Heart Rate-Independent 3D Myocardial Blood Oxygen Level-Dependent MRI at 3.0 T with Simultaneous 13N-Ammonia PET Validation.
- 作者列表："Yang HJ","Dey D","Sykes J","Butler J","Biernaski H","Kovacs M","Bi X","Sharif B","Cokic I","Tang R","Slomka P","Prato FS","Dharmakumar R
:Background Despite advances, blood oxygen level-dependent (BOLD) cardiac MRI for myocardial perfusion is limited by inadequate spatial coverage, imaging speed, multiple breath holds, and imaging artifacts, particularly at 3.0 T. Purpose To develop and validate a robust, contrast agent-unenhanced, free-breathing three-dimensional (3D) cardiac MRI approach for reliably examining changes in myocardial perfusion between rest and adenosine stress. Materials and Methods A heart rate-independent, free-breathing 3D T2 mapping technique at 3.0 T that can be completed within the period of adenosine stress (≤4 minutes) was developed by using computer simulations, ex vivo heart preparations, and dogs. Studies in dogs were performed with and without coronary stenosis and validated with simultaneously acquired nitrogen 13 (13N) ammonia PET perfusion in a clinical PET/MRI system. The MRI approach was also prospectively evaluated in healthy human volunteers (from January 2017 to September 2017). Myocardial BOLD responses (MBRs) between normal and ischemic myocardium were compared with mixed model analysis. Results Dogs (n = 10; weight range, 20-25 kg; mongrel dogs) and healthy human volunteers (n = 10; age range, 22-53 years; seven men) were evaluated. In healthy dogs, T2 MRI at adenosine stress was greater than at rest (mean rest vs stress, 38.7 msec ± 2.5 [standard deviation] vs 45.4 msec ± 3.3, respectively; MBR, 1.19 ± 0.08; both, P < .001). At the same conditions, mean rest versus stress PET perfusion was 1.1 mL/mg/min ± 0.11 versus 2.3 mL/mg/min ± 0.82, respectively (P < .001); myocardial perfusion reserve (MPR) was 2.4 ± 0.82 (P < .001). The BOLD response and PET MPR were positively correlated (R = 0.67; P < .001). In dogs with coronary stenosis, perfusion anomalies were detected on the basis of MBR (normal vs ischemic, 1.09 ± 0.05 vs 1.00 ± 0.04, respectively; P < .001) and MPR (normal vs ischemic, 2.7 ± 0.08 vs 1.7 ± 1.1, respectively; P < .001). Human volunteers showed increased myocardial T2 at stress (rest vs stress, 44.5 msec ± 2.6 vs 49.0 msec ± 5.5, respectively; P = .004; MBR, 1.1 msec ± 8.08). Conclusion This three-dimensional cardiac blood oxygen level-dependent (BOLD) MRI approach overcame key limitations associated with conventional cardiac BOLD MRI by enabling whole-heart coverage within the standard duration of adenosine infusion, and increased the magnitude and reliability of BOLD contrast, which may be performed without requiring breath holds. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Almeida in this issue.
尽管取得了进展，但用于心肌灌注的血氧水平依赖性 (BOLD) 心脏MRI受到空间覆盖不足、成像速度、多次屏气和成像伪影的限制，特别是在3.0 T。目的开发和验证一种可靠的、造影剂未增强的、自由呼吸的三维 (3D) 心脏MRI方法，用于可靠地检查静息和腺苷应激之间心肌灌注的变化。材料和方法通过使用计算机模拟、离体心脏准备和狗开发了可在腺苷应激期间 (≤ 4分钟) 完成的3.0 T下的心率非依赖性、自由呼吸3D T2映射技术。在具有和不具有冠状动脉狭窄的情况下对狗进行研究，并在临床PET/MRI系统中用同时获得的氮13 (13N) 氨PET灌注进行验证。MRI方法也在健康志愿者中进行了前瞻性评估 (从2017年1月至2017年9月)。采用混合模型分析比较正常心肌和缺血心肌的BOLD反应 (MBRs)。结果评估了狗 (n = 10; 体重范围，20-25千克kg; 杂种犬) 和健康人志愿者 (n = 10; 年龄范围，22-53岁; 7名男性)。在健康狗中，腺苷应激时的T2 MRI大于静息时 (平均静息vs应激，分别为38.7 msec ± 2.5 [标准差] vs 45.4 msec ± 3.3; MBR，1.19 ± 0.08; 两者，P <.001)。在相同条件下，平均静息与应激PET灌注分别为1.1 ml/min ± 0.11和2.3 ml/min ± 0.82 (P < .001); 心肌灌注储备 (MPR) 为2.4 ± 0.82 (P <.001)。BOLD反应与PET MPR呈正相关 (R = 0.67; P <.001)。在冠状动脉狭窄的狗中，在MBR (正常vs缺血，分别为1.09 ± 0.05 vs 1.00 ± 0.04; P < .001) 和MPR (正常vs缺血，分别为2.7 ± 0.08 vs 1.7 ± 1.1; P < .001) 的基础上检测到灌注异常。人类志愿者在应激时表现出增加的心肌T2 (静息vs应激，分别为44.5 msec ± 2.6 vs 49.0 msec ± 5.5; P = .004; MBR，1.1 msec ± 8.08)。结论: 这种三维心脏血氧水平依赖性 (BOLD) MRI方法克服了与传统心脏BOLD MRI相关的关键局限性，通过使全心脏覆盖在腺苷输注的标准持续时间内，并增加BOLD对比的幅度和可靠性，可以在不需要屏气的情况下进行。©RSNA，2020在线补充材料可用于本文。另见本期阿尔梅达的社论。
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.