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Three-Dimensional Printing for Construction of Tissue-Equivalent Anthropomorphic Phantoms and Determination of Conceptus Dose. AJR Am J Roentgenol 2018; 211:1283-1290. [PMID: 30354270 DOI: 10.2214/ajr.17.19489] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this study was to develop a road map for rapid construction of anthropomorphic phantoms from computational human phantoms for use in diagnostic imaging dosimetry studies. These phantoms are ideal for performing pregnant-patient dosimetry because the phantoms imitate the size and attenuation properties of an average-sized pregnant woman for multiple gestational periods. MATERIALS AND METHODS The method was derived from methods and materials previously described but adapted for 3D printing technology. A 3D printer was used to transform computational models into a physical duplicate with small losses in spatial accuracy and to generate tissue-equivalent materials characterized for diagnostic energy x-rays. A series of pregnant abdomens were selected as prototypes because of their large size and complex modeling. The process involved the following steps: segmentation of anatomy used for modeling; transformation of the computational model into a printing file format; preparation, characterization, and introduction of phantom materials; and model removal and phantom assembly. RESULTS The density of the homogenized soft tissue-equivalent substitute was optimized by combining 9.0% by weight of urethane filler powder and 91.0% urethane polymer, which resulted in a mean density of 1.041 g/cm3 measured over 20 samples. Density varied among all of the samples by 0.0026 g/cm3. The total variation in density was 0.00261 g/cm3. The half-value layer of the bone material was measured to be 1.7 mm of bone material at 120 kVp and when simulated by use of the density of the bone tissue-equivalent substitute (1.60 g/cm3) was determined to be 1.61 mm of bone tissue. For dosimetry purposes the phantom provided excellent results for evaluating a site's protocol based on scan range. CONCLUSION The 3D printing technology is applicable to the fabrication of phantoms used for performing dosimetry. The tissue-equivalent materials used to substitute for the soft tissue were developed to be highly adaptable for optimization based on the dosimetry application. Use of this method resulted in more automated phantom construction with decreased construction time and increased out-of-slice spatial resolution of the phantoms.
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Kim CG. Exposure dose reduction during lateral spine test with water filter. Technol Health Care 2016; 24:429-38. [DOI: 10.3233/thc-151120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Meinel FG, Henzler T, Schoepf UJ, Park PW, Huda W, Spearman JV, Dyer KT, Rao AG, Hlavacek AM. ECG-synchronized CT angiography in 324 consecutive pediatric patients: spectrum of indications and trends in radiation dose. Pediatr Cardiol 2015; 36:569-78. [PMID: 25380963 DOI: 10.1007/s00246-014-1051-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 10/31/2014] [Indexed: 11/25/2022]
Abstract
The aim of the study is to describe the spectrum of indications for pediatric ECG-synchronized CT angiography (CTA), the main determinants of radiation exposure, and trends in radiation dose over time at a single, tertiary referral center. The study was IRB approved and HIPAA compliant with informed consent waived. Between 2005 and 2013, 324 pediatric patients underwent ECG-synchronized CTA to evaluate known or suspected cardiovascular abnormalities (109 female, median age 8.1 years). The effective dose (ED) was calculated using age-specific correction factors. Univariate and multivariate regression analyses were performed to identify predictors of radiation dose. The most common primary indications for the CTA examinations included known or suspected coronary pathologies (n = 166), complex congenital heart disease (n = 73), and aortic pathologies (n = 41). Median radiation exposure decreased from 12 mSv for patients examined in the years 2005-2007 to 1.2 mSv for patients examined in the years 2011-2013 (p < 0.001). Patients scanned using a tube potential of 80 kV (n = 259) had a significantly lower median radiation dose (1.4 mSv) compared to patients who were scanned at 100 kV (n = 46, median 6.3 mSv) or 120 kV (n = 19, median 19 mSv, p < 0.001). Tube voltage, followed by tube current and the method of ECG-synchronization were the strongest independent predictors of radiation dose. Growing experience with dose-saving techniques and CTA protocols tailored to the pediatric population have led to a tenfold reduction in radiation dose over recent years and now allow routinely performing ECG-synchronized CTA in children with a radiation dose on the order of 1 mSv.
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Affiliation(s)
- Felix G Meinel
- Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, MSC 226, Charleston, SC, 29401, USA
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Trattner S, Cheng B, Pieniazek RL, Hoffmann U, Douglas PS, Einstein AJ. Sample size requirements for estimating effective dose from computed tomography using solid-state metal-oxide-semiconductor field-effect transistor dosimetry. Med Phys 2014; 41:042102. [PMID: 24694150 DOI: 10.1118/1.4868693] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Effective dose (ED) is a widely used metric for comparing ionizing radiation burden between different imaging modalities, scanners, and scan protocols. In computed tomography (CT), ED can be estimated by performing scans on an anthropomorphic phantom in which metal-oxide-semiconductor field-effect transistor (MOSFET) solid-state dosimeters have been placed to enable organ dose measurements. Here a statistical framework is established to determine the sample size (number of scans) needed for estimating ED to a desired precision and confidence, for a particular scanner and scan protocol, subject to practical limitations. METHODS The statistical scheme involves solving equations which minimize the sample size required for estimating ED to desired precision and confidence. It is subject to a constrained variation of the estimated ED and solved using the Lagrange multiplier method. The scheme incorporates measurement variation introduced both by MOSFET calibration, and by variation in MOSFET readings between repeated CT scans. Sample size requirements are illustrated on cardiac, chest, and abdomen-pelvis CT scans performed on a 320-row scanner and chest CT performed on a 16-row scanner. RESULTS Sample sizes for estimating ED vary considerably between scanners and protocols. Sample size increases as the required precision or confidence is higher and also as the anticipated ED is lower. For example, for a helical chest protocol, for 95% confidence and 5% precision for the ED, 30 measurements are required on the 320-row scanner and 11 on the 16-row scanner when the anticipated ED is 4 mSv; these sample sizes are 5 and 2, respectively, when the anticipated ED is 10 mSv. CONCLUSIONS Applying the suggested scheme, it was found that even at modest sample sizes, it is feasible to estimate ED with high precision and a high degree of confidence. As CT technology develops enabling ED to be lowered, more MOSFET measurements are needed to estimate ED with the same precision and confidence.
