of IR 34%, radiation dose reduction in adult head CT can be achieved without compromising IQ. PACS number: 87.57.‐s
Collapse
|
25
|
Abstract
Traumatic ocular injuries are a significant cause of blindness and visual deficits. In the setting of acute orbital trauma, urgent ophthalmologic evaluation and intervention are critical in preserving vision. However, in the acute trauma setting, clinical evaluation of the globe may be difficult in the presence of surrounding periorbital soft-tissue swelling and other associated injuries, and patient cooperation may be limited because of unresponsiveness, altered mentation, or sedation. Often, rapid access to imaging is part of the initial diagnostic evaluation, and radiologists may be the first to identify traumatic injuries of the globe. Because of this, radiologists should be familiar with normal orbital and globe anatomy at various imaging modalities and have a thorough understanding of the various patterns of ocular injury and their imaging appearances. Radiologists should also be familiar with the various mimics of ocular injury, including congenital and acquired conditions that may alter the shape of the globe, various types of ocular calcifications, and the different types of material used to treat retinal detachment. Such knowledge may help radiologists make accurate diagnoses, which facilitates prompt and appropriate patient care.
Collapse
Affiliation(s)
- Edward K Sung
- From the Departments of Radiology (E.K.S., R.N.N., A.F., C.S., O.S.), Ophthalmology (R.H.G., A.T.), and Otolaryngology-Head and Neck Surgery (O.S.), Boston Medical Center, Boston University School of Medicine, 820 Harrison Ave, FGH Building, 3rd Floor, Boston, MA 02118; and the Department of Radiology (A.F.), Jichi Medical University School of Medicine, Shimotsuke, Tochigi, Japan
| | | | | | | | | | | | | |
Collapse
|
26
|
Donahue J, Wintermark M. Perfusion CT and acute stroke imaging: Foundations, applications, and literature review. J Neuroradiol 2015; 42:21-9. [DOI: 10.1016/j.neurad.2014.11.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 11/11/2014] [Indexed: 11/21/2022]
|
27
|
Saba L, Anzidei M, Piga M, Ciolina F, Mannelli L, Catalano C, Suri JS, Raz E. Multi-modal CT scanning in the evaluation of cerebrovascular disease patients. Cardiovasc Diagn Ther 2014; 4:245-62. [PMID: 25009794 DOI: 10.3978/j.issn.2223-3652.2014.06.05] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 05/07/2014] [Indexed: 11/14/2022]
Abstract
Ischemic stroke currently represents one of the leading causes of severe disability and mortality in the Western World. Until now, angiography was the most used imaging technique for the detection of the extra-cranial and intracranial vessel pathology. Currently, however, non-invasive imaging tool like ultrasound (US), magnetic resonance (MR) and computed tomography (CT) have proven capable of offering a detailed analysis of the vascular system. CT in particular represents an advanced system to explore the pathology of carotid arteries and intracranial vessels and also offers tools like CT perfusion (CTP) that provides valuable information of the brain's vascular physiology by increasing the stroke diagnostic. In this review, our purpose is to discuss stroke risk prediction and detection using CT.
Collapse
Affiliation(s)
- Luca Saba
- 1 Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.), di Cagliari - Polo di Monserrato s.s. 554 Monserrato (Cagliari) 09045, Italy ; 2 Departments of Radiological Sciences, University of Rome La Sapienza, Viale Regina Elena 324, 00161 (Rome), Italy ; 3 Department of Radiology, University of Washington, Seattle, Washington, USA ; 4 Fellow AIMBE, CTO, AtheroPoint LLC, Roseville, CA, USA ; 5 Department of Biomedical Engineering, Idaho State University (Aff.), ID, USA ; 6 Department of Radiology, New York University School of Medicine, New York, USA ; 7 Department of Neurology and Psychiatry, Sapienza University of Rome, Viale dell' Università, 30, 00185 Rome, Italy
| | - Michele Anzidei
- 1 Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.), di Cagliari - Polo di Monserrato s.s. 554 Monserrato (Cagliari) 09045, Italy ; 2 Departments of Radiological Sciences, University of Rome La Sapienza, Viale Regina Elena 324, 00161 (Rome), Italy ; 3 Department of Radiology, University of Washington, Seattle, Washington, USA ; 4 Fellow AIMBE, CTO, AtheroPoint LLC, Roseville, CA, USA ; 5 Department of Biomedical Engineering, Idaho State University (Aff.), ID, USA ; 6 Department of Radiology, New York University School of Medicine, New York, USA ; 7 Department of Neurology and Psychiatry, Sapienza University of Rome, Viale dell' Università, 30, 00185 Rome, Italy
| | - Mario Piga
- 1 Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.), di Cagliari - Polo di Monserrato s.s. 554 Monserrato (Cagliari) 09045, Italy ; 2 Departments of Radiological Sciences, University of Rome La Sapienza, Viale Regina Elena 324, 00161 (Rome), Italy ; 3 Department of Radiology, University of Washington, Seattle, Washington, USA ; 4 Fellow AIMBE, CTO, AtheroPoint LLC, Roseville, CA, USA ; 5 Department of Biomedical Engineering, Idaho State University (Aff.), ID, USA ; 6 Department of Radiology, New York University School of Medicine, New York, USA ; 7 Department of Neurology and Psychiatry, Sapienza University of Rome, Viale dell' Università, 30, 00185 Rome, Italy
| | - Federica Ciolina
- 1 Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.), di Cagliari - Polo di Monserrato s.s. 554 Monserrato (Cagliari) 09045, Italy ; 2 Departments of Radiological Sciences, University of Rome La Sapienza, Viale Regina Elena 324, 00161 (Rome), Italy ; 3 Department of Radiology, University of Washington, Seattle, Washington, USA ; 4 Fellow AIMBE, CTO, AtheroPoint LLC, Roseville, CA, USA ; 5 Department of Biomedical Engineering, Idaho State University (Aff.), ID, USA ; 6 Department of Radiology, New York University School of Medicine, New York, USA ; 7 Department of Neurology and Psychiatry, Sapienza University of Rome, Viale dell' Università, 30, 00185 Rome, Italy
