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Impact of random and scattered coincidences from outside of field of view on positron emission tomography/computed tomography imaging with different reconstruction protocols
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作者 Mahak Osouli Alamdari Pardis Ghafarian +2 位作者 Arman Rahmim Mehrdad Bakhshayesh‑Karam Mohammad Reza Ay 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第12期40-52,共13页
Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outsi... Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outside the field of view(FOV)on PET image quality for different reconstruction protocols.Imaging was performed on the Discovery 690 PET/CT scanner,using experimental configurations including the NEMA phantom(a body phantom,with six spheres of different sizes)with a signal background ratio of 4:1.The NEMA phantom(phantom I)was scanned separately in a one-bed position.To simulate the effect of random and scatter coincidences from outside the FOV,six cylindrical phantoms with various diameters were added to the NEMA phantom(phantom II).The 18 emission datasets with mean intervals of 15 min were acquired(3 min/scan).The emission data were reconstructed using different techniques.The image quality parameters were evaluated by both phantoms.Variations in the signal-to-noise ratio(SNR)in a 28-mm(10-mm)sphere of phantom II were 37.9%(86.5%)for ordered-subset expectation maximization(OSEM-only),36.8%(81.5%)for point spread function(PSF),32.7%(80.7%)for time of flight(TOF),and 31.5%(77.8%)for OSEM+PSF+TOF,respectively,indicating that OSEM+PSF+TOF reconstruction had the lowest noise levels and lowest coefficient of variation(COV)values.Random and scatter coincidences from outside the FOV induced lower SNR,lower contrast,and higher COV values,indicating image deterioration and significantly impacting smaller sphere sizes.Amongst reconstruction protocols,OSEM+PSF+TOF and OSEM+PSF showed higher contrast values for sphere sizes of 22,28,and 37 mm and higher contrast recovery coefficient values for smaller sphere sizes of 10 and 13 mm. 展开更多
关键词 Positron emission tomography/computed tomography(PET/ct) Random coincidences Scatter coincidences·Time of flight(TOF) Point spread function(PSF) Field of view(FOV) Noise equivalent count rate(NECR) Signal-toNoise ratio(SNR)
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Evaluation of response to gemcitabine plus cisplatin-based chemotherapy using positron emission computed tomography for metastatic bladder cancer
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作者 HakanÖztürk İnançKarapolat 《World Journal of Clinical Cases》 SCIE 2023年第36期8447-8457,共11页
BACKGROUND The purpose of the present study was to examine retrospectively the contribution of 18Fluorodeoxyglucose positron emission tomography computed tomography(18FDG-PET/CT)to the evaluation of response to first-... BACKGROUND The purpose of the present study was to examine retrospectively the contribution of 18Fluorodeoxyglucose positron emission tomography computed tomography(18FDG-PET/CT)to the evaluation of response to first-line gemcitabine plus cispla-tin-based chemotherapy in patients with metastatic bladder cancer.AIM To evaluate the response to Gemcitabine plus Cisplatin-based chemotherapy using 18FDG-PET/CT imaging in patients with metastatic bladder cancer.METHODS Between July 2007 and April 2019,79 patients underwent 18FDG-PET/CT imaging with the diagnosis of Metastatic Bladder Carcinoma(M-BCa).A total of 42 pa-tients(38 male,4 female)were included in the study,and all had been admi-nistered Gemcitabine plus Cisplatin-based chemotherapy.After completion of the therapy,the patients underwent a repeat 18FDG-PET/CT scan and the results were compared with the PET/CT findings before chemotherapy according to European Organisation for the Research and treatment of cancer criteria.Mean age was 66.1 years and standard deviation was 10.7 years(range:41–84 years).RESULTS Of the patients,seven(16.6%)were in complete remission,17(40.5%)were in partial remission,six(14.3%)had a stable disease,and 12(28.6%)had a pro-gressive disease.The overall response rate was 57.1 percent.CONCLUSION 18FDG-PET/CT can be considered as a successful imaging tool in evaluating response to first-line chemotherapy for metastatic bladder cancer.Anatomical and functional data obtained from PET/CT scans may be useful in the planning of secondline and thirdline chemotherapy. 展开更多
