Objective: We aimed to estimate the risks of radiation exposure from a single head CT scan to children of different ages. Materials and Methods: We constructed a multistate time-dependent Markov model to simulate the course of children exposed to a head CT. The relevant literature was reviewed for probabilities, which were used to calculate tumor types, latencies after exposure and outcomes in the model. Where multiple approximations of the same probability had been reported, meta-analytic techniques were employed to compute pooled estimates. The model was then used to calculate the effect of the radiation exposure on life expectancy and quality of life for children following head CT at different ages. Results: The tumors likely to be induced by low-level cranial irradiation include thyroid carcinoma (47%), meningioma (34%) and glioma (19%). According to the model, a single head CT is likely to cause one of these tumors in 0.22% of 1-year-olds, 30% of whom will consequently die. The exposure will shorten the life expectancy of all exposed 1-year-olds by an average of 0.04 years and their expected quality of life by 0.02 quality-adjusted life years. The risks of radiation exposure diminish for older children. Conclusions: The model predicts that the effective radiation dose from a single head CT is capable of inducing a thyroid or brain tumor in an infant or child. These tumors can severely impact both quality of life and life expectancy. Care should be taken before ordering CT scans in children, particularly in infants and toddlers.

Keywords:
Cranial CT scan, Radiation-induced tumor, Thyroid carcinoma, Meningioma, Glioblastoma multiforme, Astrocytoma
1.
Committee to Assess Health Risks from Exposure to Low Levels of Ionizing Radiation NRC: Health Risks from Exposure to Low Levels of Ionizing Radiation: BEIR VII Phase 2. Washington, National Academies Press, 2005.
2.
Khursheed A, Hillier MC, Shrimpton PC, Wall BF: Influence of patient age on normalized effective doses calculated for CT examinations. Br J Radiol 2002;75:819–830.
3.
Theocharopoulos N, Damilakis J, Perisinakis K, Tzedakis A, Karantanas A, Gourtsoyiannis N: Estimation of effective doses to adult and pediatric patients from multislice computed tomography: a method based on energy imparted. Med Phys 2006;33:3846–3856.
4.
Vock P: CT dose reduction in children. Eur Radiol 2005;15:2330–2340.
5.
Huda W, Vance A: Patient radiation doses from adult and pediatric CT. AJR Am J Roentgenol 2007;188:540–546.
6.
McCollough CH, Schueler BA: Calculation of effective dose. Med Phys 2000;27:828–837.
7.
Anonymous: 1990 Recommendations of the International Commission on Radiological Protection. New York, International Commission on Radiological Protection, 1990, No 1–3.
8.
American Academy of Pediatrics, Committee on Environmental Health: Risk of ionizing radiation exposure to children: a subject review. Pediatrics 1998;101:717–719.
9.
Frush DP, Donnelly LF, Rosen NS: Computed tomography and radiation risks: what pediatric health care providers should know. Pediatrics 2003;112:951–957.
10.
National Research Council Committee on the Biological Effects of Ionizing Radiation: Health Effects of Exposure to Low Levels of Ionizing Radiation. Washington, National Academy Press, 1990.
11.
Wilson-Costello D, Rao PS, Morrison S, Hack M: Radiation exposure from diagnostic radiographs in extremely low birth weight infants. Pediatrics 1996;97:369–374.
12.
Brenner D, Elliston C, Hall E, Berdon W: Estimated risks of radiation-induced fatal cancer from pediatric CT. AJR Am J Roentgenol 2001;176:289–296.
13.
Durham SR, Liu KC, Selden NR: Utility of serial computed tomography imaging in pediatric patients with head trauma. J Neurosurg 2006;105(suppl 5):365–369.
14.
Herbert M: Issues in minor head injury: to CT or not to CT, that is the question. Emerg Radiol 2000;7:7–13.
15.
Huda W, Chamberlain CC, Rosenbaum AE, Garrisi W: Radiation doses to infants and adults undergoing head CT examinations. Med Phys 2001;28:393–399.
16.
Macgregor DM, McKie L: CT or not CT – that is the question: Whether ’tis better to evaluate clinically and x ray than to undertake a CT head scan! Emerg Med J 2005;22:541–543.
17.
Thierry-Chef I, Simon SL, Miller DL: Radiation dose and cancer risk among pediatric patients undergoing interventional neuroradiology procedures. Pediatr Radiol 2006;36(suppl 14):159–162.
18.
Brenner DJ, Hall EJ: Computed tomography – an increasing source of radiation exposure. N Engl J Med 2007;357:2277–2284.
