Pixel-wise assessment of cardiovascular magnetic resonance first-pass perfusion using a cardiac phantom mimicking transmural myocardial perfusion gradients.
- 作者列表："Milidonis X","Nazir MS","Schneider T","Capstick M","Drost S","Kok G","Pelevic N","Poelma C","Schaeffter T","Chiribiri A
PURPOSE:Cardiovascular magnetic resonance first-pass perfusion for the pixel-wise detection of coronary artery disease is rapidly becoming the clinical standard, yet no widely available method exists for its assessment and validation. This study introduces a novel phantom capable of generating spatially dependent flow values to enable assessment of new perfusion imaging methods at the pixel level. METHODS:A synthetic multicapillary myocardial phantom mimicking transmural myocardial perfusion gradients was designed and manufactured with high-precision 3D printing. The phantom was used in a stationary flow setup providing reference myocardial perfusion rates and was scanned on a 3T system. Repeated first-pass perfusion MRI for physiological perfusion rates between 1 and 4 mL/g/min was performed using a clinical dual-sequence technique. Fermi function-constrained deconvolution was used to estimate pixel-wise perfusion rate maps. Phase contrast (PC)-MRI was used to obtain velocity measurements that were converted to perfusion rates for validation of reference values and cross-method comparison. The accuracy of pixel-wise maps was assessed against simulated reference maps. RESULTS:PC-MRI indicated excellent reproducibility in perfusion rate (coefficient of variation [CoV] 2.4-3.5%) and correlation with reference values (R2 = 0.985) across the full physiological range. Similar results were found for first-pass perfusion MRI (CoV 3.7-6.2%, R2 = 0.987). Pixel-wise maps indicated a transmural perfusion difference of 28.8-33.7% for PC-MRI and 23.8-37.7% for first-pass perfusion, matching the reference values (30.2-31.4%). CONCLUSION:The unique transmural perfusion pattern in the phantom allows effective pixel-wise assessment of first-pass perfusion acquisition protocols and quantification algorithms before their introduction into routine clinical use.
目的: 心血管磁共振首过灌注用于冠状动脉疾病的像素检测正迅速成为临床标准，但目前还没有广泛可用的评估和验证方法。该研究引入了一种能够产生空间依赖的流量值的新型体模，以使得能够在像素水平上评估新的灌注成像方法。 方法: 采用高精度3D打印技术设计并制作模拟透壁心肌灌注梯度的人工合成多毛细血管心肌体模。在提供参考心肌灌注率的固定流动设置中使用体模，并在3t系统上扫描。使用临床双序列技术对生理灌注速率在1和4 mL/g/min之间的重复首过灌注MRI进行。使用费米函数约束的反卷积来估计像素级灌注速率图。相位对比 (PC)-MRI用于获得速度测量，其被转换为灌注率，用于参考值的验证和交叉方法比较。针对模拟参考图评估像素映射的准确度。 结果: pc-mri显示在整个生理范围内灌注率 (变异系数 [CoV] 2.4-3.5%) 和与参考值的相关性 (R2 = 0.985) 具有优异的再现性。对于首过灌注MRI发现类似的结果 (CoV 3.7-6.2%，R2 = 0.987)。像素映射表明pc-mri的透壁灌注差为28.8-33.7%，首过灌注差为23.8-37.7%，与参考值 (30.2-31.4%) 相匹配。 结论: 体模中独特的透壁灌注模式允许在首过灌注采集协议和量化算法引入常规临床使用之前对其进行有效的像素级评估。
METHODS::We present the case of a 61-year-old woman with a large tumoral infiltration extending from the pelvis throughout the inferior vena cava inferior to the right atrium, protruding into the right ventricle and right ventricular outflow tract. She had been treated 10 years before for low-grade endometrial stromal sarcoma by hysterectomy and adnexectomy followed by hormone- and radio-therapy. Due to cancer recurrence, she underwent peritonectomy, appendectomy, and resection of terminal ileum.
METHODS:AIMS:Significant platelet activation after long stented coronary segments has been associated with periprocedural microvascular impairment and myonecrosis. In long lesions treated either with an everolimus-eluting bioresorbable vascular scaffold (BVS) or an everolimus-eluting stent (EES), we aimed to investigate (a) procedure-related microvascular impairment, and (b) the relationship of platelet activation with microvascular function and related myonecrosis. METHODS AND RESULTS:Patients (n=66) undergoing elective percutaneous coronary intervention (PCI) in long lesions were randomised 1:1 to either BVS or EES. The primary endpoint was the difference between groups in changes of pressure-derived corrected index of microvascular resistance (cIMR) after PCI. Periprocedural myonecrosis was assessed by high-sensitivity cardiac troponin T (hs-cTnT), platelet reactivity by high-sensitivity adenosine diphosphate (hs-ADP)-induced platelet reactivity with the Multiplate Analyzer. Post-dilatation was more frequent in the BVS group, with consequent longer procedure time. A significant difference was observed between the two groups in the primary endpoint of ΔcIMR (p=0.04). hs-ADP was not different between the groups at different time points. hs-cTnT significantly increased after PCI, without difference between the groups. CONCLUSIONS:In long lesions, BVS implantation is associated with significant acute reduction in IMR as compared with EES, with no significant interaction with platelet reactivity or periprocedural myonecrosis.
METHODS:BACKGROUND:Aortopulmonary window is an uncommon congenital heart disease, with untreated cases not surviving beyond childhood. However, very rarely it can present in adult patients with features of pulmonary hypertension. Clinically these patients cannot be differentiated from other more common conditions with left to right shunt. Transthoracic echocardiography if performed meticulously, can depict the defect in aortopulmonary septum. RESULTS:We report a case of large unrepaired aortopulmonary window in a 23 years old patient, diagnosed on transthoracic echocardiography.