Transient osteoporosis: transient bone marrow edema?

Ten patients with debilitating hip or knee pain were examined with magnetic resonance (MR) imaging. All had conventional radiographs that were either normal or showed nonspecific osteopenia. Nine patients had bone scintigrams that showed focal increased radionuclide uptake in the region of the painful joint. In each case, MR images of the affected joint showed regional decreased signal intensity of the bone marrow on T1-weighted images and increased signal intensity on T2-weighted images. Biopsy results of four patients excluded ischemic necrosis and metastases. The symptoms resolved spontaneously in all cases. The ten patients were followed up for 12-36 months, and there were no recurrences. The authors believe that the findings on MR images represent a transient increase in bone marrow water content. The focal findings on scintigrams confirmed the periarticular distribution of the process and provided evidence of accompanying hyperemia and increased bone mineral metabolism. For lack of a better term and to emphasize the generic character of the condition, the authors termed this condition "the transient marrow edema syndrome."

Characteristic magnetic resonance imaging entheseal changes of knee synovitis in spondylarthropathy

OBJECTIVE

To use magnetic resonance imaging (MRI) in patients with rheumatoid arthritis (RA) and spondylarthropathy (SpA) to determine if the primary site of abnormality differs.

METHODS

Twenty patients with recent-onset knee effusion (10 with SpA and 10 with RA) were evaluated using fat-suppressed MRI. Knee joint effusion and synovitis were confirmed using ultrasonography. MRI scans were independently scored by 2 observers who were blinded to the patient's diagnosis.

RESULTS

All 10 of the SpA patients, but only 4 of the 10 RA patients, had focal peri-entheseal high signal (compatible with fluid or edema) outside the joint (P = 0.01). Six of the SpA patients had bone marrow edema that was maximal at entheseal insertions; in 4 cases this was multifocal. No RA patients showed such an abnormality (P = 0.01).

CONCLUSION

Prominent entheseal abnormalities on MRI are a consistent feature of new-onset synovitis in SpA, but are a minor feature of RA. This finding has important implications for the diagnosis, classification, and mechanisms of synovitis in patients with SpA.

Magnetic resonance imaging findings in 84 patients with early rheumatoid arthritis: bone marrow oedema predicts erosive progression

OBJECTIVES

To examine the spectrum and severity of magnetic resonance imaging (MRI) findings in patients with early rheumatoid arthritis (RA), and to investigate the predictive value of MRI findings for subsequent development of conventional radiographic (CR) damage and MRI erosions.

METHODS

84 consecutive patients with RA with disease duration <1 year were enrolled. Patients were treated according to standard clinical practice, and evaluated at baseline, 3, 6 and 12 months by core measures of disease activity, conventional radiographs of both hands and wrists and MRI of the dominant wrist. MR images were scored according to the OMERACT rheumatoid arthritis magnetic resonance imaging score (RAMRIS), and conventional radiographs according to the van der Heijde modified Sharp score.

RESULTS

MRI findings reflecting inflammation (synovitis, bone marrow oedema and tenosynovitis) decreased during follow-up, while there was a small increase in MRI erosion score and CR damage. The proportion of patients with erosive progression at 1 year was 48% for conventional radiography and 66% for MRI. Baseline MRI bone marrow oedema (score >2 RAMRIS units) was identified as an independent predictor of both CR (odds ratio = 2.77 (95% confidence interval (CI) 1.06 to 7.21)) and MRI erosive progression (B = 0.21 (95% CI 0.08 to 0.34)).

CONCLUSIONS

MRI findings were common in early RA, and MRI bone marrow oedema was an independent predictor of radiographic damage. These results suggest that MRI scans of the dominant wrist may help clinicians to determine which patients need early and aggressive treatment to avoid subsequent joint damage.

MRI in the detection of malignant infiltration of bone marrow

Magnetic resonance imaging (MRI) at 0.35 T with a superconductive magnet was performed on 80 patients with known or suspected malignant disease of the bone marrow. The group comprised 50 patients with known primary malignancy and 30 with known multiple myeloma. The MRI scan was correlated with plain films and radionuclide bone scans. In 40 patients with suspected metastatic disease, areas of decreased signal intensity on T1-weighted spin-echo images were observed. Ten patients had no MRI evidence of metastasis, and the abnormalities suspected on bone scanning were shown to be due to other causes. All the myeloma patients had abnormalities demonstrated by MRI. This was significant, since most had normal bone scans. All diagnoses were confirmed by needle biopsy. MRI was shown to be a sensitive method of detecting areas of malignancy within the bone marrow toward which biopsy could be directed.

Optimised, low cost, low field dedicated extremity MRI is highly specific and sensitive for synovitis and bone erosions in rheumatoid arthritis wrist and finger joints: comparison with conventional high field MRI and radiography

OBJECTIVE

To evaluate a low field dedicated extremity MRI unit for detection of bone erosions, synovitis, and bone marrow oedema in wrist and metacarpophalangeal (MCP) joints, with a high field MRI unit as the standard reference.

