Low-dose multislice spiral computed tomography in acute lung injury: animal experience.
OBJECTIVE
To compare low-dose multislice spiral CT (MSCT) with a standard protocol for the evaluation of acute lung injury (ALI) in an animal model.


METHODS
Eleven healthy intubated pigs (weight: 32.4 kg +/- 1.9 kg) underwent lung lavage to induce experimental lung injury before CT examinations. Scanning was performed using a MSCT-technique. The entire chest was scanned using a thin-collimated protocol (140 kV; 100 mAs). The examinations were performed in inspiratory breath-hold in supine and in prone positions. Scanning was repeated after reduction of the tube current time product down to 20 mAs. All other parameters were kept constant. Subjective image quality was rated using a six-point scale by three experienced radiologists. In addition, objective criteria, based on signal to noise measurements, were assessed. Finally, the extent, localization, and distribution of lung opacities was analyzed using dedicated postprocessing software.


RESULTS
Subjective image quality was rated inferior in the low-dose MSCT-examinations (prone position: 2.1 vs. 3.0; supine position: 1.5 vs. 2.5). Hence, pixel noise was nearly doubled. However, exact information about the extent, localization and distribution of lung opacities was provided. There were no statistically significant differences between standard and low-dose MSCT in this respect.


CONCLUSIONS
In the animal experiments, low-dose MSCT-scanning did not impair the diagnostic accuracy in ALI, offering an advantageous reduction of radiation exposure.
Wildberger
Joachim E
JE
Department of Diagnostic Radiology, University Hospital, University of Technology (RWTH), Aachen, Germany. wildberg@rad.rwth-aachen.de
Max
Martin
M
Wein
Berthold B
BB
Mahnken
Andreas H
AH
Weiss
Claudia
C
Dembinski
Rolf
R
Katoh
Marcus
M
Schaller
Stefan
S
Rossaint
Rolf
R
Günther
Rolf W
RW
D000818:Animals; D023421:Models, Animal; D011829:Radiation Dosage; D012128:Respiratory Distress Syndrome / Q000000981:diagnostic imaging*; D013552:Swine; D036542:Tomography, Spiral Computed / Q000379:methods*