Deparment of Medical Instruments Technology-Technological Educational Institution (Tei)

DEPARMENT OF MEDICAL INSTRUMENTS TECHNOLOGY-TECHNOLOGICAL EDUCATIONAL INSTITUTION (TEI) OF ATHENS - Greece

Contact

Organisation / TECHNOLOGICAL EDUCATIONAL INSTITUTION (TEI) OF ATHENS / Department / DEPARTMENT OF MEDICAL INSTRUMENTS TECHNOLOGY
Contact person / Kandarakis, Prof Ioannis
Email /
Address / Agiou Spyridonos
Postcode / 12210 / City / Aigaleo, Athens
Country / Greece
Telephone / +30210 5385387, +30210 5385303 / Fax / +0030-210-5385302
Website /

Organisation

Type: / Research Organisation & Universities
Description of research activity: / Group of scientists from the department of Medical Instruments Technology at the Technological Educational Institution (TEI) of Athens, Greece, with research interests in the medical imaging detectors.
Within this concept, the research team has been working in the last 15 years developing:
1. Experimental techniques for evaluating new scintillating materials (granular phosphors and single crystals) using X-rays and gamma-rays.
2. Mathematical models for predicting the suitability of scintillators for various medical imaging modalities. For this, we have developed custom computer software (code) for analytical models.
3. Monte-Carlo methods by either a/building own software for evaluating the performance of new scintillator materials, orb/using publicly available software (e.g. GATE, Geant4) for simulating the performance of scintillators integrated within complete medical imaging systems.The group has significant experience in the use of GATE Monte Carlo software for the simulation of clinical systems and prototypes. Until now, dedicated and clinical systems have been modeled, including:
•A small field of view gamma camera based on a R2486 PSPMT
•A mouse sized camera based on 2 H8500 PSPMTs
•A two head mini PET
•Siemens PET HR+
•Siemens PET Biograph
•Siemens Dual Head ECAM (SPECT)
In addition, GATE package is being used in order to model and correct scattering in SPECT imaging, produce data that will be used for scatter and attenuation correction in PET and in order to study the possibility of alternative collimator geometries.
4. Development of Dedicated Imaging Systems
The group works on the development of prototype systems for SPECT imaging in collaboration with international groups. We are specialized in detector components evaluation using phantoms. Recently we have extended our activities towards PET systems
5. Small Animal Imaging
A mouse sized camera has been built in collaboration with Jefferson Lab and it is now bein used in radiopharmaceutical studies in small mice in collaboration with National Radiopharmacological laboratories. Our group provides technical assistance for animal imaging, data processing and analysis as well as detector optimization. Currently a rotating gantry is being purchased in order to upgrade this camera to SPECT mode. The future goal is the use of two opposite heads for developing a mini-PET system and finally work towards a(S)PECT/CT detector.
6.Scintimammography
The group is interested in using a dedicated gamma camera based on a PSPMTs for breast studies. Currently we asses the performance of a R3292 PSPMT camera using phantoms. In addition we simulate breast studies and optimize acquisition parameters.
Members of the research group and collaborators
1.I. Kandarakis, Professor. Department of Medical Instruments Technology, Ionizing Radiations Laboratory, TEI of Athens
2.D. Cavouras, Professor. Department of Medical Instruments Technology, Medical Image and Signal Processing Laboratory, TEI of Athens
3.C. Nomicos, Professsor. Department of Electronics, TEI of Athens
4.N. Kalivas, Laboratory collaborator. Department of Medical Instruments Technology, Ionizing Radiations Laboratory, TEI of Athens.
5.I. Valais, Assistant Professor. Department of Medical Instruments Technology, TEI of Athens
6.A. Gaitanis, Institute of Biomedical Research of the Academy of Athens and Dept. of Medical Instruments Technology, TEI of Athens .
7.G. Loudos, Institute of Biomedical Research of the Academy of Athens
8.P. Liaparinos, Doctorate student, (in collaboration with the University of Patras)
9.S. David, Doctorate student, (in collaboration with the University of Patras)
10.C. Michail, Doctorate student, (in collaboration with the University of Patras
11. Collaboration with “Iaso” Hospital, Dept. of Radiotherapy
12. Collaboration with Dept of Medical Physics, University of Patras
13. Collaboration with Dept. of Medical Imaging, “Euromedica” MedicalCenter
14. Collaboration with Dept of Radiology, GeneralUniversity hospital Attikon
15.Collaboration with the 251 General Air Force Hospital (Athens).
EQUIPMENT OF RESEARCH LABORATORY
-Mouse sized gamma camera 5x10cm based on two H8500 PSPMTs with 2 PCI cards.
-Circular gamma camera for scintimammography based on a 10cm R3292 PSPMT with NIMA electronics and FAST ADCs.
-X-ray tube with Mo anode, film scanner, densitometers, sensitometers,
-Ionization chambers, dosimeter.
-Well counter detector, discriminators, MCA.
-CdZnTe solid-state detector for x-ray spectrometer.
-Portal imaging phantom, slit camera, MTF patterns.
- UV/IR (300-1000 nm) spectrophotometer.
- Spectrometer, intregrating spheres.
- Scintillating materials, photomultipliers, electrometers.
The results of the research team investigation have been published in refereeD publications and proceedings of international conferences (see attached list at

