Effect of menstrual cycle phase on background parenchymal uptake at molecular breast imaging

Acad Radiol. 2015 Sep;22(9):1147-56. doi: 10.1016/j.acra.2015.04.003. Epub 2015 Jun 22.


Rationale and objectives: The level of Tc-99m sestamibi uptake within normal fibroglandular tissue on molecular breast imaging (MBI), termed background parenchymal uptake (BPU), has been anecdotally observed to fluctuate with menstrual cycle. Our objective was to assess the impact of menstrual cycle phase on BPU appearance.

Materials and methods: Premenopausal volunteers who reported regular menstrual cycles and no exogenous hormone use were recruited to undergo serial MBI examinations during the follicular and luteal phase. A study radiologist, blinded to cycle phase, categorized BPU as photopenic, minimal mild, moderate, or marked. Change in BPU with cycle phase was determined, as well as correlations of BPU with mammographic density and hormone levels.

Results: In 42 analyzable participants, high BPU (moderate or marked) was observed more often in luteal phase compared to follicular (P = .016). BPU did not change with phase in 30 of 42 participants (71%) and increased in the luteal phase compared to follicular in 12 (29%). High BPU was more frequent in dense breasts compared to nondense breasts at both the luteal (58% [15 of 26] vs. 13% [2 of 16], P = .004) and follicular phases (35% [9 of 26] vs. 6% [1 of 16], P = .061). Spearman correlation coefficients did not show any correlation of BPU with hormone levels measured at either cycle phase and suggested a weak correlation between change in BPU and changes in estrone and estradiol between phases.

Conclusions: We observed variable effects of menstrual cycle on BPU among our cohort of premenopausal women; however, when high BPU was observed, it was most frequently seen during the luteal phase compared to follicular phase and in women with dense breasts compared to nondense breasts.

Keywords: Molecular breast imaging; background parenchymal uptake; hormones; menstrual cycle.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Breast / diagnostic imaging*
  • Breast Density / physiology
  • Chromatography, Liquid / methods
  • Cohort Studies
  • Estradiol / blood
  • Estrone / blood
  • Female
  • Follicle Stimulating Hormone / blood
  • Follicular Phase / physiology*
  • Humans
  • Luteal Phase / physiology*
  • Mammography / methods
  • Middle Aged
  • Molecular Imaging / methods*
  • Premenopause / physiology
  • Progesterone / blood
  • Prospective Studies
  • Radiopharmaceuticals*
  • Sex Hormone-Binding Globulin / analysis
  • Tandem Mass Spectrometry / methods
  • Technetium Tc 99m Sestamibi*
  • Testosterone / blood


  • Radiopharmaceuticals
  • Sex Hormone-Binding Globulin
  • Estrone
  • Testosterone
  • Progesterone
  • Estradiol
  • Follicle Stimulating Hormone
  • Technetium Tc 99m Sestamibi