Magnetic resonance elastography of the lung: technical feasibility.

Magnetic resonance elastography (MRE) is a phase-contrast technique that can spatially map shear stiffness within tissue-like materials. To date, however, MRE of the lung has been too technically challenging-primarily because of signal-to-noise ratio (SNR) limitations and phase instability. We describe an approach in which shear wave propagation is not encoded into the phase of the MR signal of a material, but rather from the signal arising from a polarized noble gas encapsulated within. To determine the feasibility of the approach, three experiments were performed. First, to establish whether shear wave propagation within lung parenchyma can be visualized with phase-contrast MR techniques, MRE was performed on excised porcine lungs inflated with room air. Second, a phantom consisting of open-cell foam filled with thermally polarized (3)He gas was imaged with MRE to determine whether shear wave propagation can be encoded by the gas. Third, preliminary evidence of the feasibility of MRE in vivo was obtained by using a longitudinal driver on the chest of a normal volunteer to generate shear waves in the lung. The results suggest that MRE in combination with hyperpolarized noble gases is potentially useful for noninvasively assessing the regional elastic properties of lung parenchyma, and merits further investigation.     

Role of shear wave elastography measured in the flaccid state in predicting arteriogenic erectile dysfunction

The gold-standard method for diagnosing arteriogenic erectile dysfunction (AED) is the penile Doppler ultrasonography. We proposed a novel method for predicting AED using ultrasonic shear wave elastography (SWE) considering that the former was invasive and variable. A total of 98 male patients were enrolled in our study, referred for ED between December 2018 and October 2020. For comparison, we also included 42 volunteers from the Healthy Physical Examination Center of our hospital. The Penile Doppler Ultrasonography (PDU) and SWE were performed for all patients with the intracavernosal injection (ICI). We named three groups as AED group, nonvascular ED group and healthy controls group. No statistically significant differences were found among the three groups in terms of demographic and clinical characteristics. There were no significant differences in IIEF-5 between AED and nonvascular ED. A significant (r = 0.642, p < 0.0001) positive correlation between flaccid and erectile SWE was observed. With a cut-off value of 13.45 KPa, the area under curve, specificity, and sensitivity of the SWE values under the flaccid state in distinguishing AED from healthy subjects were 0.867, 0.786 and 0.896 respectively. The SWE value in the flaccid state can distinguish the AED from healthy subjects.     

超声技术在肝纤维化诊断中的应用进展

肝纤维化是临床上各类慢性肝病进行性发展的重要病理过程之一,可进一步发展为肝硬化甚至肝癌。肝纤维化的早期诊断对预防各类肝病发展为肝硬化及肝癌具有重要意义。肝穿刺活检是诊断肝纤维化的“金标准”,但其具有创伤性,易引起多种并发症,目前无法作为常规筛查手段。近年来,超声检查技术作为一种无创性肝纤维化诊断方法在临床上得到越来越多的应用,并取得了诸多进展。本文就超声技术在肝纤维化诊断方面的研究现状作一综述。     

医学成像技术的进展

医学成像技术在最近几年中有了飞速的发展，新的成像方法不断涌现，已有的成像方式不断完善。从平面到立体、从局部到整体、从静态到动态、从形态到功能已成为医学成像技术发展的趋势。文中简要介绍分子成像、近红外热成像等新的成像方式。     

剪切波弹性成像鉴别诊断甲状腺良恶性结节

目的:探讨实时剪切波弹性成像技术(shear wave elastography,SWE)在鉴别诊断甲状腺良恶性结节的应用价值。方法:对185例单发甲状腺肿物患者资料进行回顾性分析,评估SWE技术。结果:所有结节经病理证实,61个结节为良性,124个为恶性。恶性结节超声表现常呈低或极低回声,伴多发细点状微钙化,纵横比大于1,边界模糊,形态不规则。恶性结节的最大弹性模量值(Emax)为(58.5±26.5)kPa,平均杨氏模量为(41.8±32.6)kPa。良性结节的最大弹性模量值(Emax)为(38.5±15.7)kPa,平均杨氏模量为(29.5±17.7)kPa,两者之间的差异有统计学意义。最大弹性模量值(Emax)为55.4kPa、平均弹性模量值(Emean) 为45.6kPa、可疑结节与周围正常腺体弹性模量值之比(ER)为1.5,对良恶性结节的鉴别具有较高的灵敏性和特异性。结论:基于超声二维表现,综合SWE技术,对甲状腺结节良恶性进行鉴别诊断具有一定的价值。     

