title: Automatic Quantification of Radiographic Wrist Joint Space Width of Patients With Rheumatoid Arthritis.
abstract: Objective:Wrist joint space narrowing is a main radiographic outcome of rheumatoid arthritis (RA). Yet, automatic radiographic wrist joint space width (JSW) quantification for RA patients has not been widely investigated. The aim of this paper is to present an automatic method to quantify the JSW of three wrist joints that are least affected by bone overlapping and are frequently involved in RA. These joints are located around the scaphoid bone, viz. the multangular-navicular, capitate-navicular-lunate, and radiocarpal joints.Methods:The joint space around the scaphoid bone is detected by using consecutive searches of separate path segments, where each segment location aids in constraining the subsequent one. For joint margin delineation, first the boundary not affected by X-ray projection is extracted, followed by a backtrace process to obtain the actual joint margin. The accuracy of the quantified JSW is evaluated by comparison with the manually obtained ground truth.Results:Two of the 50 radiographs used for evaluation of the method did not yield a correct path through all three wrist joints. The delineated joint margins of the remaining 48 radiographs were used for JSW quantification. It was found that 90% of the joints had a JSW deviating less than 20% from the mean JSW of manual indications, with the mean JSW error less than 10%.Conclusion:The proposed method is able to automatically quantify the JSW of radiographic wrist joints reliably.
  
  
  
  The proposed method may aid clinical researchers to study the progression of wrist joint damage in RA studies.Objective:Wrist joint space narrowing is a main radiographic outcome of rheumatoid arthritis (RA). Yet, automatic radiographic wrist joint space width (JSW) quantification for RA patients has not been widely investigated. The aim of this paper is to present an automatic method to quantify the JSW of three wrist joints that are least affected by bone overlapping and are frequently involved in RA. These joints are located around the scaphoid bone, viz. the multangular-navicular, capitate-navicular-lunate, and radiocarpal joints.Methods:The joint space around the scaphoid bone is detected by using consecutive searches of separate path segments, where each segment location aids in constraining the subsequent one. For joint margin delineation, first the boundary not affected by X-ray projection is extracted, followed by a backtrace process to obtain the actual joint margin. The accuracy of the quantified JSW is evaluated by comparison with the manually obtained ground truth.Results:Two of the 50 radiographs used for evaluation of the method did not yield a correct path through all three wrist joints. The delineated joint margins of the remaining 48 radiographs were used for JSW quantification. It was found that 90% of the joints had a JSW deviating less than 20% from the mean JSW of manual indications, with the mean JSW error less than 10%.Conclusion:The proposed method is able to automatically quantify the JSW of radiographic wrist joints reliably.
  
  
  
  The proposed method may aid clinical researchers to study the progression of wrist joint damage in RA studies.
authors.affiliation: Image Sciences Institute, University Medical Center Utrecht, Utrecht 3584, CX, The Netherlands.
authors.forename: Yinghe
authors.initials: Y
authors.lastname: Huo
authors.affiliation: Image Sciences InstituteUniversity Medical Center Utrecht.
authors.forename: Koen L
authors.initials: KL
authors.lastname: Vincken
authors.affiliation: Department of RheumatologyLeiden University Medical Center.
authors.forename: Desiree
authors.initials: D
authors.lastname: van der Heijde
authors.affiliation: Department of Rheumatology and Clinical ImmunologyUniversity Medical Center Utrecht.
authors.forename: Maria J H
authors.initials: MJH
authors.lastname: de Hair
authors.affiliation: Department of Rheumatology and Clinical ImmunologyUniversity Medical Center Utrecht.
authors.forename: Floris P
authors.initials: FP
authors.lastname: Lafeber
authors.affiliation: Image Sciences InstituteUniversity Medical Center Utrecht.
authors.forename: Max A
authors.initials: MA
authors.lastname: Viergever
mesh_terms: D000465:Algorithms; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging*; D006801:Humans; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D011859:Radiography; D014955:Wrist Joint / Q000000981:diagnostic imaging*
keywords: Bones; Diagnostic radiography; Feature extraction; Indexes; Joints; Wrist