An update on computational anthropomorphic anatomical models

The prevalent availability of high-performance computing coupled with validated computerized simulation platforms as open-source packages have motivated progress in the development of realistic anthropomorphic computational models of the human anatomy. The main application of these advanced tools focused on imaging physics and computational internal/external radiation dosimetry research. This paper provides an updated review of state-of-the-art developments and recent advances in the design of sophisticated computational models of the human anatomy with a particular focus on their use in radiation dosimetry calculations. The consolidation of flexible and realistic computational models with biological data and accurate radiation transport modeling tools enables the capability to produce dosimetric data reflecting actual setup in clinical setting. These simulation methodologies and results are helpful resources for the medical physics and medical imaging communities and are expected to impact the fields of medical imaging and dosimetry calculations profoundly.</p

Radiation protection of patients in diagnostic and interventional radiology in Asian countries: Impact of an IAEA project

Recognizing the lack of information on image quality and patient doses in most countries in Asia, the International Atomic Energy Agency (IAEA) initiated a project to assess the status of imaging technology, practice in conventional radiography, mammography, computed tomography (CT) and interventional procedures, and to implement optimisation actions. A total of 20 countries participated. Obsolete practices of use of fluoroscopy for positioning, photofluorography, chest fluoroscopy and conventional tomography were reported by 4 out of 7 countries that provided this information. Low-kV technique for chest radiography is in use in participating countries for 20-85% of cases, and manual processing is in 5-85% of facilities in 5 countries. Instances of the use of adult CT protocol for children in three participating countries were observed in 10-40% of hospitals surveyed. After implementation of a Quality Control programme, the image quality in conventional radiography improved by zero to 13 percentage points in certain countries and dose reduction was from 10% to 85%. In mammography, poor quality, ranging from 10 to 29% of images in different countries was observed. The project increased attention to dose quantities and dose levels in computed tomography, although doses in most cases were not higher than reference levels. In this study 16-19% of patients in interventional cardiology received doses that have potential for either stochastic risk or tissue reaction. This multi-national study is the first of its kind in the Asia, and it provided insight into the situation and opportunities for improvement. (c) 2012 Elsevier Ireland Ltd. All rights reserved

Use of Multiphase CT Protocols in 18 Countries: Appropriateness and Radiation Doses

Purpose: To assess the frequency, appropriateness, and radiation doses associated with multiphase computed tomography (CT) protocols for routine chest and abdomen–pelvis examinations in 18 countries. Materials and Methods: In collaboration with the International Atomic Energy Agency, multi- institutional data on clinical indications, number of scan phases, scan parameters, and radiation dose descriptors (CT dose–index volume ; dose–length product [DLP]) were collected for routine chest (n ¼ 1706 patients) and abdomen–pelvis (n ¼ 426 patients) CT from 18 institutions in Asia, Africa, and Europe. Two radiologists scored the need for each phase based on clinical indications (1 ¼ not indicated, 2 ¼ probably indicated, 3 ¼ indicated). We surveyed 11 institutions for their practice regarding single-phase and multiphase CT examinations. Data were analyzed with the Student t test. Results: Most institutions use multiphase protocols for routine chest (10/18 institutions) and routine abdomen–pelvis (10/11 institutions that supplied data for abdomen–pelvis) CT examinations. Most institutions (10/11) do not modify scan parameters between different scan phases. Respective total DLP for 1-, 2-, and 3- phase routine chest CT was 272, 518, and 820 mGy_cm, respectively. Corresponding values for 1- to 5-phase routine abdomen–pelvis CT were 400, 726, 1218, 1214, and 1458 mGy cm, respectively. For multiphase CT protocols, there were no differences in scan parameters and radiation doses between different phases for either chest or abdomen–pelvis CT (P ¼ 0.40 0.99). Multiphase CT examinations were unnecessary in 100% of routine chest CT and in 63% of routine abdomen– pelvis CT examinations. Conclusions: Multiphase scan protocols for the routine chest and abdomen– pelvis CT examinations are unnecessary, and their use increases radiation dose

IAEA Survey of Pediatric CT Practice in 40 Countries in Asia, Europe, Latin America, and Africa: Part 1, Frequency and Appropriateness

OBJECTIVE. The purpose of this study was to assess the frequency of pediatric CT in 40 less-resourced countries and to determine the level of appropriateness in CT use. MATERIALS AND METHODS. Data on the increase in the number of CT examinations during 2007 and 2009 and appropriate use of CT examinations were collected, using standard forms, from 146 CT facilities at 126 hospitals. RESULTS. The lowest frequency of pediatric CT examinations in 2009 was in European facilities (4.3%), and frequencies in Asia (12.2%) and Africa (7.8%) were twice as high. Head CT is the most common CT examination in children, amounting to nearly 75% of all pediatric CT examinations. Although regulations in many countries assign radiologists with the main responsibility of deciding whether a radiologic examination should be performed, in fact, radiologists alone were responsible for only 6.3% of situations. Written referral guidelines for imaging were not available in almost one half of the CT facilities. Appropriateness criteria for CT examinations in children did not always follow guidelines set by agencies, in particular, for patients with accidental head trauma, infants with congenital torticollis, children with possible ventriculoperitoneal shunt malfunction, and young children ( LT 5 years old) with acute sinusitis. In about one third of situations, nonavailability of previous images and records on previously received patient doses have the potential to lead to unnecessary examinations and radiation doses. CONCLUSION. With increasing use of CT in children and a lack of use of appropriateness criteria, there is a strong need to implement guidelines to avoid unnecessary radiation doses to children