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DIFFUSION MRI MODELS FOR CARTILAGE: BEYOND THE DIFFUSION TENSOR [Meeting Abstract]

Ferizi, U; Rossi, I; Glaser, C; Bencardino, J; Raya, J
ISI:000373538800502
ISSN: 1522-9653
CID: 2090532

Understanding 3D TSE Sequences: Advantages, Disadvantages, and Application in MSK Imaging

Glaser, Christian; D'Anastasi, Melvin; Theisen, Daniel; Notohamiprodjo, Mike; Horger, Wilhelm; Paul, Dominik; Horng, Annie
Three-dimensional (3D) turbo-spin echo (TSE) sequences have outgrown the stage of mere sequence optimization and by now are clinically applicable. Image blurring and acquisition times have been reduced, and contrast for T1-, T2-, and moderately T2-weighted (or intermediate-weighted) fat-suppressed variants has been optimized. Data on sound-to-noise ratio efficiency and contrast are available for moderately T2-weighted fat-saturated sequence protocols. The 3-T MRI scanners help to better exploit isotropic spatial resolution and multiplanar reformatting. Imaging times range from 5 to 10 minutes, and they are shorter than the cumulative acquisition times of three separate orthogonal two-dimensional (2D) sequences. Recent suggestions go beyond secondary reformations by using online 3D rendering for image evaluation. Comparative clinical studies indicate that the diagnostic performance of 3D TSE for imaging of internal derangements of joints is at least comparable with conventional 2D TSE with potential advantages of 3D TSE for small highly curved structures. But such studies, especially those with direct arthroscopic correlation, are still sparse. Whether 3D TSE will succeed in entering clinical routine imaging on a broader scale will depend on further published clinical evidence, on further reduction of imaging time, and on improvement of its integration into daily practice.
PMID: 26583360
ISSN: 1098-898x
CID: 2033732

Topographic deformation patterns of knee cartilage after exercises with high knee flexion: an in vivo 3D MRI study using voxel-based analysis at 3T

Horng, Annie; Raya, J G; Stockinger, M; Notohamiprodjo, M; Pietschmann, M; Hoehne-Hueckstaedt, U; Glitsch, U; Ellegast, R; Hering, K G; Glaser, C
OBJECTIVES: To implement a novel voxel-based technique to identify statistically significant local cartilage deformation and analyze in-vivo topographic knee cartilage deformation patterns using a voxel-based thickness map approach for high-flexion postures. METHODS: Sagittal 3T 3D-T1w-FLASH-WE-sequences of 10 healthy knees were acquired before and immediately after loading (kneeling/squatting/heel sitting/knee bends). After cartilage segmentation, 3D-reconstruction and 3D-registration, colour-coded deformation maps were generated by voxel-based subtraction of loaded from unloaded datasets to visualize cartilage thickness changes in all knee compartments. RESULTS: Compression areas were found bifocal at the peripheral medial/caudolateral patella, both posterior femoral condyles and both anterior/central tibiae. Local cartilage thickening were found adjacent to the compression areas. Significant local strain ranged from +13 to -15 %. Changes were most pronounced after squatting, least after knee bends. Shape and location of deformation areas varied slightly with the loading paradigm, but followed a similar pattern consistent between different individuals. CONCLUSIONS: Voxel-based deformation maps identify individual in-vivo load-specific and posture-associated strain distribution in the articular cartilage. The data facilitate understanding individual knee loading properties and contribute to improve biomechanical 3 models. They lay a base to investigate the relationship between cartilage degeneration patterns in common osteoarthritis and areas at risk of cartilage wear due to mechanical loading in work-related activities. KEY POINTS: * 3D MRI helps differentiate true knee-cartilage deformation from random measurement error * 3D MRI maps depict in vivo topographic distribution of cartilage deformation after loading * 3D MRI maps depict in vivo intensity of cartilage deformation after loading * Locating cartilage contact areas might aid differentiating common and work-related osteoarthritis.
PMID: 25595640
ISSN: 1432-1084
CID: 1598762

Feasibility of in vivo diffusion tensor imaging of articular cartilage with coverage of all cartilage regions

