Automated processing of thermal imaging to detect COVID-19 and microvascular dysfunction

Background

Coronavirus disease 2019 (COVID-19) is associated with microvascular dysfunction. Non-invasive thermal imaging can hypothetically detect changes in perfusion, inflammation and vascular injury. We sought to develop a new point-of-care, non-contact thermal imaging tool to detect COVID-19 by microvascular dysfunction, based on image processing algorithms and machine learning analysis.

Materials and methods

We captured thermal images of the back of 101 individuals, with (n=62) and without (n=39) COVID-19, using a portable thermal camera that connects directly to smartphones. We developed new image processing algorithms that automatically extract multiple texture and shape features of the thermal images (Figure 1A). We then evaluated the ability of our thermal features to detect COVID-19 and systemic changes of heat distribution associated with microvascular disease. We also assessed correlations between thermal imaging to conventional biomarkers and chest X-ray (CXR).

Results

Our novel image processing algorithms achieved up to 92% sensitivity in detecting COVID-19 with an area under the curve of 0.85 (95% CI: 0.78, 0.93; p<0.01). Systemic alterations in blood flow associated with vascular disease were observed across the entire back. Thermal imaging scores were inversely correlated with clinical variables associated with COVID-19 disease progression, including blood oxygen saturation, C- reactive protein, and D-dimer. The thermal imaging findings were not correlated with the results of CXR.

Conclusions

We show, for the first time, that a hand-held thermal imaging device can be used to detect COVID-19. Non-invasive thermal imaging could be used to screen for COVID-19 in out-of-hospital settings, especially in low-income regions with limited imaging resources. Moreover, thermal imaging might detect micro-angiopathies and endothelial dysfunction in patients with COVID-19 and could possibly improve risk stratification of infected individuals (Figure 1B).

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): 1. The Israel Innovation Authority2. The Nicholas and Elizabeth Slezak Super Center for Cardiac Research and Biomedical Engineering at Tel Aviv University Figure 1. A. Representative steps of our thermal image processing algorithms. B. A schematic illustration of the research design and potential impact.

Development and validation of a machine-learning model for prediction of shoulder dystocia

OBJECTIVES

To develop a machine-learning (ML) model for prediction of shoulder dystocia (ShD) and to externally validate the model's predictive accuracy and potential clinical efficacy in optimizing the use of Cesarean delivery in the context of suspected macrosomia.

METHODS

We used electronic health records (EHR) from the Sheba Medical Center in Israel to develop the model (derivation cohort) and EHR from the University of California San Francisco Medical Center to validate the model's accuracy and clinical efficacy (validation cohort). Subsequent to application of inclusion and exclusion criteria, the derivation cohort included 686 singleton vaginal deliveries, of which 131 were complicated by ShD, and the validation cohort included 2584 deliveries, of which 31 were complicated by ShD. For each of these deliveries, we collected maternal and neonatal delivery outcomes coupled with maternal demographics, obstetric clinical data and sonographic fetal biometry. Biometric measurements and their derived estimated fetal weight were adjusted (aEFW) according to gestational age at delivery. A ML pipeline was utilized to develop the model.

RESULTS

In the derivation cohort, the ML model provided significantly better prediction than did the current clinical paradigm based on fetal weight and maternal diabetes: using nested cross-validation, the area under the receiver-operating-characteristics curve (AUC) of the model was 0.793 ± 0.041, outperforming aEFW combined with diabetes (AUC = 0.745 ± 0.044, P = 1e^-16 ). The following risk modifiers had a positive beta that was > 0.02, i.e. they increased the risk of ShD: aEFW (beta = 0.164), pregestational diabetes (beta = 0.047), prior ShD (beta = 0.04), female fetal sex (beta = 0.04) and adjusted abdominal circumference (beta = 0.03). The following risk modifiers had a negative beta that was < -0.02, i.e. they were protective of ShD: adjusted biparietal diameter (beta = -0.08) and maternal height (beta = -0.03). In the validation cohort, the model outperformed aEFW combined with diabetes (AUC = 0.866 vs 0.784, P = 0.00007). Additionally, in the validation cohort, among the subgroup of 273 women carrying a fetus with aEFW ≥ 4000 g, the aEFW had no predictive power (AUC = 0.548), and the model performed significantly better (0.775, P = 0.0002). A risk-score threshold of 0.5 stratified 42.9% of deliveries to the high-risk group, which included 90.9% of ShD cases and all cases accompanied by maternal or newborn complications. A more specific threshold of 0.7 stratified only 27.5% of the deliveries to the high-risk group, which included 63.6% of ShD cases and all those accompanied by newborn complications.

