Automatic radiographic quantification of hand osteoarthritis; accuracy and sensitivity to change in joint space width in a phantom and cadaver study

• Published in: Skeletal radiology 2012-01, Vol.41 (1), p.41-49
• Main Authors: Huétink, Kasper, van ’t Klooster, Ronald, Kaptein, Bart L., Watt, Iain, Kloppenburg, Margreet, Nelissen, Rob G. H. H., Reiber, Johan H. C., Stoel, Berend C.
• Format: Article
• Language: English
• Subjects: Algorithms; Cadaver; Cadavers; Comparative analysis; Data processing; Hand; Hand - diagnostic imaging; Humans; Imaging; Ionizing radiation; Joints; Measuring instruments; Medicine; Medicine & Public Health; Nuclear Medicine; Orthopedics; Osteoarthritis; Osteoarthritis - diagnostic imaging; Pathology; Pattern Recognition, Automated - methods; Phantoms, Imaging; Radiographic Image Enhancement - methods; Radiographic Image Interpretation, Computer-Assisted - methods; Radiography; Radiology; Reproducibility of Results; Scientific; Scientific Article; Sensitivity and Specificity
• ISSN: 0364-2348; 1432-2161
• DOI: 10.1007/s00256-011-1110-x

Objective To validate a newly developed quantification method that automatically detects and quantifies the joint space width (JSW) in hand radiographs. Repeatability, accuracy and sensitivity to changes in JSW were determined. The influence of joint location and joint shape on the measurements was tested. Methods A mechanical micrometer set-up was developed to define and adjust the true JSW in an acrylic phantom joint and in human cadaver-derived phalangeal joints. Radiographic measurements of the JSW were compared to the true JSW. Repeatability, systematic error (accuracy) and sensitivity (defined as the smallest detectable difference (SDD)) were determined. The influence of joint position on the JSW measurement was assessed by varying the location of the acrylic phantom on the X-ray detector with respect to the X-ray beam and the influence of joint shape was determined by using morphologically different human cadaver joints. Results The mean systematic error was 0.052 mm in the phantom joint and 0.210 mm in the cadaver experiment. In the phantom experiments, the repeatability was high (SDD = 0.028 mm), but differed slightly between joint locations ( p  = 0.046), and a change in JSW of 0.037 mm could be detected. Dependent of the joint shape in the cadaver hand, a change in JSW between 0.018 and 0.047 mm could be detected. Conclusions The automatic quantification method is sensitive to small changes in JSW. Considering the published data of JSW decline in the normal and osteoarthritic population, the first signs of OA progression with this method can be detected within 1 or 2 years.