Application of Shear-Wave Elastography in the Evaluation of Hamstring Stiffness in Young Basketball Athletes

BackgroundPrevious literature has postulated a relationship between greater hamstring stiffness and a higher risk of sustaining injury. Shear wave elastography (SWE) presents a relatively new means for non-invasive evaluation of soft tissue elasticity pre- and post- injury or intervention.Purpose1. To establish baseline hamstring stiffness measures for young competitive athletes and (2) determine effect of targeted neuromuscular training (TNMT) on shear wave stiffness of the hamstring.Study DesignUn-blinded, prospective, non-randomized, cohort study.MethodsSix-hundred forty-two lower extremities from 321 high school and collegiate basketball athletes (177 F: 139 M) were examined for hamstring stiffness prior to the start of their competitive basketball season. Teams were cluster assigned to either the control or intervention (TNMT) group. Subjects in the control group underwent regular season activities as directed, with no influence from the research team. For the TNMT group, the research team introduced a hamstring targeted dynamic warm-up program as an intervention focused on activating the hamstring musculature.ResultsCollegiate status was significant to hamstring stiffness for both sexes (p ≤ 0.02), but hamstring stiffness did not correlate to age or sex (r² ≤ 0.08). Intervention was a significant factor to hamstring stiffness when the hip was positioned in extension (p ≤ 0.01), but not in deeper flexion (p = 0.12). This effect was sex-specific as TNMT influenced hamstring stiffness in females (p = 0.03), but not in males (p ≥ 0.13). Control athletes suffered three HAM injuries; TNMT athletes suffered 0 hamstring injuries.ConclusionHigher SWE measurements correlated with increased risk of injury, male sex, and collegiate athletics. TNMT intervention can lessen muscle stiffness which may reduce relate to injury incidence. Intervention effectiveness may be sex specific.Level of EvidenceII     

剪切波弹性成像技术鉴别良恶性乳腺结节的Logistic回归分析

目的:应用Logistic回归模型评价剪切波弹性成像（shear wave elastography,SWE）技术在乳腺结节良恶性鉴别诊断中的价值。方法:对164例患者行常规超声及剪切波弹性成像检查,以病理诊断为金标准建立Logistic回归模型。绘制ROC曲线,评价Logistic回归模型的预报能力,评价剪切波弹性成像技术在乳腺结节良恶性鉴别诊断中的价值。结果:进入回归模型中对乳腺结节良恶性鉴别诊断中有统计学意义的特征变量包括钙化、CDFI、纵横比、弹性模量Emax值及Eratio值。Logistic回归模型对乳腺结节良恶性预报的正确率为91.80%,敏感性为93.10%,特异性为89.90%。结论:剪切波弹性成像技术较常规超声检查更有助于乳腺结节的良恶性鉴别诊断。     

亚急性甲状腺炎超声特征与中医证型相关性评价

目的:探讨亚急性甲状腺炎超声特征与中医证型的相关性。方法:将甲状腺穿刺活检确诊为亚急性甲状腺炎的65例患者纳入研究,对患者实施中医辨证和超声(超声弹性成像)检查,观察不同中医证型患者的超声表现,并对患者的超声检查图像进行分级,比较不同超声分级患者的中医证型。结果:中医证型以风热痰凝证为主,风热痰凝证与肝郁气虚证比较,差异有统计学意义(χ²=4.680,P=0.031)。风热痰凝证与气阴两虚兼痰凝证比较,差异有统计学意义(χ²=8.613,P=0.003)。患者主要超声表现包括甲状腺肿大、片状低回声区、低回声区周围有丰富血流信号、甲状腺上动脉峰值流速>40 cm/s。风热痰凝证各超声表现与气阴两虚兼痰凝证比较,差异有统计学意义(P <0.05);风热痰凝证甲状腺肿大、片状低回声区与肝郁气虚证比较,差异有统计学意义(P <0.05)。风热痰凝证各超声表现(除甲状腺肿大外)与气阴两虚兼痰凝证比较,差异有统计学意义(P <0.05)。超声弹性成像分级Ⅱ级构成比与0级比较,差异有统计学意义(χ²=15.57...