19.
Pages J, Buls N, Osteaux M: CT doses in children: a multicentre study. Br J Radiol 2003;76:803–811.
20.
National Institute for Clinical Excellence: Head injury triage, assessment, investigation and early management of head injury in infants, children and adults. London, National Institute for Clinical Excellence, 2003. http://www.nice.org.uk/page.aspx?o=56817 (accessed June 6, 2007).
21.
Mettler FA Jr, Wiest PW, Locken JA, Kelsey CA: CT scanning: patterns of use and dose. J Radiol Prot 2000;20:353–359.
22.
Paterson A, Frush DP: Dose reduction in paediatric MDCT: general principles. Clin Radiol 2007;62:507–517.
23.
Lee CI, Haims AH, Monico EP, Brink JA, Forman HP: Diagnostic CT scans: assessment of patient, physician, and radiologist awareness of radiation dose and possible risks. Radiology 2004;231:393–398.
24.
Rogers LF: Taking care of children: check out the parameters used for helical CT. AJR Am J Roentgenol 2001;176:287.
25.
Donnelly LF, Frush DP: Fallout from recent articles on radiation dose and pediatric CT. Pediatr Radiol 2001;31:388; discussion 389–391.
26.
Huda W, Lieberman KA, Chang J, Roskopf ML: Patient size and x-ray technique factors in head computed tomography examinations. I. Radiation doses. Med Phys 2004;31:588–594.
27.
Brenner DJ: Estimating cancer risks from pediatric CT: going from the qualitative to the quantitative. Pediatr Radiol 2002;32:228–233; discussion 242–244.
28.
Ron E, Modan B, Boice JD Jr, et al: Tumors of the brain and nervous system after radiotherapy in childhood. N Engl J Med 1988;319:1033–1039.
29.
Sadetzki S, Chetrit A, Freedman L, Stovall M, Modan B, Novikov I: Long-term follow-up for brain tumor development after childhood exposure to ionizing radiation for tinea capitis. Radiat Res 2005;163:424–432.
30.
Sadetzki S, Chetrit A, Lubina A, Stovall M, Novikov I: Risk of thyroid cancer after childhood exposure to ionizing radiation for tinea capitis. J Clin Endocrinol Metab 2006;91:4798–4804.
31.
Sadetzki S, Flint-Richter P, Ben-Tal T, Nass D: Radiation-induced meningioma: a descriptive study of 253 cases. J Neurosurg 2002;97:1078–1082.
32.
Preston DL, Ron E, Yonehara S, et al: Tumors of the nervous system and pituitary gland associated with atomic bomb radiation exposure. J Natl Cancer Inst 2002;94:1555–1563.
33.
Yonehara S, Brenner AV, Kishikawa M, et al: Clinical and epidemiologic characteristics of first primary tumors of the central nervous system and related organs among atomic bomb survivors in Hiroshima and Nagasaki, 1958–1995. Cancer 2004;101:1644–1654.
34.
Steliarova-Foucher E, Stiller CA, Pukkala E, Lacour B, Plesko I, Parkin DM: Thyroid cancer incidence and survival among European children and adolescents (1978–1997): report from the Automated Childhood Cancer Information System project. Eur J Cancer 2006;42:2150–2169.
35.
De Vathaire F, Hardiman C, Shamsaldin A, et al: Thyroid carcinomas after irradiation for a first cancer during childhood. Arch Intern Med 1999;159:2713–2719.
36.
Ron E, Lubin JH, Shore RE, et al: Thyroid cancer after exposure to external radiation: a pooled analysis of seven studies. Radiat Res 1995;141:259–277.
37.
Musa BS, Pople IK, Cummins BH: Intracranial meningiomas following irradiation – a growing problem? Br J Neurosurg 1995;9:629–637.
38.
Pollak L, Walach N, Gur R, Schiffer J: Meningiomas after radiotherapy for tinea capitis – still no history. Tumori 1998;84:65–68.
39.
Liwnicz BH, Berger TS, Liwnicz RG, Aron BS: Radiation-associated gliomas: a report of four cases and analysis of postradiation tumors of the central nervous system. Neurosurgery 1985;17:436–445.
40.
McIver JI, Pollock BE: Radiation-induced tumor after stereotactic radiosurgery and whole brain radiotherapy: case report and literature review. J Neurooncol 2004;66: 301–305.
41.