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Affiliation(s)
- Sigal Trattner
- Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032
| | - Bin Cheng
- Department of Biostatistics, Columbia University Mailman School of Public Health, New York, New York 10032
| | - Radoslaw L Pieniazek
- Center for Radiological Research, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032
| | - Udo Hoffmann
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114
| | - Pamela S Douglas
- Department of Medicine, Division of Cardiology, Duke University, Durham, North Carolina 27715
| | - Andrew J Einstein
- Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York and Department of Radiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York
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Yang JCT, Lin MT, Jaw FS, Chen SJ, Wang JK, Shih TTF, Wu MH, Li YW. Trends in the utilization of computed tomography and cardiac catheterization among children with congenital heart disease. J Formos Med Assoc 2014; 114:1061-8. [PMID: 25241602 PMCID: PMC7126232 DOI: 10.1016/j.jfma.2014.08.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/29/2014] [Accepted: 08/04/2014] [Indexed: 11/15/2022] Open
Abstract
Background/Purpose Pediatric cardiac computed tomography (CT) is a noninvasive imaging modality used to clearly demonstrate the anatomical detail of congenital heart diseases. We investigated the impact of cardiac CT on the utilization of cardiac catheterization among children with congenital heart disease. Methods The study sample consisted of 2648 cardiac CT and 3814 cardiac catheterization from 1999 to 2009 for congenital heart diseases. Diagnoses were categorized into 11 disease groups. The numbers of examination, according to the different modalities, were compared using temporal trend analyses. The estimated effective radiation doses (mSv) of CT and catheterization were calculated and compared. Results The number of CT scans and interventional catheterizations had a slight annual increase of 1.2% and 2.7%, respectively, whereas that of diagnostic catheterization decreased by 6.2% per year. Disease groups fell into two categories according to utilization trend differences between CT and diagnostic catheterization. The increased use of CT reduces the need for diagnostic catheterization in patients with atrioventricular connection disorder, coronary arterial disorder, great vessel disorder, septal disorder, tetralogy of Fallot, and ventriculoarterial connection disorder. Clinicians choose either catheterization or CT, or both examinations, depending on clinical conditions, in patients with semilunar valvular disorder, heterotaxy, myocardial disorder, pericardial disorder, and pulmonary vein disorder. The radiation dose of CT was lower than that of diagnostic cardiac catheterization in all age groups. Conclusion The use of noninvasive CT in children with selected heart conditions might reduce the use of diagnostic cardiac catheterization. This may release time and facilities within the catheterization laboratory to meet the increasing demand for cardiac interventions.
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Affiliation(s)
- Justin Cheng-Ta Yang
- Institute of Biomedical Engineering, College of Engineering and College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan; College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Medical Imaging, National Taiwan University Hospital, Hsin-Chu Branch, Hsinchu, Taiwan; Department of Radiology, National Taiwan University Hospital, Chu-Tung Branch, Hsinchu, Taiwan
| | - Ming-Tai Lin
- College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan
| | - Fu-Shan Jaw
- Institute of Biomedical Engineering, College of Engineering and College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Shyh-Jye Chen
- Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan.
| | - Jou-Kou Wang
- College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan
| | | | - Mei-Hwan Wu
- College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan
| | - Yiu-Wah Li
- Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan
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Entrance skin dosimetry and size-specific dose estimate from pediatric chest CTA. J Cardiovasc Comput Tomogr 2013; 8:97-107. [PMID: 24211194 DOI: 10.1016/j.jcct.2013.08.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 03/27/2013] [Accepted: 08/16/2013] [Indexed: 02/08/2023]
Abstract
BACKGROUND Size-specific dose estimate (SSDE), which corrects CT dose index (CTDI) for body diameter and is a better measure of organ dose than is CTDI, has not yet been validated in vivo. OBJECTIVE The purpose was to determine the correlation between SSDE and measured breast entrance skin dose (ESD) for pediatric chest CT angiography across a variety of techniques, scanner models, and patient sizes. METHODS During 42 examinations done on 4 different scanners over 7 years, we measured mid-sternal ESD as an approximation of breast dose with skin dosimeters. We recorded age, weight, effective tube current, kilovoltage potential, console CTDI, and dose-length product, from which we calculated effective dose. We measured effective chest diameter to convert CTDI to SSDE, and we correlated SSDE with measured ESD, using linear regression. We evaluated image quality to answer the clinical question. RESULTS Patient mean (±SD) age was 8.4 ± 6.1 years (median, 7.9 years; range, 0.02-19.5 years); mean weight was 35 ± 27 kg (median, 26 kg; range, 3.5-115 kg); effective chest diameter was 20 ± 7 cm (median, 19 cm; range, 10-35 cm). Mean effective dose was 2.9 ± 2.8 mSv (median, 2.2 mSv; range, 0.1-14.4 mSv). We observed a linear correlation (R(2) = 0.98, P < .005) between SSDE (mean, 11 ± 11mGy; median, 7 mGy; range, 0.5-40 mGy) and breast ESD (mean, 12 ± 11 mGy; median, 7 mGy; range, 0.3-44 mGy). Our doses, which compared favorably with those previously reported, decreased significantly (P < .05) during the course of our study, because of the introduction of automatic exposure control, low kilovoltage, and high pitch techniques. All studies were of diagnostic quality. CONCLUSION SSDE is a valid dose measure in children undergoing chest CT angiography over a wide range of scanner platforms, techniques, and patient sizes, and it may be used to model breast dose and to document the results of dose reduction strategies.
