COMBINED ULTRASOUND-RADIONUCLIDE DEVICE FOR PERCUTANEOUS ULTRASOUND-GUIDED BIOPSY AND METHOD OF USE

A system and apparatus is disclosed for providing percutaneous images to assist in performing an accurate tissue biopsy and to locate nuclear medicine tracer uptake within a living being. The invention provides superimposed, simultaneous ultrasound and nuclear activity images to assist in performing accurate tissue biopsy for any procedure in which nuclear activity is used to localize possible pathological tissue. The apparatus includes a medical instrument having at least a pair of radionuclide detectors capable of detecting the depth of tracer uptake within a region of interest, which can include locating the sentinel lymph node in a breast cancer patient. The radionuclide detector is coupled to, and in operable association with, an ultrasound probe for percutaneous detection of anatomical structure about the area of maximum tracer uptake. The radionuclide detectors and the ultrasound probe are pivotally connected. The depth of the maximum tracer uptake can be determined by pivotally moving the radionuclide detectors to vary a focal point which is formed by the intersection of a line of sight from each radionuclide detector. The focal point is adjusted to the area of maximum tracer uptake by use of a visual display of radioactivity count rate or an auditory output of the radioactivity count rate. After the depth is determined and mapped, an ultrasound image is produced of the localized area. The system produces an image in which the ultrasound image is superimposed with a color representation of the tracer uptake to assist a radiologist or a surgeon in performing a tissue biopsy while avoiding vital structure.