Former participation in an FP European project? NO

Research topics

• HEALTH-2007-1.2-1: Development of a hybrid imaging system.
• HEALTH-2007-1.2-2: Novel optical methodologies for detection, diagnosis and monitoring of disease or disease-related processes.
• HEALTH-2007-1.2-3: Novel targeted imaging probes for early in vivo diagnosis and/or evaluation of response to therapy.
• HEALTH-2007-2.4.1-4: Novel cancer screening methods.

Expertise/commitment offered

Keywords specifying the expertise: / Medical imaging, x-ray mammography, nuclear imaging, scintillators, phosphors, hybrid imaging systems, Monte Carlo
Description of the expertise: / I. Evaluation of powder phosphors and single crystal scintillators for application in medical imaging detectors*
Powder phosphors and single crystal scintillators are experimentally and theoretically evaluated under x-ray and gamma-ray exposure conditions. The aim of this research is to estimate the suitability of new scintillator and phosphor materials for use in radiation detectors of medical imaging systems in various fields, e.g. in Digital Mammography and Digital Radiography (DR), in Conventional Radiography, in x-ray Computed Tomography (CT), in Single Photon Emission Computed Tomography (SPECT), in Positron Emission Tomography (PET), in Portal Imaging (Imaging in Radiation Therapy). Parameters related to light emission efficiency; optical properties and imaging performance (MTF, NPS, DQE) are evaluated by the following methods and techniques:
1.Powder phosphor screen preparation: phosphor screens of various thicknesses and from various phosphor materials are prepared by sedimentation techniques. Screen coating thickness range from approximately 10up to 200 . Various materials (Terbium activated rare earth materials, Europium activated phosphors, and Cerium activated scintillators and phosphors as well as Cesium iodide crystals) have been tested.
2.Absolute luminescence efficiency measurements and calculations: The absolute luminescence efficiency (AE), (emitted light energy flux over incident exposure rate), is experimentally evaluated for powder phosphors and single crystal scintillators. Experiments are performed under Diagnostic Radiology and Nuclear Medicine conditions. Theoretical models, based on the Boltzmann diffusion equation, have been developed to describe radiation and light transport through phosphor/scintillator materials. The models are employed to perform AE calculations and to fit theoretical curves to experimental data. Fitting allows the determination of intrinsic physical parameters (intrinsic x-ray to light conversion efficiency, reciprocal light diffusion length etc)
3.Light emission spectrum measurements: The spectrum of light emitted by x-ray and gamma-ray excited phosphors and scintillators is experimentally evaluated. Spectral compatibility to optical sensors, currently employed in medical imaging detectors, is estimated.
4.Angular distribution of light emission: The angular distribution of light emitted by excited phosphors and scintillators is experimentally determined and used to assess the corresponding geometric light collection efficiency in various detector configurations
5.Image quality measurements and calculations: The imaging performance of powder phosphor screens is evaluated by Modulation Transfer Function (MTF) and Noise Power Spectrum (NPS) measurements and theoretical calculations. Using experimental AE, MTF and NPS data, the Signal to Noise Ratio (SNR) and the Detective Quantum Efficiency (DQE) (signal to noise ratio transfer efficiency) of the screens are determined. In addition theoretical models have been developed to fit image quality experimental curves.
______
*In collaboration with: Dept. of Medical Imaging, “Euromedica” Medical Center
II. Monte Carlo Simulations
Monte Carlo techniques are applied to study x-ray and gamma-ray radiation as well as optical photon transport through scintillator materials employed in radiation detectors of medical imaging systems.Special laboratory-developed Monte Carlo codes are used to simulate the radiation-matter interactions, the optical photon interactions (light absorption and light scattering effects) under various imaging conditions (Mammography, general purpose Diagnostic Radiology, and Nuclear Medicine-single photon and positron emission). Light transport through phosphor (granular scintillator) mass is simulated by a Monte Carlo code based on Mie light scattering theory. Monte Carlo simulation has allowed the determination of detector parameters (quantum detection efficiency, energy absorption efficiency, light transmission efficiency and overall luminescence efficiency) as functions of incident photon energy. In addition imaging characteristics such as MTF, Swank Factor and DQE are estimated.Up to now, various materials have been studied such as: Gd2O2S:Tb (GOS, GaDOX), YAlO3:Ce (YAP), Y3Al5O12:Ce (YAG), LuAlO3:Ce (LuAP), Gd2SiO5:Ce (GSO), Lu2SiO5:Ce (LSO) and (Lu,Y)2SiO5:Ce (LYSO:Ce).