| | - Lorenzo Mannelli
- 1 Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.), di Cagliari - Polo di Monserrato s.s. 554 Monserrato (Cagliari) 09045, Italy ; 2 Departments of Radiological Sciences, University of Rome La Sapienza, Viale Regina Elena 324, 00161 (Rome), Italy ; 3 Department of Radiology, University of Washington, Seattle, Washington, USA ; 4 Fellow AIMBE, CTO, AtheroPoint LLC, Roseville, CA, USA ; 5 Department of Biomedical Engineering, Idaho State University (Aff.), ID, USA ; 6 Department of Radiology, New York University School of Medicine, New York, USA ; 7 Department of Neurology and Psychiatry, Sapienza University of Rome, Viale dell' Università, 30, 00185 Rome, Italy
| | - Carlo Catalano
- 1 Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.), di Cagliari - Polo di Monserrato s.s. 554 Monserrato (Cagliari) 09045, Italy ; 2 Departments of Radiological Sciences, University of Rome La Sapienza, Viale Regina Elena 324, 00161 (Rome), Italy ; 3 Department of Radiology, University of Washington, Seattle, Washington, USA ; 4 Fellow AIMBE, CTO, AtheroPoint LLC, Roseville, CA, USA ; 5 Department of Biomedical Engineering, Idaho State University (Aff.), ID, USA ; 6 Department of Radiology, New York University School of Medicine, New York, USA ; 7 Department of Neurology and Psychiatry, Sapienza University of Rome, Viale dell' Università, 30, 00185 Rome, Italy
| | - Jasjit S Suri
- 1 Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.), di Cagliari - Polo di Monserrato s.s. 554 Monserrato (Cagliari) 09045, Italy ; 2 Departments of Radiological Sciences, University of Rome La Sapienza, Viale Regina Elena 324, 00161 (Rome), Italy ; 3 Department of Radiology, University of Washington, Seattle, Washington, USA ; 4 Fellow AIMBE, CTO, AtheroPoint LLC, Roseville, CA, USA ; 5 Department of Biomedical Engineering, Idaho State University (Aff.), ID, USA ; 6 Department of Radiology, New York University School of Medicine, New York, USA ; 7 Department of Neurology and Psychiatry, Sapienza University of Rome, Viale dell' Università, 30, 00185 Rome, Italy
| | - Eytan Raz
- 1 Department of Radiology, Azienda Ospedaliero Universitaria (A.O.U.), di Cagliari - Polo di Monserrato s.s. 554 Monserrato (Cagliari) 09045, Italy ; 2 Departments of Radiological Sciences, University of Rome La Sapienza, Viale Regina Elena 324, 00161 (Rome), Italy ; 3 Department of Radiology, University of Washington, Seattle, Washington, USA ; 4 Fellow AIMBE, CTO, AtheroPoint LLC, Roseville, CA, USA ; 5 Department of Biomedical Engineering, Idaho State University (Aff.), ID, USA ; 6 Department of Radiology, New York University School of Medicine, New York, USA ; 7 Department of Neurology and Psychiatry, Sapienza University of Rome, Viale dell' Università, 30, 00185 Rome, Italy
| |
Collapse
|
28
|
Ryska P, Kvasnicka T, Jandura J, Klzo L, Grepl J, Zizka J. Reduction of effective dose and organ dose to the eye lens in head MDCT using iterative image reconstruction and automatic tube current modulation. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2014; 158:265-72. [DOI: 10.5507/bp.2013.071] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 09/16/2013] [Indexed: 11/23/2022] Open
|
29
|
Chu WF, Lin CJ, Chen WS, Hung SC, Chiu CF, Wu TH, Guo WY. Radiation doses of cerebral blood volume measurements using C-arm CT: A phantom study. AJNR Am J Neuroradiol 2014; 35:1073-7. [PMID: 24371024 PMCID: PMC7965136 DOI: 10.3174/ajnr.a3822] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 10/12/2013] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND PURPOSE Parenchymal blood volume measurement by C-arm CT facilitates in-room peritherapeutic perfusion evaluation. However, the radiation dose remains a major concern. This study aimed to compare the radiation dose of parenchymal blood volume measurement using C-arm CT with that of conventional CTP using multidetector CT. MATERIALS AND METHODS A biplane DSA equipped with C-arm CT and a Rando-Alderson phantom were used. Slab parenchymal blood volume (8-cm scanning range in a craniocaudal direction) and whole-brain parenchymal blood volume with identical scanning parameters, except for scanning ranges, were undertaken on DSA. Eighty thermoluminescent dosimeters were embedded into 22 organ sites of the phantom. We followed the guidelines of the International Commission on Radiation Protection number 103 to calculate the effective doses. For comparison, 8-cm CTP with the same phantom and thermoluminescent dosimeter distribution was performed on a multidetector CT. Two repeat dose experiments with the same scanning parameters and phantom and thermoluminescent dosimeter settings were conducted. RESULTS Brain-equivalent dose in slab parenchymal blood volume, whole-brain parenchymal blood volume, and CTP were 52.29 ± 35.31, 107.51 ± 31.20, and 163.55 ± 89.45 mSv, respectively. Variations in the measurement of an equivalent dose for the lens were highest in slab parenchymal blood volume (64.5%), followed by CTP (54.6%) and whole-brain parenchymal blood volume (29.0%). The effective doses of slab parenchymal blood volume, whole-brain parenchymal blood volume, and CTP were 0.87 ± 0.55, 3.91 ± 0.78, and 2.77 ± 1.59 mSv, respectively. CONCLUSIONS The dose measurement conducted in the current study was reliable and reproducible. The effective dose of slab parenchymal blood volume is about one-third that of CTP. With the advantages of on-site and immediate imaging availability and saving procedural time and patient transportation, slab parenchymal blood volume measurement using C-arm CT can be recommended for clinical application.
