Quantitative MRI in myositis patients: comparison with healthy volunteers and radiological visual assessment.

AIM: To assess whether magnetic resonance imaging (MRI)-based measurements of T2, fat fraction, diffusion tensor imaging, and muscle volume can detect differences between the muscles of myositis patients and healthy controls, and to identify how they compare with semi-quantitative MRI diagnosis. MATERIALS AND METHODS: Sixteen myositis patients and 16 age- and gender-matched healthy controls underwent MRI of their thigh. Quantitative MRI measurements and radiologists' semi-quantitative scores were assessed. Strength was assessed using an isokinetic dynamometer. RESULTS: Fat fraction and T2 values were higher in myositis patients whereas muscle volume was lower compared to healthy controls. There was no difference in diffusion. Muscle strength was lower in myositis patients compared to healthy controls. In a subgroup of eight patients, scored as unaffected by radiologists, T2 values were still significantly higher in myositis patients. CONCLUSIONS: Quantitative MRI measurements can detect differences between myositis patients and healthy controls. Changes in the muscles of myositis patients, undetected by visual, semi-quantitative scoring, can be detected using quantitative T2 measurements. This suggests that MRI T2 values may be useful for the management of myositis patients.

MRI in acute muscle tears in athletes: can quantitative T2 and DTI predict return to play better than visual assessment?

OBJECTIVES: To assess the ability of quantitative T2, diffusion tensor imaging (DTI) and radiologist's scores to detect muscle changes following acute muscle tear in soccer and rugby players. To assess the ability of these parameters to predict return to play times. METHODS: In this prospective, longitudinal study, 13 male athletes (age 19 to 34 years; mean 25 years) underwent MRI within 1 week of suffering acute muscle tear. Imaging included measurements of T2 and DTI parameters. Images were also assessed using modified Peetrons and British athletics muscle injury classification (BAMIC) scores. Participants returned for a second scan within 1 week of being determined fit to return to play. MRI measurements were compared between visits. Pearson's correlation between visit 1 measurements and return to play times was assessed. RESULTS: There were significant differences between visits in BAMIC scores (Z = - 2.088; p = 0.037), modified Peetrons (Z = - 2.530; p = 0.011) and quantitative MRI measurements; T2, 13.12 ms (95% CI, 4.82 ms, 21.42 ms; p = 0.01); mean diffusivity (0.22 (0.04, 0.39); p = 0.02) and fractional anisotropy (0.07 (0.01, 0.14); p = 0.03). BAMIC scores showed a significant correlation with return to play time (Rs = 0.64; p = 0.02), but modified Peetrons scores and quantitative parameters did not. CONCLUSIONS: T2 and DTI measurements in muscle can detect changes due to healing following muscle tear. Although BAMIC scores correlated well with return to play times, in this small study, quantitative MRI values did not, suggesting that T2 and DTI measurements are inferior predictors of return to play time compared with visual scoring. KEY POINTS: • Muscle changes following acute muscle tear can be measured using T2 and diffusion measurements on MRI. • Measurements of T2 and diffusion using MRI are not as good as a radiologist's visual report at predicting return to play time after acute muscle tear.

Ultrasound and magnetic resonance imaging assessment of joint disease in symptomatic patients with cystic fibrosis arthropathy.

OBJECTIVES: Cystic fibrosis arthropathy (CFA) is a term commonly used for joint pain with and without swelling seen in some patients with CF. Early studies into CFA focused on the presence of rheumatoid factor and immunological changes on synovial biopsy, with parallels drawn between respiratory and joint activity. Identification of anti-cyclic citrullinated peptide antibodies (anti-CCP) as a marker of rheumatoid arthritis (RA), along with increased access to sensitive imaging techniques including ultrasound (US) and magnetic resonance imaging (MRI), offer great potential to investigate and more accurately understand the type(s) of inflammatory arthritis that may underlie CFA. The aim of this study was to phenotype an active CFA cohort using serology and imaging, as a basis for further work in this understudied area. METHODS: This was a prospective observational cohort study of symptomatic CFA patients presenting with joint pain. Participants underwent serological testing, clinical and US joint and entheseal assessment, as well as MRI of the most symptomatic joint/joint area. RESULTS: Ten symptomatic patients were studied with 9/10 having positive clinical findings. Inflammatory changes on US were seen in 8/10 cases. Five patients had positive findings on MRI (3 of whom had received IV gadolinium contrast). This included patients with significant erosive changes. One patient was anti-CCP positive suggestive of RA, and two were anti-nuclear antibody positive. CONCLUSION: Imaging, and to a lesser extent serology, identified inflammatory joint pathology in a proportion of cases, providing important data to explore in a large CFA cohort examining the clinical and imaging phenotype of this group.

The role of imaging modalities in the diagnosis, differential diagnosis and clinical assessment of peripheral joint osteoarthritis.

