Yun Shen MD, PhD, Abstract Co-Author: Nothing to Disclose

Jianying Li PhD, Presenter: Employee, General Electric Company

Akira Hagiwara MS, Abstract Co-Author: Employee, General Electric Company

Yan Gao MD, Abstract Co-Author: Nothing to Disclose

Makoto Gohno MSc, Abstract Co-Author: Employee, General Electric Company

Kun-cheng Li PhD, Abstract Co-Author: Nothing to Disclose

Jingmin Liao, Abstract Co-Author: Nothing to Disclose

Dynamic CT angiography (CTA) and Volume CT perfusion were obtained by using one volume axial scan on the 64 row 40mm Volume CT (VCT), and to improve z resolution of MPR image is important for dynamic CTA image quality. The purpose of this paper is to propose and assess new algorithm by using combination of cone beam reconstruction algorithm and overlapping technique for improvement of high resolution MPR image.

The new axial reconstruction algorithm with high z resolution was constructed by using combination of cone beam reconstruction algorithm and overlapping technique. The slit phantom and clinical dynamic CTA was used to assess new axial reconstruction algorithm on the 64 row Volume CT scanner (GE LightSpeed VCT, 64x0.625mm=40mm, 0.35s/r). Next three overlapping rate was used: 1) 100% (non overlapping): 64ix0.625mm; 2) 50% overlapping: 128ix0.625mm; 3) 25% overlapping: 256ix0.625mm. The two estimation methods was used for z-resolution assessment: 1) SD measurement for z direction profile; 2) Difference (D) of peak and down.

In qualitative analysis of slit phantom, for 100% (64i), 50% (128i) and 25% (256i) overlapping, z-resolution (SD) is 210.3, 257.6 (22.5%) and 261.9 (24.5%), respectively; z-resolution (D) is 565, 654 (15.8%) and 671 (18.8%), respectively. In qualitative analysis of dynamic patient CTA data with transient ischemic attack (TIA), for 100% (64i), 50% (128i) and 25% (256i) overlapping, z-resolution (SD) is 21.9, 23.5 (6.9%) and 24.2 (10.3%), respectively; z-resolution (D) is 72, 85 (18.1%) and 88 (22.2%), respectively.

From qualitative analysis results of slit phantom and dynamic patient CTA, we conclude that proposed new reconstruction algorithm by using combination of cone beam algorithm and overlapping technique can provide high z-resolution dynamic CTA MPR image on the volume axial scan.

This research about new algorithm is very important to provide high quality dynamic CTA (angiography) image and volume CTP (Perfusion) image on the one volume axial scan.

Shen, Y, Li, J, Hagiwara, A, Gao, Y, Gohno, M, Li, K, Liao, J, New Axial Volume Reconstruction Algorithm for High Resolution MPR Image by Using Combination of 3D Back Projection (Cone Beam) Reconstruction and Overlapping Technique on the 40mm Volume CT (VCT) Dynamic Axial Scan.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5014385.html