An automated algorithm for the detection of cortical interruptions and its underlying loss of trabecular bone; a reproducibility study

Abstract

BackgroundWe developed a semi-automated algorithm that detects cortical interruptions in finger joints using high-resolution peripheral quantitative computed tomography (HR-pQCT), and extended it with trabecular void volume measurement. In this study we tested the reproducibility of the algorithm using scan/re-scan data.MethodsSecond and third metacarpophalangeal joints of 21 subjects (mean age 49 (SD 11) years, 17 early rheumatoid arthritis and 4 undifferentiated arthritis, all diagnosed < 1 year ago) were imaged twice by HR-pQCT on the same day with repositioning between scans. The images were analyzed twice by one operator (OP1) and once by an additional operator (OP2), who independently corrected the bone contours when necessary. The number, surface and volume of interruptions per joint were obtained. Intra- and inter-operator reliability and intra-operator reproducibility were determined by intra-class correlation coefficients (ICC). Intra-operator reproducibility errors were determined as the least significant change (LSCSD).ResultsPer joint, the mean number of interruptions was 3.1 (SD 3.6), mean interruption surface 4.2 (SD 7.2) mm2, and mean interruption volume 3.5 (SD 10.6) mm3 for OP1. Intra- and inter-operator reliability was excellent for the cortical interruption parameters (ICC ≥0.91), except good for the inter-operator reliability of the interruption surface (ICC = 0.70). The LSCSD per joint was 4.2 for the number of interruptions, 5.8 mm2 for interruption surface, and 3.2 mm3 for interruption volume.ConclusionsThe algorithm was highly reproducible in the detection of cortical interruptions and their volume. Based on the LSC findings, the potential value of this algorithm for monitoring structural damage in the joints in early arthritis patients needs to be tested in clinical studies.Electronic supplementary materialThe online version of this article (10.1186/s12880-018-0255-7) contains supplementary material, which is available to authorized users.

High-Resolution Peripheral Quantitative Computed Tomography for Bone Evaluation in Inflammatory Rheumatic Disease

“…However, manual scoring is laborious and requires substantial training and standardization. An automated detection algorithm has been developed, named the Cortical Interruption Detection Algorithm (39,40,52,53,64). The Cortical Interruption Detection Algorithm detects the presence of cortical interruptions, directing the reader to lesion locations to verify that they meet the erosion definition as opposed to those that merely represent physiological breaks in the cortical bone, i.e., vascular channels ( Figure 4A) or stack misalignment ( Figure 4B) and osteophyte formation ( Figure 4C).…”

“…Forty-six publications characterizing erosions or cortical breaks/interruptions were found. Erosions have been assessed in a variety of arthritic conditions including early inflammatory arthritis ( 3 , 33 , 37 , 53 , 58 , 59 , 67 ), RA ( 1 , 3 – 7 , 9 , 10 , 12 , 15 , 23 , 26 , 28 – 30 , 34 , 39 , 40 , 44 , 46 – 48 , 52 , 54 , 55 , 61 , 64 , 65 , 67 ), PsA ( 5 , 7 , 14 , 49 , 61 , 66 , 69 ), and erosive hand OA ( 21 ), as well as healthy controls ( 3 , 5 , 7 , 16 , 33 , 39 , 40 , 44 , 45 , 52 , 54 , 55 , 60 , 61 , 64 , 67 ) and subjects with ACPA antibodies but no features of arthritis ( 32 , 50 , 62 ).…”

“…More recently, semi-automated and automated algorithms have been introduced. These include Medical Image Analysis Framework (MIAF) (custom software developed at the University of Erlangen; Figure 6B ) ( 23 , 29 ), modified Evaluation Script for Erosions (mESE; using Image Processing Language, Scanco Medical) ( 47 ), Cortical Interruption Detection Algorithm (custom analysis developed at Maastricht University and Eindhoven University of Technology using Image Processing Language, Scanco Medical; Figure 7 ) ( 39 , 40 , 52 , 53 , 64 ) and a surface transformation algorithm (custom software developed at Worcester Polytechnic Institute; Figure 8 ) ( 61 ). MIAF, mESE, and the Cortical Interruption Detection Algorithm perform a segmentation of the bone and an estimation of the location of the cortical break.…”

Multi-Modal Imaging to Assess the Interaction Between Inflammation and Bone Damage Progression in Inflammatory Arthritis

“…HR-pQCT allows for the resolution of individual trabeculae (4), and the ability to quantitatively evaluate joint properties. Semi-automated techniques have been developed to assess periarticular bone mineral density and microarchitecture, joint space width as well as erosion volume (5)(6)(7)(8). An overview of these techniques is provided in a review by Klose-Jensen et al (9) in this special issue.…”

The utility of multi-stack alignment and 3D longitudinal image registration to assess bone remodeling in rheumatoid arthritis patients from second generation HR-pQCT scans

“…The high spatial resolution provided by HR-pQCT enables the analysis and quantification of small erosions, which are clinically significant as it has been shown that patients with RA have a greater number of small erosions compared to healthy controls [8], and have shown to have an association with pain and decreases in function [9]. Erosion volume has been calculated using manual, semi-automated and fully-automated tools with high reproducibility [10][11][12].…”