Abstract

Radiology departments have contributed significantly to greenhouse gases including release of toxic imaging contrast media to environment. We feel Radiology also has several spectroscopy and imaging tools that may apply to monitor and support cleaner environmental goals. The current manuscript is one of the firsts to prompt Radiology to move in that direction by non-invasive imaging of bio metals that are less abundant in biological tissues but play key roles as co-factors in tissue structure and function. Conventional analytical tools are mostly invasive and cannot characterize the native oxidation states of bio metals. We chose carbohydrate matrix of metal-rich fruits and optimized two non-invasive imaging methods to detect changes in bio metal distribution as the samples were allowed to dry over time. It complements our prior work in Tomography Journal that demonstrated breakdown of specific radiological contrast media causing inflow of lanthanides and iodinated compounds to agricultural products and alter homeostasis by chelation and transmetallation. We observed that in the 20–30 keV range, that is at low end of clinical X-ray, commercial mammography detectors can detect alkali, alkaline earth, and transition metals in fruit samples irrespective of their oxidation states with appropriate X-ray filters utilizing preferential photoelectric absorption while high field magnetic resonance imagers (MRI) can localize paramagnetic states of certain minerals due to their ability to accelerate proton T₂* decay and was used here to study biological tissues at different stages of dehydration. We also observed a central, radial shift of iron distribution from cortex toward the core for partially dried Apples indicative of porosity changes with de-moisturization. However, at this time our approach is unable to convincingly separate the susceptibility effects of paramagnetic bio metals from susceptibility effects of porosity changes during dehydration. We believe this work has two novel aspects: first, that MRI and X-ray could be used for complementary roles to map distribution of paramagnetics rich species, and secondly, ionic transport during heat processing of agricultural products or crops grown in arid land can be monitored for altered bio metal distribution by low energy X-ray as well as by high field MRI. In vivo applications may be possible to exploit MR susceptibility of native bio metals to localize abnormal iron distribution in neurodegeneration.

摘要

放射科对温室气体排放做出了重大贡献，包括向环境释放有毒成像造影剂。我们认为放射学也有多种光谱学和成像工具，可用于监测和支持更清洁的环境目标。目前的手稿是第一批通过对生物金属进行非侵入性成像来促使放射学朝这个方向发展的手稿之一，生物金属在生物组织中含量较少，但在组织结构和功能中作为辅助因素发挥着关键作用。传统的分析工具大多是侵入性的，无法表征生物金属的天然氧化态。我们选择了富含金属的水果的碳水化合物基质，并优化了两种非侵入性成像方法，以检测随着样品随着时间的推移而变干时生物金属分布的变化。它补充了我们之前在 Tomography Journal 上的工作，证明了特定放射造影剂的分解导致镧系元素和碘化化合物流入农产品，并通过螯合和金属转移改变体内平衡。我们观察到，在 20-30 keV 范围内，即临床 X 射线的低端，商业乳腺 X 光检测器可以检测水果样品中的碱金属、碱土金属和过渡金属，而不管它们的氧化态如何，使用适当的 X 射线过滤器利用优先光电吸收，而高场磁共振成像仪 (MRI) 可以定位某些矿物的顺磁性状态，因为它们能够加速质子 T₂ * 衰变，在这里用于研究处于不同脱水阶段的生物组织。对于部分干燥的苹果，我们还观察到铁分布从皮质向核心的中心径向移动，这表明孔隙率随去湿而变化。然而，目前我们的方法无法令人信服地将顺磁性生物金属的磁化率效应与脱水过程中孔隙率变化的磁化率效应区分开来。我们认为这项工作有两个新颖的方面：首先，MRI 和 X 射线可以作为互补作用来绘制富含顺磁性物种的分布图，其次，可以研究在干旱地区种植的农产品或作物在热处理过程中的离子传输。通过低能 X 射线和高场 MRI 监测改变的生物金属分布。体内应用可能会利用天然生物金属的 MR 敏感性来定位神经变性中的异常铁分布。