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Papadimitroulas P, Balomenos A, Kopsinis Y, Loudos G, Alexakos C, Karnabatidis D, Kagadis GC, Kostou T, Chatzipapas K, Visvikis D, Mountris KA, Jaouen V, Katsanos K, Diamantopoulos A, Apostolopoulos D. A Review on Personalized Pediatric Dosimetry Applications Using Advanced Computational Tools. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2019. [DOI: 10.1109/trpms.2018.2876562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Pediatric CT radiation exposure: where we were, and where we are now. Pediatr Radiol 2019; 49:469-478. [PMID: 30923878 DOI: 10.1007/s00247-018-4281-y] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/24/2018] [Accepted: 10/05/2018] [Indexed: 01/01/2023]
Abstract
Since the turn of the last millennium, the pediatric radiology community has blazed a patient-quality and safety trail in helping to effectively address the public and the news media's concerns about the implications of ionizing radiation from CT scanners in children. As such, this article (1) reviews the potential deleterious effects of ionizing radiation, (2) discusses why limiting radiation exposure in children is so important, (3) tells the history of pediatric CT radiation exposure concerns, (4) explains the interventions that took place to address these concerns and (5) touches on the current school of thought on pediatric CT dose reduction.
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Azizi AA, Slavc I, Theisen BE, Rausch I, Weber M, Happak W, Aszmann O, Hojreh A, Peyrl A, Amann G, Benkoe TM, Wadsak W, Kasprian G, Staudenherz A, Hacker M, Traub-Weidinger T. Monitoring of plexiform neurofibroma in children and adolescents with neurofibromatosis type 1 by [ 18 F]FDG-PET imaging. Is it of value in asymptomatic patients? Pediatr Blood Cancer 2018; 65. [PMID: 28771999 DOI: 10.1002/pbc.26733] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 06/20/2017] [Accepted: 07/02/2017] [Indexed: 12/27/2022]
Abstract
PURPOSE About 10% of patients with neurofibromatosis type 1 (NF-1) develop malignant peripheral nerve sheath tumours (MPNST) mostly arising in plexiform neurofibroma (PN); 15% of MPNST arise in children and adolescents. 2-[18 F]fluoro-2-deoxy-d-glucose ([18 F]FDG)-PET (where PET is positron emission tomography) is a sensitive method in differentiating PN and MPNST in symptomatic patients with NF-1. This study assesses the value of [18 F]FDG-PET imaging in detecting malignant transformation in symptomatic and asymptomatic children with PN. METHODS Forty-one patients with NF-1 and extensive PN underwent prospective [18 F]FDG imaging from 2003 to 2014. Thirty-two of the patients were asymptomatic. PET data, together with histological results and clinical course were re-evaluated retrospectively. Maximum standardised uptake values (SUVmax) and lesion-to-liver ratio were assessed. RESULTS A total of 104 examinations were performed. Mean age at first PET was 13.5 years (2.6-22.6). Eight patients had at least one malignant lesion; four of these patients were asymptomatic. Two of four symptomatic patients died, while all patients with asymptomatic malignant lesions are alive. All malignant tumours could be identified by PET imaging in both symptomatic and asymptomatic patients. All lesions judged as benign by [18 F]FDG imaging and clinical judgment were either histologically benign if removed or remained clinically silent during follow-up. SUVmax of malignant and benign lesions overlapped, but no malignant lesion showed FDG uptake ≤3.15. Asymptomatic malignant lesions were detected with a sensitivity of 100%, a negative predictive value of 100% and a specificity of 45.1%. CONCLUSION Malignant transformation of PN also occurs in asymptomatic children and adolescents. Detection of MPNST at early stages could increase the possibility of oncologically curative resections.