GATE (Geant4 Application for Tomographic Emission) Monte Carlo code is also used to simulate clinical Positron Emission Tomography (PET) and Single Photon Emission Tomography (SPECT) systems. MCNP, GEANT4, EGS4 and DETEC2000 codes are also being under development for correlation purposes.
III. Simulation of a Computed Tomography Breast Imaging (CTBI) system
The aim of this project is to use analytical simulation methods to investigate the performance of a Computed Tomography Breast Imaging system. The effects of x-ray spectrum, detector material and reconstruction algorithm on image quality and on carcinoma and calcification detectability are investigated.
IV. Evaluation of Electronic Portal Imaging Devices (EPID)*
Electronic portal imaging devices (EPID) are used in Radiation Therapy for treatment field verification. EPID systems are evaluated using the PIPS-PRO portal imaging processing system consisting of a rectangular QC-3 phantom and corresponding software for image manipulation, feature extraction and registration. Portal images acquired during x-ray beam irradiation are imported into the PIPS-PRO system for analysis. Various imaging parameters (MTF, NPS, contrast) are estimated and image processing techniques are applied to improve portal image quality.
______
*In collaboration “Iaso” Hospital, Dept. of Radiotherapy
V. Magnetic resonance spectroscopy (MRS) and magnetic resonance spectroscopic imaging (MRSI)*
Aim of the current project is the parameter analysis, protocol optimization and clinical application of MRS and MRSI procedures in prostate, brain and skeletal muscle tissue diagnosis. More specifically various acquisition parameters and their effect in spectrum quality are investigated. A series of experiments are conducted, using phantoms, to assess the quality of various spectroscopy and spectroscopic imaging techniques. The effectiveness of the available water and lipid suppression techniques and their compatibility with other parameters is also investigated.
______
*Participation in the research program, entitled: “Combination of magnetic resonance spectroscopy and spectroscopic imaging in molecular imaging of prostate cancer” (scientific co-ordinator Assoc. Professor. Nikolaos Kelekis, 2nd Department of Radiology (MedicalSchool, University of Athens, GeneralUniversity hospital Attikon (17/1/2005 – 30/1/2006).
-Collaboration with the 251 General Air Force Hospital (Athens).
VI. Monte Carlo Simulation of imaging systems
The group has significant experience in the use of GATE Monte Carlo software for the simulation of clinical systems and prototypes. Until now, dedicated and clinical systems have been modeled, including:
•A small field of view gamma camera based on a R2486 PSPMT
•A mouse sized camera based on 2 H8500 PSPMTs
•A two head mini PET
•Siemens PET HR+
•Siemens PET Biograph
•Siemens Dual Head ECAM (SPECT)
In addition, GATE package is being used in order to model and correct scattering in SPECT imaging, produce data that will be used for scatter and attenuation correction in PET and in order to study the possibility of alternative collimator geometries. A GUI editor for GATE is being developed, in order to provide a user friendly interface for GATE users. Finally our investigates the use of GATE, in combination with realistic anthropomorphic phantoms (NCAT, Zubal) or small animal phantoms (MOBY), in order to simulate clinical trials or small animal experiments. Members of the group participate in openGATE collaboration
VII. Development of Dedicated Imaging Systems
The group works on the development of prototype systems for SPECT imaging in collaboration with international groups. We are specialized in detector components evaluation using phantoms. Recently we have extended our activities towards PET systems.
VIII. Small Animal Imaging
A mouse sized camera has been built in collaboration with Jefferson Lab and it is now bein used in radiopharmaceutical studies in small mice in collaboration with National Radiopharmacological laboratories. Our group provides technical assistance for animal imaging, data processing and analysis as well as detector optimization. Currently a rotating gantry is being purchased in order to upgrade this camera to SPECT mode. The future goal is the use of two opposite heads for developing a mini-PET system and finally work towards a(S)PECT/CT detector.
IX. Scintimammography
The group is interested in using a dedicated gamma camera based on a PSPMTs for breast studies. Currently we asses the performance of a R3292 PSPMT camera using phantoms. In addition we simulate breast studies and optimize acquisition parameters.
Commitment offered / Research,Training,Technology

