Practical advices for optimal CT scanner dose in children

Radiation protection and dose optimisation in computerized tomography (CT) for pediatric patients are of utmost importance because of the potential risk of cancer induction by exposure to ionizing radiation. A review of available technical features in modern CT machines aiming at reducing and/or optimizing patient dose was performed. Practical advices to operators were listed according to dose-related technical solutions studied to decrease the doses and to practically implement dose optimisation

Conceptual design for assembly in aerospace industry: A method to assess manufacturing and assembly aspects of product architectures

In recent years, the air transport market has quickly grown, creating new civil aircrafts demand, challenging the actual production rate of aerospace industries. The bottleneck of the current civil aircrafts production rate lies in the capability of the manufacturing and assembly facilities in relation to the aircrafts architecture design. The aim of this work is to develop a methodology and a related mathematical model that can be used at the conceptual design phase for the assessment of criticalities related to the product assemblability. The methodology allows to recognize modules and/or interfaces which are mostly affecting the assembly time providing a design tool for the comparison and evaluation of product architecture alternatives. A preliminary application has been done on the nose-fuselage of a civil aircraft for passenger transport. The test case provides interesting outcome in the identification of modules and module interfaces which are strongly affecting the assembly phase and required a re-arrangement (new architecture design) for the process improvement

Design for Assembly in the Conceptual Development of Aircraft Systems

Conceptual design for assembly and installation is a key enabler for the improvement and development of an aircraft and related components. This work attempts to define a design for assembly methodology suitable for the evaluation and architecture design of aircraft systems in the preliminary phases of product development (conceptual design). Three main aspects are covered within this work: (i) the definition of a design framework, (ii) the characterization of suitable parameters driving the assessment and development of product architectures, and (iii) the formalization of internal knowledge for that purpose. The proposed approach has been tested in the assessment and development of an aircraft nose section with positive outcomes in terms of knowledge formalization and robustness of results in relation with the issues retrieved by the analysis of the assembly line. Future works will focus on the methodology optimization including automatic data input and mathematical models refinement

EXTRAPOLATION of DESIGN GUIDELINES during the CONCEPTUAL DESIGN PHASE: A METHOD to SUPPORT PRODUCT ARCHITECTURE DESIGN

The work aims at the definition of a design methodology able to drive designers in the definition of product architectures, starting from rough information available at the conceptual design. The methodology identifies design guidelines useful for the development of product architectures optimized for a given target (i.e. assembly, cost). The methodology is based on domains which combine attributes related to a specific aspect of the target. The exploratory application of the methodology was performed to address the equipment installation of a civil aircraft for assembly/installation target

Characterisation of grids of point detectors in maximum skin dose measurement in fluoroscopically-guided interventional procedures

Työssä on tutkittu uudentyyppisen ilmaisimen, termoloistedosimetreistä (TLD) muodostetun verkon, käyttöä toimenpideradiologian ihoannosmäärityksissä. Kyseiset mittaukset liittyvät yleensä toimenpiteisiin, joissa potilaan ihoannos on niin korkea, että ihovauriot ovat mahdollisia. Tutkimuksen tuloksena todetaan, että vaikka TLD-ilmaisimien hyvä energia- ja annosvaste puoltaa niiden käyttöä ihoannosmittauksissa, on verkon paikkaerottelukyky sen verran puutteellinen, että se johtaa hyvin suurella todennäköisyydellä ihoannoksen (merkittäväänkin) aliarvioon. Myös TLD-verkon lukeminen ja tulosten käsittely on työlästä suuresta ilmaisimien lukumäärästä johtuen

Measurement of maximum skin dose in interventional radiology and cardiology and challenges in the set-up of European alert thresholds

Toimenpideradiologiassa ja kardiologiassa potilaan iho saattaa saada niin suuren paikallisen säteilyannoksen, että ihovauriot (palovammat) ovat mahdollisia. Artikkelissa tutkitaan ja vertaillaan eri menetelmiä, jolla potilaan paikallinen ihoannoksen maksimi voidaan mittauksin määrittää. Mittausten yhtenä tarkoituksena on selvittää, voiko röntgenlaitteen raportoimaa annostietoa suoraan käyttää potilaan ihoannoksen määrittämiseen. Tuloksena todetaan, että vaikka joidenkin tutkimustyyppien osalta korrelaatio ihoannoksen ja laitteen näyttämän välillä onkin kohtalainen, yleispätevää korrelaatiota ei kuitenkaan pystytty löytämään. Täten esim. yhteiseurooppalaisten ihoannoksen hälytysrajojen asettaminen laitteen näyttämän perusteella on haastavaa

Feasibility of setting up generic alert levels for maximum skin dose in fluoroscopically guided procedures

International audiencePurpose The feasibility of setting-up generic, hospital-independent dose alert levels to initiate vigilance on possible skin injuries in interventional procedures was studied for three high-dose procedures (chemoembolization (TACE) of the liver, neuro-embolization (NE) and percutaneous coronary intervention (PCI)) in 9 European countries. Methods Gafchromic® films and thermoluminescent dosimeters (TLD) were used to determine the Maximum Skin Dose (MSD). Correlation of the online dose indicators (fluoroscopy time, kerma- or dose-area product (KAP or DAP) and cumulative air kerma at interventional reference point (Ka,r)) with MSD was evaluated and used to establish the alert levels corresponding to a MSD of 2 Gy and 5 Gy. The uncertainties of alert levels in terms of DAP and Ka,r, and uncertainty of MSD were calculated. Results About 20–30% of all MSD values exceeded 2 Gy while only 2–6% exceeded 5 Gy. The correlations suggest that both DAP and Ka,r can be used as a dose indicator for alert levels (Pearson correlation coefficient p mostly andgt;0.8), while fluoroscopy time is not suitable (p mostly andlt;0.6). Generic alert levels based on DAP (Gy cm2) were suggested for MSD of both 2 Gy and 5 Gy (for 5 Gy TACE 750, PCI 250 and NE 400). The suggested levels are close to the lowest values published in several other studies. The uncertainty of the MSD was estimated to be around 10–15% and of hospital-specific skin dose alert levels about 20–30% (with coverage factor k = 1). Conclusions The generic alert levels are feasible for some cases but should be used with caution, only as the first approximation, while hospital-specific alert levels are preferred as the final approach. © 2018 Associazione Italiana di Fisica Medic