共查询到20条相似文献,搜索用时 15 毫秒
1.
可挽救心肌或心肌挽救指数对急性心肌梗死患者治疗策略选择、疗效评价、预后判断有重要价值。计算可挽救心肌的前提是准确评估心肌危险区和梗死核心。心血管磁共振(CMR)能较准确评估危险区及梗死核心。本文将对CMR常用的扫描技术(T2WI、灌注成像、延迟强化等)及新的扫描技术(T2mapping、T1mapping、T1ρ等)评估急性心肌梗死危险区和梗死核心的机制、优势、目前存在问题及研究趋势进行综述。 相似文献
2.
Steen Fjord Pedersen Samuel A Thrys?e Michael P Robich William P Paaske Steffen Ringgaard Hans Erik B?tker Esben S S Hansen Won Yong Kim 《Journal of cardiovascular magnetic resonance》2012,14(1):59
Background
Intramyocardialhemorrhage (IMH) reflects severe reperfusion injury in acute myocardial infarction. Non-invasive detection of IMH by cardiovascular magnetic resonance (CMR) may serve as a surrogate marker to evaluate the effect of preventive measures to reduce reperfusion injury and hence provide additional prognostic information. We sought to investigate whether IMH could be detected by CMR exploiting the T1 shortening effect of methemoglobin in an experimental model of acute myocardial infarction. The results were compared to T2-weighthed short tau inversion recovery (T2-STIR), and T2*-weighted(T2*W) sequences.Methods and results
IMH was induced in ten 40 kg pigs by 50-min balloon occlusion of the mid LAD followed by reperfusion. Between 4–9 days (average 4.8) post-injury, the left ventricular myocardium was assessed by T1-weigthed Inversion Recovery(T1W-IR), T2-STIR, and T2*Wsequences. All CMR images were matched to histopathology and compared with the area of IMH. The difference between the size of the IMH area detected on T1W-IR images and pathology was −1.6 ± 11.3% (limits of agreement, -24%–21%), for the T2*W images the difference was −0.1 ± 18.3% (limitsof agreement, -36.8%–36.6%), and for T2-STIR the difference was 8.0 ± 15.5% (limits of agreement, -23%–39%). By T1W IR the diagnostic sensitivity of IMH was 90% and specificity 70%, for T2*W imaging the sensitivity was 70% and specificity 50%, and for T2-STIR sensitivity for imaging IMH was 50% and specificity 60%.Conclusion
T1-weigthednon-contrast enhanced CMR detects IMH with high sensitivity and specificity and may become a diagnostic tool for detection of IMH in patients with myocardial infarction. 相似文献3.
《Expert review of cardiovascular therapy》2013,11(12):1455-1464
Cardiovascular magnetic resonance is an important tool for patient care and is the best test for myocardial structure and function. Ischemia and scar imaging also provide key insights and focus attention on heart muscle – the site of most cardiac diseases. New ways of measuring abnormal muscle have been developed, including T1 mapping. Abnormal signal can be distinguished either without contrast (native T1), or post-contrast (extracellular volume measurement). Large changes occur in rare diseases (cardiac amyloidosis, Anderson-Fabry disease and iron overload) even at an early stage, while more subtle changes are seen in diffuse fibrosis where a robust test would be of major impact. This review presents the potential future clinical utility of T1 mapping – a technology to watch. 相似文献
4.
5.
