Skip to Content

Orhan Unal Ph.D.

Orhan Unal Ph.D.

Senior Scientist

Department Affiliations

Medical Physics

Radiology

Education

B.S., Ankara University, Ankara, Turkey (Physics)

M.S., University of Wisconsin, Madison, WI (Physics)

Ph.D., University of Wisconsin, Madison, WI (Physics)

Research Interest: Interventional MRI, Cardiac Imaging, and Kidney Functional Imaging

My primary research interest is in interventional Magnetic Resonance Imaging (iMRI), in particular developing novel MRI-trackable and visible therapeutic intravascular devices and ultrafast device tracking and imaging techniques for MRI-guided Interventions. Our goal is to develop and extend the capabilities of magnetic resonance imaging (MRI) as a tool for the guidance of minimally invasive endovascular procedures.

MRI-guided interventional procedures offer unique opportunities as well as challanges. Endovascular therapy refers to a general class of minimally invasive interventional techniques that allow treatment of a variety of abnormalities by accessing and treating diseases from within the vasculature. A catheter with the help of a guidewire is manipulated under fluoroscopic image guidance to the area of interest to deploy stents, coils, embolic agents, or drugs through the catheter. Currently, the device or agent delivery is performed under X-ray fluoroscopic guidance. Conventional X-ray fluoroscopy provides high spatial and temporal resolution but requires iodinated contrast material and ionizing radiation. MRI on the other hand offers several advantages over X-ray, including excellent soft-tissue contrast and 3D multiplanar imaging capability. The use of MRI for image-guided therapy (or interventional MRI) has, however, developed more slowly due to limitations of temporal and spatial resolution. Recent advances in MRI acquisition hardware and software, real-time image reconstruction and visualization, and devices will help extend the capabilities of MRI as a guidance tool so that wholly MRI-guided minimally invasive endovascular procedures can be performed.

I've a few projects currently underway. One of my research projects, which was recently funded for $1.5 Million by the National Institutes of Health (NIH), is on developing MRI-guided RF Ablation treatment platform for Atrial Fibrillation. I'm looking for 1-2 motivated graduate students who have the right combination of physics/engineering background, some programming skills and RF hardware experience that would fit well my research program in interventional and who want to work towards a PhD degree in Medical Physics/BME/ECE.

Positions

  • 1985-1986, Teaching Assistant, Department of Physics, Ankara University, Ankara, Turkey

  • 1989-1991, Faculty Assistant, Department of Physics, University of Wisconsin, Madison, WI

  • 1991-1995, Research Assistant, Department of Physics, University of Wisconsin, Madison, WI

  • 1995-1996, Teaching Assistant, Departments of Medical Physics and Radiology, University of Wisconsin, Madison, WI

  • 1996-1998, Postdoctoral Fellow, Departments of Medical Physics and Radiology, University of Wisconsin, Madison, WI

  • 1998-2002, Assistant Scientist, Departments of Medical Physics and Radiology, University of Wisconsin, Madison, WI

  • 2002-2007, Associate Scientist, Departments of Medical Physics and Radiology, University of Wisconsin, Madison, WI

  • 2008-present, Senior Scientist, Departments of Medical Physics and Radiology, University of Wisconsin, Madison, WI

  • 2008-present, Director of Medical Physics Computing

Awards and Honors

  • 1998 Symposium Neuroradiologicum XVI Paper/Poster Award of Excellence

  • 1998 International Society for Magnetic Resonance in Medicine Stipend

  • 1999 International Society for Magnetic Resonance in Medicine Stipend

Memberships

  • 1996-present International Society for Magnetic Resonance Imaging

  • 1999-present American Association of Physicists in Medicine

Patents

  • MR Signal-Emitting Coatings. Frayne R, Strother CM, Unal O, Yang Z, Wehelie A, Yu H. 6361759, 2002.

  • Improved Magnetic Resonance Signal Emitting Coatings for Devices Used in Therapeutic MRI Applications. Li J, Unal O, Jiang X, Strother CM, Yu H, 6896874, 2005.

  • MRI Method for Assessing Myocardial Viability. Unal O, Grist TM, US patent application (P04057US), 2003.

  • Refined Process for Coating Medical Devices with a MR Signal-Emitting Polymer. Unal O, Li J, Strother CM, Yu H, US patent application, 2004.

  • Multi-layer MR-visible Coatings. Cheng W, Li J, Unal O, Strother CM, Yu H, US patent application, 2005.

  • Multi-mode Tracking and Imaging Probes for MR-guided Interventions. Unal O, Kurpad K, US patent application (P05330US), 2006.

  • Hyrid Trackable and MR-visible Interventional Devices. Unal O, Kurpad K, US patent application (P0441US), 2006.

  • MR-guided Simultaneous Device Tracking and Imaging. Unal O, Brodsky E, Kurpad K, US patent application (P06222US), 2006.

  • Multi-mode Tracking, Imaging, and Thermal Ablation Probes for MR-guided Interventions. Unal O, Kurpad K, C. Brace, US patent application (P06225US), 2007.

  • HYPR Catheter Tracking and Visualization. Mistretta CA, Unal O, US patent application, 2007.

  • Improved RF safety of Intravascular MR Probes. Unal O, Kurpad K, US patent application (P07141US), 2007.

