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Recent Advances in Positron Emission Tomography Technology
Published in Krzysztof Iniewski, Biological and Medical Sensor Technologies, 2017
Farhad Taghibakhsh, Craig S. Levin
One method of improving the DOI resolution in multilayer crystal detectors is to couple each crystal layer to a separate photodetector. In this method, the DOI resolution and photon collection efficiency improves at the cost of increased photodetectors and electronics. In order to obtain continuous DOI information from monolayer crystal arrays, the dual-ended readout method was developed [25]. This method which extracts DOI by comparing the relative strengths of the signals obtained from the two ends of the crystal, might not be considered cost-effective because it requires a separate set of photodetectors and additional electronic processing circuitry. However, dual-ended readout can provide high DOI resolution down to 2.0 mm [26] and has been implemented in Clear-PEM, a dedicated positron emission mammography prototype system [27].
A Survey of Medical Imaging Systems
Published in Robert B. Northrop, Non-Invasive Instrumentation and Measurement in Medical Diagnosis, 2017
Positron emission mammography (PEM) is another new radiation modality used to detect potential breast cancers. PEM uses a pair of gamma radiation detectors placed on either side of the tissue under study to detect coincidence gamma rays following the administration of the radionuclide fluorine-18 fluorodeoxyglucose (18F-FDG), a metabolite used in whole-body PET studies for the detection of cancers (Glass and Shah 2013). 18F-FDG is taken up by a cancer cell's glucose transporter-1. Once inside the cell, the 18F-FDG is phosphorylated and cannot be transported out of the cell; thus it accumulates in the cell. The radioactive fluorine nucleus is unstable, and as it decays, an energetic positron is emitted. The collision of the positron with an electron results in the production of two 511 keV gamma photons which are emitted 180° from each other. These two gamma photons are detected as a coincidence event (CE) by a pair of gamma cameras placed above and below the breast under study. Coincidence data from the camera detector cells are assembled by a computer into a set of 12 slices each in the right craniocaudal, left craniocaudal, right mediolateral oblique, and left mediolateral positions. PEM breast imaging has 1.5 mm resolution in-plane and 5 mm between planes (Glass and Shah 2013). (The Solo II High-Resolution PET Scanner used in PEM is marketed by CMRNaviscan, San Diego, CA.)
Inverse Estimation of Breast Tumor Size and Location with Numerical Thermal Images of Breast Model Using Machine Learning Models
Published in Heat Transfer Engineering, 2023
Gonuguntla Venkatapathy, Anuj Mittal, Nagarajan Gnanasekaran, Vijay H. Desai
In order to detect early breast cancer, screening exams are intended to detect abnormalities as early as possible. Breast cancer can be treated more effectively, and there is a higher survival rate when detected early. Current screening methods for breast tumor detection include mammography [3], digital mammography [4], ultrasound, magnetic resonance imaging, positron emission mammography [5], breast-specific gamma imaging [6], clinical examinations, and thermography. Thermography is an adjunct screening tool, especially for patient screening. It is a quick, economical, noninvasive way of screening the surface temperature of the breast skin that does not involve contact, pain, radiation, or even medical intervention. It is a relatively straightforward imaging technique that detects changes in temperature on the human skin surface [7].