Edlinger Christoph, Granitz Marcel, Paar Vera, Jung Christian, Pfeil Alexander, Eder Sarah, Wernly Bernhard, Kammler Jürgen, Hergan Klaus, Hoppe Uta C, Steinwender Clemens, Lichtenauer Michael, Kypta Alexander
Clinic of Internal Medicine II, Department of Cardiology, Paracelsus Medical University of Salzburg, Salzburg, Austria.
Department of Radiology, Paracelsus Medical University Salzburg, Salzburg, Austria.
Wien Klin Wochenschr. 2018 Jul;130(13-14):427-435. doi: 10.1007/s00508-018-1334-z. Epub 2018 May 23.
Leadless pacemaker systems are an important upcoming device in clinical rhythmology. Currently two different products are available with the Micra system (Medtronic) being the most used in the clinical setting to date. The possibility to perform magnetic resonance imaging (MRI) is an important feature of modern pacemaker devices. Even though the Micra system is suitable for MRI, little is yet known about its impact on artifacts within the images.
The aim of our ex vivo study was to perform cardiac MRI to quantify the artifacts and to evaluate if artifacts limit or inhibit the assessment of the surrounding myocardium.
After ex vivo implantation of the leadless pacemaker (LP) in a porcine model, hearts were filled with saline solution and fixed on wooden sticks on a plastic container. The model was examined at 1.5 T and at 3 T using conventional sequences and T2 mapping sequences. In addition, conventional X‑rays and computed tomography (CT) scans were performed.
Correct implantation of the LP could be performed in all hearts. In almost all MRI sequences the right ventricle and the septal region surrounding the (LP) were altered by an artifact and therefore would sustain limited assessment; however, the rest of the myocardium remained free of artifacts and evaluable for common radiologic diagnoses. A characteristic shamrock-shaped artifact was generated which appeared to be even more intense in magnitude and brightness when using 3 T compared to 1.5 T.
The use of the Micra system in cardiac MRI appeared to be feasible. In our opinion, it will still be possible to make important clinical cardiac MRI diagnoses (the detection of major ischemic areas or inflammatory processes) in patients using the Micra system. We suggest the use of 1.5 T as the preferred method in clinical practice.
无导线起搏器系统是临床心律学领域即将出现的一种重要设备。目前有两种不同的产品，其中美敦力公司的Micra系统是迄今为止临床应用中最常用的。具备磁共振成像（MRI）功能是现代起搏器设备的一项重要特性。尽管Micra系统适用于MRI检查，但对于其对图像伪影的影响，目前了解甚少。
我们这项体外研究的目的是进行心脏MRI检查，以量化伪影，并评估伪影是否会限制或妨碍对周围心肌的评估。
在猪模型中进行无导线起搏器（LP）的体外植入后，将心脏充满生理盐水，并固定在塑料容器中的木棍上。使用传统序列和T2映射序列，在1.5T和3T场强下对该模型进行检查。此外，还进行了传统X线和计算机断层扫描（CT）。
所有心脏均能正确植入LP。在几乎所有的MRI序列中，右心室以及围绕（LP）的间隔区域都受到伪影的影响，因此评估会受到限制；然而，其余心肌未出现伪影，可用于常规放射学诊断。产生了一种特征性的三叶草形伪影，与1.5T相比，在3T时其强度和亮度似乎更强。
在心脏MRI中使用Micra系统似乎是可行的。我们认为，对于使用Micra系统的患者，仍有可能做出重要的临床心脏MRI诊断（检测主要缺血区域或炎症过程）。我们建议在临床实践中首选1.5T作为检查方法。