目的运用3.0 T MR扩散张量成像(diffusion tensor imaging,DTI)对心肌梗死后梗死区、边缘区及非梗死区的心肌重构进行动态监测,以发现心室重构的规律性和异质性。材料与方法选用50只成年雄性兔,分为正常组(5只),假手术组(5只)和实验组(40只),实验组根据心肌梗死术后1、2、4、8周及16周分为5个亚组(8只)。通过结扎冠状动脉左室支,建立兔心肌梗死模型,术后死亡7只,实验组存活33只。将离体兔心脏标本进行3.0 T DTI扫描,测量梗死区、边缘区和非梗死区的各向异性分数(fractional anisotropy,FA)值和平均扩散系数(mean diffusion coefficient,MD)值,动态观察DTI指标的演变过程。结果 (1)梗死区和边缘区的FA值在术后第1周时均显著下降,之后下降较缓慢,均在第4周时达最低。之后梗死区FA基本稳定,而边缘区FA小幅度升高至8周时稳定。(2)在术后4周内,梗死区MD呈迅速明显上升趋势而边缘区MD渐进性轻度升高,两者均是在第4周时达高峰。之后梗死区MD基本稳定至8周,在第16周时有小幅度下降。边缘区MD在第8周时轻度下降,之后稳定。结论心肌梗死后心室重构是复杂且动态变化的过程,在心梗后第1周内,梗死区和边缘区组织重构最为迅速且明显,在第4周时重构达高峰,即组织破坏最为严重,心梗长达8周后重构基本稳定。DTI能够揭示心室不同区域重构的规律性,对指导临床治疗有着重要意义。 相似文献
6.
Darius Dabir Nicholas Child Ashwin Kalra Toby Rogers Rolf Gebker Andrew Jabbour Sven Plein Chung-Yao Yu James Otton Ananth Kidambi Adam McDiarmid David Broadbent David M Higgins Bernhard Schnackenburg Lucy Foote Ciara Cummins Eike Nagel Valentina O Puntmann 《Journal of cardiovascular magnetic resonance》2014,16(1)
Background
T1 mapping is a robust and highly reproducible application to quantify myocardial relaxation of longitudinal magnetisation. Available T1 mapping methods are presently site and vendor specific, with variable accuracy and precision of T1 values between the systems and sequences. We assessed the transferability of a T1 mapping method and determined the reference values of healthy human myocardium in a multicenter setting.Methods
Healthy subjects (n = 102; mean age 41 years (range 17–83), male, n = 53 (52%)), with no previous medical history, and normotensive low risk subjects (n=113) referred for clinical cardiovascular magnetic resonance (CMR) were examined. Further inclusion criteria for all were absence of regular medication and subsequently normal findings of routine CMR. All subjects underwent T1 mapping using a uniform imaging set-up (modified Look- Locker inversion recovery, MOLLI, using scheme 3(3)3(3)5)) on 1.5 Tesla (T) and 3 T Philips scanners. Native T1-maps were acquired in a single midventricular short axis slice and repeated 20 minutes following gadobutrol. Reference values were obtained for native T1 and gadolinium-based partition coefficients, λ and extracellular volume fraction (ECV) in a core lab using standardized postprocessing.Results
In healthy controls, mean native T1 values were 950 ± 21 msec at 1.5 T and 1052 ± 23 at 3 T. λ and ECV values were 0.44 ± 0.06 and 0.25 ± 0.04 at 1.5 T, and 0.44 ± 0.07 and 0.26 ± 0.04 at 3 T, respectively. There were no significant differences between healthy controls and low risk subjects in routine CMR parameters and T1 values. The entire cohort showed no correlation between age, gender and native T1. Cross-center comparisons of mean values showed no significant difference for any of the T1 indices at any field strength. There were considerable regional differences in segmental T1 values. λ and ECV were found to be dose dependent. There was excellent inter- and intraobserver reproducibility for measurement of native septal T1.Conclusion
We show transferability for a unifying T1 mapping methodology in a multicenter setting. We provide reference ranges for T1 values in healthy human myocardium, which can be applied across participating sites.Electronic supplementary material
The online version of this article (doi:10.1186/s12968-014-0069-x) contains supplementary material, which is available to authorized users. 相似文献7.
