TRIMMING NON_CRAN ROI'S 01. select the image on which to trim non_cran roi's 02. type "g mrqid" in the unix shell 03. cd to the 10_ACPC dir 04. type "ls" 05. check to see that "mrqid_stereo.img" exists in that 10_ACPC dir 06. begin checking the user directories ???????????? in search of the non_cran.zroi's ie: cd to the user (login name) dir and type ls 07. if the non_cran.zroi's are in someone else's dir, you must copy them to your user dir 08. to copy non_cran.zroi's: a. in the 10_ACPC dir type "mkdir login name" b. cd to that new dir (ie: cd helen) c. type "cp full path to the 10_ACPC/tracer/*non_cran* full path to the 10_ACPC/login name d. now these traces are in your directory e. e-mail the original tracer instructing them to remove the traces from their directory 09. start brains 10. load menu- image 11. load stereo.img 12. load menu- image 13. load t1 image 14. load menu- image 15. load pd/t2 image 16. zoom in @ f2 on the coronal 17. set front# to "1" 18. use your right mouse button to set foreground roi to non_cran (this will cause the trace to turn red) Note: This step is different from previos steps in that it does not follow a series of step by step instructions. Instead it uses general rules of thumb that allow us to edit our non_cran roi's. 19. page forward until you see brain (& surface csf) 20. you should see the hemispheres which are small at first as you go forward, they enlarge and the cerebellum emerges 21. the net has already traced the brain, the point here is to edit any gross mistakes (>4 pixels) 22. if an area is questionable as to whether or not it is brain or surface csf, page forward to see whether it develops into brain or not; be sure to use the other modalities for clarification 23. if you see an area that either mistakenly excludes brain and/or surface csf or includes non-brain material, edit it 24. to edit: a. use the right mouse key; choose edit foreground roi b. use the left mouse key to click in close proximity to the left of the area you want to edit c. use the left mouse key to click w/in the area to be editted d. use the left mouse key to click in close proximity to the right of the area you want to edit e. hold the left mouse key down and retrace the editted area from right to left f. be sure to edit the smallest area of the original trace as possible!!! Note: all tracing is done on the stereo image; the other modalities are only used to aid in the idnetification of certain areas and structures 25. when the vertebral artery comes into view, align the crosshares in the middle of the most superior artery (ref: Yuh et al. MRI of Head & Neck Anatomy pg 145-146) 26. as you page forward, the artery will move; be sure to move the cross- hares, keeping them in the middle of the artery as it moves 27. the horizontal line from the crosshares is now used as the cut off point for the inferior boarder of our trace 28. exclude brain stem and cord below the horizontal cross-hare guideline 29. include the cisterna magna in the traces (ref: Yuh et al. MRI of Head & Neck Anatomy pg 122) 30. once you see the permanent seperation of white matter in the cord, discontinue using the horizontal guide line as the inferior boarder (ref: Yuh et al. MRI of Head & Neck Anatomy pg 115) 31. the new inferior boarder should include only the pons, medulla oblongata, and surrounding csf 32. when editting the superior and lateral boarders of the brain, be sure dura mater is excluded from this trace 33. eventually the pons will appear to break away from the rest of the brain (ref: Yuh et al. MRI of Head & Neck Anatomy pg 110) 34. the inferior boarder of the trace should hug the temporal lobes, removing the pools of csf, and boardering the inferior of the sphenoid sinus 35. don't allow the trace to dip down into the eyeballs 36. make sure every slice of brain and surface csf is included in the trace 37. quit brains