应用高分辨率自由呼吸导航全心磁共振成像技术无创性评价冠状动脉舒张性能的初步研究

目的 分析自由呼吸导航全心MR冠状成像技术进行舌下含服硝酸甘油试验评价冠状血管舒张性能的可行性.方法 对18例志愿者,使用自由呼吸导航全心MR冠状动脉成像序列,完成舌下含服硝酸甘油前以及含服后的扫描,分别测量2次扫描的冠状动脉管腔截面积,测量节段包括左主干、左前降支近段、左回旋支近段及右冠状动脉近段,计算冠状动脉血管扩张率,并进行统计分析.结果 18例志愿者均完成使用硝酸甘油前后的扫描,无明显不适及过敏反应.全心自由呼吸导航MR冠状动脉成像能有效显示硝酸甘油的冠状动脉舒张效应,冠状动脉主要分支均可见扩张,硝酸甘油服用前/后的截面积测量如下:右冠状动脉近段为(11.7±4.4) mm2/(16.5±6.1) mm2 (P<0.05),左主干为(16.6±4.3) mm2/(23.2±7.2) mm2 (P<0.05),左前降支近段为(12.9±4.3) mm2/(17.8±6.7) mm2 (P<0.05),左回旋支近段为(10.6±3.0) mm2/(14.3±4.8) mm2 (P<0.05).服用硝酸甘油后冠状动脉血管的总体扩张率为(37.24±15.33)%.结论 自由呼吸导航全心MR冠状动脉成像技术能显示硝酸甘油诱导的冠状动脉血管扩张反应,有望成为一种无创性评价冠状动脉舒张能力的方法.     

CTA诊断左冠状动脉右心房瘘并动脉瘤一例

病例资料 患者,男,38岁.因活动后喘气伴胸闷1月余入院.患者活动量较大时即感症状明显,休息后可缓解.既往无特殊病史.体检:颈静脉无怒张,心率80次/分,律齐,心尖区可闻及Ⅱ/6级收缩期杂音.彩超:左冠状动脉右心房瘘,左冠状动脉回旋支瘤样扩张,左心腔扩大,二尖瓣轻度返流.运动平板实验(一).选择性冠状动脉造影:右冠及左冠前降支无明显异常,回旋支开口异常,血管纡曲,血管远端未见瘘管.64排CTA:左冠状动脉窦扩张,冠状动脉左主干明显扩张,直径约2.0 cm,管壁可见斑块状钙化,左前降支及左回旋支由此发出,走形及管径未见明显异常;可见一增粗的异常分支纡曲走形沿左心房顶部延伸至房间隔上部,开口于右心房,其近右心房段局部呈瘤样扩张,直径约2.5cm,右心房扩大.     

16层螺旋CT冠状动脉血管成像技术临床应用

目的:探讨16层螺旋CT冠状动脉成像技术临床应用价值。方法:对45例临床诊断或可疑冠心病的住院患者行16层螺旋CT冠状动脉回顾性心电门控平扫及增强扫描。将增强扫描图像传送到Wizard图像工作站进行最大密度投影(MIP)、多平面重组(MPR)、曲面重组(CPR)、容积再现技术(VRT)及平带多平面重组(RMPR)。并将VRT及MIP重组像为参照,用平扫图像对冠状动脉各支段进行钙化积分。结果:左冠状动脉主干(LM)、左前降支近中段(LAD1、LAD2)、第一对角支(D1)、左回旋支(LCX)及右冠状动脉近段(RCA1)显示均45例(100%),左前降支远段(LAD3)23例(51%),第二对角支(D2)30例(67%),第三对角支(D3)24例(53%),第一左缘支(M1)36例(80%),第二缘支(M2)28例(62%),右冠状动脉中段(RCA2)41例(91%),右冠状动脉远段(RCA3)43例(96%)及后降支(PDA)34例(76%)。左冠状动脉主干钙化12例(27%),左前降支近中段钙化有29例(64%),左回旋支钙化例数22例(49%),右冠状动脉近中段钙化有24例(53%)。结论:16层螺旋CT可对冠状动脉进行钙化积分并准确显影,是冠状动脉粥样硬化疾病筛选和诊断的首选方法。     