关键词 Metastatic bladder cancer Response to chemotheraphy Positron emission tomography computed tomography 18FDG-PET/ct
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Radiation Dose Survey of Pediatric Chest Computed Tomography Examinations: A Local Diagnostic Reference Levels Approach to Patient Safety
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作者 Turki Alruwaili Bani Alsubaie +1 位作者 Salman Altimyat Khaled Soliman 《Journal of Applied Mathematics and Physics》 2023年第7期2137-2143,共7页
Objectives: The aim of this work was to initially establish both age and weight driven pediatric diagnostic reference levels (DRLs) for chest computed tomography (CT) examinations performed at tertiary care medical in... Objectives: The aim of this work was to initially establish both age and weight driven pediatric diagnostic reference levels (DRLs) for chest computed tomography (CT) examinations performed at tertiary care medical institution. Another aim was to compare the presented data with internationally published ones. This initial data shall serve as basis for establishing a national DRLs values for pediatric diagnostic CT examinations. Methods: Dosimetric indexes were collected for the chest examination for 93 patients during the past 2 years in a tertiary care medical city. Results: The results are within and below the international reported levels for chest CT in several countries. Conclusion: Continuous monitoring of the radiation doses received by the patients in computed tomography is continuous and ongoing process in order to ensure compliance and to optimize clinical imaging protocols. More extensive data acquisition and analysis are required to allow better understanding of the contributing factors leading to less patient radiation dose while preserving the clinical image quality. . 展开更多
关键词 computed tomography Chest ct Diagnostic Reference Levels Monitoring Optimization
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Experiences and benefits of positron emitted tomography-computed tomography (PET-CT) combined with video-assisted thoracoscopic surgery (VATS) in the diagnosis of Stage 1 sarcoidosis 被引量:3
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作者 LUH Shi-ping WU Tzu-chin +2 位作者 WANG Yao-tung TSAO Thomas Chang-yao CHEN Jia-yuh 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2007年第6期410-415,共6页
Background: The purpose of this study was to describe our experiences and analyze the benefits of video-assisted thoracoscopic surgery (VATS) combined with positron emitted tomography (PET)-computed tomography (CT) in... Background: The purpose of this study was to describe our experiences and analyze the benefits of video-assisted thoracoscopic surgery (VATS) combined with positron emitted tomography (PET)-computed tomography (CT) in the diagnosis of patients with early (Stage 1) sarcoidosis. Methods: From 1995 to 2006, seven patients (two males, five females), with ages ranging from 26 to 58 years, were impressed with Stage 1 sarcoidosis (mediastinal or hilar lymph nodes involvements without lung in- volvement) by histological examination of intrathoracic lymph nodes (LNs) and/or lung parenchyma taken from VATS biopsy. Three of them received PET or PET-CT evaluation. VATS was approached from the right and left side in one and six patients, respectively, according to the locations of their lesions. Results: All the VATS biopsied LNs or lung specimens were adequate for establishing diagnosis. Mediastinal LNs were taken from Groups 3, 4 in four, Group 7 in two, and Groups 5, 6 in one of them. Hilar LNs biopsies were performed in four cases. Lung biopsy was performed in all but two cases. All of them were expressed pathologically or radiologically as Stage 1 sarcoidosis. PET-CT revealed high emission signals over these affected LNs. These patients received oral steroid treatment or follow up only. All of them were followed up from 5 months to 11 years with satis- factory results. Conclusion: VATS biopsy is a minimally invasive, safe and effective procedure. It can be used as a diagnostic alternative of transbronchial lung biopsy (TBLB), and can harvest larger and more areas of specimens than mediastinoscopy for staging patients with sarcoidosis. PET-CT can provide us more accurate information about the characteristics and localization of these lesions before biopsy. VATS combined with PET-CT can provide more accurate and earlier diagnosis of patients with unknown intrathoracic lesions, including the sarcoidosis. 展开更多
