Diagnosis of Thyroid Nodules Using Virtual Touch Tissue Quantification Value and Anteroposterior/Transverse Diameter Ratio

This paper proposes an effective approach to differential diagnosis of thyroid nodules using a hierarchical classification model based on the Virtual Touch tissue quantification (VTQ) value and anteroposterior/transverse diameter (A/T) ratio. One hundred twenty nodules (92 benign, 28 malignant) were analyzed using this approach by combining the quantitative elastic characteristic with the conventional sonographic feature. First, nodules were classified as benign (VTQ values <2.27 m/s), malignant (VTQ values >2.73 m/s) and indeterminate (2.27 m/s ≤ VTQ values ≤2.73 m/s) using two cutoff points selected on the basis of receiver operating characteristic analysis. Second, the indeterminate nodules were separated into malignant and benign nodules using an A/T ratio ≥1. The advantage of this approach was that it could alleviate the limitation of an overlap in VTQ values between benign and malignant nodules. According to the pathologic results, the accuracy of this approach was 95%. The proposed approach may potentially improve diagnostic accuracy.     

二维超声、实时组织弹性成像及声触诊组织量化技术诊断乳腺浸润性导管癌

目的 探讨二维超声(2D-US)、实时组织弹性成像(UE)及声触诊组织量化(VTQ)技术对乳腺浸润性导管癌(IDC)的诊断价值。方法 对188例患者共213个乳腺病灶术前分别行2D-US、UE及VTQ检查,对各病灶2D-US声像图表现进行超声乳腺影像报告数据系统(BI-RADS-US)分类,UE采用5级评分法判断结节性质,VTQ技术定量测定结节内剪切波速度(SWV)。绘制ROC曲线,比较2D-US、UE、SWV曲线下面积(AUC)。结果 2D-US诊断IDC的敏感度为82.35%(126/153),特异度为71.67%(43/60),准确率为79.34%(169/213)。UE诊断IDC的敏感度为86.27%(132/153),特异度为73.33%(44/60),准确率为82.63%(176/213)。良性及恶性结节的SWV别为(3.09±1.26)m/s、(6.83±2.18)m/s(P<0.05);以3.59 m/s作为诊断恶性病灶的最佳截断值,VTQ诊断IDC的敏感度为86.93%(133/153),特异度为76.67%(46/60),准确率为84.04%(179/213)。2D-US、UE、SWV诊断乳腺IDC的AUC分别为0.811、0.843、0.899,差异有统计学意义(P<0.01)。结论 US、UE及VTQ均有助于鉴别诊断乳腺良性结节及乳腺IDC,UE优于2D-US,VTQ可获得客观的量化指标,重复性好,优于UE和2D-US。     

声触诊组织量化技术评估经颈静脉肝内门体分流术联合胃冠状静脉栓塞术疗效

目的 探讨应用声触诊组织量化(VTQ)技术测量脾脏剪切波速度(SSWV)无创评价经颈静脉肝内门体分流术(TIPS)联合胃冠状静脉栓塞术(GCVE)疗效的价值。方法 将19例接受TIPS联合GCVE治疗的肝硬化门静脉高压患者分为A(13例,接受1次治疗)、B(6例,首次治疗后因支架闭塞再次接受治疗)两组。应用VTQ技术分别与治疗前1天、治疗后6天测量SSWV,以脉冲波多普勒测量门静脉主干血流速度(PVV)、脾静脉主干血流速度(SVV)。于TIPS联合GCVE治疗过程中,以直接测压法测量支架植入前及植入后的门静脉压(PPG),并进行统计分析。结果 TIPS联合GCVE治疗后,A、B两组PPG均较治疗前明显减低(P均<0.05);SSWV均较治疗前明显减低,PVV、SVV均较治疗前明显升高(P均<0.05)。A、B两组治疗前及治疗后SSWV均与PPG呈正相关(P均<0.05),PVV、SVV均与PPG无相关性(P均>0.05)。结论 应用VTQ技术所测SSWV与PPG存在相关性,可作为TIPS联合GCVE治疗前后监测门静脉压力的无创定量评估指标。     

声触诊组织量化鉴别诊断甲状腺实性结节的良恶性

目的 探讨声触诊组织量化技术(VTQ)在甲状腺实性结节良恶性鉴别诊断中的应用价值。方法 采用VTQ技术测量经病理证实的101例患者共129个甲状腺实性结节及周边甲状腺组织剪切波速度(SWV),以病理诊断为金标准,绘制SWV诊断甲状腺实性恶性结节的ROC曲线,获得结节SWV诊断恶性结节的最佳截点。结果 甲状腺实性恶性结节的SWV[(3.15±1.91)m/s]大于良性结节[(2.06±0.54)m/s,P<0.01]。以SWV=2.43 m/s为截点诊断甲状腺实性恶性结节的敏感度、特异度分别为67.80%(40/59)、91.43%(64/70)。甲状腺恶性结节与周边甲状腺组织SWV比值(1.56±0.86)大于良性结节与周边甲状腺组织SWV比值(1.00±0.29,P<0.01)。结论 VTQ技术可量化甲状腺结节硬度,对鉴别诊断甲状腺实性结节具有较高的应用价值。     

