| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1
Center for Radiological Research, Columbia University, 630 W. 168th St., New
York, NY 10032.
2
Department of Radiology, Division of Pediatric Radiology,
Columbia-Presbyterian Medical Center, 630 W. 168th St., New York, NY
10032.
Received March 2, 2000;
accepted after revision July 12, 2000.
Supported in part by grant DE-FG02-98ER62686 from the United States
Department of Energy and by grant CA-77285 from the National Cancer
Institute.
Abstract
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
MATERIALS AND METHODS. Organ doses as a function of age-at-diagnosis were estimated for common CT examinations, and estimated attributable lifetime cancer mortality risks (per unit dose) for different organ sites were applied. Standard models that assume a linear extrapolation of risks from intermediate to low doses were applied. On the basis of current standard practice, the same exposures (milliampere-seconds) were assumed, independent of age.
RESULTS. The larger doses and increased lifetime radiation risks in children produce a sharp increase, relative to adults, in estimated risk from CT. Estimated lifetime cancer mortality risks attributable to the radiation exposure from a CT in a 1-year-old are 0.18% (abdominal) and 0.07% (head)—an order of magnitude higher than for adults—although those figures still represent a small increase in cancer mortality over the natrual background rate. In the United States, of approximately 600,000 abdominal and head CT examinations annually performed in children under the age of 15 years, a rough estimate is that 500 of these individuals might ultimately die from cancer attributable to the CT radiation.
CONCLUSION. The best available risk estimates suggest that pediatric CT will result in significantly increased lifetime radiation risk over adult CT, both because of the increased dose per milliampere-second, and the increased lifetime risk per unit dose. Lower milliampere-second settings can be used for children without significant loss of information. Although the risk—benefit balance is still strongly tilted toward benefit, because the frequency of pediatric CT examinations is rapidly increasing, estimates that quantitative lifetime radiation risks for children undergoing CT are not negligible may stimulate more active reduction of CT exposure settings in pediatric patients.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Figure 1 shows a breakdown of the number of CT examinations by age at examination, based on the results of a 1989 British survey [5]; in this survey, approximately 4% of CT examinations (which corresponds to about 106/year in the United States) were performed on children under the age of 15 years. The proportion of childhood CT examinations is rapidly increasing (indeed, an average value of 6% was estimated in 1993 [6]); for example, Coren et al. [7] reported a 63% increase in requests for pediatric CT between 1991 and 1994.
|
The recent increase in pediatric CT examinations is particularly marked in the United States. Figure 2 shows the number of abdominal and pelvic CT examinations of children under a given age at a major American children's hospital for 1996 through 1999. This figure shows, for example, a 92% increase between 1996 and 1999 in abdominal and pelvic CT examinations on children less than 15 years old. The increased frequency of pediatric CT, particularly in the United States, is largely caused by the advent of fast helical CT [1], which reduces the need for sedation [8]. Helical CT makes more types of CT examinations, particularly evaluation of the acute pediatric abdomen [9, 10], more practical in younger, sicker, or less cooperative children [1]; it also allows newer pediatric CT applications such as dynamic studies of pulmonary physiology and three-dimensional airway imaging.
|
Pediatrics represents a comparatively small, though increasing, fraction of the overall number of CT examinations. However, we show here that the combination of higher radiation doses to children for a given CT examination and, more importantly, the much larger lifetime risks per unit dose of radiation that apply to children, result in lifetime cancer mortality attributable to the radiation exposure from CT that is significantly higher in children than in adults.
A central issue is that epidemiologic evidence [11] points strongly to a "relative" risk mechanism for radiation-induced cancer; essentially, that the excess probability of cancer mortality after radiation exposure is proportional to the natural background rate of cancer death. In other words, the pattern of excess risk is that of a lifelong elevation (though not necessarily a fixed elevation) of the "natural" age-specific risk. Lifetime radiation risk estimation, both for the analysis of atomic bomb survivor data [11] and for generating resultant risk estimates for Western populations [12, 13], has used relative risk models. The implication of a relative risk mechanism is that the lifetime risk attributable to a single small dose of radiation at a given age is larger for children (who face a large lifetime background risk of cancer mortality) but decreases with age (Fig. 3). This larger attributable lifetime risk after childhood exposure implies that a given radiation dose to a child is of greater public health significance than the same dose in an adult.
|
Although some estimates have been made of cancer risks to adults attributable to the radiation from CT examinations [14, 15], no such estimates have been made for children. We use here calculated organ doses from CT examinations in combination with age-at-exposure—dependent estimates of attributable lifetime risks per unit dose to provide estimates of the lifetime age-dependent cancer mortality risks associated with common CT examinations.
As we discuss, various uncertainties are associated with these risk estimates, both in terms of the dose for a given CT examination and in terms of the cancer risk per unit dose. However, neither the uncertainties in the doses nor the uncertainties in the risks per unit dose are such that the overall pattern of risks for children relative to adults—a significantly larger lifetime cancer mortality risk associated with pediatric CT—is likely to change.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
As discussed in the following text, because of the inhomogeneous nature of the dose distribution produced by CT, we need to evaluate the age-dependent risks separately for each group of potential cancer sites. Figure 4A,4B shows these age-dependent lifetime cancer mortality risks derived from the Biological Effects of Ionizing Radiations committee evaluation.
|
|
Overall Methodology
Our basic technique is to multiply age-dependent lifetime cancer mortality
risks (per unit dose) by estimated age-dependent doses produced by various CT
examinations. In fact, the age dependence of the cancer mortality risk varies
considerably from site to site (Fig.
