肥厚型心肌病的磁共振影像诊断应用初探

目的 评价肥厚型心肌病的磁共振影像诊断价值。材料与方法 ２０例肥厚型心肌病患者,行磁共振ＴＳＥ多层面平扫和磁共振电影（ｃｉｎｅ－ＭＲＩ）检查,用ＡＲＧＵＳ专用心功能分析软件分析左室心肌质量、各节段心壁厚度及心肌增厚率等参数。结果 （１）肥厚型心肌病主要累及室间隔及左室前、侧壁,呈非对称分布,肥厚心肌与左室后下壁比率≥１．５。（２）肥厚心肌的心肌增厚率显著低于正常心肌（Ｐ〈０．０１）。（３）梗阻型左     

主动脉夹层几种磁共振影像的评价和比较

目的：评价和比较ＭＲＩＳＥ常规序列、电影（ｃｉｎｅ）ＭＲＩ及ＭＲ血管造影（ＭＲＡ）对主动脉夹层的诊断价值。材料和方法：对２５例主动脉夹层进行了３１人次ＭＲ检查。其中包括胸腹主动脉ＳＥ序列３１人次，胸主动脉ｃｉｎｅＭＲＩ２３人次及腹主动脉二维时间飞跃（２ＤＴＯＦ）ＭＲＡ２１人次。将ｃｉｎｅＭＲＩ及ＭＲＡ分别与其相应ＳＥ序列ＭＲ表现进行比较。结果：胸主动脉ｃｉｎｅＭＲＩ２３例与相应ＳＥ序列比较，两者所有病例均显示内膜片及真假两腔，但显示破口分别为１４和９例。显示头臂血管受累分别为７和２条。腹主动脉ＭＲＡ２１例与相应ＳＥ序列比较，两者均显示内膜片和真假两腔，但显示破口或再破口者分别为４和２例，腹主动脉分支血管受累分别为３９和１４条。结论：ＭＲ是诊断主动脉夹层的最佳影像学方法之一。在常规ＳＥ序列基础上，辅以ｃｉｎｅＭＲＩ和ＭＲＡ技术将大大提高ＭＲ总体观察夹层范围、内膜破口以及分支受累的能力，给临床提供更多的信息。     

亚急性和慢性心肌梗塞的MRI诊断和评价

目的：确定自旋回波（ＳＥ）和电影动态ＭＲＩ（ｃｉｎｅＭＲＩ）评价亚急性和慢性心肌梗塞信号变化、室壁节段运动和其他合并症的价值。材料和方法：对心肌梗塞亚急性期５例和慢性期１３例进行ＭＲ横断面、左室长／短轴Ｔ１ＷＩ，其中１３例还经Ｔ２ＷＩ，５例经Ｇｄ－ＤＴＰＡ增强。结果：前壁（包括前间壁）受累６例，下壁、侧壁和后壁受累各２例，前壁和下壁均受累６例。Ｔ１ＷＩ显示４例梗塞室壁信号略低，４例亚急性期注射Ｇｄ－ＤＴＰＡ后强化，慢性期１１例室壁厚度变薄；ｃｉｎｅＭＲＩ显示１５例室壁节段运动减低；发现合并二尖瓣返流６例、主动脉瓣返流４例、心包积液４例。结论：ＳＥ和ｃｉｎｅＭＲＩ能较好地显示心肌梗塞的部位、范围和室壁厚度，ｃｉｎｅＭＲＩ评价室壁节段运动和瓣膜返流更具优势     

颅内原发性肿瘤动态增强MRI探讨

目的：探讨动态增强ＭＲＩ对颅内原发性肿瘤的诊断价值。材料与方法：使用１．０ＭＲＩ系统（Ｍａｇｎｅｔｏｍ Ｉｍｐａｃｔ,Ｓｉｅｍｅｎｓ）ＳＥ序列对７２例颅内原发性肿瘤进行动态增强扫描,分析各种肿瘤的对比增强率－时间（ＣＥＲ－Ｔ）曲线类型、 增强峰值（ＥＰ）及最大对比增强率（ＭＣＥＲ）。结果：ＥＰ在９０秒内见于３例血管瘤型脑膜瘤、１例血管母细胞瘤及１例脉络膜乳头状瘤;２６例星形细胞瘤仅４例Ⅲ、Ⅳ级的Ｅ     

