False-positive helical CT findings of multifocal and multicentric breast cancer: is attenuation of tumor useful for diagnosing enhanced lesions?

Breast Cancer. 2002;9(1):62-8. doi: 10.1007/BF02967549.


Objective: To analyze helical CT false-positive multifocal breast cancers and to assess the relevance of the attenuation of tumors for diagnosing enhanced lesions.

Methods: Helical CT studies of 156 invasive breast cancers before breast conserving surgery were examined. A lesion was defined as positive if focal enhancement was detected by CT within 100 seconds after contrast material administration. The attenuation and enhancement percent ratio [(post-contrast value/pre-contrast value)%] were obtained. Attenuation of false-positive and malignant lesions was compared.

Results: Helical CT enabled the detection of all 156 invasive tumors with 95 intraductal tumor extensions. The sensitivity and specificity of multifocal/multicentric disease detection by helical CT were 69% and 90%, respectively. False-positive multifocal/multicentric findings were obtained in 11 (7%) of 156 cases. The mean value of the enhancement percent ratio of the index tumors was 237%. Significant differences in the attenuation on post-contrast enhanced scans between the enhanced lesions (index tumors; mean, 82 HU), the true-positive multifocal/multicentric lesions (mean, 73 HU), the false-positive multifocal/multicentric lesions (mean, 87 HU) and normal breast tissue (mean, 32 HU) were found (p<0.0001). The attenuation of the true-positive multifocal/multicentric lesions on post-contrast enhanced scans was significantly less than that of the false-positive multifocal/multicentric lesions (p=0.03).

Conclusion: Attenuation of tumor is not useful for differential diagnosis of enhanced lesions on helical CT of the breast. The presence of enhancement alone does not always indicate a malignant lesion.

Publication types

  • Evaluation Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biopsy, Needle
  • Breast Neoplasms / diagnostic imaging*
  • Breast Neoplasms / pathology
  • Breast Neoplasms / surgery
  • Carcinoma, Ductal, Breast / diagnostic imaging*
  • Carcinoma, Ductal, Breast / pathology
  • Carcinoma, Ductal, Breast / surgery
  • Contrast Media
  • False Positive Reactions
  • Female
  • Humans
  • Mastectomy, Segmental
  • Middle Aged
  • Neoplasm Staging
  • Predictive Value of Tests
  • Radiographic Image Enhancement
  • Sensitivity and Specificity
  • Tomography, X-Ray Computed / standards*


  • Contrast Media