J Korean Soc Magn Reson Med.  2014 Mar;18(1):1-6. 10.13104/jksmrm.2014.18.1.1.

Estimation of T2* Relaxation Times for the Glandular Tissue and Fat of Breast at 3T MRI System

• Ryu JK
• Oh JH
• Kim HG
• Rhee SJ
• Seo M
• Jahng GH

• KMID: 1683774
• DOI: http://doi.org/10.13104/jksmrm.2014.18.1.1

Abstract

PURPOSE
T2* relaxation time which includes susceptibility information represents unique feature of tissue. The objective of this study was to investigate T2* relaxation times of the normal glandular tissue and fat of breast using a 3T MRI system.
MATERIALS AND METHODS
Seven-echo MR Images were acquired from 52 female subjects (age 49 +/- 12 years; range, 25 to 75) using a three-dimensional (3D) gradient-echo sequence. Echo times were between 2.28 ms to 25.72 ms in 3.91 ms steps. Voxel-based T2* relaxation times and R2* relaxation rate maps were calculated by using the linear curve fitting for each subject. The 3D regions-of-interest (ROI) of the normal glandular tissue and fat were drawn on the longest echo-time image to obtain T2* and R2* values. Mean values of those parameters were calculated over all subjects.
RESULTS
The 3D ROI sizes were 4818 +/- 4679 voxels and 1455 +/- 785 voxels for the normal glandular tissue and fat, respectively. The mean T2* values were 22.40 +/- 5.61 ms and 36.36 +/- 8.77 ms for normal glandular tissue and fat, respectively. The mean R2* values were 0.0524 +/- 0.0134/ms and 0.0297 +/- 0.0069/ms for the normal glandular tissue and fat, respectively.
CONCLUSION
T2* and R2* values were measured from human breast tissues. T2* of the normal glandular tissue was shorter than that of fat. Measurement of T2* relaxation time could be important to understand susceptibility effects in the breast cancer and the normal tissue.

Keyword

Breast; 3T MRI; T2star relaxation times

MeSH Terms

Breast Neoplasms
Breast*
Female
Humans
Magnetic Resonance Imaging*
Relaxation*

Figure

• 

  Fig. 1 Representative images obtained and calculated from a subject (71 year-old woman). a. Sagittal slices obtained using the three-dimensional multi-echo gradient-echo sequence. Seven echo times (TE) were from 2.28 ms to 25.72 ms in 3.91 ms steps. b. T2* relaxometry maps c. R2* relaxometry maps

• 

  Fig. 2 Representative regions-of-interest overlayed in T2* map in the same subject of Fig. 1. a. Fibroglandular tissue b. Fat

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