三代双源CT对复杂心率病人一站式心脑血管成像的研究

目的探讨使用第三代双源CT(FORCE CT)对复杂心率病人行冠状动脉和头颈部动脉联合扫描的可行性。方法前瞻性收集我院行冠状动脉CT血管造影(CTA)和头颈部动脉CTA检查的复杂心率病人104例,随机分为试验组(52例)与对照组(52例)。试验组采用第三代双源CT前瞻性心电门控大螺距模式进行冠状动脉和头颈部动脉联合CTA检查;对照组采用第三代双源CT分别进行冠状动脉CTA和头颈部动脉CTA检查,其中冠状动脉CTA检查采用前瞻性心电门控轴扫模式,头颈部动脉CTA采用双能量扫描模式。评估并比较两组图像质量、辐射剂量和对比剂剂量。结果两组冠状动脉和头颈部动脉图像质量客观评价指标CNR、SNR比较,差异均无统计学意义(P0.05);图像质量的主观评价一致性Kappa值为0.823,且试验组与对照组图像质量主观评分比较,差异无统计学意义(P0.05)。试验组有效辐射剂量明显低于对照组,差异有统计学意义(P0.05)。结论使用第三代双源CT前瞻性心电门控大螺距模式对复杂心率病人行冠状动脉与头颈部血管联合扫描图像质量好,辐射剂量低,对比剂用量低,可以满足临床诊断需要。     

不同心率对320排CT冠状动脉成像质量和辐射剂量的影响

目的:观察不同心率对320排冠状动脉CT血管造影检查(CTA)图像质量及辐射剂量的影响。方法:收集行CTA检查的161例患者,静息心率均≥70次/min,检查前口服25～50 mg酒石酸美托洛尔。根据扫描时心率分为3组,A组心率65次/min(n=71);B组心率65～75次/min(n=54);C组心率75次/min(n=36)。比较各组的CTA图像质量评分、辐射剂量(ED)。结果:A组图像质量评分高于B、C组,差异有统计学意义(P0.05)。A、B组ED均低于C组,3组间ED比较差异均有统计学意义(t=-6.103,-7.589,-2.764,P均0.05)。心率与有效辐射剂量呈正相关(r=0.587,P0.05)。结论:在行320排CTA检查前控制心率,可有效提高图像质量并减少辐射剂量。     

自由呼吸肺静脉CT造影容积扫描技术的可行性研究

目的:探讨自由呼吸肺静脉容积CT扫描的可行性研究。方法:选择行肺静脉CT造影者(PCTV)患者140例,随机分为A组常规屏气扫描组70例和B组自由呼吸扫描组70例,比较两组的图像质量、辐射剂量和对比剂用量。结果:两组测量区平均CT值、信噪比之间差异无统计学意义,主观图像质量评分差异无统计学意义(P=1.152);辐射剂量(P=0.482)和对比剂用量(P=0.585)比较,差异无统计学意义。结论:采用宽体探测器CT前瞻性心电门控容积扫描模式,在自由呼吸状态下PCTV具有可行性。     

