潘生丁负荷增强超高速MRI评价心肌灌注储备的初步研究

目的 评价潘生丁负荷心肌首过灌注储备磁共振成像技术对缺血性心性心脏病的诊断作用。方法 采用１．５ＴＭＲ成像设备对３０位健康志愿者和２１位经核素心肌灌注显像及冠状动脉造影检查确定有心肌缺血的患者进行潘生丁负荷心肌首过灌注储备ＭＲＩ的研究。并对心肌灌液储备的相关参数进行定量分析以及对比研究。结果 以信号强度－时间曲线的峰时（ｔｐ）、最大信号强度增加值（ＳＩｍ）、最大上升斜率（ｓｌｏｐｅ）和平均通过时间     

心肌灌注MRI和MR电影在急性冠状动脉综合征中的应用

目的　评估心肌灌注MRI和MR电影在急性冠状动脉 (简称冠脉 )综合征中的应用价值。方法　急性冠状动脉综合征患者 5 5例 ,再灌注治疗 3～ 6个月后 ,进行心脏MR影像检查。真正快速稳态梯度序列 (FIESTA)用于观察心肌运动 ;快速梯度回波序列 (FGREET)用于观察首过时相心肌灌注的MRI特征 ;反转恢复梯度回波序列 (MDE)用于观察延迟时相心肌灌注MRI特征。结果5 5例中 38例患者可见位于心内膜下心肌的首过灌注缺损 ,其信号强度相对值显著低于周围心肌。心肌灌注延迟时相MRI示 5 1例患者心室壁内存在不同范围的强化灶 ,其信号强度值是周围心肌的4 36倍 (t=1.6 9,P <0 .0 5 )。心室壁内所存在的延迟强化灶范围和信号均匀程度与心室壁运动能力显著相关 (非标准相关系数分别为 - 4 2 195、- 10 1 75 0 ,标准相关系数分别为 - 0 377、0 4 2 5 ;t分别为- 5 735、- 5 4 4 5 ,P值均 <0 .0 0 1)。结论　梗死心肌于MR心肌灌注延迟时相呈现显著强化。通过综合分析延迟强化 ,运动能力显著降低和可能存在的首过灌注缺损 ,可以更有效地识别梗死 (或瘢痕 )心肌     

心肌声学造影评价心肌血流灌注与冠状动脉狭窄的关系

目的 :前瞻性研究心肌声学造影 (MCE)评价冠心病局部心肌血流灌注与冠状动脉狭窄的关系。方法 :用间歇二次谐波、脉冲反转显像综合技术对 48例经冠状动脉造影检查证实的冠心病患者行静态MCE检查。采用 16段划分法 ,对心肌显影进行目测半定量计分 (MCS)分析。计分方法 :回声均匀性增强 ,显影时间≤ 90s为 1分 ;回声低淡不均匀 ,显影延时 ( >90s)为 0 .5分 ,充盈缺损为 0分。结果 :以冠状动脉造影冠状动脉直径狭窄≥ 5 0 %为诊断标准 ,MCE检出冠状动脉狭窄的符合率为 88%(k =0 .75 )。MCS与冠状动脉狭窄程度相关性差 (r =-0 .17)。结论 :MCE技术能较准确的预测冠状动脉狭窄 ,但心肌显影程度并非与冠状动脉狭窄程度一致 ,因除狭窄程度外 ,与狭窄的范围、侧支循环、心肌微血管病变以及心肌声学造影的触发间期也有一定的关系     

腺苷诱导负荷双能心脏CT心肌灌注成像与心脏MRI和传统冠状动脉血管造影的对照研究

目的腺苷负荷双能CT(DECT)与灌注MRI(SP-MRI)和传统冠状动脉血管造影(CCA)比较,评价其探查血流动力学明显狭窄引起的可复性心肌灌注缺损(PD)的可行性     

