Fat-suppressed Magnetic Resonance Imaging Research Articles

Association of physical activity and physical performance with tibial cartilage volume and bone area in young adults.

IntroductionPhysical activity has been recommended to patients with knee osteoarthritis for improving their symptoms. However, it is still controversial if physical activity has effects on joint structures including cartilage volume. The aim of this study was to describe the associations between physical activity and performance measured 5 years prior and tibial cartilage volume and bone area in young adults.MethodsSubjects broadly representative of the Australian population (n = 328, aged 31–41 years, female 47.3 %) were selected from the Childhood Determinants of Adult Health study. They underwent T1-weighted fat-suppressed magnetic resonance imaging (MRI) scans of their knees. Tibial bone area and cartilage volume were measured from MRI. Physical activity (measured using long international physical activity questionnaire (IPAQ)) and performance measures (long jump, leg muscle strength, physical work capacity (PWC170)) were measured 5 years prior.ResultsIn multivariable analyses, total physical activity (min/week) (β: 0.30 mm3, 95 % CI: 0.13,0.47), vigorous (β: 0.54 mm3, 95 % CI: 0.13,0.94), moderate (β: 0.34 mm3, 95 % CI: 0.01,0.67), walking (β: 0.40 mm3, 95 % CI: 0.07,0.72) and IPAQ category (β: 182.9 mm3, 95 % CI: 51.8,314.0) were positively associated with total tibial cartilage volume but not tibial bone area. PWC170, long jump and leg muscle strength were positively and significantly associated with both total tibial cartilage volume and total tibial bone area; and the associations with tibial cartilage volume decreased in magnitude but remained significant for PWC170 and long jump after further adjustment for tibial bone area.ConclusionWhile tibial bone area is affected only by physical performance, total tibial cartilage volume can be influenced by both physical activity and performance in younger adults. The clinical significance suggests a beneficial effect for cartilage but the bone area association was restricted to performance suggesting other factors rather than physical activity may be important.

Bone marrow lesions can be subtyped into groups with different clinical outcomes using two magnetic resonance imaging (MRI) sequences

IntroductionBone marrow lesions (BMLs) are features detected on MRI that are important in the pathogenesis of knee osteoarthritis. Since BMLs reflect heterogeneous pathologies this prospective cohort study examined whether BMLs detected using different MRI sequences are associated with distinct structural and clinical endpoints.MethodsA total of 297 community-based adults without knee pain were examined to identify BMLs visualised using three-dimensional T1-weighted gradient-echo fat-suppressed (T1-weighted sequences) fat-suppressed and fat-saturated FSE T2-weighted MRI sequences (T2-weighted sequences) at baseline. Cartilage volume was measured at baseline and follow-up, while incident knee pain was assessed at follow-up, an average of 2.3 years later.ResultsAt baseline, 46 BMLs were visualised in 39 participants. Of the 45 BMLs visualised on T2-weighted sequences, 34 (74 %) were also seen on T1-weighted sequences. One BML was seen on only T1-weighted sequences. Knees with BMLs visualised on both T1- and T2-weighted sequences had significantly higher medial tibial cartilage volume loss (45 mm3/annum, standard error of the mean (SEM) 14) than those with BMLs identified on only T2-weighted sequences (−13 mm3/annum SEM 19), after adjustment for age, gender and body mass index (p = 0.01). Incident knee pain was more likely in individuals with BMLs in the medial compartment visualised on both T1- and T2-weighted (eight participants, 53 %) compared to those with BMLs on only T2-weighted sequences (0 %) or no BMLs (76 participants, 31 %, p = 0.02).ConclusionsBMLs present on both T1- and T2-weighted MRI sequences were associated with increased medial tibial cartilage loss and incident knee pain compared with those BMLs seen only on T2-weighted sequences. This suggests that combining different MRI sequences may provide more informative targets in the prevention and treatment of knee osteoarthritis.

Childhood Physical Performance Measures and Adulthood Knee Cartilage Volume and Bone Area: A 25-Year Cohort Study.

