pépinière de luminy - 163 avenue de luminy - case 922 - 13288 marseille [email protected] – 1...

Pépinière de Luminy - 163 avenue de Luminy - case 922 - 13288 [email protected] – www.imxpad.com 1

New detectorsfor X-ray imaging


What makes the XPAD hybrid pixel detector better than CCDs & CMOS

ultra fast

> 1000

Yes

Excellent

No dark noise

Hybrid Pixels

Selective capture of ultra-fast phenomena

MediumElectronic

shutter

shooting films of ultra-fast phenomena

< 20Speed (images/s)

Better spoting

of the lesions

NoColor CT

Better precision

in diagnostic

GoodContrast

Lower dose

for the patient

strong limitation to image quality at low exposure

Background noise

ValueCCD & CMOS

ultra fast

> 1000

Yes

Excellent

No dark noise

Hybrid Pixels

Selective capture of ultra-fast phenomena

MediumElectronic

shutter

shooting films of ultra-fast phenomena

< 20Speed (images/s)

Better spoting

of the lesions

NoColor CT

Better precision

in diagnostic

GoodContrast

Lower dose

for the patient

strong limitation to image quality at low exposure

Background noise

ValueCCD & CMOS

Signal to noise

Frame rate (images/s)

ratio quality at low dose rate

Ultra fast

High diagnosticpower

New imagingarea

Shooting of ultra fast phenomena

Time resolved imaging

> 500


The markets

For the first two years, we aim to produce X-ray detectors for applications where we are already

well known, namely fundamental and applied research (material and protein crystallography,

monochromatic CT, …) and small animal imaging. Together with the CPPM, we will pursue R&D

on the development of a large CdTe detector in order to enter the huge market of color imaging.

SHORT TIME MARKETS FUTURE MARKETS

• Clinical imaging• Waste sorting• Homeland security• Non-destructive

control• Dental imaging


Reciprocal space tomography using the XPAD detector at SOLEIL

(courtesy: M. Gailhanou, CNRS/IM2NP)

imXPAD objectives

The company is created for the industrialization and commercialization of XPAD detectors of different sizes and dimensions. The first detectors will be of small and medium sizes, with the intent to increasing their dimension in a short time scale.

For an efficient launch, the company will benefit from the collaboration of experts and equipments from CPPM.

At start, the target market is the research on material sciences (synchrotrons and laboratories), either directly or via OEM. The market will then be soon extended to small animal imaging. Later on, other domains such as dental imaging, clinical angiography, clinical imaging, material survey and homeland security will be exploited.

At the same time, imXPAD will collaborate with CPPM experts on R&D, in particular by developing large CdTe detectors to set up and demonstrate color CT imaging, a new way of imaging X-rays that will bring CT into the world of molecular imaging.

imXPAD stands for “Imaging with the XPAD detector”. The XPAD detector (X-ray Pixel detector with Adaptable Dynamic range) is a hybrid pixel detector developed at the “Centre de Physique des Particules de Marseille” (CPPM, Université de la Mediterranee and CNRS/IN2P3).


imXPAD management team

Bernard DINKESPILER, President of imXPAD, is an electronics engineer who worked for more than 25 years at CNRS-IN2P3, in the field of high energy physics experiments. After leading the department of electronics of CPPM (20 people), he joined the hybrid pixel development team in 2005. He is the author of the patents on the readout architecture of the XPAD3 chip. He has spent a few years at SMU (Southern Methodist University, Dallas-Texas, USA) as a senior research associate.

Dr Pierre DELPIERRE, General Director of imXPAD, he is a scientist very well known in the international instrumentation community. He was at the origin of the hybrid pixel technology together with E. Heijne at CERN (Geneva, Switzerland). He was the project leader of the pixel detectors of the DELPHI (world premiere) and ATLAS experiments at CERN. The company will benefit of his scientific and technical experience, in particular for the research and development program. He is co-author of a patent that describes the use of photon counting for color CT. He was awarded the Crystal Prize of CNRS in 1997 and the Grand Prix of the French Academy of Sciences in 1999.

Christian MOREL, Scientific advisor, is a physics engineer. He is professor at the Department of Physics of the Aix-Marseille University and chairs the imXgam – X and gamma ray imaging group at CPPM. He will share his experience in the field of biomedical imaging by attending the Administration Council of the society. He is co-author of a patent that describes the use of photon counting for color CT. He was laureate of the ANR Programme « Chaires d’excellence » in 2005 and received the Rotblat Medal in 2009. He has been elected member of the IEEE NMISC from 2005 to 2008 and is member of the the French GDR MI2B (Modelling and Instrumentation for Bio-Medical Imaging) council since 2008.


