Effect of Breast Density on Computer Aided Detection

Purpose: This study was conducted to assess the clinical impact of breast density and density of the lesion’s background on the performance of a computer-aided detection (CAD) system in the detection of breast masses (MA) and microcalcifications (MC). Materials and Methods: A total of 200 screening mammograms interpreted as BI-RADS 1 and suspicious mammograms of 150 patients having a histologically verified malignancy from 1992 to 2000 were selected by using a sampler of tumor cases. Excluding those cases having more than one lesion or a contralateral malignancy attributable to statistical reasons, 127 cases with 127 malignant findings were analyzed with a CAD system (Second Look 5.0, CADx Systems, Inc., Beavercreek, OH). Of the 127 malignant lesions, 56 presented as MC and 101 presented as MA, including 30 cases with both malignant signs. Overall breast density of the mammogram and density of the lesion’s background were determined by two observers in congruence (density a: entirely fatty, density b: scattered fibroglandular tissue, density c: heterogeneously dense, density d: extremely dense). Results: Within the unsuspicious group, 100/200 cases did not have any CAD MA marks and were therefore truly negative (specificity 50%), and 151/200 cases did not have any CAD MC marks (specificity 75.5%). For these 200 cases, the numbers of marks per image were 0.41 and 0.37 (density a), 0.38 and 0.97 (density b), 0.44 and 0.91 (density c), and 0.58 and 0.68 (density d) for MC and MA marks, respectively (Fisher’s t-test: n.s. for MC, p < 0.05 for MA). Malignant lesions were correctly detected in at least one view by the CAD system for 52/56 (92.8%) MC and 91/101 (90.1%) MA. Detection rate versus breast density was: 4/6 (66.7%) and 18/19 (94.7%) (density a), 32/33 (97.0%) and 49/51 (96.1%) (density b), 14/15 (93.3%) and 23/28 (82.1%) (density c), and 2/2 (100%) and 1/3 (33.3%) (density d) for MC and MA, respectively. Detection rate versus the lesion’s background was: 19/21 (90.5%) and 36/38 (94.7%) (density a), 34/36 (94.4%) and 59/62 (95.2%) (density b), 8/9 (88.9%) and 20/24 (83.3%) (density c), and 9/10 (90%) and 4/8 (50%) (density d) for groups 2 and 3, respectively. Detection rates differed significantly for masses in heterogeneously dense and extremely dense tissue (overall or lesion’s background) versus all other densities (Fisher’s t-test: p < 0.05). A significantly lowered FP rate for masses was found on mammograms of entirely fatty tissue. Conclusion: Overall breast density and density at a lesion’s background do not appear to have a significant effect on CAD sensitivity or specificity for MC. CAD sensitivity for MA may be lowered in cases with heterogeneously and extremely dense breasts, and CAD specificity for MA is highest in cases with extremely fatty breasts. The effects of overall breast density and density of a lesion’s background appear to be similar.

[1]  L. Tabár,et al.  Potential contribution of computer-aided detection to the sensitivity of screening mammography. , 2000, Radiology.

[2]  T. Freer,et al.  Screening mammography with computer-aided detection: prospective study of 12,860 patients in a community breast center. , 2001, Radiology.

[3]  Thomas Boehm,et al.  Influence of breast lesion size and histologic findings on tumor detection rate of a computer-aided detection system. , 2003, Radiology.

[4]  [Evaluation of the primary diagnosis with a CAD-system in mammography]. , 2003, RoFo : Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin.

[5]  K Doi,et al.  Effect of case selection on the performance of computer-aided detection schemes. , 1994, Medical physics.

[6]  Ansgar Malich,et al.  Are unnecessary follow-up procedures induced by computer-aided diagnosis (CAD) in mammography? Comparison of mammographic diagnosis with and without use of CAD. , 2004, European journal of radiology.

[7]  N. Petrick,et al.  Improvement of radiologists' characterization of mammographic masses by using computer-aided diagnosis: an ROC study. , 1999, Radiology.

[8]  Marco Zappa,et al.  Comparison of standard reading and computer aided diagnosis (CAD) on a proficiency test of screening mammography. , 2003, La Radiologia medica.

[9]  H. Sittek,et al.  Computer-aided diagnosis in mammography , 1997, Der Radiologe.

[10]  C. Thng,et al.  Radiologists' detection of mammographic abnormalities with and without a computer-aided detection system. , 2003, Australasian radiology.

[11]  Thomas Boehm,et al.  Tumour detection rate of a new commercially available computer-aided detection system , 2001, European Radiology.

[12]  Y H Chang,et al.  Computer-aided detection of clustered microcalcifications on digitized mammograms: a robustness experiment. , 1997, Academic radiology.

[13]  G Wolf,et al.  [Computer-assisted diagnosis in mammography: the R2 ImageChecker System in detection of spiculated lesions]. , 1998, Wiener medizinische Wochenschrift.

[14]  Baudouin Maldague,et al.  Mammography and subsequent whole-breast sonography of nonpalpable breast cancers: the importance of radiologic breast density. , 2003, AJR. American journal of roentgenology.

[15]  F. Winsberg,et al.  Detection of Radiographic Abnormalities in Mammograms by Means of Optical Scanning and Computer Analysis , 1967 .

[16]  D. Ikeda,et al.  Mammographic characteristics of 115 missed cancers later detected with screening mammography and the potential utility of computer-aided detection. , 2001, Radiology.

[17]  S. Feig.  Breast Cancer Screening: Potential Role of Computer-Aided Detection (CAD) , 2002, Technology in cancer research & treatment.

[18]  Rachel F Brem,et al.  Improvement in sensitivity of screening mammography with computer-aided detection: a multiinstitutional trial. , 2003, AJR. American journal of roentgenology.

[19]  R. Bird.  Professional quality assurance for mammography screening programs. , 1990, Radiology.

[20]  K Doi,et al.  Improvement in radiologists' detection of clustered microcalcifications on mammograms. The potential of computer-aided diagnosis. , 1990, Investigative radiology.

[21]  W. T. Ho,et al.  Clinical performance of computer-assisted detection (CAD system in detecting carcinoma in breasts of different densities. , 2003, Clinical radiology.

[22]  Maryellen L. Giger,et al.  Computer-Aided Diagnosis in Mammography , 2000 .

[23]  Y H Chang,et al.  Computer-aided detection of clustered microcalcifications in digitized mammograms. , 1995, Academic radiology.

[24]  Guy Marchal,et al.  COMPUTER-ASSISTED DIAGNOSIS , 1989, The Lancet.

[25]  Martin P DeSimio,et al.  Determining efficacy of mammographic CAD systems. , 2002, Journal of digital imaging.

[26]  E. Thurfjell,et al.  Benefit of independent double reading in a population-based mammography screening program. , 1994, Radiology.