关键词 1期类肉状瘤病 PET-ct 视频辅助胸腔镜手术 联合诊断 肺脏 淋巴结
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Characterization of microstructure evolution of cement paste by micro computed tomography 被引量:3
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作者 何永佳 Jason Mote David A. Lange 《Journal of Central South University》 SCIE EI CAS 2013年第4期1115-1121,共7页
Micro computed tomography (Micro-CT) was applied to obtain three-dimensional images of the microstructure of cement paste (water-to-cement mass ratio of 0.5) at different ages. By using the Amira software, component p... Micro computed tomography (Micro-CT) was applied to obtain three-dimensional images of the microstructure of cement paste (water-to-cement mass ratio of 0.5) at different ages. By using the Amira software, component phases of the cement paste such as pores, hydration products, and unhydrated clinker particles were segmented from each other based on their 3D image grey levels; their relative contents were also calculated with the software, and the data are 61.2%, 0% and 38.8% at the beginning of hydration and 11.8%, 78.5% and 9.7% at 28 d age, respectively. The hydration degree of cement paste at different ages was compared with the experimental data acquired by loss on ignition (LOI) tests. The results show that the calculated and measured data reasonably agree with each other, which indicates that micro-CT is a useful and reliable approach to characterize the micro structure evolution of hydrating cement paste. 展开更多
关键词 计算机断层扫描 水泥净浆 组织演变 表征 粘贴 微型 水化产物 三维图像
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Relation between Epicardial Adipose Tissue Thickness Assessed by Multidetector Computed Tomography and Significance of Coronary Artery Disease 被引量:1
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作者 Neveen I. Samy Mohammad Fakhry Walaa Farid 《World Journal of Cardiovascular Diseases》 2020年第2期91-101,共11页
Objective: To evaluate the relation between epicardial adipose tissue (EAT) thickness and also pericoronary fat assessed by Multidetector Computed Tomography (MDCT) with both calcium score and significance of coronary... Objective: To evaluate the relation between epicardial adipose tissue (EAT) thickness and also pericoronary fat assessed by Multidetector Computed Tomography (MDCT) with both calcium score and significance of coronary artery disease. Background: Epicardial adipose tissue (the visceral fat of the heart present under the visceral layer of the pericardium) has the same origin of abdominal visceral fat, which is known to be strongly related to the development of coronary artery atherosclerosis. Multidetector CT (MDCT) provides an accurate and reproducible quantification of EAT due to its high spatial and temporal resolution. Patients and Methods: The current study included 70 patients with low-intermediate probability of coronary artery disease. All patients were subjected to 256 Multidetectors CT to assess EAT thickness, the mean thickness of the pericoronary fat surrounding the three coronary arteries and coronary calcium score. Also coronary CT angiography was done and patients were then divided into 3 groups according to significance of coronary atherosclerosis: Group 1: No atherosclerosis (20 patients), Group 2: Non obstructive atherosclerosis (luminal narrowing less than 50% in diameter) (25 patients), Group3: Obstructive atherosclerosis (luminal narrowing ≥ 50%) (25 patients). Results: The mean EAT thickness and the mean pericoronary fat thickness were significantly higher in patients with obstructive coronary artery disease (CAD) with stenosis > 50% (group 3) compared to other groups with normal coronaries or non obstructive (CAD). ROC curve was used to define the best cut off value of the thickness of both EAT and pericoronary fat in predicting the obstructive CAD group which was ≥7.2 and 12.6 mm for epicardial and pericoronary fat respectively. Also there is a positive correlation between both epicardial adipose tissue and pericoronary fat thickness and the coronary calcium score. Conclusion: EAT thickness and pericoronary fat thickness can be used in predicting the significance of coronary artery disease. 展开更多
