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。     

屏气三维快速平衡稳态进动序列在冠状动脉磁共振成像中的临床应用价值

目的:评价屏气三维快速平衡稳态进动序列在冠状动脉磁共振成像的临床应用价值.材料和方法:12例受检者,采用外周门控屏气三维快速平衡稳态进动序列(3D FIESTA),呼气末屏气扫描.扫描获得图像按照0～Ⅳ级评分标准评价图像质量,评价冠状动脉的显示范围以美国心脏协会(AHA)推荐的解剖分段标准为参照.结果:图像质量Ⅱ级以上占98%.RCA近段和中段(AHA 18、19段)、LCX近段(AHA 10段)、LM全长(AHA 1、2段)及LAD近段和中段(AHA 3、5、7段)的显示率为100%,RCA远段(AHA 21段)、LCX远段(AHA 14段)及LAD远段(AHA 9段)的显示率分别为83.3%、75%、91.6%.结论:屏气三维快速平衡稳态进动序列在冠状动脉磁共振成像中具有一定的临床应用价值.     

磁共振成像显示冠状动脉起源异常1例

患者男,53岁。反复发作心绞痛10余年,静息间期ECG检查未见异常,心肌酶学检查正常,心脏超声检查无形态及运动异常。冠状动脉造影显示左前降支（LAD）狭窄50％左右,左回旋支（LCX）无狭窄征象,右冠状动脉（RCA）未显影。使用ECG触发的屏气三维快速平衡稳态进动序列（FIESTA）进行冠状动脉磁共振成像（MRA）,RCA与左主干（LM）并行起源左冠窦,经过肺动脉主干和升主动脉间期进入右侧房室沟,并可见粗大的圆锥支（PB）发出,RCA近段光滑清晰、中段管壁不规则,考虑狭窄大于50％;LAD中段第一对角支以远部分可见节段性冠状动脉管腔狭窄和管壁增厚改变,与冠状动脉造影显示一致。     

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。     

冠状动脉狭窄的电子束CT诊断

目的：评价电子束CT(EBCT)及其三维血管成像对冠状动脉狭窄诊断的准确性及局限性。方法：37例经EBCT冠状动脉增强扫描和三维重建的患者，均又经常规心血管造影检查(CAG)。由两名不知其它检查结果的放射科医师将冠状动脉左主干(LM)和左前降支(LAD)、左回旋支(LCX)、右冠状动脉(RCA)的近、中段评价后与造影结果逐段对照．并作统计学分析。结果：在CAG结果≥2mm的219个冠状动脉节段中，EBCT可评价的有228(91.6％)个，无法评价的21(8．1％)个，影响因素最主要为广泛钙化遮蔽管腔。EBCT诊断冠状动脉各主干近、中段≥50％狭窄总的敏感性、特异性和阳性预测值、阴性预测值分别为80．1％、91．3％、72．4％、92．5％。其中左主干均为100％．前降支分别为90．4％、94．2％、84．5％和96．1％。结论：EBCT是较好的无创性冠状动脉成像技术，对冠状动脉左主干和前降支近、中段狭窄的评价具有极高的准确性．虽然无法替代CAG，但极具临床应用潜力。局限性是空间分辨率低，价格昂贵。     

