![]() ![]() Source of radiation (>3 m) for measuring the background dose for each patient. Furthermore, a pair of TLD chips was located in the CT room far from the The National Medical Physics Research Center after 24 h, which has a special protocol for TLD analysis. It is notable that the readout and analysis of the TLDs were performed at Then the dose (mGy) versus TLD reading (nC) was plotted, and the CF was obtained by the slope of the curve. In the next step, to obtain the calibration factor (CF), the TLDs (ECC close to 1) were exposed three times to different selected doses, and the average of TLD readouts was calculated. The ECC for each TLD (TLD i) was calculated using the following Equation 1: The TLDs were irradiated three times in free-in-air conditionsĪt the center of rotation of the CT scanner, and the mean readout values of the TLDs (TLD mean) were obtained. Moreover, a Barracuda dosimeter (RTI Electronics, Sweden)Ĭalibrated at the Secondary Standard Dosimetry Laboratory (SSDL) was used for the verification of the dose measurement. In summary, the Element Correction Coefficient (ECC) values were obtained to increase the reproducibility for each TLD. The TLD chips’ calibration was done based on Groves et al. In a way that, the TLDs which were over or under sensitive by greater than 2 standard deviations were eliminated. The TLDs were exposed using an 80 kVp diagnostic X-ray beam, resulting in the use of a sensitivity correction, The dosimeters were pre-heated at 100☌ for 20 minutes (min). All TLDs were annealed in a TLD annealing furnace (1 h at 400 ☌ and 2 h at 100 ☌) before the measurements, and also prior to the readout, TLD chips are produced by Harshaw Company (Thermo Electron Corporation, Reading, UK) and made of LiF, Mg and Ti with the thickness of 0.9 mm and The advantage of our method is that the shielding instrument namely lead apron, positioned on the patients’ testis regions, is accessible in all CT centers. However, in the present study, we investigated the dose reduction effect of lead apron in the testicular region during chest MDCT procedures. Or a particular testicular shield which is hard to use. The previous studies were conducted on phantoms The authors estimated the gonads’ doses by an ion chamber in the presence of surface lead shield in RANDO anthropomorphic phantom during different CT scan examinations. Īssessed abdominal lead shielding on the gonad doses during the chest CT examination using RANDO phantom and TLDs. In several studies, the testes’ shielding effects during CT scans have been investigated. However, these shields are not widely used in routine CT examinations due to their hard placement, lack of hygienic tips, and accessibility. Including lead blankets, clam-shell style shields, bismuth shielding, male testicular shields, and flexible shields. There are various shields designed to reduce gonadal doses, Reducing the sensitive organs’ doses by appropriate easy applicable shields can be helpful in this regard ![]() The patient’s dose in CT procedures consists of primary X-ray beam and scatter components therefore, radiation shielding is a challenging issue Therefore, any methods which can reduce the dose withoutĪffecting the diagnostic image quality should be performed. (ICRP) reports, the weighting factor of this organ is higher than other sensitive organs, which is equal to 0.2 ,Īnd it contributes 20% of the effective whole-body dose. Testes are one of the radiosensitive organs and regarding the International Commission on Radiation Protection Protecting the organs especially sensitive ones from radiation damage during CT examinations is crucial ĬT scan from the chest is a primary diagnostic tool for common examination for diagnosing the diseases of the lung and other organs located in the chest region In addition, with the introduction of multi-detector CT (MDCT)įor the clinical applications, a further increase in the overall number of CTs has been reported. Or carcinogenesis which may appear in the newborns, concern about it has increased Since ionization radiation can cause genetic side effects due to the higher diagnostic value of CT images. at an annual rate of 10 percent in the U. Īlthough in CT procedures, the collective effective dose is higher compared to other modalities such as common radiographies, the number of CT examinations is continually increasing , and is known as one of the main contributors to the collective effective dose and also accounts for approximatelyĦ8% of the total medical radiation exposure in the world. ![]() Computed tomography (CT) using ionizing radiation, is widely used as an appropriate choice for the diagnosis of many diseases ![]()
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