Advances in positron tomography for oncology (original) (raw)
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Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2006
Dedicated positron emission mammography breast imaging systems have shown great promise for the detection of small, radiotraceravid lesions. Our group (a collaboration consisting of West Virginia University, Jefferson Lab and the University of Washington) is extending this work by developing a positron emission mammography-tomography (PEM-PET) system for imaging and biopsy of breast lesions. The system will have four planar detector heads that will rotate about the breast to acquire multi-view data suitable for tomographic reconstruction. Each detector head will consist of a 96 Â 72 array of 2 Â 2 Â 15 mm 3 LYSO detector elements (pitch ¼ 2.1 mm) mounted on a 3 Â 4 array of 5 Â 5 cm 2 flat panel position-sensitive photomultiplier tubes. PEM-PET is expected to have approximately two-millimeter resolution and possess the ability to guide the needle biopsy of suspicious lesions seen on the PET images. Initial tests of the scintillator arrays yielded excellent results. Pixel maps for all four scintillator arrays demonstrated that separation of the LYSO elements was very good; all of the LYSO array elements were observed, even in areas between individual PSPMTs. System energy resolution was measured to be 25% FWHM at 511 keV. Future work includes the use of field programmable gate arrays (FPGAs) to replace the current VME-based data acquisition system, a PSPMT gain normalization procedure to help improve response uniformity and energy resolution, and the addition of an x-ray source and detector to produce multi-modality PEM-PET-CT images of the breast. r
Recent developments in positron emission tomography (PET) instrumentation
NDT & E International, 1994
This paper presents recent detector developments and perspectives for positron emission tomography (PET) instrumentation used for medical research, as well as the physical processes in positron annihilation, photon scattering and detection, tomograph design considerations, and the potentials for new advances in detectors.
The role of positron emission tomography in oncology and other whole-body applications
Seminars in Nuclear Medicine, 1992
Imaging and quantifying biochemical and physiological processes with PET clearly has major potential significance for all organ systems and many disease states. Although the full utility and potential of emerging new applications of PET in organs other than the heart and brain must be demonstrated in basic and clinical research studies, the rapidly accumulating aggregate experience in oncology in particular, and in other organ systems and disease states as well, indicares that PET is now truly becoming a modality of both clinical and investigative use for the body as a whole as well as for specific organ systems. Wholebody PET FDG imaging (Fig 9) illustrates the potential of biochemical imaging to map the distribution of cancer throught the body. With the growing list of radiopharmacautical and quantitative techniques applicable to cancer studies with PET, this field will continue to realize significant growth. Copyright 9 1992 by W.B. Saunders Company p OSITRON emission tomography (PET) began primarily as a research tool for biochemical and physiological investigations of the brain and heart. 1 PET has also been established as a clinical modality for selected diseases of the heart and brain, and it is also becoming more widely used in other organ systems and disease states. In addition to the brain and heart, organ systems investigated with positron emitting radiopharmaceuticals include the lungs, 2-5 thyroid, 6 liver, 7 and skeletal system, 8 among others. An emerging application of PET of potentially major significance for both research and clinical practice is in the field of oncology. 9,1~ Because of the often disseminated distribution of cancer, PET imaging methods capable of including large regions of the body in the field of view are advantageous. 14 Additionally, it is necessary to understand how biochemical and physiological characteristics of organ systems affect
Positron emission tomography in oncology
British Medical Bulletin, 2006
Increasing access to positron emission tomography-computed tomography (PET-CT) has resulted in a shift towards functional imaging, being the primary tool in the assessment of viable tumour in oncology patients. In this review, we discuss the basic principles of this evolving technology and the radio-isotopes it employs. The main clinical applications of PET-CT are reviewed and some of the limitations of the technique are highlighted. Finally, we offer insight into possible future developments and how these modify current practice.
