Paradoxical embolism: role of imaging in diagnosis and treatment planning.

Paradoxical embolism (PDE) is an uncommon cause of acute arterial occlusion that may have catastrophic sequelae. The possibility of its presence should be considered in all patients with an arterial embolus in the absence of a cardiac or proximal arterial source. Despite advancements in radiologic imaging technology, the use of various complementary modalities is usually necessary to exclude other possibilities from the differential diagnosis and achieve an accurate imaging-based diagnosis of PDE. In current practice, the imaging workup of a patient with symptoms of PDE usually starts with computed tomography (CT) and magnetic resonance (MR) imaging to identify the cause of the symptoms and any thromboembolic complications in target organs (eg, stroke, peripheral arterial occlusion, or visceral organ ischemia). Additional imaging studies with modalities such as peripheral venous Doppler ultrasonography (US), transcranial Doppler US, echocardiography, and CT or MR imaging are required to detect peripheral and central sources of embolism, identify cardiac and/or extracardiac shunts, and determine whether arterial disease is present. To guide radiologists in selecting the optimal modalities for use in various diagnostic settings, the article provides detailed information about the imaging of PDE, with numerous radiologic and pathologic images illustrating the wide variety of features that may accompany and contribute to the pathologic process. The roles of CT and MR imaging in the diagnosis and exclusion of PDE are described, and the use of imaging for planning surgical treatment and interventional procedures is discussed.

Online health communities and the patient-doctor relationship: An institutional logics perspective.

Taking an institutional logics perspective, this study investigates how "internet-informed" patients manage tensions between the logic of personal choice and the logic of medical professionalism as they navigate treatment decisions and the patient-doctor relationship. Based on 44 semi-structured interviews with members of an online health community for people with diabetes, this study finds that patients exercise a great deal of agency in evaluating healthcare options not only by activating the logic of personal choice but also by appropriating the logic of medical professionalism. Furthermore, patients are strategic in deciding what community advice to share with their doctor or nurse depending on the healthcare professionals' reaction to the logic of personal choice. In contrast to many previous studies that emphasise patient consumerism fuelled by information on the Internet, this study provides a more nuanced picture of patient-doctor relationship engendered by patients' participation in online health communities.