3.0 T MRI不同脉冲序列对胰腺疾病的诊断价值

目的 探讨MRI检查不同脉冲序列对胰腺病变的诊断价值。方法 对87例临床怀疑胰腺病变的病人应用3.0 T MR设备进行检查,扫描序列包括双回波T1WI（同相位与反相位成像）、脂肪抑制T1WI（T1WI+FS）、脂肪抑制T2WI (T2WI+FS)、磁共振胆胰管水成像（MRCP）、快速多层面扰相梯度回波(FSPGR)动态增强扫描。由2名放射科医师分析不同脉冲序列的MRI所见。结果 正常胰腺15例,急性胰腺炎27例,慢性胰腺炎30例,胰腺癌15例。T1WI+FS显示胰腺形态与信号最佳,正常胰腺呈稍高信号。在双回波T1WI上,胰腺与周围组织对比度降低。胰腺病变在T1WI上表现为低信号50例,T2WI+FS显示胰周渗出性病变34例。MRCP显示胰管扩张35例,胆管扩张20例,双管征9例。快速扰相梯度回波（FSPGR）动态增强显示胰腺癌13例,肿块在动脉期表现为相对低信号,延迟期轻度强化,周围血管受侵2例。结论 合理应用MR扫描序列有助于提高胰腺病变的诊断效能。     

CCTA评价冠状动脉狭窄程度与SPECT心肌灌注显像关系的研究

目的：探讨冠心病患者CCTA不同狭窄程度与SPECT MPI间的关系。方法68例患者进行了CCTA和MPI检查,所有患者均行冠状动脉造影。CCTA按管腔狭窄程度分为5个级别,即0,1%~24%,25%~49%,50%~74%,75%~100%。MPI分为正常和灌注缺损(包括可逆缺损和不可逆缺损)。结果68例患者共204根血管纳入分析。以患者为单位进行分析,40例CCTA显示管腔重度狭窄的患者中,29例(72.5%)MPI显示灌注缺损。另外11例(27.5%)CCTA异常的患者心肌灌注 MPI显示正常。在28例CCTA显示未见明显狭窄的患者中,17例(60.1%)显示心肌灌注正常,而另外11例(39.9%)显示灌注缺损。根据CCTA冠状动脉狭窄程度分组,心肌灌注缺损(包括不可逆性灌注缺损和可逆性灌注缺损)出现的比率：0,1%~24%,25%~49%,50%~74%,75%~100%分别为5(27.7%)/18,1(33.3%)/3,5(71.5%)/7,4(50%)/8,25(78.1%)/32。结论冠状动脉狭窄和灌注缺损的不匹配多发生在冠状动脉中度狭窄的患者。在轻度狭窄和重度狭窄的患者中,二者多匹配。冠状动脉中度狭窄的患者应进行CCTA和 MPI联合检查评价冠心病。     

心肌灌注断层显像与冠状动脉造影诊断冠心病结果比较

核素心肌灌注显像 (ＭＰＩ)和冠状动脉造影 (ＣＡＧ)都是诊断冠心病的重要手段。以往研究认为两者符合率极高[1 ] 。笔者通过半定量法研究ＭＰＩ与ＣＡＧ对冠状动脉病变诊断的符合程度 ,以探讨两种检查在冠心病诊断中的价值。一、资料与方法研究对象为在本院做过ＭＰＩ和ＣＡＧ的 10 0例住院患者 ,其中男 86例 ,女 14例 ,平均年龄 (5 9.9± 10 .1,37～ 81)岁。ＭＰＩ,静脉注射99Ｔｃｍ 甲氧基异丁基异腈 (ＭＩＢＩ) 1110ＭＢｑ(6 5例 )和2 0 1 Ｔｌ 111ＭＢｑ(35例 ) ,其中 4 3例采用潘生丁负荷心肌灌注显像。潘生丁用量为按体重0 .14ｍｇ·…     

