Thermal effect of intravascular MR imaging using an MR imaging-guidewire: an in vivo laboratory and histopathological evaluation.

Abstract

BACKGROUND:

Intravascular magnetic resonance (MR) imaging to guide interventional procedures is a rapidly growing field. A primary concern with these new techniques is their thermal safety. The purpose of this study was to evaluate, in vivo, the thermal effect of an MR imaging-guidewire (MRIG) for intravascular MR imaging (IVMRI).

MATERIAL/METHODS:

Two indications of potentially adverse local heating were investigated: blood coagulation disorders and pathologic changes in target vessels. Experiments were performed on ten rabbits with a 1.5 T MR scanner. Using a 0.64-mm MRIG as the RF receiver, we imaged the target aorta using a fast spin-echo pulse sequence with an average specific absorption rate (SAR) of 0.6 W/kg. The total MR imaging time was approximately 70 minutes.

RESULTS:

There were no abnormal value changes of the coagulation factors between pre- and post-IVMRI, no clinical manifestations of blood coagulation disorders, and, histopathologically, no thermal damage in target vessels.

CONCLUSIONS:

This study demonstrates, from a pathophysiological point of view, the potential safe use of the MR imaging-guidewire for intravascular MR imaging. Further study is required to precisely define the boundaries of these safe operating parameters.

• Authors: Xiaoming Yang, Christopher J Yeung, Hongxiu Ji, Jean-Michel Serfaty, Ergin Atalar
• Journal: Medical science monitor : international medical journal of experimental and clinical research (Med Sci Monit) Vol. 8 Issue 7 Pg. MT113-7 (Jul 2002) ISSN: 1234-1010 [Print] United States
• PMID: 12118208 (Publication Type: Evaluation Study, Journal Article, Research Support, U.S. Gov't, P.H.S.)

Topics

• Animals
• Aorta, Abdominal (pathology)
• Blood Coagulation Disorders (metabolism, pathology)
• Hot Temperature (adverse effects)
• Humans
• Magnetic Resonance Imaging (adverse effects, methods)
• Rabbits
• Radio Waves (adverse effects)
• Surgery, Computer-Assisted (methods)