Sonographic assessment of cartilage damage at the metacarpal head in rheumatoid arthritis: qualitative versus quantitative methods.

OBJECTIVE: To test the validity of the OMERACT semi-quantitative score by comparing with a quantitative method in the US assessment of hyaline cartilage at the metacarpal head (MH) in patients with RA and healthy controls (HCs). METHODS: The hyaline cartilage from the second to fifth MHs of both hands was scanned. Hyaline cartilage was scored semi-quantitatively and quantitatively by measuring cartilage thickness and comparing with reference values. In RA patients, radiographic joint space narrowing (JSN) was scored on the same joints using the Simple Erosion Narrowing Score (SENS). RESULTS: A total of 408 MHs in 51 RA patients and 320 MHs in 40 HSs were evaluated. The OMERACT semi-quantitative score was quicker to perform than the quantitative method [6.0 min (s.d. 0.5) vs 8.0 (1.5); P < 0.01]. A significant correlation between the US scores (R = 0.68) and between the US scores and the JSN-SENS (R = 0.61 and R = 0.63 for the semi-quantitative and quantitative method, respectively) was found. The frequency of cartilage abnormalities was similar between the two US methods in RA patients (58.8% and 51.0% of RA patients for the semi-quantitative and quantitative method, respectively; P = 0.46), while the former revealed more abnormalities in HCs (27.5% and 7.5% of HCs; P = 0.02). CONCLUSION: The higher feasibility of the OMERACT semi-quantitative score suggests its use as a first-choice method in the evaluation of cartilage damage. However, despite its limits, the quantitative assessment of HCs, providing patient-tailored information with age- and sex-corrected cut-off values, may represent a valid supplement for optimizing the evaluation of cartilage damage in selected cases.

Reliability assessment of ultrasound muscle echogenicity in patients with rheumatic diseases: Results of a multicenter international web-based study.

Objectives: To investigate the inter/intra-reliability of ultrasound (US) muscle echogenicity in patients with rheumatic diseases. Methods: Forty-two rheumatologists and 2 radiologists from 13 countries were asked to assess US muscle echogenicity of quadriceps muscle in 80 static images and 20 clips from 64 patients with different rheumatic diseases and 8 healthy subjects. Two visual scales were evaluated, a visual semi-quantitative scale (0-3) and a continuous quantitative measurement ("VAS echogenicity," 0-100). The same assessment was repeated to calculate intra-observer reliability. US muscle echogenicity was also calculated by an independent research assistant using a software for the analysis of scientific images (ImageJ). Inter and intra reliabilities were assessed by means of prevalence-adjusted bias-adjusted Kappa (PABAK), intraclass correlation coefficient (ICC) and correlations through Kendall's Tau and Pearson's Rho coefficients. Results: The semi-quantitative scale showed a moderate inter-reliability [PABAK = 0.58 (0.57-0.59)] and a substantial intra-reliability [PABAK = 0.71 (0.68-0.73)]. The lowest inter and intra-reliability results were obtained for the intermediate grades (i.e., grade 1 and 2) of the semi-quantitative scale. "VAS echogenicity" showed a high reliability both in the inter-observer [ICC = 0.80 (0.75-0.85)] and intra-observer [ICC = 0.88 (0.88-0.89)] evaluations. A substantial association was found between the participants assessment of the semi-quantitative scale and "VAS echogenicity" [ICC = 0.52 (0.50-0.54)]. The correlation between these two visual scales and ImageJ analysis was high (tau = 0.76 and rho = 0.89, respectively). Conclusion: The results of this large, multicenter study highlighted the overall good inter and intra-reliability of the US assessment of muscle echogenicity in patients with different rheumatic diseases.

Sonographic assessment of calcium pyrophosphate deposition disease at wrist. A focus on the dorsal scapho-lunate ligament.

OBJECTIVES: To investigate the diagnostic accuracy of ultrasound and conventional radiography in the evaluation of calcium pyrophosphate crystal deposits at wrist level. METHODS: Consecutive patients with a "definite" diagnosis of calcium pyrophosphate deposition disease and disease-controls were prospectively included in this cross-sectional single-centre study. Scapho-lunate ligament, triangular fibrocartilage complex, and volar recess of the radio-lunate joint were explored using ultrasound, conventional radiography and computed tomography. RESULTS: Sixty one patients and 39 disease controls were enrolled. Two-hundred wrists were evaluated using both conventional radiography and ultrasound and 26 using computed tomography. Ultrasound findings indicative of crystal deposits were found in at least one wrist in 95.1% of patients and in 15.4% of controls (P<0.001). Scapho-lunate ligament calcifications were reported in 83.6% of patients and in 5.1% of controls (P<0.001). On conventional radiography, calcifications were found in at least one wrist in 72.1% of patients and in 0% of controls (P<0.001). Using the Ryan-McCarty criteria as a gold standard, sensitivity, specificity and diagnostic accuracy were 0.72 (0.59-0.83), 1.0 (0.91-1.0) and 0.83 (0.74-0.90) for conventional radiography and 0.95 (0.86-0.99), 0.85 (0.69-0.94) and 0.91 (0.84-0.96) for ultrasound. The agreement between ultrasound and computed tomography was substantial when assessing triangular fibrocartilage complex (kappa=0.70; 0.43-0.97) and scapho-lunate ligament (kappa=0.69; 0.41-0.97), and moderate for radio-lunate joint (kappa=0.46; 0.12-0.80). CONCLUSIONS: This study supports the diagnostic accuracy of ultrasound in evaluating wrist involvement in calcium pyrophosphate deposition disease. The inclusion of the scapho-lunate ligament in a disease-oriented scanning protocol could improve the diagnostic performance of ultrasound.