METHODS

In 37 patients with RA and 28 healthy controls MRI of the wrist and 2nd-5th MCP joints was performed on a low field MRI unit (0.2 T Esaote Artoscan) and a high field MRI unit (1.0 T Siemens Impact) on 2 subsequent days. MRI was performed and evaluated according to OMERACT recommendations. Additionally, conventional x ray, clinical, and biochemical examinations were performed. In an initial low field MRI "sequence selection phase", based on a subset of 10 patients and 10 controls, sequences for comparison with high field MRI were selected.

RESULTS

With high field, spin echo MRI considered as the reference method, the sensitivity, specificity, and accuracy of low field 3D gradient echo MRI for erosions were 94%, 93%, 94%, while the corresponding values for x ray examination were 33%, 98%, and 83%. Sensitivity, specificity, and accuracy of low field MRI for synovitis were 90%, 96%, and 94%, and for bone marrow oedema 39%, 99%, and 95%. Intraclass correlation coefficients between low field and high field scores were 0.936 (p<0.005) for bone erosions and 0.923 (p<0.05) for synovitis.

CONCLUSION

Low field MRI provides high accuracy for detection and grading of erosions and synovitis, with high field MRI as the standard reference. For bone marrow oedema, specificity is high, but sensitivity only moderate. Low cost, patient compliant, low field dedicated extremity MRI provides similar information on bone erosions and synovitis as expensive high field MRI units.

Comparing the effects of tofacitinib, methotrexate and the combination, on bone marrow oedema, synovitis and bone erosion in methotrexate-naive, early active rheumatoid arthritis: results of an exploratory randomised MRI study incorporating semiquantitative and quantitative techniques

OBJECTIVES

To explore the effects of tofacitinib-an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA)-with or without methotrexate (MTX), on MRI endpoints in MTX-naive adult patients with early active RA and synovitis in an index wrist or hand.

METHODS

In this exploratory, phase 2, randomised, double-blind, parallel-group study, patients received tofacitinib 10 mg twice daily + MTX, tofacitinib 10 mg twice daily + placebo (tofacitinib monotherapy), or MTX + placebo (MTX monotherapy), for 1 year. MRI endpoints (Outcome Measures in Rheumatology Clinical Trials RA MRI score (RAMRIS), quantitative RAMRIS (RAMRIQ) and dynamic contrast-enhanced (DCE) MRI) were assessed using a mixed-effect model for repeated measures. Treatment differences with p<0.05 (vs MTX monotherapy) were considered significant.

RESULTS

In total, 109 patients were randomised and treated. Treatment differences in RAMRIS bone marrow oedema (BME) at month 6 were -1.55 (90% CI -2.52 to -0.58) for tofacitinib + MTX and -1.74 (-2.72 to -0.76) for tofacitinib monotherapy (both p<0.01 vs MTX monotherapy). Numerical improvements in RAMRIS synovitis at month 3 were -0.63 (-1.58 to 0.31) for tofacitinib + MTX and -0.52 (-1.46 to 0.41) for tofacitinib monotherapy (both p>0.05 vs MTX monotherapy). Treatment differences in RAMRIQ synovitis were statistically significant at month 3, consistent with DCE MRI findings. Less deterioration of RAMRIS and RAMRIQ erosive damage was seen at months 6 and 12 in both tofacitinib groups versus MTX monotherapy.

CONCLUSIONS

These results provide consistent evidence using three different MRI technologies that tofacitinib treatment leads to early reduction of inflammation and inhibits progression of structural damage.

TRIAL REGISTRATION NUMBER

NCT01164579.

Effect of Intravenous Zoledronic Acid on Tibiofemoral Cartilage Volume Among Patients With Knee Osteoarthritis With Bone Marrow Lesions: A Randomized Clinical Trial

IMPORTANCE

A proof-of-principle study suggested that intravenous zoledronic acid may reduce knee pain and the size of bone marrow lesions in people with knee osteoarthritis, but data from large trials are lacking.

OBJECTIVE

To determine the effects of intravenous zoledronic acid on knee cartilage volume loss in patients with symptomatic knee osteoarthritis and bone marrow lesions.

DESIGN, SETTING, AND PARTICIPANTS

A 24-month multicenter, double-blind placebo-controlled randomized clinical trial conducted at 4 sites in Australia (1 research center and 3 hospitals). Adults aged 50 years or older with symptomatic knee osteoarthritis and subchondral bone marrow lesions detected by magnetic resonance imaging (MRI) were enrolled from November 2013 through September 2015. The final date of follow-up was October 9, 2017.

INTERVENTIONS

Intravenous infusion with either 5 mg of zoledronic acid in a 100-mL saline solution (n = 113) or a placebo saline solution (n = 110) at baseline and 12 months.