高流速稀释对比剂在低管电压冠状动脉成像中的可行性研究

目的探讨高流速稀释对比剂在低管电压冠状动脉成像中的可行性及对图像质量的影响。方法收集120例疑似冠心病患者行冠状动脉CTA检查,按照随机数字表法等分为A、B、C三组各40例。A组以4.8ml/s直接注射碘普罗胺(300mg I/ml),之后按相同速率追加注射生理盐水36ml,B、C两组以6ml/s注射稀释对比剂,其浓度为使用双流技术按对比剂与生理盐水8:2实时配比为240mg/ml,两组按相同速率追加注射生理盐水45ml。A、B、C三组对比剂用量分别为0.8ml/kg、1ml/kg、0.8ml/kg,三组所得扫描数据均使用迭代算法(AIDR 3D)重建图像,扫描管电压设置分别为100k V、100k V、80k V。比较三组之间升主动脉、降主动脉、左冠状动脉主干、左前降支近段、左回旋支近段及右冠状动脉近段平均强化CT值(SI)、噪声(SD)、对比噪声比(CNR)、信噪比(SNR)有效辐射剂量(E)及冠状动脉图像质量评分。结果三组年龄、心率、管电流、体质指数(BMI)、体重、身高均无统计学差异(P0.017),A组与B、C两组注射压力有统计学差异(P0.017),B组与A、C两组对比剂注射用量有统计学差异(P0.017),C组与A、B两组间注射时间、总碘含量、辐射剂量(ED)有统计学差异(P0.017)。三组间总节段质量得分及各大段平均质量得分均无统计学差异(P0.05)。A、C两组升主动脉、右冠状动脉近段血管强化值及右冠状动脉、左冠状动脉主干、左前降支近段噪声有统计学差异(P0.017),B、C两组升主动脉血管强化值、右冠状动脉及左回旋支近段噪声有统计学差异(P0.017)。三组之间胸主动脉及各冠状动脉血管近段SNR、CNR无统计学意义(P0.05)。结论使用6ml/s的高流速240mg/ml稀释对比剂在低管电压冠状动脉CTA中可以满足诊断需求并且不降低图像质量。     

GRAPPA技术在呼吸导航磁共振冠脉成像中的应用

目的:评价GRAPPA技术在呼吸导航磁共振冠脉成像中的应用价值.方法:时19例志愿者使用和不使用GRAPPA技术行右冠脉靶容积扫描,并使用GRAPPA技术行全心扫描.经后处理得到冠脉图像,从扫描时间、信噪比、对比噪声比、图像质量方面评价应用GRAPPA前后的图像;评价冠脉主要分支的显示情况.结果:GRAPPA技术应用前的扫描时间为(7.67±1.24)min、信蹂比为35.89±4.64、对比噪声比为20.35±4.27,应用后分别为(4.65±1.25)min、29.73±4.18、16.42±3.77,三者差异有统计学意义;图像评分差别无统计学意义.靶容积扫描和全心扫描对右冠脉近中段的显示率分别为94.7%和93.3%,对右冠脉远段显示率分别为78.9%和86.7%,全心扫描对左主干及前降支、回旋支近中段显示率为93.3%,前降支及左回旋支远段为86.7%和80.0%.结论:GRAPPA技术可缩短呼吸导航磁共振冠脉成像(41±13)%的扫描时间(加速因子为2),获得良好的冠状动脉图像,应用GRAPPA技术可完成全心扫描,与靶容积扫描相比,具有更好的应用前景.     

稀释对比剂注射法在64层螺旋CT冠状动脉成像中的应用研究

目的比较不同对比剂方案对冠状动脉成像的影响。方法 60例临床疑诊冠心病患者在行回顾性心电门控64-层螺旋CT冠状动脉造影检查中,根据不同对比剂方案随机分为以下3组:A组(20例)先注射对比剂,后注射生理盐水;B组(20例)先注射对比剂,后注射对比剂与盐水以3∶7比例配制的稀释液;C组(20例)先注射对比剂,后注射对比剂与盐水以1∶1比例配制的稀释液。分别测量所有患者冠状动脉左主干、左前降支、左回旋支及右冠状动脉的CT值。对获自显示冠状动脉、右心室均匀性及左心室壁的数据,利用SPSS13.0软件进行统计学分析与比较。结果在冠状动脉左主干、左前降支、左回旋支测得的CT值以及右心室均匀性显示,各组间均无显著性差异(P>0.05),然而,左心室壁的显示在A、B组之间或A、C组之间均有显著性差异(P=0.0001),在B、C组之间亦有显著性差异(P=0.0007)。结论在64层螺旋CT冠状动脉增强扫描中,稀释对比剂方案优于传统的注射方案(A组),以3∶7比例配制的稀释液(B组)为最佳方案。     

