Speaker
Dr
Christian Lackas
(Research Center Juelich)
Description
Multi-Pinhole SPECT has become a proven modality in small-animal molecular imaging.
Although the spatial-resolution capabilities of SPECT are greater than those of
PET, the latter is generally considered the gold-standard nuclear imaging modality
due to high-sensitivities. In this work, we present a high-throughput SPECT system
that achieves submillimeter reconstructed resolutions while simultaneously
approaching the sensitivity of PET. This increase in sensitivity combined with
existing advantages of SPECT, e.g. tracer chemistry, cost and dual isotope
capabilities, improves the standing of SPECT as a molecular imager. This camera,
the NanoSPECT, consists of four detectors (215x230mm2 NaI, 33 PMTs, 2.1mm intrinsic
resolution at 140keV) mounted on a high-precision gantry. Each detector is
outfitted with an interchangeable 9-pinhole aperture for a total of 36 pinholes
surrounding the field of view (FOV). Pinhole diameter and FOV are chosen in
accordance with the prescribed application, e.g., mouse or rat imaging. The axial
FOV is extended using helical scanning (user-selectable range from 20 to 290mm).
Additionally, helical orbits provide an increase in the angular sampling. All told,
this increase in sensitivity and sampling greatly improves image quality both for
detection and estimation (quantification) as compared to standard SPECT acquisition
techniques. We will present a detailed description of the NanoSPECT along with
numerous phantom studies and small-animal scans performed with an array of Tc-99m,
I-123 and In-111 tracers. The results will address resolution, sensitivity, imaging
times, injected dose and quantification results as well as multi-isotope and
dynamic SPECT capabilities.
Author
Dr
Nils Schramm
(Research Center Juelich)
Co-authors
Dr
Christian Lackas
(Research Center Juelich)
Dr
John Hoppin
(Research center Juelich)
