钆延迟强化联合纵向弛豫时间定量成像评估心肌淀粉样变性的价值

Late gadolinium enhancement and T1 mapping for the diagnosis of cardiac amyloidosis

目的探讨钆延迟强化(LGE)联合纵向弛豫时间定量成像(T1 mapping)对心肌淀粉样变性的诊断价值.方法选择2018年5月至2019年3月在天津市第一中心医院通过肾活检确诊的轻链型(AL)淀粉样变性而发生急性心力衰竭(心衰)怀疑累及心脏的心肌淀粉样变性患者9例,以及同一时段检查的非梗阻性肥厚型心肌病患者14例,以同期12例健康体检者作为对照.用飞利浦Ingenia 3.0 T进行心脏检查,平扫包括电影序列、T2加权成像(T2WI)、增强前T1 mapping,增强检查包括首过灌注、延迟增强及增强后T1 mapping;对比剂用钆喷酸葡胺注射液,首过灌注0.1 mL/kg,以相同速度追加生理盐水20 mL,延迟7 min开始扫描延迟增强序列,包括4层2腔心位和4腔心位.观察LGE联合T1 mapping的心脏磁共振成像(CMRI)检查结果,包括心功能指标〔左心室舒张期末容积(LVEDV)、左心室收缩期末容积(LVESV)、左室射血分数(LVEF)、瓣膜反流〕、心脏形态学指标〔包括左室壁厚度、左心室质量(LVM)〕、心肌组织学特点及心肌标志物N末端脑钠肽前体(NT-proBNP)和伴随征像(包括心包积液、胸腔积液).结果心肌淀粉样变性患者的CMRI影像学可以表现为左心室斑片状强化、心内膜下条状强化、心内膜下弥漫强化,有时可延伸到心外膜及不典型的异常延迟强化.9例(100%)心肌淀粉样变性患者均有延迟强化,其中3例为左室壁斑片状强化,3例为左心室心内膜弥漫强化,2例为局限性心内膜下强化,1例为不典型异常延迟强化.心肌淀粉样变性组增强前T1值明显高于健康对照组和肥厚型心肌病组(ms:1497.3±22.0比1273.3±30.1、1329.3±42.6,均P<0.05);增强后T1值低于健康对照组和肥厚型心肌病组,但差异无统计学意义(ms:476.7±44.2比516.1±41.5、569.9±12.3,均P>0.05).有3例心肌淀粉样变性患者化疗1个周期后复查CMRI平扫的增强前T1 mapping,显示化疗后T1值与化疗前无明显差异(ms:1484.8±6.5比1497.3±22.0,P=0.11).结论一站式CMRI检查可以提高心肌淀粉样变性的诊断效力,LGE可以显示心肌瘢痕及纤维化,T1 mapping对心肌水肿及弥漫纤维化很敏感,LGE与T1 mapping联合可提高诊断准确性,对诊断和随访患者治疗很有意义.

Objective To explore the role of late gadolinium enhancement(LGE)and T1 mapping for detection of cardiac amyloidosis.Methods Nine cases of cardiac amyloidosis who had diagnosed by renal biopsy diagnosed type light-chain(AL)amyloidosis and acute heart failure suspected involvement of the heart in Tianjin First Central Hospital from May 2018 to March 2019 were enrolled,and at the same time 14 cases of non-obstructive hypertrophic cardiomyopathy patients,12 cases of healthy physical examination at the same period were enrolled as the control.All patients underwent Philips 3.0-T including plain scan as cine,T2WI,native T1 mapping and enhanced scan as perfusion,LGE imaging,post T1 mapping.For LGE cardiac magnetic resonance imaging(CMRI),a bolus of 0.1 mL/kg of gadolinium-based contrast followed by a 20 mL saline flush was administered.After a 7-minutes delay,ECG-gated images were acquired in 3 long-axis and a stack of short-axis slices identical to those of cine images using a breath-hold gradient recalled echo phase-sensitive or magnitude only inversion recovery sequence.LGE and T1 mapping CMRI observation,including cardiac function index[left ventricle end-diastolic volume(LVEDV),left ventricle end-systolic volume(LVESV),left ventricular ejection fraction(LVEF),valvular regurgitation],cardiac morphological index[including left ventricular wall thickness,left ventricular weight(LVM)],myocardial histological characteristics and markers N-terminal pro-brain natriuretic peptide(NT-proBNP)and accompanying signs(including pericardial effusion,pleural effusion)were performed.Results The predominant LGE pattern in amyloidosis was diffuse left ventricular sub endocardial enhancement(3/9),diffuse in left ventricular wall enhancement(3/9),and transmural delayed enhancement in left ventricular(2/9)and non-typical delayed enhancement(1/9).Myocardial T1 was significantly elevated in cardiac AL amyloidosis patients compared to normal subjects and hypertrophic cardiomyopathy(ms:1497.3±22.0 vs.1273.3±30.1,1329.3±42.6,both P<0.05).Myocardial T1 was increased in AL amyloid before LGE.A post-contrast myocardial T1 was significantly elevated in cardiac AL amyloidosis patients compared to normal subjects and hypertrophic cardiomyopathy(ms:476.7±44.2 vs.516.1±41.5,569.9±12.3,both P>0.05).Three of 9 amyloidosis patients with review images showing T1 value and cardiac function was no significantly different with the first check(ms:1484.8±6.5 vs.1497.3±22.0,P=0.11).Conclusions One-stop CMRI can improve the diagnosis of cardiac amyloidosis,LGE can display the myocardial scarring and fibrosis,and T1 mapping is sensitive to myocardial edema and diffuse fibrosis.LGE and T1 mapping can improve the diagnostic accuracy,which is very meaningful for diagnosis and follow-up of patients.