A catheter tracking method using reverse polarization for MR-guided interventions

To conduct interventional procedures in MRI, reliable visualization of interventional devices such as catheters is necessary. For this purpose, the use of inductively-coupled radio frequency (ICRF) coils has been proposed. Without a wired connection, the signal around the ICRF coil is amplified, enabling catheters to be visualized. The wireless connection allows easy handling of catheters, in some pulse sequences, however, it might be difficult to differentiate the catheters from anatomical background information. In this work, a novel ICRF coil visualization method, which allows separation of the catheter and the anatomical information by using the reverse and forward polarization modes of a coil, is proposed. This method allows images of the anatomy and the catheter to be combined into a color-coded image. First, an ICRF coil with decoupling diodes was constructed; we call this a receive-coupled RF (RCRF) coil. The RF safety profile of the RCRF coil is shown to be better than the ICRF coil. Second, to demonstrate the feasibility of this method, a receive-only birdcage coil without a hybrid coupler was constructed and then connected to a scanner as a two-channel phased-array coil. MR signals acquired from two channels were added after phase adjustments to create the reverse and forward polarization mode images. The reverse polarization mode image contained signal only from the RCRF coil, but the forward polarization mode displayed both anatomical information and the RCRF coil. The performance of this novel tracking method was tested in phantom and animal experiments. Color-coded images demonstrate the feasibility of the method to track catheters using RCRF coils. © 2007 Wiley-Liss, Inc

First record of Epigonus constanciae (Giglioli, 1880), (deepwater cardinalfish) (Osteichthyes: Epigonidae), from Aegean Sea, Turkey

Background. Five specimens of Epigonus constanciae (Giglioli, 1880) (deepwater cardinalfish) were captured first time during a bottom trawl survey in Sigacik Bay and off Karaburun, Aegean Sea. This is the first record of the species from the Aegean Sea. A short description certain of morphometric and meristic features of specimens are given

Surgical Management of a Bilateral Bifid Condyle: Diagnosis, Three-dimensional Reconstruction, and Treatment - A Report of a Case and Review of the Literature.

Bifid condyle is a rare entity with a difficult diagnosis and usually identified as an incidental finding on routine radiographic examination. The etiology is not well known, possible causes may be developmental, traumatic, vascular, abnormal muscle pulling, nutritional, endocrinal, teratogenic, and infections. The orientation of the condylar heads can behelpful for the etiological diagnosis.This case report describes a 56-year-old woman who suffered from a unilateral, progressively increasing, radiating pain which intensified with the movement of the mandible and includes information about the diagnosis, management, radiographic and three-dimensional model features and review of the literature

New records of Bregmaceros atlanticus (Bregmacerotidae), Echiodon dentatus (Carapidae), and Nemichthys scolopaceus (Nemichthyidae) from the Aegean Sea

Background. Three fish species, Bregmaceros atlanticus Goode et Bean, 1886 (Bregmacerotidae), Echiodon dentatus (Cuvier, 1829) (Carapidae), and Nemichthys scolopaceus Richardson, 1848 (Nemichthyidae) were recorded in the Sığacık and Kuşadası Bays (Eastern Aegean Sea, Turkey). B. atlanticus and E. dentatus constitute new records for the Turkish waters and the Aegean Sea, respectively. The finding of Nemichthys scolopaceus is the second record for the Aegean Sea