TRIANGULAR SPECT SCANNER AND HIGH-SENSITIVITY, 3-DIMENSIONAL, DYNAMIC RADIONUCLIDE IMAGING

THE OBJECTIVE OF THIS PROPOSAL IS TO DEVELOP A HIGHLY OPTIMIZED SINGLE-PHOTON EMISSION-COMPUTED TOMOGRAPHY (SPECT)SYSTEM FOR 3-DIMENSIONAL (3-D) BRAIN AND TORSO ORGAN IMAGINGWITH DYNAMIC CAPABILITY. THE SPECIFIC AIM IS TO DESIGN, DEVELOP, AND TEST A TRIANGULAR SPECT SCANNER BASED ON THREE RECTANGULAR NAI(T1) GAMMA CAMERAS OF 16-INCH X 9-INCH FOV FOR HIGH-SENSITIVITY SPECT. SENSITIVITY IMPROVEMENT WILL BE450 PERCENT FOR BRAIN BY MATCHED FAN BEAM COLLIMATION, AND 300 PERCENT FOR BODY ORGANS, OVER THE CURRENT SINGLE-HEAD SYSTEMS, AND THE CURRENT 30-MINUTE IMAGING TIME WILL BE REDUCED TO 7 TO 10 MINUTES. ANOTHER MAJOR AIM IS TO DEVELOP3-D MAPPING CAPABILITY OF RCBF BY CONTINUOUS CLOCKWISE (CW) AND COUNTERCLOCKWISE (CCW) ROTATION FOR FULL-PROJECTION DATACOLLECTION IN EACH 120 DEGREES, WITH TIME RESOLUTION DOWN TO5 SECONDS. THIS CAMERA-BASED SYSTEM ALLOWS COLLIMATOR DESIGN FLEXIBILITY FOR RESOLUTION-SENSITIVITY TRADE-OFF. FOR THE BRAIN, THREE DETECTORS MAKE A TIGHT TRIANGLE WITH 10-INCH DIAMETER FOV IMAGING VOLUME. FOR TORSO ORGANS, THE THREE DETECTORS FOLLOW THE BODY CONTOUR ORBIT FOR BEST RESOLUTION.FOR FAST DYNAMIC IMAGING, THREE DETECTORS ROTATE CONTINUOUSLY CW AND CCW WITH THE REVERSING TIME LESS THAN 1 SECOND. THIS DRASTIC REDUCTION OF SPECT IMAGING TIME IS PARTICULARLY IMPORTANT FOR VERY SICK PATIENTS AND FOR PEDIATRIC IMAGING.