Theory and method of dual-energy x-ray grating phase-contrast imaging

The principle of dual-energy x-ray grating phase-contrast imaging(DEPCI) is clarified by using the theory of x-ray interference and Fresnel diffraction. A new method of retrieving phase from the two interferograms is proposed for DEPCI,and its feasibility is verified via simulation. Finally, the proposed method applied to DEPCI experiment demonstrates the effectiveness of the method. This paper lays the theoretical foundation for performance optimization of DEPCI and the further integration of DEPCI and computed tomography.

Experimental Investigation of Instantaneous Properties of Wave Slamming on the Plate

The purpose of this paper is to investigate the instantaneous properties of wave slanuning on the plate structure of an open structure. The advanced instantaneous measuring technique-Particle Image Velocimetry （PIV） is applied to acquire the instantaneous velocity field of wave slamming. From the cross-correlation analysis results of the images captured by the CCD camera, the flow fields of wave impacting on the structure are displayed visually, and the instantaneous whole- field fluid velocity vectors are obtained. The relation between the instantaneous peak impacting pressures and the instantaneous velocities of water particles is studied by probability analysis.

Instantaneous Real-Time Detection Technology of GLI on FY-4 Geostationary Meteorological Satellite

Lightning is a typical example of an instantaneous random point source target. It has close connection with severe convective phenomena such as a thunderstorm, whose distribution, variation, position and forecasting can be acquired through lightning observation. In this paper, we discuss the way to achieve instantaneous lightning signal intensification and detection from geostationary orbit by using the differences between the lightning signal and the slowly changing background noise such as that of cloud, land and ocean, combining three methods, spectral filtering, spatial filtering and background noise, enabling removal between frames. After six months of operation in orbit, lightning within the coverage of the Geostationary Lightning Imager was effectively detected, strongly supporting the case for shorttime and real-time early warning, forecasting and tracking of severe convective phenomena in China.

The application study of dual-energy CT nonlinearblending technique in pulmonary angiography

Objective This study aimed to explore the feasibility of enhancing image quality in computed tomography(CT) pulmonary angiography (CTPA) and reducing radiation dose using the nonlinear blending (NLB)technique of dual-energy CT.Methods A total of 61 patients scheduled for CTPA were enrolled, and 30 patients underwent dual-energyscanning. Nonlinear blending images (NLB group) and three groups of linear blending images (LB group,80 kV group, and 140 kV group) were reconstructed after scanning;31 patients underwent single-energyscanning (120 kV group). The CT values and standard deviations of the pulmonary trunk, left and rightpulmonary arteries, and ipsilateral back muscle at the bifurcation level of the left and right pulmonaryarteries were measured. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the fivegroups were calculated. The subjective image quality of the five groups was assessed. The radiation dosesof the dual- and single-energy groups were recorded and calculated.Results The CNR and SNR values of blood vessels in the NLB group were significantly higher than thosein the LB, 140 kV, and 80 kV groups (CNR of pulmonary artery trunk: t = 3.50, 4.06, 7.17, all P < 0.05;SNRof pulmonary trunk: t = 3.76, 4.71, 6.92, all P < 0.05). There were no statistical differences in the CNR andSNR values between the NLB group and 120 kV group (P > 0.05). The effective radiation dose of the dualenergygroup was lower than that of the single-energy group (t = –4.52, P < 0.05). The subjective scores ofimages in the NLB group were the highest (4.28 ± 0.74).Conclusion The NLB technique of dual-energy CT can improve the image quality of CTPA and reducethe radiation dose, providing more reliable imaging data for the clinical diagnosis of pulmonary embolism.

