Tomography

体层摄影术
  • 文章类型: Journal Article
    背景:当前胸膜间皮瘤(PM)的临床分期通常与病理分期不一致。这项研究旨在确定可以帮助预测PM不可切除性的临床和放射学特征。
    方法:对手术可能可切除的PM患者的术前计算机断层扫描(CT)和/或正电子发射断层扫描/CT(PET/CT)进行回顾性评估。测量胸部三个水平的最大和总胸膜厚度(上,中间,和更低)根据国际肺癌研究协会(IASLC)提供的切点进行分层。临床和放射学特征,包括临床阶段,通过单因素分析和逻辑回归模型比较可切除和不可切除的肿瘤。
    结果:在133名患者中,69/133(52%)可切除,64/133(48%)不可切除的PM。石棉暴露(p=0.005),新辅助治疗(p=0.001),临床T分期(p<0.0001),所有胸膜厚度测量值(p<0.05),胸膜厚度模式(p<0.0001)和程度(p=0.033),肺浸润(p=0.004),胸膜外间隙闭塞(p<0.0001),扩展到次膈空间(p=0.0004),在单变量分析中,代表广泛膈肌接触和/或胸壁受累(p=0.002)和纵隔侵犯(p<0.0001)的两个组合变量是显著的预测因子。在多变量分析中,所有模型均实现了较强的诊断性能(曲线下面积(AUC)>0.8).两个表现最好的模型是包括最高水平最大胸膜厚度的模型,胸膜外间隙闭塞,和纵隔浸润(AUC=0.876),另一个通过临床T分期整合临床变量和放射学评估(AUC=0.879)。
    结论:选定的临床和放射学特征,包括胸膜厚度测量,似乎是PM不可切除的有力预测因素。
    结论:在胸膜间皮瘤患者的术前评估中更准确的不可切除性预测可能避免不必要的手术和及时启动非手术治疗。
    结论:据报道,大约一半的胸膜间皮瘤患者术前出现了不正确的疾病阶段。被确定为不可切除性预测因素的11个特征被包括在强有力的预测模型中。更准确的术前分期将有助于临床医生和患者选择最合适的治疗方法。
    BACKGROUND: The current clinical staging of pleural mesothelioma (PM) is often discordant with the pathologic staging. This study aimed to identify clinical and radiological features that could help predict unresectability in PM.
    METHODS: Twenty-two descriptive radiologic features were retrospectively evaluated on preoperative computed tomography (CT) and/or positron emission tomography/CT (PET/CT) performed in patients with presumably resectable PM who underwent surgery. Measurements of maximum and sum pleural thickness at three levels of the thorax (upper, middle, and lower) were taken and stratified based on the cutpoints provided by the International Association for the Study of Lung Cancer (IASLC). Clinical and radiological features, including clinical-stage, were compared between resectable and unresectable tumors by univariate analysis and logistic regression modeling.
    RESULTS: Of 133 patients, 69/133 (52%) had resectable and 64/133 (48%) had unresectable PM. Asbestos exposure (p = 0.005), neoadjuvant treatment (p = 0.001), clinical T-stage (p < 0.0001), all pleural thickness measurements (p < 0.05), pleural thickness pattern (p < 0.0001) and degree (p = 0.033), lung invasion (p = 0.004), extrapleural space obliteration (p < 0.0001), extension to subphrenic space (p = 0.0004), and two combination variables representing extensive diaphragmatic contact and/or chest wall involvement (p = 0.002) and mediastinal invasion (p < 0.0001) were significant predictors at univariate analysis. At multivariable analysis, all models achieved a strong diagnostic performance (area under the curve (AUC) > 0.8). The two best-performing models were one that included the upper-level maximum pleural thickness, extrapleural space obliteration, and mediastinal infiltration (AUC = 0.876), and another that integrated clinical variables and radiological assessment through the clinical T-stage (AUC = 0.879).
    CONCLUSIONS: Selected clinical and radiologic features, including pleural thickness measurements, appear to be strong predictors of unresectability in PM.
    CONCLUSIONS: A more accurate prediction of unresectability in the preoperative assessment of patients with pleural mesothelioma may avoid unnecessary surgery and prompt initiation of nonsurgical treatments.