64层螺旋CT血管成像对低龄儿童川崎病冠状动脉病变的随访诊断价值

目的 评价64层螺旋CT(MSCT)对低龄儿童川崎病冠状动脉瘤的随访诊断价值和应用可行性.方法 对12例随访中的川崎病冠状动脉瘤患儿(平均年龄5.2岁,随访时间1.1～5.1 年)进行64层MSCT冠状动脉成像,观察冠状动脉病变的程度和冠状动脉瘤的数目、位置、形态和大小,并和同期超声心动图(ECHO)进行比较分析.结果 MSCT共观察到30个冠状动脉瘤,左、右冠状动脉各15个,肿瘤最宽径为20.6 mm,平均(7.5±3.8)mm;最长径为38.0 mm,平均(124±9.1)mm;10个小冠状动脉瘤,7个中等冠状动脉瘤,13个为巨大瘤;14个圆形,16个梭形.累及左冠状动脉主干7个,前降支近段9个,前降支中段4个,回旋支2个;右冠状动脉近段6个,右冠状动脉中.段9个,右冠状动脉远段4个;其中9个肿瘤累及2个节段,1个累及3个节段.发现6处狭窄,5个瘤壁钙化,3个合并血栓.8个较小或位于中远段的冠状动脉瘤ECHO未能发现.结论 64层MSCT能清晰显示冠状动脉瘤和冠状动脉病变程度,可成为低龄川崎病冠状动脉瘤患儿随访和诊断的重要评估方法.     

按患者体重分期注射造影剂方案在64层螺旋CT冠状动脉成像中的应用

目的评价按患者体重设计的分期注射造影剂方案在64层螺旋CT冠状动脉成像(MSCTCA)中的应用,并与传统注射法比较。方法 100例拟接受MSCTCA患者随机分为传统注射组(共50例,先注射造影剂85 mL,后注射生理盐水30 mL)和分期注射组(50例)。分期注射组按患者体重(<60,61～74,>75 kg)又分为3个亚组。3亚组患者均接受3期注射:1期,均注射生理盐水16 mL;2期,分别注射造影剂70,75和80 mL;3期,分别注射造影剂与生理盐水(3∶7)混合物30,30和40 mL。由两名经验丰富的放射医师盲法评价冠状动脉各分支(15节段)显示情况与图像质量,并比较两种注射方案的差异。结果分期注射组中右冠状动脉(RCA)远段、右后降支(RPD)、左前降支(LAD)远段、第一第二对角支(D1、D2)、左回旋支(LCX)远段、左室后支(LVP)及左后降支(LPD)的图像质量明显优于传统注射组(P<0.05),但是两组间RCA近段、RCA中段、左主干(LM)、LAD近段与中段、LCX近段及钝缘支(BE)的图像质量无明显差异(P>0.05)。结论在MSCTCA中,分期注射方案较传统注射法明显提高了冠脉动脉远端分支的强化程度,提供了更好的图像质量,因而能更好地满足临床诊断要求。     

64层螺旋CT冠状动脉粥样硬化斑块稳定性分析

目的探讨64层螺旋CT冠状动脉成像在判别冠心病不同类型间斑块性质方面的价值。方法经冠状动脉造影(CAG)证实明确诊断为冠心病的患者126例,行64层螺旋CT冠状动脉成像,并对主要冠状动脉狭窄节段数、狭窄程度以及斑块性质进行比较。结果本组患者冠状动脉评估节段数368个,其中狭窄节段195个(35.4%)。狭窄<50%共98个节段,狭窄50%～75%共71个节段,狭窄>75%共26个节段(左前降支中段、近段、后降支中段、左回旋支近段),其中完全闭塞2个(右冠状动脉近段以远、左回旋支中段以远)。软斑块46个(27.3%),纤维斑块42个(31.5%),混合斑块78个(29.5%),钙化斑块93个(12.6%)。对应斑块测量的CT值分别为软斑块(17±26)HU,纤维斑块(97±35)HU,钙化斑块(489±195)HU。结论 64层螺旋CT冠状动脉成像有助于显示斑块性质。     

