全文获取类型
收费全文 | 499篇 |
免费 | 67篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 7篇 |
妇产科学 | 2篇 |
基础医学 | 13篇 |
临床医学 | 87篇 |
内科学 | 85篇 |
皮肤病学 | 3篇 |
神经病学 | 36篇 |
特种医学 | 109篇 |
外科学 | 68篇 |
综合类 | 28篇 |
药学 | 11篇 |
中国医学 | 1篇 |
肿瘤学 | 114篇 |
出版年
2023年 | 18篇 |
2022年 | 23篇 |
2021年 | 35篇 |
2020年 | 33篇 |
2019年 | 31篇 |
2018年 | 25篇 |
2017年 | 15篇 |
2016年 | 18篇 |
2015年 | 18篇 |
2014年 | 31篇 |
2013年 | 31篇 |
2012年 | 23篇 |
2011年 | 41篇 |
2010年 | 23篇 |
2009年 | 27篇 |
2008年 | 27篇 |
2007年 | 20篇 |
2006年 | 22篇 |
2005年 | 20篇 |
2004年 | 17篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 13篇 |
1999年 | 11篇 |
1998年 | 6篇 |
1997年 | 16篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有574条查询结果,搜索用时 15 毫秒
1.
目的 观察18F-FDG PET/CT影像组学判断乳腺癌人表皮生长因子受体2(HER2)表达状态的价值。方法 纳入100例乳腺癌患者,包括HER2(+)组28例、HER2(-)组72例,比较组间PET/CT参数,包括病灶最大标准摄取值(SUVmax)及其标准差(SD)、平均标准摄取值(SUVmean)及肿瘤代谢体积的差异。于标准化后的PET图像中手动分割病灶ROI,获取其影像组学特征,根据降维后的影像组学特征及其系数的线性加权获得病灶影像组学风险评分(RRS);针对差异有统计学意义的指标绘制受试者工作特征曲线,计算曲线下面积(AUC),评价其判断乳腺癌患者HER2状态的效能。采用Bootstrap 1000重复抽样进行内部验证,计算校正AUC,并以DeLong检验比较。以决策曲线分析评价患者净获益情况。结果 HER2(+)组病灶SUVmax、SUVmean及SD均大于HER2(-)组(P均<0.05)。共获取704个影像组学特征,经筛选最终获得10个非零系数的特征用于计算RRS,HER2(+)组RRS大于HER2(-)组(P<0.001)。以RRS判断乳腺癌患者HER2状态的AUC大于病灶SUVmax、SUVmean及SD (P均<0.05),其诊断敏感度为78.57%、特异度为77.78%。决策曲线分析结果表明,RRS可在较大概率阈值范围内带给患者更多净获益。结论 18F-FDG PET/CT影像组学用于判断乳腺癌HER2状态具有一定价值。 相似文献
2.
3.
18F-FDG PET/CT影像组学可通过自动、高通量方法自PET/CT图像中提取大量定量特征。应用人工智能和机器学习技术进一步推动了18F-FDG PET/CT影像组学在恶性肿瘤预后研究的进展,有望更好地指导临床管理恶性肿瘤患者。本文对18F-FDG PET/CT影像组学用于评估常见恶性肿瘤预后进展进行综述。 相似文献
4.
5.
《Neuro-Chirurgie》2021,67(6):579-586
BackgroundLiponeurocytoma is an uncommon tumor of the central nervous system. It is very rare for this tumor to originate within the lateral ventricle. In the context of the rarity of this tumor entity, this review article aims to summarize the clinical, radiological, and pathological features of lateral ventricular liponeurocytoma to facilitate its diagnosis and management.MethodsHere, we conduct a systematic literature review using the Pubmed, Scopus, and Cochrane Library database for all cases of lateral ventricular liponeurocytoma. A case illustration complements this review.ResultsThe described cases from 1997 onward include 14 cases that have been published in full papers in the English literature. Six additional cases are reported in short English abstracts in full non-English papers, and one case was described in a central neurocytoma report. There is a definite male predominance of 70% (14 male) and a mean age of 37 years (range 24–62). Heterogenous enhancement and signals in magnetic resonant images (MRI) are the radiological characteristics. In all reported cases, the presence of lipocytes and fat vacuoles is considered the paramount histopathological feature. Total surgical resection was achieved in 80% (12 out of 15) of the cases. Only two cases (including ours) received radiation therapy. Recurrence was seen in two patients during follow-up that was treated by radiation therapy in one and surgery in the other. The proliferation index is mostly below 5% in all cases, with the Ki-67 range between < 1% to 10%.ConclusionsLateral ventricular liponeurocytoma has been treated effectively by surgical resection in a limited number of cases. The decision for radiation therapy is based on a high proliferation index and tumor recurrence. 相似文献
6.
目的 观察18F-AlF-NOTA-octreotide(18F-OCT)联合18F-FDG PET/CT显像用于神经内分泌瘤(NET)的临床价值。方法 回顾性分析21例同期接受18F-OCT和18F-FDG PET/CT显像并经病理学证实的NET患者,其中7例已接受原发瘤根治性切除术、2例原发灶不明;根据2010年WHO分级标准,将12例明确存在原发瘤者分为中/低级别组9例和高级别组3例,对比原发瘤及转移灶在2种显像中的阳性比例、摄取水平及治疗后影像学变化。结果 原发瘤大小与18F-FDG最大标准摄取值(SUVmax)显著相关(r=0.731,P<0.05),但与18F-OCT无明显相关(r=0.311,P>0.05)。中/低级别组9例原发瘤中,8例18F-OCT显像阳性,SUVmax中位数为33.80(6.10,56.55);7例18F-FDG显像阳性,SUVmax中位数3.80(1.40,8.80)(Z=-2.345,P<0.05)。高级别组3例原发瘤中,18F-FDG检出3例,18F-OCT 2例。18F-OCT联合18F-FDG PET/CT显像检测转移灶阳性比例高于单一。追踪观察1例胰腺NET术后肝脏多发转移患者,奥曲肽对其18F-OCT显像阳性病灶取得良好疗效。结论 18F-OCT联合18F-FDG PET/CT显像可作为检测NET的辅助手段,并有望用于预估疗效。 相似文献
7.