瞬时弹性成像技术对乙肝及自身免疫性肝病诊断效能对比分析

目的 探讨瞬时弹性成像技术(fibrotouch,FT)对乙型肝炎及自身免疫性肝病诊断效能对比价值。方法 选取我院收治的乙型肝炎患者59例(A组)、原发性胆汁性胆管炎患者31例(B组),两组均接受肝组织穿刺病理检查,获取患者病理纤维化程度分期;分别对两组进行FT检查,获得两组患者的肝硬度值(LSM),尝试分析患者LSM与病理纤维化分期的关联及差异。结果 两组患者的肝细胞炎症程度、肝组织纤维化变化基本趋于一致,Pearson分析结果显示,炎症、纤维化程度呈正相关(P<0.05);两组无纤维化、轻中度、重度纤维化患者的肝硬度值呈上升趋势,病理分期越严重,LSM越大,且不同病理分期LSM差异有统计学意义(t=234.599,321.819;均P<0.001);两组患者LSM:A组无纤维化、中轻度及重度纤维化患者LSM均低于B组,其中S0分期差异无统计学意义(t=1.780;P=0.079);S1~S2、S3~S4分期差异具有统计学意义(t=8.352,6.392;P<0.001)。结论 FT为无创、定量评估肝病患者肝脏纤维化程度的有效方式,为临床诊治提供科学依据;肝纤维化程度越高则FT检查提示LSM越高;同一病理分期下,乙型肝炎、原发性胆汁性胆管炎患者LSM存在差异;后续可尝试构建不同类型肝炎患者FT检查肝脏损伤程度参考标准。

FibroScan及肝纤维化指数在NAFLD合并HBV感染患者肝纤维化评估中的应用

目的探讨瞬时弹性成像系统(FibroScan)及肝纤维化指数对非酒精性脂肪性肝病(NAFLD)合并HBV感染患者肝纤维化的评估价值。方法回顾性分析2021年6月至2023年6月在三台县人民医院就诊的93例NAFLD合并HBV感染患者的临床资料,经病理学检查结果显示轻中度纤维化70例,重度纤维化23例。收集患者的性别、年龄、体质量指数(BMI)、糖尿病、高血压、饮酒、吸烟、丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、血小板(PLT)、白蛋白(Alb)、HBeAg、NAFLD纤维化评分(NFS)、肝脏硬度测定值(LSM)、肝纤维化指数-4(FIB-4)等。非条件Logistic逐步回归分析NAFLD合并HBV感染患者重度肝纤维化的危险因素;ROC曲线分析LSM、FIB-4对NAFLD合并HBV感染患者肝纤维化的评估价值;Spearman相关系数分析LSM、FIB-4与NAFLD合并HBV感染患者肝纤维化分期的相关性。结果轻中度组ALT、AST、NFS、LSM、FIB-4水平分别为(41.76±8.52)U/L、(31.58±8.07)U/L、-2.62±0.71、(5.75±1.24)kPa、(1.21±0.39),显著低于重度组的(61.89±7.33)U/L、(45.36±12.94)U/L、-1.44±0.45、(10.71±2.97)kPa、(1.88±0.62),轻中度组PLT水平为(177.26±48.31)×10^(9)/L显著高于重度组(138.74±41.65)×10^(9)/L(P<0.05);两组性别、年龄、BMI、糖尿病、高血压、饮酒、吸烟、Alb、HBeAg比较差异无统计学意义(P>0.05)。经多因素logistic回归分析证实,ALT、AST、PLT、NFS、LSM、FIB-4是NAFLD合并HBV感染患者重度肝纤维化的危险因素(P<0.05)。相关性分析结果显示,LSM、FIB-4与NAFLD合并HBV感染患者肝纤维化分期呈正相关(r=0.614、0.583)。ROC曲线分析结果显示,LSM、FIB-4评估NAFLD合并HBV感染患者重度肝纤维化的曲线下面积分别为0.853、0.842,且P<0.05。两者联合评估NAFLD合并HBV感染患者重度肝纤维化的曲线下面积为0.888,敏感度为0.826,特异度为0.929。结论FibroScan及肝纤维化指数在NAFLD合并HBV感染患者肝纤维化评估中均有一定价值,且两者联合效能更高。

基于无人机机载AI模块的电力巡检技术

针对输电线路无人机巡检实时性和准确性的要求,深入研究了YOLOv3目标检测算法在无人机巡检机载AI模块中的应用。利用将目标检测候选区选取和对象识别合二为一的YOLOv3算法,结合多尺度特征融合方式实现了目标检测的高准确性和实时优化,并采用残差块解决了模型退化问题。输电线路绝缘子检测结果表明:YOLOv3算法平均精度可达90%,相同条件下YOLOv3算法平均处理速度约为Faster RCNN算法的3.2倍,约为SSD算法的1.6倍。

