c-TCCS is a sensitive noninvasive method for detecting cardiac right-to-left shunt and is as sensitive as c-TEE.

Objective Paradoxical embolization by cardiac right‐to‐left shunts (RLS) is increasingly recognized as an important factor for embolic stroke. Contrast‐enhanced transcranial Doppler sonography (ce‐TCDS) is an established diagnostic tool for RLS detection but is frequently limited because of an inadequate temporal acoustic bone window. The purpose of this study was to determine whether extracranial sonography (ECS) using harmonic frequencies improves detection of RLS. Methods Extracranial color duplex sonography using harmonic frequencies enables visualization of even single ultrasound contrast agent microbubbles because of oscillation. Patients with stroke and positive RLS findings on transesophageal echocardiography underwent a simultaneous extracranial and transcranial sonographic examination of the proximal common carotid artery (CCA) and middle cerebral artery (MCA) on the same side. A Valsalva strain was performed for 10 seconds after intravenous bolus injection of a galactose‐based nontranspulmonary contrast agent. The B‐mode frame sequences of the transverse plane of the CCA obtained by harmonic ECS and the ce‐TCDS recordings of high‐intensity transient signals from the MCA were analyzed offline. Results In all patients with RLS, the shunts could be identified by harmonic ECS. A close correlation could be seen between the count of visualized microbubbles in the CCA and the number of high‐intensity transient signals detected on ce‐TCDS in the ipsilateral MCA. Conclusions The results of this study indicate that contrast‐enhanced ultrasound harmonic imaging of the CCA using a Valsalva strain might be an optional screening tool for detection of cardiac RLS in patients with insufficient acoustic bone windows.

Dynamic and three-dimensional transcranial sonography (dTCS and 3D-TCCS) examinations are complementary, noninvasive methods used in the assessment and follow up of patients with cerebrospinal fluid (CSF) circulation disorders.A 16-year-old female patient who presented with a space-occupying, cerebral convexity arachnoid cyst and recurrent tension-type headache underwent examination for raised intracranial pressure (ICP) by using a standard color-coded duplex sonography system attached to a personal computer--based system for 3D data acquisition. Conventional TCS identified the outer arachnoid membrane of the cyst, which undulated freely after short rotation of the head ("headshake maneuver"). The undulation was documented as a QuickTime movie that is included with this article. A 3D dataset was acquired and, by using a multiplanar reformatting reconstruction algorithm, the authors obtained images with excellent resolution that corresponded to an initial magnetic resonance (MR) imaging study. No differences on dTCS and 3D-TCS were detectable at follow up 9 months later, indicating normal ICP and a stable, benign condition.The use of 3D-TCCS and dTCS ultrasonography may complement other diagnostic procedures such as MR imaging and, thus, can improve management and therapeutic strategies for patients with CSF circulation disorders. In this report the authors present evidence of the excellent fine resolution and exact reproducibility of reconstructed ultrasound image planes derived from 3D datasets and the additional biomedical information from dynamic imaging.