End-user survey for digital sensor characteristics: a pilotquestionnaire study

12nonenoneG LI; PF VAN DER STELT; JGC VERHEIJ; R SPELLER; A GALBIATI; F PSOMADELLIS; R TURCHETTA; S THEODORIDIS; G HALL; BS AVSET; FA TRIANTIS; LONGO R.G., Li; PF VAN DER, Stelt; Jgc, Verheij; R., Speller; A., Galbiati; F., Psomadellis; R., Turchetta; S., Theodoridis; G., Hall; Bs, Avset; Fa, Triantis; Longo, Renat

End-user survey for digital sensor characteristics: A pilot questionnaire study

Objective: To survey end-user opinions on dental digital sensor characteristics for the design of a new X-ray imaging sensor. Material and methods: 100 questionnaires were sent out to dentists and dental radiologists. The questionnaire consisted of six parts related to dental sensors. A: Details about the respondent; B: Prioritization of most important aspects of digital sensors; C: Rating advantages and D: disadvantages of digital sensors; F: Dental features that need to be enhanced by digital sensors; G: End-user comments. Results: Fifty-six questionnaires were returned. Contrast resolution and imaging time were assessed as the most and the least important aspects, respectively. Aspects considered as advantages by approximately 80% of respondents were: optimal contrast resolution, increased specificity, increased discrimination between diseased and healthy tissue, increased sensitivity, lower dose to the patient by more than 20%; as a disadvantage, increased patient dose was given. Dental features considered important by over 80% of the respondents were for intraoral radiographs: the visibility of caries, periapical, periodontal, and bone lesions; for panoramic radiographs: reduction of ghost images, image sharpness and bone. Bone and soft tissues on cephalograms and bone on temporomandibular joint (TMJ) tomograms were mentioned by over 70%. Conclusion: The most desired characteristic for a new sensor is contrast resolution. Dose saving is not considered as important unless it is more than 20%. Examination time is not a major issue. Caries, periapical and periodontal, and bone lesions for intraoral radiographs, reduction of ghost images, image sharpness and bone for panoramic radiographs were the most frequently mentioned dental features that should be enhanced by digital sensors. © 2006 The British Institute of Radiology

The I-Imas project: End-Users driven specifications for the design of a novel digital medical imaging system

The I-Imas (Intelligent Imaging Sensors) is an EU project whose objective is to design and develop intelligent imaging sensors and evaluate their use within an adaptive medical imaging system specifically tailored to Mammography and Dental Radiology. The system will employ an in line scanning technology approach and proposes the use of CMOS active pixels sensors. The I-Imas sensor will have the capability of processing the data on every pixel and be able to dynamically respond in real time to changing conditions during imaging recording. The result will be to minimise the radiation exposure to areas of low diagnostic information content while extracting the highest diagnostic information from region of high interest. The first phase of the I-Imas project deals with the characterisation of the key features in a medical image that carry the highest content of diagnostic information. With this objective in mind an End-Users Survey has been carried out. We have been distributed a questionnaire to experts in the field of mammography and dental radiology (the dental radiology results will be presented elsewhere): medical physicists, radiologists, radiographers and dentists. From this survey we have collected information about the most useful specifications to be implemented in the I-Imas imaging system. This paper discusses the results from the End-Users survey and considers design implications for the I-Imas sensors. © 2004 IEEE

The I-Imas Project: End-Users Driven Specifications for the Design of a Novel Digital Medical Imaging System

The I-Imas (Intelligent Imaging Sensors) is an EU project whose objective is to design and develop intelligent imaging sensors and evaluate their use within an adaptive medical imaging system specifically tailored to Mammography and Dental Radiology. The system will employ an in line scanning technology approach and proposes the use of CMOS active pixels sensors. The I-Imas sensor will have the capability of processing the data on every pixel and be able to dynamically respond in real time to changing conditions during imaging recording. The result will be to minimise the radiation exposure to areas of low diagnostic information content while extracting the highest diagnostic information from region of high interest. The first phase of the I-Imas project deals with the characterisation of the key features in a medical image that carry the highest content of diagnostic information. With this objective in mind an End-Users Survey has been carried out. We have been distributed a questionnaire to experts in the field of mammography and dental radiology (the dental radiology results will be presented elsewhere): medical physicists, radiologists, radiographers and dentists. From this survey we have collected information about the most useful specifications to be implemented in the I-Imas imaging system. This paper discusses the results from the End-Users survey and considers design implications for the I-Imas sensors. © 2004 IEEE

I-IMAS: A 1.5D sensor for high-resolution scanning

We have developed a 1.5 D CMOS active pixel sensor to be used in conjunction with a scintillator for X-ray imaging. Within the Intelligent Imaging Sensors (I-ImaS) project, multiple sensors will be aligned to form a line-scanning system and its performance evaluated with respect to existing sensors in other digital radiography systems. Each sensor contains a 512×32 array of pixels and the electronics to convert the collected amount of charge to a digital output value. These include programmable gain amplifiers (PGAs) and analogue-to-digital converters (ADCs). The gain of the PGA can be switched between one or two, to increase the sensitivity for smaller collected charge; the ADC is a 14-bit successive approximation with a sampling rate of 1.25 MHz. The ASIC includes a programmable column fixed pattern noise mitigation circuit and a digitally controllable pixel reset mode block. Here we will describe the sensor design and the expected performance. © 2006 Elsevier B.V. All rights reserved

A scanning system for intelligent imaging: I-ImaS.

I-ImaS (Intelligent Imaging Sensors) is a European project aiming to produce adaptive x-ray imaging systems using Monolithic Active Pixel Sensors (MAPS) to create optimal diagnostic images. Initial systems concentrate on mammography and cephalography. The on-chip intelligence available to MAPS technology will allow real-time analysis of data during image acquisition, giving the capability to build a truly adaptive imaging system with the potential to create images with maximum diagnostic information within given dose constraints. In our system, the exposure in each image region is optimized and the beam intensity is a function not only of tissue thickness and attenuation, but also of local physical and statistical parameters found in the image itself. Using a linear array of detectors with on-chip intelligence, the system will perform an on-line analysis of the image during the scan and then will optimize the X-ray intensity in order to obtain the maximum diagnostic information from the region of interest while minimizing exposure of less important, or simply less dense, regions. This paper summarizes the testing of the sensors and their electronics carried out using synchrotron radiation, x-ray sources and optical measurements. The sensors are tiled to form a 1.5D linear array. These have been characterised and appropriate correction techniques formulated to take into account misalignments between individual sensors. Full testing of the mammography and cephalography I-ImaS prototype is now underway and the system intelligence is constantly being upgraded through iterative testing in order to obtain the optimal algorithms and settings. In preliminary simulations the dose savings between the regulated images and the reference images were estimated to between 30 to 70%