Tu & Yuen Center for Functional Onco-Imaging, University of California, Irvine, CA, USA.
Phys Med Biol. 2010 Mar 21;55(6):1563-75. doi: 10.1088/0031-9155/55/6/002. Epub 2010 Feb 17.
In medical imaging, single-photon emission computed tomography (SPECT) can provide specific functional information while magnetic resonance imaging (MRI) can provide high spatial resolution anatomical information as well as complementary functional information. In this study, we developed a miniaturized dual-modality SPECT/MRI (MRSPECT) system and demonstrated the feasibility of simultaneous SPECT and MRI data acquisition, with the possibility of whole-body MRSPECT systems through suitable scaling of components. For our MRSPECT system, a cadmium-zinc-telluride (CZT) nuclear radiation detector was interfaced with a specialized radiofrequency (RF) coil and placed within a whole-body 4 T MRI system. Various phantom experiments characterized the interaction between the SPECT and MRI hardware components. The metallic components of the SPECT hardware altered the B(0) field and generated a non-uniform reduction in the signal-to-noise ratio (SNR) of the MR images. The presence of a magnetic field generated a position shift and resolution loss in the nuclear projection data. Various techniques were proposed to compensate for these adverse effects. Overall, our results demonstrate that accurate, simultaneous SPECT and MRI data acquisition is feasible, justifying the further development of MRSPECT for either small-animal imaging or whole-body human systems by using appropriate components.
在医学成像中，单光子发射计算机断层扫描（SPECT）可以提供特定的功能信息，而磁共振成像（MRI）可以提供高空间分辨率的解剖学信息以及补充的功能信息。在这项研究中，我们开发了一种微型化的 SPECT/MRI（MRSPECT）双模系统，并演示了同时进行 SPECT 和 MRI 数据采集的可行性，通过适当缩放组件，有可能实现全身 MRSPECT 系统。对于我们的 MRSPECT 系统，碲化镉锌（CZT）核辐射探测器与专用射频（RF）线圈相连接，并放置在全身 4 T MRI 系统中。各种体模实验对 SPECT 和 MRI 硬件组件之间的相互作用进行了表征。SPECT 硬件的金属部件改变了 B(0)场，并导致磁共振图像的信噪比（SNR）不均匀降低。磁场的存在导致核投影数据的位置偏移和分辨率损失。提出了各种技术来补偿这些不利影响。总的来说，我们的结果表明，精确、同时的 SPECT 和 MRI 数据采集是可行的，这证明了通过使用适当的组件，MRSPECT 可进一步用于小动物成像或全身人体系统。
