Effect of experimental warming on soil respiration under conventional tillage and no-tillage farmland in the North China Plain

Understanding the response of soil respiration to global warming in agro-ecosystem is crucial for simulating terrestrial carbon （C） cycle. We conducted an infrared warming experiment under conventional tillage （CT） and no-tillage （NT） farmland for winter wheat and summer maize rotation system in North China Plain （NCP）. Treatments include CT with and without warming （CTW and CTN）, NT with and without warming （NTW and NTN）. The results indicated that warming had no sig- nificant effect on soil moisture in irrigated farmland of NCP （P〉0.05）. The elevated average soil temperature of 1.1-116℃ in crop growing periods could increase annual soil CO2 emission by 10.3% in CT filed （P〉0.05）, but significantly increase it by 12.7% in NT field （P〈0.05）, respectively. The disturbances such as plowing, irrigation and precipitation resulted in the obvious soil CO2 emission peaks, which contributed 36.6-40.8% of annual soil cumulative CO2 emission. Warming would enhance these soil CO2 emission peaks; it might be associated with the warming-induced increase of autotrophic respiration and heterotrophic respiration. Compared with un-warming treatments, dissolved organic carbon （DOC） and soil microbial biomass carbon （MBC） in warming treatments were significantly increased by 11.6-23.4 and 12.9-23.6%, respectively, indicating that the positive responses of DOC and MBC to warming in both of two tillage systems. Our study highlights that climate warming may have positive effects on soil C release in NCP in association with response of labile C substrate to warming.

Differentiation of Soil Fauna Populations in Conventional Tillage and No-Tillage Red Soil Ecosystems

In a field experiment, the populations of major soil fauna groups including earthworms, enchytraeids,arthropods and nematodes were examined in conventional tillage (CT) and no-tillage (NT) red soil ecosystems to evaluate their responses to tillage disturbance. Earthworms, macrry and micro-arthropods were stimulated under NT with earthworms showing the highest population increase by four times, while enchytraeids and nematodes favored CT system, predicting certain adaptability of these animals to plow-disturbed soil environment. On the basis of relative response index it was found that soil fauna was more sensitive to tillage than soil resource base (C and N pools) and microflora. The population structure of soil fauna was also affected by tillage treatments. Analysis on nematode trophic groups showed that bacteria-feeding and plant parasitic nematodes were more abundant in CT soil whereas the proportions of fungivores and omnivorepredators increased in NT soil. Possible reasons for the differentiation in both size and structure of the fauna population were discussed and the ecological significance involved in these changes was emphasized.

CT常规扫描与CT小肠造影对小肠肿瘤的诊断价值比较

目的分析CT常规扫描与CT小肠造影对小肠肿瘤的诊断价值。方法选取2019年11月至2021年10月赣南医学院兴国医院的35例疑似小肠肿瘤患者作为研究对象,以病理检查结果为金标准,比较128层螺旋CT常规扫描与128层螺旋CT小肠造影诊断小肠肿瘤的准确度、敏感度、特异度、阳性预测值、阴性预测值,并对比两种检查方式对各类型小肠肿瘤疾病的检出率。结果病理检查结果显示,35例疑似小肠肿瘤疾病患者中,阳性32例,阴性3例。32例阳性患者中,小肠脂肪瘤15例,小肠平滑肌瘤12例,腺瘤5例。CT小肠造影对小肠肿瘤疾病的诊断准确度为94.29%、敏感度为96.88%,CT常规扫描的诊断准确度为71.43%,敏感度为75.00%,CT小肠造影高于CT常规扫描,差异有统计学意义(P<0.05);CT小肠造影对小肠肿瘤疾病诊断的特异度为100.00%,阳性预测值为96.88%,阴性预测值为66.67%,CT常规扫描特异度为50.00%,阳性预测值为88.89%,阴性预测值为12.50%,两种检查方式比较差异无统计学意义(P>0.05)。两种检查方式对各类型小肠肿瘤疾病的检出率比较,差异无统计学意义(P>0.05)。结论对于小肠肿瘤患者,与CT常规扫描相比,CT小肠造影检查准确度、敏感度更高,诊断效能显著。