4A,4B).
Thus, for a highly inhomogeneous dose distribution, as produced by a CT
examination, the age dependence of the overall cancer risk cannot be directly
inferred from estimates of the total cancer mortality (for all sites combined)
per unit effective dose. Rather, the age dependence of the risks for the
various groups of sites shown in Figure
4A,4B
are each separately calculated by applying appropriate site-specific doses to
the age- and site-dependent risks in Figure
4A,4B,
and these site-specific risks are then summed to yield the overall
age-dependent lifetime cancer mortality risk.
Age-Dependent Doses from CT Examinations
For adults, various calculations and measurements are available of the
doses produced by a variety of CT examinations under different conditions
[16,
17], the most comprehensive
being the results of a 1989 survey of CT practice in Britain, in which organ
doses were estimated for 17 CT examinations from more than 100 CT scanners
[16]. For children, however,
less information is available. Doses to specific organs at some ages have been
reported
[18,19,20],
and systematic effective dose (i.e., organ-weighted average body dose)
calculations as a function of age at examination have recently been reported
[21]. Therefore, we chose to
use estimated organ doses for adult CT examinations, and scale them for
children using relative effective doses.
Because of the comprehensive nature of the British survey, we chose to scale adult organ doses as reported in this 1989 survey [16] of CT practice in Britain. These results were averaged over 121 different machines (108 for routine abdominal scans) surveyed at the time. The mean scan parameters, averaged over all the machines surveyed, are 404 mAs, 15.5 slices, and 9.3-mm slice width for routine abdominal CT; and 462 mAs, 12.5 slices, and 9.1-mm slice width for routine head CT. These surveyed exposure settings, reflecting day-to-day practice, are similar to more recent survey results of adult CT in the United States [22] and Norway [23], although probably considerably higher than optimal [24]. As discussed here, all the doses and risks presented vary approximately linearly with exposure (milliampere-seconds), so the results obtained here can easily be scaled to other milliampere-second settings.
To obtain organ doses from pediatric CT examinations, relative changes in effective dose as a function of age, estimated by Huda et al. [21] for head and for abdominal CT examinations, were applied to all these adult organ doses. We assumed that the relative doses to any organ relative to any other organ remain unchanged with age. Typical results are shown in Figure 5A,5B.
|
|
The relative doses as a function of age obtained with this method are in reasonable agreement with the Monte Carlo calculations by Zankl et al. [17, 19], who used computer-simulated anthropomorphic phantoms of a neonate, a 7-year-old, and an adult. For example, the stomach dose from an abdominal CT examination in a 7-year-old relative to that in an adult, as calculated by Zankl et al. [17, 19] was 1.35; using the current methodology, the same relative dose was 1.39.
The specific groupings of potential types of cancer for which evaluated
radiation-induced risks are available are leukemia, digestive organ cancer,
lung cancer, breast cancer (for women), and other cancer
[12]. Digestive organ cancer
includes cancer of the colon, stomach, liver, pancreas, esophagus, and small
intestine; "other" cancer includes brain, thyroid, bladder,
kidney, adrenal gland, spleen, thymus, skin, bone, testes (for men), and
uterus and ovaries (for women). To use the risk data shown in Figure
4A,4B,
doses appropriate to these sites or groups of sites need to be assigned. For
leukemia, lung, and breast cancer in women, doses to the bone marrow, lung,
and female breast were respectively used. For digestive cancer, a weighted
average of the doses to the relevant organs was used, the weighting consisting
of the relative radiation—carcinogenic sensitivities of these organs.
Thus, the dose to the digestive organs was computed as
 | (1) |
 | (2) |
Various authors have suggested that pediatric CT exposures (i.e., milliampere-seconds) could be reduced by 30-50% or more relative to adult exposures to obtain essentially the same information [24,25,26,27,28]. However, most institutions do not reduce the exposure for children or other patients with reduced body weight. For example, Huda et al. [29] measured the correlation between patient weight and applied tube current in patients undergoing thoracic CT examinations and found essentially no correlation (r = 0.06), indicating that those CT examination protocols did not take into account the size of the patient. Similar results have been shown for other CT examinations and at other institutions [30, 31]. Thus, in accordance with current standard practice, we have assumed that the exposure technique (milliampere-seconds) is not reduced for a pediatric relative to an adult CT examination. Of course, a given reduction in exposure for a pediatric CT examination would result in a corresponding reduction in dose and thus in risk.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
|
Breakdowns of the estimated lifetime cancer mortality by sex and by site
are shown in Figure
7A,7B,7C,7D.
