Analysis of The Value of Multi-Slice Spiral CT and Magnetic Resonance Imaging in The Diagnosis of Carpal Joint Injury

Objective:To analyze the value of multi-slice spiral computed tomography(CT)and magnetic resonance imaging(MRI)in the diagnosis of carpal joint injury.Methods:A total of 130 patients with suspected wrist injuries admitted to the Department of Orthopedics of our hospital from January 2023 to January 2024 were selected and randomly divided into a single group(n=65)and a joint group(n=65).The single group was diagnosed using multi-slice spiral CT,and the joint group was diagnosed using multi-slice spiral CT and magnetic resonance imaging,with pathological diagnosis as the gold standard.The diagnostic results of both groups were compared to the gold standard,and the diagnostic energy efficiency of both groups was compared.Results:The diagnostic results of the single group compared with the gold standard were significant(P<0.05).The diagnostic results of the joint group compared with the gold standard were not significant(P>0.05).The sensitivity and accuracy of diagnosis in the joint group were significantly higher than that in the single group(P<0.05).The specificity of diagnosis in the joint group was higher as compared to that in the single group(P>0.05).Conclusion:The combination of multi-slice spiral CT and MRI was highly accurate in diagnosing wrist injuries,and the misdiagnosis rate and leakage rate were relatively low.Hence,this diagnostic program is recommended to be popularized.

Three-dimensional Imaging of Multi-slice Spiral CT in Bronchial Artery Correlative Study on Blood Supply of Central Lung Cancer and Its Clinical Significance

Objective: To evaluate three-dimensional bronchial artery imaging charactersin central lung cancer and applied values with multi-slice spiral CT (MSCT) to provide theoreticalevidence on blood supply and intervention therapy. Methods: Eighteen patients with central lungcancer underwent MSCT with real time helical thin-slice CT scanning. Three-dimensional bronchialartery reconstruction was done at the console work-station. The space anatomical characters ofbronchial artery were observed through different rotations. Results: For 6 cases, thethree-dimensional images of bronchial artery (33.33%) could exactly show the origins, the routes(lung inner segment and mediatism segment) and the diameters of bronchial arteries. Vision rate ofbronchial arteries was the highest in pulmonary artery stricture and truncation groups, and thevessels' diameter became larger apparently. These characters demonstrated blood supply of this kindof central lung cancer come from bronchial artery. Volume rendering images were the best ones amongthree-dimensional images. Conclusion: Three-dimensional imaging with MSCT in bronchial artery canreveal the anatomical characters of bronchial artery and provide theoretical evidence on bloodsupply and intervention therapy of central lung cancer.

Multi-slice Spiral CT Three-dimensional Portography in Portal Vein Tumor Thrombus of Hepatic Cancer

Objective: To study the clinical significance of multi-slice spiral CT 3-dimensional (3D) portography in portal vein tumor thrombosis of hepatocellular cacinoma.Methods: 57 cases undergoing 3D portography were collected, of which 6 cases were normal, 5 cases were subjected to cirrhosis and hypertension of portal vein, 42 cases had portal tumor thrombus of hepatic cancer, and the remaining 4 cases showed lymph node enlargment in hilar of liver. All data of the patients came from conventional multi-slice spiral CT double phase of liver. Contrast media was 1.5–2 ml/kg with the injection rate being 2.5–3 ml/s. Axis and 3D portography was analyzed and compared in 42 cases of portal tumor thrombus of hepatic cancer.Results: According to portal tumor thrombus position, 42 cases were fallen into three categories: left (13 cases), right (20 cases), main (9 cases) of potal vein. There was no difference between axis and 3D portography in displaying portal tumor thrombus of hepatic cancer (P>0.05), but 3D portography showing collateral branches was better than axis portography after main portal vein thrombus.Conclusion: Multi-slice spiral CT 3D portography can display the position and types of portal tumor thrombus of hepatic cancer. 3D combined with axis portography can better evaluate the portal tumor thrombus of hepatic cancer and guide to select the therapies. Key words portal vein - tumor thrombus - multi-slice CT - 3 dimension imaging

Multi-slice spiral CT angiography in evaluating donors of living-related liver transplantation