先天性主动脉缩窄的磁共振成像诊断

目的研究先天性主动脉缩窄（ＣｏＡ）的磁共振成像（ＭＲＩ）征象并与超声心动图（Ｅｃｈｏ）和手术对照，探讨其在诊断中的意义和作用。方法ＣｏＡ１２例，单纯型１０例，复杂型２例。１０例经手术证实，１例行ＤＳＡ，１例行血管造影和经皮主动脉球囊成形术。ＭＲＩ均行ＳＥ序列成像，其中８例兼作梯度回波（ＧＲＥ）的电影（ｃｉｎｅ）ＭＲＩ或（和）ＭＲ血管造影（ＭＲＡ）。所有病例均有经胸Ｅｃｈｏ检查。结果９例（７５％）ＭＲＩ显示为局限性膜状或嵴状狭窄，３例（２５％）呈长管状狭窄。８例ｃｉｎｅＭＲＩ或（和）ＭＲＡ均能显示狭窄段和扩张的肋间动脉和乳内动脉等侧支循环。１２例ＣｏＡ，ＭＲＩ均获得正确诊断，Ｅｃｈｏ８例（６６．７％）获正确诊断。结论ＭＲＩ是检查ＣｏＡ的一种优良的无创性方法，能准确判断狭窄部位、形态、范围和程度，显示狭窄前、后主动脉及头臂血管改变，以及侧支循环情况。对ＣｏＡ的诊断优于Ｅｃｈｏ，基本上可取代血管造影检查。     

血管紧张素系统在烧伤后心肌损害及心功能障碍中的作用

目的观察心肌局部肾素－血管紧张素系统（ＲＡＳ）在烧伤早期心肌损害及心功能障碍中的作用。方法测定烧伤前（对照组）及烧伤后３,８,２４小时左心功能变化、血浆心肌球蛋白轻链１（ＣＭＬＣ１）含量、心肌血管紧张素转换酶（ＡＣＥ）活性、血管紧张素Ⅱ（Ａｎ）及钙离子（Ｃａ２＋）含量,测定心肌肌浆网（ＳＲ）Ｃａ２＋－ＡＴＰａｓｅ活性及ＳＲＣａ２＋转运功能。结果烧伤大鼠左心室收缩功能明显降低,ＣＭＬＣ１显著升高,心肌ＡＣＥ活性、Ａｎ及Ｃａ２＋含量增加,ＳＲＣａ２＋－ＡＴＰａｓｅ活性降低,ＳＲ　Ｃａ２＋摄取减少。预防性给予ＡＣＥ抑制剂可显著降低烧伤后心肌ＡＣＥ活性,减少Ａ。产生,使血浆ＣＭＬＣ１下降、Ｃａ２＋含量降低,增加ＳＲＣａ２＋－ＡＴＰａｓｅ活性、ＳＲＣａ２＋摄取,明显改善左心室功能。结论心肌局部ＲＡＳ激活参与烧伤后心肌损伤,抑制ＳＲＣａ２＋转运可能是其促进心功能障碍的机制之一。     

磁共振电影成像估价心肌功能

采用磁共振电影成像（Ｃｉｎｅ－ＭＲＩ）估价９例正常人和１３例左心室陈旧心肌梗塞患者的左心室功能状况。其方法是应用小角度翻转角、短ＴＲ和信号聚焦的梯度场成像序列，通过观察左心室各段肌壁运动状态和测量肌壁厚度的变化以判断各段肌壁的运动功能。结果提示，Ｃｉｎｅ－ＭＲＩ无论对心肌壁运动状态的定性还是运动功能的定量均有一定的价值。     

