Department of Medicine, University College London Hospitals National Health Service Trust, The Heart Hospital, 16-18 Westmoreland St, London W1G 8PH, United Kingdom.
Circulation. 2010 Jul 13;122(2):138-44. doi: 10.1161/CIRCULATIONAHA.109.930636. Epub 2010 Jun 28.
Diffuse myocardial fibrosis is a final end point in most cardiac diseases. It is missed by the cardiovascular magnetic resonance (CMR) late gadolinium enhancement technique. Currently, quantifying diffuse myocardial fibrosis requires invasive biopsy, with inherent risk and sampling error. We have developed a robust and noninvasive technique, equilibrium contrast CMR (EQ-CMR) to quantify diffuse fibrosis and have validated it against the current gold standard of surgical myocardial biopsy.
The 3 principles of EQ-CMR are a bolus of extracellular gadolinium contrast followed by continuous infusion to achieve equilibrium; a blood sample to measure blood volume of distribution (1-hematocrit); and CMR to measure pre- and postequilibrium T1 (with heart rate correction). The myocardial volume of distribution is calculated, reflecting diffuse myocardial fibrosis. Clinical validation occurred in patients undergoing aortic valve replacement for aortic stenosis or myectomy in hypertrophic cardiomyopathy (n=18 and n=8, respectively). Surgical biopsies were analyzed for picrosirius red fibrosis quantification on histology. The mean histological fibrosis was 20.5+/-11% in aortic stenosis and 17.1+/-7.4% in hypertrophic cardiomyopathy. EQ-CMR correlated strongly with biopsy histological fibrosis: aortic stenosis, r(2)=0.86, Kendall Tau coefficient (T)=0.71, P<0.001; hypertrophic cardiomyopathy, r(2)=0.62, T=0.52, P=0.08; combined r(2)=0.80, T=0.67, P<0.001.
We have developed and validated a new technique, EQ-CMR, to measure diffuse myocardial fibrosis as an add-on to a standard CMR scan, which allows for the noninvasive quantification of the diffuse fibrosis burden in myocardial diseases.
弥漫性心肌纤维化是大多数心脏疾病的终末结果。心血管磁共振（CMR）晚期钆增强技术会错过该结果。目前，定量弥漫性心肌纤维化需要进行具有潜在风险和取样误差的侵入性活检。我们已经开发出一种强大的非侵入性技术，即平衡对比磁共振（EQ-CMR），以定量弥漫性纤维化，并已将其与手术心肌活检的当前金标准进行了验证。
EQ-CMR 的 3 个原则是：静脉注射细胞外钆对比剂形成的团块，随后进行连续输注以达到平衡；采集血样以测量血容量分布（1-红细胞压积）；CMR 测量平衡前后 T1（需进行心率校正）。计算心肌容量分布，反映弥漫性心肌纤维化。临床验证在因主动脉瓣狭窄而行主动脉瓣置换术或肥厚型心肌病而行心肌切除术的患者中进行（分别为 18 例和 8 例）。对手术活检进行皮尔斯罗辛红纤维化定量分析。主动脉瓣狭窄患者的组织学纤维化平均值为 20.5+/-11%，肥厚型心肌病患者为 17.1+/-7.4%。EQ-CMR 与活检组织学纤维化相关性很强：主动脉瓣狭窄，r(2)=0.86，Kendall Tau 系数（T）=0.71，P<0.001；肥厚型心肌病，r(2)=0.62，T=0.52，P=0.08；联合 r(2)=0.80，T=0.67，P<0.001。
我们已经开发并验证了一种新技术，EQ-CMR，用于测量弥漫性心肌纤维化，作为标准 CMR 扫描的附加项，可实现对心肌疾病弥漫性纤维化负担的无创定量。
