Radiographic quantifications of joint space narrowing progression by computer-based approach using temporal subtraction in rheumatoid wrist.
OBJECTIVE
To investigate the validity of a computer-based method using temporal subtraction in carpal joints of patients with rheumatoid arthritis (RA), which can detect the difference in joint space between two images with the joint space difference index (JSDI).


METHODS
The study consisted of 43 patients with RA (39 females and 4 males) who underwent radiography at baseline and at 1-year follow-up. The joint space narrowing (JSN) of carpal joints on bilateral hand radiographs was assessed by our computer-based method, using the Sharp/van der Heijde method as the standard of reference. We compared the JSDI of joints with JSN progression in the follow-up period with that of those without JSN progression. In addition, we examined whether there is a significant difference in JSDI in terms of laterality or topology of the joint.


RESULTS
The JSDI of joints with JSN progression was significantly higher than that of those without JSN progression (Mann-Whitney U test, p < 0.001). There was no statistically significant difference in the JSDI between the left and right carpal joints, which was analysed for five different joints altogether and each joint separately (Mann-Whitney U test, p > 0.05). There was statistically significant difference in JSDI among different joints (Kruskal-Wallis test, p = 0.003).


CONCLUSIONS
These results suggest that our computer-based method may be useful to recognize the JSN progression on radiographs of rheumatoid wrists.


CONCLUSIONS
The computer-based temporal subtraction method can detect the JSN progression in the wrist, which is the single most commonly involved site in RA.
1 Graduate School of Health Sciences, Hokkaido University, Sapporo, Japan.
Shota
S
Ichikawa
2 Faculty of Health Sciences, Hokkaido University, Sapporo, Japan.
Tamotsu
T
Kamishima
3 Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
Kenneth
K
Sutherland
4 Katayama Orthopedic Rheumatology Clinic, Asahikawa, Japan.
Takanobu
T
Okubo
4 Katayama Orthopedic Rheumatology Clinic, Asahikawa, Japan.
Kou
K
Katayama
D000328:Adult; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014955:Wrist Joint / Q000000981:diagnostic imaging*