1 H磁共振波谱在新生儿缺氧缺血性脑病中的应用

目的 结合ＭＲＩ探讨＾１Ｈ磁共振波谱（＾１Ｈ ＭＲＳ）在新生儿缺氧缺血脑病９ＨＩＥ）中的应用价值。方法 选择３８例经临床确诊为ＨＩＥ的足月新生儿进行ＭＲＩ及＾１Ｈ ＭＲＳ检查。年龄５－１７天,平均８．２天,对其中的２６例必于６个月以后分别进行随访和（或）复查ＭＲＩ。同时选择８例无窒息史的健康足月新生儿做对照研究。ＭＲＩ检查采用Ｅｌｓｃｉｎｔ２．０超导型磁共振扫描系统,应用ＳＥ序列进行常规扫描,＾１     

肥厚型心肌病的磁共振成像研究

作者分析了经ＭＲＩ诊断的１１９例肥厚型心肌病磁共振成像所见，主要有：室间隔或／和右室壁肌肥厚，肥厚心肌为均匀一致中等信号，向心腔内凸出，致室腔缩小、变形，收缩期增厚率下降。作者还对肥厚型心肌病的ＭＲＩ诊断价值和诊断标准进行了探讨。     

99mTc-MIBI肺心摄取比值评估PTCA术前后心脏功能

９９ｍＴｃ－ＭＩＢＩ心肌摄取率是反映心肌血流灌注、细胞完整性和功能状态的标志。近年来许多研究证实,在心肌显像时肺部９９ｍＴｃ－ＭＩＢＩ滞留量与左心室功能状态相关。（１－３）本研究在９９ｍＴｃ－ＭＩＢＩ心肌灌注显像同时采用肺心摄取比值（ＬＨＲ）定量分析法,并与超声心动的ＬＶＥＦ比较,观察经皮冠状动脉内成形术（ＰＴＣＡ）治疗前后左心室功能的变化,定量评估左心室功能,为临床判断治疗效果和预后提供依据。１材料和方法１．１　病例选择（１）ＰＴＣＡ治疗组 ３９例经 ＰＴＣＡ治疗的冠心病（ＣＨＤ）患者,男 ３５…     

Comparison of contrast-enhanced MRI with iodine-123 BMIPP for detection of myocardial damage in hypertrophic cardiomyopathy

OBJECTIVE: The purpose of this study was to compare contrast-enhanced MRI with dual-radionuclide SPECT for the detection of myocardial damage associated with hypertrophic cardiomyopathy. SUBJECTS AND METHODS: Twenty-three patients with hypertrophic cardiomyopathy were examined. Delayed hyperenhancement of the damaged myocardium was observed using contrast-enhanced MRI, and regional wall thickness and left ventricular ejection fraction were measured using cine balanced steady-state free precession MRI. Dual-radionuclide SPECT using technetium-99m sestamibi and iodine-123 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) was performed at rest. In the abnormal myocardial segments, agreement between the contrast-enhanced MRI and 123I BMIPP SPECT was assessed. The relationships between the regional and global cardiac abnormalities and the delayed hyperenhancement on MRI and decreased uptake of 123I BMIPP were also evaluated. RESULTS: In 368 left ventricular segments, 57 segments showed delayed hyperenhancement on MRI, 43 segments showed decreased uptake of 123I BMIPP, and seven showed decreased uptake of (99m)Tc sestamibi. The delayed hyperenhancement and decreased uptake of 123I BMIPP were frequently observed in the interventricular septal wall (p < 0.0001); however, the agreement between the methods in detecting myocardial abnormalities was fair (kappa = 0.38). The abnormal septal walls were significantly thicker than those without apparent abnormalities (p = 0.031). There was an inverse correlation between the number of enhancing segments and the ejection fraction (r = -0.53). CONCLUSION: In hypertrophic cardiomyopathy, contrast-enhanced MRI was valuable for the detection of extensive myocardial damage.     