Raya, Jose G; Dettmann, Eike; Notohamiprodjo, Mike; Krasnokutsky, Svetlana; Abramson, Steven; Glaser, Christian
OBJECTIVES: To investigate the value of diffusion tensor imaging (DTI) of articular cartilage to differentiate healthy from osteoarthritis (OA) subjects in all cartilage regions. METHODS: DTI was acquired sagittally at 7 T in ten healthy and five OA (Kellgren-Lawrence grade 2) subjects with a line scan diffusion tensor sequence (LSDTI). Three healthy volunteers and two OA subjects were examined twice to assess the test-retest reproducibility. Averaged mean diffusivity (MD) and fractional anisotropy (FA) were calculated in each cartilage region (femoral trochlea, lateral and medial femoral condyles, patella, and lateral and medial tibia). RESULTS: The test-retest reproducibility was 2.9 % for MD and 5.6 % for FA. Averaged MD was significantly increased (+20 %, p < 0.05) in the OA subjects in the lateral femoral condyle, lateral tibia and the femoral trochlea compartments. Averaged FA presented a trend of lower values in the OA subjects (-12 %), which was only significant for the lateral tibia. CONCLUSIONS: In vivo DTI of articular cartilage with coverage of all cartilage regions using an LSDTI sequence is feasible, shows excellent reproducibility for MD and FA, and holds potential for the diagnosis of OA. KEY POINTS: * DTI of articular cartilage is feasible at 7 T in all cartilage regions * DTI of articular cartilage can potentially differentiate healthy and OA subjects.
PMID: 24816930
ISSN: 0938-7994
CID: 978812

Assessment of therapeutic response in ankylosing spondylitis patients undergoing anti-tumour necrosis factor therapy by whole-body magnetic resonance imaging

Karpitschka, Martina; Godau-Kellner, Patrizia; Kellner, Herbert; Horng, Annie; Theisen, Daniel; Glaser, Christian; Brandlhuber, Bernhard; Reiser, Maximilian; Weckbach, Sabine
OBJECTIVES/OBJECTIVE:Multifocal musculoskeletal inflammation is common in ankylosing spondylitis (AS) and is effectively treated by expensive anti-TNF (tumour necrosis factor) therapy. This study evaluated assessment of response by whole-body (WB) MRI compared with clinical assessment in AS patients during etanercept therapy. METHODS:Ten patients with AS underwent a 12-month therapy with etanercept. Clinical markers were monitored [Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and C-reactive protein (CRP)] and patients underwent WBMRI (1.5 T, STIR and T1-weighted) at three different time points (0, 26 and 52 weeks). WBMRI was evaluated and correlated with clinical scores. RESULTS:The BASDAI index decreased under therapy from 5.5 ± 0.5 (week 0) to 1.7 ± 0.5 (week 52, P < 0.05). CRP declined from 15.7 ± 2.2 mg/dl (week 0) to 0.9 ± 0.9 mg/dl (week 52, P < 0.05). In WBMRI, the sum of all lesions showed a significant decrease from week 0 (38.9 ± 3.4) to week 52 (2.2 ± 0.9, 94.3 % reduction). WBMRI detected more areas of synovitis and enthesitis than clinical examination alone. CONCLUSIONS:AS activity significantly decreased under etanercept therapy, which was proven by clinical examination and WBMRI. WBMRI detected more inflammatory lesions than clinical examination alone. The results suggest that WBMRI improves the detection of inflammatory changes and the assessment of their course under therapy. KEY POINTS/CONCLUSIONS:• Multifocal musculoskeletal inflammation in AS is effectively treated by anti-TNF therapy. • Inflammatory lesions can be assessed by clinical examination and whole-body MRI. • AS activity significantly decreased under therapy as shown by WBMRI/clinical examination. • WBMRI detected more inflammatory lesions than clinical examination alone. • WBMRI improves detection of inflammatory changes and may help evaluation of therapy.
PMID: 23494493
ISSN: 1432-1084
CID: 3339502

Diffusion-Tensor Imaging of Human Articular Cartilage Specimens with Early Signs of Cartilage Damage

Raya, Jose G; Melkus, Gerd; Adam-Neumair, Silvia; Dietrich, Olaf; Mutzel, Elisabeth; Reiser, Maximilian F; Putz, Reinhard; Kirsch, Thorsten; Jakob, Peter M; Glaser, Christian
Purpose: To assess the use of diffusion-tensor (DT) imaging of articular cartilage to detect and grade early cartilage damage in human specimens with early signs of cartilage damage. Materials and Methods: This study was approved by the institutional review board. Forty-three cartilage-on-bone samples drilled from 21 human patellae were examined with 17.6-T magnetic resonance (MR) imaging and a diffusion-weighted spin-echo sequence (spatial resolution, 50 x 100 x 800 mum). Subsequently, samples underwent histologic analysis with safranin O staining. Cartilage damage on safranin O histologic slides was quantified with Osteoarthritis Research Society International (OARSI) grades; grades ranged from 0 (healthy) to 6 (bone remodeling). Maps of longitudinal diffusivity (lambda(l)), transverse diffusivity (lambda(t)), mean diffusivity (MD), and fractional anisotropy (FA) were calculated. Cartilage was segmented, and region of interest (ROI) analysis was performed and compared with histologic findings. Significant differences in MR parameters between the OARSI groups were assessed with the Tukey test. The value of DT imaging in the diagnosis and grading of cartilage damage was assessed with logistic regression analysis. Results: Samples had OARSI grades of 0 (n = 14), 1 (n = 11), 2 (n = 12), 3 (n = 4), and 4 (n = 2). Samples with an OARSI grade greater than 0 had significantly increased lambda(l), lambda(t), and MD (7%-25% increase) in the superficial cartilage growing deeper into cartilage with increasing OARSI grade. Samples with an OARSI grade greater than 0 showed significantly decreased FA in the deep cartilage (-25% to -35% decrease), suggesting that changes in the collagen architecture may occur early in cartilage degradation. DTI showed excellent performance in the detection of cartilage damage (accuracy, 0.95; 41 of 43 samples) and good performance in the grading of cartilage damage (accuracy, 0.74; 32 of 43 samples). Conclusion: DT imaging of articular cartilage can enable physicians to detect and grade early cartilage damage. (c) RSNA, 2012.
PMID: 23238155
ISSN: 0033-8419
CID: 249002

