Busse L J, Pratt R G, Thomas S R
Department of Radiology, University of Cincinnati College of Medicine, OH 45267-0579.
J Comput Assist Tomogr. 1988 Sep-Oct;12(5):824-35. doi: 10.1097/00004728-198809010-00020.
The chemical shift spectra of 19F in perfluorinated compounds (PFCs) present a nontrivial impulse response function for magnetic resonance (MR) imaging. The 19F images of organs containing PFCs can be degraded by blurring and ghost image artifacts. Two methods (noise masked deconvolution and maximum entropy deconvolution) are presented that allow the chemical shift spectra of 19F in PFCs to be used to extract high quality MR images free of chemical shift artifact. Both techniques rely on postprocessing of either the raw data or the original image to produce images that are not degraded by the chemical shift spectra of the compound being imaged and that exhibit a signal-to-noise ratio equal to or better than that observed in the original image. The techniques are general in that they can be used with many PFC spectra. Using MR imaging data obtained from phantoms filled with cis/transperfluorodecalin and perfluorotributylamine (FC-43), the methods are compared in terms of their (a) ability to eliminate the chemical shift artifact associated with the PFC spectrum; (b) signal-to-noise performance; and (c) ability to preserve information related to the density and the longitudinal relaxation rate of the resonant nuclei. The utility of these techniques is demonstrated by a series of three-dimensional Fourier transform in vivo images of FC-43 emulsion in a mouse liver.
全氟化合物（PFCs）中¹⁹F的化学位移光谱为磁共振（MR）成像呈现了一个复杂的脉冲响应函数。含有PFCs的器官的¹⁹F图像可能会因模糊和鬼影伪影而退化。本文提出了两种方法（噪声掩蔽反卷积和最大熵反卷积），可利用PFCs中¹⁹F的化学位移光谱来提取无化学位移伪影的高质量MR图像。这两种技术都依赖于对原始数据或原始图像进行后处理，以生成不会因所成像化合物的化学位移光谱而退化且信噪比等于或优于原始图像的图像。这些技术具有通用性，因为它们可用于许多PFC光谱。利用从填充有顺式/反式全氟萘烷和全氟三丁胺（FC - 43）的体模获得的MR成像数据，从以下方面对这些方法进行了比较：（a）消除与PFC光谱相关的化学位移伪影的能力；（b）信噪比性能；（c）保留与共振核的密度和纵向弛豫率相关信息的能力。通过对小鼠肝脏中FC - 43乳剂的一系列三维傅里叶变换体内图像，证明了这些技术的实用性。