Expectations

Expected results for your organisation: / -Improvement of biomedical imaging technology which will provide simultaneously anatomical and functional information in a fused final image.
-Simulation, design and possible development of a novel hybrid imaging system combining two or more different biomedical imaging modalities into a single system for concurrent measurement with the different modalities.
-Technology transfer and collaboration among research institutes and companies/industries in order to produce innovative diagnosis imaging systems
-Improving research collaboration among European research laboratories: enter European research Network in the field of medical imaging

PROJECT

Title: Development of a hybrid x-ray /nuclear imaging detector / Acronym: IMAGDET
Project type / Small or medium-scale focused research collaborative project
Status / Planned for submission
Call references / Call 1st
Priorities’ Main Research Areas / FP7-HEALTH-2007-A
FP7-HEALTH-1. BIOTECHNOLOGY, GENERIC TOOLS AND MEDICAL TECHNOLOGIES FOR HUMAN HEALTH
FP7-HEALTH-1.2. DETECTION, DIAGNOSIS AND MONITORING
Workprogramme Topic (according to each priority workprogramme) / HEALTH-2007-1.2-1: Development of a hybrid imaging system.
.
Project description
Today’s trend in medical imaging is the development of combined (hybrid) systems which give simultaneously anatomical and functional information in a fused final image. Those systems include two or even three different separated imaging detector units, though incorporated in one gantry. The scope of the present idea is the simulation, design and development of a detector, combining different imaging modalities e.g. Positron Emission Mammography (PEM)and x-ray Computed Tomography Breast Imaging (CTBI).The developed prototype will be tested at preclinical level (laboratory, animals)
Keywords / Medical imaging, PEM, x-ray mammography, nuclear imaging, scintillators, phosphors, hybrid imaging systems
Partners already involved / 1.Prof I. Kandarakis-TEI Athens-Greece, 2. University of Latvia, 3. ETSI Telecommunicacion- Universidad Politecnica de Madrid-Spain 4. Central Institute for Electronics-Germany
Project budget (for the running projects) / Budget reserved for SMEs

Profile of SME sought

Role / technology development, research, training
Country /region / All European countries (Member States & Associated countries)
Start of partnership / mid-term
Expertise required / -European health related SMEs and businesses developing medical imaging systems.
-Research groups and European SMEs involved in the design and/or development of high imaging performance radiation detectors, flat panel optical detectors and fast acquisition/ read out electronics.
-Research groups developing simulations and reconstruction algorithms in x-ray and in nuclear imaging systems.
-Partners with expertise in preclinical studies (prototype tested in laboratory, animals)

CONTACT DETAILS OF GREEK RESEARCH TEAM

Organisation / TECHNOLOGICAL EDUCATIONAL INSTITUTION (TEI) OF ATHENS / Department / DEPARTMENT OF MEDICAL INSTRUMENTS TECHNOLOGY
Contact person / Kandarakis, Prof Ioannis / Male/female / Male
Address / Agiou Spyridonos / Email /
Postcode / 12210 / Telephone / +30210 5385387;
+30210 5385303
City / Aigaleo, Athens / Fax / +0030-210-5385302
Country / Greece / Website /

HEALTH -2007 TOPICS OF EXPERTISE OF GREEK RESEARCH TEAM

DEADLINE FOR RESPONSES: 31/03/2007