Publications by authors named "Stephen Lyen"

Background: Because chest CT scan has largely supplanted surgical lung biopsy for diagnosing most cases of interstitial lung disease (ILD), tools to standardize CT scan interpretation are urgently needed.

Research Question: Does a deep learning (DL)-based classifier for usual interstitial pneumonia (UIP) derived using CT scan features accurately discriminate radiologist-determined visual UIP?

Study Design And Methods: A retrospective cohort study was performed. Chest CT scans acquired in individuals with and without ILD were drawn from a variety of public and private data sources.

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Objective: To assess the diagnostic accuracy and clinical impact of automated artificial intelligence (AI) measurement of thoracic aorta diameter on routine chest CT.

Methods: A single-centre retrospective study involving three cohorts. 210 consecutive ECG-gated CT aorta scans (mean age 75 ± 13) underwent automated analysis (AI-Rad Companion Chest CT, Siemens) and were compared to a reference standard of specialist cardiothoracic radiologists for accuracy measuring aortic diameter.

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Abernethy malformation, or congenital extrahepatic portosystemic venous shunt, is a rare anomaly involving the portal venous system. Despite its rarity, it is increasingly being reported, and therefore, it is important to diagnose given the potential adverse clinical consequences if left untreated. It has a spectrum of presentations, ranging from complete lack of symptoms, to causing hepatic carcinoma, hepatic encephalopathy, severe pulmonary hypertension, and diffuse pulmonary arteriovenous malformation.

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Background: When patients with Fontan circulation require a computed tomographic pulmonary angiogram (CTPA), there are significant challenges in achieving adequate contrast opacification due to the altered anatomical connections. This study used Time Resolved Angiography with Interleaved Stochastic Trajectories (TWIST) Magnetic Resonance Angiography (MRA) to examine contrast circulation in a cohort of patients with Fontan circulation who were having routine MRI follow up to inform the contrast timing of any subsequent CT.

Methods: This is a single centre, cross-sectional, observational, retrospective study.

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Background: It has been estimated that 20-30% of repaired aortic coarctation (CoA) patients develop hypertension, with significant cardiovascular morbidity and mortality. Vertebral artery hypoplasia (VAH) with an incomplete posterior circle of Willis (ipCoW; VAH + ipCoW) is associated with increased cerebrovascular resistance before the onset of increased sympathetic nerve activity in borderline hypertensive humans, suggesting brainstem hypoperfusion may evoke hypertension to maintain cerebral blood flow: the "selfish brain" hypothesis. We now assess the "selfish brain" in hypertension post-CoA repair.

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Loeys-Dietz syndrome (LDS) is a recently described genetic connective tissue disorder with a wide spectrum of multisystem involvement. LDS is characterized by rapidly progressive aortic and peripheral arterial aneurysmal disease. LDS and the other inherited aortopathies such as Marfan syndrome have overlapping phenotypic features.

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Introduction: The purpose of this study was to determine the impact of interstitial lung disease (ILD) on radiation pneumonitis (RP) and overall survival (OS) in lung stereotactic body radiation therapy (SBRT).

Methods: Patients treated with lung SBRT from 2004 to 2015 were included. Pretreatment computed tomography scans were reviewed and classified for interstitial changes by thoracic radiologists using American Thoracic Society guidelines and Washko and Kazerooni scores.

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Purpose: Transthoracic needle biopsy (TTNB) is an established procedure in the management of pulmonary nodules. The most common complications are directly related to crossing the lung or visceral pleura during the biopsy. In this study, we describe the use of carbon dioxide instead of room air to create a protective "capnothorax" during TTNB.

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The case is presented of a non-infectious anterior mitral valve leaflet diverticulum, which appeared as symptomatic mitral stenosis. Unlike previous reports, there was no histological myxomatous degeneration of the valve. To the authors' knowledge, this is the first time a mitral valve diverticulum resulting in severe mitral stenosis has been reported in the literature.

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Aims: In hypertension, the presence of left ventricular (LV) strain pattern on 12-lead electrocardiogram (ECG) carries adverse cardiovascular prognosis. The underlying mechanisms are poorly understood. We investigated whether hypertensive ECG strain is associated with myocardial interstitial fibrosis and impaired myocardial strain, assessed by multi-parametric cardiac magnetic resonance (CMR).

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Objective: Myocardial intracellular/extracellular structure and aortic function were assessed among hypertensive left ventricular (LV) phenotypes using cardiovascular magnetic resonance (CMR).

Methods: An observational study from consecutive tertiary hypertension clinic patients referred for CMR (1.5 T) was performed.

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Cardiovascular magnetic resonance (CMR) is an established non-invasive technique to comprehensively assess cardiovascular structure and function in a variety of acquired and inherited cardiac conditions. A significant amount of the neck, thorax and upper abdomen are imaged at the time of routine clinical CMR, particularly in the initial multi-slice axial and coronal images. The discovery of unsuspected disease at the time of imaging has ethical, financial and medico-legal implications.

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Objectives: Our aim was to retrospectively evaluate non-stent graft closure of ascending aortic pseudoaneurysms at our center over a 10-year period, and describe a combined device occlusion and coil embolization technique.

Background: Aortic pseudoaneurysms (APAs) are a rare complication post cardiothoracic surgery, but can have fatal complications. There is increasing use of percutaneous interventional techniques for occlusion of aortic pseudoaneurysms in patients who are considered unsuitable for surgery.

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Aims: We sought to determine the prevalence of asymmetric hypertensive heart disease (HHD) overlapping morphologically with hypertrophic cardiomyopathy (HCM) and to determine predictors of this pattern of hypertensive remodelling.

Methods And Results: One hundred and fifty hypertensive patients underwent 1.5 T cardiovascular magnetic resonance imaging.

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We report a case of acute coronary syndrome secondary to intermittent extrinsic compression of the left anterior descending coronary artery by inward-pointing rib exostosis in an 18-year-old woman during forceful repeated expiration in labour. The diagnosis was achieved using multimodality noninvasive cardiac imaging. In particular, we demonstrated the novel role of expiratory-phase cardiac computed tomography in confirming the anatomical relationship of the bony exostosis to the left anterior descending coronary artery.

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Introduction: Our aim was to evaluate the reproducibility and accuracy of using short-axis and axial (transaxial) plane for magnetic resonance imaging analysis in adult patients referred for assessment of right ventricular (RV) structure and function.

Methods: Twenty consecutive subjects (10 male, 10 female, mean age 32.2 ± 14.

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Introduction: Animal studies have shown Zoledronic Acid (ZA) may diminish pleural fluid accumulation and tumour bulk in malignant pleural disease (MPD). We performed a pilot study to evaluate its effects in humans.

Methods: We undertook a single centre, double-blind, placebo-controlled trial in adults with MPD.

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Cardiac valve cysts are rare beyond infancy. The tricuspid and mitral valve are the most common sites, with few reported cases of pulmonary valve cysts in the literature. This case illustrates a pulmonary valve cyst mimicking a tumour in a child 13 years after cardiac surgery.

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