Abstract：
:The response characteristics of two tomographic systems were compared for imaging of positron emitters: a) a SPECT system with a 3/8 in crystal and 511 keV detector shielding, equipped with a specially designed 511 keV collimator, and b) a PET V system using coincidence detection. SPECT transverse plane resolution was 19 mm FWHM and 35 mm FWTM for a radius of rotation of 16 cm. Corresponding resolution for PET was 14 mm FWHM and 28 mm FWTM. Transverse images through a phantom containing cylindrical sources of various cross sections and uniform activity were obtained for each detector. The measured count density or recovery coefficient was found to decrease with source size, the dependence being similar for both systems. The theoretical values for recovery coefficients were calculated by convolution of a Gaussian fit to the SPECT resolution (FWHM, FWTM) values with the uniform cross section of each source. This simple mathematical model confirmed that the recovery coefficient dependence on source size was primarily related to the limited resolution of the detector. Experimental measurements demonstrated that the SPECT resolution for volume sources was sufficient for quantitation, although some limitations exist with respect to source sizes smaller than the detector resolution.
journal_name
IEEE Trans Med Imagingjournal_title
IEEE transactions on medical imagingauthors
Clarke LP,Cullom SJ,Kenny PJ,Saw CB,Silbiger MLdoi
10.1109/TMI.1986.4307776subject
Has Abstractpub_date
1986-01-01 00:00:00pages
177-82issue
4eissn
0278-0062issn
1558-254Xjournal_volume
5pub_type
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pub_type： 临床试验,杂志文章
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