Brain Tumor Volume Measurement: Comparison of Manual and Semiautomated Methods1
Bonnie N. Joe, MD, PhD,
Melanie B. Fukui, MD,
Carolyn Cidis Meltzer, MD,
Qing-shou Huang, MS,
Roger S. Day, ScD,
Phil J. Greer, BS and
Michael E. Bozik, MD
1 From the Departments of Radiology, Division of Neuroradiology (B.N.J., M.B.F., C.C.M., P.J.G.), Psychiatry (C.C.M.), Neurosurgery (M.E.B.), Neurology (M.E.B.), and Medicine (M.E.B.), and the Pittsburgh Cancer Institute (Q.H., R.S.D.), University of Pittsburgh Medical Center, Pittsburgh, Pa. Received May 29, 1998; revision requested July 22; revision received November 11; accepted March 29, 1999. Address reprint requests to M.B.F., Department of Radiology, Presbyterian University Hospital, Rm D-132, 200 Lothrop St, Pittsburgh, PA 15213-2582 (e-mail: fukuimb@radserv.arad.upmc.edu).
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Figure 1a. (a, b) Axial T1-weighted MR images (repetition time msec/echo time msec, 466/11) demonstrate the manual trace method in two areas of tumor enhancement (arrows in a) in the left temporal lobe of a patient with glioblastoma multiforme. In b, the contours generated by manually tracing the enhancing portions of the tumor are shown.
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Figure 1b. (a, b) Axial T1-weighted MR images (repetition time msec/echo time msec, 466/11) demonstrate the manual trace method in two areas of tumor enhancement (arrows in a) in the left temporal lobe of a patient with glioblastoma multiforme. In b, the contours generated by manually tracing the enhancing portions of the tumor are shown.
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Figure 2a. (a-d) Axial T1-weighted MR images (466/11) obtained in the same patient and same image section as those in Figure 1 illustrate the semiautomated computer tracing method. (a-c) First, a point just inside the enhancing border (blue dot at tip of arrow in a) is selected. (b, c) Next, a point just outside the enhancing border (yellow dot at tip of arrow in b) is selected. In c, the enhancing area is automatically outlined (shown in red). (d, e) By selecting a point inside the nonenhancing (necrotic) region (blue dot at tip of arrow in d) and a point outside the nonenhancing region (yellow dot at tip of arrow in e), the contour surrounding the nonenhancing area (outlined in red in e) is generated and excluded from the final tumor volume measurement. (In a-e, all dots have been increased from 1 pixel to 4 pixels in width for clarity of reproduction.) (f) The final result after all enhancing areas have been segmented is shown.
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Figure 2b. (a-d) Axial T1-weighted MR images (466/11) obtained in the same patient and same image section as those in Figure 1 illustrate the semiautomated computer tracing method. (a-c) First, a point just inside the enhancing border (blue dot at tip of arrow in a) is selected. (b, c) Next, a point just outside the enhancing border (yellow dot at tip of arrow in b) is selected. In c, the enhancing area is automatically outlined (shown in red). (d, e) By selecting a point inside the nonenhancing (necrotic) region (blue dot at tip of arrow in d) and a point outside the nonenhancing region (yellow dot at tip of arrow in e), the contour surrounding the nonenhancing area (outlined in red in e) is generated and excluded from the final tumor volume measurement. (In a-e, all dots have been increased from 1 pixel to 4 pixels in width for clarity of reproduction.) (f) The final result after all enhancing areas have been segmented is shown.
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Figure 2c. (a-d) Axial T1-weighted MR images (466/11) obtained in the same patient and same image section as those in Figure 1 illustrate the semiautomated computer tracing method. (a-c) First, a point just inside the enhancing border (blue dot at tip of arrow in a) is selected. (b, c) Next, a point just outside the enhancing border (yellow dot at tip of arrow in b) is selected. In c, the enhancing area is automatically outlined (shown in red). (d, e) By selecting a point inside the nonenhancing (necrotic) region (blue dot at tip of arrow in d) and a point outside the nonenhancing region (yellow dot at tip of arrow in e), the contour surrounding the nonenhancing area (outlined in red in e) is generated and excluded from the final tumor volume measurement. (In a-e, all dots have been increased from 1 pixel to 4 pixels in width for clarity of reproduction.) (f) The final result after all enhancing areas have been segmented is shown.
