14 research outputs found
Correction: Reproducibility of Frankfort Horizontal Plane on 3D Multi-Planar Reconstructed MR Images
Reproducibility of Frankfort horizontal plane on 3D multi-planar reconstructed MR images.
OBJECTIVE: The purpose of this study was to determine the accuracy and reliability of Frankfort horizontal plane identification using displays of multi-planar reconstructed MRI images, and propose it as a sufficiently stable and standardized reference plane for craniofacial structures. MATERIALS AND METHODS: MRI images of 43 subjects were obtained from the longitudinal population based cohort study SHIP-2 using a T1-weighted 3D sequence. Five examiners independently identified the three landmarks that form FH plane. Intra-examiner reproducibility and inter-examiner reliability, correlation coefficients (ICC), coefficient of variability and Bland-Altman plots were obtained for all landmarks coordinates to assess reproducibility. Intra-examiner reproducibility and inter-examiner reliability in terms of location and plane angulation were also assessed. RESULTS: Intra- and inter-examiner reliabilities for X, Y and Z coordinates of all three landmarks were excellent with ICC values ranging from 0.914 to 0.998. Differences among examiners were more in X and Z than in Y dimensions. The Bland-Altman analysis demonstrated excellent intra- as well as inter-examiner agreement between examiners in all coordinates for all landmarks. Intra-examiner reproducibility and inter-examiner reliability of the three landmarks in terms of distance showed mean differences between 1.3 to 2.9 mm, Mean differences in plane angulation were between 1.0° to 1.5° among examiners. CONCLUSION: This study revealed excellent intra-examiner reproducibility and inter-examiner reliability of Frankfort Horizontal plane through 3D landmark identification in MRI. Sufficiently stable landmark-based reference plane could be used for different treatments and studies
Correction: Reproducibility of Frankfort Horizontal Plane on 3D Multi-Planar Reconstructed MR Images
Axial head view, A. FH plane estimated prior scan on subjects head B. FH plane identified by landmarks on Images.
<p>(Note the differences in the muscles cross sectional area between both views).</p
Bland-Altman Plot for Examiner 1 vs. Examiner 5.
<p>a) in x coordinate of left Orbitale (the shown digit preference reflects the slice thickness of 1 mm) b) In y coordinate of left Orbitale.</p
Inter-Examiner Reliability – Mean differences, Coefficients of Variability (CV) and Intra-class Correlation statistics.
<p>Inter-Examiner Reliability – Mean differences, Coefficients of Variability (CV) and Intra-class Correlation statistics.</p
Images were viewed using multi planar reconstruction (MPR) with coronal view as the center of orientation.
<p>a) Horizontal and vertical lines were adjusted until the standard trans-porionic axis was observed. b) Balance between axial, coronal and sagittal axis adjusted to connect trans-porionic axis (purple) with Orbitale through a coronal axis (blue). c) Axial view through FH after connecting the 3 axes.</p
Intra- Examiner Reproducibility and Inter-Examiner Reliability – Reader Differences in Dihedral Angle of FH Plane.
<p>Intra- Examiner Reproducibility and Inter-Examiner Reliability – Reader Differences in Dihedral Angle of FH Plane.</p
Plotted landmarks on 3D rendered images with MPR view.
<p>Plotted landmarks on 3D rendered images with MPR view.</p