1. Zentrum f. Medizinische Physik u. Biomedizinische Technik & MR-Hochfeld-Zentrum MR-Microscopy of small specimen on a Human 7T-Scanner Andreas Berg A.Berg, MR-Center 06.04.2011 Quality control spatial resolution 1.) Paraplegia model in rat spine 2.) osteoarthritis: cartilage bone intervert. Disc 3.) teeth and dental composites Methodology: hardware

2. MR-microscopy insert on 7T scanner: Standard whole body scanner: Phantoms: test structures d < 100 µm Results Quality control:Spatial Resolution Phantoms: Test structures d > 1000 µm A. Berg, Deutsches Patentamt, München, DE19904635, 19.08.1999 1,5 cm

3. First results: Quality Control: spatial Resolution Silicon grid in Silicon oil MR-microscopic images of Silicon grid sets in Silicon oil (finest: a/2 = 32 µm) Left: sagittal view at increased SNR (32 averages ) Top: enlarged area trace of profile is indicated Bottom: profile indicating modulation depth Right: sagittal view for a short protocol Voxel size: 50,9 x 25,4 x 200 µm 3 !!! = 2,6 10 -4 mm 3 = 0,26 10 -9 l < 10 -3 Clinical Voxel size (500 x 500 x 2000 µm) TM = 1,5 min SNR = 3,15 TM = 87 min SNR = 16 A. Berg et al. MR-MICROSCOPY ON A HUMAN 7T- SCANNER; ISMRM/ESMRMB 2010, progr nr. 1048,

4. MR-microscopy vs. histology: Osteoarthritis MR-microscopy: A. Berg; Samples and referencing: S. Domayer, J. Hofstätter Univ. klinik f. Orthopädie

5. Osteoarthritis cartilage-bone interface: MR-microscopy vs histological staining Histologic staining: Safranin-O MR-microscopy: TE = 8 ms Voxel: 96 x 59 x 240 µm 3 MR-microscopy vs histology: Intact tissue after measurement No damage due to cutting No staining necessary (T2, T1, Diffusivity) Low effort, Low preparation - and measurement time 1.) Healthy cartilage (lateral condyle of the knee): Homogeneous, thick cartilage layer trabecular network structure A. Berg, A. Potthast, P. Starewicz, S. Domayer, J. G. Hofstaetter; MR-Microscopy on a human MR-7T Scanner: Methodology and application to medial osteoarthritic samples of the Knee. ECR 2011 Vienna

6. MR-Microscopy vs. histology Size: 250 µm - 50 µm Small degradation areas below the surface Presumably: areas of fibrillation and loss of proteoglycane 8 mm osteoarthritic cartilage (medial condyle of the knee): 5 A. Berg, A. Potthast, P. Starewicz, S. Domayer, J. G. Hofstaetter; MR-Microscopy on a human MR-7T Scanner: Methodology and application to medial osteoarthritic samples of the Knee. ECR 2011 Vienna Voxel size = 51 x 51 x 240 µm 3 < 10 -3 clinical MRI voxel size (500 x 500 x 2000 µm 3 ) TSE: 3D-MTX: 256x 256 x 47 TE = 8.2 ms, TR = 2.3 s TM = 16 min MR-microscopy:

7. Small degradation areas below the surface Presumably: areas of fibrillation and loss of proteoglycane osteoarthritic cartilage (medial compartment of the knee): MR-Microscopy vs Histology A. Berg, A. Potthast, P. Starewicz, S. Domayer, J. G. Hofstaetter; MR-Microscopy on a human MR-7T Scanner: Methodology and application to medial osteoarthritic samples of the Knee. ECR 2011 Vienna 4 mm

8. 3D-multislicing Pulse sequence: Berg_TSE Voxel: 51 x 51 x 240 µm 3 3D-MTX: 256x 256 x 47 TM = 16 min A. Berg, A. Potthast, P. Starewicz, S. Domayer, J. G. Hofstaetter; MR-Microscopy on a human MR-7T Scanner: Methodology and application to medial osteoarthritic samples of the Knee. ECR 2011 Vienna 13 mm