Nuclear Medicine Imaging Instrumentation

Eberl, S. Zimmerman, R.E. Nuclear medicine imaging instrumentation. In Nuclear medicine in clinical diagnosis and treatment Ell, P.J., Gambhir, S.S., Eds. Churchill Livingstone Edinburgh, 2004 Vol. 2, 1765-1775. 

Among the most recent advances in the fusion of nuclear medicine images with computed tomography (SPECT/CT) and computed tomography angiography (SPECT/ CTA) in basic science studies in small animals, SPECT/CT was the topic of 11 instrumentation presentations, while PET/CT in small animals accounted for 5 presentations. 

Radiophannaceuticals are almost ideal diagnostic tools because radioisotope tracers do not alter body physiology, and they permit external monitoring with minimal instrumentation. Presently, there are three major areas of nuclear medicine (1) physiological function studies, (2) radionuclide imaging procedures, and (3) therapeutic techniques. 

Molecular imaging requires both the proper radioactive tracer and an instrument for imaging the tracer distribution witbin the living human body. Kuhl and Edwards (1963) were the first to describe tomography in nuclear medicine. Their invention preceded that of Houndsfield using x-ray transmission tomography (Figs. 6.2 and 6.3). 

The scintillation camera is the primary imaging instrument used in nuclear medicine and is often referred to as a gamma camera The scintillation camera is a position-sensitive gamma ray imager. Although the entire field of view is available for detection, it processes one event at a time. The spatial resolution is approximately 10 mm and it yields a count rate of 200 to 300 cpm//iCi in the field of view (cpm = counts per minute). The field of view covers a large portion of the body and is typically 40 X 50 cm, although other sizes are available. 

Rosenthal M. S., et al., Quantitative SPECT imaging A review and recommendations by the Focus Committee of the Society of Nuclear Medicine Computer and Instrumentation Council, /. Nucl. Med., 1995 36 1489-1513. 

Today the most useful chemical instrument is probably the nuclear magnetic resonance (NMR) spectrometer. Magnetic resonance imaging (MRI), vital in modern medicine, is derived from NMR. In late 1945, a physics group at Stanford, led by Felix Bloch (1905-83) (with William W. Hanson [1909-49] and Martin W. Packard), and one at Harvard, led by Edward M. Purcell (1912-97) (with Henry C. Tbrrey [1911-99] and Robert V. Pound [1919- ]), independently discovered the phenomenon of nuclear magnetic resonance. In order to manifest NMR an atomic nucleus must have nonzero nuclear spin. Of the roughly 100 stable isotopes that have nonzero nuclear spin, H, present in the vast majority of... 

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