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.
Department of Radiology, University of Minnesota Medical School, Minneapolis 55455, USA.
S O
SO
Casey
D
D
Rubinstein
K O
KO
Lillehei
R A
RA
Alberico
R R
RR
Ozsvath
A G
AG
Cajade-Law
B E
BE
Weprin
E
E
Michel
C L
CL
Truwit
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*