Purpose:To longitudinally evaluate cartilage matrix changes by using magnetic resonance (MR) imaging T1 r (T1 relaxation time in rotating frame) and T2 quantifi cation and to study the relationship between meniscal damage and cartilage degeneration in anterior cruciate ligament (ACL)-reconstructed knees. Materials and Methods:This was an institutional review board-approved, HIPAAcompliant study. Informed consent was obtained. Twelve patients with acute ACL injuries were imaged with 3.0-T MR imaging at baseline (after injury and prior to ACL reconstruction) and 1 year after ACL reconstruction. Ten age-matched healthy subjects were studied as controls. Cartilage T1 r and T2 were quantifi ed in full thickness, superfi cial, and deep layers of defi ned subcompartments at baseline and follow-up in ACL-injured knees and were compared with measures acquired in matched regions of control knees. Meniscal lesions were graded by using modifi ed subscores of the Whole-Organ Magnetic Resonance Imaging Score system. Results:T1 r values of the posterolateral tibial cartilage in ACLinjured knees were signifi cantly elevated at baseline compared with T1 r values of control knees and were not fully recovered at 1-year follow-up. T1 r values of weight-bearing medial femorotibial cartilage in ACL-injured knees were signifi cantly elevated at 1-year follow-up compared with those of control knees. No signifi cant differences in T2 values between ACL-injured and control knees were found. Patients with lesions in the posterior horn of the medial meniscus showed a greater increase of T1 r and T2 from baseline to follow-up in adjacent cartilage than patients without lesions in the medial meniscus. Conclusion:Quantitative MR imaging T1 r and T2 enable detection of changes in the cartilage matrix of ACL-reconstructed knees as early as 1 year after ACL reconstruction.q RSNA, 2010

Purpose To compare vertebral bone marrow fat content quantified with proton MR spectroscopy (1H-MRS) with the volume of abdominal adipose tissue, lumbar spine volumetric bone mineral density (vBMD), and blood biomarkers in postmenopausal women with and without type 2 diabetes mellitus (T2DM). Materials and Methods Thirteen postmenopausal women with T2DM and 13 age- and BMI-matched healthy controls were included in this study. All subjects underwent 1H-MRS of L1–L3 to quantify vertebral bone marrow fat content (FC) and unsaturated lipid fraction (ULF). QCT was performed to assess vBMD of L1–L3. The volumes of abdominal subcutaneous/visceral/total adipose tissue were determined from the QCT images and adjusted for abdominal body volume (SATadj/VATadj/TATadj). Fasting blood tests included plasma glucose and HbA1c. Results Mean FC showed an inverse correlation with vBMD (r=−0.452; p<0.05) in the whole study population. While mean FC was similar in the diabetic women and healthy controls (69.3 ± 7.5% vs. 67.5 ± 6.1%; p>0.05), mean ULF was significantly lower in the diabetic group (6.7 ± 1.0% vs. 7.9 ± 1.6%; p<0.05). SATadj and TATadj correlated significantly with mean FC in the whole study population (r=0.538 and r=0.466; p<0.05). In contrast to the control group, significant correlations of mean FC with VATadj and HbA1c were observed in the diabetic group (r=0.642 and r=0.825; p<0.05). Conclusion This study demonstrated that vertebral bone marrow fat content correlates significantly with SATadj, TATadj, and lumbar spine vBMD in postmenopausal women with and without T2DM, but with VATadj and HbA1c only in women with T2DM.

Purpose To determine the reproducibility of proton MR spectroscopy (1H-MRS) for assessing vertebral bone marrow adiposity at 3 Tesla (T); to evaluate variation of marrow adiposity at different vertebral levels; and to demonstrate the feasibility of using 1H-MRS at 3 T for evaluating marrow adiposity in subjects with low bone density. Materials and Methods Single voxel MRS was acquired at vertebral body L1 to L4 at 3 T in 51 post-menopausal females including healthy controls (n = 13) and patients with osteoporosis/osteopenia (n = 38). Marrow fat contents were compared between vertebral levels and between groups using analysis of variance (ANOVA). Six subjects were scanned twice to evaluate technique reproducibility. Results The average coefficient of variation of vertebral marrow fat content quantification was 1.7%. Marrow fat content significantly increased from L1 to L4. The average fat content was significantly elevated in patients with osteoporosis/osteopenia and in patients with diabetes compared to controls, adjusted for age and body mass index (BMI) (P < 0.05). Conclusions In vivo MRS at high field strength provides reliable measurement of marrow adiposity with excellent reproducibility and can be a valuable tool for providing complementary information on bone quality and potentially also fracture risk.

