Atlas of MRI findings of sacroiliitis in pediatric sacroiliac joints to accompany the updated preliminary OMERACT pediatric JAMRIS (Juvenile Idiopathic Arthritis MRI Score) scoring system: Part I: Active lesions.

Magnetic resonance imaging (MRI) is an increasingly important tool for identifying involvement of the sacroiliac joints (SIJ) in juvenile idiopathic arthritis (JIA). The key feature for diagnosing active sacroiliitis is bone marrow edema (BME), but other features of active arthritis such as joint space inflammation, inflammation in an erosion cavity, capsulitis and enthesitis can be seen as well. Structural changes may also be seen. Systematic MRI assessment of inflammation and structural damage may aid in monitoring the disease course, choice of therapeutics and evaluating treatment response. In this pictorial essay, we illustrate normal MRI findings and growth-related changes of the SIJ in the pediatric population, as well as the different MRI features of SIJ inflammation. This atlas demonstrates fundamental MRI disease features of active inflammation in a format that can serve as a reference for assessing SIJ arthritis according to the updated preliminary JAMRIS (Juvenile Idiopathic Arthritis MRI Score) scoring system proposed by the MRI in JIA working group of Outcome Measures in Rheumatology and Clinical Trials (OMERACT). The atlas is intended to be read in conjunction with its companion Part 2, Structural Lesions.

Atlas of MRI findings of sacroiliitis in pediatric sacroiliac joints to accompany the updated preliminary OMERACT pediatric JAMRIS (Juvenile Idiopathic Arthritis MRI Score) scoring system: Part II: Structural damage lesions.

Magnetic resonance imaging (MRI) is the imaging modality of choice for identifying sacroiliitis in juvenile idiopathic arthritis (JIA). Besides active lesions of sacroiliitis, of which bone marrow edema (BME) is the key feature, structural damage lesions can also be detected. Structural changes include erosion, sclerosis, fat lesion, backfill and ankylosis, and are more common at later stages. Systematic MRI assessment of inflammation and structural damage may aid in monitoring the course of the disease and evaluating treatment options. In this pictorial essay, we illustrate normal MRI findings and growth-related changes of the SIJ in the pediatric population, as well as the different MRI features of structural damage of sacroiliitis. This atlas can serve as a reference for assessing structural lesions of SIJ arthritis according to the updated preliminary JAMRIS (Juvenile Idiopathic Arthritis MRI Score) scoring system proposed by the MRI in JIA working group of Outcome Measures in Rheumatology and Clinical Trials (OMERACT). The atlas is intended to be read in conjunction with its companion Part 1, Active Lesions.

Inter-rater reliability of the radiographic assessment of simple bone cysts.

PURPOSE: To develop and evaluate the reliability of an explicit set of parameters and criteria for simple bone cysts (SBCs) and evaluate the reliability of single versus serial chronological reading methods. METHODS: Radiographic criteria were developed based on the literature and expert consensus. A single anteroposterior/lateral radiograph from 32 subjects with SBC were evaluated by three radiologists. A second reading was then conducted using revised criteria including a visual schematic. In the third reading the same images were assessed but radiologists had access to images from two additional time points. Inter-rater reliability was assessed after each reading using kappa (κ) and percentage agreement for categorical and binary parameters and intra-class correlation coefficient (ICC) for continuous parameters. RESULTS: Parameters that were revised with more explicit definitions including the visual schematic demonstrated consistent or improved inter-rater reliability with the exception of continuous cortical rim present and cyst location in the metaphysis and mid-diaphysis. Cortical rim displayed only slight reliability throughout (κ= -0.008 to 0.16). All other categorical parameters had a percentage agreement above 0.8 or a moderate (κ= 0.41 to 0.60), substantial (κ = 0.61 to 0.80) or almost perfect inter-rater reliability (κ = 0.81 to 1.0) in at least one reading. All continuous parameters demonstrated excellent inter-rater reliability (ICC > 0.75) in at least one reading with the exception of scalloping (ICC = 0.37 to 0.70). Inter-rater reliability values did not indicate an obviously superior method of assessment between single and serial chronological readings. CONCLUSION: Explicit criteria for SBC parameters used in their assessment demonstrated improved and substantial inter-rater reliability. Inter-rater reliability did not differ between single and serial chronological readings. LEVEL OF EVIDENCE: Not Applicable.

Imaging of haemophilic arthropathy in growing joints: pitfalls in ultrasound and MRI.