基于CT扫描研究颗粒形状对砂土力学性质的影响

为了探究颗粒形状对砂土力学性质的影响,选取玻璃珠、石英砂、玻璃渣3种颗粒形状差异较大的砂土作为研究对象。首先通过计算机断层(computed tomography,CT)扫描重构了3种砂土的三维结构,选取了伸长率(EI)、扁度(FI)、球度(S)3个表征颗粒形状参数的均值作为砂土颗粒整体形状参数(overall regularity,OR),并对整体形状参数OR进行统计分析。然后配制7种不同形状参数的砂土进行了常规三轴压缩试验得到了其力学强度参数,研究砂土颗粒形状对其力学强度的影响规律。结果表明:7种砂土的应力-应变曲线均为应变软化型,都呈现出先剪缩后剪胀的特性;整体形状参数OR能较好反映砂土的力学特征,即随着整体形状参数OR的减小,应变软化现象变得不明显,但其峰值偏应力呈增大的趋势;砂土的内摩擦角随整体形状参数OR的减小呈线性增长,表观黏聚力急剧增大,但最大剪胀角随OR的减小而减小。此外,将临界内摩擦角与整体形状参数OR进行线性拟合,得到了两者较好的线性关系。

CT虚拟定位与传统定位在肺癌早期切除术中的应用价值

目的:研究CT虚拟定位与传统定位在肺癌早期切除术中的应用价值,以期弥补传统定位的不足,为相关研究提供借鉴。方法:回顾性选取2021年1月-2023年5月医院治疗的100例肺癌患者作为研究对象,根据基线资料可比性原则,以治疗方式的不同划分为观察组(CT虚拟定位,62例)和对照组(常规CT定位,38例)。比较两组患者定位效果,包括定位成功、精准切除、定位耗时、手术时间、切除时间、住院时间等。比较两组患者的定位相关并发症、术后相关并发症。结果:观察组定位耗时、手术时间、住院时间、切除时间低于对照组,定位成功、精准切除发生率高于对照组,差异显著,具有统计学意义(P<0.05)。观察组肺部出血、穿刺部位疼痛、刺激性咳嗽发生率均低于对照组,并发症事件种类数少于对照组,差异有统计学意义(P<0.05)。观察组皮下气肿、液气胸、肺栓塞、手术后并发症事件少于对照组,差异有统计学意义(P<0.05)。结论:应用CT虚拟定位相比常规CT定位更具优势,可提高定位的准确性,缩短手术时间,减少相关并发症。

Three-dimensional MR and axial CT colonography versus conventional colonoscopy for detection of colon pathologies

AIM： To evaluate the sensitivity and specificity of MR colonography （MRC） and CT performance in detecting colon lesions, and to compare their sensitivity and specificity with that of conventional colonoscopy. METHODS： Forty-two patients suspected of having colonic lesions, because of rectal bleeding, positive fecal occult blood test results or altered bowel habits, underwent the examinations. After insertion of a rectal tube, the colon was filled with 1000-1500 mL of a mixture of 9 g/L NaCI solution, 15-20 mL of 0.5 mmol/L gadopentetate dimeglumine and 100 mL of iodinized contrast material. Once colonic distension was achieved, three-dimensional gradient-echo （3D-GRE） sequences for MR colonography and complementary MR images were taken in all cases. Immediately after MR colonography, abdominal CT images were taken by spiral CT in the axial and supine position. Then all patients were examined by conventional colonoscopy （CC）. RESULTS： The sensitivity and specificity of MRC for colon pathologies were 96.4% and 100%, respectively. The percentage of correct diagnosis by MRC was 97.6%. The sensitivity and specificity of CT for colon pathologies were 92.8%, 100%, respectively. The percentage of correct diagnosis by CT was 95.2%. CONCLUSION： In detecting colon lesions, MRC achieved a diagnostic accuracy similar to CC. However, MRC is minimally invasive, with no need for sedation or analgesics during investigation. There is a lower percentage of perforation risk, and all colon segments can be evaluated due to multi-sectional imaging availability; intramural, extra-intestinal components of colonic lesions, metastasis and any additional lesions can be evaluated easily. MRC and CT colonography are new radiological techniques that promise to be highly sensitive in the detection of colorectal mass and inflammatory bowel lesions.