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Affiliation(s)
- Amedeo A Azizi
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Irene Slavc
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Benjamin Emile Theisen
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Ivo Rausch
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Michael Weber
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Happak
- Department of Surgery, Medical University of Vienna, Vienna, Austria
| | - Oskar Aszmann
- Department of Surgery, Medical University of Vienna, Vienna, Austria
| | - Azadeh Hojreh
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Andreas Peyrl
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Gabriele Amann
- Department of Clinical Pathology, Medical University of Vienna, Vienna, Austria
| | - Thomas M Benkoe
- Department of Surgery, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Wadsak
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Gregor Kasprian
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Anton Staudenherz
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Marcus Hacker
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Tatjana Traub-Weidinger
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
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Kim SY, Kim HS, Park MH, Lee JH, Oh SH, Chang SO, Kim CS, Jung AY, Kim YH. Optimal use of CT imaging in pediatric congenital cholesteatoma. Auris Nasus Larynx 2017; 44:266-271. [DOI: 10.1016/j.anl.2016.07.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 07/06/2016] [Accepted: 07/12/2016] [Indexed: 10/21/2022]
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Han BK, Rigsby CK, Leipsic J, Bardo D, Abbara S, Ghoshhajra B, Lesser JR, Raman SV, Crean AM, Nicol ED, Siegel MJ, Hlavacek A. Computed Tomography Imaging in Patients with Congenital Heart Disease, Part 2: Technical Recommendations. An Expert Consensus Document of the Society of Cardiovascular Computed Tomography (SCCT). J Cardiovasc Comput Tomogr 2015; 9:493-513. [DOI: 10.1016/j.jcct.2015.07.007] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 07/17/2015] [Indexed: 02/06/2023]
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Kharbanda AB, Krause E, Lu Y, Blumberg K. Analysis of radiation dose to pediatric patients during computed tomography examinations. Acad Emerg Med 2015; 22:670-5. [PMID: 26010148 DOI: 10.1111/acem.12689] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Revised: 12/11/2014] [Accepted: 12/17/2014] [Indexed: 12/15/2022]
Abstract
BACKGROUND Computed tomography (CT) utilization has increased rapidly over the past 15 years. CT is the most common source for radiation exposure. OBJECTIVES The objective was to measure the effective dose of radiation delivered during routine head and abdominal CT examinations at a children's hospital. METHODS This was a retrospective study of emergency department (ED) patients < 20 years of age who underwent head or abdominal CT scans in 2012 at a single children's hospital. The authors abstracted the dose-length product from the CT scanners and calculated the effective radiation dose delivered. Patient demographics were abstracted from the medical record. The relationship between effective dose and age, patient weight, and reason for examination were evaluated. RESULTS A total of 478 subjects were included: 255 underwent head CT, and 223 underwent abdominal CT. The median age was 8.1 years (interquartile range = 2.71 to 14.40 years) and 56.9% were male. The median effective dose for head CT was 2.68 mSv (95% confidence interval [CI] = 2.54 to 2.84 mSv) and decreased as age increased. For abdominal CT, the median effective dose was 5.06 mSv (95% CI = 4.58 to 6.03 mSv) and increased as age increased (3.67 to 11.12 mSv, p < 0.001). For abdominal CT, 8% of 5- to 10-year-olds, 28% of those 10 to 15 years, and 60% of patients over age 15 years received effective doses over 10 mSv. CONCLUSIONS The amount of radiation delivered to pediatric patients during routine CT examinations of the head and abdomen was low. Regardless, a large proportion of older patients were exposed to elevated effective doses of radiation during abdominal CT.