We aimed to determine the associations between childhood physical performance measures and tibial cartilage volume and tibial bone area in adults 25 years later. Participants (n = 330, ages 31-41 years, female 47%) were selected from the Australian Schools Health and Fitness Survey of 1985. The participants underwent T1-weighted fat-suppressed magnetic resonance imaging (MRI) of their knees. Tibial bone area and cartilage volume were measured from MRI. Childhood measures, including physical work capacity at 170 beats per minute (PWC170 ), leg strength, number of sit-ups, long-run, and short-run were measured in 1985. PWC170 and leg strength measures were repeated after 20 years in their adulthood. Linear regression analysis was used to determine the association of performance measures with cartilage volume. There were consistent positive associations of all childhood measures, including PWC170 (β = 0.38 cm(2) per 10 watts, 95% confidence interval [95% CI] 0.15, 0.60), leg strength, long-run, short-run, and sit-ups with adult medial and total tibial bone area. Similarly, there was an association of PWC170 and sit-ups with adult medial tibial cartilage volume. After further adjustment for tibial bone area, the association between PWC170 and medial and total (β = 0.08 cm(3) per 10 watts, 95% CI 0.02, 0.10) tibial cartilage volume decreased in magnitude but remained significant. Childhood physical performance measures, especially PWC170 , were associated with knee tibial bone area and cartilage volume in adulthood. The associations with cartilage volume appeared to be partially mediated by bone area. This suggests physical performance measures in childhood can independently influence adult knee structures.

Cartilage T1ρ and T2 Relaxation Times in Patients With Mild-to-Moderate Radiographic Hip Osteoarthritis.

To analyze region-specific T1ρ and T2 relaxation times of the hip joint cartilage in relation to presence or absence of radiographic hip osteoarthritis (OA) and presence or absence of magnetic resonance imaging (MRI)-detected cartilage defects. Weight-bearing radiographs and 3T MRI studies of the hip were obtained from 84 volunteers. Based on Kellgren/Lawrence (K/L) scoring of the radiographs, 54 subjects were classified as healthy controls (K/L grade ≤1) and 30 were classified as having mild or moderate radiographic hip OA (K/L grades 2 or 3, respectively). Two-dimensional fat-suppressed fast spin-echo MRI sequences were used for semiquantitative clinical scoring of cartilage defects, and a T1ρ/T2 sequence was used to quantitatively assess the cartilage matrix. The femoral and acetabular cartilage was then segmented into 8 regions and the mean T1ρ/T2 values were calculated. Differences in T1ρ and T2 relaxation times were compared between subjects with and those without radiographic hip OA, and those with and those without femoral or acetabular cartilage defects. Higher T1ρ and T2 relaxation times in the anterior superior and central regions of the acetabular cartilage were seen in individuals with radiographic hip OA and those with acetabular cartilage defects compared to their respective controls (P < 0.05). In the femoral cartilage, the differences in T1ρ and T2 were not significant for any of the comparisons. Significant differences in the T1ρ and T2 values (each P < 0.05) were found in more subregions of the cartilage and across the whole cartilage when subjects were stratified based on the presence of MRI-detected cartilage defects than when they were stratified based on the presence of radiographic hip OA. T1ρ and T2 relaxation parameters are sensitive to the presence of cartilage degeneration. Both parameters may therefore support MRI evidence of cartilage defects of the hip.

Changes in patellofemoral bone marrow lesions and knee pain: Natural history and the associations with structure