优化扫描范围对CT冠状动脉成像辐射剂量和图像质量的影响

目的 初步探讨优化扫描范围(FOV)对冠状动脉CT成像(CTA)辐射剂量和图像质量的影响.方法 选取100例临床疑似冠心病的患者进行冠状动脉CTA检查,随机分成A、B两组,每组各50例.A组FOV为气管分叉处至心脏下缘1 cm;B组FOV根据平扫图像确定,即冠状动脉树上缘1 cm至心尖部心包即将消失的层面.记录患者增强扫描的剂量长度乘积(DLP),选择冠状动脉不同节段测量其对比剂增强水平.分析A、B两组的FOV、有效辐射剂量(ED)及图像质量有无统计学差异.结果 两组患者平均年龄、性别、体重指数(BMI)比较均无统计学意义;A组平均FOV、ED分别为(15.31±1.51)cm、(15.10±2.00) mSv,均高于B组的(13.51±1.68)cm、(12.02±1.40)mSv,且差异均有统计学意义(P＜0.05).两组共显示冠状动脉1303个节段,A组669个节段,B组634个节段,两组间比较差异无统计学意义(P＞0.05).右冠状动脉(RCA)近段、左冠状动脉前降支(LAD)近段及左回旋支(LCX)近段CT值水平差异无统计学意义.结论 根据平扫图像优化冠状动脉CTA FOV,既能有效降低辐射剂量,同时又能保证图像质量,为临床诊断冠心病提供参考信息.     

64层螺旋CT冠状动脉成像的心率变化及其对图像质量的影响

目的探讨64层螺旋CT冠状动脉成像的心率变化及心率变化对图像质量的影响。方法回顾性分析138例64层螺旋CT冠状动脉成像资料,记录扫描期间的心率变化,根据不同的心率变化分组。A组心率变化0~4次/min,B组心率变化5~9次/min,C组心率变化10~20次/min,D组心率变化>20次/min。比较不同组间的冠状动脉各节段图像质量差异。结果64层螺旋CT冠状动脉成像心率变化在10次/min以内者占89%,RCA1、RCA3、PDA、LMA、LAD、LCX1及LCX2的图像质量A、B、C组间无显著差异(P>0.05),D组与A、B、C组对比图像质量明显下降(P<0.05);RCA2的A、B、C、D组间对比图像质量有显著差异(P<0.05),呈下降趋势。结论64层螺旋CT冠状动脉成像心率变化幅度小,心率变化>20次/min,才引起冠状动脉成像质量明显下降,RCA2段图像质量易受心率波动的影响。     

Improvement of image quality with beta-blocker premedication on ECG-gated 16-MDCT coronary angiography

OBJECTIVE: The objective of our study was to assess the effect of beta-blockers on image quality of ECG-gated 16-MDCT coronary angiography. MATERIALS AND METHODS: Coronary CT angiography was performed in two groups: group 1, 24 volunteers (mean age, 50 years; mean heart rate, 69 beats per minute [bpm]; range, 47-97 bpm); and group 2, 15 patients with current ischemic heart disease (mean age, 54 years; mean heart rate, 54 bpm; range, 48-69 bpm) who were premedicated with 20-40 mg of oral propranolol 1 hr before the study. CT scans were obtained on a 16-MDCT scanner with a 12 x 0.75 mm collimation and 420-msec rotation using nonionic contrast material (80 mL; injection rate, 4 ml/sec). Images were reconstructed at 30-80% of the cardiac cycle in increments of 5%. Image quality of the following eight coronary segments was assessed by two radiologists in consensus: left main coronary artery; proximal and middle segments of the left anterior descending (LAD) and left circumflex (LCX) coronary arteries; and the proximal, middle, and distal segments of the right coronary artery (RCA). Image quality was assessed, using a 5-point grading scale, as grades 1-5. Images assessed as grade 4 or 5 were considered to be of diagnostically acceptable quality. RESULTS: In group 1, grade 4 or 5 image quality was achieved for visualization of 92% of the left main coronary arteries; 96% of the proximal LAD coronary arteries; 88% of the middle LAD, proximal LCX, and middle LCX coronary arteries; 83% of the proximal RCAs; 58% of the middle RCAs; and 96% of the distal RCAs. In group 2, this level of image quality was achieved in 100% of the left main coronary arteries, proximal and middle LAD arteries, and proximal LCX arteries; 87% of the middle LCX arteries; and 93% of the proximal, middle, and distal RCAs. CONCLUSION: Reduction of heart rates with beta-blocker premedication improves the image quality of CT coronary angiography, especially in terms of the visualization of the right coronary artery.     