MAIN OUTCOMES AND MEASURES

The primary outcome was absolute change in tibiofemoral cartilage volume assessed using MRI over 24 months (the minimum clinically important difference [MCID] has not been established). Three prespecified secondary outcomes were change in knee pain assessed by a visual analog scale (0 [no pain] to 100 [unbearable pain]; MCID, 15) and the Western Ontario and McMaster Universities Osteoarthritis Index (0 [no pain] to 500 [unbearable pain]; MCID, 75) over 3, 6, 12, 18, and 24 months and change in bone marrow lesion size over 6 and 24 months (the MCID has not been established).

RESULTS

Of 223 participants enrolled (mean age, 62.0 years [SD, 8.0 years]; 52% were female), 190 (85%) completed the trial. Change in tibiofemoral cartilage volume was not significantly different between the zoledronic acid group and the placebo group over 24 months (-878 mm3 vs -919 mm3; between-group difference, 41 mm3 [95% CI, -79 to 161 mm3]; P = .50). No significant between-group differences were found for any of the prespecified secondary outcomes, including changes in knee pain assessed by a visual analog scale (-11.5 in the zoledronic acid group vs -16.8 in the placebo group; between-group difference, 5.2 [95% CI, -2.3 to 12.8]; P = .17), changes in knee pain assessed by the Western Ontario and McMaster Universities Osteoarthritis Index (-37.5 vs -58.0, respectively; between-group difference, 20.5 [95% CI, -11.2 to 52.2]; P = .21), and changes in bone marrow lesion size (-33 mm2 vs -6 mm2; between-group difference, -27 mm2 [95% CI, -127 to 73 mm2]; P = .60) over 24 months. Adverse events were more common with zoledronic acid than with placebo (96% vs 83%, respectively) and consisted mainly of acute reactions (defined as symptoms within 3 days of administration of infusion; 87% vs 56%).

CONCLUSIONS AND RELEVANCE

Among patients with symptomatic knee osteoarthritis and bone marrow lesions, yearly zoledronic acid infusions, compared with placebo, did not significantly reduce cartilage volume loss over 24 months. These findings do not support the use of zoledronic acid in the treatment of knee osteoarthritis.

TRIAL REGISTRATION

anzctr.org.au Identifier: ACTRN12613000039785.

Association between patella alta and the prevalence and worsening of structural features of patellofemoral joint osteoarthritis: the multicenter osteoarthritis study

OBJECTIVE

To examine the relationship between patella alta and the prevalence and worsening at followup of structural features of patellofemoral joint (PFJ) osteoarthritis (OA) on magnetic resonance imaging (MRI).

METHODS

The Multicenter Osteoarthritis Study is a cohort study of persons ages 50-79 years with or at risk for knee OA. Patella alta was measured using the Insall-Salvati ratio (ISR) on the baseline lateral radiograph, and cartilage damage, bone marrow lesions (BMLs), and subchondral bone attrition (SBA) were graded on MRI at baseline and at 30 months of followup in the PFJ. We examined the association of the ISR with the prevalence and worsening of cartilage damage, BMLs, and SBA in the PFJ using logistic regression.

RESULTS

A total of 907 knees were studied (mean age 62 years, body mass index 30 kg/m(2), ISR 1.10), 63% from female subjects. Compared with knees in the lowest ISR quartile at baseline, those in the highest quartile had 2.4 (95% confidence interval [95% CI] 1.7-3.3), 2.9 (95% CI 2.0-4.3), and 3.5 (95% CI 2.3-5.5) times the odds of having lateral PFJ cartilage damage, BMLs, and SBA, respectively, and 1.5 (95% CI 1.1-2.0), 1.3 (95% CI 0.9-1.8), and 2.2 (95% CI 1.4-3.4) times the odds of having medial PFJ cartilage damage, BMLs, and SBA, respectively. Similarly, those with high ISRs were also at risk for worsening of cartilage damage and BMLs over time than those with low ISRs.

CONCLUSION

A high ISR, indicative of patella alta, is associated with structural features of OA in the PFJ. Additionally, the same knees have an increased risk of worsening of these same features over time.

Frequency of MRI changes suggestive of axial spondyloarthritis in the axial skeleton in a large population-based cohort of individuals aged <45 years

OBJECTIVE

To investigate the frequency of bone marrow oedema (BME) and fatty lesions (FL) suggestive of axial spondyloarthritis (axSpA) on MRI of the spine and sacroiliac joints (SIJ) in a general population sample.

METHODS

As part of a community-based cohort project (Study of Health in Pomerania), volunteers underwent spinal (sagittal T1/T2) and SIJ (semicoronal short tau inversion recovery) MRI examinations. Two calibrated readers evaluated the images to detect BME in SIJ and vertebral corners (VC) and FL in VC suggestive of axSpA using Assessment of SpondyloArthritis international Society definitions.