屏气电影法MRI评价左心室功能的价值

目的：探讨MR屏气电影成像技术评价左室功能的价值。方法：应用屏气电影法MRI对18例健康成年志愿者和36例心脏病患者进行检查，并对左室容量和心肌质量进行测量，将屏气电影法MRI的结果与传统电影法MRI及超声心动图进行比较。结果：（1）屏气电影法与传统电影法MRI及超声心动图所得舒张末期容量（EDV）、收缩末期容量（ESV）、射血分数（EF）相关性良好，相关系数为0．52－0．96，3种方法所测各指标的均值间比较差异无显著性意义（P＞0．05）。（2）3种方法所测舒张末期心肌质量（EDM），收缩末期心肌质量（ESM）相关系数较前3个指标低，且MRI与超声心动图所测ESM的均值差异有显著性意义（P＜0．05），MRI与超声心动图ESM测量的一致性欠佳。结论：屏气电影法MRI与传统电影法MRI、超声心动图比较，各心功能指标测量准确，相关性好，且成像时间短，无呼吸运动伪影，是1种临床实用价值很高的技术。     

肥厚型心肌病的MRI诊断

目的：探讨磁共振成像(MRl)对肥厚型心肌病(HCM)的诊断价值，并与超声心动图的结果相对比；同时通过磁共振电影观察心脏功能的改变及心室壁厚度于心动周期内的变化情况。材料和方法：15例肥厚型心肌病患者，MRI扫描时应用心电门控，分别进行自旋回波(SE)序列和梯度回波(GE)序列(电影)检查观察心室壁和心内血流动力学的改变；同时进行超声心动图检查。结果：于舒张末期在左心室中部水平(短轴位)分别测得心室前壁、侧壁、后壁和室间隔的室壁厚度，在心脏长轴位测得心尖部的室壁厚度，并与二维超声结果相比较，并根据心脏电影MRI计算出室间隔和心室侧壁的室壁增厚率。结论：(1)肥厚型心肌病以心室壁的异常肥厚为特点，MRI表现既有左室壁对称性普遍肥厚；亦有非对称性局部心肌肥厚的各类亚型。根据血流动力学的改变MRI可区分梗阻型和非梗阻型。(2)对于心室(前)侧壁、心尖部和室间隔局限性增厚的HCM，MRI能准确定位和分段，对室壁厚度的测量较二维超声心动图亦更准确。(3)电影MRI可反映心动周期内心腔内的血流动力学改变；同时更清楚地显示出心肌于舒张期和收缩期不同时相的动态变化情况。     

First-pass myocardial perfusion defect and delayed contrast enhancement in hypertrophic cardiomyopathy assessed with MRI.

BACKGROUND: Gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) enhanced magnetic resonance imaging (MRI) is known to be useful for detecting myocardial injury. In this study, we used first-pass myocardial perfusion and delayed contrast-enhanced MRI to determine whether an abnormal signal intensity was related to the left ventricular regional contractile function in patients with hypertrophic cardiomyopathy (HCM). MATERIALS AND METHODS: Twelve patients with HCM participated in this study. Four short axial cine images of the left ventricle were acquired. Subsequently, first-pass myocardial perfusion images during the first passage of Gd-DTPA (0.1 mmol/kg), and delayed contrast-enhanced images after a 15-min delay, were acquired in the same orientation as cine imaging. Each image was divided into eight blocks and a total of 384 blocks were analyzed. RESULTS: First-pass myocardial perfusion defects (PD) were detected in nine patients with an average of 11.5+/-11 blocks. Delayed contrast enhancement (DE) was detected in 11 patients with an average of 11.5+/-10 blocks. Mean wall thickness in PD blocks (16.7+/-4.7 mm) was larger than that in normal perfusion blocks (13.6+/-3.9 mm, p<0.001). Mean wall thickness in DE blocks (16.9+/-4.9 mm) was larger than that in normal enhanced blocks (13.4+/-3.6 mm, p<0.001). PD were located at almost the same site as DE, but DE areas were larger than PD areas (p=0.0021). Mean percent wall thickening of blocks with PD (63.1+/-44.7%, p<0.0001) and blocks with DE (75.2+/-81.5%, p<0.01) was lower than that in blocks with neither PD nor DE (103.5+/-66.0%). Significant correlations were found between percent wall thickening and percent PD (r=0.46, p<0.0001) and between percent wall thickening and percent DE (r=0.54, p<0.0001). CONCLUSION: Abnormal signal intensity from first-pass myocardial perfusion and delayed contrast-enhanced MRI are closely related to left ventricular regional contractile function.     