For head CT examinations, the estimated "other cancer" mortality
category is dominated by brain cancer, with a small contribution (
10%)
from thyroid cancer. For abdominal CT examinations, the risks are dominated by
digestive organ cancer, primarily stomach, liver, and colon cancer. Overall,
the estimated risks for abdominal CT examinations are significantly greater
than those for head examinations, primarily because of the larger combined
lifetime mortality risks (per unit dose) for exposure of the digestive organs
relative to exposure of the brain and thyroid.
|
|
|
|
Estimated lifetime cancer mortality risks from abdominal CT examinations are somewhat greater for women than for men, an effect that is caused by the significantly greater estimated risks per unit dose for digestive organ cancer in women (Fig. 4A,4B). The sex effect for head examinations is smaller because estimated brain tumor risks do not vary greatly with sex. The estimated risk for abdominal CT examinations decreases much more slowly with increasing age at examination than does the risk from head examinations, an effect caused by the near constancy of the estimated lifetime risk (per unit dose) for digestive organ cancer from birth to approximately 25 years old.
To generate an estimate of the absolute numbers of cancer deaths attributable to CT examinations, we first applied the 1995 United States rate of CT examinations (91/1000 population per year) to the current United States population; second, we subdivided this rate, assuming that 40% of CT examinations are of the head and 20% are abdominal [32]; third, we further subdivided this rate into 5-year age-at-examination intervals, assuming the age distribution for CT examinations from the 1989 British survey [5]; and finally, we applied lifetime mortality risks as a function of age at CT, as calculated here.
On the basis of these assumptions, the predicted total number of deaths attributable to 1 (current) year of CT examinations in the United States is approximately 700 from head examinations and approximately 1800 from abdominal examinations, of which approximately 170 and 310, respectively, would be attributable to head and abdominal CT examinations in individuals who were less than 15 years at the time of examination. In both cases, childhood CT examinations contribute significantly to the overall estimated CT-related potential cancer mortality. For example, although CT examinations of patients less than 15 years old contribute only approximately 4% by number, based on our calculations they are estimated to contribute approximately 20% of the total potential cancer mortality from CT examinations.
Again, the doses and risks estimated here depend roughly linearly on the exposure settings assumed. The survey data [16] from which the doses were estimated yielded average exposure settings of 462 mAs for routine head and 404 mAs for routine abdominal CT and, as discussed previously, these values have been used both for adults and for children. Results for any other exposure settings can be simply scaled from these numbers, so that, for example, if the milliampere-second settings were reduced by 40% for pediatric examinations, all the corresponding pediatric risk estimates would also be reduced by 40%.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
For the two routine CT examinations considered here—abdominal and head—the dominant predicted induced malignancies are, respectively, of the digestive organs and of the brain. Although the brain was once considered a comparatively radioresistant organ, more recent data suggest that it is significantly radiosensitive, particularly at very low doses, with the risk increasing with decreasing age [33]. The risk estimates given here are for lifetime cancer mortality; estimated cancer risks from pediatric CT examinations would, by definition, be larger, particularly for CT examinations of the head, because of the larger contribution of radiation-induced thyroid cancer [34].
Although the absolute estimated risks that we have projected are quite
high, the percentage increase in the cancer mortality rate over the natural
background rate is very low. For example, of the approximately 600,000
children less than 15 years old who are estimated to undergo CT each year in
the United States, approximately 140,000 will ultimately die of cancer. Thus,
the estimated projected 500 CT-related deaths represents a small (0.35%)
percentage increase over this background. This small estimated relative risk
suggests that detection of an increased risk in an epidemiologic study would
not be easy, although a recent case-control study
[35] on the association
between pediatric radiologic examination and childhood leukemia did show a
significant elevated risk (linearly related to the number of examinations)
compared with controls in children who received two or more diagnostic
examinations (odds ratio, 1.6; confidence interval, 1.1-2.3).
The CT-related cancer risk estimates provided here are probably the most credible available, but they must be considered with a number of caveats. The most significant caveats relate to the risks per unit dose assumed here (Figs. 3 and 4A,4B) for the comparatively low doses (Fig. 5A,5B) of relevance to a single CT examination. The assumed risk estimates are ultimately derived from analyses of mortality data based on Japanese atomic bomb survivors [11] exposed to intermediate radiation doses. As illustrated in Figure 8, the atomic bomb data provide strong evidence of an increased cancer mortality risk at equivalent doses greater than 100 mSv, good evidence of an increased risk for doses between 50 and 100 mSv, and reasonable evidence for an increased risk for doses between 10 and 50 mSv [11].
|
Some supporting evidence for the risk estimates adopted here at doses of relevance to pediatric CT examinations (Fig. 5A,5B) comes from studies of childhood cancer risks after fetal exposure from diagnostic radiography. In a 1997 review of the data, Doll and Wakeford [36] concluded that doses to the fetus on the order of 10 mSv produce an excess risk of cancer during childhood of roughly 6% per sievert, which would be consistent with the lifetime cancer mortality risks of 14% per sievert used here for an exposed neonate (Fig. 3).
The linear extrapolation without a dose threshold that is used to extrapolate cancer risks to very low doses has been the subject of much debate [37,38,39,40]; however, the main regulatory and advisory groups that have reported on this issue [12, 13, 41, 42] have all concluded that the most scientifically credible approach to risk extrapolation to this dose range is a linear extrapolation from greater doses, which is the assumption implicitly adopted here.
