磁共振成像在异位心脏移植中的应用价值

目的应用MRI观察冠状动脉旁路移植术联合室壁瘤切除术+异位心脏移植术后心脏结构、功能等变化。方法对5例行自体心脏冠状动脉旁路移植术联合室壁瘤切除术+异位心脏移植术患者,采用1.5T超导MRI扫描仪对心脏形态、功能、心肌灌注、延迟增强等进行综合评价。3例术前行MRI检查,5例术后1～17个月先后3次行心脏MRI扫描。结果5例患者术后临床症状均明显改善。3例手术后自体心脏左心室腔均较术前缩小,仅1例心功能明显提高,LVEF从18.4%提高到47.2%。移植术后5例患者中2例自体心脏左心室功能明显改善,LVEF分别上升至47.2%和52.1%,其供体心脏左心室收缩功能低下,LVEF分别为18.4%和22%;3例自体心脏功能恢复不佳的患者,供体心脏左心室收缩功能良好。所有供体心脏心肌首过灌注与延迟增强均无异常信号;所有自体心脏心肌首过灌注与延迟增强均无显著变化。结论MRI一站式无创性检查方法是异位心脏移植术较理想的评估方法。     

心肌梗塞的磁共振成像诊断进展

磁共振成像是一种独特的非创性、具有优质空间分辨力的诊断方法，可清晰显示并分辨梗塞，缺血心肌和正常心肌，测定梗塞面积，局部运动失调，收缩期室壁增厚改变及心功能指标，并与左室造影，同位素显像及二维超声心动图相关性良好，也能显示心腔内附壁血栓，梗塞区及周围出血，近来用顺磁性造影剂后能改善信号／噪声比?提高图像质量，磁共振波谱分析能测定心肌代谢，潜在冠脉显像，多维成像能力使之有进一步发展的潜力。     

磁共振成像在鉴别心肌梗死后左心室室壁瘤中的应用

目的 探讨心脏磁共振成像(MRI)鉴别诊断心肌梗死后左心室真、假性室壁瘤的价值.方法 分析经病理证实的心肌梗死后左心室室壁瘤患者共26例(男22例,女4例).所有患者均行心脏MRI、超声心动图及冠状动脉造影检查,并与病理检查结果对照.结果 患者平均年龄(59.3±9.3)岁.其中胸闷气短24例,15例伴发高血压.超声心动图检查诊断左心室真性室壁瘤22例,假性室壁瘤4例;左心室附壁血栓5例,左心室射血分数为36.9%±9.1%.心脏MRI发现24例患者受累左心室壁厚度＜5.5 mm,2例患者厚度5.5～8.0 mm.24例患者左心室室壁存在矛盾运动,2例患者受累室壁无运动;左心室舒张末期横径(67.8±9.3)mm,室壁瘤最宽处直径(35.1±13.8)mm.心脏MRI诊断真性室壁瘤23例,假性室壁瘤3例,7例患者左心室存在附壁血栓.与病理结果对照,心脏MRI诊断结果与病理一致,而超声心动图检查误诊假性室壁瘤1例,漏诊左心室附壁血栓2例.结论 心脏 MRI 能够准确鉴别心肌梗死后左心室真、假性室壁瘤.

Abstract：

Objective To observe the value of cardiac magnetic resonance imaging(MRI)for differentiation of true from false left ventricular aneurysm in patients after myocardial infraction(MI).Methods Twenty-six patients[22 males/4 females, mean age(59.3 ± 9. 3)years]with left ventricular aneurysm after MI were imaged with MRI, echocardiography and coronary angiography. The respective findings were compared with surgical pathology results. Results There were 24 patients with dyspnea and 15patients with hypertension. LVEF measured by echocardiography was 36. 9% ±9. 1% in this patient cohort.Cardiac MRI showed that the left ventricular end diastolic wall thickness was thinner than 5.5 mm in 24cases, and between 5.5 to 8 mm in 2 cases. The dimension of left ventricle was(67. 8 ± 9. 3)mm.Dyskinesia presented in 24 cases, and akinesia in 2 cases. Delayed enhancement was shown in all cases by MRI. Cardiac MRI detected left ventricular true aneurysm in 23 cases, false aneurysm in 3 case and left ventricular thrombi in 7 cases. The diagnosis by magnetic resonance imaging corresponded well to pathological findings. Echocardiography misdiagnosed pseudoaneurysm in 1 patient, and failed to detected left ventricular thrombi in 2 cases. Conclusion Cardiac MRI could correctly differentiate true from false left ventricular aneurysm in patients after MI.     