关键词 CORONARY Artery Disease Multi Detector computed tomography CORONARY ct ANGIOGRAPHY EPICARDIAL ADIPOSE Tissue Thickness Pericoronary Fat Thickness
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Acute coronary syndrome on non-electrocardiogram-gated contrastenhanced computed tomography 被引量:1
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作者 Shu Yoshihara 《World Journal of Radiology》 2022年第2期30-46,共17页
It is not rare for acute coronary syndrome(ACS)patients to present with symptoms that are atypical,rather than chest pain.It is sometimes difficult to achieve a definitive diagnosis of ACS for such patients who presen... It is not rare for acute coronary syndrome(ACS)patients to present with symptoms that are atypical,rather than chest pain.It is sometimes difficult to achieve a definitive diagnosis of ACS for such patients who present with atypical symptoms,normal initial biomarkers of myocardial necrosis,and normal or nondiagnostic electrocardiograms(ECGs).Although cardiac CT allows for assessments of coronary artery stenosis as well as myocardial perfusion defect in patients with suspected ACS,it requires ECG gating and is usually performed with high-performance multislice CT for highly probable ACS patients.However,several recent reports have stated that ACS is detectable by myocardial perfusion defects even on routine non-ECG-gated contrast-enhanced CT.A growing number of contrast-enhanced CT scans are now being performed in emergency departments in search of pathologies responsible for a patient’s presenting symptoms.In order to avoid inappropriate management for this life-threatening event,clinicians should be aware that myocardial perfusion defect is more commonly detectable even on routine non-ECG-gated contrast-enhanced CT performed in search of other pathologies. 展开更多
关键词 Acute coronary syndrome Non-ECG-gated ct computed tomography Myocardial perfusion defect Emergency department
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Comparison of computed tomography and magnetic resonance imaging for the detection of mandibular condylar osteochondroma 被引量:1
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作者 Molun Shen Ling Zhu +2 位作者 Hongbo Yu Lei Zhang Xudong Wang 《Oncology and Translational Medicine》 2018年第3期108-115,共8页
Objective The purpose of this study was to compare computed tomography(CT) and magnetic resonance imaging(MRI) for the detection of mandibular condylar osteochondroma.Methods Preoperative CT and MRI of 33 patients wit... Objective The purpose of this study was to compare computed tomography(CT) and magnetic resonance imaging(MRI) for the detection of mandibular condylar osteochondroma.Methods Preoperative CT and MRI of 33 patients with unilateral condylar osteochondroma were reviewed. The morphology, location, continuity with the parent bone, cartilage cap, perichondrium of tumors, and changes in soft and hard tissues adjacent to the lesions were investigated by two reviewers. Data were analyzed using Mc Nemar test. A P value < 0.05 was considered significant.Results Among the 33 condylar osteochondromas, 11 were of the diffuse type, 10 were of the sessile type, and 12 were of the pedunculated type. Continuity with the cortex and marrow of the host condyle was observed on both CT and MRI. Both modalities had identical detection rates of surface reconstruction of the temporal bone joint, condylar dislocation, and pseudarthrosis formation. However, MRI showed significantly higher detection rates of the cartilage cap and perichondrium than CT(P < 0.05). Furthermore, MRI showed ipsilateral and contralateral temporo-mandibular joint(TMJ) disc displacement in 4 cases and 6 cases, respectively, and ipsilateral and contralateral TMJ effusion in 20 cases and 14 cases, respectively.Conclusion CT can intuitively display the morphology and spatial location of condylar osteochondromas through three-dimensional reconstruction. MRI may be superior to CT in the detection of cartilage cap, perichondrium of the condylar osteochondroma, and changes in the TMJ and adjacent soft tissues. 展开更多
关键词 断层摄影术 声成像 磁性 计算 MRI 外科手术 表面重建 形态学
