PT - JOURNAL ARTICLE AU - Xiaochun Lai AU - Chin-Tu Chen AU - Ling-Jian Meng TI - <strong>MRC-SPECT-DF: An MR-Compatible SPECT System with A Dual-FOV Collimator Design for Microscopic SPECT Imaging</strong> DP - 2015 May 01 TA - Journal of Nuclear Medicine PG - 1870--1870 VI - 56 IP - supplement 3 4099 - http://jnm.snmjournals.org/content/56/supplement_3/1870.short 4100 - http://jnm.snmjournals.org/content/56/supplement_3/1870.full SO - J Nucl Med2015 May 01; 56 AB - 1870 Objectives We will report the design and performance of a MR-compatible SPECT system that utilizes a dual-FOV aperture design for microscopic SPECT imaging of small animals inside pre-existing MR scanners. The MRC-SPECT-DF system consists of a full ring of high resolution CdTe detectors and an aperture that consists of dual-FOV aperture system design that has two sets of aperture rings, one providing a large FOV and the other one allowing an ultrahigh resolution microscopic imaging of a selected target region. The switching between apertures does not require mechanical shifting of either the aperture or the CdTe detector ring, which is critical for minimizing the interference between both SPECT sand MRI sub-systems.Methods The prototype PET imaging setup consists of two HPWF CdTe detectors operated in coincidence around a rotary stage on top of a 3-D translation stage (Fig. 1.a,b). Each HPWF detector has a 2mm x 2.2 cm x 1.1 cm CdTe crystal, with 64x32 anode pixel elements of 350 µm x 350 µm[1]. The dual-FOV (DF) aperture design is shown in Fig. 1.c-e. The DF-aperture assembly consists of 2 rings of pinholes along the axis of the system. The first set has a FOV of around 3.2 cm diameter by 3.2 cm length for providing an overview of the object, and the second one has a smaller FOV of 0.8 cm at a very high spatial resolution of 300um. The aperture design also include a unique shutter-structure that slides into place to block one set of aperture while the other set is in use.Results In this presentation, we will present the SPECT images acquired with the MRC_SPECT-DF system for imaging of resolution phantoms and mice labeled with different SPECT isotopes.Conclusions We have developed an upgrade of the MRC-SPECT system to incorporate a dual-FOC aperture. This design allows the user to switch between two imaging modes, while minimizing the mechanical motion of the aperture and the detection system. This design would allow the user to practically search for target-region and then provide focused microscopic SPECT imaging inside the MR scanners.