Multi-dimensional reliability assessment of fractal signature analysis in an outpatient sports medicine population.
The aim of this study has been to test reproducibility of fractal signature analysis (FSA) in a young, active patient population taking into account several parameters including intra- and inter-reader placement of regions of interest (ROIs) as well as various aspects of projection geometry. In total, 685 patients were included (135 athletes and 550 non-athletes, 18-36 years old). Regions of interest (ROI) were situated beneath the medial tibial plateau. The reproducibility of texture parameters was evaluated using intraclass correlation coefficients (ICC). Multi-dimensional assessment included: (1) anterior-posterior (A.P.) vs. posterior-anterior (P.A.) (Lyon-Schuss technique) views on 102 knees; (2) unilateral (single knee) vs. bilateral (both knees) acquisition on 27 knees (acquisition technique otherwise identical; same A.P. or P.A. view); (3) repetition of the same image acquisition on 46 knees (same A.P. or P.A. view, and same unitlateral or bilateral acquisition); and (4) intra- and inter-reader reliability with repeated placement of the ROIs in the subchondral bone area on 99 randomly chosen knees. ICC values on the reproducibility of texture parameters for A.P. vs. P.A. image acquisitions for horizontal and vertical dimensions combined were 0.72 (95% confidence interval (CI) 0.70-0.74) ranging from 0.47 to 0.81 for the different dimensions. For unilateral vs. bilateral image acquisitions, the ICCs were 0.79 (95% CI 0.76-0.82) ranging from 0.55 to 0.88. For the repetition of the identical view, the ICCs were 0.82 (95% CI 0.80-0.84) ranging from 0.67 to 0.85. Intra-reader reliability was 0.93 (95% CI 0.92-0.94) and inter-observer reliability was 0.96 (95% CI 0.88-0.99). A decrease in reliability was observed with increasing voxel sizes. Our study confirms excellent intra- and inter-reader reliability for FSA, however, results seem to be affected by acquisition technique, which has not been previously recognized.
Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar; Quantitative Imaging Center (QIC), Department of Radiology, Boston University School of Medicine, Boston, MA, USA; Department of Radiology, Mercy Catholic Medical Center, Darby, PA, USA.
Mohamed
M
Jarraya
Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar; Quantitative Imaging Center (QIC), Department of Radiology, Boston University School of Medicine, Boston, MA, USA.
Ali
A
Guermazi
Clinical Epidemiology and Training Unit, Department of Medicine, Boston University School of Medicine, Boston, MA, USA.
Jingbo
J
Niu
Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
Jeffrey
J
Duryea
Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA.
John A
JA
Lynch
Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar; Quantitative Imaging Center (QIC), Department of Radiology, Boston University School of Medicine, Boston, MA, USA; Department of Radiology, University of Erlangen-Nuremberg, Erlangen, Germany. Electronic address: frank.roemer@aspetar.com.
Frank W
FW
Roemer
D000293:Adolescent; D000328:Adult; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D017709:Fractals; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007717:Knee / Q000000981:diagnostic imaging / Q000473:pathology; D007866:Leg / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000473:pathology; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000473:pathology; D010045:Outpatients; D011859:Radiography; D015203:Reproducibility of Results; D012916:Soccer; D013178:Sports Medicine; D055815:Young Adult
Fractal signature analysis; Knee; Osteoarthritis; Radiography; Reproducibility