1H磁共振波谱对脑胶质瘤放疗术后应用价值

目的 探讨^1H磁共振波谱（^1H MRS）对脑胶质瘤放疗后疗效监测和预后评估的应用价值。方法 10例经手术病理或临床证实的脑胶质瘤患者，接受40-500y的脑部放射治疗，随访进行^1H MRS检查和磁共振检查。结果 放疗后3-6个月治疗有效3例，^1H MRS表现为Cho下降或明显下降，Cho/Cr明显升高；放疗后1年以上肿瘤放射坏死6例中。NAA、Cr\Cho明显降低或消失，1例2年后肿瘤复发出现明显升高的Cho峰。结论 ^1H MRS可以作为临床监测放疗疗效和评估预后的一种手段。     

Ammonia Concentration in Ambient Air in a Peri-Urban Area Using a Laser Photoacoustic Spectroscopy Detector

Measuring ammonia from the environmental air is a sensitive and prioritized issue due to its harmful effects on humans, ecosystems, and climate. Ammonia is an environmental pollutant that has an important role in forming secondary inorganic aerosols, the main component of fine particulate matter concentrations in the urban atmosphere. Through this study, we present a gas analyzer that utilizes the technique of laser photoacoustic spectroscopy to measure ammonia concentration in three different sites located in Magurele, (44°20′58″ N 26°01′47″ E, 93 m altitude), Romania, from March to August 2021 at the breathing level of 1.5 m above ground. The ammonia concentrations from the ambient air were elevated in summer (mean of 46.03 ± 8.05 ppb (parts per billion)) compared to those measured in spring (18.62 ± 2.92 ppb), which means that atmospheric temperature affects ammonia concentrations. The highest mean ammonia concentrations occurred in August, with an ammonia concentration level of 100.68 ± 11.12 ppb, and the low mean ammonia concentrations occurred in March, with an ammonia level concentration of 0.161 ± 0.03 ppb. The results confirm that meteorological characteristics (i.e., temperature) and motor vehicles are major contributors to the elevated ammonia levels during the monitoring period.     

肥厚型心肌病的MR所见与病理对比的初步探讨

本文报告3例肥厚型心肌病(HCM)患者的MR所见与病理结果。发现HCM其室间隔及左室游离壁厚度远超过正常室壁外,收缩增厚比明显降低。2例心肌病变组织信号强度大部分高于正常心肌,T_2值延长。1例病变组织其信号强度增高呈灶状,并有块状低信号,T_2值短缩。     

首发精神分裂症女性患者基于Stroop范式的近红外光谱成像的脑血流空间特征分析

目的探讨首发精神分裂症女性患者以Stroop范式的近红外光谱成像(NIRS)的脑血流空间特征。方法前瞻性连续纳入2018年1月至2019年12月深圳市康宁医院急性干预科住院的女性首次发作的精神分裂症患者9例,并纳入观察组,同时纳入年龄、受教育年限与观察组相匹配的健康者作为对照组(9例)。以Stroop测试为范式,行NIRS检测,检测时间共74 s,记录NIRS的数据。其中前面10 s为基线期,任务期共64 s,计算相对于基线期的平均氧合血红蛋白(OxyHb)水平,分析NIRS的空间特征。观察组给予奥氮平[平均剂量(17.78±2.92)mg/d]治疗4周,治疗前后各检测1次NIRS,对照组检测1次。结果观察组患者治疗前通道17、18平均OxyHb水平为0.02(-0.02,0.18)、0.04(-0.07,4.11)mmol/L,均高于对照组[-0.22(-0.33,0.04)、-0.35(-0.69,-0.02)mmol/L],通道20治疗前为-0.17(-0.32,0)mmol/L,低于对照组[0.08(-0.08,0.34)mmol/L],差异均有统计学意义(均P<0.05);通道17、18、20治疗后平均OxyHb水平分别为-0.05(-0.21,0.04)、-0.10(-0.24,0.01)、-0.02(-0.21,0.11)mmol/L,与对照组比较,差异均无统计学意义(均P>0.05)。结论女性精神分裂症患者治疗前存在前额叶右腹部中间区负激活及左中间腹外侧区正激活的情况,治疗后有改善。     

Practical Application of Iterative Decomposition of Water and Fat with Echo Asymmetry and Least-Squares Estimation (IDEAL) Imaging in Minimizing Metallic Artifacts

Iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) is a recently developed method for robust separation of fat and water with very high signal-to-noise-ratio (SNR) efficiency. In contrast to conventional fat-saturation methods, IDEAL is insensitive to magnetic field (B0 and B1) inhomogeneity. The aim of this study was to illustrate the practical application of the IDEAL technique in reducing metallic artifacts in postoperative patients with metallic hardware. The IDEAL technique can help musculoskeletal radiologists make an accurate diagnosis particularly in musculoskeletal imaging by reducing metallic artifacts, enabling the use of contrast enhancement, improving SNR performance, and providing various modes of MR images with one scan parameter.     

Medical approach to systems science

Summary

The increasing complexity of Minimally Invasive Therapy and surgery requires the transformation and application of classic systems theory. The basic tools of systems analysis and design are essential to realize technology that functions in a co-ordinated fashion to ensure a safe, smooth and precise execution of interventions or operations on a human being. The paper describes the basic classification of systems and outlines the speculative structure of an MIT Operating System (MITOS) from the medico-technical point of view. Future developments such as remote handled telepresence surgery and CT/MR image-guided surgery are included in the perspective.     

Concentrations of Gd–BOPTA in cholestatic fatty rat livers: role of transport functions through membrane proteins

Gd–BOPTA (gadobenate dimeglumine) is a magnetic resonance (MR) contrast agent that, after i.v. administration, distributes within the extracellular space, enters rat hepatocytes through the sinusoidal transporters organic anion transporting peptides (Oatps) and is excreted unchanged into bile through the multidrug resistance‐associated protein 2 (Mrp2). It is unclear how the hepatobiliary contrast agent would accumulate in cholestatic fatty livers from obese rats with bile flow impairment. Indeed, the expression of both Oatps and Mrp2 transporters is decreased in cholestatic hepatocytes. To assess this question, we measured on‐line the hepatic concentrations of ¹⁵³Gd–BOPTA with a gamma probe placed over perfused rat livers. During the perfusion of ¹⁵³Gd–BOPTA, we obtained a similar maximal hepatic concentration in normal and fatty livers despite the decreased expression and function of membrane transporters in fatty livers. By pharmacokinetic modeling and mathematical simulations, we show how changes of transport into and out of hepatocytes modify the concentrations of ¹⁵³Gd–BOPTA within hepatocytes. Mathematical simulations help to understand how each parameter (entry into hepatocytes, bile excretion, or efflux back to sinusoids) interferes with the hepatic concentrations. The hepatic concentrations of ¹⁵³Gd–BOPTA within hepatocytes rely on the entry into hepatocytes through the sinusoidal membrane and on two paths of exit, the efflux back to sinusoids and the elimination into bile. Understanding how ¹⁵³Gd–BOPTA accumulates in hepatocytes is then complex. However, such understanding is important to analyze liver imaging with hepatobiliary contrast agents in cholestatic fatty livers. Copyright © 2012 John Wiley & Sons, Ltd.