    CONCLUSIONS: About half of pleural mesothelioma patients are reported to receive an incorrect disease stage preoperatively. Eleven features identified as predictors of unresectability were included in strongly performing predictive models. More accurate preoperative staging will help clinicians and patients choose the most appropriate treatments.
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  • 文章类型: Journal Article
    ANCA相关血管炎(AAV)包括肉芽肿性多血管炎(GPA),显微镜下多血管炎(MPA)和嗜酸性肉芽肿伴多血管炎。所有形式可能涉及不同的器官系统,然而,在许多情况下,肾脏和肺部受累是常见且致命的。这里,我们旨在确定AAV患者肺部疾病表现和个体CT表现的预测价值.可用的CT扫描和死亡率的临床信息,肾脏结局,对德国三级风湿病中心的复发和损伤评分进行了回顾性分析.我们共纳入94例AAV患者(49例GPA,41与MPA)。44例患者肺部受累,可用CT扫描,其中70.5%伴GPA,72.7%伴肾脏受累。GPA患者中结节形成和空洞更为常见,而毛玻璃混浊(GGO),在MPA患者中主要观察到ILD和胸腔积液。经过37个月的中位随访,GPA患者的总死亡率略高,而MPA患者的终末期肾衰竭率显着增加。复发频率在两个实体之间是相当的。GGO和胸腔积液的存在与较高的复发率相关,而结节与复发呈负相关。值得注意的是,与接受不同疗法的个体相比,接受RTX治疗的患者感染较少。我们的数据证明了特征性CT模式在AAV诊断评估中的重要性。特别是某些CT模式,包括GGO和胸膜积液,可能有助于识别复发性疾病风险较高的患者。
    ANCA-associated vasculitides (AAV) comprise granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis. All forms may involve different organ systems, yet kidney and lung involvement are common and fatal in many cases. Here, we aimed to determine the predictive value of pulmonary disease manifestation and individual CT findings in AAV patients. Available CT scans and clinical information on mortality, renal outcomes, occurrence of relapses and damage scores were analysed retrospectively from a tertiary rheumatology center in Germany. We included a total of 94 AAV patients (49 with GPA, 41 with MPA). Forty-four patients had lung involvement with available CT scans, 70.5% of which with GPA and 72.7% with renal involvement. Nodule formation and cavities were more frequent among GPA patients, whereas ground-glass opacities (GGO), ILD and pleural effusion were observed predominantly in MPA patients. Over a median follow-up of 37 months, GPA patients had a slightly higher overall mortality, whereas end-stage kidney failure rates were significantly increased in MPA patients. Relapse frequencies were comparable between both entities. The presence of GGO and pleural effusion were associated with higher relapse rates, whereas nodules were negatively correlated with relapses. Notably, RTX-treated patients had less infections as compared to individuals under different therapies. Our data demonstrate the outstanding importance of characteristic CT patterns in AAV diagnosis assessment. Especially certain CT patterns including GGO and pleura effusion may help to identify patients who are at higher risk for relapsing disease.
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  • 文章类型: Journal Article
    背景:随着用于治疗非小细胞肺癌的免疫检查点抑制剂的发展,对新的功能成像技术和早期反应评估的需求增加,以解释新的反应模式和高昂的治疗成本.本研究旨在评估动态对比增强计算机断层扫描(DCE-CT)对接受免疫检查点抑制剂治疗的非小细胞肺癌患者生存结果的预后影响。
    方法:将使用免疫检查点抑制剂治疗的33例不能手术的非小细胞肺癌患者纳入DCE-CT作为随访的一部分。基线时的单个靶病变和随后的随访检查被封闭在DCE-CT中。血容量去卷积(BVdecon),血流量去卷积(BFdecon),在KaplanMeier和Cox回归分析中,使用总生存期(OS)和无进展生存期(PFS)作为终点来评估血流最大斜率(BFMax斜率)和通透性.
