Image quality improvement in submillisievert computed tomographic colonography using a fast 3-dimensional noise reduction method.
OBJECTIVE
The objective of this study was to evaluate the image quality in submillisievert computed tomographic colonography (CTC) images using a structure preserving diffusion denoising method.


METHODS
Image quality was compared before and after denoising in 31 patients. One hundred twenty-kilovolt, 30-mAs prone CTC scans were used as reference and compared with submillisievert 140-kV, 10-mAs supine scans. Two readers assessed 2-dimensional and endoluminal image quality. The image noise and the signal-to-noise ratio were measured.


RESULTS
After denoising, image quality scores improved in both supine series and prone series (P < 0.0001), with the submillisievert denoised images being equal to or better than the native prone reference images. In both the supine images and the prone images, the noise was reduced by a factor of 2 and the signal-to-noise ratio was significantly higher (P < 0.001). The signal-to-noise ratio in the denoised submillisievert images was higher than those in the native prone images (P < 0.001).


CONCLUSIONS
The structure preserving diffusion denoising method preserves the image quality in submillisievert CTC images compared with the native 30-mAs reference images.
From the *Virtual Colonoscopy Teaching Centre, Hooglede; †Department of Radiology, Stedelijk Ziekenhuis Roeselare, Roeselare, Belgium; ‡Vital Images, Inc, Minnetonka, MN.
Stefaan S
SS
Gryspeerdt
Pascal
P
Salazar
Philippe
P
Lefere
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D016477:Artifacts; D023881:Colonography, Computed Tomographic / Q000379:methods*; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D059629:Signal-To-Noise Ratio