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Affiliation(s)
- Anupam B. Kharbanda
- The Department of Pediatric Emergency Medicine; Children's Hospitals and Clinics of Minnesota; Minneapolis MN
| | - Ernest Krause
- The Department of Research and Sponsored Programs; Children's Hospitals and Clinics of Minnesota; Minneapolis MN
| | - Yi Lu
- The Department of Research and Sponsored Programs; Children's Hospitals and Clinics of Minnesota; Minneapolis MN
| | - Karen Blumberg
- The Department of Radiology; Children's Hospitals and Clinics of Minnesota; Minneapolis MN
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Strauss KJ. Dose indices: everybody wants a number. Pediatr Radiol 2014; 44 Suppl 3:450-9. [PMID: 25304704 DOI: 10.1007/s00247-014-3104-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 05/27/2014] [Accepted: 06/19/2014] [Indexed: 11/24/2022]
Abstract
This paper discusses the merits and weaknesses of the standard terms that have been developed to quantify CT dose: CT dose indices (CTDI), dose length product (DLP) and effective dose. The difference between the measured CTDIvol and the CTDIvol displayed on the CT scanner illustrates a clinical dilemma. Displayed CTDIvol represents the radiation dose delivered to a plastic phantom, which is significantly different from the dose delivered to the patient, depending on the size of the patient. Although effective dose is simple to calculate for an individual patient, it was never intended for this purpose. The need for a simple, appropriate method to estimate pediatric patient doses led to the development of the size-specific dose estimate (SSDE), the newest CT dose index. Here I compare SSDE and its merits to the use of effective dose to estimate patient dose. The discussion concludes with a few sample calculations and basic clinical applications of SSDE to better quantify pediatric patient dose from CT scans.
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Affiliation(s)
- Keith J Strauss
- Department of Radiology, Cincinnati Children's Hospital Medical Center, MLC 50311, 3333 Burnet Ave., Cincinnati, OH, 45229-3026, USA,
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Han BK, Lesser JR. Cardiac CT in the Diagnosis and Postoperative Assessment of Congenital Heart Disease. CURRENT CARDIOVASCULAR IMAGING REPORTS 2013. [DOI: 10.1007/s12410-013-9195-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Mathews JD, Forsythe AV, Brady Z, Butler MW, Goergen SK, Byrnes GB, Giles GG, Wallace AB, Anderson PR, Guiver TA, McGale P, Cain TM, Dowty JG, Bickerstaffe AC, Darby SC. Cancer risk in 680,000 people exposed to computed tomography scans in childhood or adolescence: data linkage study of 11 million Australians. BMJ 2013; 346:f2360. [PMID: 23694687 PMCID: PMC3660619 DOI: 10.1136/bmj.f2360] [Citation(s) in RCA: 1287] [Impact Index Per Article: 117.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To assess the cancer risk in children and adolescents following exposure to low dose ionising radiation from diagnostic computed tomography (CT) scans. DESIGN Population based, cohort, data linkage study in Australia. COHORT MEMBERS: 10.9 million people identified from Australian Medicare records, aged 0-19 years on 1 January 1985 or born between 1 January 1985 and 31 December 2005; all exposures to CT scans funded by Medicare during 1985-2005 were identified for this cohort. Cancers diagnosed in cohort members up to 31 December 2007 were obtained through linkage to national cancer records. MAIN OUTCOME Cancer incidence rates in individuals exposed to a CT scan more than one year before any cancer diagnosis, compared with cancer incidence rates in unexposed individuals. RESULTS 60,674 cancers were recorded, including 3150 in 680,211 people exposed to a CT scan at least one year before any cancer diagnosis. The mean duration of follow-up after exposure was 9.5 years. Overall cancer incidence was 24% greater for exposed than for unexposed people, after accounting for age, sex, and year of birth (incidence rate ratio (IRR) 1.24 (95% confidence interval 1.20 to 1.29); P<0.001). We saw a dose-response relation, and the IRR increased by 0.16 (0.13 to 0.19) for each additional CT scan. The IRR was greater after exposure at younger ages (P<0.001 for trend). At 1-4, 5-9, 10-14, and 15 or more years since first exposure, IRRs were 1.35 (1.25 to 1.45), 1.25 (1.17 to 1.34), 1.14 (1.06 to 1.22), and 1.24 (1.14 to 1.34), respectively. The IRR increased significantly for many types of solid cancer (digestive organs, melanoma, soft tissue, female genital, urinary tract, brain, and thyroid); leukaemia, myelodysplasia, and some other lymphoid cancers. There was an excess of 608 cancers in people exposed to CT scans (147 brain, 356 other solid, 48 leukaemia or myelodysplasia, and 57 other lymphoid). The absolute excess incidence rate for all cancers combined was 9.38 per 100,000 person years at risk, as of 31 December 2007. The average effective radiation dose per scan was estimated as 4.5 mSv. CONCLUSIONS The increased incidence of cancer after CT scan exposure in this cohort was mostly due to irradiation. Because the cancer excess was still continuing at the end of follow-up, the eventual lifetime risk from CT scans cannot yet be determined. Radiation doses from contemporary CT scans are likely to be lower than those in 1985-2005, but some increase in cancer risk is still likely from current scans. Future CT scans should be limited to situations where there is a definite clinical indication, with every scan optimised to provide a diagnostic CT image at the lowest possible radiation dose.