Microbial Responses of Soil Fertility to Depth of Tillage and Incorporation of Straw in a Haplic Chernozem in Northeast China

Straw is widely incorporated into soil worldwide,but most studies have concentrated on the effects of straw mulching or incorporation with topsoil.To determine the effect of depth of straw incorporation on bacterial and fungal communities,we established a field experiment in a region in Northeast China with Haplic Chernozems using four treatments:conventional tillage(CT,tillage to a depth of 15 cm with no straw incorporation),straw incorporation with conventional tillage(SCT,tillage to a depth of 15 cm),inversion tillage(IT,tillage to a depth of 35 cm)and straw incorporation with inversion tillage(SIT,tillage to a depth of 35 cm).The soils were managed by inversion to a depth of 15 or 35 cm after harvest.The results show that soil organic carbon content was significantly higher and pH and bulk density were significantly lower in the 15–35 cm layer in IT and SIT than CT and SCT.Fungal abundance was higher with straw incorporation,but fungal diversity was lower in the 0–15 cm layer in SCT and SIT than in CT and IT.Path length in the bacterial network was shorter and connectivity was higher in CT+SCT than in IT+SIT,leading to a more complex ecosystem,and the fungal network had opposite patterns.The key taxa in the phylum Actinobacteriota and Ascomycota in the microbial networks changed dramatically at the genus level following inversion tillage with straw amendment,which may increase bacterial network resistance to environmental disturbances and unstable fungal networks,resulting in large changes in the fungal community involved in the decomposition of recalcitrant straw-derived C and the more efficient acquisition of limiting resources.

Influence of Tillage Practices on Soil Physical Properties and Growth and Yield of Maize in Jabal al Akhdar, Libya

Different tillage practices are used for maize cropping in Libya. Yet, the effects of these practices on soil physical properties and maize growth and yield are not known. The objective of this study was to evaluate the effect of different tillage practices on soil physical properties and maize growth and yield in Libya. A field experiment was conducted in 2009 and repeated in 2010 using three tillage practices (conventional tillage (CT), ridge tillage (RT) and zero tillage (ZT)). Data about soil physical properties (penetration resistance (PR), bulk density (BD), total porosity (TP) and saturated hydraulic conductivity (Ks)) across soil depths, maize growth components (plant height, number of leaves, leaf area index and dry root weight) at 60, 75 and 125 days after planting, and maize yield (grain and stover) at harvest were collected and statistically analyzed in both years. To evaluate the effects of the tillage practices economically, the tillage operation cost and production cost were calculated. The results showed that at the surface layer (0 - 20 cm), CT had lower PR and lower BD, but higher TP and Ks compared to RT and ZT. At 20 - 40 cm and 40 - 60 cm depths, the lower PR and PD and higher TP and Ks were under ZT and RT compared to CT. All maize growth parameters at different times were highest for CT followed by RT and lowest for ZT. The CT practice presented the highest grain and stover yield followed by RT and ZT. However, harvest index was higher where ZT was applied. While tillage operation costs were the highest for CT followed by RT and ZT, the production costs were the highest for ZT followed by RT and CT. In general, the CT practice produced higher maize growth and yield, lower production cost, and higher tillage operation cost than those are planted using RT and ZT practices.

Comparison of myocardial perfusion scintigraphy and computed tomography (CT) angiography based on conventional coronary angiography

Coronary artery disease is one of the most common and important health problems in the world. Early diagnosis of this disease is very important to treat before severe myocardial damage occurred. Myocardial perfusion scintigraphy (MPS) and computed tomography coronary angiography (CTCA) which evaluates regional myocardial perfusion and coronary arteries, respectively, are reliable and non-invasive methods in terms of coronary artery disease. In this study we aimed to compare MPS and CTCA based on conventional coronary angiography (CCA). Totally 60 patients were included in the study. CCA and MPS were performed to 30 patients;CCA and CTCA were performed to the rest of the patients (30 patients). Lesions were classified as mild, moderate and severe in these imaging methods. MPS and CTCA were compared with CCA by using chi-square and Fisher’s exact test. MPS and CTCA’s p values were found for left anterior descending artery (LAD) p: 0, p: 0.271;for circumflex artery (Cx) p: 0.256, p: 0.08 and for right coronary artery (RCA) p: 0.033, p: 0.271, respectively. Furthermore MPS and CTCA’s sensitivity, specificity, accuracy, positive predictive value and negative predictive value were calculated 81% to 87%;70% to 49%;73% to 72%;54% to 72%;90% to 71%, respectively. CCA results were found more concordant with MPS for LAD and RCA lesions and more concordant with CTCA for Cx lesions. It was also found that positive predictive value of MPS and negative predictive value of CTCA were significantly higher than the others. As a result, MPS and CTCA were suggested as complementary techniques for the diagnosis of coronary artery disease, not as alternatives to each other.

