Abstract: A device for locating radiopharmaceutical labeled diseased or malfunctioning candidate cells within a human body and a method for using the device. The method includes the labeling of target cells in a body with a radionuclide and the identification in situ of the candidate cells using a body insertable nuclear probe sensitive to the presence of the radionuclide label. More particularly, the invention relates to using a beta or gamma probe to locate labeled cells, also referred to as candidate cells while simultaneously generating an MRI image and/or a visual image. The device may also include attachments to the distal tip if the probe which allows the position of the tip within the body to be tracked and recorded or the aperture to be varied in size.