Deep Learning Auto-Segmentation Network for Pediatric Computed Tomography Data Sets: Can We Extrapolate From Adults?

PURPOSE: Artificial intelligence (AI)-based auto-segmentation models hold promise for enhanced efficiency and consistency in organ contouring for adaptive radiation therapy and radiation therapy planning. However, their performance on pediatric computed tomography (CT) data and cross-scanner compatibility remain unclear. This study aimed to evaluate the performance of AI-based auto-segmentation models trained on adult CT data when applied to pediatric data sets and explore the improvement in performance gained by including pediatric training data. It also examined their ability to accurately segment CT data acquired from different scanners. METHODS AND MATERIALS: Using the nnU-Net framework, segmentation models were trained on data sets of adult, pediatric, and combined CT scans for 7 pelvic/thoracic organs. Each model was trained on 290 to 300 cases per category and organ. Training data sets included a combination of clinical data and several open repositories. The study incorporated a database of 459 pediatric (0-16 years) CT scans and 950 adults (>18 years), ensuring all scans had human expert ground-truth contours of the selected organs. Performance was evaluated based on Dice similarity coefficients (DSC) of the model-generated contours. RESULTS: AI models trained exclusively on adult data underperformed on pediatric data, especially for the 0 to 2 age group: mean DSC was below 0.5 for the bladder and spleen. The addition of pediatric training data demonstrated significant improvement for all age groups, achieving a mean DSC of above 0.85 for all organs in every age group. Larger organs like the liver and kidneys maintained consistent performance for all models across age groups. No significant difference emerged in the cross-scanner performance evaluation, suggesting robust cross-scanner generalization. CONCLUSIONS: For optimal segmentation across age groups, it is important to include pediatric data in the training of segmentation models. The successful cross-scanner generalization also supports the real-world clinical applicability of these AI models. This study emphasizes the significance of data set diversity in training robust AI systems for medical image interpretation tasks.

Objective assessment of control compared with clinical triple office control score in children with intermittent exotropia.

Poor control of intermittent exotropia may be used as an indication for surgery. However, control fluctuates during the day and from day to day. The standardized triple office control score (mean of three scores on a 6-point ordinal scale) is representative of repeated assessments throughout the day, but lacks validation against an objective measure of eye movements. We report the agreement between the triple office control score measured by the referring eyecare professional and lab-measured vergence instability using an EyeLink video eye tracker. Near and distance triple office control scores were moderately correlated with vergence instability. Near, but not distance, triple office control score was moderately correlated with the percentage of time intermittent exotropia was manifest during EyeLink recording. Larger triple office control scores for intermittent exotropia provide a meaningful description of larger vergence instability, supporting its use in clinical decisions and as a measure in clinical trials.

Chest CT features and functional correlates of COVID-19 at 3 months and 12 months follow-up.

Long-term pulmonary sequelae of Coronavirus 2019 (COVID-19) remain unclear. Thus, we aimed to establish post-COVID-19 temporal changes in chest computed tomography (CT) features of pulmonary fibrosis and to investigate associations with respiratory symptoms and physiological parameters at 3 and 12 months' follow-up. Adult patients who attended our initial COVID-19 follow-up service and developed chest CT features of interstitial lung disease, in addition to cases identified using British Society of Thoracic Imaging codes, were evaluated retrospectively. Clinical data were gathered on respiratory symptoms and physiological parameters at baseline, 3 months, and 12 months. Corresponding chest CT scans were reviewed by two thoracic radiologists. Associations between CT features and functional correlates were estimated using random effects logistic or linear regression adjusted for age, sex and body mass index. In total, 58 patients were assessed. No changes in reticular pattern, honeycombing, traction bronchiectasis/bronchiolectasis index or pulmonary distortion were observed. Subpleural curvilinear lines were associated with lower odds of breathlessness over time. Parenchymal bands were not associated with breathlessness or impaired lung function overall. Based on our results, we conclude that post-COVID-19 chest CT features of irreversible pulmonary fibrosis remain static over time; other features either resolve or remain unchanged. Subpleural curvilinear lines do not correlate with breathlessness. Parenchymal bands are not functionally significant. An awareness of the different potential functional implications of post-COVID-19 chest CT changes is important in the assessment of patients who present with multi-systemic sequelae of COVID-19 infection.

Ticagrelor or prasugrel versus clopidogrel in patients undergoing percutaneous coronary intervention for chronic coronary syndromes.

