Biomechanics and Spine Research Group, Queensland University of Technology, Brisbane, Queensland, Australia.
Mater Medical Imaging, Mater Misericordiae Brisbane Ltd, South Brisbane, Queensland, Australia.
BMJ Open. 2019 Aug 1;9(8):e027020. doi: 10.1136/bmjopen-2018-027020.
Single-use commercial surface fiducial markers are used in clinical imaging for a variety of applications. The current study sought to find a new, reliably visible, easily sourced and inexpensive fiducial marker alternative for use with MRI.
Five commonly requested MRI sequences were determined (three-dimensional (3D) T1-weighted, T1 coronal, 3D T2-weighted, T2 fat suppressed, proton density), to examine the visibility of 18 items (including a commercial fiducial marker).
Clinical 3T MRI scanner in an Australian Tertiary Hospital and an Australian University Biomedical Engineering research group.
18 marker alternatives were scanned using five common MRI sequences. Images were reformatted to obtain both an image through the mid-height of each marker and a maximum intensity z-projection image over the volume of the marker. Variations in marker intensity were profiled across each visible marker and a visibility rating defined.
Outcome measures were based on quantitative assessment of a clear intensity contrast ratio between the marker and the adjacent tissue and a qualitative assessment of visibility via a 3-point scale.
The fish oil capsule, vitamin D capsule, paint ball pellet, soy sauce sushi tube and commercial markers were typically visible to a high quality on all the imaging sequences and demonstrated a clear differential in intensity contrast against the adjacent tissue. Other common items, such as plasticine 'play doh' and a soft 'Jelly baby' sweet, were surprise candidates, demonstrating high-quality visibility and intensity contrast for the 3D T1-weighted sequence.
Depending on the basis for referral and MRI sequence chosen, four alternative fiducial markers were determined to be inexpensive, easily sourced and consistently visible. Of these, the vitamin D capsule provided an excellent balance between availability, size, cost, usability and quality of the visualised marker for all the commonly used MRI sequences analysed.
一次性商用表面基准标记物在各种临床成像应用中被广泛使用。本研究旨在寻找一种新的、可靠可见、易于获取且经济实惠的基准标记物替代物，用于 MRI。
确定了五种常用的 MRI 序列（三维 T1 加权、T1 冠状位、三维 T2 加权、T2 脂肪抑制、质子密度），以检查 18 个项目（包括商业基准标记物）的可见性。
澳大利亚三级医院的临床 3T MRI 扫描仪和澳大利亚大学生物医学工程研究组。
使用五种常见的 MRI 序列对 18 种标记替代物进行扫描。对图像进行重新格式化，以获得每个标记物的中间高度的图像和标记物体积的最大强度 z 投影图像。对每个可见标记物的标记强度变化进行分析，并定义可见性评分。
观察指标基于标记物与相邻组织之间的清晰强度对比度的定量评估，以及通过 3 分制的定性评估。
鱼油胶囊、维生素 D 胶囊、彩弹丸、酱油寿司管和商业标记物在所有成像序列上通常都具有高质量的可见性，并显示出与相邻组织之间明显的强度对比度差异。其他常见物品，如塑料泥“Play Doh”和软“Jelly baby”糖，出人意料地成为了候选物，在三维 T1 加权序列中显示出高质量的可见性和强度对比度。
根据转诊的依据和选择的 MRI 序列，确定了四种替代基准标记物，它们价格低廉、易于获取且具有一致性的可见性。在分析的所有常用 MRI 序列中，维生素 D 胶囊在可用性、尺寸、成本、易用性和可视化标记物的质量之间提供了极好的平衡。
