IEEE Trans Biomed Eng. 2019 Jan;66(1):14-22. doi: 10.1109/TBME.2018.2828304. Epub 2018 Apr 19.
This investigation was performed to evaluate the registration accuracy between magnetic resonance imaging (MRI) and pathology using three-dimensional (3-D) printed molds.
Tissue-mimicking prostate phantoms were manufactured with embedded fiducials. The fiducials were used to measure and compare target registration error (TRE) between phantoms that were sliced by hand versus phantoms that were sliced within 3-D-printed molds. Subsequently, ten radical prostatectomy specimens were placed inside molds, scanned with MRI, and then sliced. The ex vivo scan was used to assess the true location of whole mount (WM) slides relative to in vivo MRI. The TRE between WM and in vivo MRI was measured using anatomic landmarks.
Manually sliced phantoms had a 4.1-mm mean TRE, whereas mold-sliced phantoms had a 1.9-mm mean TRE. Similarly, mold-assisted slicing reduced mean angular misalignment around the left-right (LR) anatomic axis from 10.7° to 4.5°. However, ex vivo MRI revealed that excised prostates were misaligned within molds, including a mean 14° rotation about the LR axis. The mean in-plane TRE was 3.3 mm using molds alone and 2.2 mm after registration was corrected with ex vivo MRI.
Patient-specific molds improved accuracy relative to manual slicing techniques in a phantom model. However, the registration accuracy of surgically resected specimens was limited by their imperfect fit within molds. This limitation can be overcome with the addition of ex vivo imaging.
The accuracy of 3-D-printed molds was characterized, quantifying their utility for facilitating MRI-pathology registration.
本研究旨在评估使用三维（3-D）打印模具进行磁共振成像（MRI）和病理学配准的准确性。
制造了带有嵌入式基准标记的组织模拟前列腺模型。使用这些基准标记来测量和比较手动切片的模型与在 3-D 打印模具内切片的模型之间的靶区配准误差（TRE）。随后，将十个根治性前列腺切除术标本置于模具内，用 MRI 扫描，然后切片。离体扫描用于评估全载玻片（WM）相对于体内 MRI 的真实位置。使用解剖学标志测量 WM 与体内 MRI 之间的 TRE。
手动切片的模型平均 TRE 为 4.1mm，而模具切片的模型平均 TRE 为 1.9mm。同样，模具辅助切片使左右（LR）解剖轴周围的平均角度偏差从 10.7°减小到 4.5°。然而，离体 MRI 显示，切除的前列腺在模具内存在错位，包括 LR 轴平均 14°的旋转。单独使用模具的平均平面 TRE 为 3.3mm，经离体 MRI 校正后注册的平均 TRE 为 2.2mm。
在体模模型中，与手动切片技术相比，患者特异性模具提高了准确性。然而，手术切除标本的配准准确性受到其在模具内不完美贴合的限制。可以通过添加离体成像来克服这种限制。
对 3-D 打印模具的准确性进行了描述，定量评估了其在促进 MRI-病理学配准中的效用。
