The design and clinical utilities of a fan beam collimator for a SPECT system
1984; Society of Nuclear Medicine and Molecular Imaging; Linguagem: Inglês
ISSN
1535-5667
AutoresB.M.W. Tsui, G.T. Gullberg, E. R. Edgerton, D.R. Gilland, T J Rho, Richard Johnston, J. R. Perry, William H. McCartney,
Tópico(s)Advanced Radiotherapy Techniques
ResumoA low-energy fan-beam collimator (LEFB) designed for SPECT imaging of the head was evaluated using physical measurements, phantom and clinical studies. In the transverse image plane, the collimator holes are tapered and converged to a focal point 58 cm from the collimator face. In the longitudinal image plane, the collimator holes are straight and parallel. The collimator holes are hexagonal in shape and 13 cm in length. The extended hole design allows improved clearance of the patient's shoulders during rotation such that the collimator face may be positioned 8.5 cm closer to the patient's head than is possible with conventional collimators. At the center of rotation with the closest rotational radius, the spatial resolutions for the LEGP, LEHR, and LEFB collimators are 17.0, 14.4 and 12.2 mm, respectively. The point source sensitivities are 330, 220 and 190 (at 15 cm) cpm/..mu..Ci, respectively. Line spread functions at various distances from the collimator face, both in air and in water, were measured. Reconstruction algorithms and a special attenuation correction method for the fan beam geometry were developed and various reconstruction parameters for the LEFB collimator were determined experimentally. Images of a SPECT phantom were obtained to evaluate the imaging capabilities of themore » LEFB collimator and the reconstruction algorithm. Clinical comparison of SPECT bone images of the temporomandibular joints obtained with both LEGP and LEFB collimators on the same patients show superior image quality with the LEFB collimator.« less
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