基于自适应衰减补偿模型的探地雷达偏移成像及应用研究

为提升隧道复杂围岩条件下雷达法的成像分辨率及检测精度,提出一种基于瞬时属性分析的探地雷达数据自适应衰减补偿模型及逆时偏移技术。通过迭代计算剖面数据中样本点的瞬时幅值,提取时间步的瞬时振幅谱特性及幅值属性,并将瞬时值随时间变化的特征函数作为信号衰减的规律表征,建立自适应指数-线性多项式拟合衰减特征,重构可解析的雷达信号衰减补偿模型;利用衰减补偿模型的逆时偏移成像,最大限度保留有耗媒质深部的异常特征细节信息,实现病害体的高保真成像。以仰拱支护结构的数值模型算例和隧底衬砌实测数据测试该方法的有效性和实用性。结果表明:1)瞬时幅值属性极值主要集中在绕射叠加区及多次反射区;2)多项指数自适应补偿能客观表征雷达数据的衰减特征,确保剖面的高保真特性;3)高信噪比数据可采用n≥5阶次补偿,低信噪比数据宜采用n≥9阶次补偿。

瞬时弹性成像及血清HBsAg、HBV DNA联合评估乙型肝炎肝纤维化程度的价值

目的探讨瞬时弹性成像及血清乙型肝炎表面抗原(HBsAg)、乙型肝炎病毒DNA(HBV DNA)联合评估乙型肝炎肝纤维化程度的价值。方法2019年2月-2023年4月淮南朝阳医院收治77例慢性乙型肝炎患者,患者均接受肝脏穿刺活检判定肝纤维化分期,其中S0期14例、S1期20例、S2期21例、S3期13例、S4期9例。采用Mindray Hepatus 5检测仪检测肝硬度值,检测血清HBsAg、HBV DNA水平。结果S0~S1期、S2期、S3期、S4期肝硬度值分别为(6.02±1.41)、(9.11±1.46)、(11.26±1.38)、(13.05±1.59)kPa,S4期肝硬度值大于S3期,S3期肝硬度值大于S2期,S2期肝硬度值大于S0~S1期(P<0.05);S0~S1期、S2期、S3期、S4期HBsAg水平分别为(216.81±42.09)、(142.68±35.17)、(53.61±11.54)、(26.51±8.14)IU/mL,S0~S1期、S2期、S3期、S4期HBV DNA分别为(1.14××10^(6)±1.79×10^(5))、(1.06××10^(6)±1.54×10^(5))、(9.61×10^(5)±1.39×10^(5))、(8.47×10^(5)±1.33×10^(5))IU/mL,S0~S1期HBsAg水平高于S2期,S2期HBsAg水平高于S3期,S3期HBsAg水平高于S4期,S0~S1期HBV DNA水平高于S3期和S4期,S2期HBV DNA水平高于S4期(P<0.05);经ROC分析,肝硬度值与血清HBsAg、HBV DNA评估肝纤维化程度≥S2期的ROC曲线下面积分别为0.829(95%CI:0.746~0.912)、0.747(95%CI:0.678~0.816)、0.723(95%CI:0.624~0.821),最佳截断值分别为7.362 kPa、148.306 IU/mL、1.092××10^(6) IU/mL,敏感度分别为0.774、0.648、0.679,特异度分别为0.920、0.837、0.863,三项指标联合诊断的曲线下面积为0.907(95%CI:0.861~0.953),敏感度和特异性分别为0.910、0.958,P<0.05。结论瞬时弹性成像及血清HBsAg、HBV DNA单独评估肝纤维化程度≥S2期的慢性乙型肝炎患者均有较好的价值,联合评估时可进一步提高灵敏度和特异度。