The imXPAD team

imXPAD Management Board

Bernard Dinkespiler PresidentPierre Delpierre General DirectorChristian Morel Scientific Advisor

imXPAD operations and R&D

Technical division (3 persons)Commercial division (1 person)


Our partners

Technology transferhttp://mawww.in2p3.fr

Tests on micehttp://www.ibdm.univ-mrs.fr

XPAD tuning in synchrotron beamhttp://www.synchrotron-soleil.fr

R&D for color CThttp://imXgam.in2p3.fr

http://www.univmed.fr

http://www.cnrs.fr

XPAD tuning in synchrotron beamhttp://www.neel.cnrs.fr


XPAD technology

The XPAD detectors use the hybrid pixel technology developed for high energy physics. The idea is to provide a complete electronics analysis chain for each pixel in such a way that each pixel is able to suppress the noise by using a threshold set in energy, and then to count and to store the selected photons on its own.This electronics is embedded in a dedicated integrated circuit connected pixel by pixel on a pixelized X-ray sensor.As shown on the side picture, the photons are directly converted in the semi-conductor sensor, resulting in the creation of electric charges that are read out by the micro-electronics circuit.

Unlike the CCDs, the XPAD detectors proceed by direct detection and do not need a scintillator nor optical fibers. Moreover, they count photons one by one, instead of integrating an X-ray fluence. These two properties allow for providing a much sharper PSF function without blooming effect.


Innovation

XPAD hybrid pixel detector

As an example the following features of the XPAD detectors are not available with CCDs and CMOS pixels:

Noise suppression Energy selection Almost infinite dynamic range High Detection Quantum Efficiency (DQE(0) ≈ 100%,

dose reduction) Ultra fast electronic shutter (10 ns) Frame rate ~ 1 kHz

XPAD hybrid pixel detectorSignificant advantages of the XPAD, in particular considering the high dynamic range and the high frame rate, draw the interest of the professionals in material sciences (crystallography), who are working with laboratory sources as well as with high luminosity synchrotron beam light. The high quantum efficiency and the energy selection is prominent for biomedical imaging applications, since this allows for dose reduction and multi contrast agent imaging (color CT).

The XPAD detectors benefit from the hybrid pixel technology, which leads to major advantages with regards to the present detectors in use. These advantages are mainly provided by direct photon conversion and real time electronics analysis of the X-ray photons, allowing for direct photon counting. Moreover, the sensor material can be adapted to the range of energies of the impinging X-ray photons that is driven by the application.


The markets

All X-ray imaging field will benefit from the XPAD technology, thus opening a number

of markets for the imXPAD company. Any imaging process will find several advantageous

features in the list of specifications of the XPAD detectors, as shown in the table given

below.

XXAccurate time window

XXXXXFrame rate = 1 kHz

XXXXOn the fly readout

XXNo readout dead time

XXXXXXXXXLarge dynamic range

XXXXXXXXXDose reduction

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> 500 Hz


Products: XPAD 130 kpixels Silicon detector

Specifications

Dynamic range 32 bits: 1/ 4 x 109

Counting rate per pixel 5 x 105 cps (3 x 107 cps/mm2)Energy range 7 - 35 keVQuantum efficiency 99% @ 9 keV

70% @ 15 keV (measured)Energy resolution 1 keVThreshold range 5-30 keVThreshold dispersion 150 eVReadout time 2 msFraming rate 500 HzPoint-spread function 1 pixelCooling Air cooledPower consumption 14 W

Dimensions

Pixel size 130 x 130 µm2 Pixels number 134400 (560 x 240) pixelsArea 75 x 30 mm2

Sensor thickness 500 µmNumber of modules 1 (no inactive gap) Overall dimensions (WHD) 120 x 110 x 180 mm3 Weight 3 kg

Economic and plug and play silicon pixel detector for synchrotron beam light as well as laboratory X-ray tube applications.

The XPAD 130 kpixels is fully powered and interfaced. Just plug it on a PC. DAQ software is included with the detector delivery.



Fast medium size silicon pixel detector. In the standard version the modules are tiled (inclined by 7°) which saves significantly the dead area but it can also be assembled flat on request.