RESULTS

MRIs of 793 volunteers (49.4% males, mean age 37.3±6.3 years, 8.4% human leucocyte antigen-B27+) aged <45 years were evaluated. SIJ BME was seen in 136 (17.2%), VC BME in 218 (27.5%) and FL in 645 (81.4%) volunteers. SIJ BME in ≥1, ≥3 and ≥5 SIJ quadrants was seen in 136 (17.2%), 7 (0.9%) and 1 (0.1%) volunteers, respectively. In VC, BME≥1, ≥3 and ≥5 lesions were seen in 218 (27.5%), 38 (4.8%) and 6 (0.8%) volunteers, respectively, while FL≥1, ≥3 and ≥5 were seen in 645 (81.3%), 351 (44.3%) and 185 (23.3%) volunteers, respectively. Logistic regression analysis showed that BME and FL in VC were related to increasing age: OR 1.33, 95% CI 1.02 to 1.72, and OR 1.73, 95% CI 1.32 to 2.27, per decade increase, respectively.

CONCLUSIONS

In this large population-based study, a high frequency of inflammatory and fatty MRI lesions suggestive of axSpA was found, especially in the spine. This indicates a limited value of such MRI findings for diagnosis and classification of axSpA. The increasing frequency with age suggests that mechanical factors could play a role.

Diagnostic performance of dual-energy CT for the detection of bone marrow oedema: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review and meta-analysis was to assess the sensitivity and specificity of dual-energy CT (DECT) for the detection of bone marrow oedema (BME).

METHODS

An electronic search of the PubMed and EMBASE databases was conducted. Bivariate modelling and hierarchical summary receiver-operating characteristic modelling were performed to evaluate the overall diagnostic performance of DECT for BME. Subgroup analysis was performed according to the assessment type (qualitative vs. quantitative) and anatomical location (spine vs. appendicular skeleton). Meta-regression analyses were performed according to the subject, study, and DECT characteristics.

RESULTS

Twelve eligible studies (1901 lesions, 450 patients) were included. DECT exhibited a pooled sensitivity of 0.85 [95% confidence interval (CI): 0.78-0.90] and a pooled specificity of 0.97 (95% CI: 0.92-0.98) for BME detection. In addition, the diagnostic performance of qualitative assessment (sensitivity, 0.85; specificity, 0.97) was higher than that of quantitative assessment (sensitivity, 0.84; specificity, 0.88) of DECT findings. The diagnostic performance of DECT for the spine (sensitivity, 0.84; specificity, 0.98) and appendicular skeleton (sensitivity, 0.84; specificity, 0.93) were excellent. According to meta-regression analysis, the use of a tin filter, ≥ 2 image planes, and a slice thickness < 1 mm tended to exhibit higher sensitivity and hyperacute stage BME (< 24 h) tended to exhibit lower sensitivity.

CONCLUSIONS

These findings indicate that DECT has excellent sensitivity and specificity for BME detection. Qualitative assessment of DECT findings obtained using a tin filter, ≥ 2 image planes, and a 0.5-1-mm slice thickness in the acute stage BME (≥24 h) is recommended for more sensitive diagnosis.

KEY POINTS

• Overall, DECT is useful for the detection of BME (sensitivity, 85%; specificity-97%). • Qualitative assessment (sensitivity-85%; specificity-97%) is more accurate than quantitative assessment (sensitivity-84%; specificity-88%). • DECT showed excellent diagnostic performance for both the spine/appendicular skeleton (sensitivity-84%/84%; specificity-98%/93%).

High prevalence of spondyloarthritis-like MRI lesions in postpartum women: a prospective analysis in relation to maternal, child and birth characteristics

OBJECTIVES

Bone marrow oedema (BMO) on MRI of sacroiliac joints (SIJs) represents a hallmark of axial spondyloarthritis (SpA), yet such lesions may also occur under augmented mechanical stress in healthy subjects. We therefore sought to delineate the relationship between pregnancy/delivery and pelvic stress through a prospective study with repeated MRI. Results were matched with maternal, child and birth characteristics.

METHODS

Thirty-five women underwent a baseline MRI-SIJ within the first 10 days after giving birth. MRI was repeated after 6 months and, if positive for sacroiliitis according to the Assessment of SpondyloArthritis International Society (ASAS) definition, after 12 months. BMO and structural lesions were scored by three trained readers using the Spondyloarthritis Research Consortium of Canada (SPARCC) method.

RESULTS

Seventy-seven per cent of the subjects (27/35) displayed sacroiliac BMO immediately postpartum, 60% fulfilled the ASAS definition of a positive MRI. After 6 months, 46% of the subjects (15/33) still showed BMO, representing 15% (5/33) with a positive MRI. After 12 months, MRI was still positive in 12% of the subjects (4/33). Few structural lesions were detected. Intriguingly, in this study, the presence of BMO was related to a shorter duration of labour and lack of epidural anaesthesia.