s / Osteoarthritis and Cartilage 23 (2015) A82eA416 A298 2. IGF-II is capable of promoting cartilage matrix maintenance in injuryinduced OA in mice and in human OA cartilage ex vivo cultures. 469 CHANGES IN PATELLOFEMORAL BONE MARROW LESIONS AND KNEE PAIN: NATURAL HISTORY AND THE ASSOCIATIONS WITH STRUCTURE Z. Zhu y, C. Ding y, X. Jin y, B. Antony y, W. Han y, L. Laslett y, F. Cicuttini z, G. Jones y. yMenzies Inst. for Med. Res., Hobart, Australia; zDept. of Epidemiology and Preventive Med., Monash Univ., Melbourne, Melbourne, Australia Purpose: Bone marrow lesions (BMls) are recognized as an important subchondral feature in knee OA and play a vital role in the diease progression. The patellofemoral joint (PFJ) is a common site of pain and contributes to functional limitations among OA patients. However, there are very few clinical or epidemiological studies that reveal the association between PFJ BMLs and clinical symptoms as well as cartilage structural morphologies. Meanwhile, the natural history of PFJ BMLs has not yet been described. The aims of this study were, therefore, to describe the natural history of MRI-detected BMLs in PFJ over 2.6 years and evaluate the association between increases in PFJ BMLs, knee pain and knee cartilage morphology in older adults. Methods: 406 males and females were randomly selected from local community (mean age 63 years, range 51 to 79) and followed up for 2.6 years. PFJ BMLs were determined on T2-weighted fat saturated magnetic resonance imaging (MRI) using Whole-Organ MRI Score system (WORMS). Knee cartilage volume and cartilage defects scores (0-4) were determined on T1-weighted fat suppression MRI using WORMS. Knee pain was accessed byWestern Ontario and McMaster Universities Osteoarthritis (WOMAC) scores. Student's t-tests and Pearson's c2 tests were used to compare the differences between subjects with and without an increase in PFJ BMLs. Crude and adjusted linear regression was used to determine whether PFJ BML changes over 2.5 years were associated with changes in knee pain in the different sub-scales over 5 years, before and after adjustment for potential confounders. Binary logistic regression was used to examine the associations between increases in PFJ BMLs as an outcome, and baseline cartilage volumes as well as baseline cartilage defect scores as predictors, both before and after adjustment for potential confounders. Results: At baseline, 27% (n1⁄4109) had PFJ BMLs, 24% of these showed progression (change in score of 1) at follow-up, 44% persisted and 21% completely resolved. Of those 73% (n1⁄4297) who did not have PFJ BMLs at baseline, 19.7% of them developed new PFJ BMLs over 2.6 years. In multivariable analysis, change in PFJ BMLs was positively associated with increases in total knee pain (b: 0.81, 95% CI: 0.15, 1.48) and knee pain when going up/down stairs (b: 0.29, 95% CI: 0.08, 0.50) over 5 years. While baseline patellar cartilage volume predicted a decrease in PFJ BMLs (OR: 0.62, 95% CI: 0.43, 0.90), baseline patellar cartilage defects were associated with an increase in PFJ BMLs (OR: 1.75, 95% CI: 1.28, 2.40) over 2.6 years. Tibiofemoral cartilage volume and defects were not associated with changes in PFJ BMLs. Conclusions: PFJ BMLs are not static and change is clinically relevant. An increase in PFJ BMLs can be predicted by reduced patellar cartilage volume and increased patellar cartilage defects site-specifically.

IGF-II inhibits promotes cartilage integrity in experimental osteoarthritis and IL-1β-induced catabolic activity in chondrocytes

IGF-II inhibits promotes cartilage integrity in experimental osteoarthritis and IL-1β-induced catabolic activity in chondrocytes

MRI characteristics of intraductal papilloma

Intraductal papilloma (IDP) is the most common pathological finding in women with pathological nipple discharge. Magnetic resonance imaging (MRI) has shown potential for characterizing breast tumors; however, MRI findings of IDPs are inconclusive, and certain diagnostic standards are lacking. To characterize the MRI features of IDP from a relatively large cohort. We retrospectively reviewed from 358 women with IDPs that were confirmed by histopathology. The clinical and imaging findings in 70 patients who underwent preoperative MRI were analyzed. MRI analyses included morphology and dynamic contrast-enhanced MRI. In 70 patients, 77 IDPs were detected on MRI, which revealed the following three patterns: small luminal mass papillomas; tumor-like papillomas; and MRI-occult papillomas. Fourteen IDPs involved small, oval, smooth, and contrast-enhanced masses at the posterior end of the enlarged duct corresponding to small luminal mass papillomas. Seven IDPs had large diameters along the direction of the breast duct, indicating the typical MRI findings for IDP. Of 47 tumor-like papillomas, 16 cases showed large diameters along the direction of the breast duct and close to the nipple (within 4 cm), seven cases resembled invasive breast cancer on MRI, and the remaining 24 were (24/47) undistinguishable from other benign breast diseases. Sixteen IDPs were MRI-occult papillomas that could not be distinguished from the surrounding benign disease by either contrast-enhanced MRI or fat-suppressed T2-weighted MRI. Small luminal mass papillomas or tumor-like papillomas with the largest diameters along the direction of the breast duct and close to the nipple (within 4 cm) might be the typical MRI findings for IDPs.

Chemical shift and fat suppression magnetic resonance imaging of thymus in myasthenia gravis.