心脏冠状动脉磁共振血管造影

应用屏气法连续多角度斜位二维ＴＯＦ对冠状动脉磁共振血管造影临床应用的可行性进行评价。共２３例，２０例为健康者，２例冠脉造影证实有病变，１例超快速ＣＴ显示冠脉有钙化。结果：左冠脉主干、左前降支、左旋支及右冠脉近段在２３例均完全显示，冠脉显示长度超过７ｃｍ者本组病例中左前降支有９例（３９％），左旋支４例（１７％），右冠脉１３例（５７％），２例冠脉造影显示冠脉狭窄≥５０％者磁共振检查均较好显示。     

MRI检测活性心肌初步研究与冠状动脉造影、M型超声对比

目的分析磁共振多技术扫描检测心肌活性的价值。方法应用磁共振多技术扫描对34例临床资料完整的冠心病患者进行检查,并将结果与冠状动脉造影和M型超声结果对照。结果磁共振测得射血分数、每搏射血量和心输出量明显低于超声测值且有统计学意义(P<0.05),磁共振测得舒张末期容积和收缩末期容积比超声测值稍高但无统计学意义(P>0.05)。以冠状动脉造影结果为参考标准,静息心肌灌注扫描检测冠状动脉狭窄50%以上的敏感性为70.4%,特异性为94.2%,总符合率为78.7%。结论磁共振多技术检测活性心肌优于M型超声,与冠状动脉造影有较高符合率。     

Magnetic resonance myocardial perfusion imaging-First experience at 3.0T

Objective

MR myocardial perfusion imaging (MRMPI) is an established technique for the evaluation of the hemodynamical relevance of coronary artery disease. Perfusion imaging at 3.0 T provides certain advantages compared to 1.5 T. Aim of this study was to evaluate myocardial MR perfusion imaging at 3.0 T.

Materials and methods

Twelve patients with stable Angina pectoris and known or suspected coronary artery disease were examined at 3.0 T. Myocardial perfusion was assessed using a saturation recovery gradient echo 2D sequence (TR 1.9 ms, TE 1.0 ms, FA 12°) with 0.05 mmol Gd-DTPA per kg body weight at stress during injection of 140 μg adenosine/kg body weight/min and at rest in short axis orientation. Perfusion analysis was based on a least square fit of the signal/time curve (peak signal intensity, slope). Perfusion series were assessed by two independent observers. Reference for the presence of relevant coronary artery stenoses was invasive coronary angiography. Two experienced observers evaluated the coronary angiograms in biplane projections for the presence and grade of stenoses. Results were compared with the MR perfusion analysis.

Results

All MR examinations could be safely performed and yielded high image quality. In eight patients stress-induced hypoperfusion was detected (stenosis >70% in coronary angiography). In four patients myocardial hypoperfusion was ruled out (stenosis <70%). The myocardial perfusion reserve index was significantly reduced in hypoperfused myocardium with 1.9 ± 1.6 compared to 2.5 ± 1.6 in regularly perfused myocardium (p < 0.05). In coronary angiography, eight patients were found to suffer from coronary artery disease, whereas in four patients coronary artery disease was ruled out.

Conclusion

Our initial results show that MRMPI at 3.0 T provides reliably high-image quality and diagnostic accuracy.     

