MollyQ-50™ Specifications

Hardware

Detectors
Eight, very large solid angle (f/0.9), 10,042-hole, point-focus collimators are each coupled to a 54x81 mm crystal array viewed by six, 19 mm PMTs. Foci of the collimators uniformly sample one transaxial slice.Both the 30 and 50 are available in two choices of detectors, the X and G. The X- are limited to imaging I-125 tagged compounds while the G-detectors can image all the commonly used isotope tags.

Sensitive Volume
The field-of-view is 50 mm in diameter within a 70 mm diameter opening. Setting the number of slices and slice spacing determines the volume scanned.

Slice Spacing (Axial Motion)
Selectable from zero to 5 mm in increments of 100 microns. A single slice can be acquired at full sensitivity in as short as 30 seconds. Repeated fast scanning of a specified slice is available.

Reconstructed Resolution
Approximately 800 microns (FWHM) in all directions for objects with adequate counts and contrast. (The corresponding volume resolution is 512 nanoliters.)

Peak Sensitivity
31,000 cps per MBq for each detector.

Physical
Total weight is approximately 100 kg. Gantry is 80 cm high, 60 cm wide and 50 cm deep. The bed extends forward 60 cm. Power required is <500 W.

Gantry Electronics
Each of the eight detector heads has six PMTs, six MCAs and a high voltage supply. A UNIX-based embedded micro-controller is used for motion control and data acquisition from all 48, 256-channel analyzers.
Software

Multitasking
The MollyQ™-50 software supports internal multitasking. This allows a single application to perform "off-line" 3D reconstructions while acquiring data from the scanner, performing slice-by-slice (2D) reconstructions on the incoming data, and simultaneously viewing and analyzing prior studies.

Acquisition
The scan is initiated with the click of a button after selection of setup parameters. Quality control procedures and data acquisition are built into the application. The last 32 QC results are saved.

Reconstruction
There are two forms of reconstruction. Both use the same maximum a-posteriori (MAP) algorithm. The first reconstructs one slice at a time and is intended to provide real-time images to the operator while a scan is in progress. The second is an adaptive, fully 3-dimensional reconstruction providing the highest image quality both in terms of resolution and quantitation. The 3D reconstruction starts only after data from all slices are available and takes approximately 10 to 20 minutes depending on the number of slices acquired.

Display - Analysis
Multiple studies may be viewed concurrently in three orthogonal views using multiple color scales. The user can interact with the image volume to create arbitrary sets of slices along any direction with arbitrary spacing and size. Files exportable in industry standard formats.

Console Computer
The latest standard configuration hi-end Macintosh is included with the scanner. Presently, this 18+ Gflops workstation comes with dual 2.0 GHz PowerPC G5 vector processors, 2 GB SDRAM, a 120 GB hard drive, 1gb/s Ethernet, 4 USB and 2 FireWire ports and a flat 23 inch (1920x1200 pixel) Apple Cinema Display.