Chemical shift and fat suppression magnetic resonance imaging of thymus in myasthenia gravis.

Feasibility of fat-saturated T2-weighted magnetic resonance imaging with slice encoding for metal artifact correction (SEMAC) at 3T

Background and PurposeFluid-sensitive MR imaging in postoperative evaluation is important, however, metallic artifacts is inevitable. The purpose is to investigate the feasibility of fat-saturated slice encoding for metal artifact correction (SEMAC)-corrected T2-weighted magnetic resonance (MR) at 3T in patients with spinal prostheses. MethodsFollowing institutional review board approval, 27 SEMAC-encoded spinal MRs between September 2012 and October 2013 in patients with spinal metallic prostheses were analyzed. The MR images were scanned on a 3T MR system including SEMAC-corrected and uncorrected fast spin echo (FSE) T2-weighted MR images with fat-saturation. Two musculoskeletal radiologists compared the image sets and qualitatively analyzed the images using a five-point scale in terms of artifact reduction around the prosthesis, visualization of the prosthesis and pedicle, and intervertebral neural foramina. Quantitative assessments were performed by calculating the ratio of signal intensity from the fixated vertebra and that from upper level vertebra. For statistical analyses, paired t-test was used. ResultsFat-saturated SEMAC-corrected T2-weighted MR images enabled significantly improved metallic artifact reduction (P<0.05). Quantitative evaluation of the signal intensity ratio of screw-fixated vertebra and upper level vertebra showed a significantly lower ratio on fat-saturated SEMAC images (P<0.05), however, the high signal intensity of signal pile-up could be not completely corrected. ConclusionSEMAC correction in fat-suppressed T2-weighted MR images can overcome the signal loss of metallic artifacts and provide improved delineation of the pedicle screw and peri-prosthetic region. Signal pile-up, however, could not be corrected completely, therefore readers should be cautious in the evaluation of marrow around the prosthesis.

Magnetic resonance imaging, computed tomography, and gross anatomy of the canine tarsus.

To describe the normal anatomy of the soft tissues of the canine tarsus as identified on computed tomography (CT) and magnetic resonance imaging (MRI) and to evaluate specific MRI sequences and planes for observing structures of diagnostic interest. Prospective descriptive study. Canine cadavers (n = 3). A frozen cadaver pelvic limb was used to trial multiple MRI sequences using a 1.5 T superconducting magnet and preferred sequences were selected. Radiographs of 6 canine cadaver pelvic limbs confirmed the tarsi were radiographically normal. A 16-slice CT scanner was used to obtain 1 mm contiguous slices through the tarsi. T1-weighted, proton density with fat suppression (PD FS) and T2-weighted MRI sequences were obtained in the sagittal plane, T1-weighted, and PD FS sequences in the dorsal plane and PD FS sequences in the transverse plane. The limbs were frozen for one month and sliced into 4-5 mm thick frozen sections. Anatomic sections were photographed and visually correlated to CT and MR images. Most soft tissue structures were easiest to identify on the transverse MRI sections with cross reference to either the sagittal or dorsal plane. Bony structures were easily identified on all CT, MR, and gross sections. The anatomy of the canine tarsus can be readily identified on MR imaging.

MR Arthrography: Impact of Steroids, Local Anesthetics, and Iodinated Contrast Material on Gadolinium Signal Intensity in Phantoms at 1.5 and 3.0 T

To determine if gadolinium signal intensity at direct magnetic resonance (MR) arthrography is affected by the addition of steroids, anesthetics, or iodinated contrast material. This study did not require approval by the institutional review board because no patients or patient data were involved. An in vitro study was performed to evaluate various concentrations of three gadolinium contrast agents (gadopentetate dimeglumine, gadobenate dimeglumine, and gadofosveset trisodium) diluted in either saline or iodinated contrast material (50% and full-strength iohexol 300). Three steroids (betamethasone, triamcinolone, and methylprednisolone) and three local anesthetics (lidocaine, ropivacaine, and bupivacaine) were added to solutions in clinical doses. T1-weighted fat-suppressed MR imaging sequences were performed in phantoms at 1.5 and 3.0 T. Signal intensities were measured. All experiments were repeated in full for a total of three replications each. The data were analyzed by using two-way factorial analysis of variance. Dilution of gadolinium into iohexol reduced the signal intensity in all samples compared with dilution in saline alone. Peak signal intensities were at 0.625 and 1.25 mmol/L of gadolinium in iohexol at both magnet strengths. At 1.5 T, the addition of steroids and anesthetics to the saline solutions had no impact on the signal intensity curves, with the peak signal intensity at gadolinium concentrations of 2.5 and 1.25 mmol/L. At 3.0 T, the addition of steroids and anesthetics had minimal effect on signal intensity curves, with the peak signal intensity at 1.25 mmol/L of gadolinium. The addition of steroids and/or anesthetics to gadolinium solutions for MR arthrography does not substantially impact signal intensity. When gadolinium is diluted into a 50% or greater strength of iohexol, the signal intensity curve shifts so that the maximum signal intensity is obtained with lower gadolinium concentrations (0.625-1.25 mmol/L).

