Detection of prostate cancer with multiparametric MRI utilizing the anatomic structure of the prostate

Multiparametric magnetic resonance imaging (mpMRI), which combines traditional anatomic and newer quantitative MRI methods, has been shown to result in improved voxel‐wise classification of prostate cancer as compared with any single MRI parameter. While these results are promising, substantial heterogeneity in the mpMRI parameter values and voxel‐wise prostate cancer risk has been observed both between and within regions of the prostate. This suggests that classification of prostate cancer can potentially be improved by incorporating structural information into the classifier. In this paper, we propose a novel voxel‐wise classifier of prostate cancer that accounts for the anatomic structure of the prostate by Bayesian hierarchical modeling, which can be combined with post hoc spatial Gaussian kernel smoothing to account for residual spatial correlation. Our proposed classifier results in significantly improved area under the ROC curve (0.822 vs 0.729, P < .001) and sensitivity corresponding to 90% specificity (0.599 vs 0.429, P < .001), compared with a baseline model that does not account for the anatomic structure of the prostate. Furthermore, the classifier can also be applied on voxels with missing mpMRI parameters, resulting in similar performance, which is an important practical consideration that cannot be easily accommodated using regression‐based classifiers. In addition, our classifier achieved high computational efficiency with a closed‐form solution for the posterior predictive cancer probability.     

四种影像学检查在诊断前列腺癌中的应用评价

目的探讨4种影像学检查在前列腺癌诊断中的应用价值。方法对165例疑诊前列腺癌患者的经腹超声、经直肠超声、CT平扫及强化、MRI平扫及强化的影像学检查资料进行回顾性分析,所有患者均经直肠超声引导下穿刺取得病理结果,总结每项影像检查对前列腺肿瘤的诊断方法及影像学综合诊断过程中应注意的问题。结果经腹超声、经直肠超声、CT平扫及强化、MRI平扫及强化、敏感度分别为70.0%、85.7%、64.3%、97.1%,4者结合的诊断准确率为100%。结论多项影像联合检查对前列腺癌的早期发现、确诊具有重要帮助;对临床康复治疗方案的选择及变更有重要指导意义。     

A randomized trial of early detection of clinically significant prostate cancer (ProScreen): study design and rationale

The current evidence of PSA-based prostate cancer screening shows a reduction in cause-specific mortality, but with substantial overdiagnosis. Recently, new developments in detection of clinically relevant prostate cancer include multiple kallikreins as biomarkers besides PSA, and multiparametric magnetic resonance imaging (mpMRI) for biopsy decision. They offer opportunities for improving the outcomes in screening, particularly reduction in overdiagnosis and higher specificity for potentially lethal cancer. A population-based randomized screening trial will be started, with 67,000 men aged 55–67 years at entry. A quarter of the men will be allocated to the intervention arm, and invited to screening. The control arm will receive no intervention. All men in the screening arm will be offered a serum PSA determination. Those with PSA of 3 ng/ml or higher will have an additional multi-kallikrein panel and those with indications of increased risk of clinically relevant prostate cancer will undergo mpMRI. Men with a malignancy-suspect finding in MRI are referred to targeted biopsies. Screening interval is 6 years for men with baseline PSA < 1.5 ng/ml, 4 years with PSA 1.5–3.0 and 2 years if initial PSA > 3. The main outcome of the trial is prostate cancer mortality, with analysis at 10 and 15 years. The statistical power is sufficient for detecting a 28% reduction at 10 years and 22% at 15 years. The proposed study has the potential to provide the evidence to justify screening as a public health policy if mortality benefit can be sustained with substantially reduced overdiagnosis.     

磁共振波谱成像对前列腺癌诊断价值的研究

目的 探讨磁共振波谱(MRS)在前列腺癌及良性前列腺增生诊断中的价值.方法 回顾性分析经病理证实的55例(良性前列腺增生36例,前列腺癌19例)患者的临床资料、磁共振成像(MRI)和MRS所见.检测代谢产物包括枸橼梭盐(Cit)、胆碱复合物(Cho)、肌酸(Cre)的波谱图.MRI观察前列腺的大小、信号特点、病变位置及肿瘤侵犯程度.MRS观察Cit、Cho、Cre的峰值及(Cho+Cre)/Cit.结果 MRI对前列腺癌诊断的灵敏度、特异度、准确率分别为78.9%(15/19)、66.7%(24/36)、70.9%(39/5).MRI+MRS分别为84.2%(16/19)、88.9%(32/36)、87.3%(48/55). MRI与MRI+MRS两种方法在诊断前列腺癌的灵敏度、特异度、准确率方面差异均有统计学意义(P<0.05).结论 无创的MRS可以提示病变部位的代谢及其成分的改变,结合影像学表现有助于对良性前列腺增生和前列腺癌的鉴别诊断.     

