目的 对比观察经左、右侧肘正中静脉注射对比剂行冠状动脉CT血管成像(CCTA)的图像质量.方法 回顾性分析95例接受CCTA检查患者,其中40例经右侧(右臂组)、55例经左侧(左臂组)肘正中静脉以流率5 ml/s注射对比剂碘佛醇(350 mgI/ml)或碘普罗胺(370 mgI/ml)75 ml;于平静呼吸吸气末屏气行常规序列扫描,对比2组达触发阈值时间、触发浓度及CCTA图像质量.结果 2组CCTA图像质量均满足临床诊断需求(均≥2分).组间达触发阈值时间、触发浓度、冠状动脉平均图像质量得分、主动脉根部图像噪声(S D主动脉),以及血管密度(C T主动脉)、校正后C T主动脉、冠状动脉血管密度(CT冠脉)、校正后CT冠脉、信噪比(SNR)及对比度噪声比(CNR)差异均无统计学意义(P均>0.05),年龄≥55岁患者上述CCTA图像质量主观及客观指标差异均无统计学意义(P均>0.05).结论 经左或右侧肘正中静脉注射对比剂行CCTA所获图像质量相当.

目的:探索冠脉追踪冻结技术(SSF)对不同扫描模式的冠脉CT血管成像(CCTA)图像质量的改善作用.方法:回顾性分析134例行CCTA检查患者图像资料,根据扫描所采用序列不同,入组患者分为常规屏气组(n=73)和自由呼吸组(n=61).各组数据均行标准算法和SSF运动校正算法重建图像,并分别进行图像质量评价.结果:常规屏气组与自由呼吸组内SSF算法图像的图像质量均优于标准算法图像,但2组间SSF算法图像的平均图像质量得分、图像噪声、冠脉血管密度值、信噪比及对比噪声比之间差异均无统计学意义(均P＞0.05).自由呼吸组SSF算法与标准算法的图像质量评分差值(1.00±2.00)显著大于常规屏气组差异有统计学意义(0.25±1.25,P＜0.05),即与常规屏气组相比,SSF算法在自由呼吸组中对图像质量改善更显著.结论:SSF算法有助于改善CCTA图像质量,尤其是对自由呼吸扫描模式的CCTA图像.

Purpose: To quantitatively identify abnormal lung motion in chronic obstructive pulmonary disease (COPD) using strain analysis, and further clarify the potential differences of deformation in COPD with different severity of airflow limitation. Materials and Methods: Totally, 53 patients at high-risk for COPD were enrolled in this study. All CT examinations were performed on a 320-row MDCT scanner, and strain measurement based on dynamic-ventilation CT data was performed with a computational fluid dynamics analysis software (Micro Vec V3.6.2). The strain-related parameters derived from the whole expiration phase (PSmax-all, PSmean-all, Speed(max-all)), the first 2s of expiration phase (PSmax2s, PSmean2s, Speed(max2s)) were divided respectively by the changes in lung volume to adjust for the degree of expiration. Spearman rank correlation analysis was used to evaluate associations between the strain-related parameters and various spirometric parameters. Comparisons of the strain-related parameters between COPD and non-COPD patients, between GOLD I (mild airflow restriction) and GOLD II-IV (moderate to severe airflow restriction) were made using the Mann-Whitney U-test. Receiver-operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance of the strain-related parameters for COPD. P <0.05 was considered statistically significant. Results: Strain-related parameters demonstrated positive correlations with spirometric parameters (rho=0.275 similar to 0.687,P<0.05), suggesting that heterogeneity in lung motion was related to abnormal spirometric results. Strain-related parameters can quantitatively distinguish COPD from non-COPD patients with moderate diagnostic significance with the AUC values ranged from 0.821 to 0.894. Furthermore, parameters of the whole expiration phase (PSmax-all, Speed(max-all)) demonstrated significant differences (P=0.005, P=0.04) between COPD patients with mild and moderate to severe airflow limitation. Conclusion: Strain-related parameters derived from dynamic-ventilation CT data covering the whole lung associated with lung function changes in COPD, reflecting the severity of airflow limitation in some degree, even though its utility in severe COPD patients remains to be investigated.

Purpose: To quantitatively identify abnormal lung motion in chronic obstructive pulmonary disease (COPD) using strain analysis, and further clarify the potential differences of deformation in COPD with different severity of airflow limitation. Materials and Methods: Totally, 53 patients at high-risk for COPD were enrolled in this study. All CT examinations were performed on a 320-row MDCT scanner, and strain measurement based on dynamic-ventilation CT data was performed with a computational fluid dynamics analysis software (Micro Vec V3.6.2). The strain-related parameters derived from the whole expiration phase (PSmax-all, PSmean-all, Speedmax-all), the first 2s of expiration phase (PSmax2s, PSmean2s, Speedmax2s) were divided respectively by the changes in lung volume to adjust for the degree of expiration. Spearman rank correlation analysis was used to evaluate associations between the strain-related parameters and various spirometric parameters. Comparisons of the strain-related parameters between COPD and nonCOPD patients, between GOLD I (mild airflow restriction) and GOLD II–IV (moderate to severe airflow restriction) were made using the Mann–Whitney U-test. Receiver-operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance of the strain-related parameters for COPD. P <0.05 was considered statistically significant. Results: Strain-related parameters demonstrated positive correlations with spirometric parameters (ρ=0.275~0.687, P<0.05), suggesting that heterogeneity in lung motion was related to abnormal spirometric results. Strain-related parameters can quantitatively distinguish COPD from non-COPD patients with moderate diagnostic significance with the AUC values ranged from 0.821 to 0.894. Furthermore, parameters of the whole expiration phase (PSmax-all, Speedmax-all) demonstrated significant differences (P=0.005; P=0.04) between COPD patients with mild and moderate to severe airflow limitation. Conclusion: Strain-related parameters derived from dynamic-ventilation CT data covering the whole lung associated with lung function changes in COPD, reflecting the severity of airflow limitation in some degree, even though its utility in severe COPD patients remains to be investigated.