螺旋CT对肺磨玻璃结节的定性诊断准确性分析

目的探讨分析螺旋CT对肺磨玻璃结节的定性诊断准确性。方法研究对象为160例经病理检查确诊的肺磨玻璃结节患者,对所有患者行常规CT、螺旋CT检查,进行对比,并对良恶性患者不同螺旋CT表现进行分析。结果螺旋CT诊断准确性高于常规CT(P<0.05);螺旋CT检测出的恶性患者其病灶直径、病灶实质大于良性患者(P<0.05);良恶性患者病灶边缘不规则占比对比无统计学差异(P>0.05);恶性患者分叶征、毛刺征、胸膜凹陷占比高于良性患者(P<0.05)。结论对肺磨玻璃结节患者采取螺旋CT检查,所具诊断准确性较大,恶性患者病灶直径、病灶实质较高,且出现分叶征、毛刺征、胸膜凹陷比例较大,可为后续治疗提供一定支持。

磁共振联合常规CT在骨细胞瘤筛检及诊断中的价值探讨

目的:探讨磁共振(MR)联合常规CT在骨细胞瘤筛检及诊断中的应用价值。方法:选取2020年4月-2023年4月我院80例高度疑似骨细胞瘤患者作为研究对象,所有患者均行MR及常规CT检查,分析MR及常规CT的检查结果及影像学表现,以病理学检查结果为金标准,比较MR及常规CT单独及联合检查的结果与金标准的一致性,对比其诊断效能。结果:80例高度疑似骨细胞瘤患者最终确诊阳性66例,阴性14例。病变部位主要集中在股骨远端、胫骨近端、桡骨远端、肽骨近端等位置。MR以边界清晰,T1WI序列不均匀低、等信号,T2WI序列不均匀低、等、高混杂信号为主要征象;常规CT以囊性膨胀破坏区、骨皮质变薄或中断、瘤体内见骨、软组织密度影为主要征象。MR联合常规CT检查与金标准结果具有较好一致性(Kappa=0.726),强于MR或常规CT单独检查(MR Kappa=0.535;常规CT Kappa=0.561)。MR联合常规CT检查对骨细胞瘤诊断的灵敏度、准确度及阴性预测值高于单独MR或者常规CT检查,差异有统计学意义(P<0.05),特异度、阳性预测值高于单独MR或者常规CT检查,差异无统计学意义(P>0.05)。结论:长骨为骨细胞瘤多发部位,MR及常规CT能够较好地呈现骨细胞瘤病变信息,MR在识别骨细胞瘤与周边软组织、神经、血管关系上更具优势,常规CT可以检查出骨质破坏、内部组织侵犯等情况,两者联合使用能够提高诊断灵敏度及准确度,并且可以为医生后续诊治提供综合性参考。

低剂量64排螺旋CT扫描对肺结节的诊断价值分析

目的分析低剂量64排螺旋CT扫描在诊断肺结节上的临床价值。方法88例肺结节患者作为研究对象,均行低剂量64排螺旋CT扫描和常规剂量64排螺旋CT扫描检查。以穿刺活检病理结果为金标准,比较两种检查方法的CT扫描结果,对肺结节的诊断效能,有效辐射剂量和图像质量评分。结果穿刺活检结果显示,88例肺结节患者中恶性结节29例,良性结节59例;低剂量64排螺旋CT扫描检出恶性结节22例、占比75.86%(22/29),良性结节47例、占比79.66%(47/59);常规剂量64排螺旋CT扫描检出恶性结节23例、占比79.31%(23/29),良性结节49例、占比83.05%(49/59)。低剂量与常规剂量64排螺旋CT扫描的准确度、灵敏度、特异度、阳性预测值及阴性预测值比较,差异无统计学意义(P>0.05)。低剂量64排螺旋CT扫描的有效辐射剂量(7.55±1.21)mSv低于常规剂量64排螺旋CT扫描的(13.82±2.22)mSv,差异有统计学意义(P<0.05);两种检查方法图像质量评分比较差异无统计学意义(P>0.05)。结论与常规剂量64排螺旋CT扫描相比,低剂量64排螺旋CT扫描对肺结节的诊断准确度较高,诊断效能理想,图像质量相当,但低剂量64排螺旋CT扫描方案的辐射小,安全性更有保障,建议推广。