CONCLUSION

We developed a ML model for prediction of ShD and, in a different cohort, externally validated its performance. The model predicted ShD better than did estimated fetal weight either alone or combined with maternal diabetes, and was able to stratify the risk of ShD and neonatal injury in the context of suspected macrosomia. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

'The obesity paradox': a reconsideration of obesity and the risk of preterm birth

OBJECTIVE

The association between obesity and spontaneous preterm births (sPTBs) has been shown to be influenced by obesity-attendant comorbidities. Our objective was to better understand the complex relationship of obesity and its attendant comorbidities with sPTBs.

STUDY DESIGN

A retrospective analysis utilizing maternally linked hospital and birth certificate records of 2 049 196 singleton California deliveries from 2007 to 2011. Adjusted relative risks (aRRs) for sPTBs were estimated using multivariate Poisson regression modeling.

RESULTS

Obese women had higher aRRs for sPTBs than their normal body mass index (BMI) controls. aRRs (95% confidence interval) increased with increasing BMI category: Obese I=1.10 (1.08 to 1.12); Obese II=1.15 (1.12 to 1.18); and Obese III=1.26 (1.22 to 1.30). When comparing only obese women without comorbidities to their normal BMI controls, aRRs reversed, that is, obese women had lower aRRs of sPTBs: Obese I=0.96 (0.94 to 0.98), Obese II=0.95 (0.91 to 0.98); and Obese III=0.98 (0.94 to 1.03). This same reversal of aRR direction was also observed among women with comorbidities: 0.92 (0.89 to 0.96); 0.89 (0.85 to 0.93); and 0.89 (0.85 to 0.93), respectively. Increasing BMI increased the aRRs for sPTBs among patients with gestational diabetes (P<0.05), while decreasing the risk among patients with chronic hypertension and pregnancy-related hypertensive disease (P<0.05).

CONCLUSIONS

The obesity and preterm birth paradox is an example of what has been described as 'Simpson's Paradox'. Unmeasured confounding factors mediated by comorbidities may explain the observed protective effect of obesity upon conditioning on the presence or absence of comorbidities and thus resolve the paradox.

Maternal First Trimester TSH Concentrations: Do They Affect Perinatal and Endocrine Outcomes?

We aimed to examine the distribution of 1(st) trimester TSH and evaluate its association with perinatal outcomes and future development of maternal thyrotoxicosis. This retrospective cohort study included data of all women without prior thyroid disease who delivered a singleton at our medical center from 1/2001 to 12/2011 and had a 1(st) trimester TSH<4.0 mU/l. Women were divided according to 1(st) trimester TSH concentrations into quartiles and by predefined TSH values (mU/l): 1) TSH<0.1; 2) TSH 0.11-0.2; 3) TSH 0.21-0.4; and 4) TSH 0.4-4. Obstetrical outcomes, hCG concentrations, and future thyroid status were collected from electronic medical records. A total of 13 841 women fulfilled the inclusion criteria. Mean maternal TSH concentration at 5 weeks of gestation was 2.09±0.83 mU/l and decreased to 1.29±0.87 mU/l in weeks 8-9 with an increase towards the end of the 1(st) trimester. Odds ratio for future thyrotoxicosis was 3.64 in the lowest compared to the highest TSH quartile and 10.03 in those with TSH<0.1 compared to TSH 0.41-4 mU/l. Rates of female fetuses were higher in the low TSH quartiles and in the lower TSH groups, however baby gender was not associated with increased risk of future thyrotoxicosis. Low maternal 1(st) trimester TSH quartiles or concentrations were not associated with adverse pregnancy outcome. Only a minor fraction of pregnant women with a low first tirmester TSH subsequently developed future thyrotoxicosis.