Aside from the correct shape of the dose—risk relationship at low doses, there are further uncertainties in the absolute magnitude of the risks per unit dose shown in Figures 3 and 4A,4B, originating in such issues as dosimetric uncertainties and risk transfer from Japanese to Western populations. An analysis by Sinclair [43] suggested an overall uncertainty in the low—dose total cancer mortality risk estimates (per unit dose) of approximately a factor of 2 (although the uncertainties in cancer risks for individual organs or groups of organs may be larger than this).
The organ dose estimates used in our work also have significant uncertainties attached to them, although these would be expected to be smaller than the uncertainties in the risks per unit dose. Of more importance here are systematic changes in clinical practice, particularly the potential for dose reduction in pediatric CT examinations. Specifically, in line with the standard clinical practice [29,30,31], we have assumed that the same milliampere-second techniques are used for pediatric examinations as for the corresponding adult CT examinations. Several studies have suggested that a technique with significant reduction in exposure (milliampere-seconds) could be adopted for pediatric CT examinations without significant loss of information [25,26,27,28], and any such reduction would yield a corresponding reduction in dose and in risk.
In summary, the following argument suggests that CT exposure settings should be actively reduced when used in a pediatric setting: First, the frequency of pediatric CT examinations is rapidly increasing, largely because of the improved logistics of helical CT. Second, the best available risk estimates suggest that pediatric CT will likely result in significantly increased lifetime risk over adult CT, both because of the increased dose per milliampere-second and because of the increased lifetime risk per unit dose. Third, lower milliampere-second settings can be used for CT examinations of children without significant loss of information.
Specifically, the dose delivered in most pediatric CT examinations could potentially be reduced by reducing the milliampere-seconds either manually [25,26,27,28] or automatically [44] and by increasing the pitch [45]. Various authors [24,25,26,27,28] have suggested that pediatric CT exposures (i.e., milliampere-seconds) could be reduced by at least 30-50% relative to adult exposures to obtain essentially the same information; such reductions would result in a corresponding decrease in radiation risks (whatever they might be) by the same factors.
Of course, in most situations in which pediatric CT is used, the risk—benefit balance is strongly tilted toward benefit [7], which may explain why reduced exposure settings are not routinely used for pediatric CT [29,30,31]. We hope that pointing out that lifetime radiation risks for children undergoing CT are quantitatively not negligible will encourage more active reduction of CT exposure settings in the pediatric context. Both CT equipment manufacturers and pediatric radiologists could contribute to this end.
Acknowledgments
We thank Walter Huda, Paul Shrimpton, Charles Land, Maria Zankl, Bill
McAlister, and Lydia Zablotska for their helpful advice.
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  M. Stevenson Validation of the Pediatric Appendicitis Score AAP Grand Rounds, November 1, 2009; 22(5): 50 - 50. [Full Text] [PDF]
|
|
|
|
 |
|
 K. Bechtel, S. Frasure, C. Marshall, J. Dziura, and C. Simpson Relationship of Serum S100B Levels and Intracranial Injury in Children With Closed Head Trauma Pediatrics, October 1, 2009; 124(4): e697 - e704. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. C. Persaud, M. D. Stevenson, D. R. McMahon, and N. C. Christopher Pediatric Urolithiasis: Clinical Predictors in the Emergency Department Pediatrics, September 1, 2009; 124(3): 888 - 894. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Biswas, J. E. Bible, M. Bohan, A. K. Simpson, P. G. Whang, and J. N. Grauer Radiation Exposure from Musculoskeletal Computerized Tomographic Scans J. Bone Joint Surg. Am., August 1, 2009; 91(8): 1882 - 1889. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Schneebaum, H. Blau, R. Soferman, H. Mussaffi, L. Ben-Sira, M. Schwarz, and Y. Sivan Use and Yield of Chest Computed Tomography in the Diagnostic Evaluation of Pediatric Lung Disease Pediatrics, August 1, 2009; 124(2): 472 - 479. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. H. McCollough, L. Guimaraes, and J. G. Fletcher In Defense of Body CT Am. J. Roentgenol., July 1, 2009; 193(1): 28 - 39. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. M. Lateef, M. Grewal, W. McClintock, J. Chamberlain, H. Kaulas, and K. B. Nelson Headache in Young Children in the Emergency Department: Use of Computed Tomography Pediatrics, July 1, 2009; 124(1): e12 - e17. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Maguire, K. Boutis, E. M. Uleryk, A. Laupacis, and P. C. Parkin Should a Head-Injured Child Receive a Head CT Scan? A Systematic Review of Clinical Prediction Rules Pediatrics, July 1, 2009; 124(1): e145 - e154. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. A. Noah Just a Spoonful of Sugar: Drug Safety for Pediatric Populations J. Law Med. Ethics, June 1, 2009; 37(2): 280 - 291. [PDF]
|
|
|
|
|
|
T. H. Berquist Team work: do we "walk the walk" or just "talk the talk?". Am. J. Roentgenol., May 1, 2009; 192(5): 1165 - 1166. [Full Text] [PDF]
|
|
|
|
|
|
D. I. Bulas, M. J. Goske, K. E. Applegate, and B. P. Wood Image Gently: Why We Should Talk to Parents About CT in Children Am. J. Roentgenol., May 1, 2009; 192(5): 1176 - 1178. [Full Text] [PDF]
|
|
|
|
|
|
L. F. Donnelly, S. M. O'Hara, A. E. Oestreich, L. F. Rogers, and B. G. Brogdon Interaction Between Academic Radiology and the News Media: A Potentially Powerful and Unpredictable Process--Five Stories Am. J. Roentgenol., May 1, 2009; 192(5): 1382 - 1387. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Section on Radiology Diagnostic Imaging of Child Abuse Pediatrics, May 1, 2009; 123(5): 1430 - 1435. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C A Bevan, C S Palmer, J R Sutcliffe, P Rao, S Gibikote, and J Crameri Blunt abdominal trauma in children: how predictive is ALT for liver injury? Emerg. Med. J., April 1, 2009; 26(4): 283 - 288. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. T. Griffey and A. Sodickson Cumulative Radiation Exposure and Cancer Risk Estimates in Emergency Department Patients Undergoing Repeat or Multiple CT Am. J. Roentgenol., April 1, 2009; 192(4): 887 - 892. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Sodickson, P. F. Baeyens, K. P. Andriole, L. M. Prevedello, R. D. Nawfel, R. Hanson, and R. Khorasani Recurrent CT, Cumulative Radiation Exposure, and Associated Radiation-induced Cancer Risks from CT of Adults Radiology, April 1, 2009; 251(1): 175 - 184. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K LEDENIUS, M GUSTAVSSON, S JOHANSSON, F STALHAMMAR, L-M WIKLUND, and A Thilander-KLANG Effect of tube current on diagnostic image quality in paediatric cerebral multidetector CT images Br. J. Radiol., April 1, 2009; 82(976): 313 - 320. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Kim, T. T. Yoshizumi, D. P. Frush, C. Anderson-Evans, and G. Toncheva DOSIMETRIC CHARACTERISATION OF BISMUTH SHIELDS IN CT: MEASUREMENTS AND MONTE CARLO SIMULATIONS Radiat Prot Dosimetry, March 5, 2009; (2009) ncp025v1. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C.B. Nauer, A. Eichenberger, P. Dubach, J. Gralla, and M. Caversaccio CT Radiation Dose for Computer-Assisted Endoscopic Sinus Surgery: Dose Survey and Determination of Dose-Reduction Limits AJNR Am. J. Neuroradiol., March 1, 2009; 30(3): 617 - 622. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. R. Mayo and J. A. Leipsic Radiation Dose in Cardiac CT Am. J. Roentgenol., March 1, 2009; 192(3): 646 - 653. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O J ARTHURS, S J YATES, P A K SET, D A GIBBONS, and A K DIXON Evaluation of image quality and radiation dose in adolescent thoracic imaging: 64-slice is preferable to 16-slice multislice CT Br. J. Radiol., February 1, 2009; 82(974): 157 - 161. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. Wan, M. Krahn, W. J. Ungar, E. Caku, L. Sung, L. S. Medina, and A. S. Doria Acute Appendicitis in Young Children: Cost-effectiveness of US versus CT in Diagnosis--A Markov Decision Analytic Model Radiology, February 1, 2009; 250(2): 378 - 386. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Karmazyn, D. P. Frush, K. E. Applegate, C. Maxfield, M. D. Cohen, and R. P. Jones CT with a Computer-Simulated Dose Reduction Technique for Detection of Pediatric Nephroureterolithiasis: Comparison of Standard and Reduced Radiation Doses Am. J. Roentgenol., January 1, 2009; 192(1): 143 - 149. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. Chau, K. J. Poskitt, M. A. Sargent, B. A. Lupton, A. Hill, E. Roland, and S. P. Miller Comparison of Computer Tomography and Magnetic Resonance Imaging Scans on the Third Day of Life in Term Newborns With Neonatal Encephalopathy Pediatrics, January 1, 2009; 123(1): 319 - 326. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. R. Mayo Radiation Dose Issues in Longitudinal Studies Involving Computed Tomography Proceedings of the ATS, December 15, 2008; 5(9): 934 - 939. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. L. Ward, K. J. Strauss, C. E. Barnewolt, D. Zurakowski, V. Venkatakrishnan, F. H. Fahey, R. L. Lebowitz, and G. A. Taylor Pediatric Radiation Exposure and Effective Dose Reduction during Voiding Cystourethrography Radiology, December 1, 2008; 249(3): 1002 - 1009. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A N Desmond, K O'Regan, C Curran, S McWilliams, T Fitzgerald, M M Maher, and F Shanahan Crohn's disease: factors associated with exposure to high levels of diagnostic radiation Gut, November 1, 2008; 57(11): 1524 - 1529. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Chandarana, M. C. B. Godoy, I. Vlahos, A. Graser, J. Babb, C. Leidecker, and M. Macari Abdominal Aorta: Evaluation with Dual-Source Dual-Energy Multidetector CT after Endovascular Repair of Aneurysms--Initial Observations Radiology, November 1, 2008; 249(2): 692 - 700. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. D. Graf, H. R. Kayyali, J. J. Alexander, S. D. Simon, and M. C. Morriss Neuroimaging-Use Trends in Nonacute Pediatric Headache Before and After Clinical Practice Parameters Pediatrics, November 1, 2008; 122(5): e1001 - e1005. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J G Browning, A G Wilkinson, and T Beattie Imaging paediatric blunt abdominal trauma in the emergency department: ultrasound versus computed tomography Emerg. Med. J., October 1, 2008; 25(10): 645 - 648. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Baldisserotto, S. G. Valduga, and C. F. J. S. da Cunha MR Imaging Evaluation of the Normal Appendix in Children and Adolescents Radiology, October 1, 2008; 249(1): 278 - 284. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J A SOYE and A PATERSON A survey of awareness of radiation dose among health professionals in Northern Ireland Br. J. Radiol., September 1, 2008; 81(969): 725 - 729. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. S. Roach, M. R. Golomb, R. Adams, J. Biller, S. Daniels, G. deVeber, D. Ferriero, B. V. Jones, F. J. Kirkham, R. M. Scott, et al. Management of Stroke in Infants and Children: A Scientific Statement From a Special Writing Group of the American Heart Association Stroke Council and the Council on Cardiovascular Disease in the Young Stroke, September 1, 2008; 39(9): 2644 - 2691. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. H. Lee, J. M. Goo, H. J. Ye, S.-J. Ye, C. M. Park, E. J. Chun, and J.-G. Im Radiation Dose Modulation Techniques in the Multidetector CT Era: From Basics to Practice1 RadioGraphics, September 1, 2008; 28(5): 1451 - 1459. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. A. Bluemke, S. Achenbach, M. Budoff, T. C. Gerber, B. Gersh, L. D. Hillis, W. G. Hundley, W. J. Manning, B. F. Printz, M. Stuber, et al. Noninvasive Coronary Artery Imaging: Magnetic Resonance Angiography and Multidetector Computed Tomography Angiography: A Scientific Statement From the American Heart Association Committee on Cardiovascular Imaging and Intervention of the Council on Cardiovascular Radiology and Intervention, and the Councils on Clinical Cardiology and Cardiovascular Disease in the Young Circulation, July 29, 2008; 118(5): 586 - 606. [Full Text] [PDF]
|
|
|
|
|
|
J. E. Ngaile, C. B. S. Uiso, P. Msaki, and R. Kazema Use of lead shields for radiation protection of superficial organs in patients undergoing head CT examinations Radiat Prot Dosimetry, July 1, 2008; 130(4): 490 - 498. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. A. Lichtenstein and G. A. Meziere Relevance of Lung Ultrasound in the Diagnosis of Acute Respiratory Failure: The BLUE Protocol Chest, July 1, 2008; 134(1): 117 - 125. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. A. Mettler Jr, W. Huda, T. T. Yoshizumi, and M. Mahesh Effective Doses in Radiology and Diagnostic Nuclear Medicine: A Catalog Radiology, July 1, 2008; 248(1): 254 - 263. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Brink, J. Deunk, H. M. Dekker, D. R. Kool, M. J. R. Edwards, A. B. van Vugt, and J. G. Blickman Added Value of Routine Chest MDCT After Blunt Trauma: Evaluation of Additional Findings and Impact on Patient Management Am. J. Roentgenol., June 1, 2008; 190(6): 1591 - 1598. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. A. Lichtman Is There an Entity of Chemically Induced BCR-ABL-Positive Chronic Myelogenous Leukemia? Oncologist, June 1, 2008; 13(6): 645 - 654. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Cho, B. Seo, T. Choi, J. Kim, Y. Kim, J. Choi, Y. Oh, K. Kim, and S. Kim The development of a diagnostic reference level on patient dose for CT examination in Korea Radiat Prot Dosimetry, May 1, 2008; 129(4): 463 - 468. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. M. Atabaki, I. G. Stiell, J. J. Bazarian, K. E. Sadow, T. T. Vu, M. A. Camarca, S. Berns, and J. M. Chamberlain A Clinical Decision Rule for Cranial Computed Tomography in Minor Pediatric Head Trauma Arch Pediatr Adolesc Med, May 1, 2008; 162(5): 439 - 445. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E J HALL and D J BRENNER Cancer risks from diagnostic radiology Br. J. Radiol., May 1, 2008; 81(965): 362 - 378. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
U.K. Udayasankar, K. Braithwaite, M. Arvaniti, D. Tudorascu, W.C. Small, S. Little, and S. Palasis Low-Dose Nonenhanced Head CT Protocol for Follow-Up Evaluation of Children with Ventriculoperitoneal Shunt: Reduction of Radiation and Effect on Image Quality AJNR Am. J. Neuroradiol., April 1, 2008; 29(4): 802 - 806. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. A. Miller CT Scans on Children: Is This a Problem? Clinical Pediatrics, April 1, 2008; 47(3): 220 - 223. [PDF]
|
|
|
|
 |
|
 S. Masciari, A. D. Van den Abbeele, L. R. Diller, I. Rastarhuyeva, J. Yap, K. Schneider, L. Digianni, F. P. Li, J. F. Fraumeni Jr, S. Syngal, et al. F18-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography Screening in Li-Fraumeni Syndrome JAMA, March 19, 2008; 299(11): 1315 - 1319. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. M. Cavett Abdominal Ultrasound in Pediatric Trauma Patients AAP Grand Rounds, March 1, 2008; 19(3): 29 - 30. [Full Text] [PDF]
|
|
|
|
|
|
D. Honnef, J. E. Wildberger, G. Haras, C. Hohl, G. Staatz, R. W. Gunther, and A. H. Mahnken Prospective Evaluation of Image Quality with Use of a Patient Image Gallery for Dose Reduction in Pediatric 16-MDCT Am. J. Roentgenol., February 1, 2008; 190(2): 467 - 473. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P M Gustafsson, P A De Jong, H A W M Tiddens, and A Lindblad Multiple-breath inert gas washout and spirometry versus structural lung disease in cystic fibrosis Thorax, February 1, 2008; 63(2): 129 - 134. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Nishizawa, S.-I. Mori, M. Ohno, N. Yanagawa, T. Yoshida, K. Akahane, K. Iwai, and S.-I. Wada Patient dose estimation for multi-detector-row CT examinations Radiat Prot Dosimetry, January 1, 2008; 128(1): 98 - 105. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Coursey, D. P. Frush, T. Yoshizumi, G. Toncheva, G. Nguyen, and S. B. Greenberg Pediatric Chest MDCT Using Tube Current Modulation: Effect on Radiation Dose with Breast Shielding Am. J. Roentgenol., January 1, 2008; 190(1): W54 - W61. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. D. MacKenzie, J. Nazario-Larrieu, T. Cai, M. S. Ledbetter, M. A. Duran-Mendicuti, P. F. Judy, and F. J. Rybicki Reduced-Dose CT: Effect on Reader Evaluation in Detection of Pulmonary Embolism Am. J. Roentgenol., December 1, 2007; 189(6): 1371 - 1379. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. J. Brenner and E. J. Hall Computed Tomography -- An Increasing Source of Radiation Exposure N. Engl. J. Med., November 29, 2007; 357(22): 2277 - 2284. [Full Text] [PDF]
|
|
|
|
 |
|
 A. B. de Gonzalez, K. P. Kim, and J. M. Samet Radiation-induced Cancer Risk from Annual Computed Tomography for Patients with Cystic Fibrosis Am. J. Respir. Crit. Care Med., November 15, 2007; 176(10): 970 - 973. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Just da Costa e Silva and G. Alves Pontes da Silva Eliminating Unenhanced CT When Evaluating Abdominal Neoplasms in Children Am. J. Roentgenol., November 1, 2007; 189(5): 1211 - 1214. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A.B. Smith, W.P. Dillon, R. Gould, and M. Wintermark Radiation Dose-Reduction Strategies for Neuroradiology CT Protocols AJNR Am. J. Neuroradiol., October 1, 2007; 28(9): 1628 - 1632. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Chintagumpala, P. Chevez-Barrios, E. A. Paysse, S. E. Plon, and R. Hurwitz Retinoblastoma: Review of Current Management Oncologist, October 1, 2007; 12(10): 1237 - 1246. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Allen and C. T. Jones Emergency Department Use of Computed Tomography in Children With Epilepsy and Breakthrough Seizure Activity J Child Neurol, September 1, 2007; 22(9): 1099 - 1101. [Abstract] [PDF]
|
|
|
|
|
|
H. M. Branson, A. S. Doria, R. Moineddin, and M. M. Shroff The Brain in Children: Is Contrast Enhancement Really Needed after Obtaining Normal Unenhanced CT Results? Radiology, September 1, 2007; 244(3): 838 - 844. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Huda Radiation Doses and Risks in Chest Computed Tomography Examinations Proceedings of the ATS, August 1, 2007; 4(4): 316 - 320. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K Fujii, T Aoyama, S Koyama, and C Kawaura Comparative evaluation of organ and effective doses for paediatric patients with those for adults in chest and abdominal CT examinations Br. J. Radiol., August 1, 2007; 80(956): 657 - 667. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. B. Larson, S. B. Rader, H. P. Forman, and L. Z. Fenton Informing Parents About CT Radiation Exposure in Children: It's OK to Tell Them Am. J. Roentgenol., August 1, 2007; 189(2): 271 - 275. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. A. Campbell, R. P. Berger, L. Ettaro, and M. S. Roberts Cost-effectiveness of Head Computed Tomography in Infants With Possible Inflicted Traumatic Brain Injury Pediatrics, August 1, 2007; 120(2): 295 - 304. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. L. Hollingsworth, T. T. Yoshizumi, D. P. Frush, F. P. Chan, G. Toncheva, G. Nguyen, C. R. Lowry, and L. M. Hurwitz Pediatric Cardiac-Gated CT Angiography: Assessment of Radiation Dose Am. J. Roentgenol., July 1, 2007; 189(1): 12 - 18. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Inoue, T. Kobayashi, A. Morikawa, A. Taddio, C. D. Rose, G. F. Greil, W. J. Manning, J. W. Newburger, L. A. Sleeper, and J. C. Burns Treatment of Kawasaki Disease N. Engl. J. Med., June 28, 2007; 356(26): 2746 - 2748. [Full Text] [PDF]
|
|
|
|
|
|
R. S. Saleh, S. Patel, M. H. Lee, M. I. Boechat, O. Ratib, C. R. Saraiva, and J. P. Finn Contrast-enhanced MR Angiography of the Chest and Abdomen with Use of Controlled Apnea in Children Radiology, June 1, 2007; 243(3): 837 - 846. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. M. Atabaki Pediatric Head Injury Pediatr. Rev., June 1, 2007; 28(6): 215 - 224. [Full Text] [PDF]
|
|
|
|
|
|
R. C. Cantu, S. A. Herring, M. Putukian, the American College of Sports Medicine, P. R. Stricker, J. Moriarity, F. G. O'Connor, T. M. McCambridge, E. Small, D. T. Bernhardt, et al. Concussion N. Engl. J. Med., April 26, 2007; 356(17): 1787 - 1789. [Full Text] [PDF]
|
|
|
|
|
|
Y.-h. Kim, J.-h. Choi, C.-k. Kim, J.-m. Kim, S.-s. Kim, Y.-w. Oh, C.-y. Lee, D.-h. Kang, Y.-b. Lee, P.-k. Cho, et al. Patient dose measurements in diagnostic radiology procedures in Korea Radiat Prot Dosimetry, March 1, 2007; 123(4): 540 - 545. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. K. Rigsby, E. Gasber, R. Seshadri, C. Sullivan, M. Wyers, and T. Ben-Ami Safety and Efficacy of Pressure-Limited Power Injection of Iodinated Contrast Medium Through Central Lines in Children Am. J. Roentgenol., March 1, 2007; 188(3): 726 - 732. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Huda and A. Vance Patient Radiation Doses from Adult and Pediatric CT Am. J. Roentgenol., February 1, 2007; 188(2): 540 - 546. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. E. Ngaile, P. Msaki, and R. Kazema Current status of patient radiation doses from computed tomography examinations in Tanzania Radiat Prot Dosimetry, December 1, 2006; 121(2): 128 - 135. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. M. Snyder and B. D. Coley Limited Value of Plain Radiographs in Infant Torticollis Pediatrics, December 1, 2006; 118(6): e1779 - e1784. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Nakayama, K. Awai, Y. Funama, D. Liu, T. Nakaura, Y. Tamura, and Y. Yamashita Lower tube voltage reduces contrast material and radiation doses on 16-MDCT aortography. Am. J. Roentgenol., November 1, 2006; 187(5): W490 - W497. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. S. Doria, R. Moineddin, C. J. Kellenberger, M. Epelman, J. Beyene, S. Schuh, P. S. Babyn, and P. T. Dick US or CT for Diagnosis of Appendicitis in Children and Adults? A Meta-Analysis Radiology, October 1, 2006; 241(1): 83 - 94. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. R. Priest, D. A. Hill, G. M. Williams, C. L. Moertel, Y. Messinger, M. J. Finkelstein, and L. P. Dehner Type I Pleuropulmonary Blastoma: A Report From the International Pleuropulmonary Blastoma Registry J. Clin. Oncol., September 20, 2006; 24(27): 4492 - 4498. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J.-L. a. Geijerstam, S. Oredsson, M. Britton, and OCTOPUS Study Investigators Medical outcome after immediate computed tomography or admission for observation in patients with mild head injury: randomised controlled trial BMJ, September 2, 2006; 333(7566): 465. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. F. Thoeni and J. P. Cello CT Imaging of Colitis Radiology, September 1, 2006; 240(3): 623 - 638. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. A. Kurt, K. M. Winterhalter, R. H. Connors, B. W. Betz, and J. W. Winters Therapy of Parapneumonic Effusions in Children: Video-Assisted Thoracoscopic Surgery Versus Conventional Thoracostomy Drainage Pediatrics, September 1, 2006; 118(3): e547 - e553. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. I. Lee, H. V. Flaster, A. H. Haims, E. P. Monico, and H. P. Forman Diagnostic CT scans: institutional informed consent guidelines and practices at academic medical centers. Am. J. Roentgenol., August 1, 2006; 187(2): 282 - 287. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Allen, T. Demetriades, and D. J. Brenner Radiation risk overestimated. Radiology, August 1, 2006; 240(2): 613 - 614. [Full Text] [PDF]
|
|
|
|
 |
|
 D R Schmidt, B Hogh, O Andersen, J Fuchs, H Fledelius, and E Petersen The national neonatal screening programme for congenital toxoplasmosis in Denmark: results from the initial four years, 1999-2002. Arch. Dis. Child., August 1, 2006; 91(8): 661 - 665. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T Flohr and B Ohnesorge Developments in CT Imaging, June 1, 2006; 18(2): 45 - 61. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. K. Yousefzadeh, M. B. Ward, and C. Reft Internal Barium Shielding to Minimize Fetal Irradiation in Spiral Chest CT: A Phantom Simulation Experiment. Radiology, June 1, 2006; 239(3): 751 - 758. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. J. Barr, T. Ohlhaber, and C. Finder Focusing in on dose reduction: the FDA perspective. Am. J. Roentgenol., June 1, 2006; 186(6): 1716 - 1717. [Full Text] [PDF]
|
|
|
|
|
|
C. Humphrey, K. Duncan, and S. Fletcher Decade of Experience With Vascular Rings at a Single Institution Pediatrics, May 1, 2006; 117(5): e903 - e908. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