Prediction of out-of-field recurrence after chemoradiotherapy for cervical cancer using a combination model of clinical parameters and magnetic resonance imaging radiomics: a multi-institutional study of the Japanese Radiation Oncology Study Group

We retrospectively assessed whether magnetic resonance imaging (MRI) radiomics combined with clinical parameters can improve the predictability of out-of-field recurrence (OFR) of cervical cancer after chemoradiotherapy. The data set was collected from 204 patients with stage IIB (FIGO: International Federation of Gynecology and Obstetrics 2008) cervical cancer who underwent chemoradiotherapy at 14 Japanese institutes. Of these, 180 patients were finally included for analysis. OFR-free survival was calculated using the Kaplan–Meier method, and the statistical significance of clinicopathological parameters for the OFR-free survival was evaluated using the log-rank test and Cox proportional-hazards model. Prediction of OFR from the analysis of diffusion-weighted images (DWI) and T2-weighted images of pretreatment MRI was done using the least absolute shrinkage and selection operator (LASSO) model for engineering image feature extraction. The accuracy of prediction was evaluated by 5-fold cross-validation of the receiver operating characteristic (ROC) analysis. Para-aortic lymph node metastasis (p = 0.003) was a significant prognostic factor in univariate and multivariate analyses. ROC analysis showed an area under the curve (AUC) of 0.709 in predicting OFR using the pretreatment status of para-aortic lymph node metastasis, 0.667 using the LASSO model for DWIs and 0.602 using T2 weighted images. The AUC improved to 0.734 upon combining the pretreatment status of para-aortic lymph node metastasis with that from the LASSO model for DWIs. Combining MRI radiomics with clinical parameters improved the accuracy of predicting OFR after chemoradiotherapy for locally advanced cervical cancer.     

磁共振DWI结合T2加权成像诊断前列腺癌侵犯精囊腺

目的：探讨分别应用T2WI、DWI以及综合应用这2种成像序列对前列腺癌（PCa）侵犯精囊腺（SVI）的诊断价值。方法：对50例PCa患者行MR前列腺常规和DWI扫描,所有患者经前列腺癌根治术证实,其中21例伴有SVI。分析PCa癌灶、SVI和正常精囊腺（SV）的MRI表现,比较其ADC值。采用5分制评分,将所得结果与病理结果对照,采用SPSS11.5分别绘制受试者工作特征曲线（ROC）,分析比较各组方法诊断的敏感度和特异度。结果：PCa癌灶、SVI和SV的ADC值分别为（0.940±0.122）×10^-3 mm2/s、（1.025±0.186）×10^-3 mm2/s和（2.798±0.248）×10^-3 mm2/s,SVI的ADC值明显低于SV（P〈0.05）,而PCa癌灶和SVI的ADC值之间无明显差异（P=0.20）。分别应用T2WI和DWI诊断SVI的ROC曲线下面积（AUC）明显低于联合应用2种成像方法（P〈0.05）。结论：SVI的ADC值明显低于SV;联合应用2种成像序列诊断SVI优于单独使用T2WI或DWI。     

MRI在鼻咽癌放疗患者疗效评估中的应用

目的探讨磁共振成像(MRI)在鼻咽癌放疗患者疗效评估中的应用。方法选取2014年3月至2019年3月就诊于我院的88例疑似鼻咽癌患者,均行MRI检查。以病理活检结果为金标准,计算MRI检查的准确度、特异度、灵敏度,并比较放疗前后的原发病灶及转移淋巴结的表观扩散系数(ADC)值和肿瘤面积。结果 88例疑似鼻咽癌患者中,病理活检确诊71例;以病理活检结果为金标准,MRI诊断的准确度为80.68%,灵敏度为87.32%,特异度为52.94%。放疗后,原发病灶及颈部转移淋巴结节的ADC值均显著高于放疗前,肿瘤面积显著小于放疗前,差异有统计学意义(P<0.05)。结论 MRI诊断鼻咽癌的准确度、灵敏度较高,MRI扩散加权成像技术可有效用于鼻咽癌放疗效果的评估中,快速显示放疗前后的肿瘤变化。     

