Computer tomography assisted stereotactic surgery system and method

A clinical method in which an internal region of a subject is precisely located in advance of an invasive procedure, the method comprising:

• imaging a volume of the subject at a first location and producing three-dimensional diagnostic mapping data indicative thereof;
• at a second location in which the invasive procedure is to be performed, imaging the subject to generate a two dimensional calibration reference image through a region of interest prior to instituting the invasive procedure, the step of generating a two dimensional calibration reference image including examining the subject with a digital radiographic imaging apparatus such that the two dimensional calibration reference image is a calibration reference shadowgraphic projection image;
• projecting a projection image from the three-dimensional diagnostic mapping data which projection image is analogous to the two dimensional calibration reference image;
• comparing the calibration reference image and the analogous projection image;
• and,
• adjusting spatial position and angular orientation through which the mapping data is projected into the analogous projection image until a selected portion of the analogous projection image most accurately matches a corresponding selected portion of the calibration reference image, whereby the mapping data is brought into at least partial registration with the actual, current position of the subject.

In a clinical procedure wherein an internal region of the subject is subjected to an invasive procedure, precisely locating and mapping said internal region in advance of the procedure comprising the steps of:

• conducting a series of planar scans of the subject and obtaining three-dimensional electronic mapping data indicative of internal structure of at least said internal region of the subject from the scans;
• generating man-readable images from the mapping data and identifying the internal region to be treated by the invasive procedure from the man-readable images;
• selecting a point of entry into the subject and a path through the subject from the man-readable images;
• fixing the position of the subject relative to a clinical station where the invasive procedure is to be performed;
• performing a non-invasive imaging of the patient to produce a first calibration reference image representing a two dimensional shadowgraph of a least a portion of the subject along a first direction which includes said internal region;
• generating analogous shadowgraphic projection image from the three-dimensional electronic mapping data which analogous shadowgraphic projection image represents a projection through the three-dimensional electronic mapping data along a calibration direction that substantially matches the first direction;
• comparing the calibration reference and three-dimensional electronic mapping shadowgraphic images to obtain an indication of the location of said internal region in relation to the clinical station;
• positioning an invasive instrument guide to aim a surgical instrument to enter the subject at the selected point of entry and follow the selected path;
• and,
• producing a second calibration reference image of the guide and the subject to check to guide positioning.

An apparatus for performing an invasive surgical procedure on a subject, the apparatus comprising:

• scanning means for scanning at least a selected region of the subject and generating an electronic mapping data representing a three dimensional region of the subject;
• an image memory means for storing the mapping data;
• a display means for displaying man-readable diagnostic images reconstructed from the mapping data in the image memory, which diagnostic images represent slices through the region of interest;
• an imaging means for generating and storing electronic data representative of a two dimensional reference image through the region of interest, the imaging means being operatively connected with the display means for displaying a man-readable two dimensional reference image from the stored data;
• a reformatting means for reformatting the mapping data from the image memory into a reformatted diagnostic image of the format of the reference image from the imaging means;
• an adjusting means for adjusting spatial position and angular orientation with which the reformatting means reformats the mapping data such that the reformatted image more closely matches the reference image;
• and,
• a surgical instrument positioning means for positioning a surgical instrument relative to the patient to direct the surgical instrument to penetrate the patient at an entrance point selected from the diagnostic images, after generation of the images, and proceed along a path selected from the diagnostic images.