Cardiac cine MRI: Quantification of the relationship between fast gradient echo and steady-state free precession for determination of myocardial mass and volumes

PURPOSE: To determine the correlation function between the steady-state free precession (SSFP) and fast gradient echo (FGRE) cine MRI pulse sequences for measuring the myocardial mass and volumes. MATERIALS AND METHODS: Cardiac cine MRI examinations were acquired in 50 individuals (female: 35, male: 15, mean age 64.1 +/- 9.1 years, range 48-83) using SSFP and FGRE cardiac pulse sequences. RESULTS: The mean (standard deviation [SD]) left ventricular end diastolic volume measured by SSFP was significantly larger (4.5%) than by FGRE (P < 0.001); this was also the case for end systolic volume (15.0%, P < 0.001). The relationship between SSFP and FGRE measures were linear and highly correlated (P < 0.001) for both left ventricular end diastolic and end systolic volumes (r(2) = 0.90 vs. 0.91, respectively). We determined linear regression models to estimate the SSFP values based on the FGRE measures. Slope (intercept) for ejection fraction, stroke volume, and cardiac output were 0.99 (-2.79), 0.77 (17.5), and 0.76 (1.29), respectively. CONCLUSION: Linear relationships exist for key LV function parameters when comparing SSFP and FGRE cine MRI. These results indicate that existing databases and normal values for FGRE LV function may be converted to corresponding LV function values for SSFP MRI.     

Defective myocardial blood flow and altered function of the left ventricle in type 2 diabetic rats: a noninvasive in vivo study using perfusion and cine magnetic resonance imaging

OBJECTIVE: In type 2 diabetes mellitus, cardiovascular complications are related to microvascular abnormalities. In this work, we aimed at characterizing in vivo myocardial blood flow and left ventricular function of the Goto-Kakizaki (GK) rat as a nonobese model of type 2 diabetes. MATERIALS AND METHODS: We performed arterial spin labeling magnetic resonance imaging (MRI) for myocardial blood flow quantification and cine MRI for functional evaluation in free-breathing isoflurane-anesthetized animals. RESULTS: Myocardial blood flow was altered in adult female GK rats compared with age-matched female Wistar rats (4.7 +/- 1.6 vs. 7.1 +/- 1.2 mL/g/min respectively, P = 0.0022). Ejection fraction was decreased in GK compared with Wistar rats (64 +/- 7 vs. 78 +/- 8% respectively, P <0.005), mainly as a result of a loss in left ventricular longitudinal contraction. CONCLUSIONS: Adult female GK rats have defective myocardial blood flow associated with altered left ventricular function. This multiparametric MRI approach in the GK rat is of particular interest for the study of type 2 diabetic cardiomyopathy.     

