scholarly journals Characterisation and mapping of scattered radiation fields in interventional radiology theatres

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Nowak ◽  
P. Carbonez ◽  
M. Krauss ◽  
F. R. Verdun ◽  
J. Damet
Keyword(s):  
Interventional Radiology ◽  
Radiation Protection ◽  
Staff Member ◽  
Scattered Radiation ◽  
Photon Counting ◽  
Medical Personnel ◽  
Pixel Detector ◽  
X Ray ◽  
Radiation Fields ◽  
Surveillance Programs

Abstract We used the Timepix3 hybrid pixel detector technology in order to determine the exposure of medical personnel to ionizing radiation in an interventional radiology room. We measured the energy spectra of the scattered radiation generated by the patient during X-ray image-guided interventional procedures. We performed measurements at different positions and heights within the theatre. We first observed a difference in fluence for each staff member. As expected, we found that the person closest to the X-ray tube is the most exposed while the least exposed staff member is positioned at the patient’s feet. Additionally, we observed a shift in energy from head to toe for practitioners, clearly indicating a non-homogenous energy exposure. The photon counting Timepix3 detector provides a new tool for radiation field characterisation that is easier-to-use and more compact than conventional X-ray spectrometers. The spectral information is particularly valuable for optimising the use of radiation protection gear and improving dosimetry surveillance programs. We also found the device very useful for training purposes to provide awareness and understanding about radiation protection principles among interventional radiology staff.

X-Ray Imaging of the Filling of “T” Shaped Microchannel Using a MEDIPIX2 Pixel Detector

2004 ◽  
Author(s):  
A. Vabre ◽  
E. Manach ◽  
O. Gal ◽  
S. Legoupil
Keyword(s):  
Measurement Technique ◽  
Chemical Engineering ◽  
Measurement Techniques ◽  
Photon Counting ◽  
Pixel Detector ◽  
Lab On Chip ◽  
X Ray ◽  
Space Resolution ◽  
Research Perspectives ◽  
European Collaboration

Fluid flows in “T” or “Y” shaped structures of microchannels are studied in order to develop modeling approaches as well as adapted measurement techniques. The applications of these structures are numerous and concern in particular biology and chemical engineering for which the integration of microchannels in lab-on-chip and/or microreactor is an important challenge. Our works concern the development of a measurement technique for the study of the filling of a “T” shaped microchannel structure by a liquid. In the studied channels, the experimental constraints are strong. Indeed, the space steps involved within the phenomena are very much reduced and vary from 1 to 10 μm. Moreover, the dynamics of the flow implies a high acquisition frequency, ranging from 10 to 100 Hz. Our technological choice is based on the measurement of the attenuation of an X-ray beam in the matter. The main advantage of this non-intrusive technique is that it can be implemented even in media opaque to visible light. Also, that X-ray techniques can theoretically reach a better space resolution than optical ones. The measurement technique is quantitative and a 3D measurement is achievable by tomography. These methods are validated for problems located at centimetric space steps and high acquisition frequencies, [1], [2]. The objective of this work is to match the microfluidics field requirement (space steps and attenuation contrast), while preserving high time frequencies. Our experimental bench consists of a X-ray generator, that makes possible to obtain high enlargements of the observed object whit a reduced blur in the image. The image is obtained by a pixel detector called Medipix2. This detector is under development within a European collaboration which gathers 16 partners around the CERN, the CEA being a partner. The main assets of this detector are its high space resolution, its operational photon counting mode and its high acquisition frequency. The presented works constitute a very first implementation and validation of the proposed technique for the microfluidics field. Experimental results are obtained and presented. They allow a measurement of the filling conditions of the “T” shape structure of microchannels. The orientations and research perspectives to improve the obtained results by the technique could be evaluated accurately and important basis of our work are now established and quantified for the future.

scholarly journals Characterization of the PILATUS photon-counting pixel detector for X-ray energies from 1.75 keV to 60 keV

2013 ◽  
Vol 425 (6) ◽  
pp. 062001 ◽  
Author(s):  
T Donath ◽  
S Brandstetter ◽  
L Cibik ◽  
S Commichau ◽  
P Hofer ◽  
...  
Keyword(s):  
Photon Counting ◽  
Pixel Detector ◽  
X Ray

A pixel detector-based single photon-counting system as fast spectrometer for diagnostic x-ray beams