磁共振成像、超声心动图、心电图诊断心肌梗塞及其合并室壁瘤的比较

对１７例心肌梗塞（ＭＩ）及ＭＩ并室壁瘤（ＶＡ）患者进行磁共振成像（ＭＲＩ）、二维超声心动图（２－ＤＥ）、心电图（ＥＣＧ）三项检查并与冠状动脉及左心室造影作对照。结果表明，ＭＲＩ对ＭＩ及ＭＩ并ＶＡ的诊断较ＥＣＧ及２－ＤＥ具有更高的诊断价值，提示ＭＲＩ可作为ＭＩ及ＭＩ并室壁瘤的补充诊断方法。     

磁共振成像、超声心动图和心电图诊断心肌梗塞合并室壁瘤的比较

本文对急性心肌梗塞(AMI)后≥3个月者37例分别进行磁共振成像(MRI)、二维超声心动图(2-DE)和心电图(ECG)检查,按室壁(VA)诊断标准,MRI检出率为37.8%(14例),2-DE检出率为32.4%(12例)。将持续性ST段抬高≥3个导联和≥4个导联作为ECG诊断心肌梗塞并发VA的诊断条件,参照MRI结果,敏感性分别为85.7%和71.4%,特异性分别为69.6%和73.9%;以2-DE作对照,敏感性分别为75%和66.7%,特异性为60%和68%。本文还讨论了三种方法诊断心肌梗塞合并VA的临床应用和价值。     

首过及延迟增强的磁共振成像技术在心肌梗死中的价值

目的评价造影剂增强的磁共振成像技术在心肌梗死中的作用。方法共有23例患者入选,经过动态观察患者的症状、心电图和心肌酶谱,有20例患者确诊为心肌梗死,所有患者都完成冠状动脉造影和造影剂增强的磁共振检查。结果20例患者在造影剂增强的磁共振成像时,梗死部位首过显示为低强化区,延迟增强时显示为高强化区,测定梗死面积为(16·58±9·73)%,梗死面积与肌酸激酶峰值、肌钙蛋白T峰值有明显相关性(分别R=0·821,P<0·01和R=0·565,P<0·05)。磁共振成像测定的射血分数为0·46±0·13,左室造影测定的左室射血分数为0·49±0·16,两者差异无统计学意义,也没有相关性。结论造影剂增强的磁共振成像对心肌梗死起到明确诊断和判断预后的重要作用。     

磁共振扩散加权成像在老年前列腺癌诊断中的应用价值

目的探讨磁共振扩散加权成像(DWI)在老年前列腺癌诊断中的应用价值。方法选择在浙江省景宁县人民医院和台州市立医院经穿刺活检或手术证实前列腺癌患者22例作为前列腺癌组,同期经手术证实前列腺增生患者22例作为前列腺增生组(对照组)。所有患者在手术前均进行DWI扫描,观察前列腺癌组和对照组的一般资料、前列腺癌组和对照组的DWI和ADC图像,比较前列腺癌组未受侵犯前列腺组织和对照组前列腺组织ADC值、前列腺癌组外周带癌ADC值和对照组前列腺组织ADC值。结果前列腺癌组的年龄和对照组的年龄比较没有差异(P0.05),前列腺癌组的前列腺特异性抗原(PSA)水平明显高于对照组(P0.05)。前列腺癌组前列腺癌的DWI表现为高信号,ADC图像呈现为低信号;DWI组肌纤维增生的DWI和ADC图像均表现为不均质的稍低信号,腺体增生的DWI和ADC图像均表现为不均质的高信号。前列腺癌组未受癌组织侵犯的外周带ADC值、腺体增生ADC值、间质增生ADC值和DWI组比较没有差异(P0.05)。前列腺癌组外周带癌ADC值明显低于DWI组(P0.05),前列腺癌组外周带癌ADC值明显低于对照组中央带腺体增生ADC值(P0.05),前列腺癌组外周带癌ADC值明显低于DWI组中央带肌纤维增生ADC值(P0.05)。结论前列腺癌组未受侵犯前列腺组织的ADC值和对照组前列腺组织的ADC值之间没有差异,前列腺癌组外周带癌ADC值明显低于对照组前列腺组织的ADC值,DWI在老年前列腺癌诊断中具有重要意义。     

