Computer-based automated analysis of X-ray and thermal imaging of knee region in evaluation of rheumatoid arthritis

Medical imaging in rheumatoid arthritis: A review on deep learning approach

Arthritis is a musculoskeletal disorder. Millions of people have arthritis, making it one of the most common joint disorders. Osteoarthritis (OA) and rheumatoid arthritis (RA) are the most common types of arthritis among the many different types available. Pain, stiffness, and inflammation are among the early signs of arthritis, which can progress to severe immobility at a later stage if left untreated. Although arthritis cannot be cured at any point in time, it can be managed if diagnosed and treated correctly. Clinical diagnostic and medical imaging methods are currently used to evaluate OA and RA, both debilitating conditions. This review is focused on deep learning approaches used by taking medical imaging (X-rays and magnetic resonance imaging) as input for the detection of RA.

Receiver operating characteristic analysis using a novel combined thermal and ultrasound imaging for assessment of disease activity in rheumatoid arthritis

We aim to determine whether combined thermal and ultrasound (CTUS) imaging can identify rheumatoid arthritis (RA) patients with at least moderate disease activity (DAS28 > 3.2). Temperature differences of maximum (T_max), average (T_avg) and minimum (T_min) temperatures from a control temperature at 22 joints (bilateral hands) were summed up to derive the respective MAX, AVG and MIN per patient. MAX (PD), AVG (PD) and MIN (PD) are CTUS results derived by multiplying MAX, AVG and MIN by a factor of 2 when a patient's total ultrasound power Doppler (PD) joint inflammation score > median score, which otherwise remained unchanged. Receiver operating characteristic (ROC) analysis was used to determine whether CTUS imaging can identify patients with DAS28 > 3.2. In this cross-sectional study, 814 joints were imaged among 37 RA patients (mean disease duration, 31 months). CTUS (but not single modality) imaging parameters were all significantly greater comparing patients with DAS28 > 3.2 versus those with DAS28 ≤ 3.2 (all P < 0.01). Area under the ROC curves (AUCs) using cut-off levels of ≥ 94.5, ≥ 64.6 and ≥ 42.3 in identifying patients with DAS28 > 3.2 were 0.73 , 0.76 and 0.76 for MAX (PD), AVG (PD) and MIN (PD), respectively (with sensitivity ranging from 58 to 61% and specificity all 100%). The use of CTUS in detecting a greater severity of joint inflammation among patients with at least moderate disease activity (DAS28 > 3.2) appears promising and will require further validation in independent RA cohorts.

Infrared Thermography for the Evaluation of Inflammatory and Degenerative Joint Diseases: A Systematic Review

OBJECTIVE

Inflammation plays a central role in the pathophysiology of rheumatic diseases as well as in osteoarthritis. Temperature, which can be quantified using infrared thermography, provides information about the inflammatory component of joint diseases. This systematic review aims at assessing infrared thermography potential and limitations in these pathologies.

DESIGN

A systematic review was performed on 3 major databases: PubMed, Cochrane library, and Web of Science, on clinical reports of any level of evidence in English language, published from 1990 to May 2021, with infrared thermography used for diagnosis of osteoarthritis and rheumatic diseases, monitoring disease progression, or response to treatment. Relevant data were extracted, collected in a database, and analyzed for the purpose of this systematic review.

RESULTS

Of 718 screened articles 32 were found to be eligible for inclusion, for a total of 2094 patients. Nine studies reported the application to osteoarthritis, 21 to rheumatic diseases, 2 on both. The publication trend showed an increasing interest in the last decade. Seven studies investigated the correlation of temperature changes with osteoarthritis, 16 with rheumatic diseases, and 2 with both, whereas 2 focused on the pre-post evaluation to investigate treatment results in patients with osteoarthritis and 5 in patients with rheumatic diseases. A correlation was shown between thermal findings and disease presence and stage, as well as the clinical assessment of disease activity and response to treatment, supporting infrared thermography role in the study and management of rheumatic diseases and osteoarthritis.

CONCLUSIONS

The systematic literature review showed an increasing interest in this technology, with several applications in different joints affected by inflammatory and degenerative pathologies. Infrared thermography proved to be a simple, accurate, noninvasive, and radiation-free method, which could be used in addition to the currently available tools for screening, diagnosis, monitoring of disease progression, and response to medical treatment.

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.

Thermal and Visual Imaging to Assist with Juvenile Idiopathic Arthritis Examination of the Knees

Juvenile idiopathic arthritis (JIA) causes inflammation of the joints, and it is frequently associated with their pain and stiffness. Its timely diagnosis is important to avoid its progressive damage to the bones and cartilage. Increases in the joint’s temperature and redness could be indicators of active JIA, hence their accurate quantification could assist with diagnosis. Thermal and visual images of the knees in 20 JIA participants (age: mean = 11.2 years, standard deviation = 2.3 years) were studied. The median temperature of knees with active inflammation was 3.198% higher than that of inactive knees. This difference, examined by a Wilcoxon signed-rank test, was statistically significant (p = 0.0078). In six out of the eight participants who had one active inflamed knee, thermal imaging identified the corresponding knee as warmer. In 16 out of 20 participants, the knee identified as warmer by thermal imaging was also identified as having a greater colour change by visual imaging as compared to their respective reference regions. The devised methods could accurately quantify the colour and temperature of the knees. It was concluded that thermal and visual imaging methods can be valuable in examining JIA. Further studies involving a larger number of participants and more detailed explorations would be needed prior to clinical application.

Estimating Respiratory Rate in Post-Anesthesia Care Unit Patients Using Infrared Thermography: An Observational Study

The post-anesthesia care unit (PACU) is the central hub for recovery after surgery, especially when the surgery is performed under general anesthesia. Aside from clinical aspects, respiratory impairment is one of the major causes of morbidity and affected recovery in the PACU and should therefore be monitored. In previous studies, infrared thermography was applied to assess the breathing rate (BR) of healthy volunteers. Here, the transferability of published methods for postoperative patients in the PACU was examined. Video recordings of 28 patients were acquired using a long-wave infrared camera, and analyzed offline. For validation purposes, BRs derived from body surface electrocardiography were measured simultaneously. In general, a close agreement between the two techniques (r = 0.607, p = 0.002 upon arrival, and r = 0.849, p < 0.001 upon discharge from the PACU) was obtained. In conclusion, the algorithm was demonstrated to be feasible and reliable under these challenging conditions.