抄録
It is difficult for radiologists to identify
the sentinel lymph nodes near the injection site
(shine-through) mapped on lymphoscintigrams.
The purpose of this study was to develop a
computerized scheme for identifying the sentinel
lymph nodes by using a subtraction technique
based on the symmetry of the mapped injection
site. Our database consisted of 78
lymphoscintigrams which were obtained by a
single injection of technetium colloid. The
locations of 99 sentinel lymph nodes on
lymphoscintigrams were determined as "Gold
standard" by the consensus of two experienced
radiologists who referred to the identification
results based on a gamma probe. In our
computerized scheme, the mapped injection site
was first segmented from lymphoscintigram by a
gray-level thresholding technique. The
lymphoscintigram was divided into four regions by
the vertical straight line and the horizontal
straight line through the center of the segmented
injection site. The areas with high pixel values in
the subtraction image between each region and the
similar region were finally detected as sentinel
lymph node. With our computerized scheme, the
detection accuracy of sentinel lymph nodes and the
incorrectly detected spots were 83.8% (83/99) and
1.63 per image.