Minniti G, Traish D, Ashley S, Gonsalves A, Brada M: Risk of second brain tumor after conservative surgery and radiotherapy for pituitary adenoma: update after an additional 10 years. J Clin Endocrinol Metab 2005;90:800–804.
42.
Neglia JP, Robison LL, Stovall M, et al: New primary neoplasms of the central nervous system in survivors of childhood cancer: a report from the Childhood Cancer Survivor Study. J Natl Cancer Inst 2006;98:1528–1537.
43.
Salvati M, Frati A, Russo N, et al: Radiation-induced gliomas: report of 10 cases and review of the literature. Surg Neurol 2003;60:60–67; discussion 67.
44.
Simmons NE, Laws ER Jr: Glioma occurrence after sellar irradiation: case report and review. Neurosurgery 1998;42:172–178.
45.
Arias E: United States Life Tables, 2001. Natl Vital Stat Rep 2004;52:1–38.
46.
King JT Jr, Berlin JA, Flamm ES: Morbidity and mortality from elective surgery for asymptomatic, unruptured, intracranial aneurysms: a meta-analysis. J Neurosurg 1994;81:837–842.
47.
Einarson TR: Pharmacoeconomic applications of meta-analysis for single groups using antifungal onychomycosis lacquers as an example. Clin Ther 1997;19:559–569; discussion 538–539.
48.
Gold M, Siegel J, Russell L, Weinstein M: Cost-Effectiveness in Health and Medicine. New York, Oxford University Press, 1996.
49.
Sonnenberg FA, Beck JR: Markov models in medical decision making: a practical guide. Med Decis Making 1993;13:322–338.
50.
Salvati M, Artico M, Caruso R, Rocchi G, Orlando ER, Nucci F: A report on radiation-induced gliomas. Cancer 1991;67:392–397.
51.
Colonna M, Grande E, Jonasson JG, Eurocare Working G: Variation in relative survival of thyroid cancers in Europe: results from the analysis on 21 countries over the period 1983–1994 (EUROCARE-3 study). Eur J Cancer 2006;42:2598–2608.
52.
Roman S, Lin R, Sosa JA: Prognosis of medullary thyroid carcinoma: demographic, clinical, and pathologic predictors of survival in 1252 cases. Cancer 2006;107:2134–2142.
53.
Curry WT, McDermott MW, Carter BS, Barker FG 2nd: Craniotomy for meningioma in the United States between 1988 and 2000: decreasing rate of mortality and the effect of provider caseload. J Neurosurg 2005;102:977–986.
54.
Condra KS, Buatti JM, Mendenhall WM, Friedman WA, Marcus RB Jr, Rhoton AL: Benign meningiomas: primary treatment selection affects survival. Int J Radiat Oncol Biol Phys 1997;39:427–436.
55.
Helseth A: Incidence and survival of intracranial meningioma patients in Norway 1963–1992. Neuroepidemiology 1997;16:53–59.
56.
McCarthy BJ, Davis FG, Freels S, et al: Factors associated with survival in patients with meningioma. J Neurosurg 1998;88:831–839.
57.
Mihaila D, Jankowski M, Gutierrez JA, et al: Meningiomas: loss of heterozygosity on chromosome 10 and marker-specific correlations with grade, recurrence, and survival. Clin Cancer Res 2003;9:4443–4451.
58.
Sankila R, Kallio M, Jaaskelainen J, Hakulinen T. Long-term survival of 1986 patients with intracranial meningioma diagnosed from 1953 to 1984 in Finland: comparison of the observed and expected survival rates in a population-based series. Cancer 1992;70:1568–1576.
59.
Bohinski RJ, Kokkino AK, Warnick RE, et al: Glioma resection in a shared-resource magnetic resonance operating room after optimal image-guided frameless stereotactic resection. Neurosurgery 2001;48:731–742; discussion 742–744.
60.
Brell M, Ibanez J, Caral L, Ferrer E: Factors influencing surgical complications of intra-axial brain tumours. Acta Neurochir (Wien) 2000;142:739–750.
61.
Chang SM, Parney IF, McDermott M, et al: Perioperative complications and neurological outcomes of first and second craniotomies among patients enrolled in the Glioma Outcome Project. J Neurosurg 2003;98:1175–1181.
62.
Devaux BC, O’Fallon JR, Kelly PJ: Resection, biopsy, and survival in malignant glial neoplasms: a retrospective study of clinical parameters, therapy, and outcome. J Neurosurg 1993;78:767–775.
63.