CONCLUSION

A surprisingly high prevalence of sacroiliac BMO occurs in women immediately postpartum. Our data reveal a need for a waiting period of at least 6 months to perform an MRI-SIJ in postpartum women with back pain. This study also underscores the importance of interpreting MRI-SIJ findings in the appropriate clinical context.

Diffusion imaging of the vertebral bone marrow

Diffusion-weighted MRI (DWI) of the vertebral bone marrow is a clinically important tool for the characterization of bone-marrow pathologies and, in particular, for the differentiation of benign (osteoporotic) and malignant vertebral compression fractures. DWI of the vertebral bone marrow is, however, complicated by some unique MR and tissue properties of vertebral bone marrow. Due to both the spongy microstructure of the trabecular bone and the proximity of the lungs, soft tissue, or large vessels, substantial magnetic susceptibility variations occur, which severely reduce the magnetic field homogeneity as well as the transverse relaxation time T^*₂ , and thus complicate MRI in particular with echoplanar imaging (EPI) techniques. Therefore, alternative diffusion-weighting pulse sequence types such as single-shot fast-spin-echo sequences or segmented EPI techniques became important alternatives for quantitative DWI of the vertebral bone marrow. This review first describes pulse sequence types that are particularly important for DWI of the vertebral bone marrow. Then, data from 24 studies that made diffusion measurements of normal vertebral bone marrow are reviewed; summarizing all results, the apparent diffusion coefficient (ADC) of normal vertebral bone marrow is typically found to be between 0.2 and 0.6 × 10^-3  mm² /s. Finally, DWI of vertebral compression fractures is discussed. Numerous studies demonstrate significantly greater ADCs in osteoporotic fractures (typically between 1.2 and 2.0 × 10^-3  mm² /s) than in malignant fractures or lesions (typically 0.7-1.3 × 10^-3  mm² /s). Alternatively, several studies used the (qualitative) image contrast of diffusion-weighted acquisitions for differentiation of lesion etiology: a very good lesion differentiation can be achieved, particularly with diffusion-weighted steady-state free precession sequences, which depict malignant lesions as hyperintense relative to normal-appearing vertebral bone marrow, in contrast to hypointense or isointense osteoporotic lesions. Copyright © 2015 John Wiley & Sons, Ltd.

The clinical use of radionuclide bone marrow imaging

Bone marrow aspiration and biopsy are excellent techniques for evaluating bone marrow, but this evaluation is limited to a small part of the total blood-forming organ. With the introduction of radionuclide bone marrow imaging, a simple technique became available that overcomes marrow sampling errors by giving a total body view of functioning marrow. Furthermore, the procedure is noninvasive and provides an atraumatic method for evaluating a number of clinical problems including a discrepancy between bone marrow histology and clinical status (possible marrow sampling error), the determination of amount of active marrow after radiation and chemotherapy when further therapy is being considered, detection of sites of extramedullary hematopoiesis, location of the optimal sites for bone marrow biopsy, the diagnosis and staging of diffuse hematologic disorders, detection of metastases, the diagnosis of bone marrow infarcts in hemolytic anemias, and detecting avascular necrosis of the femoral heads. There are two major classes of bone marrow agents: (1) those that are incorporated into the erythroid precursors such as radioiron and (2) colloids that are taken up by the reticuloendothelial system (RES). Indium-111 chloride was originally considered to be an erythropoietic agent but appears to share some properties of RES labels. The best label to use is dependent on the disease being evaluated.

Extrapulmonary Pneumocystis carinii infection in AIDS: CT findings

Clinical and computed tomographic (CT) findings in three cases of extrapulmonary Pneumocystis carinii infection in patients with acquired immunodeficiency syndrome (AIDS) were reviewed. Proved sites of involvement included the spleen (n = 2), bone marrow (n = 1), liver (n = 1), and peritoneal and pleural fluid (n = 1). CT findings included focal low-attenuation splenic lesions that became progressively calcified in rimlike or punctate fashion; punctate calcifications in the liver, renal cortices, and adrenal glands; calcification of lymph nodes; and pleural and peritoneal effusions with subsequent calcifications of the pleural and peritoneal surfaces. Although rare both before and since the onset of the AIDS epidemic, extrapulmonary P carinii infection in AIDS patients has been reported with increasing frequency in recent years, and more cases with radiologic manifestations should be expected.