磁共振成像在胸腔疾病诊断中的应用

本文阐述了近年来胸部磁共振成像(MRI)检查技术的改进,特别是抑制伪影技术的提高。对MRI在胸腔疾病诊断中的应用指征作了介绍。并对肺癌、纵隔肿瘤、胸膜病变以及心脏病变的MRI检查作了综述。     

磁共振成像在甲状旁腺腺瘤诊断中的应用

目的探讨甲状旁腺腺瘤的MRI表现特点。方法40例经手术病理证实的病例进行MRI平扫及增强扫描。结果肿瘤常见于颈下部气管食管隐窝区,颈动脉鞘内侧,也可位于上纵隔; 呈卵圆型,有完整的包膜。可出现坏死、液化及囊性变; MRI表现T1WI呈等、等高及等低信号,T2WI上呈高信号,坏死、囊变区信号明显增高,增强扫描后肿瘤明显强化。结论MRI具有较高的软组织分辨能力及三维、多参数成像功能,对甲状旁腺腺瘤的诊断更具优越性、敏感性和准确性。     

功能磁共振成像技术在老年直肠癌诊疗评估中的应用进展

<正>结直肠癌是胃肠道常见的恶性肿瘤之一,随着人们生活和环境的改变,其发病已成为威胁人们健康的主要疾病之一^[1]。在世界范围内,结直肠癌占男性常见恶性肿瘤的第3位,女性的第2位^[2-3]。近年来,以全直肠系膜切除术(total mesorectal excision,TME)联合新辅助放化疗(neoadjuvant radiotherapy and chemotherapy,NRC)的多学科序贯综合治疗模式,已逐步形成直肠癌的综合治疗体系。     

Postmortem unenhanced magnetic resonance imaging of myocardial infarction in correlation to histological infarction age characterization.

AIMS: Postmortem magnetic resonance (MRI) imaging is currently evaluated as alternative to traditional autopsy and myocardial infarction plays a key role therein. The aim of this study is to determine the suitability of postmortem MRI in infarction age staging. METHODS AND RESULTS: In eight human forensic corpses presenting with a total of 11 myocardial infarcted areas, short-axis, transversal, and longitudinal long-axis images (T1, T2, stir, flair) were acquired in situ on a 1.5 T system. During subsequent autopsy, the section technique was adapted to short-axis images. Histological investigations were performed along the entire circumference of the left ventricle to correlate the signal alteration in MR to the histological appearance. Two peracute infarctions were not detected in MRI and autopsy. Four acute infarcted areas presented with decreased signal in necrotic centres and increased signal in marginal myocardial regions (T2-weighted). T1-weighted images showed local hyperintensities when intramyocardial haemorrhage occurred. Four cases showed subacute infarctions with hyperintense regions in T2-weighted images and no signal alteration in T1-weighted images. Four chronic myocardial infarctions showed distinctively decreased signals in all applied sequences. CONCLUSION: Postmortem MRI demonstrates myocardial infarction in situ and allows for an infarction age estimation based on the signal behaviour.     