声触诊组织定量技术鉴别诊断甲状腺良恶性结节

目的 探讨声触诊组织定量成像(VTQ)鉴别诊断甲状腺良恶性结节的价值。方法 收集48例经手术或穿刺病理证实的甲状腺结节患者,均行常规超声及VTQ检查,获得结节及结节周围组织的剪切波速度(SWV),采用ROC曲线进行统计学分析。结果 良性结节及其周围组织的SWV分别为(2.05±0.25)m/s 、(1.78±0.26)m/s(95%CI:1.68~1.88 m/s),恶性结节及其周围组织SWV分别为(3.57±1.29)m/s(95%CI:3.06~4.09 m/s)、(1.85±0.29)m/s(95%CI:1.73~1.96 m/s)。良性结节与恶性结节、良性结节与其周围组织、恶性结节与其周围组织间SWV的差异均有统计学意义(P均<0.001),而良性结节周围组织与恶性结节周围组织间SWV的差异无统计学意义(P=0.5006)。应用SWV诊断甲状腺恶性结节的ROC曲线下面积为0.9927,截断值为2.416 m/s,敏感度、特异度、阳性预测值、阴性预测值、阳性似然比及阴性似然比分别为88.89%(24/27)、96.43%(27/28)、96.00%(24/25)、90.00%(27/30)、24.89及0.12。结论 VTQ检查能够通过SWV值反映出结节及其周围组织的硬度,在对甲状腺结节良恶性的鉴别诊断中具有重要价值。     

声学结构定量技术评估乙肝肝纤维化程度的临床价值

目的 通过对乙肝患者肝脏声学结构定量(ASQ)分析与病理及Fibroscan结果对比,初步探讨ASQ技术对乙肝肝纤维化分期的诊断价值.方法 收集在我院确诊为慢性乙型肝炎患者66例,进行ASQ分析和Fibroscan检查,继之行肝脏穿刺活检.结果 随着肝纤维化程度的增加,ASQ定性分析彩色编码图表现为黄绿色区减少,红色区域增加,且不规则;ASQ定量分析图表现为红色曲线峰值变小,蓝色曲线峰值变大,曲线下面积增大.ASQ定量参数BR-Ratio值在各组之间均有显著性差异(P＜0.05)且与肝纤维化分期有较好正相关(r=0.772,P＜0.05),当S≥1、S≥2、S≥3、S≥4时BR-Ratio值的曲线下面积(AUC)分别为0.832、0.913、0.962、0.974; BR-Ratio值区分S≥1、S≥2、S≥3、S≥4的截断值分别为0.33、0.37、0.49、0.55.对ASQ及Fibroscan的AUC进行比较,P均＞0.05.结论 ASQ技术对肝纤维化程度的诊断价值与Fibroscan相近,在肝纤维化定量诊断中具有潜在的临床应用前景.     

声脉冲辐射力成像声触诊组织定量技术鉴别诊断颈部淋巴结良恶性的价值

目的探讨声脉冲辐射力成像(ARFI)声触诊组织定量(VTQ)技术在颈部淋巴结良恶性鉴别诊断中的应用价值。方法对65例100个颈部淋巴结肿大患者进行VTQ检查,测量并记录其横向剪切波速度(SWV),比较良恶性颈部淋巴结间SWV的差异;以病理诊断为金标准,绘制ROC曲线图,获取区分颈部淋巴结良恶性SWV的临界值。结果非特异性反应性淋巴结组SWV值为(1.72±0.89)m/s,恶性淋巴结组SWV值为(2.68±0.48)m/s,二者比较差异有统计学意义(T=4.7141,P0.001)。构建SWV的ROC曲线后,其曲线下面积分别为0.862,根据ROC曲线选取鉴别良恶性淋巴结的SWV值的临界值为1.90 m/s,其对应的敏感性、特异性、准确性为82.2%、90.0%、90.0%。结论 ARFI的VTQ技术可定量反映组织弹性特征,有助于鉴别颈部淋巴结的良恶性。     

Evaluation of lockdown effect on SARS-CoV-2 dynamics through viral genome quantification in waste water,Greater Paris,France, 5 March to 23 April 2020

IntroductionSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of coronavirus disease (COVID-19). People infected with SARS-CoV-2 may exhibit no or mild non-specific symptoms; thus, they may contribute to silent circulation of the virus among humans. Since SARS-CoV-2 RNA can be detected in stool samples, monitoring SARS-CoV-2 RNA in waste water (WW) has been proposed as a complementary tool to investigate virus circulation in human populations.AimTo test if the quantification of SARS-CoV-2 genomes in WW correlates with the number of symptomatic or non-symptomatic carriers.MethodWe performed a time-course quantitative analysis of SARS-CoV-2 by RT-qPCR in raw WW samples collected from several major WW treatment plants in Greater Paris. The study period was 5 March to 23 April 2020, including the lockdown period in France (from 17 March).ResultsWe showed that the increase of genome units in raw WW accurately followed the increase of human COVID-19 cases observed at the regional level. Of note, the viral genome could be detected before the epidemic grew massively (around 8 March). Equally importantly, a marked decrease in the quantities of genome units was observed concomitantly with the reduction in the number of new COVID-19 cases, 29 days following the lockdown.ConclusionThis work suggests that a quantitative monitoring of SARS-CoV-2 genomes in WW could generate important additional information for improved monitoring of SARS-CoV-2 circulation at local or regional levels and emphasises the role of WW-based epidemiology.     