Sawaya R, Hammoud M, Schoppa D, et al: Neurosurgical outcomes in a modern series of 400 craniotomies for treatment of parenchymal tumors. Neurosurgery 1998;42:1044–1055; discussion 1055–1056.
64.
Taylor MD, Bernstein M: Awake craniotomy with brain mapping as the routine surgical approach to treating patients with supratentorial intraaxial tumors: a prospective trial of 200 cases. J Neurosurg 1999;90:35–41.
65.
Vorster SJ, Barnett GH: A proposed preoperative grading scheme to assess risk for surgical resection of primary and secondary intraaxial supratentorial brain tumors. Neurosurg Focus 1998;4:e2.
66.
Abdulrauf SI, Edvardsen K, Ho KL, Yang XY, Rock JP, Rosenblum ML: Vascular endothelial growth factor expression and vascular density as prognostic markers of survival in patients with low-grade astrocytoma. J Neurosurg 1998;88:513–520.
67.
Arienti VM, Botturi A, Boiardi A, et al: Adult brain low-grade astrocytomas: survival after surgery and radiotherapy. Neurol Sci 2001;22:233–238.
68.
Magrini SM, Ricardi U, Santoni R, et al: Patterns of practice and survival in a retrospective analysis of 1722 adult astrocytoma patients treated between 1985 and 2001 in 12 Italian radiation oncology centers. Int J Radiat Oncol Biol Phys 2006;65:788–799.
69.
Ohgaki H, Kleihues P: Population-based studies on incidence, survival rates, and genetic alterations in astrocytic and oligodendroglial gliomas. J Neuropathol Exp Neurol 2005;64:479–489.
70.
Pallud J, Mandonnet E, Duffau H, et al: Prognostic value of initial magnetic resonance imaging growth rates for World Health Organization grade II gliomas. Ann Neurol 2006;60:380–383.
71.
Shinoda J, Sakai N, Nakatani K, Funakoshi T: Prognostic factors in supratentorial WHO grade II astrocytoma in adults. Br J Neurosurg 1998;12:318–324.
72.
Wessels PH, Hopman AH, Kubat B, et al: Proliferation and aneusomy predict survival of young patients with astrocytoma grade II. Br J Cancer 2003;89:128–134.
73.
Brandes AA, Nicolardi L, Tosoni A, et al: Survival following adjuvant PCV or temozolomide for anaplastic astrocytoma. Neuro Oncol 2006;8:253–260.
74.
Diete S, Treuheit T, Dietzmann K, Schmidt U, Wallesch CW: Sex differences in length of survival with malignant astrocytoma, but not with glioblastoma. J Neurooncol 2001;53:47–49.
75.
Laws ER, Parney IF, Huang W, et al: Survival following surgery and prognostic factors for recently diagnosed malignant glioma: data from the Glioma Outcomes Project. J Neurosurg 2003;99:467–473.
76.
Leenstra S, Oskam NT, Bijleveld EH, Bosch DA, Troost D, Hulsebos TJ: Genetic sub-types of human malignant astrocytoma correlate with survival. Int J Cancer 1998;79:159–165.
77.
Li X, Jin H, Lu Y, Oh J, Chang S, Nelson SJ: Identification of MRI and 1H MRSI parameters that may predict survival for patients with malignant gliomas. NMR Biomed 2004;17:10–20.
78.
Lin CL, Lieu AS, Lee KS, et al: The conditional probabilities of survival in patients with anaplastic astrocytoma or glioblastoma multiforme. Surg Neurol 2003;60:402–406; discussion 406.
79.
Beauchesne P, Pedeux R, Boniol M, Soler C: 99mTc-sestamibi brain SPECT after chemoradiotherapy is prognostic of survival in patients with high-grade glioma. J Nucl Med 2004;45:409–413.
80.
Polin RS, Marko NF, Ammerman MD, et al: Functional outcomes and survival in patients with high-grade gliomas in dominant and nondominant hemispheres. J Neurosurg 2005;102:276–283.
81.
Burnet NG, Jena R, Jefferies SJ, Stenning SP, Kirkby NF: Mathematical modelling of survival of glioblastoma patients suggests a role for radiotherapy dose escalation and predicts poorer outcome after delay to start treatment. Clin Oncol (R Coll Radiol) 2006;18:93–103.
82.
Korkolopoulou P, Patsouris E, Konstantinidou AE, et al: Mitosin and DNA topoisomerase IIalpha: two novel proliferation markers in the prognostication of diffuse astrocytoma patient survival. Appl Immunohistochem Mol Morphol 2001;9:207–214.