呼吸导航3D BTFE与双反转TSE序列对冠状动脉成像质量的评价

目的 比较呼吸导航三维平衡超快场同波(3D balanced turbo field echo,3D BTFE)与双反转快速自旋回波(TSE)冠状动脉磁共振血管成像(CMRA)方面有无差异.资料与方法 对28例分别利用呼吸导航3D BTFE和双反转TSE序列进行CMRA.在图像后处理[最大密度投影(MIP)、最小密度投影(MinIP)]后,对图像进行半定量评价(0～4级),并对评分≥2者进行统计学分析;采用标准的冠状动脉分段方式评价两种不同方法目标血管显示的成功率;对两种不同方法图像信噪比(SNR)、对比噪声比(CNR)和图像质量的评分进行比较.结果 评分≥2者25例.(1)利用VCG触发和呼吸导航技术能较好地抑制心跳和呼吸运动伪影;(2)两种方法可以显示绝大部分目标节段,二者在右冠状动脉(RCA)近中段、左主干(LM)、左前降支(LAD)近中段、左回旋支(LCX)近中段显示率接近,RCA远段的显示率分别为75%和54%;(3)两种方法的RCA、LM、LAD和LCX的显示长度分别为97.38/89.14、15.34/14.19、52.50/35.41和50.92/49.16 mm;(4)两种方法SNR、CNR和质量评分分别为108.86/4.66、67.77/28.01和3.50/2.54;(5)两种方法的单次扫描时间分别为1 min 45 s和2 min 40 s.结论 (1)两种方法的冠状动脉主干的显示率较高(RCA和LCX远段相对较低);(2)两种方法对患者的配合要求不高,均可在自由呼吸的情况下得到冠状动脉影像;(3)双反转TSE序列在冠状动脉目标节段的显示率上与3D BTFE序列接近,但是,其图像质量较后者差,稳定性不佳,在成像时间上也没有优势;(4)3D BTFE序列在冠状动脉目标节段的显示率、图像质量以及成像时间方面具有优势.     

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。     

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。     

3.0 T MR增强冠状动脉造影3PPS分段采集与全心采集的定量对比分析

目的 采用定量的方法评价3T增强冠状动脉磁共振血管成像(Coronary MR Angiography,CMRA)对冠状动脉的显示能力和图像质量.资料与方法 10例临床疑为冠心病的患者接受了3 T增强CMRA检查,采集技术包括3点定位(3PPS)分段采集和全心采集两种方式,使用Soap-Bubble软件对两种技术采集的CMRA数据进行后处理重组并通过测量冠状动脉各主要分支的长度、直径及血管的锐利度,定量评判CMRA的图像质量.结果 3PPS分段采集CMRA各主要分支的测量值为:长度:右冠状动脉(RCA)(132±13) mm,左冠状动脉系统,即左主干 左前降支(LM LAD)(112±16) mm,左旋支(LCX)(64±11) mm;直径:RCA(3.8±0.5) mm,LM LAD(3.3±0.2) mm,LCX(2.9±0.5) mm;锐利度分别为(49±10)%,(47±11)%,(44±16)%.全心采集:长度:RCA(128±21) mm,LM LAD(101±15) mm,LCX(52±13) mm;直径:RCA(3.5±0.6) mm,LM LAD(3.1±0.4) mm,LCX(3.0±0.7) mm;锐利度分别为(35±15)%,(33±11)%,(30±12)%.两者间的血管锐利度和图像质量差异均有统计学意义(P＜0.05),但长度和直径的差异无统计学意义(P＞0.05).结论 3PPS分段采集较全心采集具有更好的血管锐利度和图像质量,在CMRA的采集方式上建议尽量采用分段采集技术.     

左冠状动脉近段的X线解剖与狭窄发生率的关系

目的 探讨左冠状动脉主干(LM)的X线解剖特征与前降支(LAD)及回旋支(LCX)近段狭窄发生率的关系。方法 搜集2020年8月至2021年3月行冠状动脉造影的患者400例,分别测量其LM的直径、长度、分叉角度、LAD及LCX近段病变的狭窄程度,根据狭窄程度≥50%和<50%将所有患者分别分为LAD、LCX、LM分支显著狭窄组和非显著狭窄组,并引入性别、年龄、高血压、糖尿病、高血脂、吸烟史等临床指标。分析LM分支近段显著狭窄与各临床指标的关系及显著狭窄的独立危险因素。结果 所有患者中,LM直径(4.28±1.04) mm, LM长度(11.90±5.52) mm, LM分叉角度(73.20±37.83)°,男性患者LM分叉角度明显大于女性,其差异有统计学意义(P<0.05);LM分支近段狭窄发生率男性(175/240,72.92%)高于女性(100/160,62.50%),其差异有统计学意义(P<0.05);LAD、LCX及LM分支近段有显著狭窄与无显著狭窄患者年龄及LM直径相比较差异均有统计学意义(P<0.05);Logistic回归分析显示除传统的因素外,L...     

