Conspicuity of microcalcifications on digital screening mammograms using varying degrees of monitor zooming.
OBJECTIVE
American College of Radiology guidelines suggest that digital screening mammographic images should be viewed at the full resolution at which they were acquired. This slows interpretation speed. The aim of this study was to examine the effect of various levels of zooming on the detection and conspicuity of microcalcifications.


METHODS
Six radiologists viewed 40 mammographic images five times in different random orders using five different levels of zooming: full resolution (100%) and 30%, 61%, 88%, and 126% of that size. Thirty-three images contained microcalcifications varying in subtlety, all associated with breast cancer. The clusters were circled. Seven images contained no malignant calcifications but also had randomly placed circles. The radiologists graded the presence or absence and visual conspicuity of any calcifications compared to calcifications in a reference image. They also counted the microcalcifications.


RESULTS
The radiologists saw the microcalcifications in 94% of the images at 30% size and in either 99% or 100% of the other tested levels of zooming. Conspicuity ratings were worst for the 30% size and fairly similar for the others. Using the 30% size, two radiologists failed to see the microcalcifications on either the craniocaudal or mediolateral oblique view taken from one patient. Interobserver agreement regarding the number of calcifications was lowest for the 30% images and second lowest for the 100% images.


CONCLUSIONS
Images at 30% size should not be relied on alone for systematic scanning for microcalcifications. The other four levels of magnification all performed well enough to warrant further testing.
Haygood
Tamara Miner
TM
Department of Diagnostic Radiology, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 1273, Houston, TX 77030-4009, USA. tamara.haygood@mdanderson.org
Arribas
Elsa
E
Brennan
Patrick C
PC
Atkinson
E Neely
EN
Herndon
Mark
M
Dieber
Joseph
J
Geiser
William
W
Santiago
Lumarie
L
Mills
Chadwick M
CM
Davis
Paul
P
Adrada
Beatriz
B
Carkaci
Selin
S
Stephens
Tanya W
TW
Whitman
Gary J
GJ
D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D002114:Calcinosis / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D008403:Mass Screening / Q000379:methods*; D011230:Precancerous Conditions / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity