Comparative evaluation of organ and effective doses for paediatric patients with those for adults in chest and abdominal CT examinations

Fujii, Keisuke; Aoyama, T.; Koyama, Shuji; Kawaura, Chiyo

doi:10.1259/bjr/97260522

Cited by 73 publications

(44 citation statements)

References 21 publications

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“…These doses were similar to the doses reported elsewhere [15,24]. Considering chest, abdominal and pelvis examinations, median doses to the breast, lungs and gonads were in the range of those reported in the literature [15,24,28,29], with, as stated above, a large variation in dose according to the protocol. Effective doses were also calculated in our study in order to give a single dose value associated with an examination.…”

Section: Discussionsupporting

confidence: 87%

Radiation exposure from CT in early childhood: a French large-scale multicentre study

Bernier¹,

Rehel²,

Brisse³

et al. 2012

BJR

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Objectives: The increasing use of CT scans in the paediatric population raises the question of a possible health impact of ionising radiation exposure associated with CT scans. The aim of this study was to describe the pattern of CT use in early childhood. Methods: In 14 major French paediatric radiology departments, children undergoing at least 1 CT scan before age 5, between 2000 and 2006, were included. For each examination, absorbed organ doses were calculated. Results: 43% of the 27 362 children in the cohort were aged less than 1 year during their first exposure, with 9% being aged less than 1 month. The mean number of examinations per child was 1.6 (range 1-43). The examinations included: head in 63% of the cases, chest in 21%, abdomen and pelvis in 8% and others in 8%. Brain and eye lenses received the highest cumulative doses from head examinations, with mean organ dose values of 22 mGy (maximum 1107 mGy) and 26 mGy (maximum 1392 mGy), respectively. The mean cumulative effective dose was 3.2 mSv (range 0.1-189 mSv). Conclusion: CT scan exposure in childhood is responsible for relatively high doses to radiosensitive organs. The rather large dose range according to the protocols used requires their optimisation. The cohort follow-up will study the risk of long-term radiation-induced cancer.

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Section: Discussionsupporting

confidence: 87%

Radiation exposure from CT in early childhood: a French large-scale multicentre study

Bernier¹,

Rehel²,

Brisse³

et al. 2012

BJR

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“…Doses for breast tissue and lens were evaluated to be the doses for soft tissue at the position of the breast and the lens multiplied by the ratio of mass energy-absorption coefficient of breast tissue to soft tissue and of lens-to-soft tissue, respectively. Organ dose evaluation for red bone marrow and bone surface is the same as that described in previous papers [10,13], where the doses were evaluated from absorbed dose values measured in various bone tissues and the published data of the weight fractions of red bone marrow and mineralised bone [14].…”

Section: Evaluation Of Organ and Effective Dosesmentioning

confidence: 99%

Radiation dose evaluation in multidetector-row CT imaging for acute stroke with an anthropomorphic phantom