含服硝酸甘油对64层螺旋CT冠状动脉成像质量影响的分析

目的 定量评估64层CT在冠状动脉成像中含服和不含服硝酸甘油对冠状动脉显示的差异.方法 分别在相对时段中对含服硝酸甘油(A组)和不含服硝酸甘油(B组)的各100例患者进行64层CT冠状动脉检查,2组受检者均采用回顾性后门控智能mA扫描技术.分别选取左、右冠状动脉的最佳期相进行MPR、MIP、CPR、VR重组.对2组图像分别进行冠状动脉10个测量点管径的测量,并对右冠状动脉、前降支、回旋支3支冠状动脉显示的分支数目进行统计,然后对2组图像管径测量值和分支数目采用完全随机的两样本均数t检验进行统计学比较.结果 右冠状动脉近、中、远段管径A组比B组分别增加0.29、0.17、0.11mm,扩张率分别为8.0%、5.0%、4.0%;前降支分别增加0.40、0.23、0.10 mm,扩张率分别为11.0%、8.0%、4.7%;回旋支分别增加0.42、0.35、0.12 mm,扩张率分别为13.5%、12.5%、5.5%;左主干增加0.31 mm,扩张率7.8%.A组较B组分支数目增加率,右冠状动脉、前降支、回旋支分别为83%、80%、113%.A、B 2组冠状动脉10个血管节段中,右冠状动脉近段、左主干、前降支近、中段、回旋支近、中段差异有统计学意义(t值分别为3.86、3.74、5.35、3.58、5.29、4.64,P值均＜0.01);右冠状动脉中、远段、前降支远段、回旋支远段差异亦有统计学意义(t值分别为2.13、2.58、2.35、2.14,P值均＜0.05).结论 服用硝酸甘油能有效扩张冠状动脉并能有效增加冠状动脉分支的显示,从而提高64层CT冠状动脉成像质量.     

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.     

Non-invasive coronary angiography with 16-slice spiral computed tomography: image quality in patients with high heart rates

The purpose of this study was to assess segment image quality at high heart rates using 16-slice computed tomography and differential reconstruction for major coronary vessels. According to the following protocol, 16-slice CT coronary angiography in 46 patients with a mean heart rate of 86.3+/-11.8 was reconstructed. At three transverse planes, preview series were obtained and motion artifacts evaluated in 5% increments from 0-95% within the cardiac cycle. Relying on image quality in the previews, reconstructions were performed at three z-positions for each patient. Segment image quality was assessed in terms of artifacts and visibility. The effects of heart rate and trigger delay on image quality were analyzed. Optimal image quality was achieved at 25 to 35% of the cardiac cycle for the left circumflex (CX) and right coronary artery (RCA) or 30 to 40% for the left main (LM) and left anterior descending artery (LAD). Sixteen-slice CT and differential reconstruction produced good image quality with a low percentage of motion-degraded proximal and middle segments (8.8%). Grades were 1.5 for the LM, 1.9 for the LAD, 2.0 for the CX and 2.3 for the RCA. At high heart rates, good image quality of the coronary arteries is achieved by 16-slice CT and a sophisticated reconstruction strategy at peak to late systole.     

Evaluation of free-breathing three-dimensional magnetic resonance coronary angiography with hybrid ordered phase encoding (HOPE) for the detection of proximal coronary artery stenosis.

We evaluated free-breathing, prospective navigator-gated, three-dimensional (3D) magnetic resonance coronary angiography (MRCA) with hybrid ordered phase-encoding (HOPE), in the detection of proximal coronary artery stenosis. The coronary arteries were imaged in 46 patients undergoing cardiac catheterization. The mean scan time was 48 minutes. The mean arterial length (mm) visualized was left main stem (LMS) 11.7 (SD 4.5), left anterior descending (LAD) 30.1 (SD 11.1), circumflex (LCx) 15.5 (SD 8.6), and right (RCA) 56.2 (SD 20.8). Twenty-three patients had coronary artery disease with 47 significant stenoses on cardiac catheterization. All LMS were normal on both catheterization and MRCA. MRCA sensitivity was highest for the LAD (89% CI 65%-99%) and RCA (76% CI 50%-93%), but lower for the LCx (50% CI 21%-79%). Specificity ranged from 72%-100%. Improvements in image quality, length of vessel seen, and specific imaging of the LCx are required for MRCA to become an alternative to cardiac catheterization.     

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.