HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by O'Reilly, R. J. Articles by Ronai, P. M. Search for Related Content PubMed PubMed Citation Articles by O'Reilly, R. J. Articles by Ronai, P. M.

Automatic Computer Analysis of Digital Dynamic Radionuclide Studies of the Cerebral Circulation

Institute of Medical and Veterinary Science, Adelaide, South Australia

Correspondence: For reprints contact: Peter M. Ronai, Director of Nuclear Medicine, The Institute of Medical and Veterinary Science, Box 14, Rundle St. Post Office, Adelaide, South Australia 5000.

ABSTRACT

This paper describes an empirical technique for automated off-line computer analysis of dynamic radionuclide studies of the cerebral circulation using a scintillation camera and associated digital data-acquisition equipment. The computer program carries out the following functions: (A) filtering and smoothing; (B) correction for nonuniform sensitivity of the gamma camera detector; (C) automatic selection of regions of interest corresponding to the cerebral hemispheres and avoiding the SSS, nasopharynx, and vascular structures at the base of the skull and neck (but including the calvarium with its external carotid blood supply); (D) normalization of data to the average region-of-interest area to correct for head asymmetry or rotation; and (E) plotting of histograms of total corrected counts/normalized region of interest/unit time, together with printout of L:R ratio at each data point.

The use of an automated analysis is ideally suited to high workload situations and the accuracy and speed of analysis are far greater than with the unsophisticated manual methods previously used. Individualized region-of-interest selection for each patient is preserved and at the same time the use of statistical criteria as a basis for region-of-interest selection results in absolutely reproducible regions of interest in a given patient. The program is an iterative one and can avoid abnormal blood pools in locating anatomical vascular landmarks during region-of-interest selection. The results of digital analysis using this technique have proved more sensitive in the detection of unilateral occlusive cerebrovascular disease than simultaneously recorded analog data.