本研究旨在调查植入型心律监测器 (ILR) 患者进行乳腺 MRI 检查和引导活检的可行性，以及 ILR 对图像解读的影响。该回顾性研究检查了 2008 年 4 月至 2022 年 9 月期间带有 ILR 的乳腺 MRI。对人口特征、安全问题和影像结果进行了放射学报告和电子病历的回顾。通过对 MR 图像进行统计分析，比较了不同脉冲序列的伪影定量。整个研究期间共有 40/82,778 (0.049%) 例乳腺 MRI 包括 ILR。所有 MRI 检查均完成，无早期终止。未发生与患者或设备相关的不良事件。ILR 最常位于左下内侧象限 (64.6%)。主要伪影是位于 ILR 区域的双极形成的信号强度 (SI) 缺失，有或无外围高 SI 区域。伪影在矢状轴上最为显著 (p < 0.001)，其次是前后轴 (p < 0.001)，然后是左右轴。伪增强样伪影在后对比增强和减法 T1 加权图像上最为明显，类似于可疑强化。伪影在扩散加权图像上最为突出 (p < 0.001)，其次是 T2 加权和 T1 加权图像。在八名患者中，MRI 检查发现了可疑的异常结果，导致额外发现四个恶性病灶。在六名左侧乳腺癌患者中，肿瘤在五例中完全可见，在一例中部分遮挡。乳腺 MRI 在 ILR 患者中是可行且安全的，可能提供重要的诊断价值，尽管存在局部特征性伪影。在 ILR 患者中，指征的乳腺 MRI 检查和引导活检可以安全进行。然而，放射科医师应该注意相关限制，包括对左侧乳房内部的有限评估和伪增强伪影。• 在植入型心律监测器患者中进行乳腺 MRI 是一种不常见、可行且安全的程序。• 尽管乳房可视化受限于植入型心律监测器区域和特征性伪影，MRI 在 40 例中显示出额外病变的情况为 8 例 (20%)，其中一半为恶性病变。• 在植入型心律监测器患者中进行乳腺 MRI 应在适应症情况下进行，同时考虑典型的相关伪影。© 2023. 作者，独家授权给欧洲放射学会。

To investigate the feasibility of breast MRI exams and guided biopsies in patients with an implantable loop recorder (ILR) as well as the impact ILRs may have on image interpretation.This retrospective study examined breast MRIs of patients with ILR, from April 2008 to September 2022. Radiological reports and electronic medical records were reviewed for demographic characteristics, safety concerns, and imaging findings. MR images were analyzed and compared statistically for artifact quantification on the various pulse sequences.Overall, 40/82,778 (0.049%) MRIs during the study period included ILR. All MRIs were completed without early termination. No patient-related or device-related adverse events occurred. ILRs were most commonly located in the left lower-inner quadrant (64.6%). The main artifact was a signal intensity (SI) void in a dipole formation in the ILR bed with or without areas of peripheral high SI. Artifacts appeared greatest in the cranio-caudal axis (p < 0.001), followed by the anterior-posterior axis (p < 0.001), and then the right-left axis. High peripheral rim-like SI artifacts appeared on the post-contrast and subtracted T1-weighted images, mimicking suspicious enhancement. Artifacts were most prominent on diffusion-weighted (p < 0.001), followed by T2-weighted and T1-weighted images. In eight patients, suspicious findings were found on MRI, resulting in four additional malignant lesions. Of six patients with left breast cancer, the tumor was completely visible in five cases and partially obscured in one.Breast MRI is feasible and safe among patients with ILR and may provide a significant diagnostic value, albeit with localized, characteristic artifacts.Indicated breast MRI exams and guided biopsies can be safely performed in patients with implantable loop recorder. Nevertheless, radiologists should be aware of associated limitations including limited assessment of the inner left breast and pseudo-enhancement artifacts.• Breast MRI in patients with an implantable loop recorder is an infrequent, feasible, and safe procedure. • Despite limited breast visualization of the implantable loop recorder bed and characteristic artifacts, MRI depicted additional lesions in 8/40 (20%) of cases, half of which were malignant. • Breast MRI in patients with an implantable loop recorder should be performed when indicated, taking into consideration typical associated artifacts.© 2023. The Author(s), under exclusive licence to European Society of Radiology.