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Keywords | Technological sciences | health sciences | physical sciences | medical imaging |<br />
HI-CAM<br />
Development of a high-resolution<br />
Anger camera for diagnosis and<br />
staging of cancer diseases based on<br />
state of the art detector technology<br />
Summary<br />
The purpose of the project is the development of a compact<br />
and high-resolution Anger camera to be used in clinical<br />
and research environments and which allows earlier and<br />
more reliable diagnosis and therapy planning of cancer diseases<br />
in specifi c applications where high overall spatial<br />
resolution (less than 3 mm) and system compactness (less<br />
than 10 x 10 cm 2 fi eld of view) are required.<br />
The gamma camera is based on the well-established<br />
Anger architecture, where a collimator acts as a mechanical<br />
sieve for incoming gamma photons, a continuous<br />
scintillator uses the energy of each selectively passed<br />
gamma photon to generate visible photons, and an array<br />
of photodetectors emits electric signals in response to<br />
the absorption of the visible photons. The improvement<br />
of performances is based on the use of a particular type<br />
of photodetector, the Silicon Drift Detector (SDD), which<br />
has recently demonstrated its ability to provide better<br />
performance, by comparison with commonly used photomultiplier<br />
tubes.<br />
The camera is intended for use both single-handedly for<br />
planar scintigraphic studies and inserted in an annular<br />
holder (gantry) of small diameter for SPECT imaging.<br />
Thanks to its compactness and high spatial resolution,<br />
it off ers potential applications in early diagnosis of cancer<br />
diseases aff ecting areas of the human body which can<br />
only be imaged with diffi culty using the large and heavy<br />
imaging heads and gantries of commercial Anger cameras.<br />
The camera to be developed in the present project also<br />
off ers promising perspectives of integration at the system<br />
level with MRI instrumentation, thanks to the relative<br />
insensitivity of the SDD photodetectors to large magnetic<br />
fi elds.<br />
The research activity will be organised as follows: the fi rst<br />
two years of the three-year project will be dedicated to the<br />
development of the SDD-based Anger camera, while the<br />
third year will be dedicated to the experimentation of the<br />
camera in selected imaging applications related to cancer<br />
diagnosis and research.<br />
EARLY DETECTION, DIAGNOSIS AND PROGNOSIS<br />
Problem<br />
The state-of-the-art in the fi eld is represented by a range of<br />
commercial systems, usually having large fi eld detectors<br />
(~40x50 cm 2 ). These systems are best exploited while performing<br />
whole-body SPECT studies since their large, heavy<br />
PMT-based detector heads and bulky gantries present diffi -<br />
culties in operating close to the patient’s skin for dedicated<br />
studies of specifi c, small tissues such as in parathyroid imaging,<br />
brain scanning and investigation of kidney cancer in<br />
infants. In a realistic clinical setting, at an imaging distance<br />
usually rather greater than 20 cm, the overall eff ective spatial<br />
resolution is typically 10-16 mm (7-10 mm for brain<br />
studies). When a single detector head is used for dedicated<br />
scintigraphic studies of small organs, permitting a closer<br />
imaging distance, the overall eff ective spatial resolution is<br />
limited by both the intrinsic spatial resolution of the system<br />
and the collimator.<br />
Aim<br />
The aim of the project is therefore the development of a new<br />
compact and high position resolution (