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Qualitative visual trichotomous assessment improves the value of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in predicting the prognosis of diffuse large B-cell lymphoma 被引量:1
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作者 Xu Zhang Wei Fan +6 位作者 Ying-Ying Hu Zhi-Ming Li Zhong-Jun Xia Xiao-Ping Lin Ya-Rui Zhang Pei-Yan Liang Yuan-Hua Li 《Chinese Journal of Cancer》 SCIE CAS CSCD 2015年第6期21-28,共8页
Introduction:Fluorine-18 fluorodeoxyglucose(18F-FDG)positron emission tomography/computed tomography(PET/CT)is a powerful tool for monitoring the response of diffuse large B-cell lymphoma(DLBCL)to therapy,but the crit... Introduction:Fluorine-18 fluorodeoxyglucose(18F-FDG)positron emission tomography/computed tomography(PET/CT)is a powerful tool for monitoring the response of diffuse large B-cell lymphoma(DLBCL)to therapy,but the criteria to interpret PET/CT results remain under debate.We investigated the value of post-treatment PET/CT in predicting the prognosis of DLBCL patients when interpreted according to qualitative visual trichotomous assessment(QVTA)criteria compared with the Deauvil e criteria.Methods:In this retrospective study,final PET/CT scans of DLBCL patients treated with rituximab-based regimens between October 2005 and November 2010 were interpreted using the Deauvil e and QVTA criteria.Survival curves were estimated using Kaplan-Meier analysis and compared using the log-rank test.Results:A total of 253 patients were enrol ed.The interpretation according to the Deauvil e criteria revealed that 181patients had negative PET/CT scan results and 72 had positive results.The 3 year overal survival(OS)rate was significantly higher in patients with negative scan results than in those with positive results(91.6%vs.57.5%,P<0.001).The72 patients with positive scan results according to the Deauville criteria were divided into two groups by the interpretation according to the QVTA criteria:29 had indeterminate results,and 43 had positive results.The 3 year OS rate was significantly higher in patients with indeterminate scan results than in those with positive results(91.2%vs.33.5%,P<0.001)but was similar between patients with negative and indeterminate scan results(91.6%vs.91.2%,P=0.921).Conclusions:Compared with the Deauvil e criteria,using the QVTA criteria for interpreting post-treatment PET/CT scans of DLBCL patients is likely to reduce the number of false positive results.The QVTA criteria are feasible for therapeutic outcome evaluation and can be used to guide risk-adapted therapy. 展开更多
关键词 正电子发射断层扫描 计算机断层扫描 B细胞淋巴瘤 脱氧葡萄糖 定性视觉 预后 预测 评估
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Hybrid reconstruction algorithm for computed tomography based on diagonal total variation
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作者 Lu-Zhen Deng Peng He +3 位作者 Shang-Hai Jiang Mian-Yi Chen Biao Wei Peng Feng 《Nuclear Science and Techniques》 SCIE CAS CSCD 2018年第3期172-180,共9页
Inspired by total variation(TV), this paper represents a new iterative algorithm based on diagonal total variation(DTV) to address the computed tomography image reconstruction problem. To improve the quality of a reco... Inspired by total variation(TV), this paper represents a new iterative algorithm based on diagonal total variation(DTV) to address the computed tomography image reconstruction problem. To improve the quality of a reconstructed image, we used DTV to sparsely represent images when iterative convergence of the reconstructed algorithm with TV-constraint had no effect during the reconstruction process. To investigate our proposed algorithm, the numerical and experimental studies were performed, and rootmean-square error(RMSE) and structure similarity(SSIM)were used to evaluate the reconstructed image quality. The results demonstrated that the proposed method could effectively reduce noise, suppress artifacts, and reconstruct highquality image from incomplete projection data. 展开更多
关键词 computed tomography (ct) Sparse-view reconstruction DIAGONAL total variation (DTV) COMPRESSIVE sensing (CS)
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Assessment of Organ Dose by Direct and Indirect Measurements for a Wide Bore X-Ray Computed Tomography Unit That Used in Radiotherapy
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作者 Emine Dilek Cakmak Nina Tuncel Bora Sindir 《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 2015年第2期132-142,共11页