    结果:高基线血容量(BVdecon)(>12.97ml×100g-1)与良好的OS(26.7vs7.9个月;p=0.050)和PFS(14.6vs2.5个月;p=0.050)相关。在第7天的早期随访中,BFdecon的相对升高(OS>24.50%,PFS>12.04%)与不良OS(8.7个月vs23.1个月;p<0.025)和PFS(2.5vs13.7个月;p<0.018)相关。第7天BFdecon(分类)的相对变化是OS(HR0.26,CI95:0.06至0.93p=0.039)和PFS(HR0.27,CI95:0.09至0.85p=0.026)的预测因子。
    结论:在接受免疫检查点抑制剂治疗的NSCLC患者中,在基线和早期治疗期间,DCE-CT鉴定的参数可能作为潜在的预后生物标志物。
    BACKGROUND: With the development of immune checkpoint inhibitors for the treatment of non-small cell lung cancer, the need for new functional imaging techniques and early response assessments has increased to account for new response patterns and the high cost of treatment. The present study was designed to assess the prognostic impact of dynamic contrast-enhanced computed tomography (DCE-CT) on survival outcomes in non-small cell lung cancer patients treated with immune checkpoint inhibitors.
    METHODS: Thirty-three patients with inoperable non-small-cell lung cancer treated with immune checkpoint inhibitors were prospectively enrolled for DCE-CT as part of their follow-up. A single target lesion at baseline and subsequent follow-up examinations were enclosed in the DCE-CT. Blood volume deconvolution (BVdecon), blood flow deconvolution (BFdecon), blood flow maximum slope (BFMax slope) and permeability were assessed using overall survival (OS) and progression-free survival (PFS) as endpoints in Kaplan Meier and Cox regression analyses.
    RESULTS: High baseline Blood Volume (BVdecon) (> 12.97 ml × 100 g-1) was associated with a favorable OS (26.7 vs 7.9 months; p = 0.050) and PFS (14.6 vs 2.5 months; p = 0.050). At early follow-up on day seven a higher relative increase in BFdecon (> 24.50% for OS and > 12.04% for PFS) was associated with an unfavorable OS (8.7 months vs 23.1 months; p < 0.025) and PFS (2.5 vs 13.7 months; p < 0.018). The relative change in BFdecon (categorical) on day seven was a predictor of OS (HR 0.26, CI95: 0.06 to 0.93 p = 0.039) and PFS (HR 0.27, CI95: 0.09 to 0.85 p = 0.026).
    CONCLUSIONS: DCE-CT-identified parameters may serve as potential prognostic biomarkers at baseline and during early treatment in patients with NSCLC treated with immune checkpoint inhibitor therapy.
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  • 文章类型: Journal Article
    自下而上的生长提供了对半导体纳米线(NWs)的结构和几何形状的精确控制,使广泛的可能的形状和无缝异质结构的应用在纳米光子学和电子学。最常见的气-液-固(VLS)生长方法具有液态金属催化剂液滴与晶体NW的各向异性结构之间的复杂相互作用,增长主要由三相线(TPL)协调。尽管液滴和NW对称性之间存在固有的不匹配,由于它的复杂性,它的讨论在很大程度上被避免了,这导致了多种观察到的现象,例如NW轴向不对称或TPL的振荡截断,仍然缺乏详细的解释。引入液滴的电场控制引发了更多的问题,如果没有正确解决NW和液滴的三维(3D)结构和形态,就无法回答。这项工作描述了使用环境透射电子显微镜(ETEM)对锗(Ge)NW进行电场控制的VLS生长的细节。我们在不受干扰的生长过程中对液滴NW系统进行TEM层析成像,然后在调节偏置电势的同时跟踪其演化。使用3D有限元方法(FEM)建模和晶体学考虑,我们为VLS增长提供了详细且一致的机制,这自然地解释了基于其晶体结构的生长的NW的观察到的不对称性和特征。我们的发现为制造复杂的3D半导体纳米结构提供了坚实的框架,并最终控制其形态。
    Bottom-up growth offers precise control over the structure and geometry of semiconductor nanowires (NWs), enabling a wide range of possible shapes and seamless heterostructures for applications in nanophotonics and electronics. The most common vapor-liquid-solid (VLS) growth method features a complex interaction between the liquid metal catalyst droplet and the anisotropic structure of the crystalline NW, and the growth is mainly orchestrated by the triple-phase line (TPL). Despite the intrinsic mismatch between the droplet and the NW symmetries, its discussion has been largely avoided because of its complexity, which has led to the situation when multiple observed phenomena such as NW axial asymmetry or the oscillating truncation at the TPL still lack detailed explanation. The introduction of an electric field control of the droplet has opened even more questions, which cannot be answered without properly addressing three-dimensional (3D) structure and morphology of the NW and the droplet. This work describes the details of electric-field-controlled VLS growth of germanium (Ge) NWs using environmental transmission electron microscopy (ETEM). We perform TEM tomography of the droplet-NW system during an unperturbed growth, then track its evolution while modulating the bias potential. Using 3D finite element method (FEM) modeling and crystallographic considerations, we provide a detailed and consistent mechanism for VLS growth, which naturally explains the observed asymmetries and features of a growing NW based on its crystal structure. Our findings provide a solid framework for the fabrication of complex 3D semiconductor nanostructures with ultimate control over their morphology.
