Department of Diagnostic and Interventional Radiology, University Hospital Cologne, Cologne, Germany.
Institute of Diagnostic and Interventional Radiology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany; Department of Cardiology and Pneumology, University Medical Center Göttingen, Göttingen, Germany.
Acad Radiol. 2021 Jan;28(1):77-84. doi: 10.1016/j.acra.2019.12.006. Epub 2020 Jan 31.
The purpose of our study was to evaluate magnetic resonance (MR) artifacts related to breast tissue markers in breast imaging procedures.
In this bicentric prospective ex vivo study 10 different commercially available markers were measured in self-made breast phantoms. Breast tissue markers varying in marker size, composition, and shape were evaluated. MR imaging (MRI) scans were performed on 1.5 Tesla (T) and 3 T scanners from 2 different vendors, using dedicated breast coils. Three different sequences (T1-weighted images with and without fat saturation, T2-weighted images) were acquired in axial and coronal view. Three blinded readers electronically measured the artifact length.
All markers caused artifacts in MRI. The largest median artifact length was 10.4 mm, interquartile range (IQR 9.4-11.0 mm), the smallest 4.8 mm (IQR 4.5-5.2 mm). Relative artifact length (quotient artifact length in mm/real physical length of the marker) ranged between 0.9 (IQR 0.9-1.2) and 3.0 (IQR 2.8-3.4). Mean artifact length was higher for metallic markers (10.2 mm; IQR 8.7-11.5 mm) compared to metallic markers with nonmetallic coating (7.7 mm; IQR 6.3-10.2 mm) and nonmetallic marker (7.6 mm; IQR 5.9-10.0 mm); all p < 0.0001. Artifact size was higher in coronal in comparison to axial view; p < 0.05. The results were comparable between the different field strengths, the sites and sequences; p > 0.05. Interobserver agreement was excellent (ntraclass correlation coefficient = 0.83).
Artifacts are necessary in the detection and localization of breast tissue markers, but could also limit the interpretation of MRI due to the possibility of masking the residual tumor after biopsy. This artifact size varies among the different clips evaluated. It depends on marker composition and scan direction but is not influenced by image sequence, field strength or scanner type.
本研究旨在评估乳腺成像过程中与乳腺组织标志物相关的磁共振（MR）伪影。
在这项双中心前瞻性离体研究中，我们在自制的乳腺体模中测量了 10 种不同的市售标志物。评估了不同的标志物尺寸、组成和形状。在来自 2 个不同供应商的 1.5T（T）和 3T 扫描仪上进行磁共振成像（MRI）扫描，使用专用乳腺线圈。在轴位和冠状位采集 3 种不同序列（带和不带脂肪饱和的 T1 加权图像、T2 加权图像）。3 位盲法读者电子测量伪影长度。
所有标志物在 MRI 中均产生伪影。最大的中位数伪影长度为 10.4mm（IQR 9.4-11.0mm），最小的为 4.8mm（IQR 4.5-5.2mm）。相对伪影长度（以毫米表示的伪影长度与标志物的实际物理长度之比）范围在 0.9（IQR 0.9-1.2）至 3.0（IQR 2.8-3.4）之间。与具有非金属涂层的金属标志物（7.7mm；IQR 6.3-10.2mm）和非金属标志物（7.6mm；IQR 5.9-10.0mm）相比，金属标志物的平均伪影长度（10.2mm；IQR 8.7-11.5mm）更高；所有 p<0.0001。冠状位的伪影尺寸大于轴位；p<0.05。不同场强、部位和序列之间的结果相当；p>0.05。观察者间一致性极好（ntraclass 相关系数=0.83）。
乳腺组织标志物的检测和定位需要伪影，但由于活检后残留肿瘤的可能性被掩盖，也可能会限制 MRI 的解读。不同夹片中的这种伪影大小不同。它取决于标志物的组成和扫描方向，但不受图像序列、场强或扫描仪类型的影响。