Reliability of common clinical standing balance tests for people with hip osteoarthritis

Reliability of common clinical standing balance tests for people with hip osteoarthritis

Pediatric Distal Forearm and Wrist Injury: An Imaging Review

Injuries to the pediatric distal forearm and wrist have myriad manifestations. Growth plate injuries can occur in the skeletally immature child. An unfused growth plate is less robust than ligamentous complexes and therefore is more easily injured. The Salter-Harris fracture classification system is used to grade physeal injuries based on their imaging appearance. This grading has prognostic significance: higher grades imply an increased likelihood of eventual growth disturbance. A disrupted distal radioulnar joint characterizes Galeazzi-type injuries at all ages; however, before skeletal maturity is attained, a disrupted radioulnar joint can manifest as a distal ulnar physeal separation with associated epiphysiolysis of the distal ulna, termed a Galeazzi-equivalent fracture. Bone contusions can be diagnosed using fluid-sensitive fat-suppressed magnetic resonance imaging, and their detection can alter the prognosis. The unique cartilaginous cushion of the developing bony carpus imparts resilience to fracture and dislocation until carpal maturity is reached. Chronic compressive forces to the wrist in a skeletally immature gymnast can result in a distinct pattern of bone and soft-tissue injury referred to as gymnast wrist. If the distal radial physis fuses prematurely, ulnar growth will outpace radial growth, leading to positive ulnar variance and consequent chronic wrist pain from ulnar impaction.

Similarity of fibroglandular breast tissue content measured from magnetic resonance and mammographic images and by a mathematical algorithm.

Women with high breast density (BD) have a 4- to 6-fold greater risk for breast cancer than women with low BD. We found that BD can be easily computed from a mathematical algorithm using routine mammographic imaging data or by a curve-fitting algorithm using fat and nonfat suppression magnetic resonance imaging (MRI) data. These BD measures in a strictly defined group of premenopausal women providing both mammographic and breast MRI images were predicted as well by the same set of strong predictor variables as were measures from a published laborious histogram segmentation method and a full field digital mammographic unit in multivariate regression models. We also found that the number of completed pregnancies, C-reactive protein, aspartate aminotransferase, and progesterone were more strongly associated with amounts of glandular tissue than adipose tissue, while fat body mass, alanine aminotransferase, and insulin like growth factor-II appear to be more associated with the amount of breast adipose tissue. Our results show that methods of breast imaging and modalities for estimating the amount of glandular tissue have no effects on the strength of these predictors of BD. Thus, the more convenient mathematical algorithm and the safer MRI protocols may facilitate prospective measurements of BD.

Effect and Possible Mechanism of Muscle-Splitting Approach on Multifidus Muscle Injury and Atrophy After Posterior Lumbar Spine Surgery