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  • 文章类型: Journal Article
    背景:这项研究调查并比较了疗效,安全,辐射暴露,经皮放射胃造口术(PRG)的两种方式的经济补偿:多层螺旋CT活检模式(MS-CTBM)引导和透视引导(FPRG)。目的是提供有关优化放射学辅助胃造口术程序的见解。
    方法:我们对2018年1月至2024年1月在单个中心进行的PRG程序进行了回顾性分析。根据所使用的成像方式将程序分为两组。我们比较了病人的人口统计,干预参数,并发症发生率,和程序时间。根据瑞士门诊医疗服务的关税结构(TARMED)评估了经济补偿。使用Fisher精确检验和Mann-WhitneyU检验确定统计学差异。
    结果:研究队列包括133例患者:55例MS-CTBM-PRG和78例FPRG。该队列包括35名女性和98名男性,平均年龄64.59岁(±11.91)。在有效剂量的方式之间观察到显着差异(MS-CTBM-PRG:10.95mSv±11.43vs.FPRG:0.169mSv±0.21,p<0.001)和手术时间(MS-CTBM-PRG:41.15min±16.14vs.FPRG:28.71分钟±16.03,p<0.001)。FPRG的主要并发症明显更频繁(10%vs.0%在MS-CTBM-PRG中,p=0.039,φ=0.214)。最初需要较高的单位数的MS-CTBM引导的PRG,以将手术持续时间减少10分钟。财务比较显示,只有4%的MS-CTBM引导的PRG获得了相当于最频繁的可比检查的报销,根据TARMED。
    结论:根据我们的回顾经验,单中心研究,使用MS-CTBM执行PRG,与FPRG相反,尽管主要并发症的发生率较低,但目前在具有挑战性的病例中是合理的。然而,需要进一步精心设计的前瞻性多中心研究来确定疗效,安全,以及这两种模式的成本效益。
    BACKGROUND: This study investigated and compared the efficacy, safety, radiation exposure, and financial compensation of two modalities for percutaneous radiologic gastrostomy (PRG): multislice computed tomography biopsy mode (MS-CT BM)-guided and fluoroscopy-guided (FPRG). The aim was to provide insights into optimizing radiologically assisted gastrostomy procedures.
    METHODS: We conducted a retrospective analysis of PRG procedures performed at a single center from January 2018 to January 2024. The procedures were divided into two groups based on the imaging modality used. We compared patient demographics, intervention parameters, complication rates, and procedural times. Financial compensation was evaluated based on the tariff structure for outpatient medical services in Switzerland (TARMED). Statistical differences were determined using Fisher\'s exact test and the Mann-Whitney U test.
