An Ultra High Resolution SPECT System Integrated with a High-Field MRI Scanner

描述(申请人提供)：在这个项目中，我们将开发一种新型的成像系统，该系统结合了高场MRI扫描仪和超高分辨率SPECT系统，用于成像胰腺β细胞中的代谢和信号靶点。这个组合系统包括一个9.4T 30厘米水平钻孔磁铁(牛津仪器，英国牛津)和Bruker Avance Biospec(Bruker-Biospin，Billerica，MA)控制台，配备12厘米屏蔽梯度，最大强度为400mT/m，以及一个紧凑和超高分辨率的SPECT系统，该系统将安装在直径12厘米的直径内，以便同时对小鼠进行磁共振和SPECT成像。所提出的SPECT系统基于能量分辨光子计数探测器。它由像素化的CdZnTe(CZT)晶体(350 5M宽350 5米)和定制设计的读出电路组成，读出电路利用能量分辨光子计数(ERPC)ASIC(由UI的孟博士团队开发)来读出阳极像素，NCI-ASIC(由布鲁克海文国家实验室和海军研究实验室开发)来读出阴极信号。ERPC探测器提供(A)140keV 3射线的超高固有空间分辨率(在所有三个维度上均为400 5m)，(B)覆盖12-200keV的宽动态范围，(C)与最小磁性组件经证实的MRI兼容性，(D)能够提取在相邻阳极像素和阴极上同时感应的信号，这为纠正强磁场引起的事件定位误差提供了关键信息，以及(E)用于将多个探测器装入MRI孔的紧凑外形。该成像系统结合了高场(9.4T)核磁共振扫描仪和超高SPECT系统。它可以很好地配准MR和SPECT图像中解析的特征。该系统将用于成像胰岛β细胞中的代谢和信号靶点。研究结果将加深我们对每种成像方式在2细胞丢失和复制的特定模型中的优势和局限性的理解。

DESCRIPTION (provided by applicant): In this project, we will develop a novel imaging system that combines a high-field MRI scanner and an ultrahigh resolution SPECT system for imaging metabolic and signaling targets in the pancreatic beta cell. This combined system comprises a 9.4 T 30 cm horizontal bore magnet (Oxford Instrument, Oxford, UK) with Bruker Avance Biospec (Bruker-Biospin, Billerica, MA) console equipped with 12 cm shielded gradient with maximum strength of 400mT/m, and a compact and ultrahigh resolution SPECT system that will be fitted inside the 12 cm diameter bore to allow simultaneous MR and SPECT imaging of mouse. The proposed SPECT system is based on an energy-resolved photon counting detector. It consists of pixelated CdZnTe (CZT) crystals (with 350 5m W 350 5m pitch), coupled to a custom- designed readout circuitry that utilizes an energy-resolved photon-counting (ERPC) ASIC (developed by Dr. Meng's group at UI) to readout anode pixels and the NCI-ASIC (developed by Brookhaven National Laboratory and Naval Research Laboratory) to readout the cathode signals. The ERPC detector offers (a) an ultrahigh intrinsic spatial resolution (<400 5m in all three dimensions) for 140keV 3-rays, (b) a wide dynamic range to cover 12-200keV, (c) a proven MRI- compatibility with minimized magnetic components, (d) the ability to extract signals simultaneously induced on adjacent anode pixels and the cathode, which provides critical information for correcting the event positioning error induced by the strong magnetic field, and (e) a compact form factor for packing multiple detectors into the MRI bore. The proposed imaging system combines a high-field (9.4 T) MRI scanner with an ultrahigh SPECT system. It allows an excellent co-registration of the features resolved in both MR and SPECT images. The proposed system will be applied for imaging metabolic and signaling targets in the pancreatic beta cell. The results of studies will enhance our understanding of the advantages and limitations of each imaging modality in specific models of 2cell loss and replication.