The purpose of this review was to summarize the current knowledge on the utilization of magnetic resonance imaging (MRI) and ultrasound (US) for assessing arthropathy in children and adolescents with haemophilia and to recognize the limitations of each imaging modality and pitfalls in the diagnosis of soft tissue and osteochondral abnormalities. Awareness of MRI and US limitations and pitfalls in the assessment of joints in persons with haemophilia is essential for accurate diagnosis and optimal management of haemophilic arthropathy.

A systematic review of ultrasound imaging as a tool for evaluating haemophilic arthropathy in children and adults.

The purpose of this study was to semi-quantitatively assess the evidence on the value of ultrasound (US) for assessment of haemophilic arthropathy (HA) in children and adults based on the following questions: (1) Does early diagnosis of pathological findings, using available US techniques, impact the functional status of the joint? (2) Do current available US techniques have the ability to accurately detect pathological changes in target joints in haemophilic patients? (3) Does treatment (prophylaxis) improve US evidence of haemophilic arthropathy in children and adults? (4) Is there any association between various US scoring systems and other clinical/radiological constructs? Of the 6880 citations identified searching databases such as MEDLINE, Embase, CENTRAL and Web of Science, 20 articles investigating either the diagnostic accuracy of US and/or US scanning protocols and scoring systems for assessment of HA met the inclusion criteria for the study. Of these, 14 articles evaluating the diagnostic accuracy of US were assessed by two independent reviewers for reporting quality using the Standards for Reporting of Diagnostic Accuracy (STARD) tool and for methodological quality using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Using STARD, 1/14 studies (7%) was scored as of high reporting quality and 8/14 (57%), of moderate quality. Assessment with QUADAS-2 reported 2/14 (14%) studies as having high methodological quality and 6/14 (43%) as having moderate quality. There is fair evidence (Grade B) to recommend US as an accurate technique for early diagnosis of HA, to demonstrate that US scores correlate with clinical/US constructs and to prove an association between US findings and functional status of the joint. However, there is insufficient evidence (Grade I) to conclude that US-detectable findings in HA are sensitive to changes in therapy.

Pilot study on 18 F-FDG PET/CT for detection of inflammatory changes in blood-induced knee arthropathy in a rabbit model.

RATIONALE: 18 F-FDG-PET/CT has a potential role in the early detection of haemophilic arthritis, at a time when treatment may still avoid further joint degeneration. The purposes of this pilot study were to determine the ability of 18 F-FDG-PET/CT to detect inflammatory changes associated with blood-induced arthropathy in knees of a rabbit model. METHODS: Ten juvenile rabbits were imaged at baseline and weeks 5 and 17 post intraarticular autologous blood injections (ABI). Five rabbits in group 1 (G1) had ABI into the same knee joint every 2 weeks (total, eight injections). Five rabbits in group 2 (G2) had only two injections into the same knee, at weeks 5 and 17. Images were assessed visually and semi-quantitatively by measuring maximal standardized uptake values (SUVmax) and standardized uptake ratio (SUR = SUVmax in affected knee/SUVmax in non-affected knee). RESULTS: More rabbits in G1 than G2 presented with positive chronic inflammatory synovial scores at week 17. Mean iron staining scores in injected knees were greater for G1 than for G2 (P = 0.049). No increased uptake was identified in the injected knees in any of the rabbits at baseline or at week 5. At week 17, all G1 rabbits demonstrated increased uptake in their affected knees with higher mean SUVmax (1.5) than normal knees (1.0) (P < 0.02). None of the G2 rabbits showed asymmetric increased uptake. The SUR of G1 was higher at week 17 compared to baseline (P < 0.01) and week 5 (P < 0.01). The SUR at week 17 was higher for G1 than for G2 (1.13) rabbits (P < 0.01). CONCLUSION: 18 F-FDG-PET is able to detect the inflammatory changes associated with haemophilic arthropathy in this experimental model.

Correlating clinical and radiological assessment of joints in haemophilia: results of a cross sectional study.

