[Clinical value of computer-assisted analysis in MR mammography. A comparison between two systems and three observers with different levels of experience].
OBJECTIVE
The value of computer-assisted detection (CAD) used in magnetic resonance (MR) mammography in a clinical setting is currently a subject of controversy. This study evaluated the extent to which color-coded CAD systems aid radiologists with different levels of experience in their reading of MR mammographies.


METHODS
In this prospective study, 48 patients with a total of 88 lesions (43 malignant, 45 benign) were included. All examinations were performed on a 1.5 Tesla MR scanner with intravenous application of 0.1 mmol gadopentetate dimeglumine/kg body weight. Three readers independently analyzed the images without knowledge of the clinical data; radiologists 1 and 2 were much more experienced in the interpretation of MR mammographies than radiologist 3. Initially, the observers visually categorized the lesions as benign or malignant following classification of BI-RADS (Breast Imaging Reporting and Data System). The readers also scored their own confidence level using a dichotome score (1: unsure vs. 2: sure) according to the BI-RADS classification. The images were then analyzed in a blinded manner with two technically different CAD systems: the full-time point (FTP) method (Cadsciences; White Plains, NY, USA) and the Dynacad version 1.1 (Invivo; Pewaukee, WI, USA).


RESULTS
After CAD, all three readers classified more malignant lesions as BI-RADS 4 or 5 (suspicious or highly suggestive of malignancy). However, this increase in sensitivity revealed only statistical significance for observer 3 (p < 0.05). After CAD, the two experienced readers categorized about the same quantity of benign lesions correctly as BI-RADS 2. Observer 3 classified less benign lesions as BI-RADS 2 after both CAD analyses; i. e. the specificity decreased. The subjective confidence of all observers increased after analysis with Dynacad. Observer 3 also reported to be more confident after the FTP method.


CONCLUSIONS
Computer-assisted detection can be a useful additional diagnostic tool for the radiologist in the interpretation of MR mammographies, but does not have the potential to replace the professional experience of a radiologist.
Institut für Diagnostische und Interventionelle Radiologie, Friedrich-Schiller-Universität Jena. dianerenz@yahoo.de
D M
DM
Renz
P A T
PA
Baltzer
P E
PE
Kullnig
J
J
Böttcher
T
T
Vag
M
M
Gajda
O
O
Camara
I B
IB
Runnebaum
W A
WA
Kaiser
D001941:Breast Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003936:Diagnosis, Computer-Assisted / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008327:Mammography / Q000379:methods*; D015588:Observer Variation; D011446:Prospective Studies
Klinische Wertigkeit computergestützter Analysen in der MR-Mammografie. Ein Vergleich zwischen zwei Systemen und drei Untersuchern mit unterschiedlicher Erfahrung.