The XPAD 340 kpixels is delivered ready to use with the complete readout system (PC-interfaces, optical fibers and dedicated PC) and the DAQ software.

Specifications


Counting rate per pixel 5 x 105 cps (3 x 107 cps/mm2)

Energy range 7 - 40 keVQuantum efficiency 9 keV: 99%, 15 keV: 70% (measured)

Energy resolution 1 keV

Threshold range 5-30 kV

Threshold dispersion 150 eV

Readout time 2 ms

Framing rate 500 Hz

Point-spread function 1 pixel

Cooling Air-cooled

Power consumption 30 or 45 W

Dimensions

Pixel size 130 x 130 µm2

Pixels number 336 000 (560 x 600) pixelsArea 75 x 75 mm2 Sensor thickness 500 µmNumber of modules 5 or 8Gaps x=0, y=4pixels, 1,6% of total areaOverall dimensions (WHD) 135 x 230 x 250 mm3

Weight 4,5 kg



Fast medium size silicon pixel detector. In the standard version the modules are tiled (inclined by 7°) which saves significantly the dead area but it can also be assembled flat on request.

The XPAD 540 kpixels is delivered with the complete readout system (PC-interfaces, optical fibers and dedicated PC) and the DAQ software.

Specifications


Counting rate per pixel 5 x 105 cps (3 x 107 cps/mm2)

Energy range 7 - 40 keVQuantum efficiency 9 keV: 99%, 15 keV: 70% (measured)

Energy resolution 1 keV

Threshold range 5-30 kV

Threshold dispersion 150 eV

Readout time 2 ms

Framing rate 500 Hz

Point-spread function 1 pixel

Cooling Air-cooled

Power consumption 30 or 45 W

Dimensions

Pixel size 130 x 130 µm2

Pixels number 537 600 (560 x 960) pixelsArea 75 x 120 mm2 Sensor thickness 500 µmNumber of modules 5 or 8Gaps x=0, y=4pixels, 2,9% of total areaOverall dimensions (WHD) 135 x 230 x 250 mm3

Weight 5 kg


Products: XPAD 40 kpixels CdTe detector

Specifications


Counting rate per pixel 5 x 105 cps (3 x 107 cps/mm2)Energy range 8 - 70 keVQuantum efficiency 70% @ 15 keV, 80% @ 35 keV (measured)Energy resolution 600 eVAdjustable threshold range 8-70 keVThreshold dispersion 180 eVReadout time 2 msFraming rate 500 HzPoint-spread function 1 pixelCooling Air cooledPower consumption 10 W

Dimensions

Pixel size 130 x 130 µm2 Pixels number 38400 (160 x 240) pixelsArea 20 x 30 mm2

Sensor thickness 700 µmNumber of modules 1 (no gap) Overall dimensions (WHD) 120 x 110 x 180 mm3

Weight < 3 kg

Economic and plug and play CdTe pixel detector for synchrotron beam light as well as laboratory X-ray tube applications.

The XPAD 50 kpixels CdTe is fully powered and interfaced. Just plug it on a PC. DAQ software is included with the detector.


Since 1991, hybrid pixel detectors are being developed at CPPM for micro vertex trackers in high energy physics experiments. In 1996 the first hybrid pixel detector (in the world) was installed in the heart of the DELPHI (LEP, CERN, Geneva) experiment, under the direction of P. Delpierre, project leader. More recently, a vertex detector (2 m2 of Si hybrid pixels) has been installed in the heart of the ATLAS experiment on the Large Hadron Collider (LHC) at CERN (Geneva, Switzerland).

The origin of the XPAD technology

From the performance of the DELPHI pixel detector, it became obvious that the photon counting technology can also be applied to X-ray imaging and bring significant improvement. In 1998, the CPPM team working on the development of hybrid pixels started to develop a dedicated pixelized micro-electronics circuit for X-ray imaging. One year later the XPAD1 detector was born.


Fabrication of the first XPAD detectors

After some improvements, the XPAD2 circuit was produced and a large area (6,5 x 6 cm2) detector was built. At that time, it was the largest hybrid pixel detector in the world. It has been widely tested at the ESRF/CRG-D2AM beam line in Grenoble, and then at the new synchrotron SOLEIL near Saclay.

To assess the added value of hybrid pixels for biomedical imaging, a micro-CT scanner named PIXSCAN was developed at CPPM using the XPAD2 detector.