OBJECTIVES: This study was undertaken to determine the correlation between the radiological changes in haemophilic arthropathy [X-ray, Ultrasound (US) and MRI] and clinical assessment as determined by the Hemophilia Joint Health Score (HJHS); and to document the US and MRI changes in joints that appear normal on plain X-ray and clinical evaluation. MATERIALS AND METHODS: Of 55 study joints (22 knees and 33 ankles) in 51 patients with haemophilia/von Willebrand disease, with a median age of 15 years (range: 5-17) were assessed using X-rays (Pettersson score) and clinical examination (HJHS) at two centres (Toronto, Canada; Vellore, India). MRI and ultrasonographic scoring was done through a consensus assessment by imagers at both centres using the IPSG MRI and US scores. RESULTS: The HJHS had a good correlation with the Pettersson score (rs = 0.66). Though the HJHS had moderate correlation with the osteochondral component of the MRI and US scores (rs 0.51, 0.45 respectively), its correlation with the soft tissue component was poor (rs 0.19; 0.26 respectively). Of the 18 joints with a Pettersson score of zero, 88.9% had changes that were detected clinically by the HJHS. Osteochondral abnormalities were identified in 38.9% of these joints by the MRI, while US images of the same joints were deemed abnormal in 83.3% by the current criteria. US identified haemosiderin and other soft tissue changes in all of the joints, while the same changes were noted in 94.4% of these joints on MRI. There were four joints with a HJHS of zero, all of which had soft tissue changes on MRI (score 1-7) and US (score 2-7). Osteochondral changes were detected in three of these joints by US and in 2 by MRI. There were four joints with an MRI score of 0-1 that had significant US scores (3-5) and HJHS scores (0-6). CONCLUSION: US and MRI are able to identify pathological changes in joints with normal X-ray imaging and clinical examination. However, further studies are required to be able to differentiate early abnormalities from normal. Clinical (HJHS) and radiological assessment (US/MRI) provide complimentary information and should be considered conjointly in the assessment of early joint arthropathy.

Longitudinal assessment of bone loss using quantitative ultrasound in a blood-induced arthritis rabbit model.

INTRODUCTION: Osteoporosis is common in haemophilic arthropathy. Quantitative ultrasound (QUS) can be a suitable alternative for dual-energy x-ray absorptiometry for diagnosing osteoporosis in haemophiliacs due to its lack of ionizing radiation, and ease to use. AIM: We investigated the intra- and inter-operator reliability of QUS, its responsiveness to bone growth, its ability to differentiate bone adjacent to blood-injected vs. control joints, and the effect of soft tissues on the speed of sound (SOS) QUS values in a juvenile white New Zealand rabbit model of blood-induced arthritis. METHODS: Eight of 16 rabbits were injected with autologous blood (0.1 mL kg(-1) ) 8 times over a 17-week period, the remaining eight rabbits served as controls. SOS was measured at baseline, weeks 8 and 17 in vivo and after the bones were excised on week 17. RESULTS: Intra- and inter-operator coefficients of variation for QUS data were <5% and intraclass correlation coefficients were >60% for 22/27 (81.5%) of bones assessed. The level of interval increase in SOS values from baseline to week 17 was significantly different in tibiae of injected, contralateral to injected and non-injected knee groups by anova (P = 0.01). In vivo (mean ± SD, 4147.17 ± 96.27 m s(-1) ) and postmortem (4457.85 ± 104.00 m s(-1) ) measurements on week 17 differed (P < 0.01) indicating an effect of soft tissues on SOS. CONCLUSION: In conclusion, QUS' acceptable reliability, its responsiveness to growth-related changes and its ability to discriminate injected and non-injected joints make this technique a plausible candidate as a diagnostic tool for osteoporosis in the paediatric haemophilic population if these results are confirmed upon animal-human translation.

Ultrasound and magnetic resonance imaging of healthy paediatric ankles and knees: a baseline for comparison with haemophilic joints.

The study was undertaken to document cartilage and soft tissue changes/findings in ankles and knees of normal children of different age groups to be used for comparison in the assessment of children with haemophilia. Cartilage thickness and soft tissue changes were recorded at predetermined sites of ankles/knees on both US and MRI in healthy boys in three age groups: 7-9; 10-14; and 15-18 years. To assess the validity of the ultrasound and MRI measurements, an ex vivo study was done using agar phantoms with techniques and scanners similar to those applied in vivo. Twenty (48%) knees and 22 (52%) ankles of 42 boys, were evaluated. There was a reduction in the thickness of joint cartilage with age. A difference in cartilage measurements was noted in most sites between the age groups on both US and MRI (P < 0.05 each), but such difference was not noted for joint fluid in ankles or knees (P = 0.20, P = 0.68 or P = 0.75, P = 0.63 for US, MRI, respectively). Although cartilage measurements were smaller on US than on MRI for both ankles and knees (P < 0.05 each), this observation was not recorded for fluid in knees (P = 0.02). For diminutive measurements (2 mm) mean US measurements were smaller than corresponding phantom's measurements, P = 0.02. Age-related measurements were noted for cartilage thickness on US and MRI in ankles and knees. US measurements were smaller than corresponding MRI measurements at most joint sites, which were supported by results on small-diameter phantoms.