BACKGROUND: During the past years, the number of liver transplantation has increased greatly, but the number of available organs has not increased. In view of the critical shortage of organs, the indications for living-related liver transplantation (LRLT) have broadened since experience with the procedure has been achieved. This study was undertaken to assess the value of multi-slice spiral CT (MSCT) angiography in evaluating the hepatic arterial and veinous anatomy of potential donors for LRLT. METHODS: MSCT was performed after intravenous injection of contrast material at 3 ml/s. The total dose was calculated as 2 ml/kg. Twenty LRLT donors (2 men and 18 women) were subjected to MSCT angiography of hepatic blood vessels. These were generated by volume rendering and maximum intensity projection, while curved planar reformation was added in 5 patients. RESULTS: We identified 10 important hepatic vascular variants in 9 of the 20 donors (4 arterial, 4 venous, and 2 portal venous variants). In hepatic arterial variants, two had a replaced right hepatic artery arising from the superior mesenteric artery, an accessory right hepatic artery from the superior mesenteric artery and a replaced left hepatic artery arising from the left gastric artery. In hepatic venous variants, three had an accessory inferior right hepatic vein and one had two accessory inferior right hepatic veins. In hepatic portal venous variants, two had trifurcation of the main portal vein. CONCLUSIONS: As a non-invasive and reliable method, MSCT angiography is of value in the clinical evaluation of LRLT donors. MSCT angiography should be recommended as a routine preoperative examination for potential LRLT donors.

Study on the combined value of multi-slice spiral CT in the diagnosis of elderly colorectal cancer colorectal cancer tumor markers

Objective:To investigate the value of tumor markers in colorectal cancer with multi-slice spiral CT in the diagnosis of elderly colorectal cancer.Methods:From January 2016 to September 2017 year period, 73 elderly patients with colorectal cancer treated in our hospital were selected as observation group;64 elderly patients with intestinal benign lesions were selected as control group during the same period. Serum samples were collected to detect contents of CEA, CA72-4, CA19-9 and CYFRA21-1 by Roche luminous immunoassay analyzer, and multi slice spiral CT was used.Results:Serum levels of CEA, CA72-4, CA19-9 and CYFRA21-1 levels of the observation group were significantly higher than that of the control group;the positive rate of CEA, CA72-4, CA19-9, CYFRA21-1 and their combined detection were all significantly higher than that of the control group;positive rate of MSCT in the observation group was higher than the control group;positive rates of tumor markers combining with MSCT examination of colorectal cancer were higher than that of combined detection of tumor markers and MSCT examination;but there was no significant difference in positive rate of combined detection of tumor markers and the positive rate of MSCT detection of colorectal cancer.Conclusion:Colorectal cancer tumor markers combined with multi-slice spiral CT in the diagnosis of colorectal cancer in elderly has important research value, can significantly improve the positive rate of diagnosis.

Establishing models of portal vein occlusion and evaluating value of multi-slice CT in hepatic VX2 tumor in rabbits