Latest achievements in PET techniques
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2003
Positron emission tomography (PET) has moved from a distinguished research tool in physiology, cardiology and neurology to become a major tool for clinical investigation in oncology, in cardiac applications and in neurological disorders. Much of the PET accomplishments is due to the remarkable improvements in the last 10 years both in hardware and software aspects. Nowadays a similar effort is made by many research groups towards the construction of dedicated PET apparatus in new emerging fields such as molecular medicine, gene therapy, breast cancer imaging and combined modalities. This paper reports on some recent results we have obtained in small animal imaging and positron emission mammography, based on the use of advanced technology in the field of scintillators and photodetectors, such as Position-Sensitive Detectors coupled to crystal matrices, combined use of scintillating fibers and Hybrid-Photo-Diodes readout, and Hamamatsu flat panels. New ideas and future developments are discussed. r
Potential Improvements in Instrumentation for PET
Physics and Engineering of Medical Imaging, 1987
This paper discusses the potential for improved detectors in Positron Emission Tomography (PET) and explores the ultimate limits that might be achieved in the areas of spatial resolution, sensitivity, and maximum imaging rates. It is shown that if an ultra-fast, high• efficiency scintillator and a thin, low-noise, positionsensitive photodetector were available, a multi-layer time-of-flight tomograph would be possible with a 10 em axial field of view, a 3-dimensional spatial resolution of 2 mm fwhm,.and >700,000 prompt unscattered coincidences per sec for 1 JLCi per cm 3 in a 20 em diam cylinder of water.
Novel detector technology for clinical PET
European Journal of Nuclear Medicine and Molecular Imaging, 2009
Introduction Positron emission tomography (PET) is the most sensitive of all medical imaging modalities for quantitatively probing biologic processes at the molecular level. However, spatial resolution in PET is significantly inferior to that of other imaging modalities that can provide exquisite images of the anatomy, such as X-ray computed tomography (CT) or magnetic resonance (MR) imaging. Objective It has been one of the outstanding challenges of the last decade to combine PET with these complementary imaging modalities in order to synergistically exploit the benefits of each modality and to enhance the role of PET in pre-clinical research as well as in clinical routine and research. Discussion The simple juxtaposition of tomographs around a common axial bed, such as with current PET/CT technology, is very successful in allowing sequential acquisition of PET and anatomical data. However, novel imaging combinations are being considered that would enable simultaneous, or at least concurrent, dual-modality imaging through combined PET/MR or PET/CT. The development of these new integrated instruments creates new bewildering challenges for PET detection systems, which, in addition to the ability to measure annihilation radiation in PET, must satisfy several other critical requirements.
Clear-PEM: A PET imaging system dedicated to breast cancer diagnostics
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2007
The Clear-PEM scanner for positron emission mammography under development is described. The detector is based on pixelized LYSO crystals optically coupled to avalanche photodiodes and readout by a fast low-noise electronic system. A dedicated digital trigger (TGR) and data acquisition (DAQ) system is used for on-line selection of coincidence events with high efficiency, large bandwidth and small dead-time. A specialized gantry allows to perform exams of the breast and of the axilla. In this paper we present results of the measurement of detector modules that integrate the system under construction as well as the imaging performance estimated from Monte Carlo simulated data.
Medical Physics, 2007
We studied the performance of a dual-panel positron emission tomography ͑PET͒ camera dedicated to breast cancer imaging using Monte Carlo simulation. The PET camera under development has two 10ϫ 15 cm 2 plates that are constructed from arrays of 1 ϫ 1 ϫ 3 mm 3 LSO crystals coupled to novel ultra-thin ͑Ͻ200 m͒ silicon position-sensitive avalanche photodiodes ͑PSAPD͒. In this design the photodetectors are configured "edge-on" with respect to incoming photons which encounter a minimum of 2 cm thick of LSO with directly measured photon interaction depth. Simulations predict that this camera will have 10-15% photon sensitivity, for an 8 -4 cm panel separation. Detector measurements show ϳ1 mm 3 intrinsic spatial resolution, Ͻ12% energy resolution, and ϳ2 ns coincidence time resolution. By performing simulated dual-panel PET studies using a phantom comprising active breast, heart, and torso tissue, count performance was studied as a function of coincident time and energy windows. We also studied visualization of hot spheres of 2.5-4.0 mm diameter and various locations within the simulated breast tissue for 1 ϫ 1 ϫ 3 mm 3 , 2 ϫ 2 ϫ 10 mm 3 , 3ϫ 3 ϫ 30 mm 3 , and 4 ϫ 4 ϫ 20 mm 3 LSO crystal resolutions and different panel separations. Images were reconstructed by focal plane tomography with attenuation and normalization corrections applied. Simulation results indicate that with an activity concentration ratio of tumor🤱heart:torso of 10:1:10:1 and 30 s of acquisition time, only the dual-plate PET camera comprising 1 ϫ 1 ϫ 3 mm 3 crystals could resolve 2.5 mm diameter spheres with an average peakto-valley ratio of 1.3.