BACKGROUND: Potent P2Y12 inhibitors such as ticagrelor and prasugrel are superior to clopidogrel in acute coronary syndrome (ACS) patients treated with percutaneous coronary intervention (PCI). Whether this benefit extends to a patient population with chronic coronary syndromes (CCS) is unclear. AIMS: We sought to compare the safety and efficacy of prasugrel and ticagrelor versus clopidogrel in patients undergoing PCI for CCS. METHODS: Consecutive patients undergoing PCI for CCS at a tertiary centre between 2014 and 2019 who were discharged on prasugrel or ticagrelor were compared with those on clopidogrel. The primary endpoint was the composite of death and myocardial infarction (MI), with secondary outcomes including rates of bleeding, stroke, and target vessel revascularisation at 1 year. RESULTS: Overall, 11,508 patients were included in the study (ticagrelor/prasugrel n=2,860 [24.9%], clopidogrel n=8,648 [75.1%]) with an increasing frequency of potent P2Y12 inhibitor use over the study period (ptrend<0.001). Clopidogrel was used more frequently in patients with multimorbid risk factors, whereas anatomical or procedural complexity was associated with ticagrelor/prasugrel use (left main PCI, bifurcation PCI, number of lesions, rotational atherectomy). No difference in the incidence of death or MI was noted across the groups (ticagrelor/prasugrel vs clopidogrel: 2.7% vs 3.1%, adjusted hazard ratio [adjHR] 0.86, 95% confidence interval [CI]: 0.62-1.17; p=0.33) or secondary outcomes including bleeding (adjHR 0.75, 95% CI: 0.46-1.21; p=0.23) on propensity score stratification analysis. Additionally, no difference in the primary outcome was observed across subgroups, including those undergoing complex PCI. CONCLUSIONS: Ticagrelor and prasugrel are increasingly used in patients with CCS undergoing PCI with similar 1-year efficacy and safety when compared to clopidogrel. Whether use of these agents can be beneficial in patients undergoing PCI for CCS with a high thrombotic and low bleeding risk warrants further study.

M ycobacterium avium complex genomics and transmission in a London hospital.

BACKGROUND: Non-tuberculous mycobacteria (NTM) are environmental microorganisms and opportunistic pathogens in individuals with pre-existing lung conditions such as cystic fibrosis (CF) and non-CF bronchiectasis. While recent studies of Mycobacterium abscessus have identified transmission within single CF centres as well as nationally and globally, transmission of other NTM species is less well studied. METHODS: To investigate the potential for transmission of the Mycobacterium avium complex (MAC) we sequenced 996 isolates from 354 CF and non-CF patients at the Royal Brompton Hospital (London, UK; collected 2013-2016) and analysed them in a global context. Epidemiological links were identified from patient records. Previously published genomes were used to characterise global population structures. RESULTS: We identified putative transmission clusters in three MAC species, although few epidemiological links could be identified. For M. avium, lineages were largely limited to single countries, while for Mycobacterium chimaera, global transmission clusters previously associated with heater-cooler units (HCUs) were found. However, the immediate ancestor of the lineage causing the major HCU-associated outbreak was a lineage already circulating in patients. CONCLUSIONS: CF and non-CF patients shared transmission chains, although the lack of epidemiological links suggested that most transmission is indirect and may involve environmental intermediates or asymptomatic carriage in the wider population.

Diagnosis and management of non-cystic fibrosis bronchiectasis.

Bronchiectasis is a heterogeneous and increasingly prevalent chronic pulmonary disease that is associated with significant morbidity. In this review, we outline how patients with bronchiectasis may present clinically and describe an approach to its diagnosis, including how to identify an underlying aetiology. We discuss the important considerations when treating either acute exacerbations or stable disease and provide an overview of the role of long-term antimicrobials, airway clearance methods and other supportive management.

Patterns of myocardial injury in recovered troponin-positive COVID-19 patients assessed by cardiovascular magnetic resonance.