AIM： To establish models of portal vein occlusion of hepatic VX2 tumor in rabbits and to evaluate the value of multi-slice CT. METHODS： Forty New Zealand rabbits were divided into 4 groups according to digital table： Immediate group （group A; transplantation of tumor immediately after the portal vein occlusion）, 3-wk group （group B; transplantation of tumor at 3 wk after the portal vein occlusion）, negative control group （group C） and positive control group （group D）, 10 rabbits in each group. Hepatic VX2 tumor was transplanted with abdominalembedding innoculation immediately after the portal vein occlusion and at 3 wk after the portal vein occlusion. Meanwhile, they were divided into negative control group （Left external branch of portal vein was occluded by sham-operation, and left exite was embedded and inoculated pseudoly） and positive control group （Transplanted tumor did not suffer from the portal vein occlusion）. All rabbits were scanned with multi-slice CT. RESULTS： All 40 animals were employed in the final analysis without death. Tumor did not grow in both immediate group and 3-wk group. In 3-wk group, left endite was atrophied and growth of tumor was inhibited. The maximal diameter of tumor was significantly smaller than that in positive control group （2.55±0.46 vs 3.59±0.37 cm, t = 5.57, P 〈 0.001）. Incidences of metastasis in the liver and lung were lower in 3-wk group than those in positive control group （10% vs 400, and 90% vs 100%, respectively）. The expression intensities of the vascular endothelium growth factor （VEGF） in groups A, B, C and D were 0.10±0.06, 0.66±0.21, 0.28±0.09 and 1.48±0.32, respectively. VEGF expression level in the test group A was significantly lower than that in the negative control group C （t = 5.07; P 〈 0.001）.In addition, VEGF expression in the test group B was significantly lower than that in the positive control group D （t = 6.38; P 〈 0.001）. Scanning with multi-slice CT showed that displaying rate of hepatic artery branches was obviously lower in grade Ⅲ（40%） than that in grade Ⅰ（70%） and Ⅱ（100%） （P 〈 0.05）; but there was no significant difference in displaying rate of the portal vein at various grades. Values of blood flow （BF） of the liver, blood volume （BV）, mean transit time （MTT） and permeability of vascular surface （PS） were lower in the immediate group and 3-wk group than those in control groups, but values of hepatic arterial fraction （HAF） were increased. Significant positive correlations were existed between BF and BV （r = 0.905, P 〈 0.01）, and between BF and PS （r = 0.967, P 〈 0.01）, between BV and PS （r = 0.889, P 〈 0.01）. A significant negative correlation existed between PV and HAF （r = -0.768, P 〈 0.01）, between PS and HAF （r = -0.557, P 〈 0.01）. The values of BF, BV and PS had a positive correlation with VEGF （rBF = 0.842, rBV = 0.579, rPS = 0.811, P 〈 0.01） . However, there was no significant correlation between the values of MTT and HAF and the VEGF expression （rMTt = 0.066, rHAF = -0.027）. CONCLUSION： Ligating the left external branch of portal vein is an ideal way to establish models of portal vein occlusion in rabbits with hepatic VX2 tumor. Multi slice CT plays a key role in evaluating effect of portal vein occlusion.

Value of Multi-slice Spiral CT in the Diagnosis and Resectability of Pancreatic Cancer

Objective:To analyze the value of multislice spiral CT in the diagnosis and resectability of pancreatic cancer.Method:56 patients with pancreatic cancer treated in our hospital from January 2018 to October 2019 were selected as the research subjects.All patients underwent multi-phase scanning by multislice spiral CT.According to the results of the images,observe whether the pancreatic cancer has affected the blood vessels surrounding the pancreas,evaluate the resectability based on the results of the examination,and analyze the final results of the operation which was taken as the standard.Results:all the 56 cases presented slightly low density or equal density,and 28 cases had complete outline.Multi-slice spiral assessment of patients’vascular invasion types found that 192 branches can be resected with 70 branches cannot;Multi-slice spiral assessment of the main arterial and venous invasion grades around the pancreas of the patients found that 212 branches can be resected with 50 branches cannot;Multi-slice spiral CT was used to evaluate the resectability of pancreatic cancer compared with surgical results.The accuracy of resectable types of vascular invasion was 72.52%;the accuracy of resectable vascular invasion grades was 79.39%.Conclusion:the application of multi-slice spiral CT in the diagnosis of pancreatic cancer can provide a clear understanding of the condition of vascular invasion and distant metastasis,and the accuracy of assessing resection can reach more than 70.00%,which provides a reference for clinical application.

Comparison of the Imaging Manifestations and Diagnostic Values of Multi-slice Spiral CT and Enhanced MRI Scans of Primary Liver Cancer(PLC)Intrahepatic Lesions

Objective:To compare and analyze the clinical diagnostic value of multi-slice spiral CT and enhanced MRI for primary liver cancer(PLC),and to summarize the imaging findings.Methods:The research subjects in this article were 50 patients with PLC who were admitted to our hospital from 2017 April to 2018 September.After the patients were admitted,they were examined by multi-slice spiral CT and enhanced MRI scanning,and the pathological diagnosis results were followed up.Relevant information was reviewed and analyzed.Results:The detection rate of multi-slice spiral CT was higher than that of MRI in the portal venous phase lesion detection.The difference was statistically significant(P<0.05).The detection rate of lesions in the arterial phase and delayed phase was not statistically significant(P>0.05);the diagnostic accuracy of multi-slice spiral CT was 85.96%,and the diagnostic accuracy of enhanced MRI scanning was 91.11%,which was not statistically significant(P>0.05).MRI scans showed the capsules of primary liver cancer better than CT,but the difference was not statistically significant(P>0.05).Conclusion:In conclusion,both multi-slice spiral CT and enhanced MRI can be used for the effective diagnosis of primary liver cancer intrahepatic lesions.The diagnostic value of the two is equivalent,but enhanced MRI has a slightly higher diagnostic accuracy and can be used as the preferred method.