核素亲肿瘤显像、CT及MRI检查诊断鼻咽癌放疗后复发的价值分析

目的评价99mTc-M IB I亲肿瘤显像、CT及MR I检查诊断鼻咽癌放疗后复发的价值。方法78例鼻咽癌放疗后患者经病理活检和随访证实局部复发38例,局部纤维化40例。所有患者行99mTc-M IB I亲肿瘤显像、CT及MR I检查,分析3种方法的诊断效能。结果99mTc-M IB I亲肿瘤显像灵敏度(73.7%)低于CT(94.7%)和MR I(92.1%),但特异性(92.5%)明显高于CT(62.5%)和MR I(67.5%)。3种方法诊断的准确率比较差异无统计学意义。3种方法联合诊断的灵敏度、特异性和准确率分别为97.4%、95%和96.2%。结论99mTc-M IB I亲肿瘤显像诊断鼻咽癌放疗后复发具有较高的特异性,可以弥补CT、MR I检查假阳性率高的缺点,3种方法联合可明显提高诊断的准确性。     

MRI动态增强、^18F-FDG-PET/CT显像对鼻咽癌放疗后复发与纤维化早期诊断的临床价值

目的：分析MRI动态增强与18F-FDG-PET/CT在鼻咽癌放疗后早期鉴别诊断复发以及纤维化中的价值。方法：选取2005年8月-2011年8月收治的鼻咽癌患者中,放疗后疑出现复发的患者37例,均分别行MRI动态增强与18F-FDG-PET/CT检查,对比两种检测方式的敏感性、特异性、准确性以及检测费用。结果：MRI检测敏感性93.8%,特异性95.5%,准确性94.9%;PET/CT检测敏感性87.5%,特异性91.3%,准确性90.2%;MRI检测敏感性更高（P〈0.05）;在特异性和准确性上差别不显著,且在检测费用上比较差异无统计学意义（P〉0.05）。结论：MRI动态增强与18F-FDG-PET/CT在鼻咽癌放疗后早期鉴别诊断复发以及纤维化中均有一定价值,但同时均有局限性;联合应用利于诊断价值的提高。     

Small area estimation of receiver operating characteristic curves for ordinal data under stochastic ordering

There has been a recent increase in the diagnosis of diseases through radiographic images such as x-rays, magnetic resonance imaging, and computed tomography. The outcome of a radiological diagnostic test is often in the form of discrete ordinal data, and we usually summarize the performance of the diagnostic test using the receiver operating characteristic (ROC) curve and the area under the curve (AUC). The ROC curve will be concave and called proper when the outcomes of the diagnostic test in the actually positive subjects are higher than in the actually negative subjects. The diagnostic test for disease detection is clinically useful when a ROC curve is proper. In this study, we develop a hierarchical Bayesian model to estimate the proper ROC curve and AUC using stochastic ordering in several domains when the outcome of the diagnostic test is discrete ordinal data and compare it with the model without stochastic ordering. The model without stochastic ordering can estimate the improper ROC curve with a nonconcave shape or a hook when the true ROC curve of the population is a proper ROC curve. Therefore, the model with stochastic ordering is preferable over the model without stochastic ordering to estimate the proper ROC curve with clinical usefulness for ordinal data.     

Receiver operator characteristic (ROC) analysis without truth

Receiver operator characteristic (ROC) analysis, the preferred method of evaluating diagnostic imaging tests, requires an independent assessment of the true state of disease, which can be difficult to obtain and is often of questionable accuracy. A new method of analysis is described which does not require independent truth data and which can be used when several accurate tests are being compared. This method uses correlative information to estimate the underlying model of multivariate normal distributions of disease-positive and disease-negative patients. The method is shown to give results equivalent to conventional ROC analysis in a comparison of computed tomography, radionuclide scintigraphy, and magnetic resonance imaging for liver metastasis. When independent truth is available, the method can be extended to incorporate truth data or to evaluate the consistency of the truth data with the imaging data.     