Collapse
Affiliation(s)
- W F Chu
- From the Department of Radiology (W.F.C., C.J.L., S.C.H., C.F.C., W.Y.G.), Taipei Veterans General Hospital, Taipei, TaiwanSchool of Medicine (W.F.C., C.J.L., S.C.H., C.F.C., W.Y.G.)
| | - C J Lin
- From the Department of Radiology (W.F.C., C.J.L., S.C.H., C.F.C., W.Y.G.), Taipei Veterans General Hospital, Taipei, TaiwanSchool of Medicine (W.F.C., C.J.L., S.C.H., C.F.C., W.Y.G.)
| | - W S Chen
- Department of Biomedical Imaging and Radiological Sciences (W.S.C., T.H.W.), National Yang-Ming University, Taipei, Taiwan
| | - S C Hung
- From the Department of Radiology (W.F.C., C.J.L., S.C.H., C.F.C., W.Y.G.), Taipei Veterans General Hospital, Taipei, TaiwanSchool of Medicine (W.F.C., C.J.L., S.C.H., C.F.C., W.Y.G.)
| | - C F Chiu
- From the Department of Radiology (W.F.C., C.J.L., S.C.H., C.F.C., W.Y.G.), Taipei Veterans General Hospital, Taipei, TaiwanSchool of Medicine (W.F.C., C.J.L., S.C.H., C.F.C., W.Y.G.)
| | - T H Wu
- Department of Biomedical Imaging and Radiological Sciences (W.S.C., T.H.W.), National Yang-Ming University, Taipei, Taiwan.
| | - W Y Guo
- From the Department of Radiology (W.F.C., C.J.L., S.C.H., C.F.C., W.Y.G.), Taipei Veterans General Hospital, Taipei, TaiwanSchool of Medicine (W.F.C., C.J.L., S.C.H., C.F.C., W.Y.G.)
| |
Collapse
|
30
|
Zhou Y, Chen MN, Liu Y. Use of low-dose contrast agent in cerebral angiography produces high-quality diagnostic images. Int J Clin Exp Med 2014; 7:1331-1335. [PMID: 24995091 PMCID: PMC4073752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 05/16/2014] [Indexed: 06/03/2023]
Abstract
The present study was aimed to study feasibility of low-dose contrast agent in cerebral CT angiography (CTA) to alleviate some side effects and costs associated with routine doses of contrast agent. Sixty patients suspected to have cerebral artery disease were randomly selected to receive either low-dose (60 mL) contrast agent or routine-dose (100 mL) contrast agent. CTA included transverse images, volume rendering (VR), and maximum intensity projection (MIP) images. Developing strength, image noise, and structure display effects of the cerebral artery were compared between groups. The developing strength and image noise of the cerebral artery were equivalent between groups (P > 0.05). No statistical differences were observed in structure display effects of the cerebral artery or in radiological diagnosis between groups (P > 0.05). Application of the low-dose contrast agent is feasible and offers comparable diagnostic capabilities in cerebral CT angiography.
Collapse
Affiliation(s)
- Yang Zhou
- Department of Radiology, Harbin Medical University Cancer HospitalHarbin 150081, Heilongjiang Province, China
| | - Mu-Nan Chen
- Department of PET-CT/MR, Harbin Medical University Cancer HospitalHarbin 150081, Heilongjiang Province, China
| | - Yang Liu
- Department of Radiology, Harbin Medical University Cancer HospitalHarbin 150081, Heilongjiang Province, China
| |
Collapse
|
31
|
Luo S, Zhang LJ, Meinel FG, Zhou CS, Qi L, McQuiston AD, Schoepf UJ, Lu GM. Low tube voltage and low contrast material volume cerebral CT angiography. Eur Radiol 2014; 24:1677-85. [PMID: 24792591 DOI: 10.1007/s00330-014-3184-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 03/13/2014] [Accepted: 04/09/2014] [Indexed: 12/01/2022]
Abstract
OBJECTIVES To evaluate the image quality, radiation dose and diagnostic accuracy of low kVp and low contrast material volume cerebral CT angiography (CTA) in intracranial aneurysm detection. METHODS One hundred twenty patients were randomly divided into three groups (n = 40 for each): Group A, 70 ml iodinated contrast agent/120 kVp; group B, 30 ml/100 kVp; group C, 30 ml/80 kVp. The CT numbers, noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured in the internal carotid artery (ICA) and middle cerebral artery (MCA). Subjective image quality was evaluated. For patients undergoing DSA, diagnostic accuracy of CTA was calculated with DSA as reference standard and compared. RESULTS CT numbers of ICA and MCA were higher in groups B and C than in group A (P < 0.01). SNR and CNR in groups A and B were higher than in group C (both P < 0.05). There was no difference in subjective image quality among the three groups (P = 0.939). Diagnostic accuracy for aneurysm detection among these groups had no statistical difference (P = 1.00). Compared with group A, the radiation dose of groups B and C was decreased by 45% and 74%. CONCLUSION Cerebral CTA at 100 or 80 kVp using 30 ml contrast agent can obtain diagnostic image quality with a low radiation dose while maintaining the same diagnostic accuracy for aneurysm detection. KEY POINTS • Cerebral CTA is feasible using 100/80 kVp and 30 ml contrast agent. • This approach obtains diagnostic image quality with 45-74% radiation dose reduction. • Diagnostic accuracy for intracranial aneurysm detection seems not to be compromised.