Hypersensitivity associated with sugammadex administration: a systematic review

Sugammadex is a drug used to reverse neuromuscular blockade induced by rocuronium or vecuronium. It has not yet been approved by the Food and Drug Administration in the USA due to concerns regarding hypersensitivity. The objective of this review was to identify similarities in the presentation of hypersensitivity reactions to sugammadex. A comprehensive search was performed in PubMed, Scopus and Web of Science for cases reporting hypersensitivity reactions to sugammadex. In addition, we contacted regulatory agencies and the company marketing the drug for unpublished reports. Reports were included if they were in English, primary investigations, lacked an alternative probable explanation for the reaction and included a comprehensive description of the hypersensitivity. We identified 15 cases of hypersensitivity following sugammadex administration. All cases that reported exact timing (14/15) occurred in 4 min or less. Most of the patients (11/15; 73%) met World Anaphylaxis Organization criteria for anaphylaxis. Awareness must be raised for the possibility of drug-induced hypersensitivity during the critical 5-min period immediately following sugammadex administration.

Effect of different dress style on vitamin D level in healthy young Orthodox and ultra-Orthodox students in Israel

Ultra-orthodox Jewish lifestyle, which encourages modest dress and indoor scholarly activity, represents a risk factor for vitamin-D deficiency. Our study in healthy young males from higher education religious institutions located in the same geographical area showed frequent and severe vitamin D deficiency, strongly correlated with the degree of sun exposure. However, PTH level was usually normal.

INTRODUCTION

Ultra-orthodox Jewish lifestyle encourages modest dress and indoor scholarly activity. As such, it represents a risk factor for vitamin-D deficiency, a worldwide problem previously underestimated in sunny countries. Our aim was to characterize the vitamin-D status of religious Jewish males according to sun exposure and outdoor activity, and study the correlation between serum 25-hydroxyvitamin D (25(OH) D) and PTH level.

METHODS

Seventy-four young adult males were recruited from three Jewish higher education institutions (Yeshiva) in Jerusalem. Yeshiva-A ultra-Orthodox students (aged 20.1 ± 0.6) wear traditional clothing, live in dormitories and stay mostly indoor. Yeshiva-B ultra-Orthodox students (aged 33.0 ± 4.2) dress similarly but have regular outdoor activities. Yeshiva-C religious students (aged 19 ± 2.0) participate in a mixed army/Yeshiva program. Weekly outdoor activity time and degree of sun exposure were estimated by questionnaire.

RESULTS

25(OH)D was 8.9 ± 3.6, 10.2 ± 5.7 and 21.7 ± 10.4 ng/ml (mean ± SD) in Yeshiva A, B and C. 25(OH)D was correlated with degree of sun exposure (r = 0.54, p < 0.0001) and inversely correlated with PTH (r = -0.3, p = 0.01). Levels below 20 ng/ml were considered as vitamin D deficiency. PTH was normal in 87% of vitamin D-deficient subjects from Yeshiva-A and Yeshiva-C (mean age 20), compared to 52% of Yeshiva-B students (mean age 33). Bone mineral density studied in a random subset (n = 14) of vitamin D-deficient subjects showed Z-scores of -1.5 ± 1.0, -1.8 ± 0.8, -2.1 ± 0.4 in femoral neck, spine and radius.

CONCLUSIONS

Severe vitamin-D deficiency is extremely prevalent in ultra-Orthodox males. Despite rare secondary hyperparathyroidism, they represent an important previously unrecognized high-risk group for metabolic bone disease.