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Chandrashekhar G, Sodhi KS, Saxena AK, Rohit MK, Khandelwal N. Correlation of 64 row MDCT, echocardiography and cardiac catheterization angiography in assessment of pulmonary arterial anatomy in children with cyanotic congenital heart disease. Eur J Radiol 2012; 81:4211-7. [DOI: 10.1016/j.ejrad.2012.08.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 07/06/2012] [Accepted: 08/15/2012] [Indexed: 10/27/2022]
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Sabarudin A, Sun Z, Ng KH. A systematic review of radiation dose associated with different generations of multidetector CT coronary angiography. J Med Imaging Radiat Oncol 2012; 56:5-17. [PMID: 22339741 DOI: 10.1111/j.1754-9485.2011.02335.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The purpose of this paper is to perform a systematic review on radiation dose reduction in coronary computed tomography (CT) angiography that is done using different generations of multidetector CT (MDCT) scanners ranging from four-slice to 320-slice CTs, and have different dose-saving techniques. The method followed was to search for references on coronary CT angiography (CTA) that had been published in English between 1998 and February 2011. The effective radiation dose reported in each study based on different generations of MDCT scanners was analysed and compared between the types of scanners, gender, exposure factors and scanning protocols. Sixty-six studies were eligible for inclusion in this analysis. The mean effective dose (ED) for MDCT angiography with retrospective electrocardiogram (ECG) gating without use of any dose-saving protocol was 6.0 ± 2.8, 10.4 ± 4.90 and 11.8 ± 5.9 mSv for four-slice, 16-slice and 64-slice CTs, respectively. More dose-saving strategies were applied in recent CT generations including prospective ECG-gating protocols, application of lower tube voltage and tube current modulation to achieve a noteworthy dose reduction. Prospective ECG-gating protocol was increasingly used in 64, 125, 256 and 320 slices with corresponding ED of 4.1 ± 1.7, 3.6 ± 0.4, 3.0 ± 1.9 and 7.6 ± 1.6 mSv, respectively. Lower tube voltage and tube current modulation were widely applied in 64-slice CT and resulted in significant dose reduction (P < 0.05). This analysis has shown that dose-saving strategies can substantially reduce the radiation dose in CT coronary angiography. The fact that more and more clinicians are opting for dose-saving strategies in CT coronary angiography indicates an increased awareness of risks associated with high radiation doses among them.
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Affiliation(s)
- Akmal Sabarudin
- Department of Imaging and Applied Physics, Curtin University, Perth, Western Australia, Australia
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Fearon T, Xie H, Cheng JY, Ning H, Zhuge Y, Miller RW. Patient-specific CT dosimetry calculation: a feasibility study. J Appl Clin Med Phys 2011; 12:3589. [PMID: 22089016 PMCID: PMC5718729 DOI: 10.1120/jacmp.v12i4.3589] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 06/01/2011] [Accepted: 05/17/2011] [Indexed: 12/03/2022] Open
Abstract
Current estimation of radiation dose from computed tomography (CT) scans on patients has relied on the measurement of Computed Tomography Dose Index (CTDI) in standard cylindrical phantoms, and calculations based on mathematical representations of “standard man”. Radiation dose to both adult and pediatric patients from a CT scan has been a concern, as noted in recent reports. The purpose of this study was to investigate the feasibility of adapting a radiation treatment planning system (RTPS) to provide patient‐specific CT dosimetry. A radiation treatment planning system was modified to calculate patient‐specific CT dose distributions, which can be represented by dose at specific points within an organ of interest, as well as organ dose‐volumes (after image segmentation) for a GE Light Speed Ultra Plus CT scanner. The RTPS calculation algorithm is based on a semi‐empirical, measured correction‐based algorithm, which has been well established in the radiotherapy community. Digital representations of the physical phantoms (virtual phantom) were acquired with the GE CT scanner in axial mode. Thermoluminescent dosimeter (TLDs) measurements in pediatric anthropomorphic phantoms were utilized to validate the dose at specific points within organs of interest relative to RTPS calculations and Monte Carlo simulations of the same virtual phantoms (digital representation). Congruence of the calculated and measured point doses for the same physical anthropomorphic phantom geometry was used to verify the feasibility of the method. The RTPS algorithm can be extended to calculate the organ dose by calculating a dose distribution point‐by‐point for a designated volume. Electron Gamma Shower (EGSnrc) codes for radiation transport calculations developed by National Research Council of Canada (NRCC) were utilized to perform the Monte Carlo (MC) simulation. In general, the RTPS and MC dose calculations are within 10% of the TLD measurements for the infant and child chest scans. With respect to the dose comparisons for the head, the RTPS dose calculations are slightly higher (10%–20%) than the TLD measurements, while the MC results were within 10% of the TLD measurements. The advantage of the algebraic dose calculation engine of the RTPS is a substantially reduced computation time (minutes vs. days) relative to Monte Carlo calculations, as well as providing patient‐specific dose estimation. It also provides the basis for a more elaborate reporting of dosimetric results, such as patient specific organ dose volumes after image segmentation. PACS numbers: 87.55.D‐, 87.57.Q‐, 87.53.Bn, 87.55.K‐
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Affiliation(s)
- Thomas Fearon
- Department of Diagnostic Imaging and Radiology and the Children’s Research Institute, Children’s National Medical Center, Washington, DC, USA.
