It is known that the spleen accompanied by liver cirrhosis is hypertrophied or enlarged. We have examined a wave pattern at the left boundary of spleen on the abdominal CT images having liver cirrhosis, and found that they are different from those on the images having a normal liver. It is noticed that the abdominal CT images of patient with liver cirrhosis shows strong bending in the wave pattern. In the case of normal liver, the images may also have a wave pattern, but its bends are not strong. Therefore, the total waving area of the spleen with liver cirrhosis is found to be greater than that of the spleen with a normal liver. Moreover, we found that the waves of the spleen from the image with liver cirrhosis have the higher degree of circularity compared to the normal liver case. Based on the two observations above, we propose an automatic method to diagnose splenic enlargement by using the wave pattern of the spleen in abdominal CT images. The proposed automatic method improves the diagnostic performance compared with the conventional process based on the size of spleen.
Diameters (or areas) of vessel cross-sections provide useful information for diagnosis and surgery planning. However, the ordinary centerline-perpendicular cross-sections are often inappropriate to use because the centerline may include unwanted local curvatures in irregular or asymmetric regions and high curvatures in sharply bended regions. In this paper, we try to improve the accuracy of vessel cross-section measurement by properly adjusting the centerline. To alleviate local curvatures in the centerline while preserving the global shape faithfully, we register a deformable cylindrical model onto the vessel lumen, and subsequently adopt the axis of the registered model as the adjusted centerline for determining cross-sections. In addition, by introducing the electric field model, we prevent undesirable intersection of cross-sections that is often found in sharply bended regions. Experiments are performed using various synthesized images that simulate abnormal vessels with stenoses or aneurysms. The results show that the registration process successfully eliminates unwanted local curvatures while preserving the global shape of the vessel, and obtained cross-sections do not intersect each other even in the region of high curvature.