The aim of this study was to investigate the organ doses of patients undergoing computed tomography (CT) examination using the wide bore General Electric (GE) “Light Speed RT” unit. The head, chest and pelvic region... The aim of this study was to investigate the organ doses of patients undergoing computed tomography (CT) examination using the wide bore General Electric (GE) “Light Speed RT” unit. The head, chest and pelvic regions of the Rando-phantom were scanned with 120 kV, 200 mA, and 2.5 mm slice thickness for helical and axial modes. Thermoluminescent Dosimeter (TLD) pairs were used for the dosimetry of 10 organs. TL-counts were converted to dose by using CTDIcenter dose on CT-phantom. For the calculation of the organ doses, the ImPACT software was utilized by entering CTDIair (100 mAs) in small and large field of view (26.43 and 21.17 mGy respectively). The in-field dose ranges in helical and axial modes were 64.3 - 38 mGy and 47.6 - 19.7 mGy in head, 48.3 - 14.1 mGy and 34.1 - 10 mGy in chest, 28.4 - 10.2 mGy and 21 - 8.5 mGy in pelvic, respectively. The organ doses from software and TLD were compared and tailored as the in-field and the out-field radiation. First results showed that the organ dose was relatively higher in the helical mode on both direct and indirect measurement. The in-field organ dose differences between TLD and software were seen. In helical and axial modes, the dose differences ranged from +1 to +13.3 and -8.3 to +9.6 mGy for head exam, +1.1 to +15.3 and +0.3 to +9.1 mGy for chest, and -21.7 to +1.9 and -15.5 to +1.8 mGy for pelvic. The availability of this program for organ dose calculations by measuring CTDIair value for CT device used in the radiotherapy would be considered valuable. 展开更多
关键词 WIDE BORE computed tomography (ct) Thermoluminescent DOSIMETER (TLD) ORGAN Dose
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Conception the Fluid Flow Behavior within Oil Reservoir Rock by Using Computed Tomography(CT)Scan
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作者 Amani J.Majeed Falah A Abood Ahmed K.Alshara 《Journal of Mechanical Engineering Research》 2021年第2期11-20,共10页
The behavior of fluid flow has been studied during the different flow media over the past decades.In addition,the behavior of the flow of fluid through porous media has garnered much research interest.This paper sheds... The behavior of fluid flow has been studied during the different flow media over the past decades.In addition,the behavior of the flow of fluid through porous media has garnered much research interest.This paper sheds light on fissured rocks of oil reservoir media(as one of the porous media domain),and the effect of these fissured on fluid flow.In this article,the Finite Volume Method(FVM)has been used to visualize the behavior of single-phase fluid flow in an actual core according to the dual-porosity dual permeability model.The study was conducted in two parts,the first was the image processing for one of the real oil reservoir fractured rock images,where the image was processed and simulated by ANSYS-CFX software,and the results showed a complete visualizing of the fluid behavior during this domain.As for the other side,a simulation of a real reservoir rock belonging to the Al-Nour field in Iraq/Misan was made.The X-ray Computed Tomography(CT)scan has been used to convert the real fractured core to a dynamic domain.ANSYS-CFX program has been used and the results illustrated the pressure counter,the velocity counter,the velocity streamline,and the velocity vectors for the studied model in three dimensions.A comparison was made between the productivity index for fractured and non-fractured rock and the results explained that the presence of fracture can improve the productivity index to about 5.74%. 展开更多
关键词 computed tomography(ct)scan Al-Nour field Fluid flow
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优化双下肢动脉能谱CT血管造影成像方案
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作者 胡莹莹 张珂 +3 位作者 何辰宇 孙宏亮 王蕾 谢晟 《中国介入影像与治疗学》 北大核心 2024年第4期242-246,共5页