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Affiliation(s)
- John D Mathews
- School of Population and Global Health, University of Melbourne, Carlton, Vic 3053, Australia
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Pulmonary CT Angiography as First-Line Imaging for PE: Image Quality and Radiation Dose Considerations. AJR Am J Roentgenol 2013; 200:522-8. [PMID: 23436840 DOI: 10.2214/ajr.12.9928] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Comparison of Different Methods of Calculating CT Radiation Effective Dose in Children. AJR Am J Roentgenol 2012; 199:W232-9. [DOI: 10.2214/ajr.10.5895] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Feasibility of using single-slice MDCT to evaluate visceral abdominal fat in an urban pediatric population. AJR Am J Roentgenol 2011; 197:482-7. [PMID: 21785098 DOI: 10.2214/ajr.10.5514] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Obesity is a growing clinical problem, especially among children of low socioeconomic status. Increased visceral abdominal fat is implicated in the metabolic syndrome and its health consequences. The purpose of this study is to validate measurement of a single MDCT slice as a predictor of total visceral abdominal fat and to correlate over a wide range of body mass indexes (BMIs). MATERIALS AND METHODS A two-phase retrospective analysis was performed. For validation, MDCTs of 21 consecutive healthy children (8-14 years old) were reviewed. In these cases, visceral abdominal fat and subcutaneous abdominal fat area were calculated using a body fat analysis function from single 0.625-mm MDCT slices at the umbilicus and were compared with total visceral abdominal fat area as measured from T11 to the coccyx. Subsequently, visceral abdominal fat area was obtained from single slices at the umbilicus from abdominal MDCT scans of 146 consecutive healthy children (age range, 6-14 years; 80 boys and 66 girls; 77 Hispanic, 41 African American, 15 white, and 13 multiracial or other race) for whom BMI was available. Associations between visceral abdominal fat area and sex, race, and BMI were determined. Effective radiation dose for a 1.25-mm axial MDCT slice was calculated using a mathematic model that uses derived scaling factors for pediatric patients. RESULTS Visceral abdominal fat area obtained from a 0.625-mm slice at the umbilicus was highly correlated with total visceral abdominal fat area (r = 0.96; p < 0.0001). Visceral abdominal fat area from single slices at the umbilicus was significantly correlated with BMI (r = 0.72; p < 0.0001). Umbilical visceral abdominal fat area was significantly lower in African American children compared with others (median, 14 vs 22 cm(2); p = 0.02) and was not associated with sex. In our population, the effective radiation dose from the smallest obtainable slice was 0.015-0.019 mSv/37-54 kg of patient weight. CONCLUSION Visceral abdominal fat area calculated from a single abdominal MDCT slice obtained in children is highly correlated with total visceral abdominal fat and with BMI and involves limited radiation exposure.