Whole-heart steady-state free precession coronary artery magnetic resonance angiography.

Current implementations of coronary artery magnetic resonance angiography (MRA) suffer from limited coverage of the coronary arterial system. Whole-heart coronary MRA was implemented based on a free-breathing steady-state free-precession (SSFP) technique with magnetization preparation. The technique was compared to a similar implementation of conventional, thin-slab coronary MRA in 12 normal volunteers. Three thin-slab volumes were prescribed: 1) a transverse slab, covering the left main (LM) artery and proximal segments of the left anterior ascending (LAD) and left circumflex (LCX) coronary arteries; 2) a double-oblique slab covering the right coronary artery (RCA); and 3) a double-oblique slab covering the proximal and distal segments of the LCX. The whole-heart data set was reformatted in identical orientations. Visible vessel length, vessel sharpness, and vessel diameter were determined and compared separately for each vessel. Whole-heart coronary MRA visualized LM/LAD (11.7 +/- 3.4 cm) and LCX (6.9 +/- 3.6 cm) over a significantly longer distance than the transverse volume (LM/LAD, 6.1 +/- 1.1 cm, P < 0.001; LCX, 4.2 +/- 1.2 cm, P < 0.05). Improvements in visible vessel length for RCA and LCX in the whole-heart approach vs. their respective targeted volumes were not significant. It is concluded that the whole-heart coronary MRA technique improves visible vessel length and facilitates high-quality coronary MRA of the complete coronary artery tree in a single measurement.     

Usefulness of 64-slice MDCT for follow-up of young children with coronary artery aneurysm due to Kawasaki disease: initial experience

To evaluate the initial application and value of 64-slice multidetector computed tomography as an alternative diagnostic modality in the follow-up of young children with coronary artery aneurysm due to Kawasaki disease. Twelve boys (mean age 5.1 years, range 1.8-7.8 years) for follow-up (time range from 1.1 to 5.1 years) of known Kawasaki disease and coronary artery aneurysm underwent 64-slice MDCT ECG-gated coronary angiography. All data were acquired without breath holding. Two pediatric radiologists independently assessed image quality and the diameter of all coronary segments were measured for each patient. The number, position, shape and size of each coronary artery aneurysm were observed and compared with those of ECHO performed previously. A total of 118/156 segments permitted visualization with diagnostic image quality, the CT measurements showed good inter-observer and intra-observer reliability, coefficients were 0.93 and 0.88, respectively. A total of 30 coronary artery aneurysms were identified with measured mean of 7.5+/-3.8 mm in diameter, and of 12.4+/-9.1 mm in longitudinal lengths.10 tumors were small, 8 tumors were medium and 12 tumors were giant aneurysm. The affected segments included LM7/12(58.3%), 9/12(75%) of LAD1, 4/12(33.3%) of LAD2, 2/12(16.7%) of LCX1; 6/12(50%) of RCA1, 9/12(75%) of RCA2 and 4/12(33.3%) of RCA3, including affected two segments in 9 tumors and three segments in 1 tumor. Calcifications were found in 5 aneurysms and 3/5 with thrombosis; six stenotic segments were found. ECHO failed to detect 8 tumors with 2/8 in LAD, 1/8 in LCX and 5/8 in RCA, and those included 4 small aneurysms. The use of 64-slice MDCT angiography proved valuable for monitoring young children with Kawasaki disease. However, further study is necessary to specify the sensitivity and specificity of MDCT in the follow-up.     