心脏超声斑点成像联合基于冠状动脉CTA的瞬时无波形比率与血流储备分数对心肌缺血型冠心病的诊断价值

目的 探讨心脏超声斑点成像联合基于冠状动脉计算机体层血管成像(CTA)的瞬时无波形比率(iFRCT)与血流储备分数(FFRCT)对心肌缺血型冠心病的诊断价值。方法 回顾性分析2020年1月—2023年12月在长安医院接受治疗的106例疑似冠心病心肌缺血患者的病历资料。以冠状动脉造影检查结果为金标准,分为冠心病组与非冠心病组,比较两组的心脏超声斑点成像定量参数、iFRCT、FFRCT,分析冠心病患者发生心肌缺血型冠心病的影响因素,以及心脏超声斑点成像联合i FRCT、FFRCT对心肌缺血型冠心病的诊断价值。结果 冠状动脉造影检查显示,106例研究对象中,心肌缺血42例(39.62%)。冠心病组患者的三维左心室整体应变值、左心室整体径向收缩期峰值应变(GRS)、iFRCT、FFRCT低于非冠心病组(P<0.05)。三维左心室整体应变值[OR=3.688(95%CI:1.315,10.342)]、GRS水平[OR=3.557(95%CI:1.268,9.976)]、iFRCT水平[OR=3.438(95%CI:1.226,9.643)]和FFRCT水平[OR=3.714(95%CI:1.324,10.415)]是发生心肌缺血型冠心病的危险因素(P<0.05)。三维左心室整体应变值、GRS、iFRCT、FFRCT及联合诊断心肌缺血型冠心病的敏感性分别为72%(95%CI:0.63,0.84)、79%(95%CI:0.64,0.92)、67%(95%CI:0.59,0.74)、75%(95%CI:0.66,0.81)、88%(95%CI:0.79,0.97),特异性分别为78%(95%CI:0.61,0.85)、80%(95%CI:0.68,0.87)、73%(95%CI:0.65,0.81)、60%(95%CI:0.52,0.71)、94%(95%CI:0.81,0.99)。结论 心脏超声斑点成像联合i FRCT、FFRCT可用于辅助诊断心肌缺血型冠心病,且诊断效能良好。

Correlation analysis of dual-energy CT iodine maps with quantitative pulmonary perfusion MRI

AIM:To correlate dual-energy computed tomography(DECT) pulmonary angiography derived iodine maps with parameter maps of quantitative pulmonary perfusion magnetic resonance imaging(MRI).METHODS:Eighteen patients with pulmonary perfusion defects detected on DECT derived iodine maps were included in this prospective study and additionally underwent time-resolved contrast-enhanced pulmonary MRI [dynamic contrast enhanced(DCE)-MRI].DCE-MRI data were quantitatively analyzed using a pixel-by-pixel deconvolution analysis calculating regional pulmonary blood flow(PBF),pulmonary blood volume(PBV) and mean transit time(MTT) in visually normal lung parenchyma and perfusion defects.Perfusion parameterswere correlated to mean attenuation values of normal lung and perfusion defects on DECT iodine maps.Two readers rated the concordance of perfusion defects in a visual analysis using a 5-point Likert-scale(1 = no correlation,5 = excellent correlation).RESULTS:In visually normal pulmonary tissue mean DECT and MRI values were:22.6 ± 8.3 Hounsfield units(HU);PBF:58.8 ± 36.0 mL/100 mL per minute;PBV:16.6 ± 8.5 mL;MTT:17.1 ± 10.3 s.In areas with restricted perfusion mean DECT and MRI values were:4.0 ± 3.9 HU;PBF:10.3 ± 5.5 mL/100 mL per minute,PBV:5 ± 4 mL,MTT:21.6 ± 14.0 s.The differences between visually normal parenchyma and areas of restricted perfusion were statistically significant for PBF,PBV and DECT(P < 0.0001).No linear correlation was found between MRI perfusion parameters and attenuation values of DECT iodine maps(PBF:r = 0.35,P = 0.15;PBV:r = 0.34,P = 0.16;MTT:r = 0.41,P = 0.08).Visual analysis revealed a moderate correlation between perfusion defects on DECT iodine maps and the parameter maps of DCE-MRI(mean score 3.6,k 0.45).CONCLUSION:There is a moderate visual but not statistically significant correlation between DECT iodine maps and perfusion parameter maps of DCE-MRI.

