Clinical utility and safety of a protocol for noncardiac and cardiac magnetic resonance imaging of patients with permanent pacemakers and implantable- cardioverter defibrillators at 1.5 tesla
Clinical utility and safety of a protocol for noncardiac and cardiac magnetic resonance imaging of patients with permanent pacemakers and implantable- cardioverter defibrillators at 1.5 tesla
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DOI：
10.1161/circulationaha.105.607655
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发表时间：
2006-09-19
期刊：
影响因子：
37.8
通讯作者：
Halperin, Henry R.
中科院分区：
文献类型：
--
作者：
Nazarian, Saman;Roguin, Ariel;Halperin, Henry R.
背景-由于植入式心脏装置的存在，磁共振成像（MRI）是一种重要的诊断方式，目前数百万患者无法使用。我们试图使用一种协议来评估 1.5T 下非心脏和心脏 MRI 的诊断效用和安全性，该协议结合了设备选择和编程，并限制了 MRI 序列的估计比吸收率。方法和结果 - 没有成像替代方案且使用经体外模型和体内动物测试证明 MRI 安全的设备的患者被纳入。在接受 68 项 MRI 研究的 55 名患者中，31 名患者佩戴了起搏器，24 名患者佩戴了植入式除颤器。对于依赖起搏器的患者，起搏模式改为“异步”，而对于其他患者则改为“需求”。磁体反应和快速心律失常功能被禁用。监测血压、心电图、血氧饱和度和症状。我们努力将系统估计的全身平均比吸收率限制在 2.0 W/kg（在 > 99% 的序列中成功），同时保持 MRI 的诊断能力。没有观察到不适当的起搏抑制或激活事件。基线和即时或长期（MRI 后中位 99 天）感知幅度、导线阻抗或起搏阈值之间没有显着差异。 100% 的非胸部研究和 93% 的胸部研究回答了诊断问题。临床结果包括血管异常的诊断（9 名患者）、恶性肿瘤的诊断或分期（9 名患者）以及心脏活力的评估（13 名患者）。结论 - 如果采取适当的预防措施，非心脏和心脏 MRI 可以在选定的植入式起搏器和除颤器系统的患者中安全地进行。
Background-Magnetic resonance imaging (MRI) is an important diagnostic modality currently unavailable for millions of patients because of the presence of implantable cardiac devices. We sought to evaluate the diagnostic utility and safety of noncardiac and cardiac MRI at 1.5T using a protocol that incorporates device selection and programming and limits the estimated specific absorption rate of MRI sequences.Methods and Results-Patients with no imaging alternative and with devices shown to be MRI safe by in vitro phantom and in vivo animal testing were enrolled. Of 55 patients who underwent 68 MRI studies, 31 had a pacemaker, and 24 had an implantable defibrillator. Pacing mode was changed to "asynchronous" for pacemaker-dependent patients and to "demand" for others. Magnet response and tachyarrhythmia functions were disabled. Blood pressure, ECG, oximetry, and symptoms were monitored. Efforts were made to limit the system-estimated whole-body average specific absorption rate to 2.0 W/ kg (successful in > 99% of sequences) while maintaining the diagnostic capability of MRI. No episodes of inappropriate inhibition or activation of pacing were observed. There were no significant differences between baseline and immediate or long-term (median 99 days after MRI) sensing amplitudes, lead impedances, or pacing thresholds. Diagnostic questions were answered in 100% of nonthoracic and 93% of thoracic studies. Clinical findings included diagnosis of vascular abnormalities (9 patients), diagnosis or staging of malignancy (9 patients), and assessment of cardiac viability (13 patients).Conclusions-Given appropriate precautions, noncardiac and cardiac MRI can potentially be safely performed in patients with selected implantable pacemaker and defibrillator systems.