Thermography and colour Doppler ultrasound: a potential complementary diagnostic tool in evaluation of rheumatoid arthritis in the knee region

The aim and objectives of this study were as follows: (i) to perform automated segmentation of knee thermal image using the regional isotherm-based segmentation (RIBS) algorithm and segmentation of ultrasound image using the image J software; (ii) to implement the RIBS algorithm using computer-aided diagnostic (CAD) tools for classification of rheumatoid arthritis (RA) patients and normal subjects based on feature extraction values; and (iii) to correlate the extracted thermal imaging features and colour Doppler ultrasound (CDUS) features in the knee region with the biochemical parameters in RA patients. Thermal image analysis based on skin temperature measurement and thermal image segmentation was performed using the RIBS algorithm in the knee region of RA patients and controls. There was an increase in the average skin temperature of 5.94% observed in RA patients compared to normal. CDUS parameters such as perfusion, effusion and colour fraction for the RA patients were found to be 1.2 ± 0.5, 1.8 ± 0.2 and 0.052 ± 0.002, respectively. CDUS measurements were performed and analysed using the image J software. Biochemical parameters such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) showed significant positive correlation with the thermal imaging parameters. The CDUS parameters such as effusion, perfusion and colour fraction correlated significantly with the clinical and functional assessment score. According to the results of this study, both infrared (IR) thermal imaging and CDUS offer better diagnostic potential in detecting early-stage RA. Therefore, the developed CAD model using thermal imaging could be used as a pre-screening tool to diagnose RA in the knee region.

Power Color Doppler and Spectral Doppler Ultrasonography to Evaluate Response to Intra-articular Steroid Injection in Knee Joints in Juvenile Idiopathic Arthritis

OBJECTIVE

To evaluate the role of ultrasonographic indices (Color Fraction and Resistive Index) in assessing the effect of intra-articular steroid (IAS) injection on synovial inflammation in knee joints of Juvenile Idiopathic Arthritis (JIA) patients and to determine the correlation between these ultrasonographic indices and clinical and laboratory parameters in JIA patients after IAS.

METHODS

Twenty seven patients of JIA and equal number of age and sex matched healthy controls were enrolled. Thirty six knee joints were injected with IAS. Duration of morning stiffness, swelling score, tenderness score, range of motion, visual analogue scale for pain, Physician global assessment of disease activity, Patient/Parent assessment of general well being, Juvenile Arthritis Disease Activity Score, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), synovial thickness, synovial effusion, Color fraction (CF) and Resistive index (RI) were measured at base line and at one and two months of follow-up.

RESULTS

At baseline, a significant difference was found in ESR, CRP, CF and RI values between cases and controls. A significant decrease in various clinical, core set variables and ultrasonographic parameters was observed at each follow-up. Synovial thickness, synovial effusion and CF decreased by 51.78%, 64.67% and 49.35% respectively and range of motion and RI increased by 166% and 31.94% respectively at second follow-up. Both CF and RI showed a significant correlation with active joint count. Both CF and RI had a high inter and intra-class correlation.

CONCLUSIONS

Power Color Doppler and Spectral Doppler ultrasonographic indices (CF and RI) may have a role in assessment of the response to IAS injection of inflamed knee joints.

Ultrasound imaging of synovial inflammation in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is the most common rheumatic entity of childhood. The hallmark feature of all subtypes is joint inflammation. Imaging is used to evaluate the extent and severity of inflammation, degree of joint damage and response to treatment, which in turn impacts patient management. Ultrasound has become a useful adjunct to clinical examination because it shows promise in evaluating clinical and subclinical inflammation (synovitis, enthesitis) as well as cartilage and bone erosive changes. However more collaborative research is needed to help define the normal appearance of the growing skeleton, clarify the significance of subclinical findings and develop useful definitions, imaging protocols and scoring systems of disease.