USPIO-related T1 and T2 mapping MRI of cartilage in a rabbit model of blood-induced arthritis: a pilot study.

Ultrasmall paramagnetic iron oxide (USPIO)-enhanced MRI is promising for evaluating inflammation. The aims of this study were to investigate the effect of USPIO on cartilage T1 and T2 mapping, and to evaluate a proposed rapid vs. conventional T2 map method for imaging cartilage in a blood-induced arthritis model. Knees of nine arthritic (induction by intra-articular autologous blood injection) and six control rabbits were imaged over time (baseline, weeks 1, 5, 10) by 1.5 T MRI. All rabbits had USPIO (35-75 µmol Fe/kg)-enhanced MRI at each time point. T1 and T2 (conventional and rapid) maps and signal-to-noise ratios (SNR) were obtained pre- and post-USPIO administration. Cartilage biochemistry and histology were compared with MRI. Excellent correlations were noted between T1 map values and histologic scores at week 10 pre-USPIO (medial, r = 0.93, P = 0.0007; lateral, r = 0.87, P = 0.005) in the arthritic group, but not between T2 map and histology. Marginally and significant differences were observed between pre- and post-USPIO T2 values at weeks 5 (P = 0.06) and 10 (P = 0.02), but only with the administration of high USPIO doses in the arthritic group using the conventional method. No significant differences were noted between pre- and post-USPIO T1 values at any imaging time points. Cartilage T2 maps with short-TR and conventional protocols provided similar T2 values [(decreased trend)] (P > 0.05). Concomitant use of USPIO to T1 and T2 mapping of cartilage would not impair the identification of interval changes of T1 and T2 maps. Rapid T2 map provides similar results compared to conventional method, but its validation warrants further investigation.

A systematic review of MR imaging as a tool for evaluating haemophilic arthropathy in children.

Our purposes were to determine: (i) whether there is direct evidence that currently available MRI techniques are accurate for early diagnosis of pathological findings in haemophilic arthropathy; (ii) whether there is an MRI scoring system that best correlates with clinical/radiological constructs for evaluation of haemophilic arthropathy; (iii) whether there is an MRI scoring system that best correlates with clinical/radiological constructs for evaluation of haemophilic arthropathy. Articles were screened using MEDLINE (n = 566), EMBASE (n = 201), and the Cochrane Library (n = 1). Two independent reviewers assessed articles for inclusion under the overarching purposes of the review by using the Standards for Reporting of Diagnostic Accuracy (STARD) tool, and the quality of the studies were graded using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. The electronic literature search retrieved 777 references (after duplicates were removed). A total of 32 studies were chosen for inclusion from the results of the search and review of bibliographical references. Using the STARD tool, seven studies were of excellent quality of reporting, and using the QUADAS-2 tool, 10 studies were judged to be of adequate quality. There is 'fair' evidence to recommend MRI as an accurate test for detecting evidence of haemophilic arthropathy and the use of second or third generation MRI scales for assessing haemophilic arthropathy. However, there is no evidence that screening of early intra-articular soft tissue bleed with MRI improves the functional status of joints over time.

Magnetic resonance imaging and joint outcomes in boys with severe hemophilia A treated with tailored primary prophylaxis in Canada.

BACKGROUND/OBJECTIVES: Tailored primary prophylaxis (TPP) is a reduced-intensity treatment program for hemophiliacs with the goal of preventing arthropathy. Our primary aim was to evaluate the joint outcomes of treated subjects using magnetic resonance imaging (MRI) and physical examination as outcome measures. METHODS: Ankles, elbows and knees (index joints) of 24 subjects (median [range] age at start of therapy, 1.6 [1-2.5] years) with severe hemophilia A enrolled in the Canadian Hemophilia Primary Prophylaxis Study (CHPS) were examined by MRI at a median age of 8.8 years (range 6.2-11.5 years). Subjects were treated with TPP using a recombinant factor VIII concentrate, starting once weekly and escalating in frequency and dose according to frequency of bleeding. RESULTS: Osteochondral changes (cartilage loss/subchondral bone damage) were detected in 9% (13/140) of the index joints and 50% (12/24) of study subjects. Osteochondral changes were restricted to joints with a history of clinically reported joint bleeding. Soft tissue changes were detected in 31% (20/65) of index joints with no history of clinically reported bleeding (ankles 75% (12/16); elbows 19% (6/32); and knees 12% (2/17)). In these apparently 'bleed free' index joints hemosiderin deposition was detected by MRI in 26% (17/65) of joints (ankles 63% (10/16); elbows 16% (5/32), and knees 12% (2/17)). CONCLUSION: TPP did not completely avoid the development of MRI-detected structural joint changes in hemophilic boys in this prospective study. A longer period of follow-up is required for assessment of the longitudinal course of these early changes in hemophilic arthropathy, detected using a sensitive imaging technique (MRI).

