Sebastian Winklhofer MD, Presenter: Nothing to Disclose

Fabian Morsbach, Abstract Co-Author: Nothing to Disclose

Emanuel Benninger MD, Abstract Co-Author: Nothing to Disclose

Stefan Rahm MD, Abstract Co-Author: Nothing to Disclose

Steffen Ross MD, Abstract Co-Author: Nothing to Disclose

Bernhard Jost MD, Abstract Co-Author: Nothing to Disclose

Christian Spross MD, Abstract Co-Author: Nothing to Disclose

Paul Stolzmann MD, Abstract Co-Author: Nothing to Disclose

Michael J. Thali MD, Abstract Co-Author: Nothing to Disclose

Hatem Alkadhi MD, Abstract Co-Author: Nothing to Disclose

Roman Guggenberger, Abstract Co-Author: Nothing to Disclose

To assess the value of monoenergetic extrapolations from dual-energy computed tomography (DECT) and standard filtered back projections (FBP) from single-energy computed tomography (SECT) compared to a new iterative frequency split-normalized (IFS) metal artifact reconstruction (MAR) algorithm for artifact reduction in internally fixated humeral fractures.

In this cadaveric study, artifacts in seven internally fixated human proximal humeral fractures of five subjects were examined with SECT and DECT. Postprocessing included routinely used FBP algorithm, a new IFS-MAR algorithm, and monoenergetic extrapolation of DECT images. Image analysis included quantitative assessment of image artifacts (HU measurements) as well as evaluation of image quality and osteosynthesis material and visualization of screw position in FBP, IFS-MAR, and DECT using a five-point Likert scale.

HU values of streak artifacts were significantly (P < .05) different between FBP (115.7±222.4) and IFS-MAR (68.7±106.3), and between FBP and monoenergetic DECT (10.1±146.1). Between IFS-MAR and DECT no significant differences were detected (P = .30). Artifact scores improved significantly from FBP (3.9) to IFS-MAR (2.0; P < .001) and DECT (2.6; P < .05), whereas no significant differences were seen between IFS-MAR and DECT (P = .10). Visualization scores of osteosynthesis material differed significantly (P < .05) between FBP (2.9) and IFS-MAR (2.3) and between IFS-MAR and DECT (1.4). Screw position of 57/57 screws was identically rated in FBP and IFS-MAR, but different between IFS-MAR and DECT in 11 cases, with a subjectively better visualization in DECT.

IFS-MAR algorithm in SECT as well as monoenergetic extrapolations from DECT allow for an improved image quality, a reduction of artifacts and better assessment of screw-position compared to standard FBP in SECT.

Both, dual-energy CT and a newly applied iterative frequency split-normalized metal artifact reconstruction algorithm for CT are promising techniques for metal artifact reduction in internally fixated

Winklhofer, S, Morsbach, F, Benninger, E, Rahm, S, Ross, S, Jost, B, Spross, C, Stolzmann, P, Thali, M, Alkadhi, H, Guggenberger, R, CT Metal Artifact Reduction in Internally Fixated Proximal Humeral Shaft Fractures: Comparison between Monoenergetic Extrapolation of Dual Energy and Iterative Artifact Reduction Algorithms.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13018926.html