Multifidus muscle injury and atrophy are common after posterior lumbar spine surgery and are associated with low back pain and functional disability. In theory, muscle-splitting and retraction with a self-retaining retractor are considered to be the major surgical factors. The effects and mechanisms of retraction have been well studied, but the exact effect and possible mechanism of injury and atrophy after muscle-splitting still lack experimental evidence. New Zealand White rabbits were divided into two groups. In group S, through a skin and lumbodorsal fascial incision, the bilateral multifidus muscles were dissected from the osseous structures in the standard fashion, while in group C, only a skin and lumbodorsal fascial incision was made. In each group, the multifidus muscle was evaluated by magnetic resonance imaging (MRI) and by histological analysis at three and forty-eight hours and at one, three, six, twelve, and twenty-four weeks after surgery. In group C, there was no injury or atrophy of the multifidus muscle after surgery. In group S, the mean T2-weighted signal intensity ratios of gross multifidus to psoas on fat-suppressed T2-weighted cross-sectional MRI scans peaked on week 3 and returned to baseline on week 24. Necrosis and inflammation of the multifidus muscle were evident and became more severe at one week. Fibrotic change was mainly seen at three and six weeks after surgery, and fatty degeneration mainly occurred at twelve and twenty-four weeks. Decreased acetylcholine activity and granular degeneration of the neuromuscular junction were observed at all follow-up times, and the numbers of degenerating neuromuscular junctions increased significantly with time after surgery. The splitting approach is an important cause of multifidus muscle injury and atrophy in posterior lumbar spine surgery. Denervation and disuse may be important factors in multifidus muscle atrophy in the splitting approach. This study provides a basis for the prevention of multifidus muscle injury and atrophy after posterior lumbar surgery.

Serratus plane block: a novel ultrasound-guided thoracic wall nerve block

We present a novel ultrasound-guided regional anaesthetic technique that may achieve complete paraesthesia of the hemithorax. This technique may be a viable alternative to current regional anaesthetic techniques such as thoracic paravertebral and central neuraxial blockade, which can be technically more challenging and have a higher potential side-effect profile. We performed the serratus block at two different levels in the midaxillary line on four female volunteers. We recorded the degree of paraesthesia obtained and performed fat-suppression magnetic resonance imaging and three-dimensional reconstructions of the spread of local anaesthetic in the serratus plane. All volunteers reported an effective block that provided long-lasting paraesthesia (750-840 min). There were no side-effects noted in this initial descriptive study. While these are preliminary findings, and must be confirmed in a clinical trial, they highlight the potential for the serratus plane block to provide analgesia following surgery on the thoracic wall. We suggest that this novel approach appears to be safe, effective, and easy to perform, and is associated with a low risk of side-effects.

Intraosseous leiomyosarcoma arising in the epiphysis of the distal femur

Herein, we present a rare case of intraosseous leiomyosarcoma arising in the epiphysis of the distal femur and showing unusual radiographic features. A 44-year-old man presented with a pain in the left knee joint. Computed tomography revealed an intraosseous lesion with slightly increased attenuation and a thin marginal sclerotic rim in the femoral medial condyle. The signal of the lesion was hypointense on T1-weighted magnetic resonance (MR) images and hyperintense on fat-suppressed T2-weighted MR images. After gadolinium administration, the signal of the lesion was moderately and diffusely enhanced. The histological diagnosis of leiomyosarcoma was made based on a preoperative core biopsy specimen. Microscopic examination of the resected specimen revealed an ill-defined intraosseous tumor composed of proliferated atypical and mildly pleomorphic smooth muscle cells permeating among the bone trabeculae with only focal destruction of the bone trabeculae and low mitotic activity, indicating low grade leiomyosarcoma. The bone trabeculae at the periphery of the tumor were mildly thickened and anastomosed with a rim of an increased number of osteoblasts. Systemic examination showed no tumorous lesions in other anatomical sites. Leiomyosarcomas rarely present in the bone as a diffuse intertrabecular growth, even in low grade tumors.

Expanding Applications of the Subchondroplasty Procedure for the Treatment of Bone Marrow Lesions Observed on Magnetic Resonance Imaging

Increase in signal on T2-weighted fat-suppressed magnetic resonance imaging is referred to as a bone marrow lesion (BML). Although there is overlap with avascular necrosis, a subset of BMLs is unique and typically associated with overlying chondrosis in a high-load region of the joint. These lesions are often associated with localized knee pain. Several current studies demonstrate improvement in patient-reported outcomes after internally splinting the cancellous bone injuries of the femoral condyles and tibial plateaus with synthetic calcium phosphate bone substitute. As BMLs are often not isolated entities at the tibiofemoral articulation, it follows that the use of the same technique may be applied to the patellofemoral articulation when other pathologies are treated or used in other articulating areas of the knee, specifically the trochlea and patella. This article presents a proposed surgical technique to treat BMLs of these articulating areas.