目的:比较2种不同碘浓度对比剂对冠脉CT血管造影(CTA)图像质量的影响.方法:回顾性分析门诊行冠脉CTA检查、体重＜90kg且身体质量指数＜30kg/m2、未行冠脉支架植入术或搭桥术的患者,共97例.男45例、女52例;平均55.8±11.0岁.根据所用对比剂不同(碘佛醇350mg I/ml或碘普罗胺370mg I/ml)分为2组.2组均采用对比剂和生理盐水双筒注射,流速5ml/s,对比剂总量75ml,生理盐水30ml.由2名放射科医师采用盲法对冠脉CTA图像质量进行评分(1～4分)及测量分析.比较2组间图像质量的差异.结果:2组间冠脉血管密度值不存在统计学差异(P＞0.05),但采用1.8g I/s碘流率(IDR)校正后,碘佛醇组显著高于碘普罗胺组(P＜0.05).2组的平均图像质量得分、图像噪声、信噪比、对比噪声比均不存在统计学差异(均P＞0.05).结论:在相同对比剂注射方案下,不同浓度含碘对比剂(350mg I/ml vs.370mg I/ml)的冠脉CTA图像质量无明显的统计学差异,进行IDR校正后,相对低浓度对比剂组的血管密度值更高.

目的 探讨自适应统计迭代重组(ASIR)不同水平设定对于肺功能定量CT参数测定影响.方法 搜集2016年2月至2016年3月28例吸烟患者,男20例,女8例;年龄(58.43±17.26)岁.高分辨率CT检查数据,间隔10％设定ASIR进行图像重组,利用机器自带肺功能软件进行定量分析,观察10％～90％ ASIR水平肺内低密度区(＜-950 HU)比例以及全肺体积变化.不同ASIR水平肺功能定量参数[肺内低密度区占比(LAA％)、全肺体积(ILV)]间采用Friedman检验或单因素重复测量方差分析方法.P＜0.05为差异具有统计学意义.结果 ASIR水平对于LAA％结果具有明显影响,随着ASIR数值提高,LAA％呈下降趋势(x2=29.426,P＜0.001).不同ASIR水平之间TLV不存在明显统计学差异(F=1.046,P=0.325).结论 不同ASIR水平对于肺功能定量CT参数LAA％具有明显影响,在利用CT对小气道病变进行定量分析,或者不同研究中心数据进行对比时,需考虑到ASIR水平可能带来的影响.

双能CT (dual-energy computed tomography,DECT)也称“多光谱CT”,是基于不同能量设置下数据采集的成像技术.X射线光子在不同能量设置下与物质进行相互作用从而产生不同衰减值,通过分析X线光子与物质的相关作用可以区分和量化组织成分[1].DECT数据能够重建生成具有较高对比噪声比的虚拟单色能量图像,回顾性获取虚拟未增强图像,组织成分图(如碘图)并减轻金属伪影,改善图像对比度[1,2].随着技术和设备更新,DECT在肠道疾病中的应用日益广泛,本文主要就DECT在肠道病变中研究应用现状做一综述.

Abstract Background To investigate whether MRI findings, including texture analysis, can differentiate KRAS mutation status in rectal cancer. Methods Totally, 158 patients with pathologically proved rectal cancers and preoperative pelvic MRI examinations were enrolled. Patients were stratified into two groups: KRAS wild-type group (KRASwt group) and KRAS mutation group (KRASmt group) according to genomic DNA extraction analysis. MRI findings of rectal cancers (including texture features) and relevant clinical characteristics were statistically evaluated to identify the differences between the two groups. The independent samples t test or Mann-Whitney U test were used for continuous variables. The differences of the remaining categorical polytomous variables were analyzed using the Chi-square test or Fisher exact test. A receiver operating characteristic (ROC) curve analysis was performed to evaluate the discriminatory power of MRI features. The area under the ROC curve (AUC) and the optimal cut-off values were calculated using histopathology diagnosis as a reference; meanwhile, sensitivity and specificity were determined. Results Mean values of six texture parameters (Mean, Variance, Skewness, Entropy, gray-level nonuniformity, run-length nonuniformity) were significantly higher in KRASmt group compared to KRASwt group (p < 0.0001, respectively). The AUC values of texture features ranged from 0.703~0.813. In addition, higher T stage and lower ADC values were observed in the KRASmt group compared to KRASwt group (t = 7.086, p = 0.029; t = − 2.708, p = 0.008). Conclusion The MRI findings of rectal cancer, especially texture features, showed an encouraging value for identifying KRAS status.