Peripheral joint osteoarthritis (OA) is predominantly a clinical diagnosis, though imaging may provide confirmation and aid with differential diagnosis where there is clinical doubt. Whilst radiographs (X-rays (XR)) are usually the first-line imaging modality selected, magnetic resonance imaging (MRI), ultrasound and computed tomography (CT) may all have a valuable role in assessing a person with OA, although each has its particular advantages and disadvantages. MRI is of particular use for diagnosing bone conditions that may cause a rapid increase in symptoms, such as avascular necrosis (AVN) or a subchondral insufficiency fracture (SIF), while providing concomitant soft tissue assessment. Ultrasound offers rapid assessment of peripheral joints and can easily assess for features of inflammatory arthritis. CT is faster to perform than MRI and can also image the subchondral bone, but does involve ionising radiation. Selecting the correct imaging modality, in the context of its advantages when visualising a specific joint (e.g., hand vs knee) and with clinical context in mind, will enhance the added value of imaging in clinical practice.

Litigation after hip and knee replacement in the National Health Service.

The results of hip and knee replacement surgery are generally regarded as positive for patients. Nonetheless, they are both major operations and have recognised complications. We present a review of relevant claims made to the National Health Service Litigation Authority. Between 1995 and 2010 there were 1004 claims to a value of £41.5 million following hip replacement surgery and 523 claims to a value of £21 million for knee replacement. The most common complaint after hip surgery was related to residual neurological deficit, whereas after knee replacement it was related to infection. Vascular complications resulted in the highest costs per case in each group.Although there has been a large increase in the number of operations performed, there has not been a corresponding relative increase in litigation. The reasons for litigation have remained largely unchanged over time after hip replacement. In the case of knee replacement, although there has been a reduction in claims for infection, there has been an increase in claims for technical errors. There has also been a rise in claims for non-specified dissatisfaction. This information is of value to surgeons and can be used to minimise the potential mismatch between patient expectation, informed consent and outcome.

Evolution of semi-quantitative whole joint assessment of knee OA: MOAKS (MRI Osteoarthritis Knee Score).

OBJECTIVE: In an effort to evolve semi-quantitative scoring methods based upon limitations identified in existing tools, integrating expert readers' experience with all available scoring tools and the published data comparing the different scoring systems, we iteratively developed the magnetic resonance imaging (MRI) Osteoarthritis Knee Score (MOAKS). The purpose of this report is to describe the instrument and its reliability. METHODS: The MOAKS instrument refines the scoring of bone marrow lesions (BMLs) (providing regional delineation and scoring across regions), cartilage (sub-regional assessment), and refines the elements of meniscal morphology (adding meniscal hypertrophy, partial maceration and progressive partial maceration) scoring. After a training and calibration session two expert readers read MRIs of 20 knees separately. In addition, one reader re-read the same 20 MRIs 4 weeks later presented in random order to assess intra-rater reliability. The analyses presented here are for both intra- and inter-rater reliability (calculated using the linear weighted kappa and overall percent agreement). RESULTS: With the exception of inter-rater reliability for tibial cartilage area (kappa=0.36) and tibial osteophytes (kappa=0.49); and intra-rater reliability for tibial BML number of lesions (kappa=0.54), Hoffa-synovitis (kappa=0.42) all measures of reliability using kappa statistics were very good (0.61-0.8) or reached near-perfect agreement (0.81-1.0). Only intra-rater reliability for Hoffa-synovitis, and inter-rater reliability for tibial and patellar osteophytes showed overall percent agreement <75%. CONCLUSION: MOAKS scoring shows very good to excellent reliability for the large majority of features assessed. Further iterative development and research will include assessment of its validation and responsiveness.

The reliability of a new scoring system for knee osteoarthritis MRI and the validity of bone marrow lesion assessment: BLOKS (Boston Leeds Osteoarthritis Knee Score).

AIM: MRI provides unparalleled visualisation of all the anatomical structures involved in the osteoarthritis (OA) process. There is a need for reliable methods of quantifying abnormalities of these structures. The aim of this work was to assess the reliability of a novel MRI scoring system for evaluating OA of the knee and explore the validity of the bone marrow lesion (BML) scoring component of this new tool. METHODS: After review of the relevant literature, a collaborative group of rheumatologists and radiologists from centres in the UK and USA established preliminary anatomical divisions, items (necessarily broadly inclusive) and scaling for a novel semi-quantitative knee score. A series of iterative reliability exercises were performed to reduce the initial items, and the reliability of the resultant Boston-Leeds Osteoarthritis Knee Score (BLOKS) was examined. A further sample had both the BLOKS and WORMS (Whole Organ MRI Score) bone marrow lesion (BML) score performed to assess the construct validity (relation to knee pain) and longitudinal validity (prediction of cartilage loss) of each scoring method. RESULTS: The BLOKS scoring method assesses nine intra-articular regions and contains eight items, including features of bone marrow lesions, cartilage, osteophytes, synovitis, effusions and ligaments. The scaling for each feature ranges from 0-3. The inter-reader reliability for the final BLOKS items ranged from 0.51 for meniscal extrusion up to 0.79 for meniscal tear. The reliability for other key features was 0.72 for BML grade, 0.72 for cartilage morphology, and 0.62 for synovitis. Maximal BML size on the BLOKS scale had a positive linear relation with visual analogue scale (VAS) pain, however the WORMS scale did not. Baseline BML was associated with cartilage loss on both BLOKS and WORMS scale. This association was stronger for BLOKS than WORMS. CONCLUSION: We have designed a novel scoring system for MRI OA knee, BLOKS, that demonstrates good reliability. Preliminary inspection of the validity of one of the components of this new tool supports the validity of the BLOKS BML scoring method over an existing instrument. Further iterative development will include validation for use in both clinical trials and epidemiological studies.