An MRI scale for assessment of haemophilic arthropathy from the International Prophylaxis Study Group.

Evaluation of prophylactic treatment of haemophilia requires sensitive methods. To design and test a new magnetic resonance imaging (MRI) scale for haemophilic arthropathy, two scales of a combined MRI scoring scheme were merged into a single scale which includes soft tissue and osteochondral subscores. Sixty-one joint MRI's of 46 patients with haemophilia were evaluated by four radiologists using the new and older scales. Forty-six of the joints were evaluated using two X-ray scales. For all MRI scores, interreader agreement and correlations with X-ray scores and lifetime number of haemarthroses were analysed. The interreader agreement intraclass correlation coefficient was 0.82, 0.89 and 0.88 for the soft tissue and osteochondral subscores and the total score, as evaluated according to the new MRI scale, compared to 0.80 and 0.89 as for the older scales. The total score and osteochondral subscore according to the new scale, as well as scores according to the older scales were correlated (P < 0.01) with number of haemarthroses (Spearman correlation 0.35-0.68) and with the X-ray scores (Spearman correlation 0.40-0.76), but no correlation (P > 0.05) was found between the soft tissue subscore of the new MRI scale and the X-ray scores. The new MRI scale is simpler to apply than the older and has similar reader reliability and correlation with lifetime number of haemarthroses, and by separating soft tissue and osteochondral changes it gives additional information. The new scale is useful for analyses of early and moderate stages of arthropathy, and may help to evaluate prophylactic haemophilia treatment.

State-of-the-art imaging techniques for the evaluation of haemophilic arthropathy: present and future.

SUMMARY: In spite of the fact that the diagnosis of haemophilia is essentially clinical and laboratory-based, imaging has become an important tool for the evaluation of complications, diagnostic confirmation and/or complementation and therapeutic follow-up in haemophilic arthropathy. Radiography remains the workforce horse in the diagnosis and follow-up of haemophilic arthropathy. The radiographical findings in arthropathy follow an expected sequence of events and are overall similar in different joints. Magnetic resonance imaging (MRI) has advantages over radiography based on its capability of visualizing soft tissue and cartilage changes in haemophilic joints. The recent development and standardization of MRI scoring systems for measuring soft tissue and cartilage abnormalities may enable the comparison of pathological joint findings in clinical trials conducted at different institutions across the world. The implementation of high-frequency transducers and colour/power Doppler capabilities has provided new insights for clinical applications of ultrasonography (US) in haemophilic arthropathy. In spite of the imaging modality's technical challenges such as operator-dependency, US has advantages over MRI. One of these advantages is its ability of differentiating synovium hypertrophy and hemosiderin deposition, which is not possible with MRI given the presence of susceptibility artefacts from extracellular hemosiderin on gradient-echo MR images. In addition to the aforementioned conventional imaging modalities, novel imaging techniques (blood oxygen level dependent, ultrasmall superparamagnetic iron-oxide contrast-enhanced, and T1 and T2 mapping MRI, ultrasound biomicroscopy, microbubble contrast-enhanced US and positron emission tomography, among others) hold promise for early assessment of haemophilic arthropathy in the future upon completion of their clinical validation.

Cost-effectiveness analysis of different imaging strategies for diagnosis of haemophilic arthropathy.