Bernard P Paelinck Christiaan J Vrints Jeroen J Bax Johan M Bosmans Albert de Roos Hildo J Lamb 《Journal of cardiovascular magnetic resonance》2007,9(6):877-882
PURPOSE: To investigate regional diastolic and systolic function using tissue cardiovascular magnetic resonance (CMR), early after transmural myocardial infarction of the inferior wall due to single proximal right coronary artery disease. MATERIALS AND METHODS: Velocity encoded CMR was used to measure early diastolic transmitral flow velocity (E), and regional, longitudinal, myocardial systolic (Sa) and early diastolic (Ea) velocities (tissue CMR) in 15 patients with a recent transmural inferior myocardial infarction and in 15 age and LV-mass index matched control subjects. An unpaired two-tailed t test was used to assess significance of continuous variables. RESULTS: Global systolic (ejection fraction 46 +/- 7% versus 57 +/- 4%, p = 0.000052) and global diastolic LV function (average Ea of infarcted or inferior, remote or anterior, adjacent or septal and lateral myocardium 6.8 +/- 1.7 cm/s versus 10.4 +/- 1.5 cm/s, p = 0.0000012) were impaired in patients as compared to controls. Regional systolic and diastolic LV velocities were impaired in infarcted and adjacent tissue in patients. However, in remote or anterior tissue, systolic velocities were preserved (Sa 6.6 +/- 2.0 cm/s versus 6.8 +/- 1.4 cm/s, p = 0.70), but diastolic velocities were impaired in patients as compared to controls (Ea 7.2 +/- 2.3 cm/s versus 10.2 +/- 2.5 cm/s, p = 0.0026). CONCLUSIONS: Regional diastolic velocities early after inferior myocardial infarction are impaired in the infarcted, adjacent and remote tissue, but regional systolic velocities are preserved in remote tissue. 相似文献
8.
Gender differences in contrast-enhanced magnetic resonance imaging after acute myocardial infarction
Birgit Langhans Tareq Ibrahim Jörg Hausleiter Carolin Sonne Stefan Martinoff Albert Schömig Martin Hadamitzky 《The international journal of cardiovascular imaging》2013,29(3):643-650
Besides different risk profiles for cardiovascular events in men and women, several studies reported gender differences in mortality after acute myocardial infarction (AMI). As infarct size has been shown to correlate with mortality, it is widely accepted as surrogate marker for clinical outcome. Currently, cardiovascular imaging studies covering the issue of gender differences are rare. As magnetic resonance scar characterization parameters are emerging as additional prognostic factors after acute myocardial infarction, we sought to evaluate gender differences in CMR infarct characteristics in patients after acute myocardial infarction. We prospectively analyzed patients (n = 448) with AMI and primary angioplasty, who underwent contrast enhanced cardiac magnetic resonance (CMR) imaging on a 1.5 T scanner in median 5 [Galatius-Jensen et al. in BMJ 313(7050):137–140, (1996), Burns et al. in J Am Coll Cardiol 39(1):30–36, (2002)] days after the acute event. CMR scar size was measured 15 min after gadolinium injection. In addition presence and extent of microvascular obstruction (MVO) was assessed. A matched pair analysis was performed in order to exclude confounding by gender related co-morbidities and gender differences in established clinical risk factors. Matching process according to clinical risk defined by GRACE score resulted in 93 mixed gender couples. Women were significantly older than men (64.4 ± 11.9 vs. 60.5 ± 12.3, p = 0.03) and presented with a significantly better ejection fraction before angioplasty (48.9 ± 8.4 vs. 46.2 ± 8.9, p = 0.04). Infarct size did not differ significantly between women and men (13.5 ± 10.7 vs. 15.1 ± 11.8, p = 0.32). Size of MVO was significantly smaller in women than in men (0.48 ± 1.3 vs. 1.2 ± 3.0, p = 0.03). Comparing scar characterization between women and men with similar risk profiles revealed no gender differences in scar size. Size of MVO, however, was significantly smaller in women and might reflect better cardioprotective mechanisms in women. Whether these changes have prognostic implications has to be tested on a larger patient population. 相似文献
9.