Automated 3D Ιnterstitial Lung Disease Εxtent Quantification: Performance Evaluation and Correlation to PFTs

In this study, the performance of a recently proposed computer-aided diagnosis (CAD) scheme in detection and 3D quantification of reticular and ground glass pattern extent in chest computed tomography of interstitial lung disease (ILD) patients is evaluated. CAD scheme performance was evaluated on a dataset of 37 volumetric chest scans, considering five representative axial anatomical levels per scan. CAD scheme reliability analysis was performed by estimating agreement (intraclass correlation coefficient, ICC) of automatically derived ILD pattern extent to semi-quantitative disease extent assessment in terms of 29-point rating scale provided by two expert radiologists. Receiver operating characteristic (ROC) analysis was employed to assess CAD scheme accuracy in ILD pattern detection in terms of area under ROC curve (A_z). Correlation of reticular and ground glass volumetric pattern extent to pulmonary function tests (PFTs) was also investigated. CAD scheme reliability was substantial for ILD extent (ICC = 0.809) and distinct reticular pattern extent (0.806) and moderate for distinct ground glass pattern extent (0.543), performing within inter-observer agreement. CAD scheme demonstrated high accuracy in detecting total ILD (A_z = 0.950 ± 0.018), while accuracy in detecting distinct reticular and ground glass patterns was 0.920 ± 0.023 and 0.883 ± 0.024, respectively. Moderate and statistically significant negative correlation was found between reticular volumetric pattern extent and diffusing capacity, forced expiratory volume in 1 s, forced vital capacity, and total lung capacity (R = −0.581, −0.513, −0.494, and −0.446, respectively), similar to correlations found between radiologists’ semi-quantitative ratings with PFTs. CAD-based quantification of disease extent is in agreement with radiologists’ semi-quantitative assessment and correlates to specific PFTs, suggesting a potential imaging biomarker for ILD staging and management.     

Reliability of MRSI brain temperature mapping at 1.5 and 3 T

MRSI permits the non‐invasive mapping of brain temperature in vivo, but information regarding its reliability is lacking. We obtained MRSI data from 31 healthy male volunteers [age range, 22–40 years; mean ± standard deviation (SD), 30.5 ± 5.0 years]. Eleven subjects (age range, 23–40 years; mean ± SD, 30.5 ± 5.2 years) were invited to receive four point‐resolved spectroscopy MRSI scans on each of 3 days in both 1.5‐T (TR/TE = 1000/144 ms) and 3‐T (TR/TE = 1700/144 ms) clinical scanners; a further 20 subjects (age range, 22–40 years; mean ± SD, 30.5 ± 4.9 years) were scanned on a single occasion at 3 T. Data were fitted in the time domain to determine the water–N‐acetylaspartate chemical shift difference, from which the temperature was estimated. Temperature data were analysed using a linear mixed effects model to determine variance components and systematic temperature changes during the scanning sessions. To characterise the effects of instrumental drift on apparent MRSI brain temperature, a temperature‐controlled phantom was constructed and scanned on multiple occasions. Components of apparent in vivo temperature variability at 1.5 T/3 T caused by inter‐subject (0.18/0.17 °C), inter‐session (0.18/0.15 °C) and within‐session (0.36/0.14 °C) effects, as well as voxel‐to‐voxel variation (0.59/0.54 °C), were determined. There was a brain cooling effect during in vivo MRSI of 0.10 °C [95% confidence interval (CI): –0.110, –0.094 °C; p < 0.001] and 0.051 °C (95% CI: –0.054, –0.048 °C; p < 0.001) per scan at 1.5 T and 3 T, respectively, whereas phantom measurements revealed minimal drift in apparent MRSI temperature relative to fibre‐optic temperature measurements. The mean brain temperature at 3 T was weakly associated with aural (R = 0.55, p = 0.002) and oral (R = 0.62, p < 0.001) measurements of head temperature. In conclusion, the variability associated with MRSI brain temperature mapping was quantified. Repeatability was somewhat higher at 3 T than at 1.5 T, although subtle spatial and temporal variations in apparent temperature were demonstrated at both field strengths. Such data should assist in the efficient design of future clinical studies. © 2013 The Authors. NMR in Biomedicine published by John Wiley & Sons, Ltd.