3.0 T非增强全心冠状动脉MR成像评价冠状动脉狭窄的初步研究

目的 评价3.0T非增强全心冠状动脉MR血管成像(CMRA)诊断冠状动脉狭窄的临床价值.方法 对33例冠状动脉CT血管成像(CCTA)诊断冠状动脉有意义狭窄(＞50％)且拟行冠状动脉造影(CAG)的患者行冠状动脉MR血管成像(CMRA)检查.应用3.0T扫描仪及32通道成像线圈,采用非对比增强、心电门控触发、呼吸导航、T2预置脉冲以及脂肪抑制的三维梯度回波序列.利用美托洛尔降低心率至＜ 80次/min.采用配对样本Wilcoxon秩检验分析CMRA及CCTA在冠状动脉近中段及远段评分的差异性.以CAG结果为金标准,评价CMRA诊断冠状动脉近中段＞50％狭窄的准确性以及与CCTA的一致性.结果 33例患者中30例成功完成CMRA扫描,CMRA及CCTA 在冠状动脉近中段的评分相近[CMRA:(3.49±0.61)分,CCTA:(3.56±0.55)分,Z=-1.715,P＞0.05],CCTA评价冠状动脉远段明显优于CMRA[CMRA:(2.44±0.76)分,CCTA:(3.23±0.60)分,Z=-6.159,P＜0.05].CMRA及CCTA在以段为基础诊断冠状动脉近中段＞50％狭窄的一致性良好(Kappa=0.779,P＜0.05).CMRA诊断的敏感度、特异度、阳性预测值及阴性预测值分别为84.1％ (37/44)、85.8％ (115/134)、66.1％(37/56)、94.3％ (115/122),CCTA分别为88.6％ (39/44)、89.6％ (120/134)、73.6％ (39/53)、96.0％ (120/125).结论 3.0T非增强全心CMRA及CCTA诊断冠状动脉近中段狭窄的准确性相似,但CMRA诊断冠状动脉远段的狭窄需进一步深入研究.     

Comparison of intraarterial MR angiography at 3.0 T with X-ray digital subtraction angiography for detection of renal artery stenosis in swine

PURPOSE: To compare the accuracy of catheter-directed intraarterial (IA) magnetic resonance (MR) angiography at 3.0 T with that of x-ray digital subtraction angiography (DSA) for the measurement of renal artery stenosis (RAS) in swine. MATERIALS AND METHODS: Unilateral hemodynamically significant RAS (>50%) was induced surgically in six pigs with use of reverse cable ties. One to two weeks after surgery, each pig underwent x-ray DSA and MR angiography before and after percutaneous transluminal balloon angioplasty (PTA). X-ray DSA was performed before and after PTA of RAS by injection of iodinated contrast agent through a 5-F multiple-side hole angiographic catheter placed in the abdominal aorta under fluoroscopic guidance. MR angiography of RAS was performed before and after PTA of RAS on a 3.0-T clinical MR imager with use of gadolinium-based contrast agent. MR angiography and DSA images were analyzed with the full width at half maximum method. Percent stenosis measurements between x-ray DSA and MR angiography were compared with a paired t test and were correlated with linear regression and Bland Altman analysis (alpha = 0.05). RESULTS: Six cases of RAS were induced and imaged successfully with DSA and MR angiography techniques before and after PTA. On x-ray DSA, median stenoses was 64% (95% CI 57%-80%) before PTA and 20% (95% CI 5%-32%) after PTA. Corresponding MR angiography median stenosis measurement was 69% (95% CI 58%-80%) before PTA and 26% (95% CI 16%-36%) after PTA. A paired t test comparison did not show a difference between DSA and MR angiography (P = .16). RAS measurements on MR angiography correlated closely (P < .01) with DSA measurements (r(2) = 0.92). CONCLUSION: In swine, the accuracy of catheter-directed IA MR angiography with use of a clinical 3.0-T MR imaging unit for the measurement of RAS was similar to that of conventional x-ray DSA.     

Quantitative coronary arterial stenosis assessment by multidetector CT and invasive coronary angiography for identifying patients with myocardial perfusion abnormalities

Background

Semi-quantitative stenosis assessment by coronary CT angiography only modestly predicts stress-induced myocardial perfusion abnormalities. The performance of quantitative CT angiography (QCTA) for identifying patients with myocardial perfusion defects remains unclear.

Methods

CorE-64 is a multicenter, international study to assess the accuracy of 64-slice QCTA for detecting ??50% coronary arterial stenoses by quantitative coronary angiography (QCA). Patients referred for cardiac catheterization with suspected or known coronary artery disease were enrolled. Area under the receiver-operating-characteristic curve (AUC) was used to evaluate the diagnostic accuracy of the most severe coronary artery stenosis in a subset of 63 patients assessed by QCTA and QCA for detecting myocardial perfusion abnormalities on exercise or pharmacologic stress SPECT.

