Publications by authors named "Kelvin K Yap"

Nodular soft tissue pleural thickening on imaging is highly suggestive of malignancy, of which pleural malignant mesothelioma and metastatic disease are differentials. We present the case of a 71-year-old male who presented with acute worsening of shortness of breath associated with a recurrent left pleural effusion post-pleurocentesis. He was an ex-smoker with previous asbestos exposure.

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Introduction: Patients with severe aortic stenosis (AS) require multi-detector computed tomography (MDCT) when considered for transcatheter aortic valve implantation (TAVI). Incidental findings on MDCT are common given the age group and region imaged. Our aim was to evaluate the frequency and outcome of incidental findings (IF) identified on MDCT and the impact on survival.

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Introduction: The prevalence of incidental F-fluorodeoxyglucose (FDG)-avid findings on positron emission tomography-computed tomography (PET/CT) has been extensively described. Few studies, however, have assessed the prevalence and significance of non-FDG-avid findings; pathology that is identified on review of the low-dose, non-contrast CT. The aim of this study was to determine the overall prevalence of non FDG-avid incidental findings on PET/CT and the prevalence of 'clinically significant' non FDG-avid pathology.

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Intraventricular lesions of the central nervous system (CNS) can present a diagnostic challenge due to a range of differential diagnoses and radiological appearances. Both CT and MRI imaging findings, in combination with location and patient's age, can help limit the differentials. This pictorial essay presents the salient radiological features, location and demographics of the more common intraventricular lesions of the brain.

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Introduction: In nuclear medicine, single-photon-emission computed tomography (SPECT) is often combined with 'simultaneous' low-dose CT (LDCT) to provide complementary anatomical and functional correlation. As a consequence, numerous incidental and unexpected findings may be detected on LDCT. Recognition of these findings and appropriate determination of their relevance can add to the utility of SPECT/CT.

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Objective: The present study compared the outcomes between conventional surgery and the hybrid approach of proximal surgery with adjunctive retrograde descending aortic endografting plus distal bare metal stenting in acute DeBakey type I dissection.

Methods: From 2003 to 2011, 61 patients underwent surgical management for acute type A aortic dissection at our institution. Of these, 37 were DeBakey type I dissections: 18 patients (group 1) received conventional surgical repair alone, and 19 (group 2) underwent conventional hybrid surgery with adjunctive retrograde descending aortic stent grafting plus distal bare metal stenting.

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Objectives: The present study compared the outcomes between combined proximal descending aortic endografting plus distal bare metal stenting and conventional proximal descending aortic stent-graft repair in patients with type A and type B aortic dissection.

Methods: From January 2003 to December 2010, 63 patients underwent endovascular treatment for acute (type A, 24; type B, 21) and chronic (type B, 18) aortic dissection. Of these, 40 patients underwent proximal descending aortic endografting plus distal bare metal stenting (group 1), and 23 underwent proximal descending stent-graft repair alone (group 2).

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Primary central nervous system lymphoma (PCNSL) is an uncommon but important variant of non-Hodgkin lymphoma and represents up to 6% of all primary central nervous system (CNS) malignancies. Recognition of this entity by radiologist on MRI may avoid unnecessary neurosurgical resection and redirect to biopsy. The pretreatment MRI of patients with biopsy proven PCNSL from the last 5 years at our institution was reviewed.

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Background: Established endovascular treatments for aortic dissection often result in incomplete aortic repair, potentially leading to late complications involving the distal aorta. To address the problems of incomplete true lumen reconstitution and late aneurysmal change, we report the midterm results of combined proximal endografting with distal true lumen bare-metal stenting (STABLE: Staged Total Aortic and Branch vesseL Endovascular reconstruction) in Stanford type A and B aortic dissection.

Methods: Between January 2003 and January 2010, 31 patients underwent staged total aortic and branch vessel endovascular reconstruction for management of acute (type A, 13; type B, 11) and chronic (type B, 7) aortic dissection.

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Purpose: (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is an important staging procedure in patients with non-small cell lung cancer (NSCLC). We aimed to demonstrate, through a decision tree model and the incorporation of real costs of each component, that routine FDG-PET imaging as a prelude to curative surgery will reduce requirements for routine mediastinoscopy and overall hospital costs.

Methods: A decision tree model comparing routine whole-body FDG-PET imaging to routine staging mediastinoscopy was used, with baseline variables of sensitivity, specificity and prevalence of non-operable and metastatic disease obtained from institutional data and a literature review.

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