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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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Li X, Samei E, Segars WP, Sturgeon GM, Colsher JG, Frush DP. Patient-specific radiation dose and cancer risk for pediatric chest CT. Radiology 2011; 259:862-74. [PMID: 21467251 DOI: 10.1148/radiol.11101900] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
PURPOSE To estimate patient-specific radiation dose and cancer risk for pediatric chest computed tomography (CT) and to evaluate factors affecting dose and risk, including patient size, patient age, and scanning parameters. MATERIALS AND METHODS The institutional review board approved this study and waived informed consent. This study was HIPAA compliant. The study included 30 patients (0-16 years old), for whom full-body computer models were recently created from clinical CT data. A validated Monte Carlo program was used to estimate organ dose from eight chest protocols, representing clinically relevant combinations of bow tie filter, collimation, pitch, and tube potential. Organ dose was used to calculate effective dose and risk index (an index of total cancer incidence risk). The dose and risk estimates before and after normalization by volume-weighted CT dose index (CTDI(vol)) or dose-length product (DLP) were correlated with patient size and age. The effect of each scanning parameter was studied. RESULTS Organ dose normalized by tube current-time product or CTDI(vol) decreased exponentially with increasing average chest diameter. Effective dose normalized by tube current-time product or DLP decreased exponentially with increasing chest diameter. Chest diameter was a stronger predictor of dose than weight and total scan length. Risk index normalized by tube current-time product or DLP decreased exponentially with both chest diameter and age. When normalized by DLP, effective dose and risk index were independent of collimation, pitch, and tube potential (<10% variation). CONCLUSION The correlations of dose and risk with patient size and age can be used to estimate patient-specific dose and risk. They can further guide the design and optimization of pediatric chest CT protocols. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101900/-/DC1.
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Affiliation(s)
- Xiang Li
- Department of Radiology, Duke University Medical Center, 2424 Erwin Rd, Suite 302, Durham, NC 27705, USA.
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Lam D, Wootton-Gorges SL, McGahan JP, Stern R, Boone JM. Abdominal pediatric cancer surveillance using serial computed tomography: evaluation of organ absorbed dose and effective dose. Semin Oncol 2011; 38:128-35. [PMID: 21362521 DOI: 10.1053/j.seminoncol.2010.11.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Computed tomography (CT) is used extensively in cancer diagnosis, staging, evaluation of response to treatment, and in active surveillance for cancer reoccurrence. A review of CT technology is provided, at a level of detail appropriate for a busy clinician to review. The basis of x-ray CT dosimetry is also discussed, and concepts of absorbed dose and effective dose (ED) are distinguished. Absorbed dose is a physical quantity (measured in milligray [mGy]) equal to the x-ray energy deposited in a mass of tissue, whereas ED uses an organ-specific weighting method that converts organ doses to ED measured in millisieverts (mSv). The organ weighting values carry with them a measure of radiation risk, and so ED (in mSv) is not a physical dose metric but rather is one that conveys radiation risk. The use of CT in a cancer surveillance protocol was used as an example of a pediatric patient who had kidney cancer, with surgery and radiation therapy. The active use of CT for cancer surveillance along with diagnostic CT scans led to a total of 50 CT scans performed on this child in a 7-year period. It was estimated that the patient received an average organ dose of 431 mGy from these CT scans. By comparison, the radiation therapy was performed and delivered 50.4 Gy to the patient's abdomen. Thus, the total dose from CT represented only 0.8% of the patient's radiation dose.
