Free-breathing three-dimensional computed tomography of the lung using prospective respiratory gating: charge-coupled device camera and laser sensor device in an animal experiment.
OBJECTIVE
The aim was to investigate the feasibility and image quality of prospective respiratory gating for 3-D computed tomography (CT) of the lung.


METHODS
Eight anesthetized pigs underwent prospectively gated multidetector computed tomography using 2 devices: a charge-coupled device (CCD) camera and a laser sensor. The output signal of both gating devices was connected to the scanner instead of ECG unit. Inspiratory and expiratory images were obtained during "free-breathing" and analyzed in MPR mode for sharpness of bronchi, diaphragm and lung using a 4-point-score (1, excellent to 4, severe artifacts).


RESULTS
The CCD camera worked in all animals. Using the laser sensor, only 50% of expiratory scans could be acquired. All acquired images showed excellent sharpness (CCD camera vs. laser sensor) for trachea (1.1 +/- 0.3 vs. 1.3 +/- 0.5), bronchi (1.4 +/- 0.7 vs. 1.8 +/- 0.6), lung fissures (1.0 vs. 1.1 +/- 0.3), and lung parenchyma (1.0 +/- 0.2 vs. 1.4 +/- 0.6), and minor to major artifacts for diaphragm (1.5 +/- 0.8 vs. 2.0 +/- 1.0, P < 0.05) and pericardial lung structures (1.9 +/- 0.7 vs. 2.3 +/- 0.5).


CONCLUSIONS
High image quality for inspiratory and expiratory scans was achieved by free-breathing 3-D CT of the lung using noncontact prospective respiratory gating.
Zaporozhan
Julia
J
Department of Radiology, E010, German Cancer Research Center, Heidelberg, Germany. juliazapo@web.de
Ley
Sebastian
S
Unterhinninghofen
Roland
R
Saito
Yasuo
Y
Fabel-Schulte
Michael
M
Keller
Susanne
S
Szabo
Gabor
G
Kauczor
Hans-Ulrich
HU
D000818:Animals; D005240:Feasibility Studies; D021621:Imaging, Three-Dimensional; D007834:Lasers; D008168:Lung / Q000000981:diagnostic imaging* / Q000502:physiology; D009068:Movement; D010781:Photography / Q000295:instrumentation; D011857:Radiographic Image Interpretation, Computer-Assisted; D015656:Respiratory Mechanics; D013552:Swine; D014057:Tomography, X-Ray Computed / Q000379:methods*