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Hayabuchi Y, Inoue M, Watanabe N, Sakata M, Ohnishi T, Kagami S. Consideration of the Pathological Features of Pediatric Congenital Heart Diseases Which Are Ideally Suitable for Diagnosing With Multidetector-row CT. Cardiol Res 2011; 2:150-159. [PMID: 28352384 PMCID: PMC5358222 DOI: 10.4021/cr61w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2011] [Indexed: 11/25/2022] Open
Abstract
Background A lots of articles published regarding the usefulness of multidetector-row computed tomography (MDCT) in children with congenital heart disease (CHD) mostly describe that it can be an alternative to the invasive catheterization and angiography. The unique diagnostic features of this imaging modality have been largely ignored or disregarded. We described the pathological conditions that cannot be diagnosed by conventional angiography with cardiac catheterization but can be accurately diagnosed by MDCT. Methods We retrospectively reviewed non-ECG-gated MDCT images acquired from 452 children and young adults with CHD between 2005 and 2010 in our institute. In this article, we focused on the diagnostic advantages of MDCT, and indicated five pathological conditions. (1) When Blalock-Taussig shunt total occlusion prevents catheter insertion into the artificial vessel and angiography is ruled out, the peripheral pulmonary artery during the peripheral pulmonary artery can be imaged and diagnosed using MDCT based on blood flow supplied from many small collateral vessels originating from the aorta. (2) The location and protrusion of the device in the vessel after coil embolization to treat patent ductus arteriosus can be accurately visualized by virtual endoscopy using MDCT. (3) Calcification of patches, synthetic blood vessels, and other prostheses that is indistinct on conventional angiograms is clear on MDCT. (4) Simultaneous MDCT observations of the anatomical relationships between arterial and venous systems on the same image can clarify the detail diagnosis for surgical treatment. (5) Compression of the airways by the great vessels and pulmonary segmental emphysematous change can be diagnosed by MDCT. Results and Conclusions Among patients with CHD, MDCT is useful not only as a non-invasive alternative to conventional angiography, but also as a tool for specific morphological diagnoses. In the future, it will be necessary to accumulate experience in the recognition of cardiovascular conditions under which MDCT is necessary and to perform as the appropriate examination.
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Affiliation(s)
| | - Miki Inoue
- Department of Pediatrics, University of Tokushima, Tokushima, Japan
| | - Noriko Watanabe
- Department of Pediatrics, University of Tokushima, Tokushima, Japan
| | - Miho Sakata
- Department of Pediatrics, University of Tokushima, Tokushima, Japan
| | - Tatsuya Ohnishi
- Department of Pediatrics, University of Tokushima, Tokushima, Japan
| | - Shoji Kagami
- Department of Pediatrics, University of Tokushima, Tokushima, Japan
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Dougeni E, Faulkner K, Panayiotakis G. A review of patient dose and optimisation methods in adult and paediatric CT scanning. Eur J Radiol 2011; 81:e665-83. [PMID: 21684099 DOI: 10.1016/j.ejrad.2011.05.025] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2010] [Revised: 05/18/2011] [Accepted: 05/19/2011] [Indexed: 12/14/2022]
Abstract
An increasing number of publications and international reports on computed tomography (CT) have addressed important issues on optimised imaging practice and patient dose. This is partially due to recent technological developments as well as to the striking rise in the number of CT scans being requested. CT imaging has extended its role to newer applications, such as cardiac CT, CT colonography, angiography and urology. The proportion of paediatric patients undergoing CT scans has also increased. The published scientific literature was reviewed to collect information regarding effective dose levels during the most common CT examinations in adults and paediatrics. Large dose variations were observed (up to 32-fold) with some individual sites exceeding the recommended dose reference levels, indicating a large potential to reduce dose. Current estimates on radiation-related cancer risks are alarming. CT doses account for about 70% of collective dose in the UK and are amongst the highest in diagnostic radiology, however the majority of physicians underestimate the risk, demonstrating a decreased level of awareness. Exposure parameters are not always adjusted appropriately to the clinical question or to patient size, especially for children. Dose reduction techniques, such as tube-current modulation, low-tube voltage protocols, prospective echocardiography-triggered coronary angiography and iterative reconstruction algorithms can substantially decrease doses. An overview of optimisation studies is provided. The justification principle is discussed along with tools that assist clinicians in the decision-making process. There is the potential to eliminate clinically non-indicated CT scans by replacing them with alternative examinations especially for children or patients receiving multiple CT scans.
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Affiliation(s)
- E Dougeni
- Imaging Physics and Radiation Safety Section, Regional Medical Physics Department, Freeman Hospital, Freeman Road, Newcastle Upon Tyne NE7 7DN, UK.
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Al-Mousily F, Shifrin RY, Fricker FJ, Feranec N, Quinn NS, Chandran A. Use of 320-detector computed tomographic angiography for infants and young children with congenital heart disease. Pediatr Cardiol 2011; 32:426-32. [PMID: 21210093 DOI: 10.1007/s00246-010-9873-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 12/08/2010] [Indexed: 11/28/2022]
Abstract
Pediatric patients with complex congenital heart disease (CHD) face a lifetime of treatment with interventional therapeutic and palliative procedures. Echocardiography remains the mainstay for noninvasive imaging of congenital heart lesions. This often is supplemented with diagnostic cardiac catheterization for additional anatomic and physiologic characterization. However, recent technological improvements in computed tomography (CT) and magnetic resonance imaging (MRI) have led to an increased focus on the use of these techniques given their better safety profile. This study aimed to review the authors' experience with a 320-slice multidetector CT scanner in the evaluation of CHD in children. This retrospective case study investigated 22 infants and young children with a provisional diagnosis of CHD. Their anatomic evaluation was performed using a 320-slice Aquilon ONE CT scanner. Of these 22 patients, 14 were examined without cardiac gating. This was subsequently modified to a prospective gated, targeted protocol to decrease the radiation dose. The images were interpreted by an experienced radiologist and a pediatric cardiologist. Continuous variables were expressed as mean and standard deviation or range, and the two imaging protocols were compared. A comparison of exposure rates with those from other pediatric studies that had used the 64-slice CT angiography also was performed. For the first group of patients, with nongated CT examinations, the mean effective whole-body radiation dose was 1.8 ± 0.71 millisieverts (mSv) (range, 0.96-3.2 mSv). For the second group, the mean was 0.8 ± 0.39 mSv (range, 0.4-1.5 mSv). Although the radiation dose was reduced dramatically, clinicians must be vigilant about the cumulative risk of radiation exposure.
