FP7 FMTXCT Project UMCE-HGUGM second year activity report Partner FIHGM Laboratorio de Imagen Médica. Medicina Experimental Hospital Universitario Gregorio Marañón, Madrid

Workpackage 2: XCT development Workpackage 8: FMT-XCT imaging accuracy versus PET-XCT

Workpackage 2: XCT development Use of X-ray contrast agents Double exposure techniques Dual energy X-ray source

Fenestra Iopamiro Use of X-ray contrast agents

Increase in CT number shown by the different contrast agents, Fenestra (A) and Iopamiro (B). Both scans were performed with the same settings, 50 kV peak voltage, 200 µA anode current and 125 µm pixel size.

Detector Dynamic Range Expansion Dual-Exposure technique Dual exposure CNR (PTFE/Air) = Single exposure CNR (PTFE/Air) = 13.91

Detector Dynamic Range Expansion Dual-Exposure technique

Detector Dynamic Range Expansion Dual-Exposure technique

Workpackage 2: XCT development Use of X-ray contrast agents Double exposure techniques Dual energy X-ray source

Multi-Energy data acquisition/processing New Tube Features Voltage setting range40 to 110 kV Current setting range10 to 800 μA Output windowBeryllium (thickness 500 μm) Focal spot size15 μm (6 W) – 80 μm (50 W) Emission angle62 deg (max) Power50 W

July 10 th

September 2009

Work plan for the first semester of 2010 Deploy FIBHGM FDK code in CEA-LETI Start the dual-energy experiment in FIBHGM using the new CT Exchange visits with CEA-LETI to carry out live-animal experiments with contrast and dual-energy techniques

Workpackage 8: FMT-XCT imaging accuracy versus PET-XCT

Materials selection for the optical phantom construction Water Gelatin Silicon Ti02 Pro Jet Polyester resin India ink Lipid emulsions (Intralipid) Polymer microspheres Bulk materialsScatterersAbsorbers ++

Phantom design Heterogeneities 4 mm Fluorescent spheres, 2 mm (Should their size vary?)

Material autofluorescence?

PET quantification

NEMA NU

Metrics for comparison Resolution given by FWHM of a point spread function (PSF) [1,2]. Noise of the image background [3], noise=STD/ mean. Characterization of FMT: metrics [1] Culver et al. Three-dimensional diffuse optical tomography in the parallel plane transmission geometry. Med Phys 30 (2), [2] Patwardhan et al. Time-dependent whole-body fluorescence tomography of probe bio- distributions in mice. Optics Express 13 (7), [3] Ros et al. The influence of a relaxation parameter on SPECT iterative reconstruction algorithms. PMB1994

Relaxation parameter: 0.001, 0.005, 0.01, 0.05, 0.1, 0.2, 0.5, 0.7, 1, 1.5 Number of iterations: Metrics: noise and resolution. Metrics depend on (reconstructing with ART) Relaxation parameter. Number of iterations. Depth. Methods: ART. Compute metrics for range of parameters. Characterization of FMT: influence of parameters

5 iterations.20 iterations.40 iterations. Higher number of iterations, higher resolution. x Resolution versus relaxation parameter and iteration number Y X Z z X(mm) Normalized counts X(mm) Normalized counts X(mm) Normalized counts

Optimum relaxation parameter and iteration number Noise Optimum: 20 iterations y α = (low noise & no so low resolution). Relaxation parameter: 0.001, 0.005, 0.01, 0.05, 0.1, 0.2, 0.5, 0.7, 1, 1.5 Number of iterations: Metrics: noise and resolution. α=0.001 α=1.5 α=0.05 Iteration number α=0.05 α=0.1 α=0.2 α=0.5 α=0.7 α=1 α=1.5 Iteration number

Discussion Metric dependence on parameters and depth complicates comparison. Select/decide for optimum parameters.

Characterization of FMT: linearity R 2 = Can not detect concentrations below 10 3 ~10 4 nM. Any suggestions?