16排螺旋CT在腔隙性脑梗死检查诊断中的应用效果

目的:分析16排螺旋CT在腔隙性脑梗死检查诊断中的应用效果。方法:选取2022年8月—2023年8月莲都区人民医院放射科接收的疑似腔隙性脑梗死患者115例为研究对象,均行常规CT和16排螺旋CT检查。以数字减影血管造影诊断结果为“金标准”,分析常规CT和16排螺旋CT的诊断结果、诊断效能、病灶检出率。结果:数字减影血管诊断结果显示,115例患者中,86例确诊为腔隙性脑梗死;常规CT检查显示,92例诊断为腔隙性脑梗死;16排螺旋CT检查显示,87例诊断为腔隙性脑梗死。16排螺旋CT的诊断灵敏度、特异度、阳性预测值和阴性预测值高于常规CT扫查,差异有统计学意义(P<0.05)。16排螺旋CT病灶检出率高于常规CT检查,差异有统计学意义(P<0.001)。结论:16排螺旋CT在腔隙性脑梗死检查诊断中的效果较好,灵敏度、特异度、阳性预测值、阴性预测值和病灶检出率高。

低剂量与常规剂量CT在肺磨玻璃影结节鉴别和浸润性诊断中的应用比较

目的探讨低剂量与常规剂量CT在肺孤立性磨玻璃影结节(GGN)鉴别和浸润性诊断中的应用。方法选取2021年1月至2021年12月在郑州人民医院就诊的120例孤立性GGN患者作为研究对象,均进行低剂量与常规剂量CT扫描检查;比较两种方式在GGN形态学特征检出率、良恶性鉴别及浸润性诊断性能上的差异;比较两种扫描方式的图像质量及扫描辐射剂量差异。结果低剂量与常规剂量CT扫描在GGN的形态学特征(分叶征、毛刺征、空洞征、钙化、血管集束征及胸膜凹陷征)检出率及图像质量等级上均无统计学差异(P>0.05);低剂量CT鉴别GGN良恶性的敏感度、特异性和准确度分别为84.48%、90.32%和87.50%,略低于常规剂量CT的91.38%、93.55%和92.50%;低剂量CT诊断GGN浸润性的敏感度、特异性和准确度分别为76.00%、75.76%和75.86%,低于常规剂量CT的92.00%、90.91%和91.38%。低剂量CT的剂量长度乘积,CT容积剂量指数、有效剂量及有效管球剂量均显著低于常规CT扫描(P<0.05)。结论低剂量与常规剂量CT扫描鉴别肺孤立性GGN良恶性的性能相当,但常规剂量CT对GGN浸润性的诊断性能相对较高,而低剂量CT辐射剂量更低。

Limited impacts of occasional tillage on dry aggregate size distribution and soil carbon and nitrogen fractions in semi-arid drylands