3D-imaging of the knee with an optimized 3D-FSE-sequence and a 15-channel knee-coil

Notohamiprodjo, Mike; Horng, Annie; Kuschel, Bernhard; Paul, Dominik; Li, Guobin; Raya, Jose G; Reiser, Maximilian F; Glaser, Christian
OBJECTIVES: To evaluate the clinical usefulness of an optimized 3D-Fast-Spin-Echo-sequence (3D-SPACE) in combination with a 15-channel knee-coil for 3D-imaging of the knee at 3T. METHODS: 15 volunteers and 50 consecutive patients were examined at 3T with fat-saturated moderately T2-weighted 3D-SPACE (Voxel-size (VS): 0.6mmx0.5mmx0.5mm/acquisition-time (AT) 10:44min) using a 15-channel knee-coil. Flip angle optimization and radial k-space reordering were applied. Signal- and contrast-to-noise-ratios (SNR, CNR) were compared to non-optimized 3D-SPACE (8-channel knee-coil) and conventional 2D-FSE (VS: 0.4mmx0.4mmx3mm/total AT: 12min). Two radiologists independently rated depiction of internal knee structures and assessed detection and depiction of cartilage and meniscus abnormalities compared to conventional 2D-FSE-sequences. Sensitivity and specificity were calculated for a subgroup with arthroscopy as reference standard. Statistical analysis was performed with paired t-tests, confidence intervals and weighted-kappa-coefficients. RESULTS: SNR and CNR particularly of fluid/cartilage of optimized 3D-SPACE were significantly higher (p<0.05) than of the non-optimized 3D-sequence and conventional 2D-sequence. Blurring and image inhomogeneity were reduced in the optimized sequence. The thin slice-thickness was beneficial for depiction of problematical anatomical structures such as meniscal roots. 3D-SPACE showed significantly higher diagnostic confidence (p<0.05) for diagnosis of cartilage lesions of the femoral trochlea. Overall sensitivity and specificity of 3D-SPACE and 2D-FSE for cartilage lesions was 82.3%/80.2% and 79.4%/84.2% and 100%/86.4% and 92.3%/81.8% for meniscus lesions. CONCLUSIONS: Optimized 3D-SPACE provides significantly higher signal and contrast compared to conventional 2D-FSE, particularly for fluid and cartilage, leading to improved diagnostic confidence, particularly in problematic areas, such as the femoral trochlea.
PMID: 22579529
ISSN: 0720-048x
CID: 179076

A new method to analyze dGEMRIC measurements in femoroacetabular impingement: preliminary validation against arthroscopic findings

Lattanzi, R; Petchprapa, C; Glaser, C; Dunham, K; Mikheev, A V; Krigel, A; Mamisch, T C; Kim, Y-J; Rusinek, H; Recht, M
OBJECTIVE: To validate a new method to analyze delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC) measurements in the hip for early assessment of cartilage defects in femoroacetabular impingement (FAI). METHODS: We performed a retrospective review of 10 hips in 10 FAI patients, who underwent hip arthroscopy. T(1)-weighted images and dGEMRIC T(1) maps were acquired at 1.5 T on coronal planes, including the anterior-superior, superior, posterior-superior hip cartilage. For all slices, a region of interest (ROI) was defined over the central portion of the femoral cartilage, assumed to be healthy, and T(1) values (x) were transformed to standard scores (z) using z = (x -mu)/sigma, where mu and sigma are the average and standard deviation of T(1) in the femoral ROI. Diagnostic performance of the resulting standardized dGEMRIC maps was evaluated against intraoperative findings and compared with that of a previously proposed dGEMRIC analysis as well as morphologic assessment. RESULTS: Assuming z = -2 or z = -3 as the threshold between normal and degenerated cartilage, sensitivity, specificity and accuracy were 88%, 51% and 62%, and 71%, 63% and 65%, respectively. By using T(1) = 500 ms as single threshold for all dGEMRIC T(1) maps, these values became 47%, 58% and 55%, whereas they were 47%, 79% and 70% for morphologic evaluation. CONCLUSIONS: Standardized dGEMRIC can increase the sensitivity in detecting abnormal cartilage in FAI and has the potential to improve the clinical interpretation of dGEMRIC measurements in FAI, by removing the effect of inter- and intra-patient T(1) variability.
PMID: 22771774
ISSN: 1063-4584
CID: 177023