目的优化双下肢动脉能谱CT血管造影(CTA)成像方案。方法回顾性分析30例疑诊双下肢动脉硬化性闭塞症(ASO)患者双下肢动脉能谱CTA资料,经重建获得40~80 keV(间隔5 keV)单能量(共9种)及100 kVp混合能量图像,对比双下肢动脉在不同图像中的C... 目的优化双下肢动脉能谱CT血管造影(CTA)成像方案。方法回顾性分析30例疑诊双下肢动脉硬化性闭塞症(ASO)患者双下肢动脉能谱CTA资料,经重建获得40~80 keV(间隔5 keV)单能量(共9种)及100 kVp混合能量图像,对比双下肢动脉在不同图像中的CT值、噪声(SD)值、信噪比(SNR)及对比度噪声比(CNR);针对50、60 keV单能量和100 kVp混合能量图像质量及血管节段的可诊断性进行主观评估,观察40、45、50、60 keV单能量和100 kVp混合能量图像的自动去骨能力。结果40~80 keV范围内,随keV升高,各动脉在图像中的CT值、SD值、SNR及CNR均逐渐降低。相比100 kVp,腘动脉(PA)及其近端动脉的CT值、CNR及SNR均在40~55 keV图像中升高(P均<0.05);50~55 keV图像中SD值升高(P均<0.05),而60 keV图像中差异无统计学意义(P>0.05)。50及60 keV图像质量主观评分及可诊断动脉节段数与100 kVp差异均无统计学意义(P均>0.05)。PA以远节段的SNR及CNR在各单能量图像及100 kVp图像中差异均无统计学意义,其CT值在40~45 keV图像中、SD在40 keV图像中均高于100 kVp(P均<0.05),但SD在45 keV与100 kVp图像中差异无统计学意义(P>0.05);50 keV图像中,PA以远节段图像质量主观评分及可诊断节段数均高于60 keV及100 kVp(P均<0.05)。40 keV图像对9例(9/30,30.00%)、45 keV图像对6例(6/30,20.00%)不能自动去骨,50及60 keV、100 kVp对30例(30/30,100%)均可自动去骨。结论行双下肢动脉能谱CTA时,对PA及其近端节段以60 keV单能量成像较佳,对其以远或双下肢全程则以50 keV单能量成像较佳。 展开更多
关键词 下肢 动脉 ct血管成像 能谱ct
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基于增强CT影像组学预测食管鳞癌淋巴血管侵犯状态的价值
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作者 李扬 王向明 +8 位作者 谷霄龙 杨丽 王琦 时高峰 随义 徐校胜 岳萌 王明博 任嘉梁 《放射学实践》 CSCD 北大核心 2024年第2期239-246,共8页
目的:探讨基于增强CT影像组学预测食管鳞癌(ESCC)淋巴血管侵犯(LVI)的价值。方法:回顾性搜集行根治性切除术并经术后病理证实的224例食管鳞癌患者,其中包括66例LVI阳性和158例LVI阴性患者。所有患者均在术前2周内进行胸部增强CT扫描。... 目的:探讨基于增强CT影像组学预测食管鳞癌(ESCC)淋巴血管侵犯(LVI)的价值。方法:回顾性搜集行根治性切除术并经术后病理证实的224例食管鳞癌患者,其中包括66例LVI阳性和158例LVI阴性患者。所有患者均在术前2周内进行胸部增强CT扫描。将入组的患者按照7:3的比例随机分为训练集和测试集。使用3D Slicer软件逐层勾画全肿瘤感兴趣区(ROI),采用Python软件的Pyradiomics包提取肿瘤组织的影像组学特征,建立影像组学模型用于预测食管鳞癌的LVI状态并进行验证。采用受试者工作特征(ROC)曲线的曲线下面积(AUC)、敏感度、特异度、准确度、阳性预测值和阴性预测值来评价影像组学模型的诊断效能,使用校准曲线评价影像组学模型在训练集和测试集中的拟合程度。使用决策曲线分析(DCA)评价影像组学模型的临床应用价值。结果:从全肿瘤ROI中提取了1130个组学特征,经过筛选最终保留了7个影像组学特征,并使用多因素logistic回归建立影像组学预测模型。在训练集中,影像组学模型预测LVI的AUC值为0.930,敏感度为0.851,特异度为0.919,准确度为0.899,阳性预测值为0.816,阴性预测值为0.936;在测试集中,AUC值为0.897,敏感度为0.789,特异度为0.787,准确度为0.788,阳性预测值为0.600,阴性预测值为0.902。校准曲线显示影像组学模型在训练集及测试集中的预测概率与实际概率的一致性良好。DCA曲线显示影像组学模型具有良好的临床应用价值。结论:基于增强CT构建的影像组学模型,能够在术前有效预测食管鳞癌的LVI状态。 展开更多
关键词 食管鳞癌 影像组学 淋巴血管侵犯 体层摄影术 X线计算机 增强ct
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定量CT评价胸椎骨密度及与年龄相关的骨丢失
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作者 赵君禄 刘斋 +2 位作者 赵德园 聂关伟 任庆云 《实用医学杂志》 CAS 北大核心 2024年第10期1429-1433,共5页
目的探讨胸椎定量CT(QCT)测量骨密度及骨丢失率的可行性。方法选取因健康体检及急腹症行全腹部CT扫描的患者708例,使用QCT软件测量T10-L3椎体骨密度。将受检者按每10岁为一个年龄段分组。计算每个年龄组的胸椎及腰椎骨密度,并计算各组... 目的探讨胸椎定量CT(QCT)测量骨密度及骨丢失率的可行性。方法选取因健康体检及急腹症行全腹部CT扫描的患者708例,使用QCT软件测量T10-L3椎体骨密度。将受检者按每10岁为一个年龄段分组。计算每个年龄组的胸椎及腰椎骨密度,并计算各组别的峰值骨密度及骨丢失率。胸椎与腰椎骨密度及其与年龄的相关性采用Pearson相关分析。结果男性、女性骨密度峰值均在20~29岁年龄组,30岁以后胸腰椎骨密度开始不同程度减低,80~89岁女性胸椎及腰椎累计骨丢失率分别为60.61%及61.34%,而男性分别为44.45%及49.35%。男性与女性胸腰椎骨密度均与年龄呈负相关(P<0.01)。胸椎与腰椎骨密度呈正相关(男性r=0.96、女性r=0.98,P<0.01)。结论胸椎及腰椎QCT均能准确地显示不同年龄组的骨密度及骨丢失情况,胸椎QCT可以作为评价和监测骨丢失的一种方法。 展开更多
关键词 骨丢失 骨密度 体层摄影术 X线计算机 定量ct 胸椎
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基于不同管电压的人工智能重建算法对胸部体模CT扫描图像质量和辐射剂量的影响研究
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作者 惠庆桃 刘婷 +3 位作者 卿翔 李洁 王冠 马春 《中国医学装备》 2024年第3期19-23,共5页
目的:基于成年男性仿真胸部体模(PH-N1)CT扫描,探究不同管电压结合人工智能(AI)重建(CI)算法对胸部体模CT扫描图像质量和辐射剂量的影响。方法:采用512层超高端CT分为4种管电压对体模进行扫描,分别为70 kV、80 kV、100 kV和120 kV,对不... 目的:基于成年男性仿真胸部体模(PH-N1)CT扫描,探究不同管电压结合人工智能(AI)重建(CI)算法对胸部体模CT扫描图像质量和辐射剂量的影响。方法:采用512层超高端CT分为4种管电压对体模进行扫描,分别为70 kV、80 kV、100 kV和120 kV,对不同管电压的CT扫描图像采用10%、30%、50%、70%和90%CI算法重建1 mm薄层图像,比较4组扫描的容积剂量指数(CTDIvol)和剂量-长度乘积(DLP)。测量图像主动脉、腹壁脂肪及竖棘肌的CT值、标准偏差(SD)值,由两名5年以上工作经验的高年资诊断医师独立双盲的对图像质量进行5分制评估,并行Kappa一致性检验。采用单因素方差分析比较图像目标组织的CT值、SD值差异。采用Friedman秩和检验比较组间主观图像质量的差异。结果:4种不同管电压的CTDIvol和DLP比较,差异有统计学意义(F=1855.617、3996.118,P<0.05)。在70 kV管电压下,10%、30%、50%、70%和90%CI算法重建的主动脉、腹壁脂肪及竖棘肌的CT值比较,差异均无统计学意义(P>0.05),而SD值差异均有统计学意义(F=32.267、53.327、14.873,P<0.05)。在90%权重的CI算法重建4种不同管电压下,主动脉、腹壁脂肪及竖棘肌的CT值随着管电压的降低,CT值逐渐降低,差异有统计学意义(F=139.899、2563.93、219.231,P<0.05)。两名诊断医师对各组图像的主观评分一致性较好(Kappa=0.712~0.869)。结论:CI算法在70 kV管电压下90%权重的CI算法重建图像与80 kV、90 kV、120 kV图像相比,可以明显降低辐射剂量,同时图像具有良好信噪比。 展开更多
关键词 计算机体层摄影 人工智能 重建算法 图像质量 辐射剂量
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宽体探测器CT血管造影与超声心动图对小儿先天性心脏病的诊断效能
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作者 祁冬 李娟 +3 位作者 孙景巍 董楠 贾媛 沈艳 《联勤军事医学》 CAS 2024年第1期22-25,35,共5页
