Integral and shell-MIP display algorithms in MR and CT three-dimensional models of the brain surface.
OBJECTIVE
Our purpose was to demonstrate the use of integral and shell maximum intensity projection (shell-MIP) display algorithms in the 3-D CT and MR depiction of cerebral gyral and surface venous anatomy and disorders. These new algorithms are compared against MIP and shaded-surface-display (SSD) algorithms.


METHODS
Integral and shell-MIP displays were generated from a specified number of proximal surface voxel layers in a 3-D model. Algorithmic models were compared on nine contrast-enhanced spoiled gradient-recalled acquisition in a steady state (SPGR) MR venograms for brain surface anatomic identification and detail. Seven CT venograms were compared for conspicuity of filling defects. Twelve contrast-enhanced preoperative planning 3-D MR models were rated for neurosurgical utility.


RESULTS
A shell-MIP score of 7.00 and an integral score of 6.78 represented the highest mean subjective MR gyral quality (1-10 scale) followed by an SSD score of 3.89 and an MIP score of 1.06. Mean confidence scores for MR central sulcus identification (1-10 scale) were shell-MIP, 7.67; integral, 7.00; SSD, 3.22; and MIP, 1.00. Mean superficial venous quality MR ratings (1-10 scale) were shell-MIP, 8.22; MIP, 7.39; integral, 7.00; and SSD, 3.72. The mean number of cortical veins draining into each side of the superior sagittal sinus on MR was as follows: MIP, 6.19; integral, 6.06; shell-MIP, 5.94; and SSD, 3.81. Mean confidence scores for filling defect identification on CT venograms (1-5 scale) revealed a shell-MIP score of 4.36 and an integral score of 4.29 to be superior to a MIP score of 3.00. In selected cases, 3-D presurgical planning, prior to tumor resection, was clinically useful.


CONCLUSIONS
Integral and shell-MIP are useful 3-D display algorithms for simultaneous display of superficial cerebral veins and gyri on MR images and of thrombosis on CT venograms.
Casey
S O
SO
Department of Radiology, University of Minnesota Medical School, Minneapolis 55455, USA.
Rubinstein
D
D
Lillehei
K O
KO
Alberico
R A
RA
Ozsvath
R R
RR
Cajade-Law
A G
AG
Weprin
B E
BE
Michel
E
E
Truwit
C L
CL
D000465:Algorithms; D001927:Brain Diseases / Q000175:diagnosis / Q000601:surgery; D001932:Brain Neoplasms / Q000175:diagnosis / Q000601:surgery; D002540:Cerebral Cortex / Q000098:blood supply / Q000473:pathology*; D002550:Cerebral Veins / Q000473:pathology*; D003198:Computer Simulation; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D012680:Sensitivity and Specificity; D013813:Therapy, Computer-Assisted / Q000295:instrumentation; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*