Yamauchi-Kawara

Fujii²,

Aoyama³

et al. 2010

BJR

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ABSTRACT. This study evaluated radiation dose and dose reduction in CT imaging for acute stroke. Radiation doses in three types of CT imaging (i.e. non-contrast-enhanced CT, CT perfusion (CTP) and CT angiography (CTA)) were measured with an in-phantom dosimetry system for 4-, 16-and 64-detector CT scanners in 5 hospitals. To examine the relationship between image quality and radiation dose in CTA, image contrast-to-noise ratio was evaluated. Doses to the brain, lens, salivary glands and local skin obtained with scan protocols in routine use were: 42-71 mGy, 30-88 mGy, 3.9-7.3 mGy and 40-97 mGy in non-contrast-enhanced CT; 41-75 mGy, 9.9-10 mGy, 1.5-2.1 mGy and 107-143 mGy in CTP; and 8.2-55 mGy, 26-69 mGy, 2.0-73 mGy and 32-72 mGy in CTA. For the combination of these CT examinations, on average a patient would receive 236 mGy for the maximum local skin dose and 4.2 mSv for the effective dose evaluated by the International Commission on Radiological Protection (ICRP) 103. Effective doses in CTP in this study were less than those obtained with representative protocols of Western countries. Average effective doses in each CT examination were not more than 1.5 mSv. The use of reduced kV and a narrow scan range would be effective in dose reduction of CTA and CTP, and intermittent scanning would be essential in CTP. Although lens and maximum local skin doses were far less than the thresholds for deterministic effects, since radiation risks would be increased in repeated CT examinations, efforts should be devoted to dose reduction in stroke CT examinations. Most patients with suspected stroke undergo either CT or MRI as the initial diagnostic examination [1,2]. MRI has some advantages over CT in depicting stroke lesions; however, the provision of MR scanners in general hospitals is still low, an examination takes more time and patients with pacemakers cannot undergo MRI examinations. While CT techniques carry the risk of radiation exposure, CT scanners are nearly always available [3] and scans can be done quickly. Schramm et al [4] have reported that CT images obtained by the combination of various CT examinations allow diagnostic assessment of acute stroke with a quality comparable with that of stroke MRI. So CT examination has some advantages for the diagnosis of acute stroke patients who have no time to lose.The diagnostic CT examination for acute stroke generally requires three imaging techniques: non-contrast-enhanced CT of the head; CT perfusion (CTP); and CT angiography (CTA) of intracranial vessels. In these CT examinations the local skin dose in CTP might be considerably high. In a previous study we reported that the maximum skin dose was as high as 712 mGy, 13 times higher than that in non-contrast-enhanced CT of the head [5]. Although the latest multidetector-row CT (MDCT) scanners have a dose reduction function of intermittent scanning or shuttle scanning, detailed patient doses using the function have not been reported.The CTA technique has been developing with great potential owing to high scan speed and ...

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“…Glass dosemeters have better reproducibility, less fading effect than the thermoluminescent dosemeter (23) . Although glass dosemeters are not read out in real-time like silicon pin photodiode (18,21) , the exposure doses were measured in several hundred positions at one time. Because the response of the glass dosemeter depends on X-ray energy in diagnosis region, effective energy and quality index used for comparative calibration were equalised to those of X-ray tubes in treatment room.…”

Section: Discussionmentioning

confidence: 99%

“…The bone marrow dose (d bone marrow ) and bone surface dose (d bone surface ) were estimated using the dosemeters inserted in bone. For bone marrow and bone surface, the conversions for absorbed doses to organ doses were based on the following equations (18) : …”

Section: Organ Dose Calculation Methodsmentioning

confidence: 99%

Estimation of organ doses and effective doses in image-guided respiration-gated radiotherapy

Nakao

Obara

Nabatame³

et al. 2015

Radiat Prot Dosimetry

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Dose conformity in thoracic and abdominal ion-beam radiotherapy is degraded by respiratory motion. To improve conformity, an image-guided respiration-gated system can be used in the treatment room. The purpose of this study was to estimate the organ doses and effective doses to patients from an image-guided respiration-gated system. Glass dosemeters were inserted into an adult anthropomorphic phantom and were attached to the surface on the phantom. The phantom was placed on the treatment couch, and the imaging dose from fluoroscopy was evaluated. In addition to the organ doses, the effective doses were also estimated according to the ICRP Publication 103. The irradiation time is over 3-5 min per beam angle. When image acquisition conditions were assumed for thoracic treatment, the effective doses and maximal skin doses were 0.48-0.79 mSv and 5.9-9.9 mGy, respectively. The estimated doses can be the base data for considering radiological protection in the radiotherapy.

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Comparative evaluation of organ and effective doses for paediatric patients with those for adults in chest and abdominal CT examinations

Cited by 73 publications

References 21 publications

Radiation exposure from CT in early childhood: a French large-scale multicentre study

Radiation exposure from CT in early childhood: a French large-scale multicentre study

Radiation dose evaluation in multidetector-row CT imaging for acute stroke with an anthropomorphic phantom

Estimation of organ doses and effective doses in image-guided respiration-gated radiotherapy

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