西门子Force双源CT故障维修案例分析与探讨

西门子Force双源CT属于高端CT,设备整体配置高、性能佳、应用范围广、稳定性好,在医院运行中发挥了巨大作用。由于设备使用量大,故障时有发生,且设备集成程度较高、整体维修难度大。本文详细分析了使用过程中发生的水冷系统、患者检查床、探测器电源3例故障的故障排除过程,并通过更换三通阀、维护升降电机轴承、焊接X10接头解决故障,节省了维修费用,并为同行维修此类故障提供参考。

基于探测器响应机理的碳/碳构件CT图像环状伪影的校正方法

在碳/碳复合材料的计算机断层扫描(CT)中,由于探测器单元的响应非线性及不一致性导致重建图像出现严重的环状伪影,干扰图像中缺陷的检出,影响检测系统对被检构件的质量评价。结合碳/碳复合材料组分单一且密度均匀的特点,提出了一种基于探测器响应机理的CT图像环状伪影的校正方法,利用采集的劣化投影数据做预重建,对重建结果做阈值分割以获得被检测物体的三维模型。结合已知的材料和密度信息,对被检物体进行重投影,得到投影数据的理论值与实测值之间的映射关系,用于探测器响应校正以优化检测图像。与传统低通滤波的环状伪影校正方法相比,该方法考虑了环状伪影的物理成因并充分利用了检测对象的先验信息。研究结果表明,该校正方法在保留图像细节和纹理的同时,能够有效减少环状伪影,提升图像质量,消除伪影对于图形中缺陷识别的干扰,为提升检测系统对碳/碳复合材料构件缺陷的检出能力提供理论依据。

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

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。

工业CT大视野扫描的统一形式及其重建算法

工业CT大视野扫描模式包括探测器偏置扫描和转台偏置扫描。实际应用中,大视野扫描通常同时存在探测器偏置和转台偏置。针对上述情况,本文提出了大视野扫描的统一形式,即探测器、转台联合偏置扫描。通过分析投影地址的重复采样次数,本文提出基于Parker函数加权的联合偏置重建算法,并对一个考古文物进行大视野扫描实验进行验证。实验结果表明,本文提出的大视野扫描统一模型及其重建算法切实可行,具有一定的工程实用价值。

Relation between Epicardial Adipose Tissue Thickness Assessed by Multidetector Computed Tomography and Significance of Coronary Artery Disease

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.

A practical image reconstruction and processing method for symmetrically off-center detector CBCT system

CBCT scanners have been widely used in angiography,radiotherapy guidance,mammography and oral maxillofacial imaging.To cut detector size,reduce manufacturing costs and radiation dose while keeping a reasonable FOV,the flat panel detector can be placed off-center horizontally.This scanning configuration extends the FOV effectively.However,each projection is transversely truncated,bringing errors and artifacts in reconstruction.In this paper,a simple but practical method is proposed for this scanning geometry based on truncation compensation and the modified FDK algorithm.Numerical simulations with jaw phantom were conducted to evaluate the accuracy and practicability of the proposed method.A novel CBCT system for maxillofacial imaging is used for clinical test,which is equipped with an off-center small size flat panel detector.Results show that reconstruction accuracy is acceptable for clinical use,and the image quality appears sufficient for specific diagnostic requirements.It provides a novel solution for clinical CBCT system,in order to reduce radiation dose and manufacturing cost.

