Larsen scoring of digitized X-ray images.
OBJECTIVE
To determine how Larsen scores from digitized X-rays compare to those from film originals.


METHODS
A hundred sets of radiographs of patients recruited with early rheumatoid arthritis (RA) were assessed using the Larsen scoring system. Digitized copies of these sets were then viewed on a computer screen and scored according to Larsen in a random order. The quality of the digitized image was also recorded. For each set of X-rays, the signed difference between the score from film and the score from the digitized images was calculated.


RESULTS
A total of 95% of the digitized X-ray sets were scored successfully; 5% were not scored due to the images being unreadable. The mean difference between the two sets of scores was -1.2 (95% CI [-2.06, -0.37]). There was no trend in the difference with respect to the mean of the two scores (P>0.1).


CONCLUSIONS
The Larsen scoring of digitized X-ray images has been validated.
Solymossy
C
C
Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, Clinical Operational Research Unit, University College London, UK.
Dixey
J
J
Utley
M
M
Gallivan
S
S
Young
A
A
Cox
N
N
Davies
P
P
Emery
P
P
Gough
A
A
James
D
D
Prouse
P
P
Williams
P
P
Winfield
J
J
D000703:Analog-Digital Conversion; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement; D012720:Severity of Illness Index