冠状动脉追踪冻结技术对冠状动脉多层螺旋CT血管成像质量的优化研究

目的探讨冠状动脉追踪冻结技术(snapshot freeze,SSF)对冠状动脉多层螺旋CT血管成像图像质量的优化价值。方法回顾性分析北京军区总医院2013年3月~5月期间85例未服用控制心率药物的冠状动脉CTA检查患者影像学资料,应用SSF技术前后CT图像质量差异情况比较。患者按心率是否大于65次/min分为AB两组,其中A组26例,心率≤65次/min;B组59例,心率65次/min。应用冠状动脉追踪冻结技术对冠状动脉图像进行处理,测量应用SSF技术前后,左冠状动脉前降支、左回旋支及右冠状动脉的血管轴截面、运动伪影及邻近脂肪的SD值,计算运动伪影指数(MAI)数值;并采用盲法由两名高年资主治医师对图像质量进行五分制评分,对评分结果进行比较及量化分析。结果 A组患者平均心率(58.5±5.69)次/min;MAI:使用SSF技术为(12.65±5.96),低于未使用SSF技术(None-SSF)(24.10±8.62),差异有统计学意义(P0.05);主观图像评分:使用SSF技术为SSF(4.15±0.45),高于None-SSF(3.00±1.04),差异有统计学意义(P0.05)。B组患者平均心率(77.73±9.67)次/min;MAI:使用SSF技术为(18.09±9.00),低于None-SSF(66.99±17.49),差异有显著统计学意义(P0.01);主观图像评分使用SSF技术为(3.82±0.78),高于None-SSF(1.96±0.67),差异有显著统计学意义(P0.01)。A组患者应用SSF处理后MAI平均下降48%,B组患者应用SSF处理后MAI平均下降73%,下降幅度明显大于A组。结论冠状动脉追踪冻结技术(SSF)可以提高冠状动脉CTA的图像质量,作用在患者心率超过65次/min时更为明显。     

心率对急性胸痛患者320排容积CT前瞻Wide-volume一站式扫描冠状动脉图像质量的影响研究

目的 探讨心率对急性胸痛患者320排容积CT前瞻Wide-volume一站式扫描冠状动脉图像质量的影响。方法 选取2016年5—11月在河北北方学院附属第一医院就诊的急性胸痛患者60例,均经急诊心电图、超声、常规胸部X线检查及实验室检查仍不能明确病因。60例患者均行320排容积CT前瞻Wide-volume一站式扫描,并根据检查过程中即时心率分为40次/min心率≤65次/min者28例(A组)、65次/min心率75次/min者15例(B组)及75次/min≤心率90次/min者17例(C组);所得图像传至Vitrea图像处理工作站进行图像后处理及主、客观评价。结果 3组患者冠状动脉图像优良率比较,差异无统计学意义(P0.05)。3组患者评价者1、评价者2对冠状动脉图像质量的评分及冠状动脉图像质量最终评分比较,差异无统计学意义(P0.05)。2名评价者冠状动脉图像质量评分的一致性较好(Kappa=0.775,P0.001)。3组患者主动脉根部(AA)和冠状动脉各节段CT值均250 HU,符合诊断要求;3组患者AA和冠状动脉各节段CT值和信噪比(SNR)比较,差异均无统计学意义(P0.05)。3组患者AA、右冠状动脉近段(RCAP)、右冠状动脉中段(RCAm)、右冠状动脉远段(RCAd)、后降支(PDA)、左主干(LM)、左前降支近段(LADP)、左前降支中段(LADm)、左前降支远段(LADd)、左回旋支近段(LCXP)及左回旋支第一钝缘支(LCX-OM1)对比噪声比(CNR)比较,差异无统计学意义(P0.05),而A组患者左前降支第一对角支(LAD-D1)、左回旋支中段(LCXm)及左回旋支远段(LCXd)CNR均高于B组和C组(P0.05)。结论 320排容积CT前瞻Wide-volume一站式扫描冠状动脉图像能满足急性胸痛患者的临床诊断要求,但检查时心率65次/min会对冠状动脉图像质量产生一定影响。     