Can ultrasonography improve on radiographic assessment in osteoarthritis of the hands? A comparison between radiographic and ultrasonographic detected pathology.

OBJECTIVES: Ultrasonography (US) is used in rheumatology to assess small joints in inflammatory arthritis. Recently there has been some investigation into the utility of US in osteoarthritis (OA), however there has been little comparison of US to other imaging modalities in OA. This study aimed to compare the detection of osteophytosis and joint space narrowing (JSN) by US and conventional radiography (CR) in OA of the hand. SUBJECTS: with OA of the hand underwent US and CR examination of the small joints of both hands to identify osteophytosis and joint space narrowing. RESULTS: 1106 joints of 37 patients were imaged with US and CR. US detected osteophytosis in 448 joints, compared to CR that detected osteophytosis in 228 joints (approximately 30% fewer joints). Where osteophytosis was detected by US but not CR, this was usually proximal to the joint line. Joint space narrowing was detected in 450 joints by US, but only 261 joints by CR. The distribution of US and CR detected osteoarthritis changes in this cohort was consistent with population studies of radiographic hand OA, although metacarpophalangeal (MCP) involvement was higher than might be expected CONCLUSIONS: US detected more osteophytosis and joint space narrowing than CR in OA of the hand. Involvement of MCP joints was more common than would be expected from population radiographic studies. The increased detection of OA structural pathology by US may make this a useful tool for hand OA research.

The relationship between limited MRI section analyses and volumetric assessment of synovitis in knee osteoarthritis.

AIM: To assess whether simple, limited section analysis can replace detailed volumetric assessment of synovitis in patients with osteoarthritis (OA) of the knee using contrast-enhanced magnetic resonance imaging (MRI). MATERIALS AND METHODS: Thirty-five patients with clinical and radiographic OA of the knee were assessed for synovitis using gadolinium-enhanced MRI. The volume of enhancing synovium was quantitatively assessed in four anatomical sites (the medial and lateral parapatellar recesses, the intercondylar notch and the suprapatellar pouch) by summing the volumes of synovitis in consecutive sections. Four different combinations of section analysis were evaluated for their ability to predict total synovial volume. RESULTS: A total of 114 intra-articular sites were assessed. Simple linear regression demonstrated that the best predictor of total synovial volume was the analysis containing the inferior, mid and superior sections of each of the intra-articular sites, which predicted between 40-80% (r(2) = 0.396, p < 0.001 for notch; r(2) = 0.818, p < 0.001 for medial parapatellar recess) of the total volume assessment. CONCLUSIONS: The results suggest that a three-section analysis on axial post-gadolinium sequences provides a simple surrogate measure of synovial volume in OA knees.

The evaluation of a new digital semi-automated system for the radiological assessment of distal radial fractures.

OBJECTIVE: To compare intra- and inter-observer variation for measurements of wrist deformity using a manual method of measurement and a semi-automated digital system developed in our department. DESIGN: Four observers measured radial angle, radial shift, radial length, palmar tilt, and dorsal shift on ten wrist-fracture films using a standardised protocol. Each observer made measurements directly from the radiograph on three occasions, and on a further three occasions digitised images were viewed and measurements made with semi-automated on-screen measurement tools. RESULTS: Manual measurements took 12 min per case compared with 3 min for the digital system. The digital system resulted in improved intra-observer variation for all measurements and an improvement in inter-observer variation for all measurements except posterior tilt. CONCLUSION: The new system allows greater precision in assessing fracture reduction and follow-up. Its principal application is in studies that utilise the wrist as a model for fracture healing.

A radiological technique for the assessment of wear in prosthetic knee replacements.

OBJECTIVE: Wear of the polyethylene insert is a well-recognised cause of implant failure in total knee replacements. The purpose of this study was to evaluate a simple, digital fluoroscopic technique for the assessment of wear in knee prostheses. DESIGN: Fluoroscopic images of knee prostheses were produced both of a phantom and in a patient group. Joint space thickness was measured by reference to a known diameter. Measurements were made to assess repeatability of positioning, inter-and intra-observer variance and the effect of angulation. RESULTS: Standard phantom images showed small variation between measurements, high inter-reader correlation (Pearson's correlation coefficient, r=0.98, P<0.001; coefficient of variation=0.53%) and low intra-reader variation (coefficient of variation=0.57%). Inter- and intra-imager variation were low (coefficient of variation=1.05% and 0.88%, respectively). In the patient group, the range of joint space measurements was 1.9-8.9 mm. The coefficient of variation in insert measurements on repeated images was 2.0%. Repeatability of measurements was 0.2 mm with 99% confidence interval. CONCLUSIONS: This technique allows repeatable, precise measurement of insert thickness. The technique may be adapted to any implant where a reliable calibrating distance is present.