Image quality from high-resolution CT of the lung: comparison of axial scans and of sections reconstructed from volumetric data acquired using MDCT.
OBJECTIVE
Our objective was to compare the image quality of reconstructed thin sections obtained from a 16-MDCT scanner with that of axial high-resolution CT scans of the same patient.


METHODS
Fifty consecutive patients referred for CT of the chest underwent 16-MDCT and, subsequently, axial high-resolution CT. The volumetric raw data from the MDCT scans were reconstructed into slices 2-mm thick using a high-spatial-frequency reconstruction algorithm. Two blinded reviewers independently rated the images from both methods for subjective image-quality criteria. The results were tested for statistical significance using Wilcoxon's signed rank test, and p values of less than 0.05 were considered significant. The effective dose for axial high-resolution CT and volumetric MDCT was calculated.


RESULTS
Motion artifacts were significantly more common on high-resolution CT scans than on reconstructed thin-section images (p < 0.001). The two methods differed significantly in lung attenuation (p = 0.008), mainly because of the presence of ground-glass opacities. The assessment of ground-glass attenuation was superior on axial high-resolution CT. The effective doses were 3.8 mSv for MDCT and 0.9 mSv for high-resolution CT.


CONCLUSIONS
Reconstructed high-resolution images generated from a single MDCT data acquisition are of comparable quality to images obtained using conventional axial high-resolution CT. However, contiguous MDCT is not recommended for diseases showing predominantly ground-glass patterns, because axial high-resolution CT delineates ground-glass attenuation significantly better.
Studler
Ueli
U
Department of Radiology, University Hospital Basel, Switzerland. studleru@tiscali.ch
Gluecker
Thomas
T
Bongartz
Georg
G
Roth
Jakob
J
Steinbrich
Wolfgang
W
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D016477:Artifacts; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*