原发性高血压患者主动脉夹层钙化特点分析

目的分析原发性高血压患者主动脉夹层(AD)的血管钙化(VC)特点。方法选择2010年1月至2015年12月于中山大学孙逸仙纪念医院住院的原发性高血压并经过主动脉计算机断层扫描血管造影(CTA)确诊为AD的30例患者为AD组,原发性高血压且主动脉CTA提示无主动脉病变者30例为对照组。通过CTA和Agatston评分系统分析2组人群以及不同Stanford类型AD患者之主动脉钙化特点。结果与对照组比较,AD组降主动脉VC发生率升高(P0.05),主动脉弓VC发生率下降(P0.05)。2组Agatston评分及不同程度VC发生率的差异无统计学意义(均P0.05)。AD组患者分为Stanford A型及Stanford B型2个亚组。2个亚组的临床资料、主动脉及不同部位VC发生率差异无统计学意义(均P0.05)。多因素Logistic回归分析显示,与AD病变相关的因素有:低密度脂蛋白胆固醇(OR=3.397,95%CI 1.234～9.354,P=0.018)、不规律服用降压药(OR=20.417,95%CI2.326～179.233,P=0.006)、主动脉弓VC发生率(OR=0.027,95%CI 0.002～0.357,P=0.006)及降主动脉VC发生率(OR=35.606,95%CI 2.475～512.27,P=0.009)。结论原发性高血压患者主动脉不同部位钙化特点不同可能是高血压促进AD病变的重要环节。     

急性心肌梗死恢复期患者平板运动试验Q-T间期离散度的价值研究

目的 探讨急性心肌梗死恢复期患者运动试验后Q-T间期离散度（Q-Td）的变化.方法 观察51例急性心肌梗死恢复期患者（观察组）平板运动试验的Q-Td的变化,并观察运动后出现严重室性心律失常、胸痛、血压下降与Q-Td变化的关系.结果 患者峰心率时Q-Td（64.3±20.5ms）较运动前（51.2±23.5ms）增大,差异有显著统计学意义（P＜0.01）.运动中出现严重室性心律失常或明显胸痛、血压下降者15例（A亚组）与36例未出现者（B亚组）比较,运动前Q-Td差异无统计学意义（59.1±17.5ms和16.3±19.2ms,P ＞0.05）,峰心率时A亚组Q-Td（76.8±15.5ms）较B亚组（60.1±16.1ms）延长,差异有显著统计学意义（P＜0.01）.两亚组Q-Td多壁梗死均比单壁梗死延长,A亚组多壁梗死比B亚组延长,差异均有统计学意义（P ＜0.05）.结论 急性心肌梗死患者运动后Q-Td进一步增大,出现严重室性心律失常的危险性增大.平板运动试验可作为筛选急性心肌梗死高危人群的手段之一.     

SSF技术在高心率和心率波动受检者CCTA中的应用价值

目的探讨SSF技术在改善高心率(心率70次/min)和心率波动受检者冠状动脉成像质量中的临床应用价值。方法选取66例高心率和心率波动受检者进行冠脉CT血管成像扫描后,分别得到A、B两组图像,其中A组图像采用标准重建,B组图像采用SSF重建,并将检查结果进行对比,分析两组之间冠状动脉图像质量差异。结果除了左主干显示无明显差异外,其余冠状动脉节段B组图像质量均优于A组(P0.05),右冠状动脉S2、S3段及回旋支S10段图像质量明显改善;随着心率增加,A、B两组图像质量均有下降,二者之间无统计学意义(P0.05)。结论 SSF技术可以改善高心率及心率不稳病人的冠状动脉成像质量,满足临床诊断需求,拓宽了受检者临床检查范围,让冠状动脉CTA检查成为真正意义上的冠状动脉病变首选筛查手段,为冠心病临床诊断提供有价值的影像学信息。     