Results

Diagnostic accuracy of QCTA for identifying patients with myocardial perfusion abnormalities by SPECT revealed an AUC of 0.71, compared to 0.72 by QCA (P?=?.75). AUC did not improve after excluding studies with fixed myocardial perfusion abnormalities and total coronary arterial occlusions. Optimal stenosis threshold for QCTA was 43% yielding a sensitivity of 0.81 and specificity of 0.50, respectively, compared to 0.75 and 0.69 by QCA at a threshold of 59%. Sensitivity and specificity of QCTA to identify patients with both obstructive lesions and myocardial perfusion defects were 0.94 and 0.77, respectively.

Conclusions

Coronary artery stenosis assessment by QCTA or QCA only modestly predicts the presence and the absence of myocardial perfusion abnormalities by SPECT. Confounding variables affecting the relationship between coronary anatomy and myocardial perfusion likely account for some of the observed discrepancies between coronary angiography and SPECT results.     

Silicosis-induced pulmonary artery stenosis: demonstration by MR angiography and perfusion MRI

Silicosis is a common occupational disease. We present a 64-year-old male patient suffering from symptomatic silicosis due to compression of the pulmonary arteries by enlarged hilar lymph nodes. Clinical symptoms and diagnostic imaging modalities are described, with emphasis on cross-sectional imaging. MR angiography and perfusion MRI of the lung in silicosis are described, and their diagnostic value in pneumoconiosis is discussed.     

Reconciling discordant myocardial perfusion imaging and coronary angiography

A common clinical conundrum presents itself in the discordance between nuclear stress testing and invasive coronary angiography (ICA) in the patient presenting with angina. A patient with an abnormal perfusion scan and “normal coronary angiography” may result in the patient’s symptoms being dismissed as “non-cardiac.” Alternatively, a patient with a “normal perfusion study,” who nonetheless undergoes ICA and is found to have significant coronary artery disease may confound efforts to risk stratify and potentially treat patients with angina. This paper will review the current evidence to explain these apparent paradoxical scenarios.     

心肌灌注断层显像和冠状动脉造影结果不一致分析

回顾性分析了４０８例住院病人冠状动脉造影（ＣＡＧ）和心肌灌注显像（ＭＰＩ）的资料。所有ＭＰＩ检查用Ｔｏｓｈｉｂａ９０Ｂ型ＳＰＥＣＴ仪和Ｓｉｅｍｅｎｓ三探头ＳＰＥＣＴ仪完成。以ＣＡＧ示冠状动脉狭窄≥５０％为有临床意义的冠状动脉狭窄，４０８例中ＣＡＧ结果和ＭＰＩ结果不符合者２５例（６１％）。２５例病人平均年龄５１７±１０５岁，男２２例，女３例。ＭＰＩ显示心肌缺血和（或）心肌梗塞而ＣＡＧ正常者１５例，其中临床诊断为Ｘ综合征７例、陈旧性心肌梗塞３例、心绞痛（冠状动脉狭窄３０％～４０％）、高血压病、心肌肿瘤、扩张型心肌病和睡眠呼吸暂停综合征各１例；ＭＰＩ显示正常而ＣＡＧ有临床意义狭窄者共１０例（狭窄５０％～６０％者５例次，累及右冠状动脉者５例次，分支狭窄者５例次，运动量不足１例次，伴良好侧支循环２例次）。因此，心肌断层显像不正常而ＣＡＧ正常者，不能认为显像均为假阳性，其中有７３％的ＭＰＩ诊断与临床诊断符合；心肌显像阴性、ＣＡＧ证实狭窄≥５０％，大部分为冠状动脉远端分支狭窄和临界性冠状动脉狭窄及右冠状动脉狭窄或为运动量不足。