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Affiliation(s)
- Faris Al-Mousily
- Department of Pediatrics, University of Florida, P.O. Box 100296, Gainesville, FL 32610-0266, USA
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Radiation dose for thoracic and coronary step-and-shoot CT using a 128-slice dual-source machine in infants and small children with congenital heart disease. Pediatr Radiol 2011; 41:244-9. [PMID: 20821005 DOI: 10.1007/s00247-010-1804-6] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2010] [Revised: 06/15/2010] [Accepted: 07/01/2010] [Indexed: 02/08/2023]
Abstract
BACKGROUND For coronary artery visualization, retrospective ECG-gated acquisition by dual-source computed tomography (DSCT) was superior to spiral non-ECG-gated acquisition in a paediatric population of congenital heart disease (CHD) patients. However, retrospective cardiac CT is associated with substantial radiation doses to the patient. Recently, DSCT with end-systolic reconstruction was found to be robust for imaging the coronary arteries in patients with high heart rates. OBJECTIVE To evaluate step-and-shoot DSCT with end-systolic reconstruction for evaluating the heart, coronary arteries and other thoracic structures in young children with CHD. MATERIALS AND METHODS All neonates and children younger than 6 years of age who were referred to our institution for CHD evaluation between September and October 2009 were included in the study. ECG-gated DSCT was performed in sequential prospective mode centred on the systolic phase identified by ECG analysis. To assess the radiation dose, we recorded the dose-length product (DLP) in mGy·cm and the effective dose in mSv estimated from the DLP. Overall image quality was evaluated using a 5-grade scoring system and was assessed by looking at cardiac and vascular structures. The image quality for the proximal and middle segments of the right and left coronary arteries was also evaluated using a 5-grade scale. RESULTS Images of diagnostic quality (grade ≥ 3) were obtained in all 30 children with a mean image quality grade of 4.7 ± 0.6 (range, 3-5). Mean DLP was 5.7 ± 4.8 mGy*cm (range, 1-22 mGy cm) and mean effective radiation dose was 0.26 ± 0.16 mSv (range, 0.05-0.8 mSv). CONCLUSION Prospective ECG-gated thoracic DSCT at end-systole usually provides adequate thoracic and coronary artery image quality in neonates, infants and young children with CHD, independent of heart rate. This new method is associated with lower radiation doses compared to previous literature (mean effective dose, 0.26 mSv).
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Lee EY, Zurakowski D, Boiselle PM. Pulmonary embolism in pediatric patients survey of CT pulmonary angiography practices and policies. Acad Radiol 2010; 17:1543-9. [PMID: 20934355 DOI: 10.1016/j.acra.2010.08.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 07/15/2010] [Accepted: 08/05/2010] [Indexed: 12/28/2022]
Abstract
RATIONALE AND OBJECTIVES To determine the current policies and practices of Society for Pediatric Radiology (SPR) members regarding the evaluation of pediatric patients with suspected pulmonary embolism (PE) with an emphasis on use of computed tomography pulmonary angiography (CTPA). MATERIALS AND METHODS Institutional review board exemption was granted for this study. Surveys were mailed electronically to the 1575 members of the SPR representing 416 institutions. Information gathered included the existence of written policies, the imaging study of choice for suspected PE, routine acquisition of chest radiographs before CTPA, currently used CTPA techniques, modifications of protocols for radiation dose reduction, typical DLP (dose-length-product) for CTPA, and estimated annual frequency of performing CTPA for evaluating PE in children. Survey items pertaining to policies and practices were compared between practice settings and populations using chi-square analysis. RESULTS One hundred and sixty members representing 118 institutions responded, which resulted in a response rate of 28% (118/416), on an institutional basis. Of these 118 respondents, 104 (88%) perform CTPA in children with clinical suspicion of PE. Of the 104 respondents who perform CTPA, 26 (25%) have a written policy for CTPA, 93 (89%) perform CTPA as the first study choice, and 67 (64%) routinely obtain chest radiographs before CTPA. The most commonly used CTPA techniques in children with clinical suspicion of PE include intravenous contrast amount of 2 mL/kg, mechanical injection of intravenous contrast, and tailored bolus tracking method for CTPA scan initiation by observing the Hounsfield units of contrast in the central pulmonary artery on the monitoring scan. Sixty respondents (58%) modify CTPA imaging protocols for evaluating PE in children in order to decrease radiation dose. The two most common modifications for radiation dose reduction were reduced mAs in 41 (68%) and automatic exposure control in 38 (63%). The majority of respondents (88%) did not know the typical DLP for a 20-kg child during CTPA study performed to evaluate for PE. A significantly greater percentage of radiation dose-reduction techniques are performed within academic institutions compared with private institutions (P = .03). CONCLUSION Most survey respondents perform CTPA as the study of choice for evaluating PE in children, but there is considerable variability in their policies and practices. Respondents from academic medical centers are more likely to employ radiation dose-reduction techniques for CTPA than those in private practice settings.
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Hizli S, Ozdemir O, Abaci A, Razi CH, Kabakuş N. Relation of subepicardial adipose tissue thickness and clinical and metabolic parameters in obese prepubertal children. Pediatr Diabetes 2010; 11:556-62. [PMID: 20337974 DOI: 10.1111/j.1399-5448.2010.00644.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND The measurement of subepicardial adipose tissue thickness (SATT) has been found to be related to insulin resistance (IR) in adults. Until now, the association between SATT and IR has not been evaluated in obese prepubertal children. We aimed to determine the relation of SATT with clinical anthropometric and metabolic parameters and to provide cutoff value of SATT associated with IR in obese prepubertal children. METHODS Fifty-two obese (mean age: 9.5 ± 1.6 years, 29 female) and 31 lean prepubertal age- and gender-matched subjects (mean age: 9.2 ± 1.4 years, 12 female) were evaluated by echocardiography. SATT was measured by transthoracic echocardiography. RESULTS SATT (6.54 ± 1.38 mm) and homeostatic model assessment-insulin resistance (HOMA-IR) (3.2 ± 2) values of obese prepubertal subjects were significantly higher than those of the lean subjects (3.72 ± 0.57 mm and 1.6 ± 1) in the control group (both p < 0.001). Bivariate correlation analysis showed significant correlation between SATT, age, body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), mid-arm circumference (MAC), triceps skin fold (TSF) thickness, insulin, and HOMA-IR (r = 0.547, r = 0.524, r = 0.543, r = 0.431, r = 0.289, r = 0.402, r = 0.400, r = 0.328, r = 0.289, p < 0.05, respectively). As an optimal cutoff point, an SATT of 4.33 mm determined IR with 93.3% sensitivity and 51% specificity. CONCLUSIONS Our study on obese prepubertal children showed that SATT was significantly correlated with age, BMI, WC, HC, MAC, TSF, insulin, and HOMA-IR.
