Three-dimensional computed tomographic angiography of pulmonary vessels.
OBJECTIVE
To assess the image quality of multiple threshold display (MTD) as a new technique for generating three-dimensional (3D) pulmonary computed tomographic (CT) angiographic images.


METHODS
We used MTD, a type of shaded surface display (SSD) offering the selection of multiple thresholds and transparencies, to reconstruct 3D-CT angiograms from enhanced helical CT data sets in 33 patients with lung disease. In MTD, eight thresholds of CT values are selected, and transparency is assigned to each. The selected voxels, ranging from -600 to 1,000 Hounsfield Units, were divided into eight classes, and transparency ranging from 0 to 100% was assigned to each. The CT scanner employed was a Toshiba Xvigor. MTD and SSD images were generated by using an Xtension with a Sun SPARC station 20, and they were compared by two radiologists.


RESULTS
The image quality of MTD images was superior to that of SSD images (p < 0.01), because the MTD images demonstrated clearly both the major and small vessels.


CONCLUSIONS
MTD is a useful technique for 3D pulmonary CT angiography.
Shimizu
T
T
Department of Radiology, Osaka Medical College, Japan.
Yoshikawa
S
S
Uesugi
Y
Y
Tabuchi
K
K
Nakata
Y
Y
Matsui
R
R
Sueyoshi
K
K
Narabayashi
I
I
D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery / Q000000981:diagnostic imaging* / Q000473:pathology; D011667:Pulmonary Veins / Q000000981:diagnostic imaging* / Q000473:pathology; D015898:Tomography Scanners, X-Ray Computed; D014057:Tomography, X-Ray Computed / Q000379:methods*