前体淋巴细胞恶性肿瘤以T细胞来源为主,而B淋巴母细胞性淋巴瘤(B-lymphoblastic lymphoma,B-LBL)仅占约10%,常累及皮肤或骨骼,纵隔受累少见。B-LBL与B淋巴母细胞白血病(B-acute lymphoblastic leukemia,B-ALL)可归为一类,骨髓中淋巴母细胞比例≥25%时为B-ALL,比例在5%~25%时应诊断为B-LBL骨髓浸润[1]。肾脏淋巴瘤少见,且多为继发性。本研究观察B-LBL/ALL肾脏浸润的18 F-FDG PET/CT表现。 相似文献
8.
Soft tissue sarcomas (STS) are rare tumours presenting as soft tissue lumps. Ultrasound is often the primary modality for the initial assessment, with MRI the mainstay for lesion characterisation. PET/CT along with other emerging MRI sequences are used in certain situations as an adjunct and problem solving tool in STS staging and assessment of disease recurrence. Recent advances include the promise of whole body MRI, hybrid PET/MRI, diffusion weighted imaging, dynamic contrast enhanced MRI and advances in artificial intelligence. This article discusses current concepts in extremity STS imaging and highlights recent advances. 相似文献
9.
目的:探讨原发性肠淋巴瘤(PIL)的18F-氟代葡萄糖(FDG)PET/CT的影像学表现。方法收集2005年1月~2016年1月间23例原发性肠淋巴瘤患者的临床及18F-FDG PET/CT资料,对病灶的分布、形态、代谢表现进行回顾性分析及总结。结果23例PIL以弥漫性大B细胞淋巴瘤(DLBCL)与肠病相关性T细胞淋巴瘤(EATL)为主要病理学类型,分别占47.8%和43.4%。回肠、回盲部及升结肠为PIL常见发病部位,共占57.0%。所有42个肠道病灶均呈18F-FDG浓聚,最大标准摄取值(SUVmax)为15.2±8.1(3.6~33.7),其中DLBCL组与EATL组间SUVmax差异无统计学意义,(t=1.851,P=0.073)。肠壁呈弥漫性均匀性或不均匀性增厚是PIL肠道病灶的主要形态学表现,DLBCL组与EATL组在肠道病灶形态学上的差异无统计学意义(χ2=0.426,P=0.514)。26.2%的患者存在病灶处肠腔瘤样扩张,DLBCL组其发生率高于EATL组(χ2=8.101,P=0.004)。56.5%患者存在腹部淋巴结侵犯,30.4%见少量腹腔积液。结论原发性肠淋巴瘤在18F-FDG PET/CT显像上具有一定特点,同时,18F-FDG PET/CT是检测原发性肠淋巴瘤的肠内外病灶并显示该病影像学征象的灵敏影像学技术,对该病的诊断有重要价值。 相似文献
10.
《JACC: Cardiovascular Imaging》2020,13(4):1008-1017
ObjectivesThis study determined whether in vivo positron emission tomography (PET) of arterial inflammation (18F-fluorodeoxyglucose [18F-FDG]) or microcalcification (18F-sodium fluoride [18F-NaF]) could predict restenosis following PTA.BackgroundRestenosis following lower limb percutaneous transluminal angioplasty (PTA) is common, unpredictable, and challenging to treat. Currently, it is impossible to predict which patient will suffer from restenosis following angioplasty.MethodsIn this prospective observational cohort study, 50 patients with symptomatic peripheral arterial disease underwent 18F-FDG and 18F-NaF PET/computed tomography (CT) imaging of the superficial femoral artery before and 6 weeks after angioplasty. The primary outcome was arterial restenosis at 12 months.ResultsForty subjects completed the study protocol with 14 patients (35%) reaching the primary outcome of restenosis. The baseline activities of femoral arterial inflammation (18F-FDG tissue-to-background ratio [TBR] 2.43 [interquartile range (IQR): 2.29 to 2.61] vs. 1.63 [IQR: 1.52 to 1.78]; p < 0.001) and microcalcification (18F-NaF TBR 2.61 [IQR: 2.50 to 2.77] vs. 1.69 [IQR: 1.54 to 1.77]; p < 0.001) were higher in patients who developed restenosis. The predictive value of both 18F-FDG (cut-off TBRmax value of 1.98) and 18F-NaF (cut-off TBRmax value of 2.11) uptake demonstrated excellent discrimination in predicting 1-year restenosis (Kaplan Meier estimator, log-rank p < 0.001).ConclusionsBaseline and persistent femoral arterial inflammation and micro-calcification are associated with restenosis following lower limb PTA. For the first time, we describe a method of identifying complex metabolically active plaques and patients at risk of restenosis that has the potential to select patients for intervention and to serve as a biomarker to test novel interventions to prevent restenosis. 相似文献