    RESULTS: The study cohort included 133 patients: 55 with MS-CT BM-PRG and 78 with FPRG. The cohort comprised 35 women and 98 men, with a mean age of 64.59 years (±11.91). Significant differences were observed between the modalities in effective dose (MS-CT BM-PRG: 10.95 mSv ± 11.43 vs. FPRG: 0.169 mSv ± 0.21, p < 0.001) and procedural times (MS-CT BM-PRG: 41.15 min ± 16.14 vs. FPRG: 28.71 min ± 16.03, p < 0.001). Major complications were significantly more frequent with FPRG (10% vs. 0% in MS-CT BM-PRG, p = 0.039, φ = 0.214). A higher single-digit number of MS-CT BM-guided PRG was required initially to reduce procedure duration by 10 min. Financial comparison revealed that only 4% of MS-CT BM-guided PRGs achieved reimbursement equivalent to the most frequent comparable examination, according to TARMED.
    CONCLUSIONS: Based on our experience from a retrospective, single-center study, the execution of a PRG using MS-CT BM, as opposed to FPRG, is currently justified in challenging cases despite a lower incidence of major complications. However, further well-designed prospective multicenter studies are needed to determine the efficacy, safety, and cost-effectiveness of these two modalities.
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  • 文章类型: Journal Article
    目的:使用Dense-UNet架构评估基于深度学习的管道,以评估创伤性脑损伤(TBI)后的非对比计算机断层扫描(NCCT)头部扫描的急性颅内出血(ICH)。
    方法:这项回顾性研究是使用原型算法进行的,该算法在TBI背景下评估了502例ICH的NCCT头部扫描。四名委员会认证的放射科医师一致评估了CT扫描,以建立出血存在和ICH类型的参考标准。因此,所有CT扫描由算法和董事会认证的放射科医师独立分析,以评估ICH的存在和类型.此外,对两种方法的诊断时间进行了测定.
    结果:共有405/502例患者出现ICH,分为以下类型:实质内(n=172);脑室内(n=26);蛛网膜下(n=163);硬膜下(n=178);和硬膜外(n=15)。该算法对ICH的评估显示出较高的诊断准确性(91.24%),敏感性为90.37%,特异性为94.85%。为了区分不同的ICH类型,该算法的灵敏度为93.47%,特异性为99.79%,准确率为98.54%。要检测中线偏移,该算法的灵敏度为100%。在处理时间上,与放射科医生的首次诊断时间相比,该算法明显更快(15.37±1.85vs277±14s,p<0.001)。
    结论:一种新颖的深度学习算法可以为未增强CT扫描对ICH的识别和分类提供很高的诊断准确性,结合短处理时间。这有可能帮助和改善放射科医师在NCCT扫描中的ICH评估,尤其是在紧急情况下,当需要时间效率时。
    OBJECTIVE: To evaluate a deep learning-based pipeline using a Dense-UNet architecture for the assessment of acute intracranial hemorrhage (ICH) on non-contrast computed tomography (NCCT) head scans after traumatic brain injury (TBI).
    METHODS: This retrospective study was conducted using a prototype algorithm that evaluated 502 NCCT head scans with ICH in context of TBI. Four board-certified radiologists evaluated in consensus the CT scans to establish the standard of reference for hemorrhage presence and type of ICH. Consequently, all CT scans were independently analyzed by the algorithm and a board-certified radiologist to assess the presence and type of ICH. Additionally, the time to diagnosis was measured for both methods.
    RESULTS: A total of 405/502 patients presented ICH classified in the following types: intraparenchymal (n = 172); intraventricular (n = 26); subarachnoid (n = 163); subdural (n = 178); and epidural (n = 15). The algorithm showed high diagnostic accuracy (91.24%) for the assessment of ICH with a sensitivity of 90.37% and specificity of 94.85%. To distinguish the different ICH types, the algorithm had a sensitivity of 93.47% and a specificity of 99.79%, with an accuracy of 98.54%. To detect midline shift, the algorithm had a sensitivity of 100%. In terms of processing time, the algorithm was significantly faster compared to the radiologist\'s time to first diagnosis (15.37 ± 1.85 vs 277 ± 14 s, p < 0.001).
    CONCLUSIONS: A novel deep learning algorithm can provide high diagnostic accuracy for the identification and classification of ICH from unenhanced CT scans, combined with short processing times. This has the potential to assist and improve radiologists\' ICH assessment in NCCT scans, especially in emergency scenarios, when time efficiency is needed.