Assessment of systolic thickening with thallium-201 ECG-gated single-photon emission computed tomography: a parameter for local left ventricular function

We measured left ventricular (LV) systolic thickening expressed as a systolic thickening ratio in 28 patients, using 201Tl ECG-gated SPECT. Five normals, 15 patients with prior myocardial infarction, 5 with hypertrophic cardiomyopathy, and 3 with dilated cardiomyopathy were studied. The systolic thickening ratio was calculated as [(end-systolic--end-diastolic pixel counts) divided by end-diastolic pixel counts], using the circumferential profile technique of both end-diastolic and end-systolic short axial images. Functional images of the systolic thickening ratio were also displayed with the "bull's-eye" method. The mean systolic thickening ratio thus calculated were as follows: normals, 0.53 +/- 0.05 (mean +/- 1 s.d.); non-transmural prior myocardial infarction, 0.33 +/- 0.09; transmural prior myocardial infarction, 0.14 +/- 0.05; hypertrophic cardiomyopathy in relatively nonhypertrophied areas, 0.56 +/- 0.11; hypertrophic cardiomyopathy in hypertrophied areas, 0.23 +/- 0.07; and dilated cardiomyopathy, 0.19 +/- 0.02. The systolic thickening ratio analysis by gated thallium SPECT offers a unique approach for assessing LV function.     

Dual breath-hold magnetic resonance cine evaluation of global and regional cardiac function

The purpose of our study was to evaluate the accuracy of a multislice cine magnetic resonance imaging (MRI) technique with parallel imaging in regard to global and regional left ventricular function. Forty-two individuals underwent cine MRI on a 1.5-tesla scanner. Cine MRI used a steady-state free precession technique and was performed as a single-slice technique (nonTSENSE cine) and an accelerated multislice technique (TSENSE cine) with five slices per breath-hold. End diastolic volume (EDV), end systolic volume (ESV), and ejection fraction (EF) were evaluated for all data sets and in regard to regional wall motion and regional wall motion analysis, and quantitative regional wall thickness and systolic thickening were also assessed. EDV, ESV, and EF based on TSENSE cine showed excellent correlation to the nonTSENSE cine approach (all r²=0.99, P<0.001). While EDV evaluations showed a small underestimation for TSENSE cine, ESV and EF showed accurate results compared with nonTSENSE cine. Both readers showed good agreement (κ=0.72) in regional wall motion assessment comparing both techniques. Data acquisition for the multislice approach was significantly shorter (∼75%) that in single-slice cine. We conclude that accurate evaluation of regional wall motion and left ventricular EF is possible using accelerated multislice cine MR with high spatial and temporal resolution.     

中国人心脏房室腔内径及左右心室功能正常参数的MRI研究

目的 使用MRI测量中国正常成人心脏各房室腔内径及心功能参数.方法 共269名正常志愿者,无线矢量心电门控下,采用单次激发半傅立叶快速自旋回波与真实稳态自由进动序列,分别获得标准心脏各长轴及短轴切面二维体层及电影图像.由2名医师独立分析MRI,分别测量心脏各房室腔径线及心功能后处理分析,获得包括射血分数(EF)、舒张末容积(EDV)、收缩末容积( ESV)及心肌质量(CM)等心功能参数.男性与女性相对应参数做非配对的t检验.结果 所有志愿者均完成MR扫描,平均扫描时间(15 ±3) min.心脏各房室腔主要参数为:左心房前后径(2.87±0.77) cm,右心房径(垂直于房间隔,3.61 ±0.57)cm,左心室舒张末横径(4.97±0.52) cm,右心室舒张末横径(2.65±0.48) cm,心功能主要参数为:左心室EF (60.62±7.08)％、EDV( 128.27±32.16) ml、ESV(46.02±15.72) ml、CM( 82.97±24.03)g;右心室EF (47.73±6.50)％、EDV(115.37±26.71) ml、ESV(67.7±21.07) ml、CM(48.24±13.42)g.除左心室ESV(P =0.144)、EDV指数(P=0.714)、ESV指数(P =0.113)、心脏指数(P=0.199)及右心室EF值(P=0.296)和ESV指数(P =0.093)男女差异无统计学意义外,其余各指标性别间差异均有统计学意义(P＜0.01).结论 MRI以其高度的可重复性可获得正常中国人心脏形态与功能信息.