Tillage management that minimizes the frequency and intensity of soil disturbance can increase soil carbon(C)and nitrogen(N)sequestration and improve the resilience of dryland cropping systems,yet the impact of occasional disturbance on soil aggregate formation and the soil organic carbon(SOC)storage within aggregates has not been studied well.We evaluated the effect of four tillage management practices on soil dry aggregate size distribution,aggregate-protected C and N,mineral-associated organic matter carbon(MAOM-C),particulate organic matter carbon(POM-C),and corn(Zea mays L.)and sorghum(Sorghum bicolor(L.)Moench)yields in a semi-arid dryland cropping system.Treatments included conventional tillage(CT),strip-tillage(ST),no-tillage(NT),and occasional tillage(OT)management in a corn-sorghum rotation.Soil macro-aggregates were 51-54%greater under ST,NT,and OT,while small and micro-aggregates were greater in CT.Conventional tillage reduced soil aggregate-associated C by 28-31%in macro-aggregates and 47-53%in small aggregates at 26 months(M)sampling compared to ST,NT,and OT.In clay+silt fraction,CT had 14-16%,21-26%,and 36-43%less SOC at 7,14,and 26M samplings,respectively,than ST,NT,and OT.Aggregate associated N was generally similar under ST,NT,and OT,which was greater on average than CT.Soil MOAM-C and POM-C under ST,NT,and OT were generally greater than respective SOC fractions under CT at 19 and 26 M after OT implementation.Corn and sorghum yields were similar among tillage systems in 2020,but greater under ST,NT,and OT than CT in 2021.Our results suggest that while frequent intensive tillage can lower SOC and N storage,a single stubble mulch occasional tillage after several years of NT does not lead to soil C and N losses and soil structural instability in semi-arid drylands.

Improvements to conventional X-ray tube-based cone-beam computed tomography system

Conventional X-ray tube-based cone-beam computed tomography(CX-CBCT) systems have great potential in industrial applications. Such systems can rapidly obtain a three-dimensional(3D) image of an object.Conventional X-ray tubes fulfill the requirements for industrial applications, because of their high tube voltage and power. Continuous improvements have been made to CX-CBCT systems, such as imaging time shortening,acquisition strategy optimization, and imaging software development, etc. In this study, a CX-CBCT system is developed. Additionally, some improvements to the CX-CBCT system are proposed based on the hardware conditions of the X-ray tube and detector. A near-detector(ND)geometry condition is employed to obtain a sharper image and larger detection area. An improved acquisition strategy is proposed to simplify operations and reduce total imaging time. In the ND geometry condition, a simplified method called FBP slice stacking(SS-FBP) is proposed, which can be applied to 3D image reconstruction. SS-FBP is timesaving relative to traditional methods. Furthermore, imaging software for the CX-CBCT system is developed in the MATLAB environment. Several imaging experiments were performed. The results suggest that the CX-CBCT system works properly, and that the above improvements are feasible and practical.

Tillage and Rice-Wheat Cropping Sequence Influences on Some Soil Physical Properties and Wheat Yield under Water Deficit Conditions

Adopting a better tillage system not only improves the soil health and crop productivity but also improves the environment. A field experiment was conducted to investigate the effects of tillage and irrigation management on wheat (Triticum aestivum L.) production in a post-rice (Oryza sativa L.) management system on silty clay loam soil (acidic Alfisol) for 2003-2006. Four irrigation levels (RF: rainfed;I1: irrigation at crown root initiation (CRI);I2: irrigation at CRI + flowering;I3: irrigation at CRI + tillering + flowering), and two tillage systems (ZT: zero tillage and CT: conventional tillage) were tested. Zero tillage compared to CT, resulted in higher bulk density (1.34 vs 1.23 Mg –3), lower total porosity (48.7 vs 52.9%), higher penetration resistance (1.51 vs 1.37 MPa), lower saturated hydraulic conductivity (1.60 vs 92.0 mm h–1), lower infiltration rate (9.40 vs 36.6 mm h–1) and higher volumetric available water capacity (7.9 vs 7.5%) in the surface 0.15 m soil layer. Irrigation levels significantly affected crop water use, wheat yield, and water use efficiency (WUE). Average total water use was 461, 491, 534 and 580 mm under RF, I1, I2 and I3 treatments, respectively. Grain and straw yield of wheat were statistically the same under ZT and CT during 2003-2004;the values, averaged over four irrigation levels were 2.10 and 2.38 Mg a–1 for grain, and 3.46 and 3.67 Mg a–1 for straw, respectively. Grain yield declined by 22%, 11% and 8% of I3 (2.32 Mg ha–1) with RF, I1 and I2 treatments, respectively, under ZT;and by 13%, 8% and 5% of I3 (2.61 Mg ha–1) with RF, I1 and I2 treatments under CT. Average values of WUE were 4.33 kg ha–1 m–1 and 2.35 m3–1 grain for the ZT and CT treatments. Wheat yield increased with increased irrigation levels for all the cropping seasons. Results from this study concluded that ZT system was better compared to the CT system even with lower yields due to lower input costs for this treatment.