Collapse
Affiliation(s)
- Song Luo
- Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, 210002, China
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Bodelle B, Klein E, Naguib NNN, Bauer RW, Kerl JM, Al-Butmeh F, Wichmann JL, Ackermann H, Lehnert T, Vogl TJ, Schulz B. Acute intracranial hemorrhage in CT: benefits of sinogram-affirmed iterative reconstruction techniques. AJNR Am J Neuroradiol 2014; 35:445-9. [PMID: 24263695 DOI: 10.3174/ajnr.a3801] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Acute intracranial hemorrhage represents a severe and time critical pathology that requires precise and quick diagnosis, mainly by performing a CT scan. The purpose of this study was to compare image quality and intracranial hemorrhage conspicuity in brain CT with sinogram-affirmed iterative reconstruction and filtered back-projection reconstruction techniques at standard (340 mAs) and low-dose tube current levels (260 mAs). MATERIALS AND METHODS A total of 94 consecutive patients with intracranial hemorrhage received CT scans either with standard or low-dose protocol by random assignment. Group 1 (n=54; mean age, 64 ± 20 years) received CT at 340 mAs, and group 2 (n=40; mean age, 57 ± 23 years) received CT at 260 mAs. Images of both groups were reconstructed with filtered back-projection reconstruction and 5 iterative strengths (S1-S5) and ranked blind by 2 radiologists for image quality and intracranial hemorrhage on a 5-point scale. Image noise, SNR, dose-length product (mGycm), and mean effective dose (mSv) were calculated. RESULTS In both groups, image quality and intracranial hemorrhage conspicuity were rated subjectively with an excellent/good image quality. A higher strength of sinogram-affirmed iterative reconstruction showed an increase in image quality with a difference to filtered back-projection reconstruction (P < .05). Subjective rating showed the best score of image quality and intracranial hemorrhage conspicuity achieved through S3/S4-5. Objective analysis of image quality showed in an increase of SNR with a higher strength of sinogram-affirmed iterative reconstruction. Patients in group 2 (mean: 744 mGycm/1.71 mSv) were exposed to a significantly lower dose than those in group 1 (mean: 1045 mGycm/2.40 mSv, P < .01). CONCLUSIONS S3 provides better image quality and visualization of intracranial hemorrhage in brain CT at 260 mAs. Dose reduction by almost one-third is possible without significant loss in diagnostic quality.
Collapse
Affiliation(s)
- B Bodelle
- From the Departments of Diagnostic and Interventional Radiology (B.B., E.K., N.N.N.N., R.W.B., J.M.K., F.A.-B., J.L.W., T.L., T.J.V., B.S.)
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Liu Y, Ma J, Zhang H, Wang J, Liang Z. Low-mAs X-ray CT image reconstruction by adaptive-weighted TV-constrained penalized re-weighted least-squares. J Xray Sci Technol 2014; 22:437-457. [PMID: 25080113 PMCID: PMC4141624 DOI: 10.3233/xst-140437] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
BACKGROUND The negative effects of X-ray exposure, such as inducing genetic and cancerous diseases, has arisen more attentions. OBJECTIVE This paper aims to investigate a penalized re-weighted least-square (PRWLS) strategy for low-mAs X-ray computed tomography image reconstruction by incorporating an adaptive weighted total variation (AwTV) penalty term and a noise variance model of projection data. METHODS An AwTV penalty is introduced in the objective function by considering both piecewise constant property and local nearby intensity similarity of the desired image. Furthermore, the weight of data fidelity term in the objective function is determined by our recent study on modeling variance estimation of projection data in the presence of electronic background noise. RESULTS The presented AwTV-PRWLS algorithm can achieve the highest full-width-at-half-maximum (FWHM) measurement, for data conditions of (1) full-view 10 mA acquisition and (2) sparse-view 80 mA acquisition. In comparison between the AwTV/TV-PRWLS strategies and the previous reported AwTV/TV-projection onto convex sets (AwTV/TV-POCS) approaches, the former can gain in terms of FWHM for data condition (1), but cannot gain for the data condition (2). CONCLUSIONS In the case of full-view 10 mA projection data, the presented AwTV-PRWLS shows potential improvement. However, in the case of sparse-view 80 mA projection data, the AwTV/TV-POCS shows advantage over the PRWLS strategies.
Collapse
Affiliation(s)
- Yan Liu
- Department of Radiology, State University of New York, Stony Brook,
NY 11794, USA
- Department of Electrical and Computer Engineering, State University
of New York, Stony Brook, NY 11794, USA
| | - Jianhua Ma
- School of Biomedical Engineering, Southern Medical University,
Guangzhou 510515, China
| | - Hao Zhang
- Department of Radiology, State University of New York, Stony Brook,
NY 11794, USA
- Department of Biomedical Engineering, State University of New York,
Stony Brook, NY 11794, USA
| | - Jing Wang
- Department of Radiation Oncology, University of Texas Southwestern
Medical Center, TX 75390, USA
| | - Zhengrong Liang
- Department of Radiology, State University of New York, Stony Brook,
NY 11794, USA
- Department of Biomedical Engineering, State University of New York,
Stony Brook, NY 11794, USA
| |
Collapse
|
34
|
Huang J, Zhang Y, Ma J, Zeng D, Bian Z, Niu S, Feng Q, Liang Z, Chen W. Iterative image reconstruction for sparse-view CT using normal-dose image induced total variation prior. PLoS One 2013; 8:e79709. [PMID: 24260288 PMCID: PMC3832537 DOI: 10.1371/journal.pone.0079709] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 09/24/2013] [Indexed: 11/19/2022] Open
Abstract
X-ray computed tomography (CT) iterative image reconstruction from sparse-view projection data has been an important research topic for radiation reduction in clinic. In this paper, to relieve the requirement of misalignment reduction operation of the prior image constrained compressed sensing (PICCS) approach introduced by Chen et al, we present an iterative image reconstruction approach for sparse-view CT using a normal-dose image induced total variation (ndiTV) prior. The associative objective function of the present approach is constructed under the penalized weighed least-square (PWLS) criteria, which contains two terms, i.e., the weighted least-square (WLS) fidelity and the ndiTV prior, and is referred to as "PWLS-ndiTV". Specifically, the WLS fidelity term is built based on an accurate relationship between the variance and mean of projection data in the presence of electronic background noise. The ndiTV prior term is designed to reduce the influence of the misalignment between the desired- and prior- image by using a normal-dose image induced non-local means (ndiNLM) filter. Subsequently, a modified steepest descent algorithm is adopted to minimize the associative objective function. Experimental results on two different digital phantoms and an anthropomorphic torso phantom show that the present PWLS-ndiTV approach for sparse-view CT image reconstruction can achieve noticeable gains over the existing similar approaches in terms of noise reduction, resolution-noise tradeoff, and low-contrast object detection.
