PURPOSE: The purpose of this study was to measure the absorbed dose and to calculate the effective dose for periapical radiography done by portable intraoral x-ray machines. MATERIALS AND METHODS: 14 full mouth, upper posterior and lower posterior periapical radiographs were taken by wall-type 1 and portable type 3 intraoral x-ray machines. Thermoluminescent dosemeters were placed at 23 sites at the layers of the tissue-equivalent ART woman phantom for dosimetry. Average tissue absorbed dose and radiation weighted dose were calculated for each major anatomical site. Effective dose was calculated using 2005 ICRP tissue weighted factors. RESULTS: On 14 full mouth periapical radiographs, the effective dose for wall-type x-ray machine was 30 Sv; for portable x-ray machines were 30 Sv, 22 Sv, 36 Sv. On upper posterior radiograph, the effective dose for wall-type x-ray machine was 4 Sv; for portable x-ray machines doses were 4 Sv, 3 Sv, 5 Sv. On lower posterior radiograph, the effective dose for wall type x-ray machine was 5 Sv; for portable x-ray machines doses were 4 Sv, 4 Sv, 5 Sv. CONCLUSION: Effective doses for periapical radiographs performed by portable intraoral x-ray machines were similar to doses for periapical radiographs taken by wall type intraoral x-ray machines.
Diagnostic Imaging ; Female ; Humans ; Mouth ; Radiation Monitoring ; Radiography* ; Radiography, Dental ; Radiometry ; Thermoluminescent Dosimetry

BACKGROUNDA novel radioactive 125I seed-loaded biliary stent has been used for patients with malignant biliary obstruction. However, the dosimetric characteristics of the stents remain unclear. Therefore, we aimed to describe the dosimetry of the stents of different lengths - with different number as well as activities of 125I seeds.

METHODSThe radiation dosimetry of three representative radioactive stent models was evaluated using a treatment planning system (TPS), thermoluminescent dosimeter (TLD) measurements, and Monte Carlo (MC) simulations. In the process of TPS calculation and TLD measurement, two different water-equivalent phantoms were designed to obtain cumulative radial dose distribution. Calibration procedures using TLD in the designed phantom were also conducted. MC simulations were performed using the Monte Carlo N-Particle eXtended version 2.5 general purpose code to calculate the radioactive stent's three-dimensional dose rate distribution in liquid water. Analysis of covariance was used to examine the factors influencing radial dose distribution of the radioactive stent.

RESULTSThe maximum reduction in cumulative radial dose was 26% when the seed activity changed from 0.5 mCi to 0.4 mCi for the same length of radioactive stents. The TLD's dose response in the range of 0-10 mGy irradiation by 137Cs γ-ray was linear: y = 182225x - 6651.9 (R2=0.99152; y is the irradiation dose in mGy, x is the TLDs' reading in nC). When TLDs were irradiated by different energy radiation sources to a dose of 1 mGy, reading of TLDs was different. Doses at a distance of 0.1 cm from the three stents' surface simulated by MC were 79, 93, and 97 Gy.

CONCLUSIONSTPS calculation, TLD measurement, and MC simulation were performed and were found to be in good agreement. Although the whole experiment was conducted in water-equivalent phantom, data in our evaluation may provide a theoretical basis for dosimetry for the clinical application.

Brachytherapy ; methods ; Computer Simulation ; Humans ; Monte Carlo Method ; Radiometry ; methods ; Thermoluminescent Dosimetry ; methods

PURPOSE: The aim of this study was to compare the effective dose for imaging of mandible between multi-detector computed tomography (MDCT) and cone-beam computed tomography (CBCT). An MDCT with low dose technique was also compared with them. MATERIALS AND METHODS: Thermoluminescent dosimeter (TLD) chips were placed at 25 organ sites of an anthropomorphic phantom. The mandible of the phantom was exposed using 2 different types of MDCT units (Somatom Sensation 10 for standard-dose MDCT, Somatom Emotion 6 for low-dose MDCT) and 3 different CBCT units (AZ3000CT, Implagraphy, and Kavo 3D eXaM). The radiation absorbed dose was measured and the effective dose was calculated according to the ICRP 2007 report. RESULTS: The effective dose was the highest for Somatom Sensation 10 (425.84 microSv), followed by AZ3000CT (332.4 microSv), Somatom Emotion 6 (199.38 microSv), and 3D eXaM (111.6 microSv); it was the lowest for Implagraphy (83.09 microSv). The CBCT showed significant variation in dose level with different device. CONCLUSION: The effective doses of MDCTs were not significantly different from those of CBCTs for imaging of mandible. The effective dose of MDCT could be markedly decreased by using the low-dose technique.
Cone-Beam Computed Tomography ; Mandible ; Multidetector Computed Tomography ; Sensation ; Thermoluminescent Dosimetry

The radiation exposure has multiple complication of various organs. Especially, the Food and Drug Administration has recently issued a bulletin warning of the risks of acute skin injury occurring during fluoroscopically guided procedures. Physicians need information about typical radiation doses during fluoroscopically guided various procedures and estimates of entrance skin dose must be monitored using thermoluminescent dosimetry, film badge dosimetry, pocket dosimetry and on-line computer system. Current National Council on Radiation Protection and Measurements recommended are that yearly total body dose should not exceed 50 mSv (5 rem) and that life time dose measured in millisieverts should not exceed one's age in years multiplied by 10. Types of skin injury are erythema, alopecia, dry desquamation, invasive fibrosis, dermal atropy, telangiectasia, moist desquamation, skin necrosis and secondary ulcer. Also, long-term exposure caused skin cancer. We experienced personally pigmentation on the finger nail and the hand after repeated fluoroscopically guided procedures. Thus, we report this case for giving warning to the physiatrist by the complications due to frequent exposure during procedures.
Alopecia ; Computer Systems ; Erythema ; Fibrosis ; Film Dosimetry ; Fingers ; Fluoroscopy ; Hand ; Humans ; Necrosis ; Pigmentation ; Radiation Protection ; Skin Neoplasms ; Skin* ; Telangiectasis ; Thermoluminescent Dosimetry ; Ulcer ; United States Food and Drug Administration