83.
Stark AM, Hedderich J, Held-Feindt J, Mehdorn HM: Glioblastoma – the consequences of advanced patient age on treatment and survival. Neurosurg Rev 2007;30:56–61; discussion 61–62.
84.
Ushio Y, Kochi M, Hamada J, Kai Y, Nakamura H: Effect of surgical removal on survival and quality of life in patients with supratentorial glioblastoma. Neurol Med Chir (Tokyo) 2005;45:454–460; discussion 460–461.
85.
Wang L, Wei Q, Wang LE, et al: Survival prediction in patients with glioblastoma multiforme by human telomerase genetic variation. J Clin Oncol 2006;24:1627–1632.
86.
Yuile P, Dent O, Cook R, Biggs M, Little N: Survival of glioblastoma patients related to presenting symptoms, brain site and treatment variables. J Clin Neurosci 2006;13:747–751.
87.
Mernagh P, Campbell S, Dietlein M, Luster M, Mazzaferri E, Weston AR: Cost-effectiveness of using recombinant human TSH prior to radioiodine ablation for thyroid cancer, compared with treating patients in a hypothyroid state: the German perspective. Eur J Endocrinol 2006;155:405–414.
88.
Shah MD, Witterick IJ, Eski SJ, Pinto R, Freeman JL: Quality of life in patients undergoing thyroid surgery. J Otolaryngol 2006;35:209–215.
89.
Tagay S, Herpertz S, Langkafel M, et al: Health-related quality of life, anxiety and depression in thyroid cancer patients under short-term hypothyroidism and TSH-suppressive levothyroxine treatment. Eur J Endocrinol 2005;153:755–763.
90.
Chow SM, Au KH, Choy TS, et al: Health-related quality-of-life study in patients with carcinoma of the thyroid after thyroxine withdrawal for whole body scanning. Laryngoscope 2006;116:2060–2066.
91.
Kung S, Rummans TA, Colligan RC, et al: Association of optimism-pessimism with quality of life in patients with head and neck and thyroid cancers. Mayo Clin Proc 2006;81:1545–1552.
92.
Tagay S, Herpertz S, Langkafel M, et al: Health-related quality of life, depression and anxiety in thyroid cancer patients. Qual Life Res 2006;15:695–703.
93.
Bhat SR, Goodwin TL, Burwinkle TM, et al: Profile of daily life in children with brain tumors: an assessment of health-related quality of life. J Clin Oncol 2005;23:5493–5500.
94.
Shaw EG, Rosdhal R, D’Agostino RB Jr, et al: Phase II study of donepezil in irradiated brain tumor patients: effect on cognitive function, mood, and quality of life. J Clin Oncol 2006;24:1415–1420.
95.
Kalkanis SN, Quinones-Hinojosa A, Buzney E, Ribaudo HJ, Black PM: Quality of life following surgery for intracranial meningiomas at Brigham and Women’s Hospital: a study of 164 patients using a modification of the functional assessment of cancer therapy-brain questionnaire. J Neurooncol 2000;48:233–241.
96.
Mohsenipour I, Deusch E, Gabl M, Hofer M, Twerdy K: Quality of life in patients after meningioma resection. Acta Neurochir (Wien) 2001;143:547–553.
97.
Salo J, Niemela A, Joukamaa M, Koivukangas J: Effect of brain tumour laterality on patients’ perceived quality of life. J Neurol Neurosurg Psychiatry 2002;72:373–377.
98.
Eiser C, Eiser JR, Stride CB: Quality of life in children newly diagnosed with cancer and their mothers. Health Qual Life Outcomes 2005;3:29.
99.
Kennedy CR, Leyland K: Comparison of screening instruments for disability and emotional/behavioral disorders with a generic measure of health-related quality of life in survivors of childhood brain tumors. Int J Cancer Suppl 1999;12:106–111.
100.
Meeske K, Katz ER, Palmer SN, Burwinkle T, Varni JW: Parent proxy-reported health-related quality of life and fatigue in pediatric patients diagnosed with brain tumors and acute lymphoblastic leukemia. Cancer 2004;101:2116–2125.
101.
Barr RD, Simpson T, Whitton A, Rush B, Furlong W, Feeny DH: Health-related quality of life in survivors of tumours of the central nervous system in childhood – a preference-based approach to measurement in a cross-sectional study. Eur J Cancer 1999;35:248–255.
102.