  • Improved Multi-mode MR Probes. Kurpad K, Unal O, US patent application (P07234US), 2007.

Selected peer-reviewed publications

  • Unal O, F. R. Korosec, R. Frayne, C. M. Strother, C. A. Mistretta, A Rapid 2D Time-Resolved Variable-Rate K-space Sampling MR Technique for Passive Catheter Tracking During Endovascular Procedures. Magn. Reson. Med. 40, 356 (1998).
  • Unal O, R. Frayne, C. M. Strother, F. R. Korosec, C. A. Mistretta, 2D Time-Resolved MR Technique for Catheter Visualization During Endovascular Procedures at 1.5 T Rivista Di Neuroradiologica. 11, 113 (1998).
  • R. A. Omary, R. Frayne, Unal O, T. M. Grist, C. M. Strother, Intra-arterial Gadolinium-enhanced 2D and 3D Magnetic Resonance Angiography: A Preliminary Study. JVIR 10, 1315 (1999).
  • A. M. Masaryk, R. Frayne, Unal O, C. A. Mistretta, C. M. Strother, In vitro and in vivo Comparison of Three Methods for MR Measurement of Vascular Shear Stress in the Internal Carotid Artery. AJNR 20, 237 (1999).
  • A. M. Masaryk, R. Frayne, Unal O, C. A. Mistretta, C. M. Strother, Utility of CT Angiography and MR Angiography for the Follow-up of Experimental Aneurysms Treated with Stents and Guglielmi Detachable Coils. AJNR 21, 1523 (2000).
  • R. Frayne, R. A. Omary, Unal O, C. M. Strother, Determination of Optimal Injection Protocols for Intra-arterial Gadolinium-enhanced MR Angiography: A Preliminary Study. JVIR 11, 1277 (2000).
  • R. A. Omary, R. Frayne, Unal O, F. R. Korosec, C. A. Mistretta, C. M. Strother, T. M. Grist, MR -Guided Angioplasty of Renal Artery Stenosis in a Pig Model: A Feasibility Study. JVIR 11, 373 (2000).
  • C. M. Strother, Unal O, R. Frayne, A. S. Turk, R. A. Omary, F. R. Korosec, C. A. Mistretta, Feasibility of the Endovascular Treatment of Experimental Canine Aneurysms using MR Guidance. Radiology. 215, 516 (2000).
  • R. A. Omary, Unal O, D. S. Koscielski, R. Frayne, F. R. Korosec, C. A. Mistretta, C. M. Strother, T. M. Grist, Real-Time MR Imaging-guided Passive Catheter Tracking with Used of Gadolinium-filled Catheters. JVIR 11, 1079 (2000).
  • X. Q. Jiang, H. Yu, R. Frayne, Unal O, C. M. Strother, Novel Magnetic Resonance Signal Enhancing Coating Material. Advanced Materials 13, 490 (2001).
  • W. D. D'Souza, E. L. Madsen, Unal O, K. K. Vigen, G. R. Frank, B. R. Thomadsen, Tissue Mimicking Materials for a Multi-Imaging Modality Prostate Phantom. Medical Physics 28, 688 (2001).
  • R. A. Omary, K. P. Henseler, Unal O, R. J. Smith, R. K. Ryu, S. A. Resnick, M. B. Saker, H. B. Chrisman, R. Frayne, J. P. Finn, D. B. Li, T. M. Grist, Validation of Injection Parameters for Catheter-directed Intraarterial Gadolinium-enhanced MR Angiography. Acad Rad 9, 172 (2002).
  • X. Q. Jiang, H. Yu, R. Frayne, Unal O, C. M. Strother, Surface Functionalization of Polyethylene for Magnetic Resonance Signal-Enhancing Coating Materials. Chem. Mater. 14, 1914 (2002).
  • R. A. Omary, K. P. Henseler, Unal O, L. J. Maciolek, J. P. Finn, D. B. Li, A. A. Nemcek, R. L. Vogelzang, T. M. Grist, Comparison of Intraarterial and IV Gadolinium-enhanced Magnetic Resonance Angiography with Digital Subtraction Angiography for the Detection of Renal Artery Stenosis in Pigs. AJR 178, 119 (2002).
  • S. K. Alford, E. A. Sadowski, Unal O, J. A. Polzin, D. W. Consigny, F. R. Korosec, T. M. Grist, Detection of Renal Ischemia in Swine Using Blood Oxygen Level-Dependent Magnetic Resonance Imaging. JMRI 22, 347 (2005).
  • Unal O, J. Li, W. Cheng, H. Yu, C. M. Strother, MR-Visible Coatings for Endovascular Device Visualization. JMRI 23, 763 (2006).
  • K. Kurpad and Unal O, Multi-mode Intravascular RF Coil for MRI-Guided Interventions. JMRI 33, 995 (2011).
  • S. Kecskemeti, Johnson K, Francois C, Schiebler M, and Unal O, Volumetric Late Gadolinium-Enhanced Myocardial Imaging with Retrospective Inversion Time Selection. JMRI 38, 1276 (2013).
  • P. Wang and Unal O, Motion-compensated Real-time MR Thermometry Augmented by Tracking Coils. JMRI 41, 851 (2015).


Copyright © 2011 The Board of Regents of the University of Wisconsin System