对比剂分次团注联合能量成像获得CTU和CTA联合成像的应用研究

目的:探讨对比剂分次团注结合双层探测器光谱CT 50 keV虚拟单能量图像(VMI),在CT泌尿系成像(CTU)与主动脉CTA联合成像中的应用价值。方法:收集2024年3月至4月在首都医科大学附属北京同仁医院Philips IQon双层探测器光谱CT行CTU检查患者32例为试验组。使用对比剂分次团注及团注追踪技术;扫描后重建常规120 kVp混合能量图像为A1组;光谱重建获得50 keV VMI为A2组。收集2023年12月至2024年3月间在相同设备行CTU检查患者32例为对照组,使用对比剂分离团注技术及团注追踪技术;扫描后重建常规120 kVp混合能量图像为B组。客观评价包括:比较3组腹主动脉、双侧肾动脉的CT值、对比噪声比(CNR)、信噪比(SNR);比较输尿管起始部平均CT值和中下部平均CT值,并采用Kruskal-Wallis检验,采用Nemenyi检验进行两两比较。试验组与对照组的有效辐射剂量比较采用Wilcoxon检验。主观评价由两名高年资影像医师分别对3组CTA及CTU图像进行4分法和3分法评价,两名医师主观评分的一致性采用Kappa检验。结果:客观评价指标中,A2组分别与A1组和B组比较,均有统计学差异;A1组与B组仅双侧肾动脉SNR有统计学差异。两组有效辐射剂量有统计学差异,试验组较对照组降低15.1%。3组CTA、CTU图像主观评价无统计学差异;两名医师对CTA图像评分结果一致性非常好,对CTU图像评分结果一致性好。结论:利用对比剂分次团注行CTU检查时,获得泌尿系及主动脉同时显影的融合图像,不仅具有明确的解剖关系及相同的图像质量,而且降低有效辐射剂量;光谱重建获得的50 keV虚拟单能量图像,优化CTU及CTA图像质量,具有临床价值。

Dual-Energy X-Ray Computed Tomography Scanner Using Two Different Energy-Selection Electronics and a Lutetium-Oxyorthosilicate Photomultiplier Detector

To obtain two kinds of tomograms at two different X-ray energy ranges simultaneously, we have constructed a dual-energy X-ray photon counter with a lutetium-oxyorthosilicate photomultiplier detector system, three comparators, two microcomputers, and two frequency-voltage converters. X-ray photons are detected using the detector system, and the event pulses are input to three comparators simultaneously to determine threshold energies. At a tube voltage of 100 kV, the three threshold energies are 16, 35 and 52 keV, and two energy ranges are 16 - 35 and 52 - 100 keV. X-ray photons in the two ranges are counted using microcomputers, and the logical pulses from the two microcomputers are input to two frequency-voltage converters. In dual-energy computed tomography (CT), the tube voltage and current were 100 kV and 0.29 mA, respectively. Two tomograms were obtained simultaneously at two energy ranges. The energy ranges for gadolinium-L-edge and K-edge CT were 16 - 35 and 52 - 100 keV, respectively. The maximum count rate of dual-energy CT was 105 kilocounts per second with energies ranging from 16 to 100 keV, and the exposure time for tomography was 19.6 min.

光谱CT显示左结肠动脉的最佳虚拟单能量

目的:探讨双层探测器光谱CT显示左结肠动脉(LCA)的最佳虚拟单能量,旨在为腹腔镜直肠癌根治术前评估LCA提供帮助。方法:回顾性分析在本院行腹部CT血管成像(CTA)扫描的100例患者的影像学资料,将动脉期原始图像重组成混合能量图像以及基于能谱的间隔10 keV的40~70 keV的单能量图像。对5组图像LCA的CT值、信噪比(SNR)、对比噪声比(CNR)、图像噪声以及图像质量评分进行比较。结果:40~70 keV组单能量图像LCA的CT值、噪声、CNR、SNR随着能级的升高呈递减趋势。常规混合能量图像组及40~70 keV单能量图像组两两比较,各组间CT值、SNR、CNR、噪声差异有统计学意义(P<0.05)。40 keV组图像LCA的CT值、CNR、SNR均高于其他组,噪声低于常规混合能量图像组。两名影像科医师图像质量主观评价的一致性良好(0.40≤Kappa值<0.75),各组间图像主观评分差异均有统计学意义(P均<0.001)。40 keV组图像主观评分最高,40~70 keV组单能量图像质量均高于常规混合能量图像。结论:40 keV为显示LCA的最佳虚拟单能量,显示血管清晰、边缘锐利,能更清晰显示LCA及其解剖变异,利于外科医生腹腔镜直肠癌根治术的顺利进行。

