Goetz Hannes Welsch MD, Presenter: Nothing to Disclose

Tallal Charles Mamisch MD, Abstract Co-Author: Consultant, Siemens AG

Lukas Zak, Abstract Co-Author: Nothing to Disclose

Sebastian Apprich, Abstract Co-Author: Nothing to Disclose

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

Siegfried Trattnig MD, Abstract Co-Author: Nothing to Disclose

Recently, the widely used 3D Double-Echo Steady-State (DESS) sequence was reported to enable, in addition to the morphological information it provides, the generation of biochemical T2 maps in one hybrid sequence. The aim of this study was to use this new DESS-T2d approach to assess the morphological Magnetic resonance Observation of Cartilage Repair Tissue (MOCART) score, as well as biochemical T2 values in patients after matrix-associated autologous chondrocyte transplantation (MACT) of the knee. Furthermore, to correlate this new hybrid approach to standard morphological sequences as well as to standard T2 mapping.  

Fifty consecutive MR scans during clinical routine standard follow-up intervals at 3.0 Tesla in patients (36.1±9.3 years) after MACT of the knee joint were prospectively included. MOCART scoring was prepared by i) a set of standard MR sequences and ii) the morphological images of the new DESS-T2d sequence. T2 relaxation times were assessed by region-of-interest analysis on basis of i) a standard multi-echo spin-echo (MSME) sequence and ii) the biochemical T2d images of the DESS-T2d sequence. Analysis-of-variance and Pearson correlation was performed.

The MOCART score correlated (0.945; p<0.001) significantly as assessed with standard morphological sequences (68.8±13.2) and the morphological images of the DESS T2d sequence (68.7±12.6). T2 and T2d relaxation times (ms) were comparable in between the control cartilage (T2: 52.5±11.4; T2d: 46.6±10.3) and the repair tissue (T2: 54.4±11.4; T2d: 47.5±13.0) (T2: p=0.157; T2d: p=0.589). As expected, T2d values were lower than the MSME-T2 values, however both functional relaxation times correlated significantly (Pearson:0.429; p<0.001).

Comparable information on the repair tissue could be achieved at enormous time-savings, with ~20 minutes for the standard sequences and ~5 minutes for the hybrid DESS-T2d sequence. Hence the presented approach provides the possibility to combine morphological and biochemical MRI in one fast 3D sequence, and thus, may attract for the clinical use of biochemical MRI.

To combine morphological and biochemical cartilage imaging in one hybrid sequence saves acquisition time and attracts for functional imaging in a clinical background.

Welsch, G, Mamisch, T, Zak, L, Apprich, S, Marlovits, S, Trattnig, S, Hybrid Morphological and Biochemical T2 Evaluation of Cartilage Repair Tissue, Based on a Recently Described Double Echo at Steady State (DESS-T2d) Approach.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9005009.html