SUMMARY: Physiotherapy and radiography of the joints are standard diagnostic strategies for assessment of haemophilic arthropathy. The use of ultrasonography as an adjunct tool for early diagnosis of haemophilic arthropathy may optimize factor replacement therapy. The objective of this study was to compare costs and effectiveness of physiotherapy, radiography and ultrasonography (intervention strategy, IS) with physiotherapy and radiography alone (standard care strategy, SCS) for diagnosing soft tissue and osteocartilaginous changes in haemophilic joints. We retrospectively compared costs and effectiveness of IS vs. SCS in knees, ankles and elbows of 31 children (age range, 4-17 years) with haemophilia A (n = 30) or B (n = 1) (IS, n = 11; SS, N = 20). Direct health care costs were measured from the provincial health care perspective. Effectiveness was measured by false-negative (FN) rates in each study arm by comparing presence or absence of abnormalities of physiotherapy and imaging exams to the reference standard measure (MRI). In scenario 1, all diagnostic tests matched with MRI. In scenario 2, at least one diagnostic test matched with MRI. The IS was more costly [incremental cost/100 patients, Canadian (CND) $4987] and more effective (incremental effectiveness, FNs/100 patients for scenario 1, -4.09, and for scenario 2, -41) for both scenarios. The incremental cost-effectiveness ratios for scenario 1 and for scenario 2 were CND$1166 and CDN$116 per FN result averted per 100 patients, respectively. In conclusion, in the short-term, the incorporation of ultrasonography in a test set for diagnosis of haemophilic arthropathy substantially improved the diagnostic performance of this test set, however at an increased cost.

New images in haemophilia.

New imaging techniques are valuable for the care of patients with haemophilia. On angiography it is shown that some bleedings in severely damaged joints or after implantation of prostheses are arterial. Effect of clotting factor is often poor. Selective catherization with embolization of the bleeding artery stops the bleed and is clinically effective. From 31 patients with severe haemophilia A or B, 62 knee radiographs were scored according to the Pettersson-scoring system as well as with Knee Digital Image Analysis (KIDA). Using KIDA, good correlation was found for osteoporosis, irregular subchondral surface, narrowing of the joint space, deformity and incongruence. For each of the parameters within one point in the Pettersson score a large variation existed in KIDA grading. MRI is accurate for diagnosis of soft and osteochondral tissue. Nevertheless, it is costly and not very accessible. The use of parallel imaging is more feasible for assessment of multiple joints within a relatively short period of time. Although ultrasonography also holds the potential for being an adjunct to MRI it has the disadvantage that it is operator-dependent. In a cohort of 124 chronically HCV infected haemophilia patients transient elastography was performed to measure liver stiffness. 57 (46%) had no or mild fibrosis, 18 (14.5%) moderate fibrosis and 49 severe or cirrhotic fibrosis. Transient elastography is safe and helpful to refer patients to antiviral therapy.

Reliability and construct validity of the compatible MRI scoring system for evaluation of elbows in haemophilic children.

We assessed the reliability and construct validity of the Compatible MRI scale for evaluation of elbows, and compared the diagnostic performance of MRI and radiographs for assessment of these joints. Twenty-nine MR examinations of elbows from 27 boys with haemophilia A and B [age range, 5-17 years (mean, 11.5)] were independently read by four blinded radiologists on two occasions. Three centres participated in the study: (Toronto, n = 24 examinations; Atlanta, n = 3; Cuiaba, n = 2). The number of previous joint bleeds and severity of haemophilia were reference standard measures. The inter-reader reliability of MRI scores was substantial (ICC = 0.73) for the additive (A)-scale and excellent (ICC = 0.83) for the progressive (P)-scale. The intrareader reliability was excellent for both P-scores (ICC = 0.91) and A-scores (ICC = 0.93). The total P- and A-scores correlated poorly (r = 0.36) or moderately (r = 0.54), but positively, with clinical-laboratory measurements. The total MRI scores demonstrated high accuracy for discrimination of presence or absence of arthropathy [P-scale, area-under-the-curve (AUC) = 0.94 +/- 0.05; A-scale, AUC = 0.89 +/- 0.06], as did the soft tissue scores of both scales (P-scale, AUC = 0.90 +/- 0.06; A-scale, AUC = 0.86 +/- 0.06). Areas-under-the-curve used to discriminate severe disease demonstrated high accuracy for both P-MRI scores (AUC = 0.83 +/- 0.09) and A-MRI scores (AUC = 0.87 +/- 0.09), but non-diagnostic ability to discriminate mild disease. Similar results were noted for radiographic scales. In conclusion, both MRI scales demonstrated substantial to excellent reliability and accuracy for discrimination of presence/absence of arthropathy, and severe/non-severe disease, but poor to moderate convergent validity for total scores and non-diagnostic discriminant validity for mild/non-mild disease. Compared with radiographic scores, MRI scales did not perform better for discrimination of severity of arthropathy.