多参数MRI成像技术用于前列腺癌病理和分期的预测价值研究

目的 评价多参数MRI成像技术用于前列腺癌病理和分期的预测价值。方法 以2016—2021年收治的80例前列腺癌患者作为研究对象，全部患者均接受多参数MRI成像扫描。以根治性前列腺切除术后病理切片结果作为金标准，评价多参数MRI成像用于显著性前列腺癌、包膜外侵犯、主要病灶部位和淋巴结转移的预测价值。结果 多参数MRI用于鉴别显著性前列腺癌的敏感性为96%、特异性为60%、阳性预测值为97.3%、阴性预测值为50%；鉴别主要病变与根治性前列腺切除术后病理切片结果一致性为75%；检测包膜外侵犯敏感性为40%、特异性为91.4%、阳性预测值为85.7%、阴性预测值为54.2%；检测淋巴结转移的准确性为16.7%。结论 多参数MRI成像用于鉴别显著性前列腺癌的敏感性和阳性预测值及检测前列腺癌主要病变的准确度均较高，对于制定前列腺癌治疗方案、评估预后等均具有重要价值。     

磁共振成像在肺癌放疗肿瘤区确认中的价值

目的：探讨在肿瘤界限不明的肺癌放疗中应用磁共振常规扫描联合扩散加权成像对确定照射范围的作用。方法：选取伴有阻塞性肺炎（6例）或肺不张（24例）的肺癌患者30例。放疗前分别采用1.5 T和3.0 T磁共振成像系统各检查患者15例,DWI在1.5 T和3.0 T扫描中扩散加权系数（b值）分别选择为600 s/mm2和1 000 s/mm2。根据MRI影像判断勾画放疗的肿瘤区（GTV）。结果：3.0 T磁共振成像对比度及信噪比高,判断病变良恶性的价值更大,但超高场强易产生空间几何扭曲伪影。而1.5 T磁共振成像系统中的几何变形相对少,但判断病变良恶性的价值不如3.0 T。MRI可协助明确判断GTV范围的占63.3%。结论：对肺癌患者放疗难以判断GTV界限时,磁共振平扫联合DWI有助于进一步明确靶区的勾画范围,采用1.5 T的磁共振成像系统效果更佳。     

MRI在前列腺癌诊断中的应用

目的：探讨MRI在前列腺癌诊断中的临床价值。方法：回顾多种MRI技术（常规EMR平扫与增强、灌注、弥散以及波谱成像技术）在前列腺癌诊断中的应用,比较各种方法在诊断前列腺癌中的优势。结果：多MRI技术的综合应用不仅有利于前列腺癌的检出和定位,有助于前列腺癌的诊断及鉴别,还能提供有关前列腺癌的生长、预后及转移信息。     

三种统计分析方法在基因表达谱数据中的比较研究

目的比较SCAD-支持向量机、支持向量机和弹性网三种方法对基因表达谱数据的变量筛选和预测判别能力。方法根据设置的参数生成不同条件的基因表达谱模拟数据和实际数据,利用FDR、一致性错误率和ROC曲线下面积(AUC值)从三个方面评价三种方法的变量筛选和预测判别能力。结果模拟实验显示在差异变量数不变的情况下,随着差异变量间相关系数的增加,三种方法建立模型的变量筛选和预测判别能力均提高;当差异变量间相关系数不变时,随着差异变量数目的增加,SCAD-支持向量机和弹性网方法的变量筛选和预测判别能力均呈下降趋势,而支持向量机呈现提高趋势。结论 SCAD-支持向量机不仅改善了支持向量机不能直接进行变量筛选的不足同时提高了模型的精度以及判别的准确性。综合来看SCAD-支持向量机的变量筛选和预测判别能力更优,处理变量间有高度相关性的基因表达谱数据时可以获得更高的预测精度和更稳定的模型估计。     

