The Quality of Reconstructed 3D Images in Multidetector-Row Helical CT: Experimental Study Involving Scan Parameters.
- Author:
Ji Hoon SHIN
1
;
Ho Kyu LEE
;
Choong Gon CHOI
;
Dae Chul SUH
;
Tae Hwan LIM
;
Weechang KANG
Author Information
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords: Computed tomography (CT), helical; Computed tomography (CT), three-dimensional; Computed tomography (CT), experimental study
- MeSH: Human; *Image Processing, Computer-Assisted; *Imaging, Three-Dimensional; Support, Non-U.S. Gov't; *Tomography, X-Ray Computed
- From:Korean Journal of Radiology 2002;3(1):49-56
- CountryRepublic of Korea
- Language:English
- Abstract: OBJECTIVE: To determine which multidetector-row helical CT scanning technique provides the best-quality reconstructed 3D images, and to assess differences in image quality according to the levels of the scanning parameters used. MATERIALS AND METHODS: Four objects with different surfaces and contours were scanned using multidetector-row helical CT at three detector-row collimations (1.25, 2.50, 5.00 mm), two pitches (3.0, 6.0), and three different degrees of overlap between the reconstructed slices (0%, 25%, 50%). Reconstructed 3D images of the resulting 72 sets of data were produced using volumetric rendering. The 72 images were graded on a scale from 1 (worst) to 5 (best) for each of four rating criteria, giving a mean score for each criterion and an overall mean score. Statistical analysis was used to assess differences in image quality according to scanning parameter levels. RESULTS: The mean score for each rating criterion, and the overall mean score, varied significantly according to the scanning parameter levels used. With regard to detector-row collimation and pitch, all levels of scanning parameters gave rise to significant differences, while in the degree of overlap of reconstructed slices, there were significant differences between overlap of 0% and of 50% in all levels of scanning parameters, and between overlap of 25% and of 50% in overall accuracy and overall mean score. Among the 18 scanning sequences, the highest score (4.94) was achieved with 1.25 mm detector-row collimation, 3.0 pitch, and 50% overlap between reconstructed slices. CONCLUSION: Comparison of the quality of reconstructed 3D images obtained using multidetector-row helical CT and various scanning techniques indicated that the 1.25 mm, 3.0, 50% scanning sequence was best. Quality improved as detector-row collimation decreased; as pitch was reduced from 6.0 to 3.0; and as overlap between reconstructed slices increased.
