Lukas Filli MD, Presenter: Nothing to Disclose

Magda Marcon MD, Abstract Co-Author: Nothing to Disclose

Bernhard Georg Scholz PhD, Abstract Co-Author: Employee, Siemens AG

Maurizio Calcagni, Abstract Co-Author: Nothing to Disclose

Thomas Pfammatter MD, Abstract Co-Author: Nothing to Disclose

Gustav Andreisek MD, Abstract Co-Author: Grant, Holcim Ltd Grant, Siemens AG Speaker, Mepha Pharma AG Speaker, Guerbet SA Travel support, Guerbet SA Consultant, Otsuka Holdings Co, Ltd Travel support, Otsuka Holdings Co, Ltd Institutional Research Grant, Bayer AG Institutional Research Grant, Guerbet AG Institutional research collaboration, Siemens AG Institutional research collaboration, Koninklijke Philips NV Speaker, General Electric Company Speaker, Koninklijke Philips NV Speaker, Siemens AG

Roman Guggenberger, Abstract Co-Author: Nothing to Disclose

In the past two years, flat-detector computed tomography (CT) has gained great interest for imaging small anatomic structures of the appendicular skeleton. However, flat-detector CT imaging can be significantly impaired by metal artifacts induced by orthopedic hardware. The aim of this study was to evaluate a new prototype metal artifact correction algorithm for flat-detector CT systems.

IRB approval was waived. An experienced hand surgeon inserted commercially available scaphoid fixation screws into six cadaveric human specimens to fix artificially induced scaphoid fractures. Flat-detector CT was performed using an angiographic unit (Artis Zeego multiaxis system, Siemens Medical Solutions, Forchheim, Germany). From the raw data, images were reconstructed not using and using the prototype metal artifact correction algorithm. Two independent radiologists analyzed quantitatively the amount of artifacts and qualitatively the visibility of (anatomic) structures. For comparison, Wilcoxon signed-rank test were used. A p-value of < 0.05 was considered to indicate statistically significant differences. Intra-class-correlation was calculated for inter-observer agreement.

The overall intra-class-correlation was 0.85. The artifact-related noise around the scaphoid fixation screws was significantly lower on the images corrected with the prototype metal artifact reduction algorithm (p < 0.001). Qualitative analyses showed significantly fewer artifacts (p < 0.001), better visible screw contour (p < 0.001), and more clearly defined fracture lines (p < 0.01) on the corrected images.

The new algorithm for FDCT systems significantly reduces metal artifacts and improves visibility of relevant (anatomic) structures.

The prototype metal artifact correction algorithm may facilitate intra- and postoperative follow-up imaging.

Filli, L, Marcon, M, Scholz, B, Calcagni, M, Pfammatter, T, Andreisek, G, Guggenberger, R, Evaluation of a New Prototype Correction Algorithm to Reduce Metal Artifacts in Flat-detector Computed Tomography – An Ex-vivo Study.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14003281.html