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Affiliation(s)
- Samil Hizli
- Department of Pediatric Gastroenterology, Hepatology and Nutrition, Kecioren Training and Research Hospital, Ankara, Turkey.
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16
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Mathewson JW. Three dimensional imaging using 64 detector row multi-slice CT should be used more widely for the diagnosis and management of congenital heart disease. J Saudi Heart Assoc 2010; 22:179-85. [PMID: 23960618 DOI: 10.1016/j.jsha.2010.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 07/13/2010] [Accepted: 07/14/2010] [Indexed: 11/16/2022] Open
Affiliation(s)
- James W Mathewson
- St. Joseph Hospital and Medical Center, Phoenix, Arizona, United States
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17
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Radiation dose and cancer risk from pediatric CT examinations on 64-slice CT: a phantom study. Eur J Radiol 2010; 76:e19-23. [PMID: 20363573 DOI: 10.1016/j.ejrad.2010.03.005] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 02/24/2010] [Accepted: 03/04/2010] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To measure the radiation dose from CT scans in an anthropomorphic phantom using a 64-slice MDCT, and to estimate the associated cancer risk. MATERIALS AND METHODS Organ doses were measured with a 5-year-old phantom and thermoluminescent dosimeters. Four protocols; head CT, thorax CT, abdomen CT and pelvis CT were studied. Cancer risks, in the form of lifetime attributable risk (LAR) of cancer incidence, were estimated by linear extrapolation using the organ radiation doses and the LAR data. RESULTS The effective doses for head, thorax, abdomen and pelvis CT, were 0.7mSv, 3.5mSv, 3.0mSv, 1.3mSv respectively. The organs with the highest dose were; for head CT, salivary gland (22.33mGy); for thorax CT, breast (7.89mGy); for abdomen CT, colon (6.62mGy); for pelvis CT, bladder (4.28mGy). The corresponding LARs for boys and girls were 0.015-0.053% and 0.034-0.155% respectively. The organs with highest LARs were; for head CT, thyroid gland (0.003% for boys, 0.015% for girls); for thorax CT, lung for boys (0.014%) and breast for girls (0.069%); for abdomen CT, colon for boys (0.017%) and lung for girls (0.016%); for pelvis CT, bladder for both boys and girls (0.008%). CONCLUSION The effective doses from these common pediatric CT examinations ranged from 0.7mSv to 3.5mSv and the associated lifetime cancer risks were found to be up to 0.16%, with some organs of higher radiosensitivity including breast, thyroid gland, colon and lungs.
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Joint quality improvement guidelines for pediatric arterial access and arteriography: from the Societies of Interventional Radiology and Pediatric Radiology. Pediatr Radiol 2010; 40:237-50. [PMID: 20058129 DOI: 10.1007/s00247-009-1499-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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19
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Heran MK, Marshalleck F, Temple M, Grassi CJ, Connolly B, Towbin RB, Baskin KM, Dubois J, Hogan MJ, Kundu S, Miller DL, Roebuck DJ, Rose SC, Sacks D, Sidhu M, Wallace MJ, Zuckerman DA, Cardella JF. Joint Quality Improvement Guidelines for Pediatric Arterial Access and Arteriography: From the Societies of Interventional Radiology and Pediatric Radiology. J Vasc Interv Radiol 2010; 21:32-43. [DOI: 10.1016/j.jvir.2009.09.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2009] [Revised: 09/16/2009] [Accepted: 09/27/2009] [Indexed: 11/28/2022] Open
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20
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Lee EY, Kritsaneepaiboon S, Zurakowski D, Arellano CMR, Strauss KJ, Boiselle PM. Beyond the Pulmonary Arteries: Alternative Diagnoses in Children With MDCT Pulmonary Angiography Negative for Pulmonary Embolism. AJR Am J Roentgenol 2009; 193:888-894. [DOI: 10.2214/ajr.09.2362] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Affiliation(s)
- Edward Y. Lee
- Department of Radiology and Department of Medicine, Pulmonary Division, Children's Hospital Boston and Harvard Medical School, 300 Longwood Ave., Boston, MA 02115
| | - Supika Kritsaneepaiboon
- Department of Radiology, Children's Hospital Boston and Harvard Medical School, Boston, MA
- Present address: Department of Radiology, Prince of Songkla University, Hat Yai, Thailand
| | - David Zurakowski
- Department of Anesthesiology, Children's Hospital Boston and Harvard Medical School, Boston, MA
| | - Claudia Martinez Rios Arellano
- Department of Radiology and Department of Medicine, Pulmonary Division, Children's Hospital Boston and Harvard Medical School, 300 Longwood Ave., Boston, MA 02115
| | - Keith J. Strauss
- Department of Radiology, Children's Hospital Boston and Harvard Medical School, Boston, MA
| | - Phillip M. Boiselle
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
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21
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Affiliation(s)
- D P Frush
- Division of Pediatric Radiology, McGovern-Davison Children's Health Center, Durham, NC 27710, USA.
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22
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Abstract
The role of imaging in cases of child abuse is to identify the extent of physical injury when abuse is present and to elucidate all imaging findings that point to alternative diagnoses. Effective diagnostic imaging of child abuse rests on high-quality technology as well as a full appreciation of the clinical and pathologic alterations occurring in abused children. This statement is a revision of the previous policy published in 2000.