2008 ◽  
Vol 129 (1-3) ◽  
pp. 119-122 ◽  
Author(s):  
C. Carpentieri ◽  
M. G. Bisogni ◽  
A. Del Guerra ◽  
P. Delogu ◽  
M. E. Fantacci ◽  
...  
Keyword(s):  
Single Photon ◽  
Photon Counting ◽  
Pixel Detector ◽  
Counting System ◽  
Single Photon Counting ◽  
X Ray

scholarly journals Timepix4, a large area pixel detector readout chip which can be tiled on 4 sides providing sub-200 ps timestamp binning

2022 ◽  
Vol 17 (01) ◽  
pp. C01044
Author(s):  
X. Llopart ◽  
J. Alozy ◽  
R. Ballabriga ◽  
M. Campbell ◽  
R. Casanova ◽  
...  
Keyword(s):  
Photon Counting ◽  
Data Driven ◽  
Time Of Arrival ◽  
Pixel Detector ◽  
Electrical Measurements ◽  
Large Area ◽  
X Ray ◽  
Information Time ◽  
Photon Counting Mode ◽  
5 Ghz

Abstract Timepix4 is a 24.7 × 30.0 mm2 hybrid pixel detector readout ASIC which has been designed to permit detector tiling on 4 sides. It consists of 448 × 512 pixels which can be bump bonded to a sensor with square pixels at a pitch of 55 µm. Like its predecessor, Timepix3, it can operate in data driven mode sending out information (Time of Arrival, ToA and Time over Threshold, ToT) only when a pixel has a hit above a pre-defined and programmable threshold. In this mode hits can be tagged to a time bin of <200 ps and Timepix4 can record hits correctly at incoming rates of ∼3.6 MHz/mm2/s. In photon counting (or frame-based) mode it can count incoming hits at rates of up to 5 GHz/mm2/s. In both modes data is output via between 2 and 16 serializers each running at a programmable data bandwidth of between 40 Mbps and 10 Gbps. The specifications, architecture and circuit implementation are described along with first electrical measurements and measurements with radioactive sources. In photon counting mode X-ray images have been taken at a threshold of 650 e− (with <10 masked pixels). In data driven mode images were taken of ToA/ToT data using a 90Sr source at a threshold of 800 e− (with ∼120 masked pixels).

Diagnostic radiology—Facility

2015 ◽  
Author(s):  
David G Sutton ◽  
Colin J Martin
Keyword(s):  
Radiation Protection ◽  
Scattered Radiation ◽  
Patient Dose ◽  
Diagnostic Radiology ◽  
X Ray ◽  
The Public ◽  
Room Design ◽  
Time Distance ◽  
Dose Constraints ◽  
Dose Levels

The exposure to radiation of staff and members of the public is restricted by seeking suitable compromises between the three basic elements of time, distance, and shielding. This chapter deals with the design of X-ray facilities to ensure that the distance and shielding elements are used appropriately. Criteria in the form of dose constraints for staff and the public based on the ALARP principle are used together with occupancies of adjacent areas to determine acceptable dose levels. Methods for calculating doses from workloads in terms of patient dose data are described. The results are then combined with the dose criteria to derive transmission requirements for protective barriers. Specific requirements for secondary scattered radiation and primary beams in radiography are considered. The methodology is described together with practical examples of room design for different X-ray techniques and elements of personnel radiation protection are discussed.

Interaction of ionizing radiations with matter

2015 ◽  
Author(s):  
Colin J Martin
Keyword(s):  
Radiation Dose ◽  
Scattered Radiation ◽  
Final Section ◽  
Radioactive Decay ◽  
Photoelectric Effect ◽  
X Rays ◽  
X Ray ◽  
Radiation Fields ◽  
Ionizing Radiations ◽  
Radiology Image

Interactions of ionizing radiations with matter are fundamental to the practice of radiation protection. They determine the magnitude and distribution of doses in tissues, the performance of detectors and imaging devices, and the attenuating properties of shielding materials. This chapter describes briefly the processes of radioactive decay and the properties of the various particles emitted, and then goes on to consider the interactions of radiation with matter. Electron interactions with metals result in bremsstrahlung and characteristic X-rays that form the basis of X-ray production. The interaction mechanisms of X-rays with tissue, particularly the photoelectric effect and Compton scattering, are inherent in the process of radiology image formation. Understanding the physics behind X-ray interactions so that scattered radiation can be taken into account is crucial in designing methods for accurately measuring radiation dose parameters. The final section deals with the dose related variables involved in measurement of radiation fields.

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