Laura C. Saunders Chris S. Johns Neil J. Stewart Charlotte J. E. Oram David A. Capener Valentina O. Puntmann Charlie A. Elliot Robin C. Condliffe David G. Kiely Martin J. Graves Jim M. Wild Andy J. Swift 《Journal of cardiovascular magnetic resonance》2018,20(1):78
Background
Native T1 may be a sensitive, contrast-free, non-invasive cardiovascular magnetic resonance (CMR) marker of myocardial tissue changes in patients with pulmonary artery hypertension. However, the diagnostic and prognostic value of native T1 mapping in this patient group has not been fully explored. The aim of this work was to determine whether elevation of native T1 in myocardial tissue in pulmonary hypertension: (a) varies according to pulmonary hypertension subtype; (b) has prognostic value and (c) is associated with ventricular function and interaction.Methods
Data were retrospectively collected from a total of 490 consecutive patients during their clinical 1.5 T CMR assessment at a pulmonary hypertension referral centre in 2015. Three hundred sixty-nine patients had pulmonary hypertension [58?±?15 years; 66% female], an additional 39 had pulmonary hypertension due to left heart disease [68?±?13 years; 60% female], 82 patients did not have pulmonary hypertension [55?±?18; 68% female]. Twenty five healthy subjects were also recruited [58 ±4 years); 51% female]. T1 mapping was performed with a MOdified Look-Locker Inversion Recovery (MOLLI) sequence. T1 prognostic value in patients with pulmonary arterial hypertension was assessed using multivariate Cox proportional hazards regression analysis.Results
Patients with pulmonary artery hypertension had elevated T1 in the right ventricular (RV) insertion point (pulmonary hypertension patients: T1?=?1060?±?90 ms; No pulmonary hypertension patients: T1?=?1020?±?80 ms p <?0.001; healthy subjects T1?=?940?±?50 ms p <?0.001) with no significant difference between the major pulmonary hypertension subtypes. The RV insertion point was the most successful T1 region for discriminating patients with pulmonary hypertension from healthy subjects (area under the curve?=?0.863) however it could not accurately discriminate between patients with and without pulmonary hypertension (area under the curve?=?0.654). T1 metrics did not contribute to prediction of overall mortality (septal: p =?0.552; RV insertion point: p =?0.688; left ventricular free wall: p =?0.258). Systolic interventricular septal angle was a significant predictor of T1 in patients with pulmonary hypertension (p <?0.001).Conclusions
Elevated myocardial native T1 was found to a similar extent in pulmonary hypertension patient subgroups and is independently associated with increased interventricular septal angle. Native T1 mapping may not be of additive value in the diagnostic or prognostic evaluation of patients with pulmonary artery hypertension.10.
Gert Klug Agnes Mayr Sonja Schenk Regina Esterhammer Michael Schocke Michael Nocker Werner Jaschke Otmar Pachinger Bernhard Metzler 《Journal of cardiovascular magnetic resonance》2012,14(1):46
Background
Early and late microvascular obstruction (MVO) assessed by cardiovascular magnetic resonance (CMR) are prognostic markers for short-term clinical endpoints after acute ST-elevation myocardial infarction (STEMI). However, there is a lack of studies with long-term follow-up periods (>24 months).Methods
STEMI patients reperfused by primary angioplasty (n = 129) underwent MRI at a median of 2 days after the index event. Early MVO was determined on dynamic Gd first-pass images directly after the administration of 0.1 mmol/kg bodyweight Gd-based contrast agent. Furthermore, ejection fraction (EF, %), left ventricular myocardial mass (LVMM) and total infarct size (% of LVMM) were determined with CMR. Clinical follow-up was conducted after a median of 52 months. The primary endpoint was defined as a composite of death, myocardial re-infarction, stroke, repeat revascularization, recurrence of ischemic symptoms, atrial fibrillation, congestive heart failure and hospitalization.Results
Follow-up was completed by 107 patients. 63 pre-defined events occurred during follow-up. Initially, 74 patients showed early MVO. Patients with early MVO had larger infarcts (mean: 24.9 g vs. 15.5 g, p = 0.002) and a lower EF (mean: 39% vs. 46%, p = 0.006). The primary endpoint occurred in 66.2% of patients with MVO and in 42.4% of patients without MVO (p < 0.05). The presence of early MVO was associated with a reduced event-free survival (log-rank p < 0.05). Early MVO was identified as the strongest independent predictor for the occurrence of the primary endpoint in the multivariable Cox regression analysis adjusting for age, ejection fraction and infarct size (hazard ratio: 2.79, 95%-CI 1.25-6.25, p = 0.012).Conclusion
Early MVO, as assessed by first-pass CMR, is an independent long-term prognosticator for morbidity after AMI. 相似文献11.