第二代双源CT Flash Spiral模式高心率冠状动脉成像的图像质量及准确性评价

目的评价第二代双源CT大螺距前瞻性螺旋扫描（Flash Spiral）高心率冠脉成像的图像质量、准确性及有效射线剂量。方法前瞻性入选心率〉65次／min的连续性患者268例,随机分为两组。A组134例,采用Flash Spiral模式扫描,采集图像时间为RR间期20％-30％;B组134例,采用回顾性心电门控扫描模式（Spiral）扫描。30d内A组有47例行冠状动脉造影术（CCA）检查（A1组）,B组中有45例行CCA检查（B1组）。比较两组患者一般情况、图像质量评分、图像噪声、对比信噪比（CNR）和有效射线剂量。以CCA结果为金标准,分别计算A1、B1两组FlashDSCT显示冠脉病变的敏感性、特异性、准确率、阳性预测值和阴性预测值。结果①两组患者一般情况比较差异无统计学意义。②两组不可诊断节段基于血管节段评价分别为1．52％和1．74％,基于患者评价分别为7．5％和6．7％,差异均无统计学意义（P=0．345,P=0．812）。两组图像质量评分均数分别为1．064±0．306和1．084±0．327,差异无统计学意义（P=0．063）。A组平均图像噪声19±27（21．4±4．5）HU,CNR6．4-25．3（12．1±4．2）：B组分别为19±28（20．9±4.3）HU和7．1-28．2（13．8±5．1）,两组比较差异无统计学意义。③心率变异性：A组图像质量评分3分的病例平均心率变异性明显小于B组。④与CCA比较,两组患者评价冠状动脉狭窄的敏感性、特异性差异均无统计学意义。⑤射线剂量：A组平均有效射线剂量显著低于B组[（1．04±0．16）mSv比（7．05±1．05）mSv,P=0．001]。结论高心率患者（心率〉65次／min）采用Flash双源CT大螺距前瞻性心电门控螺旋扫描在RR间期20％±30％成像,图像质量、准确性与回顾性心电门控扫描接近,而有效射线剂量显著减低。心率变异性对高心率患者FlashSpiral模式扫描图像质量的影响较大。     

自动管电压选择技术在双源CT大螺距心脑一体化血管成像中的应用价值

目的探讨第三代双源CT大螺距心脑一体化血管成像中使用自动管电压选择技术在优化图像质量及降低辐射剂量中的作用。方法选择2019年10月～2020年11月首都医学大学宣武医院神经内科住院行冠状动脉及头颈动脉一体化CT扫描的老年患者100例,随机分为自动管电压组50例,固定管电压组50例。比较2组的一般临床资料、辐射剂量,并对图像质量进行主观及客观评价。结果自动管电压组实际管电流明显高于固定管电压组(P0.01)。自动管电压组剂量长度乘积及有效剂量较固定管电压组明显减低[(121.84±37.17)mGy·cm vs(175.93±18.26)mGy·cm,P0.01;(1.29±0.85)mSv vs(1.89±0.58)mSv,P0.01]。2组冠状动脉主观评分比较,无统计学差异(P0.05)。自动管电压组头颈动脉主观评分明显高于固定管电压组[(3.45±0.66)分vs(3.05±0.72)分,P0.05]。2组各部位图像噪声、信噪比及对比噪声比比较,差异无统计学意义(P0.05)。自动管电压组左冠状动脉主干、右冠状动脉主干、颈总动脉、颈内动脉、大脑中动脉及椎动脉CT值明显高于固定管电压组,差异有统计学意义(P0.01)。结论第三代双源CT大螺距心脑一体化血管成像中使用自动管电压技术可明显降低辐射剂量,并能提供良好的图像质量,值得临床推广应用。     

Indirect CT venography following CT pulmonary angiography: spectrum of CT findings

SUMMARY: Pulmonary embolism (PE) and deep venous thrombosis (DVT) represent two manifestations of the same syndrome, venous thromboembolism. Contrast-enhanced computed tomography (CT) angiography is a practical, efficient alternative to conventional imaging for PE. Following the pulmonary examination, the inferior vena cava (IVC) and the iliac, femoral, and popliteal veins can be studied with CT without additional intravenous contrast administration. Indirect CT venography (CTV) after CT pulmonary angiography (CTPA) simplifies and shortens venous thromboembolism work-up. Initial studies indicate that CTV is comparable to ultrasound in the evaluation of femoral/popliteal DVT. CTV has the advantage of evaluating the iliac veins and inferior vena cava, vessels poorly seen on sonography and venography. Combining CTV with CTPA increases confidence in withholding treatment when results for both the pulmonary arteries and leg veins are negative and increases the diagnosis of venous thromboembolism by 25% over CTPA alone. This pictorial essay will review the normal venous anatomy, CTV technique, and the findings of acute and chronic DVT. Interpretive pitfalls and alternative diagnoses are also reviewed.     