Recent advances in bone marrow scanning

Interest in bone marrow scanning has been renewed as the result of the development of radiopharmaceuticals for evaluating specific aspects of bone marrow anatomy, physiology and pathology. This article provides a brief review of bone marrow structure, blood flow and function essential to the understanding of basic principles of bone marrow radionuclide imaging. The prospects and limitations of imaging haematopoietic bone marrow in man using indium 111 chloride, technetium-99m (99mTc)-labelled microcolloid or 99mTc-labelled monoclonal antigranulocytic and antimyelocytic antibodies are discussed in more detail. The technical aspects of bone marrow scintigraphy are presented. Results of more recent studies evaluating bone marrow scanning in circulatory, inflammatory and in systemic haematological disorders are summarized. Special attention is paid to the concept of bone marrow micrometastases and its implications for the follow-up of patients with malignant tumours. Recent results suggest that immunoscintigraphy of bone marrow may provide a novel and sensitive approach for establishing the presence and extent of bone marrow infiltration.

Bone marrow MRI: techniques and accuracy for detecting breast cancer metastases

We investigated the utility of bone marrow MRI for diagnosing marrow metastases from breast cancer compared with radionuclide bone scan, iliac crest marrow biopsy with histology and antibody immunostaining, and clinical follow-up. We report the results of 43 MRI studies in 32 patients and discuss the evolution and comparison of optimal MRI techniques. MRI appears to be the most accurate diagnostic method, and short TI Inversion Recovery (STIR) the most reliable pulse sequence for this group of patients with breast cancer.

Bone marrow lesions and synovitis on MRI associate with radiographic progression after 2 years in hand osteoarthritis

OBJECTIVE

To study the association of magnetic resonance (MR) features with radiographic progression of hand osteoarthritis over 2 years.

METHODS

Of 87 primary patients with hand osteoarthritis (82% women, mean age 59 years), baseline distal and proximal interphalangeal joint contrast-enhanced MR images were scored 0-3 for bone marrow lesions (BMLs) and synovitis following the Oslo score. Baseline and 2-year follow-up radiographs were scored following Kellgren-Lawrence (KL) (0-4) and OsteoArthritis Research Society International (OARSI) scoring methods (0-3 osteophytes, joint space narrowing (JSN)). Increase ≥1 defined progression. Associations between MR features and radiographic progression were explored on joint and on patient level, adjusting for age, sex, body mass index, synovitis and BML. Joints in end-stage were excluded.

RESULTS

Of 696 analysed joints, 324 had baseline KL=0, 28 KL=4 and after 2 years 78 joints progressed. BML grade 2/3 was associated with KL progression (2/3 vs 0: adjusted risk ratio (RR) (95% CI) 3.3 (2.1 to 5.3)) and with osteophyte or JSN progression, as was synovitis. Summated scores were associated with radiographic progression on patient level (RR crude BML 1.08 (1.01 to 1.2), synovitis 1.09 (1.04 to 1.1), adjusted synovitis 1.08 (1.03 to 1.1)).

CONCLUSIONS

BMLs, next to synovitis, show, already after 2 years, graded associations with radiographic progression, suggesting that both joint tissues could be important targets for therapy.

Avascular necrosis and bone marrow edema syndrome

MR imaging is the most accurate modality for the diagnosis of AVN, bone marrow edema syndrome, and femoral head insufficiency fractures. When the particular demographics of the patient are considered, the specificity of this examination is high. The reported success rates of joint-sparing operative intervention are variable. When compared with conservative management, the outcome of joint-sparing operative intervention in patients who have early (stage I, II) AVN lesions is improved. This is impetus for screening programs for patients who are known to be at high risk for AVN, such as patients who have undergone renal transplants and others who are on long-term, high-dose corticosteroid treatment. There is strong evidence that bone marrow edema syndrome (TO) is a distinct entity with demonstrable unique histopathology and well-defined demographics. Increased spatial resolution revealed typical subchondral findings of AVN in lesions that were once believed to represent irreversible TO. SIF of the femoral head is a new concept with a seemingly distinct population and with clinical presentation and imaging characteristics that should permit its differentiation from AVN.

Imaging features of intraosseous ganglia: a report of 45 cases

The aim of this study is to report the spectrum of imaging findings of intraosseous ganglia (IG) with particular emphasis on the radiographic and magnetic resonance (MR) features. Forty-five patients with a final diagnosis of IG were referred to a specialist orthopaedic oncology service with the presumptive diagnosis of either a primary or secondary bone tumour. The diagnosis was established by histology in 25 cases. In the remainder, the imaging features were considered characteristic and the lesion was stable on follow-up radiographic examination. Radiographs were available for retrospective review in all cases and MR imaging in 29. There was a minor male preponderance with a wide adult age range. Three quarters were found in relation to the weight-bearing long bones of the lower limb, particularly round the knee. On radiographs all were juxta-articular and osteolytic; 74% were eccentric in location, 80% had a sclerotic endosteal margin and 60% of cases showed a degree of trabeculation. Periosteal new bone formation and matrix mineralization were not present. Of the 29 cases that underwent MR imaging, 66% were multiloculated. On T1-weighted images the IG contents were isointense or mildly hypointense in 90% cases. Forty-one per cent of the cases showed a slightly hyperintense rim lining that enhanced with a gadolinium chelate. Thirty-eight per cent were associated with soft tissue extension and 17% with a defect of the adjacent articular cortex. Fifty-five per cent showed surrounding marrow oedema on T2-weighted or STIR images and two cases (7%) a fluid-fluid level prior to any surgical intervention. The authors contend that it is semantics to differentiate between an IG and a degenerate subchondral cyst as, while the initial pathogenesis may vary, the histological endpoint is identical, as are the imaging features apart from the degree of associated degenerative joint disease. IGs, particularly when large, may be mistaken for a bone tumour. Correlation of the typical radiographic and MR imaging features will indicate the correct diagnosis and obviate the need for biopsy.

