Seung Hoon Ha1, Mark J. Hamamura1, Werner W. Roeck1, Orhan Nalcioglu1, Douglass J. Wagenaar2, Dirk Meier2, Bradley E. Patt2
1Center for Functional Onco-Imaging, University of California, Irvine, CA, USA; 2Gamma Medica-Ideas, Inc., Northridge, CA, USA
The effect of nuclear collimators made of lead (Pb) on MR imaging was investigated using a dedicated dual modality RF coil built for small animal imaging. The intro-duction of the collimator affected both the SNR as well as MR image uniformity. The signal non-uniformity was reduced considerably by the introduction of additional lead shielding around the object at the expense of reducing the image SNR. In spite of this minor shortcoming the effect of Pb collimator on the MR image was reduced considerably that should make it useful for dual modality MR nuclear imaging such as MR - SPECT and MR - PET. Additionally since the imaging time for nuclear images is much longer than MRI one can easily increase the number of averages in the MRI to overcome this problem.