Collapse
Affiliation(s)
- Jing Huang
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Yunwan Zhang
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Jianhua Ma
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Dong Zeng
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Zhaoying Bian
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Shanzhou Niu
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Qianjin Feng
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Zhengrong Liang
- Department of Radiology, State University of New York, Stony Brook, New York, United States of America
| | - Wufan Chen
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| |
Collapse
|
35
|
Lin CJ, Wu TH, Lin CH, Hung SC, Chiu CF, Liu MJ, Teng MMH, Chang FC, Guo WY, Chang CY. Can iterative reconstruction improve imaging quality for lower radiation CT perfusion? Initial experience. AJNR Am J Neuroradiol 2013; 34:1516-21. [PMID: 23578678 DOI: 10.3174/ajnr.a3436] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Initial results using IR for CT of the head showed satisfactory subjective and objective imaging quality with a 20-40% radiation dose reduction. The aim of our study was to compare the influence of IR and FBP algorithms on perfusion parameters at standard and lowered doses of CTP. MATERIALS AND METHODS Forty patients with unilateral carotid stenosis post-carotid stent placement referred for follow-up CTP were divided into 2 groups (tube currents were 100 mAs in group A and 80 mAs in group B). Datasets were reconstructed with IR and FBP algorithms; and SNRs of gray matter, white matter, and arterial and venous ROIs were compared. CBF, CBV, and MTT means and SNRs were evaluated by using linear regression, and qualitative imaging scores were compared across the 2 algorithms. RESULTS The mean effective radiation dose of group B (2.06 mSv) was approximately 20% lower than that of group A (2.56 mSv). SNRs for ROIs in the dynamic contrast-enhanced images were significantly higher than those for the FBP images. Correlations of the SNRs for CBF, CBV, and MTT across the 2 algorithms were moderate (R² = 0.46, 0.23, and 0.44, respectively). ROIs in gray matter rather than the IR algorithm predicted increasing SNRs in all CBF, CBV, and MTT maps. Two cases of significant restenosis were confirmed in both algorithms. CBV, CBF, and MTT imaging scores did not differ significantly across algorithms or groups. CONCLUSIONS Lower dose CTP (20% below normal dose) without IR can effectively identify oligemic tissue in poststenting follow-up. IR does not alter the absolute values or increase the SNRs of perfusion parameters. Other methods should be attempted to improve SNRs in settings with low tube currents.
Collapse
Affiliation(s)
- C J Lin
- Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Juluru K, Shih JC, Raj A, Comunale JP, Delaney H, Greenberg ED, Hermann C, Liu YB, Hoelscher A, Al-Khori N, Sanelli PC. Effects of increased image noise on image quality and quantitative interpretation in brain CT perfusion. AJNR Am J Neuroradiol 2013; 34:1506-12. [PMID: 23557960 DOI: 10.3174/ajnr.a3448] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE There is a desire within many institutions to reduce the radiation dose in CTP examinations. The purpose of this study was to simulate dose reduction through the addition of noise in brain CT perfusion examinations and to determine the subsequent effects on quality and quantitative interpretation. MATERIALS AND METHODS A total of 22 consecutive reference CTP scans were identified from an institutional review board-approved prospective clinical trial, all performed at 80 keV and 190 mAs. Lower-dose scans at 188, 177, 167, 127, and 44 mAs were generated through the addition of spatially correlated noise to the reference scans. A standard software package was used to generate CBF, CBV, and MTT maps. Six blinded radiologists determined quality scores of simulated scans on a Likert scale. Quantitative differences were calculated. RESULTS For qualitative analysis, the correlation coefficients for CBF (-0.34; P < .0001), CBV (-0.35; P < .0001), and MTT (-0.44; P < .0001) were statistically significant. Interobserver agreements in quality for the simulated 188-, 177-, 167-, 127-, and 44-mAs scans for CBF were 0.95, 0.98, 0.98, 0.95, and 0.52, respectively. Interobserver agreements in quality for the simulated CBV were 1, 1, 1, 1, and 0.83, respectively. For MTT, the interobserver agreements were 0.83, 0.86, 0.88, 0.74, and 0.05, respectively. For quantitative analysis, only the lowest simulated dose of 44 mAs showed statistically significant differences from the reference scan values for CBF (-1.8; P = .04), CBV (0.07; P < .0001), and MTT (0.46; P < .0001). CONCLUSIONS From a reference CTP study performed at 80 keV and 190 mAs, this simulation study demonstrates the potential of a 33% reduction in tube current and dose while maintaining image quality and quantitative interpretations. This work can be used to inform future studies by using true, nonsimulated scans.