目的探讨宽体探测器CT血管造影(computer tomography angiography,CTA)与超声心动图(ultrasound cardiogram,UCG)在小儿先天性心脏病(congenital heart disease,CHD)的诊断效能。方法回顾性分析2019-08/2023-09月作者医院收治的65例疑似... 目的探讨宽体探测器CT血管造影(computer tomography angiography,CTA)与超声心动图(ultrasound cardiogram,UCG)在小儿先天性心脏病(congenital heart disease,CHD)的诊断效能。方法回顾性分析2019-08/2023-09月作者医院收治的65例疑似CHD患儿的影像学资料,所有患儿均行心脏CTA及UCG检查。对两种检查方式的图像质量进行主观评价并比较其差异;以手术或数字减影血管造影(digital subtraction angiography,DSA)为“金标准”,对比两种检查方式在诊断CHD的灵敏度、特异度、阳性预测值、阴性预测值及准确率的差异,并应用Kappa检验比较与“金标准”结果的一致性;采用受试者工作特征(receiver operating characteristic,ROC)曲线分析两种检查方式对小儿CHD的诊断效能。结果CTA诊断小儿CHD心外畸形图像质量主观评分明显高于UCG,二者比较差异具有统计学意义(P<0.05),心内畸形图像质量主观评分二者比较差异无统计学意义(P>0.05)。两名医师对图像质量主观评分的一致性较好(κ=0.802)。CTA、UCG诊断小儿CHD心内畸形准确率比较差异无统计学意义(P>0.05);CTA诊断小儿CHD心外畸形准确率为96.43%,显著高于UCG 50.00%,组间比较差异具有统计学意义(P<0.05)。CTA诊断小儿CHD的灵敏度、特异度、阳性预测值、阴性预测值及准确率分别为90.00%、60.00%、96.43%、33.33%及87.69%,与手术或DSA结果一致性较好(κ=0.766);UCG诊断CHD的灵敏度、特异度、阳性预测值、阴性预测值及准确率分别为83.33%、20.00%、92.59%、9.09%及79.81%,与手术或DSA结果一致性一般(κ=0.522)。CTA、UCG两种检查方式诊断小儿CHD的灵敏度、特异度、阴性预测值及准确率差异比较均有统计学意义(P均<0.05)。ROC曲线分析结果显示,CTA与UCG诊断小儿CHD的曲线下面积(area under the cure,AUC)分别为0.853和0.773,二者比较差异有统计学意义(P<0.05)。结论宽体探测器CTA在小儿CHD心外畸形方面的诊断效能优于UCG,而在心内畸形方面稍差,因此建议二者联合检查,诊断价值更高。 展开更多
关键词 先天性心脏病 超声心动图 宽体探测器ct ct血管造影
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螺旋CT三维扫描重建联合3D打印用于髋臼骨折手术的价值研究
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作者 王姗姗 牛俊巧 +3 位作者 王佳 李小娟 洪悦 王利 《中国医学装备》 2024年第5期59-63,共5页
目的:探讨螺旋CT三维扫描重建联合3D打印技术在髋臼骨折外科手术中的应用价值。方法:选取2018年1月至2020年12月新疆维吾尔自治区人民医院收治的71例髋臼骨折并接受手术治疗的患者,依据治疗方式的不同将其分为观察组(38例)和对照组(33... 目的:探讨螺旋CT三维扫描重建联合3D打印技术在髋臼骨折外科手术中的应用价值。方法:选取2018年1月至2020年12月新疆维吾尔自治区人民医院收治的71例髋臼骨折并接受手术治疗的患者,依据治疗方式的不同将其分为观察组(38例)和对照组(33例),观察组采用螺旋CT三维重建,并以3D打印辅助内固定治疗,对照组采用常规手术治疗。比较两组患者手术效果及恢复情况。结果:观察组骨折复位质量评分及分项百分制髋功能评分高于对照组,术中出血量、术中透视次数、手术用时及住院时间均明显低于对照组,差异均有统计学意义(t=23.426、4.216、3.425、17.783,P<0.05);观察组和对照组骨折复位优良率分别为94.74%和78.79%,差异有统计学意义(x^(2)=4.059,P<0.05);观察组患者髋关节功能评分中疼痛、功能及关节活动均高于对照组,差异有统计学意义(t=-4.873、-5.776、-6.247,P<0.05);观察组并发症发生率明显低于对照组,差异有统计学意义(x^(2)=4.059,P<0.05)。结论:在髋臼骨折围术期应用螺旋CT三维重建结合3D打印可进一步保证手术的安全性和可行性,提高手术质量和效率,促进术后恢复。 展开更多
关键词 螺旋ct 三维重建 3D打印 髋臼骨折
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胸部定量CT对COPD患者治疗反应预测因素分析
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作者 刘佳萍 张卫国 《河北医药》 CAS 2024年第3期376-379,共4页
目的分析胸部定量CT扫描对慢性阻塞性疾病(COPD)患者治疗反应的预测因素。方法回顾性分析2018年8月至2021年2月接受治疗COPD患者120例的临床资料,对其随访1年,根据肺功能检测结果将其分为有治疗反应组[n=24,第1秒用力呼气容积(FEV_(1))... 目的分析胸部定量CT扫描对慢性阻塞性疾病(COPD)患者治疗反应的预测因素。方法回顾性分析2018年8月至2021年2月接受治疗COPD患者120例的临床资料,对其随访1年,根据肺功能检测结果将其分为有治疗反应组[n=24,第1秒用力呼气容积(FEV_(1))增加≥0.225 L]和非无治疗反应组(n=96,FEV_(1)增加<0.225 L)。对2组一般资料进行单因素分析,对其中差异有统计学意义的变量进行多因素Logistic回归分析,从而筛选出预测COPD患者治疗反应的因素。结果单因素分析结果显示,有治疗反应组和无治疗反应组在EI、ATI、Pi10、WA%、T方面的差异有统计学意义(P<0.05),而2组间性别比、年龄、体重指数、GOLD分期、入院肺功能检测的差异无统计学意义(P>0.05)。多因素Logistic回归分析结果显示,Pi10为预测COPD患者治疗反应的因素(OR=2.321,P<0.05)。ROC曲线显示,Pi10在预测COPD患者治疗反应中具有极高的临床价值,ROC曲线显示,Pi10预测COPD患者治疗反应的曲线下面积为0.701,95%CI为0.610~0.781,约登指数为0.354,最佳截断值为4.65 mm,灵敏度为85.40%,特异度为50.00%。结论胸部定量CT扫描参数Pi10能够帮助预测COPD患者治疗反应。 展开更多
关键词 慢性阻塞性肺疾病 胸部定量ct 治疗反应 预测因素
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基于定量CT身体组分、^(18)F-FDG PET/CT显像预测手术联合新辅助化疗治疗早期乳腺癌预后的价值
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作者 白丽 苏雪娟 陈体 《海南医学》 CAS 2024年第5期713-718,共6页
目的 分析定量CT (QCT)身体组分、^(18)F-氟脱氧葡萄糖正电子发射型计算机断层显像(^(18)F-FDG PET-CT)对手术联合新辅助化疗(NAC)治疗早期乳腺癌患者预后的预测效能,为临床治疗提供参考。方法 选取2020年3月至2022年10月于南阳市第二... 目的 分析定量CT (QCT)身体组分、^(18)F-氟脱氧葡萄糖正电子发射型计算机断层显像(^(18)F-FDG PET-CT)对手术联合新辅助化疗(NAC)治疗早期乳腺癌患者预后的预测效能,为临床治疗提供参考。方法 选取2020年3月至2022年10月于南阳市第二人民医院接受手术联合NAC治疗的82例早期乳腺癌患者纳入研究,在NAC前和化疗1、3个周期后检测记录QCT参数[L_(1)、L_(2)水平的皮下脂肪面积(SFA)、内脏脂肪面积(VFA)、骨密度(BMD)、L_(3)水平的椎旁肌肉面积(TMA)]、^(18)F-FDG PET/CT显像的最大标准摄取值(SUV_(max))、肿瘤代谢体积(MTV)。NAC结束后进行手术,随访12个月(失访2例),依据有无复发转移分为预后良好组43例和预后不良组37例,比较不同预后患者的QCT参数、^(18)F-FDG PET/CT显像指标,采用受试者工作特征(ROC)曲线获取曲线下面积(AUC)分析其对早期乳腺癌患者预后的预测效能。结果化疗1个周期后,预后良好组患者的SFA、BMD、VFA、MA水平分别为(45.23±4.07) cm^(2)、(128.97±26.53) mg/m^(2)、(78.07±6.69) cm^(2)、(37.36±5.74) cm^(2),明显高于预后不良组的(42.52±3.32) cm^(2)、(112.54±25.82) mg/m^(2)、(73.73±7.25) cm^(2)、(32.94±5.31) cm^(2),差异均有统计学意义(P<0.05);化疗3个周期后,预后良好组患者的SFA、BMD、VFA、MA水平分别为(40.95±3.92) cm^(2)、(113.55±15.87) mg/m^(2)、(73.59±6.17) cm^(2)、(32.67±4.98) cm^(2),明显高于预后不良组的(37.51±3.56) cm^(2)、(95.18±17.45) mg/m^(2)、(70.30±5.14) cm^(2)、(28.52±4.42) cm^(2),差异均有统计学意义(P<0.05);化疗1个周期后,预后良好组患者的SUV_(max)、MTV分别为5.43±1.25、(3.86±0.87)×10^(4)mm,明显低于预后不良组的6.04±1.07、(4.27±0.85)×10^(4)mm,差异均有统计学意义(P<0.05);化疗3个周期后,预后良好组患者的SUV_(max)、MTV分别为3.94±1.06、(2.61±0.70)×10^(4)mm,明显低于预后不良组的4.73±1.21、(3.05±0.93)×10^(4)mm,差异均有统计学意义(P<0.05);经ROC曲线分析结果显示,SFA、BMD、VFA、MA、SUV_(max)、MTV联合预测手术联合NAC治疗早期乳腺癌患者预后的AUC分别为0.898 (95%CI:0.809~0.954)、0.919 (95%CI:0.836~0.968)。结论 NAC过程中检测QCT参数、^(18)F-FDG PET/CT显像指标可预测手术联合NAC治疗早期乳腺癌患者的预后,联合预测的价值较高。 展开更多
关键词 乳腺癌 ^(18)F-氟脱氧葡萄糖正电子发射型计算机断层显像 定量ct 新辅助化疗 骨密度 肿瘤代谢体积
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