Name: Video: Bone Mask Generation from 3D Slicer Generated File and Statistical Analysis of Identified Bone Erosion in Rheumatoid Arthritis Patients
Uploaded: 2023-10-06T14:05:00
Duration: 2 min 59 s
Description: 214 Views. Bone Mask Generation from 3D Slicer Generated File and Statistical Analysis of Identified Bone Erosion in Rheumatoid Arthritis Patients

bone mask generation from 3d slicer generated file and statistical analysis of identified bone erosion in rheumatoid arthritis patients

Identification of Bone Erosions in HR-pQCT Images in Rheumatoid Arthritis

Bone erosions occur when inflammation causes localized bone loss at the cortical bone surface. These erosions extend into the underlying trabecular bone region. They are a pathological feature of several forms of inflammatory arthritis, including rheumatoid arthritis (RA)1. Erosion presence and size are associated with poor outcomes, patient function, and disease progression2,3,4,5. While plain radiography remains the clinical standard for erosion assessment, high-resolution peripheral quantitative computed tomography (HR-pQCT) provides 3D images and superior sensitivity and specificity for erosion detection6,7. For inflammatory arthritis, such as RA, HR-pQCT is commonly performed on the 2nd and 3rd metacarpophalangeal joints - the most affected joints of the hand8. Because HR-pQCT images have high spatial resolution, physiological interruptions in the cortical surface are also observed in healthy individuals without RA9. These cortical interruptions are often associated with vascular channels or nutrient foramen passing through the bone10. Thus, the challenge is to distinguish cortical interruptions associated with a disease process (i.e., pathological erosions) from non-pathological features.
The consensus definition of a pathological bone erosion was published by the Study grouP for xtrEme Computed Tomography in Rheumatoid Arthritis (SPECTRA) as the presence of a definite interruption in the cortical layer of the bone that extends over at least two consecutive slices and is detectable in two or more perpendicular planes11. Further, the interruption must be non-linear in shape and accompanied by a loss in the trabecular region. Visual examples of cortical interruptions that do and do not meet the criteria of erosions are shown in Klose-Jensen et al.12.
However, not all cortical interruptions that meet the above criteria are classified as erosions. Interruptions are sometimes caused by physiological processes such as vascular channels (Figure 1). These can be identified and differentiated from erosions due to their predictable anatomical locations, parallel and straight margins and sub-millimetric size13. Cysts are another form of cortical interruption that is not considered to be an erosion. They often have a rounded trabecular structure with a clear cystic wall 13. In contrast to the sharp edges and open trabecular structure displayed by erosions. However, it is possible for erosions to form within cystic sites, making it ambiguous to delineate the volume of bone loss caused by the erosions and not the cysts. While resolving this ambiguity with further criteria is not the purpose of this study, there is a need to provide comprehensive examples of pathological erosion and physiological cortical interruptions.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/65802/65802fig01.jpg" /> 
Figure 1: Example of cortical interruptions that were not caused solely by erosions. (A) A drawing illustrating the common location of vascular channels at the base of the metacarpal head. Examples of vascular channels in (B) coronal, (C) sagittal, (D) and (E) axial planes. (F) Example of a cortical interruption caused by a cyst. (G) Example of a void volume within trabecular region of the bone involving both cysts and erosions. <a href="https://www.jove.com/files/ftp_upload/65802/65802fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
Despite the challenges in erosion identification, there are currently no training tools in place to provide less experienced users with guidance on interpreting HR-pQCT images for erosion analysis. Recently, an open-source module for erosion analysis called bone analysis module (BAM) - Erosion Volume was developed, implemented as an extension to an open-source image processing software to enable erosion visualization and volumetric analyses14. The protocol presented here describes the use of a training module added to BAM (BAM - Training), which compares a users&#39; erosion identification attempts by comparing the erosion identification with erosions annotated by expert rheumatologists. This training tool provides users with feedback on erosion identification in order to guide improvements in erosion analysis. Software installation instructions are provided in step 1. For new data acquisition, see steps 3 - 5.3. For training module use only, see step 2.

Author Spotlight: Enhancing Rheumatoid Arthritis Research Through HR-pQCT Imaging Analysis 

Erosion Identification in Metacarpophalangeal Joints in Rheumatoid Arthritis using High-Resolution Peripheral Quantitative Computed Tomography

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Bone Mask Generation from 3D Slicer Generated File and Statistical Analysis of Identified Bone Erosion in Rheumatoid Arthritis Patients  

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214 Views. Bone Mask Generation from 3D Slicer Generated File and Statistical Analysis of Identified Bone Erosion in Rheumatoid Arthritis Patients

Video: Bone Mask Generation from 3D Slicer Generated File and Statistical Analysis of Identified Bone Erosion in Rheumatoid Arthritis Patients  

Bone erosions are a pathological feature of several forms of inflammatory arthritis including rheumatoid arthritis (RA). The increased presence and size of erosions are associated with poor outcomes, joint function, and disease progression. High-resolution peripheral quantitative computed tomography (HR-pQCT) provides unparalleled in vivo visualization of bone erosions. However, at this resolution, discontinuities in the cortical shell (cortical breaks) that are associated with normal physiological processes and pathology are also visible. The Study grouP for xtrEme Computed Tomography in Rheumatoid Arthritis previously used a consensus process to develop a definition of pathological erosion in HR-pQCT: a cortical break detected in at least two consecutive slices, in at least two perpendicular planes, non-linear in shape, with underlying trabecular bone loss. However, despite the availability of a consensus definition, erosion identification is a demanding task with challenges in inter-rater variability. The purpose of this work is to introduce a training tool to provide users with guidance on identifying pathological cortical breaks on HR-pQCT images for erosion analysis. The protocol presented here uses a custom-built module (Bone Analysis Module (BAM) - Training), implemented as an extension to an open-source image processing software (3D Slicer). Using this module, users can practice identifying erosions and compare their results to erosions annotated by expert rheumatologists.

Bone erosions are an important pathological feature of rheumatoid arthritis. The purpose of this work is to introduce a training tool to provide users with guidance on identifying pathological cortical breaks on high resolution peripheral quantitative computed tomography images for erosion analysis.

Bone erosions are a pathological feature of several forms of inflammatory arthritis including rheumatoid arthritis (RA). The increased presence and size ...