Self-Navigated Multi-Contrast And Quantitative Whole Heart 3D Magnetic Resonance Imaging

尽管在预防和诊断和治疗方面有所改进，但心血管疾病(CVD)仍然是全球主要的单一死亡原因。心脑血管疾病死亡的两个主要原因是斑块破裂引起的突然冠状动脉血栓形成和随后的血栓形成，以及由于不利的心肌重构和随后的心肌梗死扩大而导致的心力衰竭。目前的成像技术对冠状动脉粥样硬化的检测和对不良心肌重构的预测仍然具有挑战性。虽然X线冠状动脉造影术是检测冠状动脉狭窄的金标准，但它在冠状动脉斑块的检测和定性方面的价值有限。多层螺旋CT(MSCT)是一种很好的无创检测冠状动脉狭窄的方法，并具有一定的显示和表征冠状动脉斑块的能力，但其诊断应用仅限于无冠状动脉钙化的患者。正电子断层扫描(PET)对心肌灌注和存活评估具有良好的诊断敏感性，最近也被证明具有显示冠状动脉斑块的潜力，但存在空间分辨率低和辐射暴露的问题，并未得到广泛应用。超声心动图是临床评价左心功能和室壁运动异常的金标准。它价格便宜，使用方便，但严重依赖于运营商。由于上述限制，有必要开发一种替代的、非侵入性的成像测试，允许在不受上述限制的情况下进行全面的心脏评估。根据磁共振学会(SCMR)专家的共识声明，磁共振成像(MRI)因其出色的软组织对比度、高空间分辨率和无电离辐射而被认为是评估心脏解剖、左心室(LF)功能(电影-MRI)、心肌存活(LGE-MRI)和灌注(MR-灌注)的金标准。最近的临床研究也证明了它在定量心肌组织定征(T1和T2松弛时间图)以及区分健康和病变组织的能力方面的有效性。然而，当前MRI采集方案的一个关键限制是所有成像序列(例如电影、LGE、T1和T2映射、冠状动脉MR血管成像(MRA)等)。在不同的几何方向、在不同的屏气位置或使用时间效率低的导航器跟踪方法顺序地获取。这带来了几个挑战：(1)放射技师需要高专业知识来执行复杂的检查，(2)患者必须进行多个(&gt；30)屏气，这对患病患者来说可能是非常具有挑战性的，(3)检查持续时间长，导致操作成本高，(4)由于屏气位置、扫描几何和非各向同性空间分辨率的不同，数据融合困难。我们假设，基于图像的呼吸自主导航与图像加速技术相结合将解决上述挑战，并有助于提高自由呼吸(无屏气)三维(3D)多对比定量全心心脏MRI的可靠性和图像质量。建议的方法将使非侵入性全面心脏检查能够改善患者体验、更高的诊断收益率和更高的成本效益，从而改善NHS白皮书概述的心血管疾病的治疗和结果。

Cardiovascular disease (CVD) remains the leading single cause of death worldwide despite improvements in prevention and advances in diagnosis and treatment. The two major causes for CVD death are sudden coronary atherothrombosis due to plaque rupture and subsequent thrombus formation and heart failure following myocardial infarction (MI) due to adverse myocardial remodeling and subsequent infarct expansion. Detection of coronary atherosclerosis and prediction of adverse myocardial remodeling remain challenging with current imaging techniques. While x-ray coronary angiography is the gold standard for the detection of coronary stenosis it has limited value for the detection and characterization of coronary plaque. Multislice computed tomography (MSCT) is an excellent non-invasive alternative for the detection of coronary stenosis and has some ability to visualize and characterize coronary plaque but its diagnostic use is limited to patients without coronary calcification. Positron electron tomography (PET) has good diagnostic sensitivity for myocardial perfusion and viability assessment and recently also has been shown to have potential for coronary plaque visualization but suffers from low spatial resolution and radiation exposure and is not widely available. Echocardiography is the clinical gold standard for the assessment of left ventricular function and wall motion abnormalities. It is cheap and easy to use but is heavily operator dependent. Due to the above limitations there is a need for the development of an alternative and non-invasive imaging test that allows for comprehensive cardiac assessment without the above restrictions. Magnetic resonance imaging (MRI) is considered the gold standard for the assessment of cardiac anatomy, left ventricular (LF) function (CINE-MRI), myocardial viability (LGE-MRI) and perfusion (MR-perfusion) due to its excellent soft tissue contrast, high spatial resolution and lack of ionizing radiation according to a Society for Magnetic Resonance (SCMR) expert consensus statement. Recent clinical research studies also have demonstrated its usefulness for quantitative myocardial tissue characterization (T1 and T2 relaxation time mapping) and its ability to differentiate between healthy and diseased tissue. However, a key limitation of the current MRI acquisition scheme is that all imaging sequences (e.g. CINE, LGE, T1 and T2 mapping, coronary MR angiography (MRA), etc.) are acquired sequentially, in different geometric orientations, at different breath-hold positions or using time inefficient navigator gating methods. This imposes several challenges: (1) radiographers need high expertise to perform the complex examination, (2) patients have to perform multiple (>30) breathholds which can be very challenging in sick patients, (3) the duration of the examination is long leading to high operational costs and (4) data fusion is difficult because of the different breathhold positions, scan geometries and non-isotropic spatial resolution. We hypothesize that image based respiratory self-navigation combined with image acceleration techniques will address the above challenges and allow improving the reliability and image quality of free-breathing (no breathholds) three-dimensional (3D) multi-contrast quantitative whole heart cardiac MRI. The proposed approach will enable non-invasive comprehensive cardiac examination with improved patient experience, higher diagnostic yield and improved cost effectiveness thereby improving the treatment and outcome of cardiovascular disease as outlined by the NHS white paper.