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Affiliation(s)
- Diana Lam
- School of Medicine, University of California Davis Medical Center, Sacramento, CA, USA
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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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Berrington de González A, Mahesh M, Kim KP, Bhargavan M, Lewis R, Mettler F, Land C. Projected cancer risks from computed tomographic scans performed in the United States in 2007. ACTA ACUST UNITED AC 2010; 169:2071-7. [PMID: 20008689 DOI: 10.1001/archinternmed.2009.440] [Citation(s) in RCA: 1319] [Impact Index Per Article: 94.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND The use of computed tomographic (CT) scans in the United States (US) has increased more than 3-fold since 1993 to approximately 70 million scans annually. Despite the great medical benefits, there is concern about the potential radiation-related cancer risk. We conducted detailed estimates of the future cancer risks from current CT scan use in the US according to age, sex, and scan type. METHODS Risk models based on the National Research Council's "Biological Effects of Ionizing Radiation" report and organ-specific radiation doses derived from a national survey were used to estimate age-specific cancer risks for each scan type. These models were combined with age- and sex-specific scan frequencies for the US in 2007 obtained from survey and insurance claims data. We estimated the mean number of radiation-related incident cancers with 95% uncertainty limits (UL) using Monte Carlo simulations. RESULTS Overall, we estimated that approximately 29 000 (95% UL, 15 000-45 000) future cancers could be related to CT scans performed in the US in 2007. The largest contributions were from scans of the abdomen and pelvis (n = 14 000) (95% UL, 6900-25 000), chest (n = 4100) (95% UL, 1900-8100), and head (n = 4000) (95% UL, 1100-8700), as well as from chest CT angiography (n = 2700) (95% UL, 1300-5000). One-third of the projected cancers were due to scans performed at the ages of 35 to 54 years compared with 15% due to scans performed at ages younger than 18 years, and 66% were in females. CONCLUSIONS These detailed estimates highlight several areas of CT scan use that make large contributions to the total cancer risk, including several scan types and age groups with a high frequency of use or scans involving relatively high doses, in which risk-reduction efforts may be warranted.
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Affiliation(s)
- Amy Berrington de González
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD 20892, USA.
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Raman P, Raman R, Newman B, Venkatraman R, Raman B, Robinson TE. Development and validation of automated 2D-3D bronchial airway matching to track changes in regional bronchial morphology using serial low-dose chest CT scans in children with chronic lung disease. J Digit Imaging 2009; 23:744-54. [PMID: 19756866 DOI: 10.1007/s10278-009-9199-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 12/23/2008] [Accepted: 03/05/2009] [Indexed: 10/20/2022] Open
Abstract
To address potential concern for cumulative radiation exposure with serial spiral chest computed tomography (CT) scans in children with chronic lung disease, we developed an approach to match bronchial airways on low-dose spiral and low-dose high-resolution CT (HRCT) chest images to allow serial comparisons. An automated algorithm matches the position and orientation of bronchial airways obtained from HRCT slices with those in the spiral CT scan. To validate this algorithm, we compared manual matching vs automatic matching of bronchial airways in three pediatric patients. The mean absolute percentage difference between the manually matched spiral CT airway and the index HRCT airways were 9.4 ± 8.5% for the internal diameter measurements, 6.0 ± 4.1% for the outer diameter measurements, and 10.1 ± 9.3% for the wall thickness measurements. The mean absolute percentage difference between the automatically matched spiral CT airway measurements and index HRCT airway measurements were 9.2 ± 8.6% for the inner diameter, 5.8 ± 4.5% for the outer diameter, and 9.9 ± 9.5% for the wall thickness. The overall difference between manual and automated methods was 2.1 ± 1.2%, which was significantly less than the interuser variability of 5.1 ± 4.6% (p<0.05). Tests of equivalence had p<0.05, demonstrating no significant difference between the two methods. The time required for matching was significantly reduced in the automated method (p<0.01) and was as accurate as manual matching, allowing efficient comparison of airways obtained on low-dose spiral CT imaging with low-dose HRCT scans.
