华西医院李真林 Optimal scanning collimation for segmental bronchi: experimental study with low-dose helical CT

Sichuan Da Xue Xue Bao Yi Xue Ban. 2004 Jan;35（1）:120-2.

[Optimal scanning collimation for segmental bronchi: experimental study with low-dose helical CT].

[Article in Chinese]

Yu JQ1, Yang ZG, Li ZL, Chen X.

Author information

1Department of Radiology, West China Hospital, Sichuan University, Chengdu 610041, China.

Abstract

OBJECTIVE:

To evaluate the effects of low-dose helical CT with different scanning collimation on the visualization of segmental bronchi and to determine the optimal scanning collimation in CT screening for early central lung cancer.

METHODS:

Forty healthy volunteers were randomly assigned to undergo the low-dose helical CT at 120 kVp, 50 mA, 0.75 s and pitch 1. One group （n = 20） underwent the sequential subsection scan of chest with the collimation of 10 mm for the apical and basilar zone, and of 8 mm and 5 mm for the hilar zone. The other （n = 20） went through CT scan with 10 mm collimation of the whole lung. The visualizations of lobar, segmental bronchi were compared at different collimations. ANOVA and multiple comparison were performed.

RESULTS:

The visualization of segmental bronchi on low-dose scan at 10 mm collimation was 60%, being lower than that at 8 mm （88%） or 5 mm （91%） collimation （P < 0.01）. The segmental bronchi of right upper lobe were easily identified at collimation of 10 mm （82%）, 8 mm （96%） and 5 mm （98%）, as well as those of left upper lobe at 10 mm （83%）, 8 mm （95%） and 5 mm （97%）, whereas those of lingular lobe were difficultly identified at 10 mm （30%）, 8 mm （60%） and 5 mm （70%）.

CONCLUSION:

The lobar and segmental bronchi were visualized reliably by CT with 50 mA and 8 mm collimation, and therefore the sequential subsection scan of chest divided into three zones can be adapted to CT screening for early lung cancer.

PMID: 14981835