fig1 is a schematic diagram showing a patient &# 39 ; s body part 1 including a gamma radiant tracer material 2 within a region of interest , wherein a gamma camera 3 captures data from the patient &# 39 ; s body part 1 . first , second , third and fourth tracking arrays ( e . g ., arrays of reflective spheres ) 4 , 6 , 10 and 15 are coupled to the gamma camera 3 , a first instrument 5 , a second instrument 9 , and the patient &# 39 ; s body part 1 , respectively . the first instrument 5 includes a flexible tip section 7 having a tracer material 8 on the tip section 7 . the second instrument 9 is a rigid instrument such as a scalpel , for example . an infrared tracking system 11 includes first and second stereoscopic infrared tracking cameras 12 and 13 , each coupled to a camera holder 11 a . an infrared light source 14 is coupled to the camera holder 11 a . a navigation system 20 , which includes a display 21 , is operatively coupled to the infrared tracking system 11 and gamma camera 3 via lines 22 and 23 , respectively . gamma camera 3 , instrument 5 and scalpel 9 can be tracked by the infrared tracking system 11 and navigated by navigation system 20 as disclosed in de 196 39 615 c2 , for example . injection of radioactive tracer material 2 into the patient 1 typically takes place approximately 45 minutes to 24 hours prior to surgery . the photons within the region of interest are reflected back to the camera 3 by use of this radioactive tracer material 2 . the amount of photons is not large enough to negatively affect the medical team participating in the procedure , although protection through the use of lead vests and protective glasses may be utilized . reflective arrays 4 and 15 are positioned in the pre - calibrated gamma camera 3 and patient body part 1 via universal adapters , for example . diagnostic images can be loaded into the navigation system 20 , and the patient can be registered using known methods . the spatial relationships between instruments 5 and 9 , gamma camera 3 , and patient 1 are coordinated via the navigation system 20 through the arrays 4 , 6 , 10 , 15 and displayed on the navigation display 21 . since the pre - calibrated gamma camera 3 is tracked , i . e ., localized by tracking system 11 through reflective array 4 , the content of the images obtained by the camera also can be positionally assigned , and those images can supplement the diagnostic image information previously obtained ( e . g ., from previously obtained images of the patient and / or patient body part via other imaging modalities ) and loaded into the navigation system 20 . the gamma camera images can be obtained in real time , and surgeons can view anatomical regions and shapes and are able to identify abnormalities as they appear within the body intraoperatively . additionally , the surgeon can view surgical instruments 5 and 9 approaching and / or acting on tissue , and verify complete resection . with respect to the instrument 5 that includes the flexible tip section 7 , the infrared tracking system may not be able to provide exact information about the tip &# 39 ; s location in the body portion 1 . to make up for this lack of information , instrument 5 is equipped with tracer material 8 at its tip section 7 and , thus , the tip section 7 can be localized by the gamma camera 3 and correctly represented by the navigation system . although the invention has been shown and described with respect to a certain preferred embodiment or embodiments , it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings . in particular regard to the various functions performed by the above described elements ( components , assemblies , devices , compositions , etc . ), the terms ( including a reference to a “ means ”) used to describe such elements are intended to correspond , unless otherwise indicated , to any element which performs the specified function of the described element ( i . e ., that is functionally equivalent ), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention . in addition , while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments , such feature may be combined with one or more other features of the other embodiments , as may be desired and advantageous for any given or particular application .
a medical tracking system includes a localization system operative to spatially localize medical instruments ; a computer operative to assign absolute and / or relative positions of said instruments in a coordinate system ; and at least one localizable gamma camera operative to detect gamma radiation emitted from a tracer material .