Kaiss Shanneik PhD, Presenter: Nothing to Disclose

Marc Kachelriess PhD, Abstract Co-Author: Nothing to Disclose

Willi A. Kalender PhD, Abstract Co-Author: Nothing to Disclose

Assessment of various cardiac reconstruction algorithms available on different CT systems with respect to temporal resolution, image quality and artifact content.

The following cone-beam (CB) reconstruction algorithms were assessed: multi-slice cardio interpolation MCI algorithm (neglecting cone angle in MSCT), the advanced single-slice rebinning cardio interpolation ASSR (tilted-slice-based CB algorithm for moderate cone angles) and the extended parallel backprojection EPBP (Feldkamp-based wide cone angle CB algorithm). A cardiac phantom capable of simulating motion was used to move a 100 µm tungsten sphere with motion rates of 40 - 120 min-1. Data were simulated with standard cardiac protocols using various CT systems. Assessment of temporal resolution was based on the full volume at half maximum (FVHM) of the point spread function of the moving sphere. This measure is used to quantify the temporal resolution of the reconstruction algorithm and the spatial resolution of the CT system as well as the artifact content in the reconstructed image.

The performance of the ASSR algorithm was better compared to the MCI on a 4-slice CT (Volume Zoom, Siemens Medical Solutions) system (FVHM improvement of 12%) indicating a better image quality and a reduction in image artifacts. By keeping the spatial resolution of the systems equal, the improvement can be attributed to the better temporal resolution of the ASSR algorithm. Comparison of ASSR and EPBP yielded significant image quality improvements for the EPBP algorithm (FVHM improvement 18%). EPBP showed the least image artifact content throughout the range of heart rates.

From our study it was shown that the EPBP algorithm provided the best image quality and outperformed the ASSR algorithm that was used previously.

W.A.K.: Consultant to Siemens Medical Solutions

Shanneik, K, Kachelriess, M, Kalender, W, Performance Assessment of Various Cardiac Image Reconstruction Algorithms in Multi-slice Spiral CT.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4417488.html