Lee Hyunna, Lee Jeongjin, Kim Bohyoung, Kim Se Hyung, Shin Yeong-Gil
IEEE Trans Biomed Eng. 2014 Jul;61(7):2102-11. doi: 10.1109/TBME.2014.2313888. Epub 2014 Mar 26.
In this paper, we propose a fast three-material modeling for electronic cleansing (EC) in computed tomographic colonography. Using a triple arch projection, our three-material modeling provides a very quick estimate of the three-material fractions to remove ridge-shaped artifacts at the T-junctions where air, soft-tissue (ST), and tagged residues (TRs) meet simultaneously. In our approach, colonic components including air, TR, the layer between air and TR, the layer between ST and TR (L(ST/TR)), and the T-junction are first segmented. Subsequently, the material fraction of ST for each voxel in L(ST/TR) and the T-junction is determined. Two-material fractions of the voxels in L(ST/TR) are derived based on a two-material transition model. On the other hand, three-material fractions of the voxels in the T-junction are estimated based on our fast three-material modeling with triple arch projection. Finally, the CT density value of each voxel is updated based on our fold-preserving reconstruction model. Experimental results using ten clinical datasets demonstrate that the proposed three-material modeling successfully removed the T-junction artifacts and clearly reconstructed the whole colon surface while preserving the submerged folds well. Furthermore, compared with the previous three-material transition model, the proposed three-material modeling resulted in about a five-fold increase in speed with the better preservation of submerged folds and the similar level of cleansing quality in T-junction regions.
在本文中，我们提出了一种用于计算机断层结肠成像中电子清洗（EC）的快速三材料建模方法。通过三重弓投影，我们的三材料建模能够非常快速地估计三材料分数，以去除空气、软组织（ST）和标记残留物（TRs）同时相遇的T形交界处的脊状伪影。在我们的方法中，首先对包括空气、TR、空气与TR之间的层、ST与TR之间的层（L(ST/TR)）以及T形交界处在内的结肠成分进行分割。随后，确定L(ST/TR)和T形交界处中每个体素的ST材料分数。基于双材料过渡模型推导L(ST/TR)中体素的双材料分数。另一方面，基于我们带有三重弓投影的快速三材料建模来估计T形交界处中体素的三材料分数。最后，基于我们的保褶重建模型更新每个体素的CT密度值。使用十个临床数据集的实验结果表明，所提出的三材料建模成功地去除了T形交界处的伪影，并清晰地重建了整个结肠表面，同时很好地保留了凹陷的褶皱。此外，与先前的三材料过渡模型相比，所提出的三材料建模在速度上提高了约五倍，同时更好地保留了凹陷的褶皱，并且在T形交界处区域的清洗质量水平相似。