Collapse
Affiliation(s)
- K Juluru
- Department of Radiology, Weill Cornell Medical College, New York-Presbyterian Hospital, New York, NY 10065, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Siegelman JRQW, Gress DA. Radiology stewardship and quality improvement: the process and costs of implementing a CT radiation dose optimization committee in a medium-sized community hospital system. J Am Coll Radiol 2013; 10:416-22. [PMID: 23491153 DOI: 10.1016/j.jacr.2012.12.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 12/05/2012] [Indexed: 12/20/2022]
Abstract
PURPOSE The aims of this study were to measure the effectiveness of a multidisciplinary CT dose optimization committee and estimate its costs and to describe a radiation stewardship quality improvement initiative in one CT department at a medium-sized community hospital system that used a participatory design committee methodology. METHODS A CT dose optimization committee was conceived, funded, and formed, consisting of the following stakeholders: radiologists, technologists, consultant medical physicists, and an administrator. Volume CT dose index (CTDIvol) and repeat rate were monitored for 1 month, for one scan type, during which iterative protocol adjustments were made through committee interaction. Effects on repeat rate and CTDIvol were quantified and benchmarked against national diagnostic reference levels after retrospective medical record review of 100 consecutive patients before and after the intervention. Labor hours were reported and wage resources estimated. RESULTS Over 3 months, the committee met in person twice and exchanged 128 e-mails in establishing a process for protocol improvement and measurement of success. Repeat rate was reduced from 13% (13 of 100) to 0% (0 of 100). Scans meeting the ACR reference level for CTDIvol (75 mGy) improved by 34% (38 of 100 before, 51 of 100 after; Fisher's exact 2-tailed P = .09), and those meeting ACR pass/fail criterion (80 mGy) improved by 29% (58 of 100 before, 75 of 100 after; Fisher's exact 2-tailed P = .01). Committee evolution and work, and protocol development and implementation, required 57 person-hours, at an estimated labor cost of $12,488. CONCLUSIONS An efficient process was established as a proof of concept for the use of a multidisciplinary committee to reduce patient radiation dose, repeat rate, and variability in image quality. The committee and process ultimately improved the quality of patient care, fostered a culture of safety and ongoing quality improvement, and calculated costs for such an endeavor.
Collapse
Affiliation(s)
- Jenifer R Q W Siegelman
- Norwich Diagnostic Imaging at The William W. Backus Hospital, Norwich, Connecticut 06360, USA.
| | | |
Collapse
|
38
|
Fwu CW, Eggers PW, Kimmel PL, Kusek JW, Kirkali Z. Emergency department visits, use of imaging, and drugs for urolithiasis have increased in the United States. Kidney Int. 2013;83:479-486. [PMID: 23283137 PMCID: PMC3587650 DOI: 10.1038/ki.2012.419] [Citation(s) in RCA: 148] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The occurrence of urolithiasis in the United States has increased; however, information on long-term trends, including recurrence rates, is lacking. Here we describe national trends in rates of emergency department visits, use of imaging, and drug treatment, primarily using the National Hospital Ambulatory Medical Care Survey to describe trends and the National Health and Nutrition Examination Survey to determine the frequency of lifetime passage of kidney stones. Emergency department visit rates for urolithiasis increased from 178 to 340 visits per 100,000 individuals from 1992 to 2009. Increases in visit rates were greater in women, Caucasians, and in those aged 25–44 years. The use of computed tomography in urolithiasis patients more than tripled, from 21 to 71%. Medical expulsive therapy was used in 14% of the patients with a urolithiasis diagnosis in 2007–2009. Among National Health and Nutrition Examination Survey participants who reported a history of kidney stones, 22.4% had passed three or more stones. Hence, emergency department urolithiasis visit rates have increased significantly, as has the use of computed tomography in the United States. Further research is necessary to determine whether recurrent stone formers receive unnecessary radiation exposure during diagnostic evaluation in the emergency department and allow development of corresponding evidence-based guidelines.
Collapse
|
39
|
Vorona GA, Zuccoli G, Sutcavage T, Clayton BL, Ceschin RC, Panigrahy A. The use of adaptive statistical iterative reconstruction in pediatric head CT: a feasibility study. AJNR Am J Neuroradiol 2012; 34:205-11. [PMID: 22627796 DOI: 10.3174/ajnr.a3122] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Iterative reconstruction techniques facilitate CT dose reduction; though to our knowledge, no group has explored using iterative reconstruction with pediatric head CT. Our purpose was to perform a feasibility study to assess the use of ASIR in a small group of pediatric patients undergoing head CT. MATERIALS AND METHODS An Alderson-Rando head phantom was scanned at decreasing 10% mA intervals relative to our standard protocol, and each study was then reconstructed at 10% ASIR intervals. An intracranial region of interest was consistently placed to estimate noise. Our ventriculoperitoneal shunt CT protocol was subsequently modified, and patients were scanned at 20% ASIR with approximately 20% mA reductions. ASIR studies were anonymously compared with older non-ASIR studies from the same patients by 2 attending pediatric neuroradiologists for diagnostic utility, sharpness, noise, and artifacts. RESULTS The phantom study demonstrated similar noise at 100% mA/0% ASIR (3.9) and 80% mA/20% ASIR (3.7). Twelve pediatric patients were scanned at reduced dose at 20% ASIR. The average CTDI(vol) and DLP values of the 20% ASIR studies were 22.4 mGy and 338.4 mGy-cm, and for the non-ASIR studies, they were 28.8 mGy and 444.5 mGy-cm, representing statistically significant decreases in the CTDI(vol) (22.1%, P = .00007) and DLP (23.9%, P = .0005) values. There were no significant differences between the ASIR studies and non-ASIR studies with respect to diagnostic acceptability, sharpness, noise, or artifacts. CONCLUSIONS Our findings suggest that 20% ASIR can provide approximately 22% dose reduction in pediatric head CT without affecting image quality.
