Vatech PaX-i3D Smart, User Manual

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PaX-i3D Green (PHT-60CFO) User Manual
163
Appendices
3. C. THEODORAKOU, K. HORNER, K. HOWARD, A. WALKER: Pediatric
organ and effective doses in dental cone beam computed tomography
Dental CBCT has been associated with higher radiation risk to the patients
compared to conventional dental X-Ray imaging. Several studies have
investigated the radiation doses involved in dental CBCT for adults but none
has looked into pediatric doses. This study estimates the organ and effective
doses to two pediatric tissue-equivalent phantoms using thermo luminescent
dosimeters for three dental CBCT units and six imaging protocols. The doses
to the thyroid, salivary glands and brain ranged from 0.068mSv to 1.131mSv,
0.708mSv to 2.009mSv and 0.031mSv to 1.584mSv respectively. The skin
and red bone marrow have received much lower doses than the other three
organs. The effective doses ranged from 0.022 mSv to 0.081 mSv. The
effective doses calculated in this study were much higher than these of
panoramic X-Ray imaging but lower than conventional CT
4. CHIYO YAMAUCHI-KAWAURA & KEISUKE FUJII & TAKAHIKO AOYAMA
& SHUJI KOYAMA & MASATO YAMAUCHI: Radiation dose evaluation in
head and neck MDCT examinations with a 6-year-old child anthropomorphic
phantom, Pediatr Radiol (2010) 40:1206–1214 DOI 10.1007/s00247-009-
1495-z
Background: CT examinations of the head and neck are the most commonly
performed CT studies in children, raising concern about radiation dose and
their risks to children.
Objective: The purpose of this study was to clarify radiation dose levels
for children of 6 years of age undergoing head and neck multi-detector CT
(MDCT) examinations.
Materials and methods: Radiation doses were measured with small-sized
silicon-photodiode dosimeters that were implanted at various tissue and
organ positions within a standard 6-year-old anthropomorphic phantom.
Organ and effective doses of brain CT were evaluated for 19 protocols in
nine hospitals on various (2–320 detector rows) MDCT scanners.
Results: The maximum value of mean organ dose in brain CT was 34.3 mGy
for brain. Maximum values of mean doses for the radiosensitive lens and
thyroid were 32.7 mGy for lens in brain CT and 17.2 mGy for thyroid in neck
CT. seventy-fifth percentile of effective dose distribution in brain CT was
approximately the same as the diagnostic reference level (DRL) in the 2003
UK survey.
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