2. Preliminary pinhole SPECT reconstruction results from the NaI detector
Images are displayed as MIP (maximum-intensity-re-projections) animations
Please use slide show mode to see the animation
Projection cine
Reconstruction cine
Fig.25 Misure al Johns Hopkins, Giugno Topo con MDP (si fissa nelle ossa)

3. Sample projection image
Preliminary pinhole SPECT reconstruction results from the CsI detector
Images are displayed as MIP (maximum-intensity-re-projections) animations
2 point sources
APOE mouse (kidneys shown)
Flood image
Sample
projection
image
Fig. 28 APOE mice

4. 99mTc-Annexin-V SPECT images Excised aorta from 37 weeks mouse
APPROACH
Transgenic mouse model
APOE-/- mice
Spontaneous growth of atherosclerotic plaques accelerated by fatty diet
Imaging agent
99mTc-HYNIC-Annexin-V
Binds to apoptotic cells
Imaging techniques
High-resolution pinhole SPECT
99mTc-Annexin-V SPECT images
Excised aorta from 37 weeks mouse
Plaque?
ApomateTM: Trade name for Hynic Annexin V, North American Scientific, Inc.
ApoE-/- mice
20 weeks
Photo autoradiography

5. Spatial resolution: 0.55 mm !!
0.38 mm W pinhole, M=3.3, CsI:Tl array 1 mm step
0.9 capillars, 1.3 mm step
1.1 capillars, 1.5 mm step
0.9 mm 99mTc capillars, 1.3 mm step
Spatial resolution: 0.55 mm !!
FWHM
1.05 mm
1.3 mm

6. Other simulations done for the CsI(Na) option evaluation….

12. spatial resolution/efficiency/ energy resolution
summarizing
CsI(Na) is an interesting option. Unfortunately arrays with pixels smaller than 0.8 mm pitch cannot be built. It is igroscopic, so a window is needed (with spatial resolution degradation) or the integral line layout has to be used.
Careful evaluation of the different options has to be done validating the simulations by measurements first.
Then, decision to be taken on the SNR evaluation base looking at the specific application
Tradeoff
spatial resolution/efficiency/ energy resolution

13. Scaling down (100 mm , 1 mm pitch ---> 50 mm 0.5 mm pitch)Rt
Rt=0.1mm
FOV
FOV~5mm

sensitivity
Trading off…
Choosing the right M to get the best compromise between FOV, Rt and sensitivity
For example, to improve Rt, just sacrify FOV getting at the same time better sensitivity