Total Skin Electron Beam Therapy (TSEBT) of linear accelerator has become use so as to be useful, 2~9 MeV of energy territories came to be used with mycosis fungoides and cutaneous lymphomas in the superficial lesion treatment which covers the major portion of the body. I treat a patient to Stanford technique in this study, and it is 60 degrees around the patients whom Stanford technique irradiated electronic beam to a linear accelerator in horizontal directions and there is a way a standard of TSEBT treat it to six located field (anterior, posterior, and four obliques) becoming. An each field does horizontally it and consist to beam of the two component which fitted the center to a suitable angle. a patient treats it to three dual field a day in order to make short treatment time. when a first day, we treat one dual field at anterior position and two dual field at posterior position. when the second day, treat one dual field at posterior position and two dual field at anterior position. Therefore, six dual field is finished in perfect periodic two days. we made cylindrical acrylic phantom, and I inserted a dosimeter film between phantom. in order to measure a dose distribution calculation before treat a patient, and a patient checked it in six field directions that got from a treatment. It is after that thermoluminescent dosimetry (TLD) as it uses Rando phantom and then measurement dose distribution in six field directions after attaching at chest, the right and left flank, a back after irradiation.
Electronics ; Electrons ; Humans ; Leukemia, Myeloid ; Leukemia, Myeloid, Acute ; Lymphoma ; Mycosis Fungoides ; Particle Accelerators ; Porphyrins ; Skin ; Thermoluminescent Dosimetry ; Thorax

Total Skin Electron Beam Therapy (TSEBT) of linear accelerator has become use so as to be useful, 2~9 MeV of energy territories came to be used with mycosis fungoides and cutaneous lymphomas in the superficial lesion treatment which covers the major portion of the body. I treat a patient to Stanford technique in this study, and it is 60 degrees around the patients whom Stanford technique irradiated electronic beam to a linear accelerator in horizontal directions and there is a way a standard of TSEBT treat it to six located field (anterior, posterior, and four obliques) becoming. An each field does horizontally it and consist to beam of the two component which fitted the center to a suitable angle. a patient treats it to three dual field a day in order to make short treatment time. when a first day, we treat one dual field at anterior position and two dual field at posterior position. when the second day, treat one dual field at posterior position and two dual field at anterior position. Therefore, six dual field is finished in perfect periodic two days. we made cylindrical acrylic phantom, and I inserted a dosimeter film between phantom. in order to measure a dose distribution calculation before treat a patient, and a patient checked it in six field directions that got from a treatment. It is after that thermoluminescent dosimetry (TLD) as it uses Rando phantom and then measurement dose distribution in six field directions after attaching at chest, the right and left flank, a back after irradiation.
Electronics ; Electrons ; Humans ; Leukemia, Myeloid ; Leukemia, Myeloid, Acute ; Lymphoma ; Mycosis Fungoides ; Particle Accelerators ; Porphyrins ; Skin ; Thermoluminescent Dosimetry ; Thorax

OBJECTIVE: The aim of this work was to determine the radiation dose received by infants from radiographic exposure and the contribution from scatter radiation due to radiographic exposure of other infants in the same room. MATERIALS AND METHODS: We retrospectively evaluated the entrance skin doses (ESDs) and effective doses of 23 infants with a gestational age as low as 28 weeks. ESDs were determined from tube output measurements (ESD(TO)) (n = 23) and from the use of thermoluminescent dosimetry (ESD(TLD)) (n = 16). Scattered radiation was evaluated using a 5 cm Perspex phantom. Effective doses were estimated from ESD(TO) by Monte Carlo computed software and radiation risks were estimated from the effective dose. ESD(TO) and ESD(TLD) were correlated using linear regression analysis. RESULTS: The mean ESD(TO) for the chest and abdomen were 67 micro Gy and 65 micro Gy per procedure, respectively. The mean ESD(TLD) per radiograph was 70 micro Gy. The measured scattered radiation range at a 2 m distance from the neonatal intensive care unit (NICU) was (11-17 micro Gy[corrected to 11-17 nGy]) per radiograph. Mean effective doses were 16 and 27 micro Sv per procedure for the chest and abdomen, respectively. ESD(TLD) was well correlated with ESD(TO) obtained from the total chest and abdomen radiographs for each infant (R2 = 0.86). The radiation risks for childhood cancer estimated from the effective dose were 0.4 x 10(-6) to 2 x 10(-6) and 0.6 x 10(-6) to 2.9 x 10(-6) for chest and abdomen radiographs, respectively. CONCLUSION: The results of our study show that neonates received acceptable doses from common radiological examinations. Although the contribution of scatter radiation to the neonatal dose is low, considering the sensitivity of the neonates to radiation, further protective action was performed by increasing the distance of the infants from each other.
Female ; Humans ; Infant, Newborn ; *Infant, Premature ; *Intensive Care, Neonatal ; Linear Models ; Male ; Monte Carlo Method ; *Radiation Dosage ; Radiography, Abdominal ; Radiography, Thoracic ; Retrospective Studies ; Risk Assessment ; Risk Factors ; Thermoluminescent Dosimetry ; Turkey