Preliminary Study of 1.5-T MR Arthrography of the Shoulder With 3D Isotropic Intermediate-Weighted Turbo Spin Echo

Rybak, Leon D; La Rocca Vieira, Renata; Recht, Michael; Shepard, Timothy; Wiggins, Graham; Babb, James; Glaser, Christian
OBJECTIVE: The purpose of this study was to assess the performance of a near-isotropic 3D turbo spin-echo sequence in comparison with a standard 2D protocol and with arthroscopy in direct 1.5-T MR arthrography of the shoulder. SUBJECTS AND METHODS: Dilute gadolinium was injected into three cadaver shoulders, and 3D turbo spin-echo and 2D sequences were evaluated with respect to the signal-to-noise and contrast-to-noise ratios of key tissues. In a prospective study, the 3D intermediate-weighted fat-suppressed sequence (reformatted in three planes) was added to shoulder MR arthrography of 43 consecutively registered patients, 13 of whom later underwent arthroscopy. Two radiologists independently graded the 3D and 2D images in separate sessions to visualize normal anatomic features and to detect pathologic changes in the labrum, cartilage, cuff, and glenohumeral ligaments, assigning confidence levels to their readings. One reader repeated the readings of images of 10 patients. Reports of subsequent arthroscopy were available for 13 patients. RESULTS: The sequences performed comparably with respect to signal-to-noise and contrast-to-noise ratios in the cadavers. The 3D images suffered from mildly increased blurring, but the readers were significantly more confident in assessing the proximal biceps tendon and curved portions of the labrum and in their findings of partial tears of the articular side of the supraspinatus tendon and posterior labral tears on the 3D images. A larger number of partial-thickness cartilage defects were found on 2D images. CONCLUSION: The 3D turbo spin-echo sequence is a promising technique that can be used in shoulder arthrography with image quality and results comparable to those of traditional 2D techniques. Use of the 3D technique may result in greater anatomic detail in evaluating small obliquely oriented structures, including the curved portions of the labrum and the intraarticular portion of the biceps tendon.
PMID: 22733918
ISSN: 0361-803x
CID: 170437

Dynamic 3D-MR-angiography for assessing rheumatoid disease of the hand-A feasibility study

Notohamiprodjo M; Glaser C; Horng A; Helck A; Bauner KU; Reiser MF; Hatz HJ; Weckbach S
PURPOSE: To investigate highly temporally resolved MR-angiography (MRA) with time-resolved imaging with stochastic trajectories (TWIST) of the hand as supplementary tool for dynamic assessment of synovitis and vascular pathologies in rheumatoid diseases. MATERIAL AND METHODS: A coronal dynamic TWIST-MRA-sequence (0.7mmx0.7mmx1.4mm, temporal resolution 2.5s, time of acquisition 4min) of the predominantly affected hand of 17 patients with suspected rheumatoid disease was acquired after contrast administration (Multihance, Bracco Imaging SpA) at 3T (Magnetom VERIO, 8-channel-knee-coil, Siemens Healthcare). As standard of reference, contrast enhanced non fat-saturated coronal and fat-saturated axial T1-w sequences were acquired. These static sequences and the dynamic TWIST-MRA-maximum-intensity-projections (MIP) were separately assessed by two readers in consensus, recording the number of synovial lesions (wrist, intercarpal, metacarpophaleangal/proximal/distal interphalangeal joints), signs of tenosynovitis and vasculitis. Diagnostic confidence was rated (4-point-scale: 4=excellent; 1=non-diagnostic). Statistical significance was tested using the Wilcoxon-rank-sum-test. RESULTS: An insignificantly lower number of synovial lesions (n=72 vs. 89; p=0.1) and only 3/9 cases with tenosynovitis were identified by the TWIST-MRA. For detected lesions, diagnostic confidence was comparable (MRA: 3.64; static T1-w post contrast: 3.47). In patients with high clinical activity dynamic MRA showed very early synovial enhancement. Only dynamic MRA detected 3 cases of vasculitis (subsequently confirmed with digital-subtraction-angiography). CONCLUSION: TWIST-MRA facilitates fast detection of synovitis. Although dynamic MRA of the hand is inferior to static contrast enhanced sequences in assessing the number of synovitic and tenosynovitic lesions, its high temporal resolution allows for fast visual grading of disease activity and assessment of vasculitis without additional contrast material application
PMID: 21310563
ISSN: 1872-7727
CID: 128594