Unsupervised Learning for Cell-Level Visual Representation in Histopathology Images With Generative Adversarial Networks

The visual attributes of cells, such as the nuclear morphology and chromatin openness, are critical for histopathology image analysis. By learning cell-level visual representation, we can obtain a rich mix of features that are highly reusable for various tasks, such as cell-level classification, nuclei segmentation, and cell counting. In this paper, we propose a unified generative adversarial networks architecture with a new formulation of loss to perform robust cell-level visual representation learning in an unsupervised setting. Our model is not only label-free and easily trained but also capable of cell-level unsupervised classification with interpretable visualization, which achieves promising results in the unsupervised classification of bone marrow cellular components. Based on the proposed cell-level visual representation learning, we further develop a pipeline that exploits the varieties of cellular elements to perform histopathology image classification, the advantages of which are demonstrated on bone marrow datasets.

Association between Bone marrow lesions & synovitis and symptoms in symptomatic knee osteoarthritis

OBJECTIVE

Bone marrow lesions (BMLs) on MRI are typically subchondral in location, however, a proportion occur at knee ligament attachments and also include a cyst-like component. Our aim was to determine whether the volume of BML subtypes and synovial tissue volume (STV) was associated with symptoms in symptomatic knee OA.

METHOD

Images were acquired in a sub-sample who had taken part in a randomised trial of vitamin D therapy in knee OA (UK-VIDEO). Contrast-enhanced (CE) MRI was performed annually. In those who had ≥1 follow-up and a baseline scan (N = 50), STV and BML volume was assessed. BMLs were categorised by location and by the presence/absence of a cyst-like component. WOMAC was assessed annually. We used fixed-effects panel-regression modelling to examine the association between volume and symptoms.

RESULTS

There was no association between knee pain and total subchondral BML volume (b = 0.3 WOMAC units, 95% CI -0.3 to 1.0) or total ligament-based BML volume (b = 1.9, 95% CI -1.6 to 5.3). The volume of subchondral BMLs with a cyst-like component was not associated with pain (b = 0.8, 95% CI -0.5 to 2.1) however, the volume of the cyst-like component itself was associated with pain (b = 51.8, 95% CI 14.2 to 89.3). STV was associated with pain (b = 2.2, 95% CI 0.6 to 3.7).

CONCLUSION

The volume of the cyst-like component from subchondral BMLs with a cyst-like component was associated with knee pain. BML location, however, did not influence symptoms. STV was also associated with knee symptoms.

The Presence and Degree of Bone Marrow Edema Influence Midterm Clinical Outcomes After Microfracture for Osteochondral Lesions of the Talus

BACKGROUND

Subchondral bone marrow edema (BME) has been associated with articular cartilage loss, with the potential to be a negative prognostic indicator for clinical outcomes after microfracture. However, no single study has investigated the association between BME and clinical outcomes after microfracture for osteochondral lesions of the talus (OLTs) at midterm follow-up.

PURPOSE

To clarify the association between postoperative subchondral BME and clinical outcomes in patients treated with microfracture for OLTs at both short-term and midterm follow-up using a grading system that classified the extent of BME of the talus.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients who underwent microfracture between 2008 and 2013 were assessed at 2- and 4-year postoperative follow-up. BME was evaluated using magnetic resonance imaging, and the presence of subchondral BME was determined with fat-suppressed T2-weighted sequences. Clinical outcomes were evaluated using the Foot and Ankle Outcome Score (FAOS). P < .05 was considered to be statistically significant.

RESULTS

Forty-three (83%) of 52 eligible patients were included. No significant differences were found in the FAOS between the BME and no BME groups at 2-year follow-up (83.1 ± 6.5 vs 88.6 ± 8.0, respectively; P = .109), but there was a significant difference at 4-year follow-up (77.5 ± 11.1 vs 84.7 ± 8.4, respectively; P = .041). A significant difference was found among BME grades at 4-year follow-up (grade 0: 84.7 ± 7.4, grade 1: 80.1 ± 10.5, grade 2: 74.0 ± 10.3, and grade 3: 67.5 ± 7.1; P = .035). A post hoc analysis showed significant differences between grades 0 and 2, 0 and 3, and 1 and 3 ( P = .041, .037, and .048, respectively). In addition, at 4-year follow-up, a significant correlation was noted between the FAOS and BME grade ( r = -0.453, P = .003) but not at 2-year follow-up ( r = -0.212, P = .178). Seventy-four percent of patients still had subchondral BME at 4-year follow-up after microfracture for OLTs.