Gadolinium Enhances Dual-energy Computed Tomography Scan of Pulmonary Artery

Objective To evaluate the feasibility of using gadopentetate dimeglumine(Gd-DTPA)for dual-energy computed tomography pulmonary angiography(CTPA).Methods Sixty-six patients were randomly divided into three groups and underwent CTPA.Group A had a turbo flash scan using an iohexol injection,Group B had a turbo flash scan using Gd-DTPA,and Group C had a dual-energy scan using Gd-DTPA.The original images of Group C were linearly blended with a blending factor of 0.5 or reconstructed at 40,50,60,70,80,90,100,and 110 keV,respectively.The groups were compared in terms of pulmonary artery CT value,image quality,and radiation dose.Results The pulmonary artery CT values were significantly higher in Group C40keV than in Groups B and C,but lower than in Group A.There was no significant difference in the image noise of Groups C40keV,B,and C.Moreover,Group A had the largest beam hardening artifacts of the superior vena cava(SVC),followed by Groups B and C.Group C40keV showed better vascular branching than the other three groups,among which Group B was superior to Group A.The subjective score of the image quality of Groups A,B,and C showed no significant difference,but the score was significantly higher in Group C40keV than in Groups A and B.The radiation dose was significantly lower in Group B than in Groups A and C.Conclusion Gd-CTPA is recommended to patients who are unsuitable for receiving an iodine-based CTPA.Furthermore,a turbo flash scan could surpass a dual-energy scan without consideration for virtual monoenergetic imaging.

Feasibility of Improved Attenuation Correction for SPECT Reconstruction in the Presence of Dense Materials Using Dual-Energy Virtual Monochromatic CT: A Phantom Study

Objective: Computed tomography (CT)-based attenuation correction (CTAC) offers the clear benefit of reliable reconstruction of single-photon emission computed tomography (SPECT) images through its ability to achieve object-specific attenuation maps, but artifacts from dense materials often deteriorate CTAC performance. Therefore, we investigate the feasibility of CTAC in the presence of dense materials using dual-energy virtual monochromatic CT data. Methods: A sodium pertechnetate-filled cylindrical uniform phantom, with a pair of undiluted iodine syringes attached, is scanned with a dual-source CT scanner to obtain both single-energy (120 kVp) polychromatic and dual-energy (80 kVp/140 kVp with tin filtering) virtual monochromatic CT images. The single-energy and the dual-energy CT images are then converted to attenuation maps at 141 keV. SPECT images are reconstructed from 99mTc emission data of the phantom using each single-energy and dual-energy attenuation map and incorporating CTAC procedure. A region-of-in- terest analysis is performed to quantitatively compare the attenuation maps between the single-energy and the dual-energy techniques, each at an iodine-free position and a position adjacent to the iodine solutions. Results: At the iodine-free position, the phantom provides a uniform distribution of attenuation maps in both the single-energy and the dual-energy techniques. In the presence of adjacent iodine solutions, however, severe artifacts appeare in the single-energy CT images. These artifacts make attenuation values fluctuate, resulting in erroneous pixel values in the CTAC SPECT images. In contrast, dual-energy CT strongly suppresses the artifacts and hence improves the uniformity of the attenuation maps and the resultant SPECT images. Conclusions: Dual-energy CT with virtual monochromatic reconstruction has the potential to substantially reduce artifacts arising from dense materials. It has the potential to improve the accuracy of attenuation maps and the resultant CTAC SPECT images.