双层探测器光谱CT虚拟单能量CTA技术对脑血管成像的价值

目的:探讨双层探测器光谱CT虚拟单能量(VMI)(≤70 keV)CTA技术对脑小血管成像的应用价值。方法:回顾性分析在Philips IQon CT行头颈部CTA检查的52例患者的影像资料,获得常规120 kVp混合能量图像和光谱数据重建的40~70 keV(间隔10 keV)CTA图像。测量大脑中动脉M1段的CT值、信噪比(SNR)、对比噪声比(CNR)和同层面血管旁脑实质的CT值和噪声(SD),并由两名医师以5分法分别对中大脑中动脉的容积再现(VRT)图像和豆纹动脉的最大密度投影(MIP)图像评分并进行比较。结果:于40~70 keV VMI测得的血管CT值、SNR、CNR随着能级降低显著递增,SD值仅稍增,与常规图像相比差异多有统计学意义;主观评价中,40 keV和50 keV组VRT图像评分为5(5,5)、5(4,5);MIP图像评分为4(3,4)、4(3,5),两组主观评分均优于其他组,两组间差异均无统计学意义。结论:双层探测器光谱CT小于70 keV的虚拟单能量CTA技术可以有效提高脑血管远端分支和豆纹动脉的显示效果,常规推荐50 keV VMI。

光谱CT多定量参数对胃癌Lauren分型的诊断价值

目的:探究双层探测器光谱CT多定量参数术前对胃癌Lauren分型的诊断价值。方法:收集48例术前在双层探测器光谱CT上行腹部增强检查且术后病理确诊为胃腺癌的患者,获取双层探测器光谱CT多定量参数及术后病理资料。按Lauren分型将入组病例分为三组,其中弥漫型17例,混合型21例,肠型10例。通过后处理软件得到碘浓度图及有效原子序数图,测量胃癌病灶及同层面腹主动脉期及静脉期的碘浓度及有效原子序数,计算标准化碘浓度及标准化有效原子序数。比较增强各期不同分型间各参数值的差异,对有统计学意义的参数绘制其受试者工作特征(receiver operating characteristic,ROC)曲线评估各参数的诊断效能,按约登指数为最大原则得出诊断阈值及曲线下面积(area under curve,AUC)。结果:弥漫型胃癌的各项参数值均高于肠型及混合型胃癌,弥漫型与混合型、弥漫型与肠型差异均具有统计学意义(P<0.05),而混合型与肠型除动脉期标准化有效原子序数差异具有统计学意义(P<0.05)外,余各参数值差异均无统计学意义(P>0.05)。动脉期及静脉期碘浓度、标准化碘浓度、有效原子序数及标准化有效原子序数诊断弥漫型胃癌的AUC分别为0.758、0.819、0.739、0.861及0.889、0.825、0.832、0.881;诊断阈值分别为1.26、0.12、7.91、0.75及1.81、0.52、8.28、0.91;动静脉期碘浓度、标准化碘浓度中,静脉期AUC最大;动静脉期有效原子序数、标准化有效原子序数中,静脉期AUC最大。结论:双层探测器光谱CT碘浓度及有效原子序数可为术前鉴别胃癌Lauren分型提供更多信息,具有一定的临床价值。

基于ATCM技术的不同探测器宽度对头颈CT血管成像图像质量与辐射剂量影响的研究

目的基于自动管电流调制(Automatic Tube Current Modulation,ATCM)技术探讨不同探测器宽度对头颈CT血管成像(CT Angiography,CTA)图像质量和辐射剂量的影响。方法选取2022年6月至2023年5月于阳光融和医院就诊的共120例头颈CTA检查图像资料和临床资料为研究对象,将其按照不同探测器宽度分为A组(40 mm)和B组(80 mm),A组60例,B组60例,其中体重正常、超重、肥胖患者各20例,分别比较不同探测器宽度扫描条件下的图像质量及其辐射剂量。结果不同探测器宽度下正常、超重、肥胖患者头颈图像质量-噪声比差异均无统计学意义(P>0.05);不同探测器宽度下体重正常、超重、肥胖患者头颈图像质量-CT值差异均无统计学意义(P>0.05);40 mm探测器宽度螺旋扫描体重正常、超重、肥胖患者的剂量长度乘积均低于80 mm探测器宽度螺旋扫描,差异有统计学意义(P<0.05)。结论基于ATCM技术选择40 mm探测器宽度可保证头颈CTA图像质量,同时减少辐射剂量。