BACKGROUND: Troponin elevation is common in hospitalized COVID-19 patients, but underlying aetiologies are ill-defined. We used multi-parametric cardiovascular magnetic resonance (CMR) to assess myocardial injury in recovered COVID-19 patients. METHODS AND RESULTS: One hundred and forty-eight patients (64 ± 12 years, 70% male) with severe COVID-19 infection [all requiring hospital admission, 48 (32%) requiring ventilatory support] and troponin elevation discharged from six hospitals underwent convalescent CMR (including adenosine stress perfusion if indicated) at median 68 days. Left ventricular (LV) function was normal in 89% (ejection fraction 67% ± 11%). Late gadolinium enhancement and/or ischaemia was found in 54% (80/148). This comprised myocarditis-like scar in 26% (39/148), infarction and/or ischaemia in 22% (32/148) and dual pathology in 6% (9/148). Myocarditis-like injury was limited to three or less myocardial segments in 88% (35/40) of cases with no associated LV dysfunction; of these, 30% had active myocarditis. Myocardial infarction was found in 19% (28/148) and inducible ischaemia in 26% (20/76) of those undergoing stress perfusion (including 7 with both infarction and ischaemia). Of patients with ischaemic injury pattern, 66% (27/41) had no past history of coronary disease. There was no evidence of diffuse fibrosis or oedema in the remote myocardium (T1: COVID-19 patients 1033 ± 41 ms vs. matched controls 1028 ± 35 ms; T2: COVID-19 46 ± 3 ms vs. matched controls 47 ± 3 ms). CONCLUSIONS: During convalescence after severe COVID-19 infection with troponin elevation, myocarditis-like injury can be encountered, with limited extent and minimal functional consequence. In a proportion of patients, there is evidence of possible ongoing localized inflammation. A quarter of patients had ischaemic heart disease, of which two-thirds had no previous history. Whether these observed findings represent pre-existing clinically silent disease or de novo COVID-19-related changes remain undetermined. Diffuse oedema or fibrosis was not detected.

Respiratory Virus Infections in Asthma: Research Developments and Therapeutic Advances.

In this review, we discuss the latest developments in research pertaining to virus-induced asthma exacerbations and consider recent advances in treatment options. Asthma is a chronic disease of the airways that continues to impose a substantial clinical burden worldwide. Asthma exacerbations, characterised by an acute deterioration in respiratory symptoms and airflow obstruction, are associated with significant morbidity and mortality. These episodes are most commonly triggered by respiratory virus infections. The mechanisms underlying the pathogenesis of virus-induced exacerbations have been the focus of extensive biomedical research. Developing a robust understanding of the interplay between respiratory viruses and the host immune response will be critical for developing more efficacious, targeted therapies for exacerbations. CONCLUSION: There has been significant recent progress in our understanding of the mechanisms underlying virus-induced airway inflammation in asthma and these advances will underpin the development of future clinical therapies.

Recurrent Stroke Due to Pulmonary Vein Thrombosis in a Patient with Metastatic Lung Adenocarcinoma.

BACKGROUND Pulmonary vein thrombosis (PVT) is a rare clinical entity. Etiologies include malignancy, hyper-viscosity syndromes, and other etiologies. Patients may present with dyspnea, cough, or hemoptysis. CASE REPORT We present a case of a 64-year-old man with a history of metastatic lung cancer diagnosed with PVT through transesophageal echocardiography (TEE) and complicated by 2 cerebrovascular accidents. The patient had a complicated hospital course and died later due to his malignancy burden and overall condition, despite anticoagulation therapy. CONCLUSIONS Patients with PVT are often asymptomatic or may have a nonspecific clinical presentation. Anticoagulation should be considered in patients with PVT given the life-threatening complications such as peripheral embolization. More research is needed to address this potentially catastrophic finding.

Large Right Coronary Artery Aneurysm.

Complications of aneurysm include thrombosis and distal embolization, rupture, and vasospasm. The natural history and prognosis remain obscure. Controversies persist regarding the use of surgical or medical management.

Birt-Hogg-Dubé syndrome presenting with spontaneous pneumothorax and extensive pulmonary cysts in the absence of skin lesions or renal pathology.

Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant condition which classically manifests with skin lesions such as fibrofolliculomas, pulmonary cysts that predispose to spontaneous pneumothorax and an increased risk of developing renal cell carcinoma. We describe the case of a patient who presented with a spontaneous pneumothorax on a background of multiple lung cysts, in the absence of cutaneous fibrofolliculomas and renal tumours. A germline mutation in the folliculin FLCN gene was subsequently identified, confirming BHD syndrome. Our case highlights the importance of considering a broad differential diagnosis for the cause of a spontaneous pneumothorax in the presence of unexplained cystic lung disease and emphasises the value of maintaining a high index of clinical suspicion for inherited causes of pneumothoraces.

Cardiovascular risk prediction in the elderly.

