Show pageBacklinksCite current pageExport to PDFBack to top This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ====== Image-guided stereotactic surgery ====== {{rss>https://pubmed.ncbi.nlm.nih.gov/rss/search/10iSX9Fqs0DGh8DYA1yUth79sikVijpsuBn4xLs3eCVUnLz9gH/?limit=15&utm_campaign=pubmed-2&fc=20240202102518}} A method in neurosurgery for locating points within the brain using an external, three-dimensional frame of reference usually based on the [[Cartesian coordinate system]]. ---- The term [[stereotactic]] (Greek: stereo = 3-dimensional, tactic = to touch) surgery was initially used in [[animal]]s, and was based on [[atlas]]es of three-dimensional coordinates compiled from [[dissection]]s. The term was then used for surgery performed in humans, usually for [[thalamic]] lesioning to treat [[Parkinsonism]]. The [[technique]]s of [[stereotactic surgery]] are utilized in some functional procedures (e.g. [[DBS]]) as well as for biopsies (see [[Stereotactic biopsy]]) [[cyst]] drainage, etc. The term [[stereotactic]] (Greek: stereo = 3-dimensional, tactic = to touch) surgery was initially used in animals, and was based on atlases of three-dimensional coordinates compiled from dissections. The term was then used for surgery performed in humans, usually for [[thalamic]] lesioning to treat [[Parkinsonism]], see [[Parkinson's disease surgery]], where the target site to be lesioned was located relative to [[landmark]]s with intraoperative [[pneumoencephalography]] or contrast [[ventriculography]]. Use of this procedure fell off dramatically in the late [[1960]]s with the introduction of [[L-dopa]] for [[Parkinsonism]] ((Gildenberg PL. Whatever Happened to Stereotactic Surgery? Neurosurgery. 1987; 20:983–987)) ===== Indications ===== see [[Stereotactic surgery indications]]. For image-guided [[stereotactic surgery]], in the first part of the procedure, a [[CT]] scan or [[MRI]] (or occasionally, [[angiogram]]) is performed. For increased precision, “[[fiducial]]” markers or a [[stereotactic frame]] is attached to the patient’s head during this image acquisition phase. Acceptable accuracy for [[biopsy]] can often be obtained using high resolution thin cut imaging slices (usually with a 0 angle of the [[gantry]]), and then surface matching algorithms in the guidance system will match the pre-op CT/MRI to the patient’s head. This is not accurate enough for lesion generation or [[electrode placement]]. The second part of the procedure usually takes place in an [[operating room]]. The patient is “registered” with the pre-op images, and then tracking cameras follow the movement of instruments with appropriate attachments to show in “real-time” the location of the instrument with respect to the pre-op image. An important limitation to be aware of is the fact that the pre-op images are “historical” and are not updated as the surgical procedure alters the anatomy of the patient. Even the administration of [[mannitol]] can cause brain shifts that may cause the target of the surgery to move away from its pre-op location by several millimeters ((Bucholz RD, Yeh DD, Trobaugh J, et al. The correction of stereotactic inaccuracy caused by brain shift using an intraoperative ultrasound device. In: Lecture Notes in Computer Science. Berlin: Springer; 1997. DOI: 10.1007/BFb0029268)). image-guided_stereotactic_surgery.txt Last modified: 2024/06/07 02:55by 127.0.0.1