Breast MRI Findings: Kinetics

by Michael Roubakha, MD, and Cheryce Fischer, MD

  • Refers to breast lesion enhancement curves, also kown as Kuhl enhancement curves
  • In addition to the margins of a lesion, the enhancement intensity of a lesion on MRI two minutes or less after contrast administration is the most important feature for lesion diagnosis
  • The next most important feature is the qualitative assessment of the enhancement curve1
MRI findings

There are three possible intial phase curves (in order of least to most concerning):

  1. Slow
  2. Medium
  3. Rapid

There are also three possible late phase curves (in order of least to most concerning):

Type I: Progressive pattern

  • Continued increase in signal intensity over time
  • Usually a benign pattern (83% of lesions)
  • Only about 9% of lesions are malignant2
  • Sensitivity of 52.2% and specificity of 71%3

Type II: Plateau pattern

  • Initial uptake followed by leveling off of signal intensity
  • Suggestive of malignancy (sensitivity of 42.6% and specificity of 75% for malignancy)3

Type III: Washout pattern

  • Initial uptake followed by reduced enhancement
  • Strongly suggestive of malignancy (specificity of 90.4% and sensitivity of 20.5%)3

Finally, a lack of enhancement does not completely exlcude in situ or invasive cancer.

References

  1. Macura KJ, Ouwerkerk R, Jacobs MA, Bluemke DA. "Patterns of Enhancement on Breast MR Images: Interpretation and Imaging Pitfalls." RadioGraphics 2006;26(6):1719-1734. DOI:10.1148/rg.266065025
  2. Kuhl CK, Mielcareck P, Klaschik S, et al. "Dynamic breast MR imaging: are signal intensity time course data useful for differential diagnosis of enhancing lesions?" Radiology 1999;211:101–110. DOI: 10.1148/radiology.211.1.r99ap38101
  3. Bluemke DA, Gatsonis CA, Chen MH, et al. "Magnetic resonance imaging of the breast prior to biopsy." JAMA 2004;292:2735–2742.  DOI: 10.1001/jama.292.22.2735