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Figure 2d. (a-d) Axial T1-weighted MR images (466/11) obtained in the same patient and same image section as those in Figure 1 illustrate the semiautomated computer tracing method. (a-c) First, a point just inside the enhancing border (blue dot at tip of arrow in a) is selected. (b, c) Next, a point just outside the enhancing border (yellow dot at tip of arrow in b) is selected. In c, the enhancing area is automatically outlined (shown in red). (d, e) By selecting a point inside the nonenhancing (necrotic) region (blue dot at tip of arrow in d) and a point outside the nonenhancing region (yellow dot at tip of arrow in e), the contour surrounding the nonenhancing area (outlined in red in e) is generated and excluded from the final tumor volume measurement. (In a-e, all dots have been increased from 1 pixel to 4 pixels in width for clarity of reproduction.) (f) The final result after all enhancing areas have been segmented is shown.
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Figure 2e. (a-d) Axial T1-weighted MR images (466/11) obtained in the same patient and same image section as those in Figure 1 illustrate the semiautomated computer tracing method. (a-c) First, a point just inside the enhancing border (blue dot at tip of arrow in a) is selected. (b, c) Next, a point just outside the enhancing border (yellow dot at tip of arrow in b) is selected. In c, the enhancing area is automatically outlined (shown in red). (d, e) By selecting a point inside the nonenhancing (necrotic) region (blue dot at tip of arrow in d) and a point outside the nonenhancing region (yellow dot at tip of arrow in e), the contour surrounding the nonenhancing area (outlined in red in e) is generated and excluded from the final tumor volume measurement. (In a-e, all dots have been increased from 1 pixel to 4 pixels in width for clarity of reproduction.) (f) The final result after all enhancing areas have been segmented is shown.
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Figure 2f. (a-d) Axial T1-weighted MR images (466/11) obtained in the same patient and same image section as those in Figure 1 illustrate the semiautomated computer tracing method. (a-c) First, a point just inside the enhancing border (blue dot at tip of arrow in a) is selected. (b, c) Next, a point just outside the enhancing border (yellow dot at tip of arrow in b) is selected. In c, the enhancing area is automatically outlined (shown in red). (d, e) By selecting a point inside the nonenhancing (necrotic) region (blue dot at tip of arrow in d) and a point outside the nonenhancing region (yellow dot at tip of arrow in e), the contour surrounding the nonenhancing area (outlined in red in e) is generated and excluded from the final tumor volume measurement. (In a-e, all dots have been increased from 1 pixel to 4 pixels in width for clarity of reproduction.) (f) The final result after all enhancing areas have been segmented is shown.
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Figure 3a. Scatterplots of intraoperator agreement indexes for the manual versus semiautomated segmentation method. The dotted line is the line of equality, along which the agreement indexes for the manual and semiautomated methods are equal. Each data point represents one image. (a) Agreement indexes for operator 1. Note that there are more points clustered toward the manual axis; this indicates that operator 1 had better reliability with the manual trace method. (b) Agreement indexes for operator 2. In this case, the points are evenly distributed on both sides of the equality line; this indicates that operator 2 had comparable reliability with the two measurement methods.
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Figure 3b. Scatterplots of intraoperator agreement indexes for the manual versus semiautomated segmentation method. The dotted line is the line of equality, along which the agreement indexes for the manual and semiautomated methods are equal. Each data point represents one image. (a) Agreement indexes for operator 1. Note that there are more points clustered toward the manual axis; this indicates that operator 1 had better reliability with the manual trace method. (b) Agreement indexes for operator 2. In this case, the points are evenly distributed on both sides of the equality line; this indicates that operator 2 had comparable reliability with the two measurement methods.
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Figure 4. Scatterplot of interoperator agreement indexes for the manual versus semiautomated segmentation method. The agreement indexes for the manual and semiautomated methods are equal along the dotted line. The points are evenly distributed on both sides of the equality line; this indicates similar interoperator reliability between the two measurement methods.
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Copyright © 1999 by the Radiological Society of North America.