Collapse
Affiliation(s)
- G A Vorona
- Department of Radiology, Allegheny General Hospital, Pittsburgh, Pennsylvania, USA
| | | | | | | | | | | |
Collapse
|
40
|
Cho ES, Chung TS, Oh DK, Choi HS, Suh SH, Lee HK, Lee KH. Cerebral computed tomography angiography using a low tube voltage (80 kVp) and a moderate concentration of iodine contrast material: a quantitative and qualitative comparison with conventional computed tomography angiography. Invest Radiol 2012; 47:142-7. [PMID: 22104960 DOI: 10.1097/RLI.0b013e31823076a4] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
OBJECTIVE To investigate the feasibility of an 80-kVp protocol using a moderate concentration contrast material (MC-CM) for cerebral computed tomography angiography by comparison with a conventional 120-kVp protocol using a high concentration contrast material (HC-CM). MATERIALS AND METHODS Attenuation values and signal-to-noise ratios (SNRs) were determined in a head phantom for 2 tube voltages (80 and 120 kVp) and 2 different iodine concentration contrast materials (HC-CM and MC-CM). Among 90 consecutive patients, 45 patients were scanned with 120 kVp and 150 mAs(eff) after administration of 70 mL of HC-CM (370 mg iodine [mgI]/mL), whereas the other 45 patients were scanned with 80 kVp and 370 mAs(eff) after administration of 70 mL of MC-CM (300 mgI/mL). The Hounsfield units (HU) of the internal carotid artery T junction, SNR, contrast-to-noise ratio (CNR), subjective degree of arterial enhancement, image noise, sharpness of the cerebral arterial boundary, and overall diagnostic image quality were compared between the 2 groups. RESULTS The mean attenuation of the internal carotid artery T junction, SNR, and CNR was significantly higher in the 80 kVp with MC-CM group (379.2, 33.7, and 31.1 HU, respectively) than in the 120 kVp with HC-CM group (282.2, 31.1, and 27.2 HU, respectively). The 80-kVp protocol resulted in significantly higher score in arterial enhancement, sharpness of the cerebral arteries, and overall diagnostic image quality. The effective dose of 80 kVp (0.7 mSv) was 22.2% lower than that of 120 kVp (0.9 mSv). CONCLUSIONS The use of 80 kVp with MC-CM improved arterial enhancement, SNR, and CNR and provided superior quality images using a smaller amount of iodine and a lower radiation dose than the conventional protocol of 120 kVp with HC-CM.
Collapse
|
41
|
Nickerson JP, Richner B, Santy K, Lequin MH, Poretti A, Filippi CG, Huisman TA. Neuroimaging of Pediatric Intracranial Infection-Part 1: Techniques and Bacterial Infections. J Neuroimaging 2012; 22:e42-51. [DOI: 10.1111/j.1552-6569.2011.00700.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
42
|
Calisir C, Fayad LM, Carrino JA, Fishman EK. Recognition, assessment, and treatment of non-union after surgical fixation of fractures: emphasis on 3D CT. Jpn J Radiol 2012; 30:1-9. [DOI: 10.1007/s11604-011-0006-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 07/31/2011] [Indexed: 02/07/2023]
|
43
|
Noël PB, Fingerle AA, Renger B, Münzel D, Rummeny EJ, Dobritz M. Initial Performance Characterization of a Clinical Noise–Suppressing Reconstruction Algorithm for MDCT. AJR Am J Roentgenol 2011; 197:1404-9. [PMID: 22109296 DOI: 10.2214/ajr.11.6907] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
44
|
Lee S, Yoon SW, Yoo SM, Ji YG, Kim KA, Kim SH, Lee JT. Comparison of image quality and radiation dose between combined automatic tube current modulation and fixed tube current technique in CT of abdomen and pelvis. Acta Radiol 2011; 52:1101-6. [PMID: 21903869 DOI: 10.1258/ar.2011.100295] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Tube current is an important determinant of radiation dose and image quality in X-ray-based examination. The combined automatic tube current modulation technique (ATCM) enables automatic adjustment of the tube current in various planes (x-y and z) based on the size and attenuation of the body area scanned. PURPOSE To compare image quality and radiation dose of the ATCM with those of a fixed tube current technique (FTC) in CT of the abdomen and pelvis performed with a 16-slice multidetector row CT. MATERIAL AND METHODS We reviewed 100 patients in whom initial and follow-up CT of the abdomen and pelvis were performed with FTC and ATCM. All acquisition parameters were identical in both techniques except for tube current. We recorded objective image noise in liver parenchyma, subjective image noise and diagnostic acceptability by using a five-point scale, radiation dose, and body mass index (BMI, kg/m(2)). Data were analyzed with parametric and non-parametric statistical tests. RESULTS There was no significant difference in image noise and diagnostic acceptability between two techniques. All subjects had acceptable subjective image noise in both techniques. The significant reduction in radiation dose (45.25% reduction) was noted with combined ATCM (P < 0.001). There was a significant linear statistical correlation between BMI and dose reduction (r = -0.78, P < 0.05). CONCLUSION The ATCM for CT of the abdomen and pelvis substantially reduced radiation dose while maintaining diagnostic image quality. Patients with lower BMI showed more reduction in radiation dose.