Fragmented QRS complexes are not hallmarks of myocardial injury as detected by cardiac magnetic resonance imaging in patients with acute myocardial infarction

Background

Q waves on a 12-lead electrocardiography (ECG) are considered to be classic hallmarks of prior myocardial infarction. However, one study suggested that the fragmented QRS complex (fQRS) on ECG is a highly sensitive and specific marker of myocardial scarring on a nuclear stress test. The study aimed to investigate the diagnostic accuracy of fragmented QRS complexes compared with Q waves for myocardial injury detected by delayed contrast-enhanced cardiovascular magnetic resonance imaging (DE-CMRI) in subjects with acute myocardial infarction.

Methods

Electrocardiograms of 190 subjects with myocardial infarction who underwent DE-CMR were analyzed. fQRS was defined by the presence of an additional R wave (R″), or notching of the S wave, or more than one R′ in two contiguous leads.

Results

Delayed enhancement was observed in 180 (94.7%) patients. Transmural enhancement was noted in 78 (43.3%) and subendocardial enhancement in 102 (56.7%) patients. The sensitivity and specificity of Q waved and fQRS for diagnosing delayed enhancement were 59.4% vs. 66.7% and 90.0% vs. 40.0%. The area under the receiver–operator characteristics curve of delayed enhancement was 0.75 for Q waves and 0.53 for fQRS (p = 0.04). The areas under the ROC curves of the transmurality of delayed enhancement were 0.44 for fQRS and 0.58 for Q waves (p = 0.73).

Conclusions

fQRS has poor accuracy for the detection of myocardial injury compared with Q waves. fQRS and Q waves are not valuable tools for the diagnosis transmural irreversible myocardial injury in acute myocardial infarction.     

磁共振延迟增强显像诊断心肌梗死的临床研究

目的 了解磁共振延迟增强(MR-DE)显像在心肌梗死诊断中的临床意义。方法 42例拟诊冠心病的患者,按临床分为心肌梗死、心肌缺血、正常3组,行MR-DE显像,其中25例行冠状动脉造影(CAG),并按冠脉狭窄程度分为狭窄<50％,50％～99％和100％3组。计算MR-DE检出心肌梗死的敏感性与特异性,并分别分析临床分组和CAG分组的MR-DE结果。结果 利用延迟增强判断心肌梗死,敏感性、特异性和诊断准确性分别为87.5％,94.1％和92.8％。出现延迟增强的比例,在临床分组中,分别为87.5％,8.7％和0％;在CAG分组中,分別为0％,50％和100％。结论 MR-DE显像对心肌梗死诊断有较高临床意义。     

磁共振成像对冠心病陈旧性心肌梗死所致心功能不全的诊断及干细胞移植疗效评价的应用

目的 评价磁共振成像(MRI)在冠心病陈旧性心肌梗死合并心功能不全患者诊断中的价值,并分析干细胞移植手术的疗效.方法 20例冠心病陈旧性心肌梗死患者,男18例,女2例,年龄(59.5±10.1)岁,半均分成2组(每组10例),干细胞移植组行冠状动脉旁路移植术(CABG)+干细胞移植,对照组仅行CABG术,术前均行心脏MRI及双核素单光子发射计算机断层(SPECT)进行存活心肌显像检查,术后6个月复查心脏MRI.用MRI评价干细胞移植后左心功能改善及心脏MRI延迟增强显像判断左室存活心肌的准确性.结果 两组左室射血分数(LVEF)均有明显改善,但手术前后变化值比较差异无统计学意义.干细胞移植组左室舒张末期容积(LVEDV)手术前后变化值为(9.91±39.50)ml,与对照组的(-22.34±31.35)ml比较,差异有统计学意义(P＜0.05);干细胞移植组窒壁增厚率变化值高于对照组(11.40%±11.53%比2.27%±7.20%,P＜0.05),其余两组心功能参数变化值比较差异均无统计学意义.心脏MRI延迟增强显像与氟-18-脱氧葡萄糖(18F-FDG)心肌代谢存活心肌显像具有较好的一致性,Kappa=0.446(P＜0.001).以18F-FDG SPECT心肌代谢显像为金标准,心脏MRI延迟增强显像敏感度为68.3%,特异度为92.5%.结论 MRI能够准确判断冠心病陈旧性心肌梗死患者左室容积和功能,对心肌梗死后存活心肌的判断具有同18F-FDG SPECT相近的特异性,但敏感件略低.MRI可用于心肌十细胞移植前诊断与移植后早期疗效的判定.     