The third version of the detector named XPAD3 was developed in collaboration with the Néel/ESRF laboratory and the detector group of the synchrotron SOLEIL. Several large size (7.5 x 12 cm2) detectors have been produced at CPPM together with the associated software. These detectors have been largely tested on synchrotron beams as well as on the PIXSCAN micro-CT scanner.

As a result, the XPAD technology is now ready for industrialization.


XPAD detectors versus CCD on synchrotron experiments

Diffusion by a quasi-crystal of AlPdMn(courtesy: NEEL-CNRS/D2AM-CRG/ESRF,

Grenoble, France)

The large high dynamic range of XPAD detectors allows to observe simultaneously the high intensity Bragg peak and diffuse structures that shows the intrinsic “disorder” characteristic of quasi crystals.

Moreover, the data obtained with the XPAD detector follow a pure Poisson statistics (σ = 26 for <434> photons), which results from photon counting and helps their physical interpretation.


The XPAD detectors at SOLEIL

RECIPROCAL SPACE TOMOGRAPHY (courtesy: SOLEIL/DiffAbs, Saint Aubin, France)

High resolution X-ray diffraction experiments on highly distorted semiconductor layers have strong experimental requirements: measuring the weak scattering from defects as well as the main diffraction peaks which might be more intense by 6 orders of magnitude.

Aim : to characterize distortions in a GaInAs layer epitaxially grown on a GaAs single crystal surface : these strains modify the electronic properties. They also enlarge the small peaks associated with defects that are located near major crystal peaks, here (111).

This type of experiments can not be performed with CCD’s. They are commonly done using crossed slits and scintillation counters by scanning each point, thus wasting a large amount of time (typically a factor 100) as compared when using the XPAD detector.


The XPAD detector for biomedical imaging

Cone beam scans with the PIXSCAN micro-CT scanners

(courtesy: imXgam team, CPPM)

Improvements in medical imaging are expected thanks the XPAD detectors:

Large DQE conferred by an optimal efficiency that results from the use of high density sensor material, thus aiming at dose reduction

High speed data acquisition and high frame rate

Improved contrast thanks the exceptional noise free and energy selection properties of the XPAD detectors that allows for the subtraction of image taken at different energies before and after the absorption edges of contrast agents.

To test these properties, two micro-CT scanners have been built at CPPM. The first scanner was using the XPAD2 detector (figure a), whereas the second one is using the XPAD3 detector (figure b and c).

b)

a)

c)


Tumor growth monitoringMonitoring tumor mass expansion from repeated imaging sessions every 3-4 days from the second week post injection (D14 to D24). Maximum section of the tumor has been underlined (yellow) and its area was plotted versus time (courtesy: F. Debarbieux, IBDML, France).

The XPAD detector for tumor growth studyDose reductionBecause of the large DQE of the XPAD detector, low dose CT scans are possible. As an example, with 10 mGy only (more than 20 times less than the usual dose for small animal CT) a lung tumor is still visible (yellow arrow). This allows for repeated examinations of the same mouse.

D14 D18 D21 D24

Tumor area evolution

Day post injection

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The XPAD detector for cancer research

Simultaneous PET/CT images of a dead mouse with an inserted 22Na sealed source done with the ClearPET/XPAD prototype.

The imXgam research team at CPPM succeeded a simultaneous PET/CT scan of a mouse.

Positron Emission Tomography (PET) allows for imaging tumors, whereas X-ray CT scans the anatomy. Fusion of PET and CT images are used to localize the position of the tumors with respect to the anatomy. Sate-of-the art PET/CT scanners do not allow to acquire PET and CT data at the same time. If the patient of the animal moves between the two examinations (even by breathing) the fusion of the images might not be precise. Simultaneous PET/CT scans are true co-registration of both modalities. Ultimately, CT images can be used to correct for respiratory or cardiac movements

On the picture Kidneys and lungs are segmented and appear grey. The left image shows only the CT data (volume rendering of the 22Na salt bullet and bones), the right image shows PET data (in red) fused with CT data (courtesy: imXgam team, CPPM).


How to contact us

Contacts

B. Dinkespiler, P.A. Delpierre

[email protected]

[email protected]

Address

imXPAD S.A.S.Pépinière du Grand LuminyZone Luminy EntreprisesCASE 922 13288 MARSEILLE Cedex 09

E. [email protected]

pépinière de luminy - 163 avenue de luminy - case 922 - 13288 marseille [email protected] – 1...

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