Quantification of bone marrow lesion volume and volume change using semi-automated segmentation: data from the osteoarthritis initiative

BackgroundTo determine the validity of a semi-automated segmentation of bone marrow lesions (BMLs) in the knee.MethodsConstruct validity of the semi-automated BML segmentation method was explored in two studies performed using sagittal intermediate weighted, turbo spine echo, fat-suppressed magnetic resonance imaging sequences obtained from the Osteoarthritis Initiative. The first study (n = 48) evaluated whether tibia BML volume was different across Boston Leeds Osteoarthritis Knee Scores (BLOKS) for tibia BMLs (semiquantitative grades 0 to 3). In the second study (n = 40), we evaluated whether BML volume change was associated with changes in cartilage parameters. The knees in both studies were segmented by one investigator. We performed Wilcoxon signed-rank tests to determine if tibia BML volume was different between adjacent BLOKS BML scores and calculated Spearman correlation coefficients to assess the relationship between 2-year BML volume change and 2-year cartilage morphometry change (significance was p ≤ 0.05).ResultsBML volume was significantly greater between BLOKS BML score 0 and 1 (z = 2.85, p = 0.004) and BLOKS BML scores 1 and 2 (z = 3.09, p = 0.002). There was no significant difference between BLOKS BML scores 2 and 3 (z = −0.30, p = 0.77). Increased tibia BML volume was significantly related to increased tibia denuded area (Spearman r = 0.42, p = 0.008), decreased tibia cartilage thickness (Spearman r = −0.46, p = 0.004), increased femur denuded area (Spearman r = 0.35, p = 0.03), and possibly decreased femur cartilage thickness (Spearman r = −0.30, p = 0.07) but this last finding was not statistically significant.ConclusionThe new, efficient, and reliable semi-automated BML segmentation method provides valid BML volume measurements that increase with greater BLOKS BML scores and confirms previous reports that BML size is associated with longitudinal cartilage loss.

Bone marrow lesion volume reduction is not associated with improvement of other periarticular bone measures: data from the Osteoarthritis Initiative

IntroductionWe evaluated the associations between bone marrow lesion (BML) volume change and changes in periarticular bone mineral density (paBMD) as well as subchondral sclerosis to determine whether BML change is associated with other local bone changes.MethodsThe convenience sample comprised participants in the Osteoarthritis Initiative (OAI) with weight-bearing posterior-anterior knee radiographs and magnetic resonance images (MRIs) at the 24- and 48-month visits and dual-energy x-ray absorptiometry (DXA) at the 30-/36-month and 48-month visits. The right knee was assessed unless contraindicated for MRI. We used knee DXA scans to measure medial tibia paBMD and medial/lateral paBMD ratio (M:L paBMD). Knee radiographs were scored for sclerosis (grades 0 to 3) in the medial tibia. Two raters determined BML volume on sagittal fat-suppressed MRI by using a semiautomated segmentation method. To focus on knees with only medial tibia BML changes, knees with lateral tibial BMLs were excluded. Medial tibial BML volume change was classified into three groups: BML regression (lowest quartile of medial tibial BML volume change), no-to-minimal change (middle two quartiles), and BML progression (highest quartile). We used proportional odds logistic regression models to evaluate the association between quartiles of changes in medial paBMD or M:L paBMD ratio, as outcomes, and BML volume change.ResultsThe sample (n = 308) included 163 (53%) female subjects, 212 (69%) knees with radiographic osteoarthritis, and participants with a mean age of 63.8 ± 9.3 years and mean body mass index of 29.8 ± 4.7 kg/m2. We found an association between greater increases in medial tibia paBMD and BML regression (OR = 1.7 (95% confidence interval (CI) = 1.1 to 2.8)) and a similar trend for BML progression (OR = 1.6 (95% CI = 1.0 to 2.6]). We also detected associations between greater increase in M:L paBMD and BML regression (OR = 1.6 (95% CI = 1.0 to 2.7]) and BML progression (OR = 1.8 (95% CI = 1.1 to 3.0)), although BML regression had borderline statistical significance. The frequency of sclerosis progression in the medial tibia (n = 14) was greater among knees with BML progression or regression compared with knees without BML change (P = 0.01 and P = 0.04, respectively).ConclusionBML regression and BML progression are characterized by concurrent increases in paBMD and sclerosis, which are characteristic of increased radiographic osteoarthritis severity. At least during 24 months, BML regression is not representative of improvement in other periarticular bone measures.