Reduction of Image Artifacts by Bladder Flushing with a Novel Double Lumen Urethral Catheter.

Chad R. Haney, Kazuhiro Ichikawa, Adrian Parasca, Benjamin B. Williams, Eugene D. Barth, Martyna Elas, and Howard J. Halpern,

The University of Chicago, Department of Radiation and Cellular Oncology, MC 1105, 5841 S. Maryland Ave., Chicago, IL 60637-1463

The triarylmethyl spin probe (OX063) developed by Nycomed Inovations (Malmo, Sweden) is useful as a narrow spin probe for in vivo imaging.  However, the accumulation of spin probe in the bladder creates a tremendous source of signal, often greater than that of the tumor due to self broadening, not the broadening by oxygen (the desired measurement).  Due to the paucity of methods available for a non-invasive, MRI/EPRI friendly procedure for flushing a mouse bladder, a novel double lumen urethral catheter was developed.  Using a standard 20 gauge IV catheter (1.1 mm ID, Introcan Safety IV Catheter, B. Braun Medical Inc., Bethlehem, PA) with a rubber tube extension, PE10 tubing (0.28 mm ID, 0.61 mm OD, Clay Adams INTRAMEDIC Polyethylene, BD Franklin Lakes, NJ) was threaded into the IV catheter and the PE10 was stretched such that it is able to curl within the bladder.  Using a Harvard 22 syringe pump, (Harvard Apparatus, Inc., Holliston, MA), water at 15 mL/hr was infused into the bladder via the PE10 tubing.  The effluent from the bladder exits the 20 gauge catheter.  Further refinement maybe necessary, e.g. the placement of the catheter such that it does not get impinged against the wall of the bladder is critical.  However, the double lumen urethral catheter provides a substantial reduction in artifacts when compared to images taken without bladder flushing.  The artifacts generated by the large bladder signal are demonstrated using phantoms.  The reduction of bladder signal artifacts are shown in vivo using mice with PC3 tumors.

This work was supported by grants P41RR12257 (NIH) and DAMD17-02-1-0034 (DOD).

EPR Symposia

Poster session

Chad R. Haney, The University of Chicago, Department of Radiation and Cellular Oncology, MC 1105, 5841 S. Maryland Ave., Chicago, IL 60637-1463, phone (773) 834-5405, fax (773) 702-5940, chaney@uchicago.edu