Heart failure (HF) in the elderly, besides being a leading cause of mortality and morbidity, is rapidly increasing in prevalence with patients aged 65 and older accounting for more than 75% of heart failure hospitalizations. Elderly patients have historically been unrepresented in clinical HF trials and often present with multiple comorbidities, including frailty, depression, nutritional, functional and cognitive impairments. Additionally, pharmacologic challenges such as adherence to therapy, polypharmacy, altered drug pharmacokinetics and/or renal derangements make them less likely to receive guideline-directed medical therapies for HF. Recognition of these various interrelated domains is key and should prompt a multidisciplinary, holistic management approach so as to optimize prognosis in this vulnerable subset of the population.

Orbital Inflammatory Syndrome and Anterior Uveitis: A Case Series.

PURPOSE: To describe four cases of orbital inflammatory syndrome (OIS) with associated anterior uveitis that have presented within 2 years to our practice. METHODS: Charts of patients diagnosed with OIS from June 2013 to May 2015 were reviewed. RESULTS: Four patients, three children and one adult, presented with orbital swelling, pain, and varying degrees of vision loss. Treatment with intravenous methylprednisolone resulted in significant symptomatic improvement in all cases initially; when symptoms recurred, the patients had evidence of anterior uveitis. With continued systemic therapy and the addition of topical prednisolone, the patients all achieved control of their uveitis and OIS and are well controlled with regular outpatient follow-up. CONCLUSIONS: Reports of OIS-associated with uveitis are relatively rare. The presentation of three pediatric patients and one adult patient to the same practice with OIS and secondary uveitis within a 2-year period may indicate that the association is underreported.

Development of a Chest Wall Protector Effective in Preventing Sudden Cardiac Death by Chest Wall Impact (Commotio Cordis).

OBJECTIVE: Commotio cordis, sudden death with chest impact, occurs clinically despite chest wall protectors worn in sports. In an experimental model of commotio cordis, commercially available chest wall protectors failed to prevent ventricular fibrillation (VF). The goal of the current investigation was to develop a chest wall protector effective in the prevention of commotio cordis. DESIGN: In the Tufts experimental model of commotio cordis the ability of chest protectors to prevent VF was assessed. Impacts were delivered with a 40-mph lacrosse ball, timed to the vulnerable period for VF. INTERVENTION: A chest wall protector or no chest wall protector (control) was randomly assigned to be placed over the chest. Four iterative series of 2 to 4 different chest wall material combinations were assessed. Materials included 3 different foams (Accelleron [Unequal Technologies, Glen Mills, PA], closed cell high density foam; Airilon [Unequal Technologies, Glen Mills, PA], closed cell low density soft foam; and an open cell memory foam) that were adhered to a layer of TriDur (Unequal Technologies, Glen Mills, PA), a flexible elastomeric coated aramid that was bonded to a semirigid polypropylene polymer (ImpacShield, Unequal Technologies, Glen Mills, PA). MAIN OUTCOME MEASURE: Induction of VF by chest wall impact was the primary outcome. RESULTS: Of 80 impacts without chest protectors, 43 (54%) resulted in VF. Ventricular fibrillation with chest protectors ranged from a high of 60% to a low of 5%. Of 12 chest protectors assessed, only 3 significantly lowered the risk of VF compared with impacts without chest protectors. These 3 chest protectors were combinations of Accelleron, Airilon, TriDur, and ImpacShield of different thicknesses. Protection increased linearly with the thicker combinations. CONCLUSIONS: Effective protection against VF with chest wall protection can be achieved in an experimental model of commotio cordis. CLINICAL RELEVANCE: Chest protector designs incorporating these novel materials will likely be effective in the prevention of commotio cordis on the playing field.

A curious case of cholestasis: oral terbinafine associated with cholestatic jaundice and subsequent erythema nodosum.

Terbinafine is a commonly prescribed antifungal agent used in the treatment of trichophytic onychomycosis and chronic cutaneous mycosis that are resistant to other treatments. This case report highlights a rarely documented but important adverse hepatic reaction that was caused by the use of oral terbinafine. A woman in her thirties presented with a 3-week history of jaundice, malaise, itching, nausea, decreased appetite, weight loss, dark orange urine and intermittent non-radiating epigastric pain. She had recently finished a 3-week course of oral terbinafine for a fungal nail infection. Liver biopsy findings were consistent with chronic active hepatitis secondary to a drug reaction. A few days after initial presentation, the patient developed erythema nodosum. Delayed development of erythema nodosum secondary to terbinafine could not be excluded.