Safety and efficacy of insulin detemir in clinical practice: 14-week follow-up data from type 1 and type 2 diabetes patients in the PREDICTIVE European cohort

PREDICTIVE (Predictable Results and Experience in Diabetes through Intensification and Control to Target: An International Variability Evaluation) is a large, multi-national, open-label, prospective, observational study assessing the safety and efficacy of insulin detemir in clinical practice. A total of 20,531 patients with type 1 or 2 diabetes from 11 countries were prescribed insulin detemir and followed up after a mean of 14.4 weeks. The primary endpoint was incidence of serious adverse drug reactions (SADRs), including major hypoglycaemia. Secondary endpoints were: haemoglobin A(1c) (HbA(1c)), mean self-monitored fasting glucose, within-patient fasting glucose variability and body weight change. Two hundred and fourteen patients (1%) reported SADRs, including major hypoglycaemia. The incidence of major hypoglycaemic episodes was reduced from 3.0/patient-year at baseline to 0.7/patient-year at follow-up in type 1 patients (p < 0.0001), and from 0.8 to 0.1/patient-year in type 2 patients (p < 0.0001). Insulin detemir improved glycaemic control in type 1 and type 2 patients, with reductions in mean HbA(1c) (0.5% and 0.9%, respectively, p < 0.0001 for both), fasting glucose (1.7 and 2.6 mmol/l, p < 0.0001 for both) and within-patient fasting glucose variability (0.7 and 0.5 mmol/l, p < 0.0001 for both). There was a small decrease in mean body weight in both type 1 and 2 patients (-0.1 kg, p < 0.01 and -0.4 kg, p < 0.0001 respectively). Insulin detemir was used once- or twice-daily in 49% and 50% of type 1 patients, and 77% and 23% of type 2 diabetes patients, respectively. The 14-week observations from PREDICTIVE support clinical trial data showing that insulin detemir improves glycaemic control, with a lowered risk of hypoglycaemia and no weight gain.

Exhausting fatigue influences F-wave and peripheral conduction velocity, following lumbar radiculopathy

PURPOSE

The purpose of the study was to determine whether mechanical nerve root compression could indirectly contribute to early muscle fatigue because of impaired activation.

METHOD

The patients' two legs and the control group's dominant leg were subjected to exhausting foot dorsiflexion against 2 kg weight. Electrophysiological parameters were measured under three conditions: before, upon completion of, and five minutes after the exhausting effort (i.e. causing unbearable fatigue). The study was performed in a warm room (24 degrees C), in the EMG laboratory of a rehabilitation centre using standard equipment. Eighteen patients participated in the study (12 males and six females, mean age 47.8 +/- 12.0 years). They suffered from lumbar radiculopathy and unilateral complaints at the L4, L5 innervation territory. There were 22 matched controls (18 males and 4 females, mean age 44.4 +/- 9.9 years) that were healthy subjects. The patients' two legs and the dominant leg of the control participants were tested. The peroneal nerve was stimulated supra-maximally, behind the fibular head. Recording the activity of the anterior tibial muscle served to calculate F-wave latency, the conduction velocity of the nerve and muscle complex (NMCV), the compound muscle action potential (CMAP) amplitude and the exhaustion time.

RESULTS

Following the exhausting fatigue, the symptomatic, asymptomatic, and control legs exhibited a significant decrease in NMCV and reduced CMAP amplitude (p < 0.05). In each condition (rest, effort, recovery), the patients' two leg types exhibited similar NMCV (symptomatic vs asymptomatic), yet each of these two types was significantly slower than the controls' NMCV. A significant prolongation of F-wave latency after an exhausting effort was found in the symptomatic legs.

CONCLUSIONS

Our results suggest that a continuous exhausting effort impairs F-wave latency and NMCV, presumably by decreasing the proportion of fast conducting nerve fibres. Peroneal nerve root compression can contribute to early fatigue of the respective muscles.

Arthrodesis with the Ilizarov device after failed knee arthroplasty

Thirteen patients with failed total knee arthroplasty (TKA) due to infection (12 patients) or aseptic loosening (1 patient) underwent arthrodesis using the Ilizarov external fixator. Solid fusion was achieved in all patients with an average healing time of 27.6 weeks. Patients spent an average 18.8 weeks in the fixator followed by an average 8.8 weeks in a plaster cylinder cast. Five patients had a pin tract infection and one a superficial wound infection. One patient had 15 degrees recurvatum after surgery that was gradually corrected by adding a hinge system to the fixator. Average shortening of the affected limb was 3.7 cm (range: 1-6 cm). The Ilizarov fixator for knee arthrodesis after failed TKA produced favorable results and should be considered for use by surgeons familiar with the technique.