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  • 文章类型: Journal Article
    目的:开发并验证基于影像学的模型,以预测导管内乳头状黏液性肿瘤(IPMN)的恶性风险。
    方法:我们回顾性分析了241例IPMN患者的数据,这些患者在术前接受了CT和MRI进行模型开发。囊肿大小,增强壁结节(EMN)的存在和大小,主胰管(MPD)直径,增厚/增强囊肿壁,MPD口径突变伴远端萎缩,和淋巴结病进行评估。使用连续(模型C)或二分变量(模型D)使用这些成像特征创建预测恶性肿瘤风险的多元逻辑回归模型。验证包括内部(n=55)和外部(n=43)数据集。使用受试者工作特征曲线下面积(AUC)评估模型性能,并与基于国际指南的模型(模型F)进行比较。
    结果:模型C确定了年龄,EMN尺寸,MPD直径,淋巴结病是CT的独立预测因子,MRI上EMN的年龄、存在和大小。D型鉴定年龄≥68,囊肿大小≥31mm,EMN≥6mm,MPD≥7mm,淋巴结病是CT的独立预测因子,年龄≥68岁,EMN≥4.5mm,和MRI上的淋巴结肿大。型号C(AUC,0.763-0.899)的性能略优于D型(AUC,0.753-0.912)无统计学意义。模型C和F之间没有观察到显著差异(AUC,0.729-0.952).将模型C与阻塞性黄疸结合使用可改善性能(AUC,0.802-0.941)无统计学意义。
    结论:我们基于成像的模型有效地预测了IPMNs的恶性风险,与国际共识准则相当。
    结论:影像学特征对于预测IPMNs的恶性潜能很重要。我们基于成像的模型可能有助于确定IPMN患者的手术候选资格。
    结论:非侵入性地确定导管内乳头状黏液性肿瘤(IPMNs)的恶性潜能可以做出适当的治疗决策。我们确定了与恶性转化相关的多种影像学特征,并开发了该预测模型。我们的模型在预测IPMNs的恶性潜力方面与国际共识指南具有可比性。
    OBJECTIVE: To develop and validate imaging-based models for predicting the malignancy risk of intraductal papillary mucinous neoplasm (IPMN).
    METHODS: We retrospectively analyzed data from 241 IPMN patients who underwent preoperative CT and MRI for model development. Cyst size, presence and size of the enhancing mural nodule (EMN), main pancreatic duct (MPD) diameter, thickened/enhancing cyst wall, abrupt MPD caliber change with distal atrophy, and lymphadenopathy were assessed. Multiple logistic regression models predicting malignancy risk were created using either continuous (Model C) or dichotomized variables (Model D) using these imaging features. Validation included internal (n = 55) and external (n = 43) datasets. Model performance was assessed using the area under the receiver operating characteristic curve (AUC) and compared with that of the international guideline-based model (Model F).
    RESULTS: Model C identified age, EMN size, MPD diameter, and lymphadenopathy as independent predictors on CT, and age and presence and size of EMN on MRI. Model D identified age ≥ 68, cyst size ≥ 31 mm, EMN ≥ 6 mm, MPD ≥ 7 mm, and lymphadenopathy as independent predictors on CT, and age ≥ 68, EMN ≥ 4.5 mm, and lymphadenopathy on MRI. Model C (AUC, 0.763-0.899) performed slightly better than Model D (AUC, 0.753-0.912) without statistical significance. No significant difference was observed between Models C and F (AUC, 0.729-0.952). Combining Model C with obstructive jaundice improved performance (AUC, 0.802-0.941) without statistical significance.
    CONCLUSIONS: Our imaging-based models effectively predicted the malignancy risk of IPMNs, comparable to international consensus guidelines.
    CONCLUSIONS: Imaging features are important for predicting the malignant potential of IPMNs. Our imaging-based model may help determine surgical candidacy for patients with IPMNs.
    CONCLUSIONS: Non-invasively determining the malignant potential of intraductal papillary mucinous neoplasms (IPMNs) allows for appropriate treatment decision-making We identified multiple imaging features that are associated with malignant transformation and developed models for this prediction. Our model performs comparably with international consensus guidelines in predicting the malignant potential of IPMNs.
