Paradoxical Embolism: Role of Imaging in Diagnosis and Treatment Planning

Abstract

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.

The imaging features of neurologic complications of left atrial myxomas

“…Traumatic aneurysms, resulting from direct penetrating head injuries or blunt head trauma, may be associated with other traumatic lesions [32]. Another cardiac condition also leading to a similar pattern of brain infarcts is patent foramen ovale (PFO), by means of paradoxical emboli through abnormal intracardiac or intrapulmonary communication between the right and left circulations [33]. The difference is that there is no apparent cardiac source on the left side of the heart or in the proximal arterial tree (ascending aorta) in PFO.…”

Challenging Cases in Cerebrovascular Disease

“…22 TTE is a noninvasive, accurate, and inexpensive imaging modality for the evaluation of PFO. 23 The sensitivity of TTE is 88% and its specificity is 97% for the detection of PFO. 24 TEE has as similar sensitivity (89%) and slightly lower specificity (91%).…”

“…TTE is a non-invasive, accurate and inexpensive imaging modality for evaluation of PFO 23 . The sensitivity of TTE is 88% and its specificity is 97% for the detection of PFO 24 .…”

Radiopaque Fiducials Guiding Laparoscopic Resection of Liver Tumors

“…However, the inadvertent migration of one rod to the lung raised concerns of possible paradoxical arterial embolization and prompted yet another amendment to our protocol, preoperative ultrasonography of the heart to exclude transseptal shunting. 10 The method has shortcomings. Preparations increase total procedure times.…”

“…The adoption of dedicated gold rod markers also facilitated fiducial placement. However, the inadvertent migration of one rod to the lung raised concerns of possible paradoxical arterial embolization and prompted yet another amendment to our protocol, preoperative ultrasonography of the heart to exclude transseptal shunting 10…”