Rates and causes of disagreement in interpretation of full-field digital mammography and film-screen mammography in a diagnostic setting.
OBJECTIVE
This study was performed to determine the rates and causes of disagreements in interpretation between full-field digital mammography and film-screen mammography in a diagnostic setting.


METHODS
Patients undergoing diagnostic mammography were invited to participate in the digital mammography study. Three views, selected by the radiologist interpreting the film-screen mammography, were obtained in both film-screen mammography and digital mammography. Radiologists independently assigned a Breast Imaging Reporting and Data System (BI-RADS) category to the film-screen mammography and the digital mammography images. The BI-RADS categories were grouped into the general categories of agreement, partial agreement, or disagreement. A third and different radiologist reviewed all cases of disagreement, reached a decision as to management, and determined the primary cause of disagreement.


RESULTS
Six radiologists reviewed digital mammography and film-screen mammography diagnostic images in a total of 1147 breasts in 692 patients. Agreement between digital mammography and final film-screen mammography assessment was present in 937 breasts (82%), partial agreement in 159 (14%), and disagreement in 51 (4%), for a kappa value of 0.29. The primary causes of disagreement were differences in management approach of the radiologists (52%), information derived from sonography or additional film-screen mammograms (34%), and technical differences between the two mammographic techniques (10%).


CONCLUSIONS
Significant disagreement between film-screen mammography and digital mammography affecting follow-up management was present in only 4% of breasts. The most frequent cause of disagreement in interpretation was a difference in management approach between radiologists (interobserver variability). This source of variability was larger than that due to differences in lesion visibility between film-screen mammography and digital mammography.
Venta
L A
LA
Radiology Department, Lynn Sage Comprehensive Breast Center, Northwestern University Medical School, Galter Pavilion, 13th Floor, 251 E. Huron St., Chicago, IL 60611-2923, USA.
Hendrick
R E
RE
Adler
Y T
YT
DeLeon
P
P
Mengoni
P M
PM
Scharl
A M
AM
Comstock
C E
CE
Hansen
L
L
Kay
N
N
Coveler
A
A
Cutter
G
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008327:Mammography / Q000706:statistics & numerical data*; D008875:Middle Aged; D015588:Observer Variation; D012815:Signal Processing, Computer-Assisted; D014962:X-Ray Film