Experimental study about the effect of different scan parameters and post-processing methods of multi-detector CT on metallic artifacts / 实用放射学杂志

ABSTRACT

Objective To explore the effect of multi-detector computed tomography (MDCT)scan parameters and imaging post-processing methods on metallic artifacts,so as to achieve the perfection in reduction of artifacts caused by metallic implants.Methods Water phantom with titanium alloy steel plate was scanned under MDCT with alternating scan parameters including tube voltage, tube current,pitch and focal spot.The areas of image artifacts were measured and correlated with the scan parameters.Another 1 5 postoperative patients with vertebral implantation scaned with the conventional scan parameters were also included in the study.Ima-ging post-processing including multi-planar reconstruction (MPR),window width and level adjustment,and volume rendering tech-nique (VRT)was performed by using optimized and conventional methods,respectively,and then the image quality was evaluated. Results The areas of image artifacts under the differnt tube voltage,pitch,and focal spot were statistically different.With the in-crease of the tube voltage or the decrease of the pitch,the area of image artifacts decreased gradually.The area of image artifacts scanned with the small focal spot was smaller than the large one.There was no significant difference for the area of image artifacts scanned with the different tube currents.The metallic artifacts decreased by using the soft tissue algorithm (Kernel B40f)in the bone window reconstruction,wide windows (2 000 HU window width,600 HU window level)in observing,and VRT.Conclusion Selection of appropriate MDCT scan parameters and imaging post-processing methods can reduce the metal artifacts,improve the image quality and diagnosis.