CT尿路造影在输尿管中下段结石诊断中的应用价值分析

目的分析在输尿管中下段结石诊断中应用CT尿路造影的临床价值。方法纳入2021年3月—2023年3月南京医科大学无锡人民医院接受诊治的106例疑似输尿管中下段结石的患者作为研究对象,均给予常规CT和CT尿路造影检查,以手术检查结果为诊断金标准,对常规CT和CT尿路造影的诊断效能,并对比常规CT和CT尿路造影检查诊断输尿管中下段结石的数量、大小和结石部位的符合率。结果CT尿路造影检查的准确率95.28%、灵敏度97.53%、特异度88.00%、阴性预测值91.67%均高于常规CT,差异有统计学意义(χ^(2)=12.266、8.890、3.947、8.619,P<0.05);CT尿路造影检查的阳性预测值高于常规CT,差异无统计学意义(P>0.05);CT尿路造影诊断输尿管中下段结石数量的符合率高于常规CT,差异有统计学意义(P<0.05)。结论CT尿路造影在输尿管中下段结石诊断中的效能良好,可帮助临床明确结石数量、大小和部位,尤其是在微小结石检出方面的符合率较高,可提高诊断的精准性。

对比分析常规增强CT扫描以及能谱CT单能量成像对门静脉血管成像图像质量的影响

目的 对比分析常规增强CT扫描以及能谱CT单能量成像对门静脉血管成像图像质量的影响。方法 方便选取2022年4月—2023年10月于庆阳市人民医院影像中心行门静脉血管成像检查的43例患者为研究对象,均行常规增强CT扫描以及能谱CT单能量成像扫描,比较不同扫描方式CT扫描参数、图像质量客观与主观评估的差异。结果 能谱CT扫描组对比剂碘摄入量、有效辐射量均低于常规组,差异有统计学意义(P均<0.05);两组CTDI_(VOL)水平比较,差异无统计学意义(P>0.05)。能谱CT扫描组门静脉主干、门静脉左支、门静脉右支CT值高于常规组,噪声低于常规组,差异有统计学意义(P均<0.05);两组门静脉内段、门静脉外段CNR比较,差异无统计学意义(P均>0.05)。能谱CT扫描组门静脉血管成像图像主观评分为3~4分占比为97.67%,高于常规组(83.72%),差异有统计学意义(χ^(2)=8.195,P<0.05)。结论 与常规增强CT扫描相比,能谱CT单能量成像可提高门静脉血管成像图像质量,且能减少对比剂摄入和有效辐射量,安全性良好。

探讨胸部低剂量CT扫描技术的临床应用

目的:分析胸部低剂量CT扫描技术的临床应用价值。方法:选取2019年9月—2020年9月郑州市第八人民医院收治的106例肺部疾病患者作为研究对象,按随机数表法分为低剂量组(n=53)与常规剂量组(n=53),低剂量组采用胸部低剂量CT扫描,常规剂量组采用胸部常规剂量CT扫描,对比两组患者图像质量优良率、病灶检出情况、辐射剂量。结果:低剂量组图像质量优良率94.34%(50/53)与常规剂量组98.11%(52/53)相比,差异无统计学意义(χ^(2)=0.260,P>0.05);低剂量组密度不均、空洞、钙化、支气管征、毛刺检出率37.74%(20/53)、20.75%(11/53)、58.49%(31/53)、20.75%(11/53)、35.85%(19/53)与常规剂量组41.51%(22/53)、24.53%(13/53)、60.38%(32/53)、22.64%(12/53)、39.62%(21/53)对比,差异无统计学意义(χ^(2)=0.158、0.215、0.039、0.056、0.161,P>0.05);低剂量组总管球剂量[(1546.98±124.71)mAs]、有效管球剂量[(54.29±4.13)mAs]、放射容积剂量[(4.05±0.52)mGy]少于常规剂量组[(1985.43±141.85)mAs、(73.16±7.28)mAs、(5.91±0.75)mGy],差异有统计学意义(χ^(2)=16.900、16.413、14.837,P<0.05)。结论:在肺部疾病胸部CT检查中,胸部低剂量CT扫描可减少辐射剂量,并能保证图像质量,不会对病灶检出率产生较大影响,应用价值较高。