Christopher Nguyen Zhaoyang Fan Yibin Xie James Dawkins Eleni Tseliou Xiaoming Bi Behzad Sharif Rohan Dharmakumar Eduardo Marbán Debiao Li 《Journal of cardiovascular magnetic resonance》2014,16(1)
Background
Despite the established role of late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) in characterizing chronic myocardial infarction (MI), a significant portion of chronic MI patients are contraindicative for the use of contrast agents. One promising alternative contrast free technique is diffusion weighted CMR (dwCMR), which has been shown ex vivo to be sensitive to myocardial fibrosis. We used a recently developed in vivo dwCMR in chronic MI pigs to compare apparent diffusion coefficient (ADC) maps with LGE imaging for infarct characterization.Methods
In eleven mini pigs, chronic MI was induced by complete occlusion of the left anterior descending artery for 150 minutes. LGE, cine, and dwCMR imaging was performed 8 weeks post MI. ADC maps were derived from three orthogonal diffusion directions (b = 400 s/mm2) and one non-diffusion weighted image. Two semi-automatic infarct classification methods, threshold and full width half max (FWHM), were performed in both LGE and ADC maps. Regional wall motion (RWM) analysis was performed and compared to ADC maps to determine if any observed ADC change was significantly influenced by bulk motion.Results
ADC of chronic MI territories was significantly increased (threshold: 2.4 ± 0.3 μm2/ms, FWHM: 2.4 ± 0.2 μm2/ms) compared to remote myocardium (1.4 ± 0.3 μm2/ms). RWM was significantly reduced (threshold: 1.0 ± 0.4 mm, FWHM: 0.9 ± 0.4 mm) in infarcted regions delineated by ADC compared to remote myocardium (8.3 ± 0.1 mm). ADC-derived infarct volume and location had excellent agreement with LGE. Both LGE and ADC were in complete agreement when identifying transmural infarcts. Additionally, ADC was able to detect LGE-delineated infarcted segments with high sensitivity, specificity, PPV, and NPV. (threshold: 0.88, 0.93, 0.87, and 0.94, FWHM: 0.98, 0.97, 0.93, and 0.99, respectively).Conclusions
In vivo diffusion weighted CMR has potential as a contrast free alternative for LGE in characterizing chronic MI. 相似文献12.
13.
14.
背景:心脏磁共振延迟成像被认为是极有前景的无创性判断心肌存活状态的影像检查手段。目前常用的对比剂Gd-DTPA存在过高或过低评价存活心肌和不可逆性梗死心肌,而坏死亲和性对比剂ECIII-600可以准确地反映坏死心肌的面积。目的:对比冠脉内注射坏死亲和性对比剂在猪再灌注急性心肌梗死存活心肌诊断中的应用价值。方法:三四个月龄普通家猪12头,建立急性再灌注心肌梗死动物模型,分别冠脉内注射0.1mmol/kgGd-DTPA或0.005mmol/kgECIII-600。胸导R波触发心电门控,T1加权FAST序列,短轴面延迟强化扫描成像。扫描结束后沿短轴面将心脏切成6mm断面行氯化三苯基四氮唑染色和光镜检查。比较相应层面的MRI延迟强化区和氯化三苯基四氮唑染色所示梗死区的关系。结果与结论:注射Gd-DTPA的延迟成像10min时强化区面积与氯化三苯基四氮唑染色相比过高估计梗死心肌面积约21%,30min时强化区面积与氯化三苯基四氮唑染色结果一致,之后则过低估计坏死心肌的面积;注射ECIII-600的延迟磁共振成像在坏死区显示强烈而持续的对比增强,强化区面积与氯化三苯基四氮唑染色所示心肌梗死面积一致。说明ECIII-600增强磁共振延迟成像可以准确反映急性心肌梗死面积。Gd-DTPA评价心肌梗死面积不稳定,观察时间窗短,心脏磁共振成像应在对比剂注射后1h以内完成。 相似文献
15.
