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  • Crescenzi, R., Donahue, P. M., Braxton, V. G., Scott, A. O., Mahany, H. B., Lants, S. K., & Donahue, M. J. (2018). 3.0 T relaxation time measurements of human lymph nodes in adults with and without  lymphatic insufficiency: Implications for magnetic resonance lymphatic imaging. NMR in Biomedicine, 31(12), e4009. https://doi.org/10.1002/nbm.4009

    The purpose of this work was to quantify 3.0 T (i) T(1) and T(2) relaxation times of in vivo human lymph nodes (LNs) and (ii) LN relaxometry differences between healthy LNs and LNs from patients with lymphatic insufficiency secondary to breast cancer treatment-related lymphedema (BCRL). MR relaxometry was performed over bilateral axillary regions at 3.0 T in healthy female controls (105 LNs from 20 participants) and patients with BCRL (108 LNs from 20 participants). Quantitative T(1) maps were calculated using a multi-flip-angle (20, 40, 60°) method with B(1) correction (dual-T(R) method, T(R1) /T(R2)  = 30/130 ms), and T(2) maps using a multi-echo (T(E)  = 9-189 ms; 12 ms intervals) method. T(1) and T(2) were quantified in the LN cortex and hilum. A Mann-Whitney U-test was applied to compare LN relaxometry values between patients and controls (significance, two sided, p < 0.05). Linear regression was applied to evaluate how LN relaxometry varied with age, BMI, and clinical indicators of disease. LN substructure relaxation times (mean ± standard deviation) in healthy controls were T(1) cortex, 1435 ± 391 ms; T(1) hilum, 714 ± 123 ms; T(2) cortex, 102 ± 12 ms, and T(2) hilum, 119 ± 21 ms. T(1) of the LN cortex was significantly reduced in the contralateral axilla of BCRL patients compared with the axilla on the surgical side (p < 0.001) and compared with bilateral control values (p < 0.01). The LN cortex T(1) asymmetry discriminated cases from controls (p = 0.004) in a multiple linear regression, accounting for age and BMI. Human 3.0 T T(1) and T(2) relaxation times in axillary LNs were quantified for the first time in vivo. Measured values are relevant for optimizing acquisition parameters in anatomical lymphatic imaging sequences, and can serve as a reference for novel functional and molecular LN imaging methods that require quantitative knowledge of LN relaxation times.

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  • Donahue, P. M. C., Crescenzi, R., Scott, A. O., Braxton, V., Desai, A., Smith, S. A., Jordi, J., Meszoely, I. M., Grau, A. M., Kauffmann, R. M., Sweeting, R. S., Spotanski, K., Ridner, S. H., & Donahue, M. J. (2017). Bilateral Changes in Deep Tissue Environment After Manual Lymphatic Drainage in Patients with Breast Cancer Treatment-Related Lymphedema. Lymphatic Research and Biology, 15(1), 45–56. https://doi.org/10.1089/lrb.2016.0020

    Background: Breast cancer treatment-related lymphedema (BCRL) arises from a mechanical insufficiency following cancer therapies. Early BCRL detection and personalized intervention require an improved understanding of the physiological processes that initiate lymphatic impairment. Here, internal magnetic resonance imaging (MRI) measures of the tissue microenvironment were paired with clinical measures of tissue structure to test fundamental hypotheses regarding structural tissue and muscle changes after the commonly used therapeutic intervention of manual lymphatic drainage (MLD)., Methods and Results: Measurements to identify lymphatic dysfunction in healthy volunteers (n = 29) and patients with BCRL (n = 16) consisted of (1) limb volume, tissue dielectric constant, and bioelectrical impedance (i.e., non-MRI measures); (2) qualitative 3 Tesla diffusion-weighted, T1-weighted and T2-weighted MRI; and (3) quantitative multi-echo T2 MRI of the axilla. Measurements were repeated in patients immediately following MLD. Normative control and BCRL T2 values were quantified and a signed Wilcoxon Rank-Sum test was applied (significance: two-sided p < 0.05). Non-MRI measures yielded significant capacity for discriminating between arms with versus without clinical signs of BCRL, yet yielded no change in response to MLD. Alternatively, a significant increase in deep tissue T2 on the involved (pre T2 = 0.0371 ± 0.003 seconds; post T2 = 0.0389 ± 0.003; p = 0.029) and contralateral (pre T2 = 0.0365 ± 0.002; post T2 = 0.0395 ± 0.002; p < 0.01) arms was observed. Trends for larger T2 increases on the involved side after MLD in patients with stage 2 BCRL relative to earlier stages 0 and 1 BCRL were observed, consistent with tissue composition changes in later stages of BCRL manifesting as breakdown of fibrotic tissue after MLD in the involved arm. Contrast consistent with relocation of fluid to the contralateral quadrant was observed in all stages., Conclusion: Quantitative deep tissue T2 MRI values yielded significant changes following MLD treatment, whereas non-MRI measurements did not vary. These findings highlight that internal imaging measures of tissue composition may be useful for evaluating how current and emerging therapies impact tissue function.

    View for free on www.ncbi.nlm.nih.gov
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