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  • 文章类型: Journal Article
    为了证明使用环形阵列超声(US)换能器的可行性,由超声断层成像(UST)引导,用于产生和监测轻度高热(MHTH)。
    设计了计算机模拟和体外实验,以评估环形阵列US换能器产生MHTh和监测温度变化的功效。在一系列的计算机模拟研究中,我们比较了环形阵列US换能器在不同频率下发射所产生的声学焦点轮廓,并进一步研究了UST引导在实施像差校正以增强焦点轮廓方面的有效性。体外实验评估了使用环形阵列US换能器产生和维持MHTh的能力以及使用UST监测温度变化的准确性。
    模拟表明,环形阵列US换能器实现了对称和局部声学聚焦。在异质组织模型中,环形阵列US换能器通过在UST的指导下实施像差校正,实现了出色的声学聚焦。体外实验证明了环形阵列US换能器在平均117±18s的组织模拟体模中产生MHTh并随后维持MHTh的能力。最后,AringarrayUStransducerusedUSTtotracktemperaturechangesinapreferredwater-filledinclusionwhileitpassivelycooledfrom45°Cto25°C,最大误差为0.58°C。
    环形阵列US换能器可以无创地产生和监测MHTh,克服了当前临床系统的许多局限性。换能器的闭合几何形状对于声聚焦和UST引导是最佳的,可以改善异质介质中的像差校正。利用UST测温与相同的环形阵列US换能器将允许实现图像引导,温度控制,全声MHTH系统。
    UNASSIGNED: To demonstrate the feasibility of using a ring array ultrasound (US) transducer, guided by ultrasound tomography (UST), for generating and monitoring mild hyperthermia (MHTh).
    UNASSIGNED: In silico and in vitro experiments were designed to evaluate the efficacy of a ring array US transducer for generating MHTh and monitoring changes in temperature. In a series of in silico studies, we compared the acoustic focal profiles produced by a ring array US transducer transmitting at different frequencies and further investigated the effectiveness of UST-guidance in implementing aberration correction to enhance the focal profile. In vitro experiments evaluated the capability of using a ring array US transducer to generate and maintain MHTh and the accuracy of using UST to monitor temperature changes.
    UNASSIGNED: The simulations demonstrated that a ring array US transducer achieves symmetrical and localized acoustic focusing. In a heterogenous tissue model, a ring array US transducer achieved a superior acoustic focus by implementing aberration correction with guidance from UST. In vitro experiments demonstrated the capability of a ring array US transducer to generate MHTh in a tissue-mimicking phantom in an average of 117 ± 18 s and subsequently maintain MHTh. Lastly, a ring array US transducer utilized UST to track temperature changes in a preheated water-filled inclusion while it passively cooled from 45 °C to 25 °C, with a maximum error of 0.58 °C.
    UNASSIGNED: A ring array US transducer can noninvasively generate and monitor MHTh, overcoming many limitations of current clinical systems. The closed geometry of the transducer is optimal for acoustic focusing and UST-guidance allows for improved aberration correction in a heterogenous medium. Utilizing UST thermometry with the same ring array US transducer will allow for implementing an image-guided, temperature-controlled, all-acoustic MHTh system.