256-MSCT对先天性心脏病婴儿心脏成像的冠状动脉检出情况

目的探讨256-MSCT对复杂性先天性心脏病婴儿(1岁内)心脏成像时的冠状动脉检出情况。方法从789例行256-MSCT检查的<1岁的患儿中随机抽取100例,评价冠状动脉节段的成像情况(按10个节段计算),包括检出的节段数目及血管清晰度。结果总节段检出率为51.7%,左主干(LM)及右冠状动脉(RCA)近段检出率分别为96%和99%,左前降支(LAD)、左回旋支(LCX)、RCA各支血管的节段检出率分别为53.33%、33.67%、53.33%。左、右冠状动脉近段血管清晰度评分(4分/3分/2分/1分)分别为LM(62例/22例/12例/4例)和RCA(56例/20例/17例/7例)。患儿平均接受的有效剂量为(0.898±0.282)mSv。结论 256-MSCT对复杂性先天性心脏病婴儿(1岁内)心脏成像时的冠状动脉检出情况较为满意,尤其对左、右冠状动脉近段检出率很高,且血管清晰度明显提高,能够满足临床诊断需求。     

Enhanced sensitivity and specificity of thallium-201 imaging for the detection of regional ischemic coronary disease by combining SPECT with "bull's eye" analysis

Previous studies have indicated that the combination of single photon emission computed tomography (SPECT) and quantitative "bull's eye" analysis (QBA) TI-201 cardiac stress imaging may improve the detection of myocardial ischemia over that achieved with planar (PLN) imaging. This study will evaluate the sensitivity and specificity of SPECT and QBA in the detection of disease in the left anterior descending (LAD), left circumflex (LCX), and right coronary artery. Ninety-nine patients who underwent both TI-201 stress imaging and coronary arteriography were evaluated retrospectively. Of the 99, 62 had PLN imaging and 37 were evaluated with SPECT; 23 of these 37 had QBA. The overall sensitivity and specificity were as follows: PLN, 94% and 50%; SPECT, 90% and 67%; QBA, 100% and 20%; and SPECT with QBA, 92% and 72%, respectively. The regional sensitivity and specificity of PLN for individual coronary arteries were as follows: RCA, 78% and 74%; LAD, 89% and 60%; LCX, 50% and 89%, respectively. For SPECT, the results were: RCA, 86% and 93%; LAD, 85% and 88%; and LCX, 60% and 88%. For QBA alone, the results were: RCA, 100% and 75%; LAD, 88% and 53%; and LCX, 100% and 89%. The results for QBA with SPECT were: RCA, 100% and 94%; LAD, 88% and 80%; and LCX, 67% and 95%. Thus, SPECT interpreted on conjunction with QBA showed higher sensitivity for evaluation of ischemia in the RCA and LCX arteries and higher specificity in the detection of LAD and RCA disease than did PLN TI-201 imaging. Because of the low specificity of QBA (20%), caution is advised in the interpretation of QBA alone without reviewing SPECT images.     

磁共振冠状动脉成像定位方法

目的 摸索磁共振冠状动脉成像(MRCA)的扫描定位方法。方法 89例受检者，用快速平衡稳态成像(FIESTA)序列获得标准四腔心位、左室和右室长轴位的电影图像并确定舒张中期触发延迟时间，在此基础上用脂肪抑制的三维FIESTA序列在呼气末屏气定位扫描冠状动脉右支(RCA)、左主干(LM)、前降支(LAD)和回旋支(LCX)，以美国心脏协会(AHA)推荐的冠状动脉解剖分段法评价定位显示的可重复性。结果 86例受检者能够屏气配合完成检查，适用效率为96．63％；9个位置可以稳定地显示冠状动脉各主支，各位置综合对RCA近段和中段(AHA-18、19段)、LM全长(AHA-1、2)、LAD近段和中段(AHA-3、5、7段)，LCX近段(AHA-10段)的显示可重复性为100％；对LAD、LCX和RCA的远段(AHA-9、14、21段)的显示可重复性分别为94．19％、72．09％、96．51％。结论 MRCA定位方法简单实用，可以稳定显示冠状动脉主要分支的近段和中段，初步具备临床应用的价值。     

