使用小动物多针孔SPECT/PET/CT系统进行再成像性能评估。

Re image performance assessment using small animal multi-pinhole SPECT/PET/CT system.

作者信息

Esquinas Pedro L, Rodríguez-Rodríguez Cristina, Carlos De La Vega José, Bokharaei Mehrdad, Saatchi Katayoun, Shirmohammad Maryam, Häfeli Urs O, Sossi Vesna, Celler Anna

机构信息

Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada.

Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada; Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.

出版信息

Phys Med. 2017 Jan;33:26-37. doi: 10.1016/j.ejmp.2016.11.105. Epub 2016 Dec 20.

DOI:10.1016/j.ejmp.2016.11.105

PMID:28007432

Abstract

PURPOSE

The goal of this study was to investigate the performance of a pre-clinical SPECT/PET/CT system for Re imaging.

METHODS

Phantom experiments were performed aiming to assess the characteristics of two multi-pinhole collimators: ultra-high resolution collimator (UHRC) and high-energy ultra high resolution collimator (HE-URHC) for imaging Re. The spatial resolution, image contrast and contrast-to-noise ratio (CNR) were investigated using micro-Jaszczak phantoms. Additionally, the quantification accuracy of Re images was evaluated using two custom-designed phantoms. The Re images were compared to those obtained with Tc (gold standard); the acquired energy spectra were analyzed and Monte-Carlo simulations of the UHRC were performed. To verify our findings, a C57BL/6-mouse was injected with Re-microspheres and scanned with both collimators.

RESULTS

The spatial resolution achieved in Re images was comparable to that of Tc. Acquisitions using HE-UHRC yielded Re images with higher contrast and CNR than UHRC. Studies of quantitative accuracy of Re images resulted in <10% errors for both collimators when the activity was calculated within a small VOI around the object of interest. Similar quantification accuracy was achieved for Tc. However, Re images showed much higher levels of noise in the background. Monte-Carlo simulations showed that Re imaging with UHRC is severely affected by down-scattered photons from high-energy emissions. The mouse images showed similar biodistribution of Re-microspheres for both collimators.

CONCLUSIONS

VECTor/CT provided Re images quantitatively accurate and with quality comparable to Tc. However, due to large penetration of UHRC by high-energy photons, the use of the HE-UHRC for imaging Re in VECTor/CT is recommended.

摘要

目的

本研究的目的是调查一款临床前SPECT/PET/CT系统用于铼（Re）成像的性能。

方法

进行了体模实验，旨在评估两种多针孔准直器的特性：用于铼成像的超高分辨率准直器（UHRC）和高能超高分辨率准直器（HE - URHC）。使用微型Jaszczak体模研究空间分辨率、图像对比度和对比噪声比（CNR）。此外，使用两个定制设计的体模评估铼图像的定量准确性。将铼图像与用锝（Tc，金标准）获得的图像进行比较；分析采集的能谱并对UHRC进行蒙特卡罗模拟。为了验证我们的发现，给一只C57BL/6小鼠注射铼微球并用两种准直器进行扫描。

结果

铼图像中实现的空间分辨率与锝图像相当。使用HE - UHRC采集得到的铼图像比UHRC具有更高的对比度和CNR。当在感兴趣物体周围的小感兴趣区内计算活度时，两种准直器的铼图像定量准确性研究误差均<10%。锝也实现了类似的定量准确性。然而，铼图像在背景中显示出高得多的噪声水平。蒙特卡罗模拟表明，使用UHRC进行铼成像受到高能发射的向下散射光子的严重影响。小鼠图像显示两种准直器的铼微球生物分布相似。