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Affiliation(s)
- Pavithra Raman
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305-5105, USA
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Huda W, Nickoloff EL, Boone JM. Overview of patient dosimetry in diagnostic radiology in the USA for the past 50 years. Med Phys 2009; 35:5713-28. [PMID: 19175129 DOI: 10.1118/1.3013604] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
This review covers the role of medical physics in addressing issues directly related to patient dosimetry in radiography, fluoroscopy, mammography, and CT. The sections on radiography and fluoroscopy radiation doses review the changes that have occurred during the last 50 to 60 years. A number of technological improvements have contributed to both a significant reduction in patient and staff radiation doses and improvements to the image quality during this period of time. There has been a transition from film-screen radiography with hand dip film processing to electronic digital imaging utilizing CR and DR. Similarly, fluoroscopy has progressed by directly viewing image intensifiers in darkened rooms to modern flat panel image receptor systems utilizing pulsed radiation, automated variable filtration, and digitally processed images. Mammography is one of the most highly optimized imaging procedures performed, because it is a repetitive screening procedure that results in annual radiation exposure. Mammography is also the only imaging procedure in the United States in which the radiation dose is regulated by the federal government. Consequently, many medical physicists have studied the dosimetry associated with screen-film and digital mammography. In this review, a brief history of mammography dose assessment by medical physicists is discussed. CT was introduced into clinical practice in the early 1970s, and has grown into one of the most important modalities available for diagnostic imaging. CT dose quantities and measurement techniques are described, and values of radiation dose for different types of scanner are presented. Organ and effective doses to adult patients are surveyed from the earliest single slice scanners, to the latest versions that include up to two x-ray tubes and can incorporate as many as 256 detector channels. An overview is provided of doses received by pediatric patients undergoing CT examinations, as well as methods, and results, of studies performed to assess the radiation absorbed by the conceptus of pregnant patients.
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Affiliation(s)
- Walter Huda
- Department of Radiology, Medical University of South Carolina, Charleston, South Carolina 29425-3230, USA.
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Li X, Samei E, Segars WP, Sturgeon GM, Colsher JG, Frush DP. Patient-specific dose estimation for pediatric chest CT. Med Phys 2009; 35:5821-8. [PMID: 19175138 DOI: 10.1118/1.3026593] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Current methods for organ and effective dose estimations in pediatric CT are largely patient generic. Physical phantoms and computer models have only been developed for standard/limited patient sizes at discrete ages (e.g., 0, 1, 5, 10, 15 years old) and do not reflect the variability of patient anatomy and body habitus within the same size/age group. In this investigation, full-body computer models of seven pediatric patients in the same size/protocol group (weight: 11.9-18.2 kg) were created based on the patients' actual multi-detector array CT (MDCT) data. Organs and structures in the scan coverage were individually segmented. Other organs and structures were created by morphing existing adult models (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. Organ and effective dose of these patients from a chest MDCT scan protocol (64 slice LightSpeed VCT scanner, 120 kVp, 70 or 75 mA, 0.4 s gantry rotation period, pitch of 1.375, 20 mm beam collimation, and small body scan field-of-view) was calculated using a Monte Carlo program previously developed and validated to simulate radiation transport in the same CT system. The seven patients had normalized effective dose of 3.7-5.3 mSv/100 mAs (coefficient of variation: 10.8%). Normalized lung dose and heart dose were 10.4-12.6 mGy/100 mAs and 11.2-13.3 mGy/100 mAs, respectively. Organ dose variations across the patients were generally small for large organs in the scan coverage (<7%), but large for small organs in the scan coverage (9%-18%) and for partially or indirectly exposed organs (11%-77%). Normalized effective dose correlated weakly with body weight (correlation coefficient: r=-0.80). Normalized lung dose and heart dose correlated strongly with mid-chest equivalent diameter (lung: r=-0.99, heart: r=-0.93); these strong correlation relationships can be used to estimate patient-specific organ dose for any other patient in the same size/protocol group who undergoes the chest scan. In summary, this work reported the first assessment of dose variations across pediatric CT patients in the same size/protocol group due to the variability of patient anatomy and body habitus and provided a previously unavailable method for patient-specific organ dose estimation, which will help in assessing patient risk and optimizing dose reduction strategies, including the development of scan protocols.
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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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