屏气三维快速平衡稳态进动序列在磁共振冠状动脉成像中的可靠性研究

目的 :评价屏气三维快速平衡稳态进动 ( 3D FIESTA)序列在冠状动脉磁共振成像 (CMRA)中的可靠性。材料和方法 :67例受检者 ,采用心电触发的三维FIESTA序列 ,呼气末屏气采样 ,在 8个不同层面方向定位显示冠状动脉各主支 ,包括右冠 (RCA)、左主支 (LM)、左前降支 (LAD)和左回旋支 (LCX) ,以 0 -IV级图像质量体系为参照 ,评分II级以上作为可接受标准 ,采用美国心脏协会 (AHA)的冠状动脉分段标准评价其显示的长度和范围。结果 :67例受检者能够屏气配合完成检查的 65例 ,检查适用率为 97.0 % ;对AHA 18、19段 (RCA近段和中段 )、AHA 1、2 (LM)、AHA 3、5、7段 (LAD近段和中段 ) ,AHA 10段 (LCX近段 )的显示可重复性为 10 0 % ;对AHA 9、14、2 1段 (LAD、LCX和RCA的远段 )的显示可重复性分别为 95 .3 8%、72 .3 1%、96.92 %。结论 :此三维FIESTA序列可以稳定显示冠状动脉主要分支的近段和中段 ,初步具备临床应用的价值。     

Correlation of 3D MR coronary angiography with selective coronary angiography: feasibility of the motion-adapted gating technique

The aim of this study was to verify the feasibility of a respiratory motion compensation technique (motion-adapted gating, MAG) for visualization of coronary arteries (CA) by correlation with selective coronary angiography (SCA). Fifteen subjects (11 patients, mean age 61.3 years, age range 41-73 years; and 4 healthy volunteers, mean age 32.3 years, age range 31-35 years) were investigated. A Philips Gyroscan ACS-NT was used, operating at 1.5 T, was combined with the PowerTrak 6000 gradient system. An ECG-triggered, respiratory motion-gated 3D turbo field echo sequence was used. The real-time algorithm utilized the concept of k-space weighting in combination with automatic analysis of respiratory motion. The main CA were investigated. Qualitative analysis was performed by three blinded investigators. Visibility was graded on a five-point scale (0=not visualized, 1=insufficient, 2=sufficient, 3=good, 4=excellent). Segments graded 2-4 were defined as adequately visualized. Sixty-two of 88 assessable CA segments in patient, and 22 of 32 in volunteer group were adequately visualized. Visibility of CA was classified as excellent for proximal RCA (avg. 3.6+/-0.5), good for LM, proximal LAD, proximal LCX, middle RCA and sufficient for middle LAD. Sensitivity, specificity, positive and negative predictive values for coronary MRA in detection of CA stenoses with luminal narrowing >/=50% were 88, 94, 83, and 96%, respectively. Magnetic resonance imaging in combination with MAG has proven to be a promising technique for noninvasive imaging of CA due to good image quality and a patient convenient free-breathing technique.     

正常体质量指数患者低管电压条件下行CT冠状动脉成像的研究

目的 评估正常体质量指数(BMI)患者在80 kV管电压条件下行冠状动脉CT血管成像(CCTA)的图像质量,探讨降低辐射剂量的可行性.方法 将60例在本院疑诊冠状动脉疾病且BMI在18.6~25 kg/m2的患者行CCTA检查,随机分为A、B组,2组均采用Flash spiral螺旋心脏模式扫描.A组(n=30)采用100 kV及滤波反投影重建(FBP)算法,B组(n=30)采用80 kV及自适应迭代重建(IR)算法.测量主动脉根部、右冠状动脉(RCA)、左冠状动脉前降支(LAD)及左冠状动脉回旋支(LCX)CT值及噪声,计算信噪比(SNR)及对比噪声比(CNR).采用3分法对所有图像进行主观质量评分.记录CT剂量指数CTDIovl,并进行有效辐射剂量(ED)计算.结果 A组平均ED为0.8 mSv,B组平均ED为0.41 mSv,2组之间差异有统计学意义.本研究中图像噪声A组(28±6) HU,B组(46±9) HU,差异有统计学意义;升主动脉根部、RCA、LAD、LCX的CT值80 kV下显著升高,差异有统计学意义.RCA-SNR、LAD-SNR、RCA-CNR 2组比较无统计学差异;LCX-SNR、LAD-CNR、LCX-CNR 2组比较有统计学差异.2组之间可用于诊断的冠状动脉节段数无统计学差异.结论 对于正常BMI的患者,采用80 kV管电压行双源Flash spiral CCTA可满足冠状动脉疾病诊断要求,并能够明显降低辐射剂量.