Ahi Sema Issever MD, Presenter: Nothing to Disclose

Gerd Diederichs MD, Abstract Co-Author: Nothing to Disclose

Patrik Rogalla MD, Abstract Co-Author: Nothing to Disclose

Bernd K. Hamm MD, Abstract Co-Author: Nothing to Disclose

Axel Lange, Abstract Co-Author: Nothing to Disclose

Michael Harwardt, Abstract Co-Author: Nothing to Disclose

Manfred P. Hentschel, Abstract Co-Author: Nothing to Disclose

Bernd Mueller, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

Chapman et al. introduced a novel X-ray modality in 1997 – diffraction enhanced imaging (DEI) – which expanded the performance of X-ray imaging by utilizing not only the absorption properties of X-rays but also the refraction and scatter rejection (extinction) properties of the object being scanned. Especially for the field of cartilage imaging DEI promises to be a powerful alternative to currently available conventional radiography or magnetic resonance imaging.The disadvantage of radiographic imaging – such as used in previous cartilage DEI studies – though is that it generates a superimposed image of the object being scanned, merging the data of the whole object volume into a single two-dimensional image. In order to generate an image that gives a true account of the three-dimensional structure of the object being scanned tomographic techniques need to be used.

In our current study we implemented tomographic DEI on a cartilage sample (2.6 mm diameter). The cartilage specimen was placed in a monochromatic (20 keV) and parallel beam between two single Si (111) crystals. The pixel size was about 4 µm. Filtered back projection was used for data analysis.

In the images obtained “hypodense” areas within the homogenous main cartilage substance are depicted. Whether or not these “hypodense” areas represent the chondrocyte lacunes – which we assume – our images prove that substructural variations in cartilage can be visualized with tomographic DEI. In addition upon sagittal reconstruction of our data set we can identify more vertically oriented hypodensities in about two thirds of the cartilage.

We hypothesize that these vertically oriented structures are the DEI equivalent of the deep cartilage zone known from Benninghoff’s cartilage model he proposed in 1925.

To our knowledge, this is the first study to prove that substructures of articular cartilage can be depicted nondestructively and most importantly without overlap using high-resolution DEI tomography.

Issever, A, Diederichs, G, Rogalla, P, Hamm, B, Lange, A, Harwardt, M, Hentschel, M, Mueller, B, et al, , et al, , First High-Resolutional DEI Tomography Images of Cartilage.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5012799.html