Collapse
Affiliation(s)
- Sanghee Lee
- Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine
| | - Sang-Wook Yoon
- Department of Diagnostic Radiology, CHA Bundang Medical Center, CHA University
| | - Seung-Min Yoo
- Department of Diagnostic Radiology, CHA Bundang Medical Center, CHA University
| | - Young Geon Ji
- Preventive Medicine, CHA Bundang Medical Center, CHA University, Korea
| | - Kyoung Ah Kim
- Department of Diagnostic Radiology, CHA Bundang Medical Center, CHA University
| | - Sang Heum Kim
- Department of Diagnostic Radiology, CHA Bundang Medical Center, CHA University
| | - Jong Tae Lee
- Department of Diagnostic Radiology, CHA Bundang Medical Center, CHA University
| |
Collapse
|
45
|
Kilic K, Erbas G, Guryildirim M, Arac M, Ilgit E, Coskun B. Lowering the dose in head CT using adaptive statistical iterative reconstruction. AJNR Am J Neuroradiol 2011; 32:1578-82. [PMID: 21835946 DOI: 10.3174/ajnr.a2585] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE While CT has found wide use in medical practice, it is also a substantial source of radiation exposure and is associated with an increased lifetime risk of cancer. There is an urgent need for new approaches to reduce the radiation dose in CT. In this regard, ASIR is an alternative method to FBP. We assessed the effect of ASIR on dose reduction in adult head CT. MATERIALS AND METHODS We retrospectively evaluated a sample of 149 adult head CT examinations that were divided into 2 groups, STD and LD. We lowered the tube current and used ASIR in the LD group. SNR and CNR were analyzed. Dose parameters were recorded while subjective image noise, sharpness, diagnostic acceptability, and artifacts were graded. The Student t test, the Mann-Whitney U test, and κ statistics were used for statistical analyses. RESULTS We achieved a dose reduction of 31% in the LD group (STD, 2.3 ± 0.1 mSv; LD, 1.6 ± 0.1 mSv; P < .001). There was no significant difference in the noise measured in the air between the 2 comparison groups (P = .273). Noise in the CSF was higher in the STD group (P < .001), while the noise in the WM was higher in the LD group (P < .001). Differences in the CNR between groups were insignificant, but the STD group displayed better SNR values. There was no significant difference in the modal scores of diagnostic acceptability (P = .062) and the artifacts (P = .148) between the 2 groups. Better scores for subjective image noise (P < .001) and sharpness (P = .04) were observed in the STD group. CONCLUSIONS ASIR appears to be useful in reducing the dose in adult head CT examinations. While the effect of ASIR on noise reduction observed in the present study of head CT is less than that reported previously in abdomen and chest CT, these findings encourage further prospective studies in larger patient samples.
Collapse
Affiliation(s)
- K Kilic
- Department of Radiology, School of Medicine, Gazi University, Ankara, Turkey.
| | | | | | | | | | | |
Collapse
|
46
|
Schindera ST, Treier R, von Allmen G, Nauer C, Trueb PR, Vock P, Szucs-Farkas Z. An education and training programme for radiological institutes: impact on the reduction of the CT radiation dose. Eur Radiol 2011; 21:2039-45. [DOI: 10.1007/s00330-011-2168-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Revised: 04/14/2011] [Accepted: 04/15/2011] [Indexed: 12/11/2022]
|
47
|
|
48
|
Shankar JJ, Lum C, Sharma M. Whole-brain perfusion imaging with 320-MDCT scanner: Reducing radiation dose by increasing sampling interval. AJR Am J Roentgenol 2010; 195:1183-6. [PMID: 20966326 DOI: 10.2214/AJR.10.4230] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this study was to investigate whether perfusion CT values obtained with a reduced-dose imaging protocol on a 320-MDCT scanner are similar to those obtained with a standard protocol. CONCLUSION Similar perfusion values at one-half the radiation dose can be obtained with the alternative algorithm used in this study.
Collapse
|
49
|
Jaffe TA, Hoang JK, Yoshizumi TT, Toncheva G, Lowry C, Ravin C. Radiation dose for routine clinical adult brain CT: Variability on different scanners at one institution. AJR Am J Roentgenol 2010; 195:433-8. [PMID: 20651201 DOI: 10.2214/AJR.09.3957] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this study was to determine, using an anthropomorphic phantom, whether patients are subject to variable radiation doses based on scanner assignment for routine CT of the brain. MATERIALS AND METHODS Twenty metal oxide semiconductor field effect transistor dosimeters were placed in the brain of a male anthropomorphic phantom scanned three times with a routine clinical brain CT protocol on four scanners from one manufacturer in four configurations and on one 64-MDCT scanner from another manufacturer. Absorbed organ doses were measured for skin, cranium, brain, lens of the eye, mandible, and thyroid. Effective dose was calculated on the basis of the dose-length product recorded on each scanner. RESULTS Organ dose ranges were as follows: cranium, 2.57-3.47 cGy; brain, 2.34-3.78 cGy; lens, 2.51-5.03 cGy; mandible 0.17-0.48 cGy; and thyroid, 0.03-0.28 cGy. Statistically significant differences between scanners with respect to dose were recorded for brain and lens (p < 0.05). Absorbed doses were lowest on the single-detector scanner. In the comparison of MDCT scanners, the highest doses were found on the 4-MDCT scanner and the dual-source 64-MDCT scanner not capable of gantry tilt. Effective dose ranged from 1.22 to 1.86 mSv. CONCLUSION According to the phantom data, patients are subject to different organ doses in the lens and brain depending on scanner assignment. At our institution with existing protocols, absorbed doses at brain CT are lowest with the single-detector CT scanner, followed by MDCT scanners capable of gantry tilt. On scanners without gantry tilt, CT of the brain should be performed with careful head positioning and shielding of the orbits. These precautions are especially true for patients who need repeated scanning and for pediatric patients.
Collapse
|
50
|
Johnston J, Comello RJ, Vealé BL, Killion J. Radiation Exposure Dose Trends and Radiation Dose Reduction Strategies in Medical Imaging. J Med Imaging Radiat Sci 2010; 41:137-144. [DOI: 10.1016/j.jmir.2010.06.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Revised: 05/19/2010] [Accepted: 06/10/2010] [Indexed: 10/24/2022]
|