Appropriateness of anteroseptal myocardial infarction nomenclature evaluated by late gadolinium enhancement cardiovascular magnetic resonance imaging

Background

In traditional literature, it appears that “anteroseptal” MIs with Q waves in V1-V3 involve basal anteroseptal segments although studies have questioned this belief.

心肌梗死后室壁瘤形成的诊断分析

目的观察心肌梗死（MI）后影响室壁瘤形成的因素以及临床常用方法的诊断价值。方法经左心室造影证实的23例MI后并发室壁瘤的患者,比较其心电图（ECG）、超声心动图（ECHO）、冠状动脉病变程度和侧支循环建立情况。结果所有患者均有前降支病变,三支病变者占65.2%,仅17.4%患者的侧支循环达到Ⅲ级。ECHO阳性者为17.4%,而ECG可达82.6%。结论多支病变且侧支循环不良的患者MI后易并发室壁瘤,ECG较ECHO对室壁瘤的诊断更敏感。     

磁共振评价磁探针标记的骨髓单个核及骨髓间充质干细胞移植治疗猪急性心肌梗死的疗效

目的 骨髓单个核细胞(BM-MNC)及骨髓间质干细胞(MSC)经磁探针标记后,应用磁共振成像(MRI)观察磁探针标记的BM-MNC(MR-MNC)及MSC(MR-MSC)治疗猪急性心肌梗死(AMI)的疗效.方法 24头小型家猪经皮冠状动脉介入法成功制备AMI模型19头,随机分为MR-MSC组(n=7)、MR-MNC组(n=6)和AMI对照组(n=6),分别经冠状动脉途径植入MR-MSC、MR-MNC(细胞总数1×107)和含菲立磁标记物的磷酸盐缓冲液,MRI爪踪移植细胞并观察8周后不同细胞类型移植对梗死心肌面积及心功能的影响,最后行组织学检查鉴定移植细胞及其功能.结果 MRI示MR-MSC组、MR-MNC组均见呈低信号的标记细胞归巢至呈高信号的梗死心肌区周边或梗死心肌内.与移植前相比,8周后MRI测定梗死心肌而积在标记细胞移植组均明显缩小(MR-MSC组8.5%±0.5%比24.7%±3.1%,P＜0.05;MR-MNC组12.3%±1.5%比26.1%±1.5%,P＜0.05);左室射血分数(LVEF)均有明显提高(MR-MSC组56.9%±1.3%比40.7%±2.0%,P＜0.05;MR-MNC组52.8%±1.4%比41.9%±3.3%,P＜0.05),但MR-MSC组LVEF改善程度优于MR-MNC组(16.2%±1.2%比10.9%±3.0%,P＜0.05).普鲁士蓝染色证实标记细胞分布与MRI所见低信号区分布基本一致.Western blot分析显示心肌再生指标肌球蛋白重链表达在MR-MSC组(100.3±5.5)及MR-MNC组(95.5±4.2)均高于AMI对照组(75.7±5.7);心肌特异性肌钙蛋白T在MR-MSC组(124.0±5.8)及MR-MNC组(118.4±4.4)均高于AMI组(93.3±3.9);心肌重构指标基质金属蛋白酶2(MMP2)/MMP抑制剂1(TIMP1)在MR-MSC组(0.6±0.1)及MR-MNC组(0.6±0.1)低于AMI对照组(4.2±0.2).结论 MR-MSC及MR-MNC可在体分化成表达心肌特异性蛋白的心肌样细胞,延缓心室重构,缩小梗死心肌面积,改善整体心窒收缩功能,且MR-MSC对心功能改善程度优于MR-MNC.