Application of Dual-Energy Computed Tomography for Breast Cancer Diagnosis

The present study aimed to investigate the possibility of using dual-energy computed tomography (CT) before therapy to discriminate between normal breast tissue and tumor tissue in patients with breast cancer, without the need to use a contrast medium. The following patient data were extracted by interview and from the hospital’s radiology information system: height, weight, age, menstrual cycle, CT images of normal tissue and tumors with or without contrast medium, and the histopathological diagnosis of the aspiration biopsy. The median age of the 43 participants was 56 years (range, 30 - 80 years). The CT values were evaluated using a clinical analytical program based on the three-material decomposition technique. Breast cancer was classified into ductal carcinoma in situ, invasive ductal carcinoma, invasive lobular carcinoma, fibromatosis-like metaplastic carcinoma, and apocrine carcinoma. In all conditions, regardless of contrast medium, the CT values of tumor tissues were higher than those of normal breast tissue, indicating the effectiveness of dual-energy CT (DE-CT) in the diagnosis of breast cancer. By contrast, DE-CT showed limited potential for distinguishing ductal carcinoma in situ from invasive ductal carcinoma. There have only been a few reports regarding CT examination of breast cancer, and it is expected this study encourage the development of DE-CT imaging to improve tumor detection in patients with breast cancer.

地震映像高精度时频分析方法在铁路隧底隐伏岩溶识别中的应用研究

铁路岩溶隧道隧底隐伏岩溶危及列车行车安全,为了彻底消除安全隐患,保证运营安全,在新建铁路工程静态验收前须完成隧底隐伏岩溶探测、整治设计、整治施工等工作。岩溶探测手段以物探为主钻探为辅,地震映像法作为成熟的物探方法得到了大量应用。地震映像剖面包括时域和频域信息,由于目前用于地震映像时频分析方法计算过程较繁琐、精度不高,实际生产中并未得到广泛应用,资料分析仍以时域的波形特征识别为主,而波形特征具有复杂性、多解性,资料解释准确度不高。这里引入Wigner-Ville改进方法对地震映像剖面进行时频分析,得到高精度的瞬时频率属性剖面,综合利用地震映像剖面的时域和频域信息进行解释,减少了多解性,提高了判释的准确度。本新方法在铁路隧底隐伏岩溶探测中得到了成功验证,对类似岩溶勘探具有重要的借鉴作用。

局部瞬时激励下架空导线微风振动波的传播演化

微风振动是架空导线疲劳断股、断线的重要原因。为分析局部锁定后导线的微风振动过程,将架空导线简化为张力主导的无限长连续弦模型,考虑局部锁定的随机性和瞬时性,将导线在任意时刻任意位置形成的局部锁定简化为瞬时脉冲激励,采用积分变换法获得了系统在时间和空间上的双格林函数解,分析了脉冲波在弦模型中的传播过程和固定约束边界的反射规律。进而采用局部脉冲激励法对导线内行波的传播演化特性进行试验研究,采用高清摄像机对振动波进行捕捉,基于自编程序进行视频图像处理及分析。结果表明:自编程序能够提取标记测点的瞬时位移,脉冲波在传播过程中波速恒定、波面轮廓能够保持较好的形态不变形。局部瞬时激励形成的脉冲波沿导线向两侧档端传播,在经过档端约束后形成反射波沿导线传播,两侧形成的反射波相遇后相互叠加引起导线持续振动。试验现象与理论分析一致。

瞬间之沉醉——论柏拉图对话中的视觉与爱欲

从肉体之眼的观看到灵魂之眼的开启,从感受图像到仰望星空,从欣赏美的身体到观照美本身,视觉问题在柏拉图对话中都非常受重视。无论是从身体还是从灵魂的角度看,视觉总是与人的爱欲相关,这赋予了视觉特殊的内涵。一方面,柏拉图使视觉的即时性导向了爱欲之沉醉,这既是身体层面人与世界和他人互动的不可分离的原初现象,也是灵魂在洞观天宇最高景观时不可言说的深沉奥秘;另一方面,视觉的瞬间性达成了美的事物与美本身之间的跳跃,从而克服了逻各斯的自我封闭和属人智慧的固化,这恰恰孕育了形而上学的反题。必须拨开传统形而上学观念的迷雾,柏拉图对话中视觉本身之于人的重要意义才能得到彰显。

