Ablation zone visualization enhancement by periodic contrast-enhancement computed tomography during microwave ablation.
Ablation zone visualization enhancement by periodic contrast-enhancement computed tomography during microwave ablation.
复制标题
微波消融期间通过定期对比增强计算机断层扫描增强消融区域可视化。
DOI：
10.1002/mp.12266
复制
发表时间：
2017
期刊：
影响因子：
3.8
通讯作者：
Brace,ChristopherL
中科院分区：
文献类型：
--
作者：
Wu,Po-Hung;Borden,Zachary;Brace,ChristopherL
目的术中对比增强计算机断层扫描（CECT）已被提议用于监测热消融的增长。多次CT采集的主要挑战是降低辐射剂量，同时保持足够的图像质量。本研究的目的是评估应用局部高度约束反投影重建（HYPR‐LR）的可行性，定期CECT图像采集与低剂量协议，并确定是否消融可见CT上的大体pathology.MethodsLow ‐dose（），颞CECT体积在微波消融过程中采集正常猪肝。在图像配准后对每个体积进行HYPR处理。采集消融信噪比（SNR）和对比噪声比（CNR），评价图像质量和消融区可视化的增强程度。在HYPR和非HYPR图像上手动分割消融区，并使用Dice系数进行空间比较。消融区的尺寸也进行了比较，大体病理学的相关性和尺寸difference.ResultsSNR和CNR的消融区后HYPR处理增加。手动分割的消融区与大体病理学高度相似，Dice系数为0.81 ± 0.03，而低剂量CECT的Dice系数较小，为0.72 ± 0.05。HYPR和低剂量CECT均与大体病理学具有高度相关性（分别为0.99和0.94），但与未处理图像相比，HYPR处理后的测量值方差较低。HYPR图像的面积、长轴长度和短轴长度的相对差异分别为13.1 ± 5.6%、9.7 ± 4.2%和15.2 ± 2.8%，分别低于低剂量CECT的37.5 ± 6.0%、17.7 ± 2.8%、结论对周期性CECT图像进行HYPR处理，可提高消融区的显示效果。HYPR处理可能会在辐射剂量严格规定的情况下，在真实的消融监测中启用CECT。
PurposeIntra‐procedural contrast‐enhanced computed tomography (CECT) has been proposed to monitor the growth of thermal ablations. The primary challenge with multiple CT acquisitions is reducing radiation dose while maintaining sufficient image quality. The purpose of this study was to evaluate the feasibility of applying local highly constrained backprojection reconstruction (HYPR‐LR) on periodic CECT images acquired with low‐dose protocols, and to determine whether the ablations visible on CT were commensurate to gross pathology.MethodsLow‐dose (), temporal CECT volumes were acquired during microwave ablation on normal porcine liver. HYPR processing was performed on each volume after image registration. Ablation signal‐to‐noise ratio (SNR) and contrast‐to‐noise ratio (CNR) were collected to evaluate the degree of enhancement of image quality and ablation zone visualization. Ablation zones were manually segmented on HYPR and non‐HYPR images and compared spatially using Dice's coefficient. The dimensions of ablation zones were also compared to gross pathology by correlation and dimensional differences.ResultsThe SNR and CNR of ablation zones were increased after HYPR processing. The manually segmented ablation zone was highly similar to gross pathology with a Dice coefficient of 0.81 ± 0.03, while the low‐dose CECT had a smaller Dice coefficient of 0.72 ± 0.05. Both HYPR and low‐dose CECT had high correlation to gross pathology (0.99 and 0.94, respectively), but the variance of measurements were lower after HYPR processing compared to unprocessed images. The relative difference in area, length of long axis, and length of short axis for HYPR image were 13.1 ± 5.6%, 9.7 ± 4.2%, and 15.2 ± 2.8%, which were lower than those for low‐dose CECT at 37.5 ± 6.0%, 17.7 ± 2.8%, and 28.9 ± 5.4%.ConclusionHYPR processing applied to periodic CECT images can enhance ablation zone visualization. HYPR processing may potentially enable CECT in real‐time ablation monitoring under strict regulation of radiation dose.