Virtual CT colonoscopy and virtual CT barium enema using multidetector-row CT]

CT colonography is a promising technique that provides both multiplanar and endoluminal perspective of the air-filled, distended, cleaned colon. "Virtual colonoscopy" refers to computer-simulated 3D endoscopic visualization of the colonic mucosal surface. Unlike barium enema and conventional colonoscopy, CT colonography can give cross- sectional and endoluminal images of the colon and enables to image extracolic abnormality. CT colonography offers potential advantages over colonoscopy in that it causes little discomfort to the patient, and does not need sedation. It is more accurate in spatial location of lesions and creates no complication. To date, most studies assessing CT colonography have focused in technical development, less aggressive bowel preparation, and computer-aided diagnosis of polyp detection. In the future, CT colonography would be a diagnostic and screening tool for the colorectal polyp and cancer.     

Controlling intracoronary CT number for coronary CT angiography

BackgroundControlling intracoronary computed tomography (CT) number for coronary CT angiography (CCTA) has been difficult.ObjectiveThe study assessed whether intracoronary CT number of CCTA could be estimated.MethodsOne hundred twenty six patients were randomly assigned to either CCTA with 30 mL of contrast media (CM) following 5 mL of CM at timing bolus or CCTA with 50 mL of CM following 10 mL of CM at timing bolus. The relationships between intracoronary CT number and patients’ characteristics and peak time and peak CT number at timing bolus in patients who showed valid time–density curve were analyzed in both groups. Then, the multiple regression equation best described was made. The prediction system was validated by 112 patients randomly targeted between 250 HU and 430 HU of CT number.ResultsIn group 5/30, intracoronary CT number was positively correlated with peak CT number at timing bolus (correlation coefficient, 1.42, p < 0.001), negatively correlated with body surface area (?109.19, p < 0.001) and peak time (?6.93, p < 0.001). Whereas, intracoronary CT number was positively correlated with only peak CT number at timing bolus (1.33, p < 0.001) in group 10/50. Then, CT number-controlling system using the simple equation best described CT number was established for CCTA following 5 mL of CM at timing bolus. Of 112 patients, there was good correlation between target CT number and measured CT number (r = 0.85, p < 0.0001) in 96 patients (85.7%), having valid time–density curve at timing bolus.ConclusionsControlling CT number may be enabled by CT number-controlling system following 5 mL of CM at timing bolus.     

Cardiac CT and CT coronary angiography: technology and application

Multislice computed tomography (MSCT) is an additional potential tool for the assessment of coronary artery disease. It can provide information about stenoses in coronary arteries and coronary artery bypass grafts, ventricular size and function, cardiac structure and masses, pulmonary vein anatomy, myocardial perfusion and coronary artery plaque. In this review the recent developments in CT technology that have made cardiac imaging possible are examined and the benefits of the latest 64-slice and dual-source CT scanners explained. Information on how to perform cardiac CT and evidence for its various clinical applications are given. Problems and limitations of cardiac CT and the radiation dose are discussed. Future developments and the likely impact of this rapidly evolving technique on clinical cardiology are considered.     

CT enterography: state-of-the-art CT technique for small bowel imaging

Multi-detector computed tomography has become a first-line imaging modality for the evaluation of small bowel disease. Its high speed and resolution ensure excellent imaging of the small bowel with simultaneous evaluation of the lumen and wall, adjoining mesentery, and extraluminal structures in the abdominal cavity. Optimal luminal distension is an important prerequisite. Computed tomography enterography (CTE) is a dedicated adaptation for the study of the small bowel. This review discusses CTE with emphasis on procedural technique and image interpretation.