Figure 4.

Sensitivity of the 3D-freehandSPECT-mobile gamma camera combination compared to 2D-mobile gamma camera and conventional 2D-flatbed imaging. A. Schematic representation of test setup 1 with all dilutions placed within the VOI. B. Schematic representation of test setup 2 in which only the five highest dilutions were placed in the VOI. C. Schematic representation of test setup 3 in which the five highest dilutions were placed at a respective distance from each other. For all the setups shown: I) Schematic overview of the setup; II) Conventional 2D-flatbed imaging of the various setups at a source-detector depth of 60 mm (acquisition time: five min); III) Corresponding 3D-freehandSPECT-mobile gamma camera (3D-FHS-MGC) image at 60 mm Perspex depth; and IV) Resulting sensitivity graphs. The green line represents 2D-MGC imaging. 2D-flatbed imaging is represented by the blue line and 3D-FHS-MGC by the red line. Note to setup 3: To make sure all sources fitted inside the VOI during 3D-FHS-MGC scan acquisition the 1:128 source had to be moved so that it was in the centre of the other four sources, so the source seen in the middle in CIII is actually the 1:128 source.