多参数磁共振成像鉴别颈部淋巴结良恶性的研究

目的:探讨多参数磁共振成像(mp MRI)在鉴别颈部淋巴结良恶性中的应用价值。方法:选取在医院行MR检查初诊颈部淋巴结病变的34例患者,将其经手术、穿刺病理或随访证实的95枚颈部淋巴结依据淋巴结病理结果分为良性淋巴结组(51枚)和恶性淋巴结组(44枚)。分析颈部良、恶性淋巴结MRI平扫影像特征、表观弥散系数(ADC)值及动态增强扫描时间-信号曲线类型、达峰时间等指标间的差异,绘制受试者工作特征(ROC)曲线,比较不同检查技术间的敏感性、特异性及ROC曲线下面积(AUC)。结果:恶性淋巴结组淋巴结平均长径、短径均大于良性淋巴结组,差异有统计学意义(t=2.287,t=2.637;P<0.05);恶性淋巴结组平均ADC值低于良性淋巴结组,差异有统计学意义(t=2.702,P<0.05);颈部良性淋巴结时间-信号曲线多为B型,恶性淋巴结则以A型为主;颈部良性淋巴结组的平均达峰时间明显早于恶性淋巴结组,差异有统计学意义(t=40.983,P<0.05)。mp MRI鉴别颈部淋巴结良、恶性的敏感性及特异性均高于弥散加权成像(DWI)、动态增强扫描序列。AUC的mp MRI>动态增强扫描>DWI成像,三者间差异有统计学意义(Z=5.247,P<0.001)。结论:mp MRI能够提供更加全面的形态学及血流动力学等信息,综合分析能够提高颈部淋巴结定性诊断的准确性。     

基于SMOTE算法与机器学习的老年人健康素养预测研究

目的 探讨合成少数类过采样技术(SMOTE)结合机器学习模型在老年人是否具备健康素养预测评估中的应用。方法 利用单因素筛选从资料中筛选出与是否具备健康素养有关联的变量;以筛选出的变量作为输入变量,以是否具备健康素养为结局变量,分别在经SMOTE算法处理前后的数据集中建立logistic回归模型、随机森林和SVM模型,通过受试者工作特征曲线(ROC)来评价模型性能。结果 Logistic回归、随机森林和SVM在SMOTE算法处理前的测试集中的准确率分别为0.833、0.600和0.636,3种模型的ROC曲线下面积(AUC)分别为0.723、0.815和0.728;在SMOTE算法处理后的测试集中的准确率分别为0.936、0.908和0.890,3种模型的AUC分别为0.896、0.944和0.897。结论 随机森林模型在老年人是否具备健康素养的预后评估中具有较高的应用价值。     

核磁共振成像诊断儿童髓母细胞瘤的准确性及影像学特征分析

目的 分析核磁共振成像(MRI)诊断儿童髓母细胞瘤的准确性及影像学特征.方法 回顾性分析天津市环湖医院2018年1月-2021年3月期间收取的43例疑似为髓母细胞瘤患儿的临床资料,具有完整的CT、MRI检查资料,以手术病理学诊断作为金标准,统计两种技术的诊断价值,分析其影像学特征.结果 MRI检测髓母细胞瘤检出率(93...     

Prediction of radiation pneumonitis with machine learning using 4D-CT based dose-function features

In this article, we highlight the fundamental importance of the simultaneous use of dose-volume histogram (DVH) and dose-function histogram (DFH) features based on functional images calculated from 4-dimensional computed tomography (4D-CT) and deformable image registration (DIR) in developing a multivariate radiation pneumonitis (RP) prediction model. The patient characteristics, DVH features and DFH features were calculated from functional images by Hounsfield unit (HU) and Jacobian metrics, for an RP grade ≥ 2 multivariate prediction models were computed from 85 non-small cell lung cancer patients. The prediction model is developed using machine learning via a kernel-based support vector machine (SVM) machine. In the patient cohort, 21 of the 85 patients (24.7%) presented with RP grade ≥ 2. The median area under curve (AUC) was 0.58 for the generated 50 prediction models with patient clinical features and DVH features. When HU metric and Jacobian metric DFH features were added, the AUC improved to 0.73 and 0.68, respectively. We conclude that predictive RP models that incorporate DFH features were successfully developed via kernel-based SVM. These results demonstrate that effectiveness of the simultaneous use of DVH features and DFH features calculated from 4D-CT and DIR on functional image-guided radiotherapy.     

磁共振SE-EPI-DWI成像技术诊断中耳胆脂瘤及其常见颅脑并发症的研究

目的:研究磁共振自旋回波-回波平面成像-弥散加权成像(SE-EPI-DWI)技术在中耳胆脂瘤及其常见颅脑并发症诊断中的应用.方法:选择医院收治的疑似中耳胆脂瘤并均经病理检查的82例患者,根据病理检查结果将其分为胆脂瘤组(55例)和非胆脂瘤组(27例).患者术前均行耳部常规MRI及SE-EPI-DWI检查,分析SE-EP...