High-resolution circular ring positron tomograph with dichotomic sampling: Dichotom-I.

Journal Article (Journal Article)

The circular ring transaxial positron camera developed earlier was refitted with a new dichotomic sampling scheme and aperture collimators on the detector array to improve the sampling and the overall system resolution. The z-axis slice thickness collimators were also limited to 1 cm, which corresponds to a slice thickness of 0.5 cm FWHM. Two different types of aperture collimators were adopted for high resolution (HR) and very high resolution (VHR) imaging, respectively. In HR mode a resolution of 6.5 mm FWHM was obtained without appreciable degradation of overall sensitivity, which represents a threefold improvement in resolution over the original system. In phantom studies with HR mode a sensitivity of 4500 counts s-1 muCi-1 cm-3 was obtained for a 20 cm diameter uniform phantom filled with water. A VHR mode experiment was also conducted to observe the ultimate resolution capability of the Dichotom-I system, and a resolution of 4.2 mm FWHM was obtained at the expense of sensitivity which was reduced by a factor of four from the HR mode experiment. The experience gained with Dichotom-I suggests a relatively simple and inexpensive modification of the existing NaI(T1) ring positron cameras, most of which suffer from low resolution due to poor sampling and poor intrinsic detector resolution.

Full Text

Duke Authors

Cited Authors

  • Cho, ZH; Hilal, SK; Ra, JB; Hong, KS; Bigler, RE; Yoshizumi, T; Wolf, AP; Fowler, JS

Published Date

  • November 1, 1983

Published In

Volume / Issue

  • 28 / 11

Start / End Page

  • 1219 - 1234

PubMed ID

  • 6606811

International Standard Serial Number (ISSN)

  • 0031-9155

Digital Object Identifier (DOI)

  • 10.1088/0031-9155/28/11/003


  • eng

Conference Location

  • England