Infrared thermal imaging for bone fracture identification and monitoring of fracture healing: A review of the latest developments

Infrared thermography (IRT) is a non-destructive imaging technology which detects thermal energy emitted from objects and converts it into numeric and visual data. IRT has been receiving increasing interest by clinicians as a non-invasive and safe tool for medical diagnosis and monitoring. Studies have reported the potential of IRT for physiological measurements, medical diagnosis and monitoring. In this paper, developments in the applications of IRT for bone fracture identification and the monitoring of fracture healing are reviewed. A significant proportion of x-rays taken to diagnose bone fracture are negative, i.e. reveal that there is no underlying fracture. IRT may have potential as a screening tool to filter out these negative cases where the injury has not resulted in fracture. Exclusion of cases without an underlying fracture would reduce the cost and exposure to harmful radiation associated with unnecessary x-ray imaging. In infants and young children, who may not be able to accurately report the site of injury, IRT may assist in locating possible injury sites, thus facilitating more timely treatment. This feature could also be valuable in child abuse cases with possible bone fracture. Some fractures, such as toddlers fracture, may not be visible on an initial x-ray examination and repeat x-ray imaging is required around two weeks later to confirm diagnosis. IRT may be able to assist clinicians in the initial assessment of such fractures, enabling a more timely diagnosis

Using thermal imaging to measure changes in breast cancer-related lymphoedema during reflexology

Background Reflexology lymph drainage (RLD) for breast cancer related lymphoedema (BCRL) may have a positive impact on arm swelling and pain. Thermal imaging is a means of tracking temperature change by visual images. Aims To explore the use of thermal imaging in treatment for BCRL. Method The swollen arms of two participants with BCRL were photographed using a thermal imaging camera during a single RLD treatment. Limb Volume Circumferential Measurement (LVCM) of both arms was taken before, after and the next day. The images were examined for visual changes, and temperature data were extracted. Findings Images showed differences in temperature within the affected hand and arm over 45 minutes. LVCM data indicated a loss of limb volume in the affected arm in both cases, which continued to decrease over 24 hours. Conclusion Thermal imaging may be useful in tracking temperature change during treatment for BCRL

Thermographic Control of Pediatric Dental Patients During the SARS-CoV-2 Pandemics Using Smartphones

Objective: To evaluate the reliability of infrared (IR) thermal camera connected to smartphones, already used in medicine for diagnostic purposes, as an easy tool for access screening to pediatric dentistry services. Material and Methods: After the preventive telephone triage, thirty orthodontic patients (7-13 years) underwent temperature measurement in the office with two no-contact IR devices: forehead digital thermometer and thermal-camera connected to a smartphone (reference areas: forehead, inner canthi, ears). Measurements were compared and differences were statistically investigated with T student’s test (p<0.01). Results: Forehead digital thermometer temperatures were superimposable to those recorded in ear areas and inner canthi with the thermal camera connected to a smartphone. Differences were not statistically significant even in comparison between the sexes. Forehead temperature values detected with a thermal camera are lower than those detected with a digital forehead thermometer. Conclusion: Thermal camera on a smartphone could be reliable in measuring body temperature. Mobile thermographic values of ears and inner canthi areas can be used as an alternative to forehead digital thermometer measurements. Further applications in pediatric dentistry of thermography on smartphones should be examined

Infrared Thermal Imaging to Detect Inflammatory Intra-Abdominal Pathology in Infants

A thermal imaging method to detect inflammatory intra-abdominal pathology in infants is proposed and evaluated through a clinical trial. Nine surgical infants, mean chronological age 58 days old (range: 21-83 days), mean weight 2.65 kg (range: 2.45-3.15 kg) with abdominal pathologies were included in the analysis. Infrared thermal image processing consisted of selecting the surgical region of interest where the area of abdominal inflammation was most likely to be, and an abdominal reference region on the same infant, with the aid of clustering segmentation. Skewness was found to be the most sensitive variable to significantly differentiate between the surgical region and reference region (p = 0.022). Multilinear regression analysis indicated that the relationship between the temperature difference signified by skewness and the patients' demographic information (age at time of imaging, gestational age at birth, weight at the time of imaging, birthweight, last stool prior to imaging and last oral intake prior to imaging) was not significant. The study indicated that inflammatory regions, such as those found in infants following surgery, would have a significantly different temperature distribution than the surrounding skin. The method differentiated between an inflammatory and non-inflammatory region on the abdomen

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

Infrared thermal imaging as a screening tool for paediatric wrist fractures

Wrist injuries are common in paediatric trauma, however only half of children evaluated with an x-ray for possible fractures will have one. Thermal imaging offers a possible non-ionising method of screening for fractures and thus reducing negative x-ray rates. 105 children attending the Emergency Department for wrist injuries were recruited. Two 30s thermal videos were recorded from injured and uninjured wrists – in flat and 45o elevated positions. A region of interest (ROI) was defined on each wrist. Cases in which the ROI was covered or had ice applied, were excluded, leaving 40 patients for analysis. Comparisons of ROI included (i) injured and uninjured wrists - flat and elevated positions; (ii) as in (i) with a reference region on the proximal forearm subtracted; (iii) injured wrist ROI - flat and elevated positions. Fractures and sprains increased the mean skin surface temperature by 1.519% (p=0.008) and 0.971% (p=0.055) respectively compared with the uninjured wrist. The mean temperature difference between flat and elevated positions for fractures was 0.268% and -0.1291% for sprains. This difference was statistically significant for fracture (p=0.004) but not sprain (p=0.500). The temperature differences recorded by thermal imaging between fractured and sprained wrists may assist in differentiation of these injuries