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23
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Role of CT in the Evaluation of Congenital Cardiovascular Disease in Children. AJR Am J Roentgenol 2009; 192:1219-31. [PMID: 19380544 DOI: 10.2214/ajr.09.2382] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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24
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MDCT Pulmonary Angiography Evaluation of Pulmonary Embolism in Children. AJR Am J Roentgenol 2009; 192:1246-52. [DOI: 10.2214/ajr.08.1299] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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25
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Baker SR, Hsieh YHH, Maldjian PD, Scanlan MT. Inadvertent thyroid irradiation in protocol-driven trauma CT: a survey of hospital ERs. Emerg Radiol 2009; 16:203-7. [PMID: 19132426 DOI: 10.1007/s10140-008-0784-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Accepted: 12/02/2008] [Indexed: 10/24/2022]
Abstract
Given the well-recognized association of radiation and thyroid cancer, the objective of this study was to assess the frequency of radiation overlap at the level of the thyroid gland as part of standard protocols for computed tomography (CT) assessment of trauma, incorporating both cervical spine and chest images. A survey was sent to physician members of the American Society of Emergency Radiology. Among other questions, the respondents were asked to indicate their CT protocol with respect to the lower boundary of their cervical spine series and the upper boundary of their chest CT series. Forty-one surveys were returned. Of these, 83% reported overlap of the contiguous margins of the two CT studies resulting in partial or total double radiation deposition to the thyroid gland, which typically extends from vertebral levels C5 to T1. Sixty-one percent reported overlapping at T1 only, 15% at C7 to T1, 4.9% at C6 to T1, and 2.4% at C5 to T1. These data reveal that the predominant practice among the respondents is to include the thyroid gland in coincident CT studies of the cervical spine and chest in trauma protocols.
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Affiliation(s)
- Stephen R Baker
- New Jersey Medical School, University of Medicine & Dentistry of New Jersey, Newark, NJ 07101-1709, USA.
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26
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Eichhorn JG, Long FR, Jourdan C, Heverhagen JT, Hill SL, Raman SV, Cheatham JP. Usefulness of multidetector CT imaging to assess vascular stents in children with congenital heart disease: An in vivo and in vitro study. Catheter Cardiovasc Interv 2008; 72:544-51. [DOI: 10.1002/ccd.21680] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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De Lin M, Toncheva G, Nguyen G, Kim S, Anderson-Evans C, Johnson GA, Yoshizumi TT. Application of MOSFET detectors for dosimetry in small animal radiography using short exposure times. Radiat Res 2008; 170:260-3. [PMID: 18666818 DOI: 10.1667/rr1328.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2007] [Accepted: 05/01/2008] [Indexed: 11/03/2022]
Abstract
Digital subtraction angiography (DSA) X-ray imaging for small animals can be used for functional phenotyping given its ability to capture rapid physiological changes at high spatial and temporal resolution. The higher temporal and spatial requirements for small-animal imaging drive the need for short, high-flux X-ray pulses. However, high doses of ionizing radiation can affect the physiology. The purpose of this study was to verify and apply metal oxide semiconductor field effect transistor (MOSFET) technology to dosimetry for small-animal diagnostic imaging. A tungsten anode X-ray source was used to expose a tissue-equivalent mouse phantom. Dose measurements were made on the phantom surface and interior. The MOSFETs were verified with thermoluminescence dosimeters (TLDs). Bland-Altman analysis showed that the MOSFET results agreed with the TLD results (bias, 0.0625). Using typical small animal DSA scan parameters, the dose ranged from 0.7 to 2.2 cGy. Application of the MOSFETs in the small animal environment provided two main benefits: (1) the availability of results in near real-time instead of the hours needed for TLD processes and (2) the ability to support multiple exposures with different X-ray techniques (various of kVp, mA and ms) using the same MOSFET. This MOSFET technology has proven to be a fast, reliable small animal dosimetry method for DSA imaging and is a good system for dose monitoring for serial and gene expression studies.
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Affiliation(s)
- Ming De Lin
- Center for In Vivo Microscopy, Department of Biomedical Engineering, Duke University, Durham, NC 27710, USA
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28
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Evaluation of a coronary-cameral fistula: benefits of coronary dual-source MDCT angiography in children. Pediatr Radiol 2008; 38:874-8. [PMID: 18523763 DOI: 10.1007/s00247-008-0906-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Revised: 04/21/2008] [Accepted: 04/28/2008] [Indexed: 10/22/2022]
Abstract
We describe the use of a dual-source 64-channel multidetector array CT (MDCT) scanner in the evaluation of a coronary-cameral fistula in a 10-month-old boy. Echocardiography, cardiac catheterization, and MRI are modalities often used to evaluate congenital and other pediatric heart diseases. Radiation dose concerns and the absence of established protocols are factors that have potentially limited the use of CT for work-up in these young children. We present a case in which recent advances in technology allowed effective low-dose diagnostic quality coronary MDCT angiography in an infant.
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29
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Abstract
Advancing multidetector technology offers opportunities for improved vascular assessment in children. Much of what is available deals with thoracic and central nervous system applications, with very little written about abdominal applications. That said, many of the technical aspects are similar to computed tomography (CT) angiography in these regions and are worthy of reviewing, in addition to those unique considerations for abdominal CT angiography (CTA) in children. Familiarity with appropriate abdominal CTA for pediatric multidetector array CT will provide the same opportunities as CTA in other regions.
