Image Content Extraction: Application to MR Images of the Brain1
Usha Sinha, PhD,
Anthony Ton, MS,
Amy Yaghmai, MD,
Ricky K. Taira, PhD and
Hooshang Kangarloo, MD
1 From the Department of Radiological Sciences, UCLA School of Medicine, 924 Westwood Blvd, Suite 420, Los Angeles, CA 90024 (U.S., A.Y., R.K.T., H.K.); the School of Medicine, New York University, New York, NY (A.T.); and the Department of Radiological Sciences, Children’s Hospital and Medical Center, Seattle, Wash (R.K.T.). Presented as an infoRAD exhibit at the 1999 RSNA scientific assembly. Received April 6, 2000; revision requested May 31 and received August 16; accepted August 29. Address correspondence to U.S. (e-mail: usinha@itmedicine.net).
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Figure 1. Diagram illustrates the general architecture of the image content extraction module.
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Figure 2. User interface for image registration. Top panel shows the atlas image (left), original patient image (center), and resectioned patient image (right). The original patient image data were reconstructed along atlas views to allow visualization of the results of the registration algorithm. Good alignment of the resectioned patient image with the atlas image is readily seen. The section number in the original image data set matches the anatomy within the atlas. Thus, the atlas and patient images were clearly not aligned prior to registration. The bottom panel displays the free-text report (left) and the list of available atlas structures with defined contours (right). The user can display contour models of the structures on all three image data sets.
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Figure 3. User interface for image registration. Top panel shows the contours of the structures contained in the report as seen on the atlas image (left), the original patient image (center), and the resectioned patient image (right). Below each image is a text field showing the sections in that data set containing the structure of interest. The table (lower left panel) shows the findings and attributes outputted by the NLP and identifies one structure from the free-text report in Figure 2 as "ventricle" modified by "lateral." The synonym dictionary (Term Mapper) helps map this anatomic description to the corresponding term or terms in the atlas. Because the radiology report did not specify any details beyond "lateral ventricle," the Term Mapper found seven structures in the atlas that included this term in the description. The lower right panel displays some (but not all) of the structures identified by the NLP because the atlas presently contains only a limited number of defined structures, resulting in incomplete labeling of the patient images. In contrast, all terms in the atlas that matched the location attribute "lateral ventricles" identified by the NLP are listed.
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Figure 4a. Contours rated as "good" by the radiologist. MR images show the automated contour for the corpus callosum (arrows in a) and cingulate nucleus (arrows in b).
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Figure 4b. Contours rated as "good" by the radiologist. MR images show the automated contour for the corpus callosum (arrows in a) and cingulate nucleus (arrows in b).
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Figure 5a. Contours rated as "moderate" by the radiologist. MR images show the automated contour for the olfactory sulcus (arrows in a) and for part of the lateral ventricles (arrows in b).
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Figure 5b. Contours rated as "moderate" by the radiologist. MR images show the automated contour for the olfactory sulcus (arrows in a) and for part of the lateral ventricles (arrows in b).
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Figure 6a. Contours rated as "poor" by the radiologist. Brain MR images show structures that have been incorrectly identified by the automated algorithm, including the corpus callosum (a) and part of the lateral ventricles (b). Arrow indicates the contours generated by the automated algorithm for these two structures.
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Figure 6b. Contours rated as "poor" by the radiologist. Brain MR images show structures that have been incorrectly identified by the automated algorithm, including the corpus callosum (a) and part of the lateral ventricles (b). Arrow indicates the contours generated by the automated algorithm for these two structures.
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Figure 7a. Structures identified accurately by the automated algorithm. MR images show the atrium and occipital horn of the lateral ventricles (medial surface) (arrow in a), the hippocampal formation (inferior surface) (arrow in b), the olfactory sulcus (arrow in c), and the temporal horn of the lateral ventricles (arrow in d). The smallest structure that was contoured accurately in most patients was the temporal horn of the lateral ventricle (2-3 mm).
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Figure 7b. Structures identified accurately by the automated algorithm. MR images show the atrium and occipital horn of the lateral ventricles (medial surface) (arrow in a), the hippocampal formation (inferior surface) (arrow in b), the olfactory sulcus (arrow in c), and the temporal horn of the lateral ventricles (arrow in d). The smallest structure that was contoured accurately in most patients was the temporal horn of the lateral ventricle (2-3 mm).
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Figure 7c. Structures identified accurately by the automated algorithm. MR images show the atrium and occipital horn of the lateral ventricles (medial surface) (arrow in a), the hippocampal formation (inferior surface) (arrow in b), the olfactory sulcus (arrow in c), and the temporal horn of the lateral ventricles (arrow in d). The smallest structure that was contoured accurately in most patients was the temporal horn of the lateral ventricle (2-3 mm).
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Figure 7d. Structures identified accurately by the automated algorithm. MR images show the atrium and occipital horn of the lateral ventricles (medial surface) (arrow in a), the hippocampal formation (inferior surface) (arrow in b), the olfactory sulcus (arrow in c), and the temporal horn of the lateral ventricles (arrow in d). The smallest structure that was contoured accurately in most patients was the temporal horn of the lateral ventricle (2-3 mm).
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Figure 8a. Effect of a large tumor with edema on structure identification. (a) MR image shows a tumor distorting the normal anatomy and causing incorrect location of the contours of the lateral ventricles (arrow). (b) MR image demonstrates normal findings with accurate identification of structures (arrow).
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Figure 8b. Effect of a large tumor with edema on structure identification. (a) MR image shows a tumor distorting the normal anatomy and causing incorrect location of the contours of the lateral ventricles (arrow). (b) MR image demonstrates normal findings with accurate identification of structures (arrow).
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Copyright © 2001 by the Radiological Society of North America.
