Voxel-based Three-dimensional Segmentation of the Capsulo-synovium from Contrast-enhanced MRI Can Represent Clinical Impairments in Adhesive Capsulitis

Figures

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  Figure 1. Anatomical structures that pathologic changes can involve with varying degree of severity according to the disease stage in adhesive capsulitis. CHL = coracohumeral ligament; GHL = glenohumeral ligament.

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  Figure 2. Flow chart for selection of the eligible study subjects. ROM = range of motion; FE = forward elevation; ER = external rotation.

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  Figure 3. Semiautomatic segmentation of the regions of interests (ROIs) using the Fast Marching method of Level Set plugin (https://imagej.net/Level_Sets) in Fiji, an open-source image processing package based on Image J. (A) Before image segmentation, all oblique coronal fat-suppressed enhanced T1-weighted images were imported to the Fiji software and the image dynamic was reduced from 16-bit to an 8-bit type to match the requirements of the used software. In the Fiji environment, the operator manually selected several seed points on the capsulo-synovial enhanced portion in the serial MR image stack. Capsulo-synovial enhanced portion was defined as the area where signal intensity was enhanced and regarded as pathologic condition. (B) Then, we went to the Level Sets plugin dialog and selected the Fast Marching option. Clinking on OK button, Fiji automatically updated progress window (the first, second and third figures) and, after completion, showed a result window (the fourth figure). The segmented area was shown in green in the progress window and black in the result window. To detect segmentation boundaries, the Fast Marching method algorithm expands from a seed point to the…

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  Figure 4. Calculation of total voxel volume and 3D reconstruction of the entire capsulo-synovial enhanced portion on CE-MRI. (A) Regions of interests (ROIs) are automatically created on the capsulo-synovial enhanced portion in all consecutive MR images in the progress windows by the Fast Marching method of Level Set plugin. (B) Segmented area of capsulo-synovial enhanced portion in all consecutive MR images are shown in the result windows by the Fast Marching method of Level Set plugin. (C) Subsequently, using the Voxel Counter plugin, total voxel volume of segmented area of entire capsulo-synovial enhanced portion was automatically calculated in mm3. (D) Finally, 3D shape of the segmentation of entire capsulo-synovial enhanced portion was reconstructed and illustrated by the Volume Viewer plugin.

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  Figure 5. The segmentation of the entire capsulo-synovial enhanced portion of the shoulder joint in adhesive capsulitis was 3-dimensionally reconstructed and illustrated using the 3D Project function in Fiji (supplement material Video 1).

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  Figure 6. The mean total voxel volume of the entire capsulo-synovial enhanced portion showed a significant inverse correlation with the glenohumeral joint volume of shoulder by Pearson’s correlation coefficient (r = −0.528, P < 0.001).