Estimation of occupational radiation doses in neuroendovascular procedures.

To estimate the mean effective dose per procedure with multiple dosimetry, to calculate the annual effective dose to personnel working in neuroendovascular procedures and compared with methods reported in the literature and with national and international limits. The radiation dose to personnel was monitored in 20 procedures classified as diagnostic or therapeutic. During each procedure, the equivalent dose to eyes, thyroid, under and over the lead apron at chest level, hands, gonads and knees was measured with lithium fluoride thermoluminescent dosimeter chips (TLD-100).

Present status of Medical Physics practice in Mexico: An occupational analysis.

Purpose: To present an overview of the status of Medical Physics practice in Mexico, promote the legal recognition of Medical Physics high-end training, and provide information that will potentially improve the Mexican healthcare system.

Methods: For the purpose of this research, the concept of "Medical Physics Professional/s" (MPP) is introduced to refer to any person/s executing the role of a clinical medical physicist (cMP) in whole or in part independent of academic profile, training or experience. A database of MPP in Mexico was built from official sources and personal communication with peers.

Peak skin and eye lens radiation dose from brain perfusion CT: CTDI and Monte Carlo based estimations.

Purpose: To quantify the eye lens, peak skin and brain doses associated with head CT perfusion exam by means of thermoluminescent dosimeters (TLDs) measurements in a cadaver and compare them to Monte Carlo (MC) dose estimations as well as to the CTDI.

Method: 18 TLDs were inserted in the brain, skin, and eye lenses of a female cadaver head, who underwent a CT brain perfusion scan using a Siemens Definition Flash. The table-toggling protocol used 80 kVp, 200 mAs, 32 × 1.

Do we need 3D tube current modulation information for accurate organ dosimetry in chest CT? Protocols dose comparisons.

Objectives: To compare the lung and breast dose associated with three chest protocols: standard, organ-based tube current modulation (OBTCM) and fast-speed scanning; and to estimate the error associated with organ dose when modelling the longitudinal (z-) TCM versus the 3D-TCM in Monte Carlo simulations (MC) for these three protocols.

Method: Five adult and three paediatric cadavers with different BMI were scanned. The CTDI of the OBTCM and the fast-speed protocols were matched to the patient-specific CTDI of the standard protocol.

Two examples of indication specific radiation dose calculations in dental CBCT and Multidetector CT scanners.

Purpose: To calculate organ doses and estimate the effective dose for justification purposes in patients undergoing orthognathic treatment planning purposes and temporal bone imaging in dental cone beam CT (CBCT) and Multidetector CT (MDCT) scanners.

Methods: The radiation dose to the ICRP reference male voxel phantom was calculated for dedicated orthognathic treatment planning acquisitions via Monte Carlo simulations in two dental CBCT scanners, Promax 3D Max (Planmeca, FI) and NewTom VGi evo (QR s.r.

Comparing different methods for estimating radiation dose to the conceptus.

Purpose: To compare different methods available in the literature for estimating radiation dose to the conceptus (D) against a patient-specific Monte Carlo (MC) simulation and a commercial software package (CSP).

Method: Eight voxel models from abdominopelvic CT exams of pregnant patients were generated. D was calculated with an MC framework including patient-specific longitudinal tube current modulation (TCM).

CUSTOMISATION OF A MONTE CARLO DOSIMETRY TOOL FOR DENTAL CONE-BEAM CT SYSTEMS.

A versatile EGSnrc Monte Carlo (MC) framework, initially designed to explicitly simulate X-ray tubes and record the output data into phase space data files, was modified towards dental cone-beam computed tomography (CBCT) dosimetric applications by introducing equivalent sources. Half value layer (HVL) measurements were conducted to specify protocol-specific energy spectra. Air kerma measurements were carried out with an ionisation chamber positioned against the X-ray tube to obtain the total filtration attenuation characteristics.

Clinical indications and radiation doses to the conceptus associated with CT imaging in pregnancy: a retrospective study.

Objective: To perform an internal audit at a university hospital with the aim of evaluating the number, clinical indication and operating procedure of computed tomography (CT) performed on pregnant patients and of estimating the radiation doses to the conceptus.

Methods: A retrospective review was conducted of all CT examinations performed in a single centre on pregnant patients between January 2008 and July 2013. The radiation doses to the conceptus were estimated.

Implementing the complete beam hardening effect of the bowtie filter versus scaling beam intensities: effects on dosimetric applications in computed tomography.

The bowtie filter is an essential element of computed tomography scanners. Implementation of this filter in a Monte Carlo dosimetry platform can be based on Turner's method, which describes how to measure the filter thickness and relate the x-ray beam as a function of bowtie angle to the central beam. In that application, the beam hardening is accounted for by means of weighting factors that are associated to the photons according to their position (fan angle) and energy.

Effective dose and organ doses estimation taking tube current modulation into account with a commercial software package.

Purpose: To evaluate the effect of including tube current modulation (TCM) versus using the average mAs in estimating organ and effective dose (E) using commercial software.

Method: Forty adult patients (24 females, 16 males) with normal BMI underwent chest/abdomen computed tomography (CT) performed with TCM at 120 kVp, reference mAs of 110 (chest) and 200 (abdomen). Doses to fully irradiated organs (breasts, lungs, stomach, liver and ovaries) and E were calculated using two versions of a dosimetry software: v.