[Diagnosis and therapy in acute stroke: a rehabilitation center viewpoint]

The extent of the diagnostic work-up of patients with acute stroke was evaluated in 101 patients admitted for rehabilitation during a 4-month period in 1997. This included specific blood tests and neuro- and cardiac imaging, and compared the extent of work-up in a community hospital versus a rehabilitation center. Comparisons were also made with similar investigations 10 and 20 years earlier. Results demonstrated that the trend to admit younger stroke patients (< 50 years) to neurological (as opposed to medical) departments observed between 1977-1987 persisted in 1997. The use of CT scan increased dramatically from 1977 to 1987 (19% vs 78%), and in 1997 was actually 100%. The use of carotid duplex and echocardiography increased steadily during the 3 decades reaching 26% and 28% respectively. Tests for thrombophilia were seldom done. However, in neurological departments it was done in about 50% of the younger stroke patients. In neurology departments carotid duplex was done 2 to 3 times more often than in medical departments. During rehabilitation imaging tests were done once or more in almost half the patients. The results and those of additional blood tests, have led to modification of antithrombotic treatment in 14% of the younger group and 4% of the older group. We have clearly shown that while stroke work-up has become more comprehensive in recent years, there is still much to do in this field. Stroke units or teams in our general hospitals will increase stroke awareness, improve work-up and hasten definitive treatment.

Brachial biceps tendon injuries in young female high-level tennis players

AIM

To evaluate brachial biceps tendon lesions in four young female tennis players who complained about anterior shoulder pain on their dominant side.

METHODS

Medical and sport's activity history, palpation of the painful zone, Ghilchrist (palm-up) test, and brachial biceps contraction against resistance were performed.

RESULTS

The two girls who suffered from mild tenderness in the bicipital groove and over the anterior aspect of the upper arm and the shoulder joint, had tendinitis of the long biceps head. The two girls who suffered from severe tenderness just under the groove, had a partial tear in the long head of the biceps. Ghilchrist test was positive in all girls.

CONCLUSION

Tennis players can have shoulder pain without clear history of trauma. Pain occurred probably as a result of technical errors or use of inadequate equipment.

[Suprascapular nerve entrapment in a basketball player]

A basketball player was shown to have a suprascapular nerve lesion without any history of shoulder girdle trauma. This acute neuropathy, never previously described in basketball players, is a result of repeated micro-trauma, due to nerve traction over the coracoid notch during violent movement ("dunking" most probably). Clinically, he was unable to abduct his arm and had some difficulty in external rotation. He developed atrophy in both the supra- and the infraspinatus muscles. Nerve conduction latency to the supraspinatus muscle was 8.0 ms, and to the infraspinatus, 8.5 ms. The compound muscle action potential registered in the supraspinatus was 1.224 mV, and in the infraspinatus, 1.237 mV. After 3 weeks of inactivity, recovery was spontaneous and practically complete.

Cervical spine movements in hemiparetic patients

Cervical spine movements in 38 severe hemiparetic patients were measured, at least 6 months after the breakout of the first and unique cerebral vascular accident. The purpose was to investigate if there was any difference in maximal head rotation and lateral bending movements between the plegic and the sound side. The measurements were taken by a spherical compass attached to a cubic protractor with a small mobile ball inside, both fixed to the patient's head. All the tests were done several months after the end of the rehabilitation process and compared to those obtained in 29 orthopaedic patients without hemiparesis (control group). The results obtained demonstrate that the cervical spine movements in hemiparetic patients are minimally limited and manifested only in lateral bending towards the sound side (p = 0.042). The difference was more significant after 1 year or more of hemiparesis (p = 0.013). In the control group the differences in the external rotation angle and lateral bending angle between the right and left sides were not significant.

Pre-clinical Cushing's syndrome: an unexpected frequent cause of poor glycaemic control in obese diabetic patients

OBJECTIVE

Autonomous cortisol secretion without clinical stigmata of Cushing's syndrome (CS) has been recently recognized and termed pre-clinical or sub-clinical CS. The common assumption is that CS is an extremely rare cause of uncontrolled diabetes; however, the prevalence of this entity has not been studied. We assessed the prevalence of pre-clinical CS among obese patients with uncontrolled diabetes.

