Open AccessEvaluation of a chest phantom for CT nodule densitometry
Author(s) -
Gėrard De Geer,
G Gamsu,
C E Cann,
W. Richard Webb
Publication year - 1986
Publication title -
american journal of roentgenology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 196
eISSN - 1546-3141
pISSN - 0361-803X
DOI - 10.2214/ajr.147.1.21
Subject(s) - imaging phantom , densitometry , medicine , nuclear medicine , scanner , nodule (geology) , tomography , hounsfield scale , radiography , radiodensity , radiology , computed tomography , optics , paleontology , biology , physics
The characteristics of a chest phantom used for CT nodule densitometry were determined by use of a GE CT 9800 scanner (General Electric, Milwaukee, WI). The supplied reference rods were scanned in different positions within the lung fields of the phantom and with varied chest wall thicknesses. The liver/spleen inserts were added. The CT attenuation values of different-size rods and their mineral content were also tested. The size of the standard rod is the major determinant of its CT number, which varied from 1 to 83 H. The standard rods contained no measurable calcium or other mineral. Position-dependent variability in CT numbers was relatively small with the GE CT 9800 scanner. The simulated chest wall additions and liver/spleen inserts produced only small increases in CT density. We conclude that the GE CT 9800 scanner, as an example of one of the newer CT scanners, shows improved operating characteristics for pulmonary nodule densitometry. Nodule densitometry should be further evaluated with simplified phantoms.