Purpose To quantitate bone marrow edema-like lesions (BMEL) and the radiologic properties of cartilage in knees with acute anterior cruciate ligament (ACL) injuries using T1ρ MRI over a 1 year time period. Methods 9 patients with ACL injuries were studied. MRI were acquired within 8 weeks of the injury, after which ACL reconstruction surgery was performed. Images were then acquired 0.5, 6, and 12 months following reconstructions. The volume and signal intensity of BMEL were quantified at baseline and follow up exams. T1ρ values were quantified in cartilage overlying the BMEL (OC) and compared to surrounding cartilage (SC) at all time-points. Results BMEL were most commonly found in the lateral tibia and lateral femoral condyle. Nearly 50% of BMEL resolved over 1-year. The T1ρ values of the OC in the lateral tibia, medial tibia, and medial femoral condyle were elevated compared to respective regions in SC at all time points, significant only in the lateral tibia (P < 0.05). The opposite results were found in the lateral femoral condyle. For the medial tibia and medial femoral condyle, none of the time periods were significantly different. The percent increase in T1ρ values of OC in the lateral tibia was significantly correlated to BMEL-volume (r = 0.74, P < 0.05). At 1-year, the OC in the lateral tibia, medial tibia, and medial femoral condyle showed increased T1ρ values despite improvement of BMEL. Conclusions In patients following ACL tear and reconstruction, (1) the cartilage overlying BMEL in the lateral tibia experiences persistent T1ρ signal change immediately after acute injuries and at 1-year follow up despite BMEL improvement. (2) The superficial layers of the overlying cartilage demonstrate greater matrix damage than the deep layers, and (3) the volume of the BMEL may predict the severity of the overlying matrix's damage in the lateral tibia. T1ρ is capable of quantitatively and noninvasively monitoring this damage and detecting early cartilage changes in the lateral tibia over time. Level of Evidence IV

Purpose:To determine the frequency of degenerative knee morphologic abnormalities in asymptomatic individuals by using 3-T magnetic resonance (MR) imaging and to investigate the characteristics and evolution of cartilage T2 values in relation to morphologic abnormalities with a longitudinal study. Materials and Methods:The study was approved by the institutional review board and was compliant with HIPAA. Ninety-fi ve asymptomatic subjects aged 45-78 years who were free of risk factors for osteoarthritis (OA) were selected from the Osteoarthritis Initiative normal control cohort and examined with radiography and 3-T MR imaging. Data obtained at both baseline and 2-year follow-up were analyzed. OA-related knee abnormalities were analyzed by using the wholeorgan MR imaging score (WORMS). Cartilage T2 maps were generated by using sagittal two-dimensional multiecho spin-echo images of the right knee. Statistical significance was determined with the Student t test, the paired t test, a mixed random effects model, one-way analysis of variance, and a multiple linear regression model. Results:Knee abnormalities were identifi ed with a high frequency (90% at baseline and 92 % at 2-year follow-up). The prevalence of hyaline cartilage lesions was particularly high (86% at baseline and 84% at follow-up). A signifi cant longitudinal increase in T2 was detected in the tibiofemoral cartilage but not the patellofemoral cartilage ( P = .0072). The longitudinal change in T2 was signifi cantly associated with worsening of the cartilage WORMS ( P = .038). Conclusion:Asymptomatic subjects have a high frequency of OA-related morphologic abnormalities. A signifi cant increase in tibiofemoral cartilage T2 was detected over the 2-year period. A greater increase in T2 was associated with increased progression of cartilage morphologic abnormalities.q RSNA, 2011