背景:心脏磁共振延迟成像被认为是极有前景的无创性判断心肌存活状态的影像检查手段。目前常用的对比剂Gd-DTPA存在过高或过低评价存活心肌和不可逆性梗死心肌,而坏死亲和性对比剂ECIII-600可以准确地反映坏死心肌的面积。目的:对比冠脉内注射坏死亲和性对比剂在猪再灌注急性心肌梗死存活心肌诊断中的应用价值。方法:三四个月龄普通家猪12头,建立急性再灌注心肌梗死动物模型,分别冠脉内注射0.1mmol/kgGd-DTPA或0.005mmol/kgECIII-600。胸导R波触发心电门控,T1加权FAST序列,短轴面延迟强化扫描成像。扫描结束后沿短轴面将心脏切成6mm断面行氯化三苯基四氮唑染色和光镜检查。比较相应层面的MRI延迟强化区和氯化三苯基四氮唑染色所示梗死区的关系。结果与结论:注射Gd-DTPA的延迟成像10min时强化区面积与氯化三苯基四氮唑染色相比过高估计梗死心肌面积约21%,30min时强化区面积与氯化三苯基四氮唑染色结果一致,之后则过低估计坏死心肌的面积;注射ECIII-600的延迟磁共振成像在坏死区显示强烈而持续的对比增强,强化区面积与氯化三苯基四氮唑染色所示心肌梗死面积一致。说明ECIII-600增强磁共振延迟成像可以准确反映急性心肌梗死面积。Gd-DTPA评价心肌梗死面积不稳定,观察时间窗短,心脏磁共振成像应在对比剂注射后1h以内完成。 相似文献
16.
Colin J. Yi Eunice Yang Shenghan Lai Neville Gai Chia Liu Songtao Liu Stefan L. Zimmerman João A. C. Lima David A. Bluemke 《The international journal of cardiovascular imaging》2014,30(7):1339-1346
To evaluate long-term changes in diffuse myocardial fibrosis using cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) and T1 mapping. Patients with chronic stable cardiomyopathy and stable clinical status (n = 52) underwent repeat CMR at a 6 month or greater follow up interval and had LGE and left ventricular (LV) T1 mapping CMR. Diffuse myocardial fibrosis (excluding areas of focal myocardial scar) was assessed by post gadolinium myocardial T1 times. Mean baseline age of 52 patients (66 % male) was 35 ± 19 years with a mean interval between CMR examinations of 2.0 ± 0.8 years. CMR parameters, including LV mass and ejection fraction, showed no change at follow-up CMR (p > 0.05). LVT1 times (excluding focal scar) decreased over the study interval (from 468 ± 106 to 434 ± 82 ms, p = 0.049). 38 Patients had no visual LGE?, while 14 were LGE+. For LGE? patients, greater change in LV mass and end systolic volume index were associated with change in T1 time (β = ?2.03 ms/g/m2, p = 0.035 and β = 2.1 ms/mL/m2, p = 0.029, respectively). For LGE+ patients, scar size was stable between CMR1 and CMR2 (10.7 ± 13.8 and 11.5 ± 13.9 g, respectively, p = 0.32). These results suggest that diffuse myocardial fibrosis, as assessed by T1 mapping, progresses over time in patients with chronic stable cardiomyopathy. 相似文献
17.
18.
Sinn Martin R. Lund Gunnar K. Muellerleile Kai Freiwald Eric Saeed Maythem Avanesov Maxim Lenz Alexander Starekova Jitka von Kodolitsch Yskert Blankenberg Stefan Adam Gerhard Tahir Enver 《The international journal of cardiovascular imaging》2021,37(5):1711-1720
The International Journal of Cardiovascular Imaging - To study the long-term prognosis of early pre-discharge and late left ventricular (LV) dilatation in patients with first ST-elevation... 相似文献
19.
Wessel P Brouwer Emma N Baars Tjeerd Germans Karin de Boer Aernout M Beek Jolanda van der Velden Albert C van Rossum Mark BM Hofman 《Journal of cardiovascular magnetic resonance》2014,16(1):28