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  • 文章类型: Journal Article
    在这项试点研究中,我们研究了手持式超声引导光声(US-PA)成像探头用于分析接受保乳手术(BCS)的女性患者的离体乳腺标本的实用性.我们的目的是评估US-PA在检测生化标志物如胶原蛋白方面的潜力,脂质,和血红蛋白,并将这些发现与常规成像方式(乳房X线照相术,超声)和组织病理学结果,特别是在不同的乳房密度。从接受BCS的平均年龄为59.7±9.5岁的女性患者中获得了12个离体乳腺标本。使用手持式US-PA探针在所有边缘700至1100nm之间照射组织,并分析胶原蛋白。脂质,和血红蛋白分布。将获得的结果与常规成像和组织病理学评估进行比较。我们的研究结果表明,脂质强度和分布随着乳腺密度的增加而降低,而胶原蛋白表现出相反的趋势。这些观察结果与常规成像和组织病理学分析一致。此外,癌变和正常乳腺组织之间的胶原强度显着不同(P<0.001),表明其作为跨各种乳房疾病的风险分层的额外生物标志物的潜力。研究结果表明,PA生化信息的综合评估,如胶原蛋白和脂质含量,叠加灰度超声检查结果可以帮助区分正常和恶性乳腺疾病,以及协助BCS利润率评估。这强调了US-PA成像作为增强乳腺癌诊断和治疗的宝贵工具的潜力。为现有的成像方式和组织病理学提供补充信息。
    In this pilot study, we investigated the utility of handheld ultrasound-guided photoacoustic (US-PA) imaging probe for analyzing ex-vivo breast specimens obtained from female patients who underwent breast-conserving surgery (BCS). We aimed to assess the potential of US-PA in detecting biochemical markers such as collagen, lipids, and hemoglobin, and compare these findings with routine imaging modalities (mammography, ultrasound) and histopathology results, particularly across various breast densities. Twelve ex-vivo breast specimens were obtained from female patients with a mean age of 59.7 ± 9.5 years who underwent BCS. The tissues were illuminated using handheld US-PA probe between 700 and 1100 nm across all margins and analyzed for collagen, lipids, and hemoglobin distribution. The obtained results were compared with routine imaging and histopathological assessments. Our findings revealed that lipid intensity and distribution decreased with increasing breast density, while collagen exhibited an opposite trend. These observations were consistent with routine imaging and histopathological analyses. Moreover, collagen intensity significantly differed (P < 0.001) between cancerous and normal breast tissue, indicating its potential as an additional biomarker for risk stratification across various breast conditions. The study results suggest that a combined assessment of PA biochemical information, such as collagen and lipid content, superimposed on grey-scale ultrasound findings could aid in distinguishing between normal and malignant breast conditions, as well as assist in BCS margin assessment. This underscores the potential of US-PA imaging as a valuable tool for enhancing breast cancer diagnosis and management, offering complementary information to existing imaging modalities and histopathology.
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  • 文章类型: Journal Article
    扩散张量磁共振电阻抗断层扫描(DT-MREIT)和无电极电导率张量成像(CTI)是两种新兴的模式,可以通过假设离子迁移率和水扩散背后的相似特性来量化低频组织各向异性电导率特性。虽然这两种方法在估计神经调制场或制定用于电源成像的正向模型方面都有潜在的应用。两种模式的直接比较尚未在体外或体内进行。因此,这项研究的目的是测试这两种模式的等效性。我们使用DT-MREIT和CTI协议扫描了组织体模和人类受试者的头部,并重建了电导率张量和有效的低频电导率。我们发现通过每种技术恢复的灰质和白质电导率在0.05S/m内相等。DT-MREIT和CTI都需要多个处理步骤,我们进一步评估了每个因素对重建的影响,并评估了不同的测量机制可能导致两种方法之间的差异的程度。最后,我们讨论了使用这些技术测量电导率的光谱模型的含义。该研究进一步确立了CTI作为测量低频电导率特性的无电极非侵入性方法的可信度。
    Diffusion tensor magnetic resonance electrical impedance tomography (DT-MREIT) and electrodeless conductivity tensor imaging (CTI) are two emerging modalities that can quantify low-frequency tissue anisotropic conductivity properties by assuming similar properties underlie ionic mobility and water diffusion. While both methods have potential applications to estimating neuro-modulation fields or formulating forward models used for electrical source imaging, a direct comparison of the two modalities has not yet been performed in-vitro or in-vivo. Therefore, the aim of this study was to test the equivalence of these two modalities. We scanned a tissue phantom and the head of human subject using DT-MREIT and CTI protocols and reconstructed conductivity tensor and effective low frequency conductivities. We found both gray and white matter conductivities recovered by each technique were equivalent within 0.05 S/m. Both DT-MREIT and CTI require multiple processing steps, and we further assess the effects of each factor on reconstructions and evaluate the extent to which different measurement mechanisms potentially cause discrepancies between the two methods. Finally, we discuss the implications for spectral models of measuring conductivity using these techniques. The study further establishes the credibility of CTI as an electrodeless non-invasive method of measuring low frequency conductivity properties.
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