Effective quality improvement (QI) education should improve patient care, but many curriculum studies do not include clinical measures. The research team evaluated the prevalence of QI curricula with clinical measures and their association with several curricular features. MEDLINE, Embase, CINAHL, and ERIC were searched through December 31, 2013. Study selection and data extraction were completed by pairs of reviewers. Of 99 included studies, 11% were randomized, and 53% evaluated clinically relevant measures; 85% were from the United States. The team found that 49% targeted 2 or more health professions, 80% required a QI project, and 65% included coaching. Studies involving interprofessional learners (odds ratio [OR] = 6.55; 95% confidence interval [CI] = 2.71-15.82), QI projects (OR = 13.60; 95% CI = 2.92-63.29), or coaching (OR = 4.38; 95% CI = 1.79-10.74) were more likely to report clinical measures. A little more than half of the published QI curricula studies included clinical measures; they were more likely to include interprofessional learners, QI projects, and coaching.

In this technique development study, high-resolution peripheral quantitative computed tomography (HR-pQCT) was applied to non-invasively image and quantify 3D joint space morphology of the wrist and metacarpophalangeal (MCP) joints of patients with rheumatoid arthritis (RA). HR-pQCT imaging (82μm voxel-size) of the dominant hand was performed in patients with diagnosed rheumatoid arthritis (RA, N=16, age:52.6±12.8) and healthy controls (CTRL, N=7, age:50.1±15.0). An automated computer algorithm was developed to segment wrist and MCP joint spaces. The 3D distance transformation method was applied to spatially map joint space width, and summarized by the mean joint space width (JSW), minimal and maximal JSW (JSW.MIN, JSW.MAX), asymmetry (JSW.AS), and distribution (JSW.SD) – a measure of joint space heterogeneity. In vivo precision was determined for each measure by calculating the smallest detectable difference (SDD) and root mean square coefficient of variation (RMSCV%) of repeat scans. Qualitatively, HR-pQCT images and pseudo-color JSW maps showed global joint space narrowing, as well as regional and focal abnormalities in RA patients. In patients with radiographic JSN at an MCP, JSW.SD was two-fold greater versus CTRL (p<0.01), and JSW.MIN was more than two-fold lower (p<0.001). Similarly, JSW.SD was significantly greater in the wrist of RA patients versus CTRL (p<0.05). In vivo precision was highest for JSW (SDD: 100μm, RMSCV: 2.1%) while the SDD for JSW.MIN and JSW.SD were 370 and 110μm, respectively. This study suggests that in vivo quantification of 3D joint space morphology from HR-pQCT, could improve early detection of joint damage in rheumatological diseases.

Objective Our objective is to understand the biological and mechanical pathways linking cartilage, bone, and marrow changes in the progression of osteoarthritis (OA). The aim of the present study was to evaluate bone structure and composition within bone marrow edema-like lesion (BMEL) regions associated with knee OA. Methods Tibial plateau specimens (n = 18) were collected from 10 subjects with knee OA scheduled for total knee arthroplasty (TKA). Magnetic resonance (MR) imaging was used to identify BMEL and quantify metrics of cartilage composition. Micro-computed tomography (μCT) and high-resolution peripheral quantitative computed tomography (HR-pQCT) were used to quantify density and microstructure of the subchondral trabecular bone. Fourier transform infrared (FTIR) spectroscopy was used to quantify tissue composition. Results Trabecular bone within BMEL was higher in volume fraction, with more and thicker trabeculae that were more plate-like in structure compared to unaffected regions. BMEL trabecular tissue composition had decreased phosphate and carbonate content. Marrow infiltration by a fibrous collagen network and evidence of increased bone remodeling were present. Structural and compositional changes were specifically localized to regions underlying cartilage degradation. Conclusion These results support the paradigm of focal interactions among bone, marrow, and cartilage in the progression of knee OA. Quantitative evaluation of tissue changes and interactions may aid in the understanding of disease pathophysiology and provide imaging markers for disease progression.