5/10/2013 Disclosures • No financial disclosures Quantitative Evaluation of Fatty Infiltration of the Rotator Cuff Muscles with IDEAL Magnetic Resonance Imaging Drew Lansdown, MD Lorenzo Nardo, MD Dmitrios Karampinos, PhD Julio Carballido-Gamio, PhD Thomas Link, MD Benjamin Ma, MD Roland Krug, PhD Fatty Infiltration and Muscle Atrophy Background • Muscles of the rotator cuff undergo degenerative • Rotator cuff tears account changes after tendon injury 1 for 4.5 million physician visits each year 1 – Fatty infiltration • 75,000 rotator cuff repairs – Muscle atrophy annually 1 • Pathophysiology not fully understood 1 • May result in painful – Decreased loading of muscle due to tendon injury shoulder with limited function – Traction injury to suprascapular nerve • 54% of asymptomatic – Neoangiogenesis and metabolic changes patients over age 60 have • Both are independent predictors of outcome after partial or full-thickness surgical repair 2 tear 2 1. Oh, et al. CORR, 2007. 1. Chaudhury, et al. Arthritis Care & Research, 2012. 2. Reilly, et al. Ann R Coll Surg Eng , 2006 2. Gladstone, et al. AJSM , 2007. 1
5/10/2013 Goutallier Classification Clinical Relevance of Fatty Infiltration • First described for CT and modified for MRI 1,2 • Cuff integrity after repair is directly related to • Qualitative assessment muscle quality 1,2 – Re-tear rate is 50-70% with FI >= grade 2 • Moderate inter-observer reliability (Κ = 0.53) 3 • Unclear if these changes are reversible Grade 3 Grade 4 Grade 0 Grade 1 Grade 2 Equal muscle More fat Normal Streaks of fat More muscle – Goutallier - Possibly reverses in SS but not in IS and fat than muscle than fat – Gladstone – Minimal to no progression with successful repair 1. Goutallier, et al. CORR , 1994. 1. Goutallier, et al. CORR , 1994. 2. Fuchs, et al. JSES , 1999. 2. Gladtsone, et al. AJSM , 2007. 3. Lippe, et al. Arthroscopy . 2012. IDEAL MRI Hypothesis • Iterative decomposition of • IDEAL MRI fat fraction mapping provides a water and fat with echo continuous variable that is closely correlated asymmetry and least- with the Goutallier classification squares estimation (IDEAL) • Generates accurate • Fat fraction values are correlated with quantitative fat-fraction strength testing from physical examination map • Previous animal studies validated fat content assessment with histologic studies 1 1. Hines, et al. Radiology, 2010. 2
5/10/2013 Study Design Image Segmentation • 57 patients undergoing • Segmented on sagittal- Relevant Imaging Acquisition routine shoulder MRI Purpose oblique intermediate- Sequence Parameters • IDEAL sequence added weighted FSE images to clinical study • Scapular “Y” identified TR=2513 ms • Goutallier grade given Goutallier Sagittal TE = 31 ms, classification PDW-FSE and a total of 4 slices rBW = 62.5 kHz, for each rotator cuff ETL = 10, NEX = 4 muscle for each patient were segmented • Range of motion and • Fat-fraction values were 6-points, TE=2.1 ms pain levels (VAS) Sagittal calculated from the ∆ TE=1.0 ms IDEAL- FA=3 ° recorded from Fat TR=10.8 ms, SPGR segmented regions quantification retrospective review of using IDEAL fat fraction rBW = 62.5 kHz, outpatient notes NEX=1 maps Fat Fraction Values Correlate to IDEAL Values Have Good Goutallier Classification Intra/Inter-User Reliability Teres All Supra Infra Subscap Minor muscles Goutallier Mean Fat Range Grade Fraction Value Intra- reproducibility 0.96 0.84 0.92 0.96 0.92 0 2.1% (1.3%) 0 – 5.59% Reader #1 1 5.6% (2.3%) 1.1-9.70% Intra- reproducibility 0.85 0.87 0.82 0.96 0.90 2 8.5% (2.7%) 6.4 – 14.86% Reader #2 3 16.2% (1.1%) 15.25 – 17.77% Inter- 4 24.7% (3.4%) 19.85 – 29.63% 0.81 0.84 0.81 0.91 0.84 reproducibility Pearson’s correlation coefficient r = 0.93 3
5/10/2013 IDEAL Values Correlate with Clinical Conclusions Parameters • Fat fraction values are reproducible (κ = 0.81 – Spearman Spearman Rank Spearman Rank Spearman Muscles p-values 0.96)and allow for a continuous variable for Correlation-IDEAL Correlation-GC p-values GC IDEAL fat quantification Supraspinatus • Strength testing in supraspinatus, Pain – VAS 0.128 0.012 0.3557 0.9318 FF Strength 0.206 0.032 0.1382 0.8215 infraspinatus and subscapularis are Ab Strength 0.448 0.223 0.1201 0.0011* significantly correlated to IDEAL values Infraspinatus Pain – VAS 0.119 0.087 0.3910 0.5336 • IDEAL MRI can lead to improved evaluation ER Strength 0.368 0.370 0.0067* 0.0064* and understanding of fatty infiltration Subscapularis Pain – VAS 0.313 0.193 0.1625 0.0214* IR Strength 0.39 0.30 0.0051* 0.0357* Acknowledgements • Benjamin Ma, MD • Roland Krug, PhD • Lorenzo Nardo, MD • Dmitrios Karampinos, PhD • Julio Carballido-Gamio, PhD • Thomas Link, MD 4
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