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30
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CT of Pediatric Vascular Stents Used to Treat Congenital Heart Disease. AJR Am J Roentgenol 2008; 190:1241-6. [PMID: 18430838 DOI: 10.2214/ajr.07.3194] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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31
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Arain NI, Batten LA, Cole JH. Computed tomography angiography of a coronary artery fistula. Pediatr Cardiol 2008; 29:234-5. [PMID: 17882477 DOI: 10.1007/s00246-007-9089-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Revised: 06/27/2007] [Accepted: 06/28/2007] [Indexed: 10/22/2022]
Affiliation(s)
- Nofil I Arain
- Department of Pediatrics, University of South Alabama, Mobile, AL 36604, USA
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32
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Bibliography. Current world literature. Cardiovascular medicine. Curr Opin Pediatr 2007; 19:601-6. [PMID: 17885483 DOI: 10.1097/mop.0b013e3282f12851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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33
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Arnold R, Ley S, Ley-Zaporozhan J, Eichhorn J, Schenk JP, Ulmer H, Kauczor HU. Visualization of coronary arteries in patients after childhood Kawasaki syndrome: value of multidetector CT and MR imaging in comparison to conventional coronary catheterization. Pediatr Radiol 2007; 37:998-1006. [PMID: 17768616 DOI: 10.1007/s00247-007-0566-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2007] [Revised: 05/09/2007] [Accepted: 05/29/2007] [Indexed: 12/25/2022]
Abstract
BACKGROUND After childhood Kawasaki syndrome (KS) the coronary arteries undergo a lifelong dynamic pathological change, and follow-up coronary artery imaging is essential. At present, conventional coronary catheterization (CCC) and angiography is still regarded as the gold standard. Less-invasive methods such as multidetector CT angiography (MDCT-A) and MRI have been used sporadically. OBJECTIVE To compare the diagnostic quality of MDCT-A and MRI with that of CCC for coronary imaging in a group of patients with coronary artery pathology after childhood KS. MATERIALS AND METHODS A total of 16 patients (aged 5-27 years) underwent CCC and 16-row MDCT-A and 14 patients MRI (1.5 T). RESULTS There was 100% agreement between MDCT-A and CCC in the detection of coronary aneurysms and stenoses. MDCT-A was superior for the visualization of calcified lesions. MRI and CCC showed 93% agreement for the detection of aneurysms. Visualization of coronary artery stenoses was difficult using MRI-one stenosis was missed. CONCLUSION MDCT-A has excellent correlation with CCC regarding all changes affecting the coronary arteries in the follow-up of childhood KS. In comparison to MDCT-A and CCC, MRI is less precise in the detection of stenotic lesions. Due to its high image quality and ease of performance MDCT-A should be the primary diagnostic modality in patients following childhood KS.
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Affiliation(s)
- Raoul Arnold
- Department of Paediatric Cardiology, University Hospital, Heidelberg, Germany.
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Hollingsworth CL, Yoshizumi TT, Frush DP, Chan FP, Toncheva G, Nguyen G, Lowry CR, Hurwitz LM. Pediatric Cardiac-Gated CT Angiography: Assessment of Radiation Dose. AJR Am J Roentgenol 2007; 189:12-8. [PMID: 17579144 DOI: 10.2214/ajr.06.1507] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of our study was to determine a dose range for cardiac-gated CT angiography (CTA) in children. MATERIALS AND METHODS ECG-gated cardiac CTA simulating scanning of the heart was performed on an anthropomorphic phantom of a 5-year-old child on a 16-MDCT scanner using variable parameters (small field of view; 16 x 0.625 mm configuration; 0.5-second gantry cycle time; 0.275 pitch; 120 kVp at 110, 220, and 330 mA; and 80 kVp at 385 mA). Metal oxide semiconductor field effect transistor (MOSFET) technology measured 20 organ doses. Effective dose calculated using the dose-length product (DLP) was compared with effective dose determined from measured absorbed organ doses. RESULTS Highest organ doses included breast (3.5-12.6 cGy), lung (3.3-12.1 cGy), and bone marrow (1.7-7.6 cGy). The 80 kVp/385 mA examination produced lower radiation doses to all organs than the 120 kVp/220 mA examination. MOSFET effective doses (+/- SD) were as follows: 110 mA: 7.4 mSv (+/- 0.6 mSv), 220 mA: 17.2 mSv (+/- 0.3 mSv), 330 mA: 25.7 mSv (+/- 0.3 mSv), 80 kVp/385 mA: 10.6 mSv (+/- 0.2 mSv). DLP effective doses for diagnostic runs were as follows: 110 mA: 8.7 mSv, 220 mA: 19 mSv, 330 mA: 28 mSv, 80 kVp/385 mA: 12 mSv. DLP effective doses exceeded MOSFET effective doses by 9.7-17.2%. CONCLUSION Radiation doses for a 5-year-old during cardiac-gated CTA vary greatly depending on parameters. Organ doses can be high; the effective dose may reach 28.4 mSv. Further work, including determination of size-appropriate mA and image quality, is important before routine use of this technique in children.
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Affiliation(s)
- Caroline L Hollingsworth
- Department of Radiology, Division of Pediatric Radiology, 1905 McGovern-Davison Children's Health Center, Durham, NC 27710, USA.
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Dauer LT, Casciotta KA, Erdi YE, Rothenberg LN. Radiation dose reduction at a price: the effectiveness of a male gonadal shield during helical CT scans. BMC Med Imaging 2007; 7:5. [PMID: 17367529 PMCID: PMC1831769 DOI: 10.1186/1471-2342-7-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Accepted: 03/16/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND It is estimated that 60 million computed tomography (CT) scans were performed during 2006, with approximately 11% of those performed on children age 0-15 years. Various types of gonadal shielding have been evaluated for reducing exposure to the gonads. The purpose of this study was to quantify the radiation dose reduction to the gonads and its effect on image quality when a wrap-around male pediatric gonad shield was used during CT scanning. This information is obtained to assist the attending radiologist in the decision to utilize such male gonadal shields in pediatric imaging practice. METHODS The dose reduction to the gonads was measured for both direct radiation and for indirect scattered radiation from the abdomen. A 6 cm3 ion chamber (Model 10X5-6, Radcal Corporation, Monrovia, CA) was placed on a Humanoid real bone pelvic phantom at a position of the male gonads. When exposure measurements with shielding were made, a 1 mm lead wrap-around gonadal shield was placed around the ion chamber sensitive volume. RESULTS The use of the shields reduced scatter dose to the gonads by a factor of about 2 with no appreciable loss of image quality. The shields reduced the direct beam dose by a factor of about 35 at the expense of extremely poor CT image quality due to severe streak artifacts. CONCLUSION Images in the direct exposure case are not useful due to these severe artifacts and the difficulties in positioning these shields on patients in the scatter exposure case may not be warranted by the small absolute reduction in scatter dose unless it is expected that the patient will be subjected to numerous future CT scans.
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Affiliation(s)
- Lawrence T Dauer
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Ave. New York, NY 10021, USA
| | - Kevin A Casciotta
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Ave. New York, NY 10021, USA
| | - Yusuf E Erdi
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Ave. New York, NY 10021, USA
| | - Lawrence N Rothenberg
- Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York Ave. New York, NY 10021, USA
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