Development of a high-resolution infrared thermographic imaging method as a diagnostic tool for acute undifferentiated limp in young children (Abstract only)

Objectives & Background Acute limp is a common presenting complaint in the paediatric emergency department. There are a number of possible causes of acute limp, ranging from the minor, such as traumatic injury, to more severe conditions, such as infection or malignancy. In young children, these causes are not always easily distinguished, even with the use of radiological imaging and laboratory investigations. With this pilot study, we aimed to develop an infrared thermographic imaging technique for use as a diagnostic aid in the diagnosis and monitoring of acute undifferentiated limp in young children. Therefore, the objectives of this study were to critically evaluate the effectiveness of thermal imaging in this context, whilst developing an appropriate protocol for an emergency environment. Methods Following NHS ethics approval, 30 children were recruited from the Sheffield Children’s Hospital ED. The participants were divided into groups based on diagnosis. Using an infrared camera, the lower limbs of the participants were imaged to record the skin surface temperature of both the affected side and unaffected side. Using predefined Regions of Interest (locations of thermographic measurement on the leg), any temperature difference between the two legs of each subject was recorded and the ability to isolate the specific region affected by injury was assessed. Results In all Regions of Interest assessed, the median temperature reading for the affected side was higher than that of the unaffected side. The ability of infrared thermography to isolate the specific region affected was evident on an individual basis, with particular case studies showing promise. The small sample size recruited for each group meant that tests of significant difference need to be interpreted in this context and further research is required to form clinically meaningful conclusions. Conclusion This pilot study has highlighted a number of potential avenues for future research into the use of thermographic imaging in an emergency setting. Repeating a similar study with a larger sample size will allow more credence to be given to the tests of significant difference. This study indicated that thermal imaging shows promise as an additional tool in the diagnosis and monitoring of acute undifferentiated limp in young children

Thermal and Visual Imaging and Accelerometry Developments to Assist with Arthritis Diagnosis

Juvenile Idiopathic Arthritis (JIA) is a disease that causes pain and inflammation in the joints of children. Its early diagnosis is important to avoid damage to the joints. Joint warmth, redness and movement restriction may be indicators of active arthritis hence accurate objective means to measure temperature, colour and range of movement (ROM) at the joint may assist diagnosis. In this study, three techniques with a potential to assist clinicians in diagnosing JIA were developed. These were based on high-resolution thermal imaging (HRTI), visual imaging and accelerometry. A detailed correlation analysis was performed between the developed methods and the consultant's clinical assessment of JIA diagnosis. Twenty-two patients (age: mean=10.6 years, SD = 2 years) with JIA diagnosis were recruited. 18 participated in the thermal/visual imaging study only, 2 in the accelerometry study only and 2 in both thermal/visual imaging and accelerometry studies. Thermal and visual images of the front and back of the knees and ankles of 20 patients were studied. All ethical approvals from Sheffield Hallam University and the National Health Service (NHS) were duly obtained before commencing the study. The thermal/visual imaging study involved developing image processing techniques to accurately identify and segment the regions of interest (ROIs). A tracking algorithm to accurately locate the ROIs was also implemented. An accelerometry system that is capable of recording movements from 4 channels was developed and its signals were processed by frequency spectrum analysis, short-time Fourier transform and wavelet packet analysis. The thermal imaging results showed a combined 71% correlation (for the front of knees and ankles) with clinical assessment. It may be possible that patients whom their arthritic joint was cooler than their healthy joints may have relied on their healthy leg more extensively for mobility (due to the pain on the arthritic leg) thus increasing its joints temperature. It was also found that JIA may affect the skin colour with a combined 42% correlation between the knees and ankles. The accelerometry results showed a 75% correlation with clinical assessment. The study for the first time brought together the three techniques of thermal imaging, visual imaging and accelerometry to assist with JIA diagnosis. The study demonstrated that the developed techniques have potential in assisting clinicians with JIA diagnosis. Improvements in timely diagnosis allow more effective treatment and can reduce the likelihood of joint damage in rheumatoid arthritis

Thermal imaging developments for respiratory airflow measurement to diagnose apnoea

Sleep-disordered breathing is a sleep disorder that manifests itself as intermittent pauses (apnoeas) in breathing during sleep. The condition disturbs the sleep and can results in a variety of health problems. Its diagnosis is complex and involves multiple sensors attached to the person to measure electroencephalogram (EEG), electrocardiogram (ECG), blood oxygen saturation (pulse oximetry, S