Browsing by Subject "Catheterization"

Filter results by typing the first few letters
Now showing 1 - 3 of 3
  • Thumbnail Image
    ItemOpen Access
    Iatrogenic superficial external pudendal artery pseudoaneurysm: Treatment with doppler us-guided compression
    (Tehran University of Medical Sciences (TUMS), 2014) Algin O.; Mustafayev, A.; Ozmen, E.
    Pseudoaneurysms rarely occur as a serious complication following incomplete hemostasis of an arterial puncture site. As a result of the increase in diagnostic and therapeutic angiography, the frequency of iatrogenic pseudoaneurysm has increased as well. Iatrogenic pseudoaneurysms associated with angiographic catheterization occur most commonly in the common femoral artery. Here we report a case of iatrogenic superficial external pudendal artery (SEPA) pseudoaneurysm following cardiac catheterization, which was diagnosed with Doppler ultrasound (US) and multidetector computed tomographic angiography (MDCTA) before Doppler US-guided compression therapy. To the best of our knowledge, iatrogenic SEPA pseudoaneurysm, which is an unusual vessel location for pseudoaneurysm occurrence, has not been reported in the literature. In patients in whom anticoagulant-thrombolytic therapy or therapeutic catheterization with larger sized sheath is planned, determination of the precise localization of arterial puncture site is important for the prevention of iatrogenic pseudoaneurysm development. Arterial puncture guided with Doppler US might reduce complications. When suspected, MDCTA is useful in the diagnosis and demonstration of iatrogenic pseudoaneurysms. Treatment of US-guided compression should be the first choice for iatrogenic pseudoaneurysms. Interventional radiologists and cardiologists should have enough experience about the catheterization complications and their treatment in order to decrease the morbidity and mortality related to the intervention.
  • Thumbnail Image
    ItemOpen Access
    Interactive real-time RF control for MRI transmit channels
    (2019-09) Yılmaz, Uğur
    Cardiac catheterization is one of the heavily researched areas of the real-time interventional studies in Magnetic Resonance Imaging (MRI), where elongated conductive wires are prone to excessive radiofrequency (RF) heating and tracking of the devices might be challenging. Previous studies have proposed several techniques for heating reduction at the conductive wire tip and device visualization, using multiple transmit channels but the software platform for real-time RF control of multiple transmit channels has been missing for interventional procedures. In this study, we are presenting a software framework capable of interactive real-time RF control of MRI transmit channels and reception of dynamic images from MR image reconstruction computer. The software consists of three main programs running on three di erent operating systems (Linux, Windows and VxWorks) that communicate with each other over TCP/IP connection. Besides socket programming, multi-threading/multi-tasking is implemented for each platform along with the synchronization semaphores. The graphical user interface end is developed with Qt. Siemens' work-in-progress tip-tracking pulse sequence (BEAT IRTTT) source code is modi ed to serve as the other end in our software system. The interactive real-time experiments are conducted on a copper sulfate phantom including a conductive wire. Dual-port body coil which is a product of Siemens is used as the transmit antenna and each port is driven independently. Results have shown the feasibility of the real-time RF control in the MRI, with an e ective total update latency of two frames on the dynamic image-series. We believe this framework will contribute to real-time interventional procedures in terms of RF safety and catheter tracking.
  • Thumbnail Image
    ItemOpen Access
    Intravascular extended sensitivity (IVES) MRI antennas
    (John Wiley & Sons, Inc, 2003) Susil, R. C.; Yeung, C. J.; Atalar, Ergin
    The design and application of an intravascular extended sensitivity (IVES) MRI antenna is described. The device is a loopless antenna design that incorporates both an insulating, dielectric coating and a winding of the antenna whip into a helical shape. Because this antenna produces a broad region of high SNR and also allows for imaging near the tip of the device, it is useful for imaging long, luminal structures. To elucidate the design and function of this device, the effects of both insulation and antenna winding were characterized by theoretical and experimental studies. Insulation broadens the longitudinal region over which images can be collected (i.e., along the lumen of a vessel) by increasing the resonant pole length. Antenna winding, conversely, allows for imaging closer to the tip of the antenna by decreasing the resonant pole length. Over a longitudinal region of 20 cm, the IVES imaging antenna described here produces a system SNR of approximately 40,000/r (mL-1Hz1/2), where r is the radial distance from the antenna axis in centimeters. As opposed to microcoil antenna designs, these antennas do not require exact positioning and allow for imaging over broad tissue regions. While focusing on the design of the IVES antenna, this work also serves to enhance our overall understanding of the properties and behavior of the loopless antenna design. © 2003 Wiley-Liss, Inc.