Yiannis Kyriakou, Presenter: Nothing to Disclose

Robert Michael Lapp, Abstract Co-Author: Employee, VAMP GmbH, Erlangen, Germany

Christine Niebler MS, Abstract Co-Author: Nothing to Disclose

Daniel Prell, Abstract Co-Author: Nothing to Disclose

Maria Henke Dipl Eng, Abstract Co-Author: Nothing to Disclose

Willi A. Kalender PhD, Abstract Co-Author: Consultant, Siemens AG Founder, VAMP GmbH Scientific Advisor, VAMP GmbH Shareholder, VAMP GmbH

To provide a flexible and vendor-independent image reconstruction station for flat-detector CT (FD-CT) with a wide range of artifact correction methods aimed at intraoperative imaging.

An image reconstruction platform was developed with the aim to process different flat-detector raw-data formats. It uses a Feldkamp-type reconstruction algorithm including Parker weighting supporting partial scans. It integrates a multitude of pre- and post-processing correction algorithms. The options of empirical and analytical cupping correction are provided for pre-correction of polychromatic data. Misalignment and truncation correction algorithms were integrated into the workflow. To deal with increased scatter artifacts in FD-CT a scatter suppression based on physical scatter modelling was included. To improve image quality near metallic implants the system includes a raw-data based metal artifact reduction algorithm. Furthermore, methods for dose reduction such as multi-dimensional adaptive filtering were included. Correction options can be switched off or on by expert users for testing and educational purposes. For an exemplary test (Axiom Artis, Siemens Medical Solutions, Forchheim, Germany) we evaluated the performance of the reconstruction platform with respect to the its integration ability and image quality.

Image reconstruction times of ≤2 min for a 512³ volume from typ. 500 projections were achieved on a standard PC hardware including region of interest reconstruction. Water pre-correction and scatter suppression provided homogeneous water phantom images. Metal artifacts were suppressed with an additional computational effort of only 3-5% of total reconstruction time. The built-in DICOM services provide a seamless integration into the clinical and/or intraoperative workflow in a heterogeneous hardware environment.

The developed vendor-independent reconstruction platform meets the need for an efficient, fast and extensible system that can be used for multiple applications in the intraoperative FD-CT workflow.

Improved image quality in an integrated FD-CT reconstruction environment is essential for 3D intraoperative imaging.

Kyriakou, Y, Lapp, R, Niebler, C, Prell, D, Henke, M, Kalender, W, Development and Integration of Correction Methods in a Vendor-independent Intraoperative Flat-Detector CT Image Reconstruction Platform.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5011876.html