PATIENTS AND DESIGN

(1) In a retrospective analysis, the medical records of 63 patients with endogenous CS were reviewed. (2) In a cross-sectional study, 90 obese patients (BMI > 25 kg/m2) followed in a University Hospital and the local Health Fund endocrine and diabetes clinics, with poorly controlled diabetes (glycosylated haemoglobin > 9%), underwent an overnight 1 mg dexamethasone suppression. In patients with non-suppressible cortisol levels (> 140 nmol/l), Liddle's 2 and 8 mg dexamethasone suppression tests and imaging studies were performed.

MEASUREMENTS

The prevalence of poorly controlled diabetes, the major presenting symptom of CS, was assessed in the retrospective analysis. The prevalence of "true' CS and the false positive rate in the overnight dexamethasone suppression test were calculated. The endocrine evaluation of the patients with pre-clinical CS and the effects of surgical cure on glycaemic control are described.

RESULTS

In the retrospective analysis, 11 (17.5%) had diabetes and 2 (3.2%) lacked the classic physical characteristics of the syndrome. In the cross-sectional study, 4 patients failed to suppress plasma cortisol (< 140 nmol/l). In one patient the diagnosis of CS was not confirmed by a standard Liddle's test and was therefore considered false positive. In the other 3, the diagnosis of CS was confirmed (prevalence of 3.3%, 95% confidence interval 1-9%). In all other patients the overnight cortisol suppression test was normal (cortisol level 47.3 +/- 2.5 nmol/l (mean +/- SEM)). After surgical treatment of CS, glycaemic control was markedly improved in all 5 patients (2 from retrospective and 3 from cross-sectional studies).

CONCLUSIONS

The prevalence of pre-clinical Cushing's syndrome in obese patients with poorly controlled diabetes appears to be considerably higher than previously believed. The overnight dexamethasone suppression test proved to be a simple, sensitive and highly specific screening test for Cushing's syndrome despite the presence of obesity and hyperglycaemia.

Relationship between muscular tone, movement and periarticular new bone formation in postcoma-unaware (PC-U) patients

Forty-eight post-traumatic brain-injured patients in postcoma-unawareness (PC-U) state, are included in this study. All recovered consciousness at least 1 month after the accident. The muscular tone and movement of all limbs was examined. At least two X-rays of the big joints were taken. Periarticular new bone formation appeared in 26 patients. This heterotopic ossification occurs in severely injured patients, primarily in proximal joints of the upper and lower extremities. Their aetiology in brain injury is unknown. Risk factors include prolonged coma, tone and movements in the involved extremity, and associated fractures. We found that the appearance of periarticular new bone formation had a close correlation with pathological movement (paresis or plegia), a borderline correlation with hypertonus, and no correlation with hypotonus or with associated fractures.

[Influence of muscle tone and force on ossification in postcomatose patients]

68 post-traumatic brain-injured patients in postcomatose unawareness (PCU) states were admitted during 1982-1987. 32 of them also suffered from fractures of the long bones and pelvis (total of 51 limbs). The muscle tone and force of all limbs were examined and x-rays of the large joints and of the fractures were taken periodically. Periarticular new-bone formation appeared in 32 patients. Normal callus developed in 41 fractured limbs and hypertrophic callus in 18. We found that pathological muscular tone (hypertonus and hypotonus) and pathologically decreased muscle force (paresis and plegia) were closely correlated with the appearance of periarticular new-bone formation. The extent of callus formation was not correlated with muscle tone and force.

Falciparum malaria-induced hypoglycaemia in a diabetic patient

We report a patient with diabetes mellitus who suffered severe falciparum malaria complicated by profound and persistent hypoglycaemia. The hypoglycaemia evolved before therapy with quinine was begun and resolved with eradication of the parasitaemia. The patient reverted to her baseline hyperglycaemia despite continuation of quinine. This case illustrates the critical role of falciparum malaria in the pathogenesis of malaria-associated hypoglycaemia, rather than quinine-mediated mechanisms. Anticipation of hypoglycaemia in falciparum malaria and its vigorous treatment may improve the poor prognosis associated with this complication.