Brown PD, Maurer MJ, Rummans TA, et al: A prospective study of quality of life in adults with newly diagnosed high-grade gliomas: the impact of the extent of resection on quality of life and survival. Neurosurgery 2005;57:495–504.
103.
Cardarelli C, Cereda C, Masiero L, et al: Evaluation of health status and health-related quality of life in a cohort of Italian children following treatment for a primary brain tumor. Pediatr Blood Cancer 2006;46:637–644.
104.
Foreman NK, Faestel PM, Pearson J, et al: Health status in 52 long-term survivors of pediatric brain tumors. J Neurooncol 1999;41:47–53.
105.
Glaser A, Kennedy C, Punt J, Walker D: Standardized quantitative assessment of brain tumor survivors treated within clinical trials in childhood. Int J Cancer Suppl 1999;12:77–82.
106.
Odame I, Duckworth J, Talsma D, et al: Osteopenia, physical activity and health-related quality of life in survivors of brain tumors treated in childhood. Pediatr Blood Cancer 2006;46:357–362.
107.
Hamilton DA: Adding concomitant and adjuvant temozolomide to radiotherapy does not reduce health-related quality of life in people with glioblastoma. Cancer Treat Rev 2006;32:483–486.
108.
Taphoorn MJ, Stupp R, Coens C, et al: Health-related quality of life in patients with glioblastoma: a randomised controlled trial. Lancet Oncol 2005;6:937–944.
109.
Giovagnoli AR, Silvani A, Colombo E, Boiardi A: Facets and determinants of quality of life in patients with recurrent high grade glioma. J Neurol Neurosurg Psychiatry 2005;76:562–568.
110.
Maddrey AM, Bergeron JA, Lombardo ER, et al: Neuropsychological performance and quality of life of 10 year survivors of childhood medulloblastoma. J Neurooncol 2005;72:245–253.
111.
Ribi K, Relly C, Landolt MA, Alber FD, Boltshauser E, Grotzer MA: Outcome of medulloblastoma in children: long-term complications and quality of life. Neuropediatrics 2005;36:357–365.
112.
Zorc JJ, Krugman SD, Ogborn J, Benson J: Radiographic evaluation for suspected cerebrospinal fluid shunt obstruction. Pediatr Emerg Care 2002;18:337–340.
113.
Cohnen M, Fischer H, Hamacher J, Lins E, Kotter R, Modder U: CT of the head by use of reduced current and kilovoltage: relationship between image quality and dose reduction. AJNR Am J Neuroradiol 2000;21:1654–1660.
114.
Huda W, Lieberman KA, Chang J, Roskopf ML: Patient size and x-ray technique factors in head computed tomography examinations. II. Image quality. Med Phys 2004;31:595–601.
115.
Mayo JR, Kim KI, MacDonald SL, et al: Reduced radiation dose helical chest CT: effect on reader evaluation of structures and lung findings. Radiology 2004;232:749–756.
116.
Siegel MJ, Schmidt B, Bradley D, Suess C, Hildebolt C: Radiation dose and image quality in pediatric CT: effect of technical factors and phantom size and shape. Radiology 2004;233:515–522.
117.
Tzedakis A, Perisinakis K, Raissaki M, Damilakis J: The effect of z overscanning on radiation burden of pediatric patients undergoing head CT with multidetector scanners: a Monte Carlo study. Med Phys 2006;33:2472–2478.
118.
Donnelly LF: Reducing radiation dose associated with pediatric CT by decreasing unnecessary examinations. AJR Am J Roentgenol 2005;184:655–657.
119.
Li J, Udayasankar UK, Toth TL, Seamans J, Small WC, Kalra MK: Automatic patient centering for MDCT: effect on radiation dose. AJR Am J Roentgenol 2007;188:547–552.
120.
Slovis TL: Children, computed tomography radiation dose, and the As Low As Reasonably Achievable (ALARA) concept. Pediatrics 2003;112:971–972.
121.
Semelka RC, Armao DM, Elias J Jr, Huda W: Imaging strategies to reduce the risk of radiation in CT studies, including selective substitution with MRI. J Magn Reson Imaging 2007;25:900–909.
122.
Nishizawa K, Maruyama T, Takayama M, Okada M, Hachiya J, Furuya Y: Determinations of organ doses and effective dose equivalents from computed tomographic examination. Br J Radiol 1991;64:20–28.
123.
Giles J: Study warns of ‘avoidable’ risks of CT scans. Nature 2004;431:391.
© 2008 S. Karger AG, Basel
2008
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.