CONCLUSION

Patients with subchondral BME at midterm follow-up after microfracture for OLTs had worse clinical outcomes than those without subchondral BME. In addition, the degree of subchondral BME at midterm follow-up was correlated with clinical outcomes. However, at short-term follow-up, there were no significant differences in clinical outcomes based on both the presence and degree of BME, and no correlation was found between clinical outcomes and the degree of BME. The current study suggests that BME at short-term follow-up is a normal physiological reaction. However, BME at midterm follow-up after microfracture for OLTs may be pathological and is associated with poorer clinical outcomes.

ASAS definition for sacroiliitis on MRI in SpA: applicable to children?

BACKGROUND

The Assessment of Spondyloarthritis International Society (ASAS) definition for a 'positive' Magnetic Resonance Imaging (MRI) for sacroiliitis is well studied and validated in adults, but studies about the value of this definition in children are lacking. The aim of this study is to evaluate whether the adult ASAS definition of a positive MRI of the sacroiliac joints can be applied to children with a clinical suspicion of Juvenile Spondyloarthritis (JSpA).

METHODS

Two pediatric musculoskeletal radiologists blinded to clinical data independently retrospectively reviewed sacroiliac (SI) joint MRI in 109 children suspected of sacroiliitis. They recorded global impression (sacroiliitis yes/no) and whether the adult ASAS definition for sacroiliitis was met at each joint. This was compared to gold-standard clinical diagnosis of JSpA. Additionally, MRI were scored according to'adapted' ASAS definitions including other features of sacroiliitis on MRI.

RESULTS

JSpA was diagnosed clinically in 47/109 (43%) patients. On MRI, sacroiliitis was diagnosed by global assessment in 30/109 patients, of whom 14 also fulfilled ASAS criteria. No patients with negative global assessment for sacroiliitis fulfilled ASAS criteria. Sensitivity (SN) for JSpA was higher for global assessment (SN = 49%) than for ASAS definition (SN = 26%), but the ASAS definition was more specific (SP = 97% vs. 89%). Modifying adult ASAS criteria to allow bone marrow edema (BME) lesions seen on only one slice, synovitis or capsulitis, increased SN to 36%, 32% and 32% respectively, only slightly lowering SP. Including structural lesions increased SN to 28%, but lowered specificity to 95%.

CONCLUSION

The adult ASAS definition for sacroiliitis has low sensitivity in children. A pediatric-specific definition of MRI-positive sacroiliitis including BME lesions visible on one slice only, synovitis and/or capsulitis may improve diagnostic utility, and increase relevance of MRI in pediatric rheumatology practice.

SPECT/CT versus MRI in patients with nonspecific pain of the hand and wrist - a pilot study

BACKGROUND

Hand and wrist pain is a diagnostic challenge for hand surgeons and radiologists due to the complex anatomy of the involved small structures. The American College of Radiology recommends MRI as the study of choice in patients with chronic wrist pain if radiographs are negative. Lately, state-of-the-art SPECT/CT systems have been introduced and may help in the diagnosis of this selected indication.

MATERIALS AND METHODS

This retrospective study included 21 patients with nonspecific pain of the hand/wrist. The diagnosis of nonspecific wrist pain was made by the referring hand surgeon based on patient history, clinical examination, plain radiography and clinical guidelines. All patients received planar early-phase imaging and late-phase SPECT/CT imaging as well as MRI. Lesions were divided into major (causative) and minor (not causative) pathologies according to clinical follow-up. Furthermore, oedema-like bone marrow changes seen on MRI were compared with focally increased tracer uptake seen on SPECT/CT images.

RESULTS

MRI yielded a quite high sensitivity (0.86), but a low specificity (0.20). In contrast, SPECT/CT yielded a high specificity (1.00) and a low sensitivity (0.71). Oedema-like bone marrow changes were detected in 15 lesions in 11 patients. In ten lesions with bone marrow oedema on MRI, foci of elevated tracer uptake were detected on SPECT/CT. Overall, MRI was more sensitive, but SPECT/CT was more specific in the evaluation of causative pathologies.

CONCLUSION

In this initial comparison, SPECT/CT showed higher specificity than MRI in the evaluation of causative pathologies in patients with nonspecific wrist pain. However, MRI was more sensitive. Thus, SPECT/CT was shown to be a useful problem-solving tool in the diagnostic work-up of these patients.