基于遗传-启发算法的微动目标认知ISAR成像资源调度

认知逆合成孔径雷达(Inverse Synthetic Aperture Radar,ISAR)将认知雷达理论与ISAR成像技术相结合,利用目标与环境的离线先验知识及在线感知结果,提升ISAR在复杂环境下的成像能力.与传统单脉冲雷达相比较,相控阵ISAR可实现波束的快速扫描,因此具备多目标观测能力.在实际空间微动目标成像场景中,相控阵ISAR很可能存在多波束多目标情况.为实现系统效能的充分发挥,需要在系统能量、时间资源有限条件下实现成像任务有效调度.然而,面向成像任务的资源调度方法主要针对刚体目标,其约束条件及调度模型并不适用于微动目标,并且存在求解方法稳定性差、调度成功率不高等问题.此外,微动目标运动形式复杂,回波非平稳性很强,且方位缺损时难以聚焦成像.因此,迫切需要针对微动目标的特性,研究有效的ISAR资源调度和高分辨成像方法.针对上述问题,本文提出基于遗传-启发算法的微动目标认知ISAR成像资源调度方法 .该方法首先根据微动目标认知结果计算其成像所需的雷达资源及综合优先级;接着基于脉冲交错技术,在时间、能量双重约束下建立微动多目标资源调度模型.在此基础上,本文提出了基于遗传-启发算法的最优调度求解方法 .进一步,针对资源调度导致微动目标回波缺损,难以聚焦成像的问题,本文提出了基于交替方向乘子法(Alternating Direction Method of Multipliers,ADMM)的距离-瞬时多普勒(Range-Instantaneous Doppler,RID)成像方法,从而实现成功调度任务对应微动目标回波的高分辨聚焦成像.实验结果表明,相比于现有资源调度方法,本文所提方法调度结果更为稳定,调度成功率更高,并可实现回波缺损时的微动目标聚焦成像.

瞬时弹性成像联合彩色多普勒超声规范化半定量评分在早期肝炎肝硬化诊断中的应用价值研究

目的:观察早期肝炎肝硬化诊断中瞬时弹性成像与彩色多普勒超声规范化半定量评分联合应用价值。方法:于2021年1月至2022年1月纳入50例慢性乙肝患者作为观察对象,均进行肝脏活检、彩色多普勒超声以及瞬时弹性成像检查,采用ROC曲线分析单一彩色多普勒超声、单一瞬时弹性成像以及二者联合诊断早期肝炎肝硬化的相关性。结果:彩色多普勒超声规范化半定量评分的ROC曲线下面积0.717,95%CI可信区间0.515~0.919,特异性88.24%、敏感性50.00%、准确性76.00%;瞬时弹性成像的ROC曲线下面积0.899,95%CI可信区间0.779~1.02,特异性91.18%、敏感性68.75%、准确性84.00%;彩色多普勒超声规范化半定量评分与瞬时弹性成像联合检查的ROC曲线下面积0.936,95%CI可信区间0.846~1.01,特异性97.06%、敏感性93.75%、准确性96.00%。结论:早期肝炎肝硬化诊断过程中,彩色多普勒超声规范化半定量评分与瞬时弹性成像联合检查具有较高的准确度,有助于临床规范化抗病毒治疗,减缓肝硬化进展,值得现代临床广泛借鉴。

二维超声剪切波弹性成像评估慢性乙型肝炎患者肝纤维化程度的价值

目的 探讨二维超声剪切波弹性成像评估慢性乙型肝炎患者肝纤维化程度的价值。方法 选取2020年3月至2022年2月医院收治的124例慢性乙型肝炎患者作为研究对象,患者均接受二维超声剪切波弹性成像和瞬时弹性成像检查,以肝穿刺活检病理结果为金标准,分析二维超声剪切波弹性成像和瞬时弹性成像检测不同程度肝纤维化患者的诊断符合率、弹性值。结果 二维超声剪切波弹性成像诊断符合率较瞬时弹性成像诊断高(P<0.05)。S3期患者的弹性值较S1期和S2期高,S2期患者的弹性值较S1期高(P<0.05)。结论 二维超声剪切波弹性成像应用于慢性乙型肝炎诊断中,能提升诊断符合率,有利于判断肝纤维化程度。