Non-parametric intravoxel incoherent motion analysis of the thyroid gland
2017; Elsevier BV; Volume: 3; Issue: 1 Linguagem: Inglês
10.1016/j.heliyon.2017.e00239
ISSN2405-8440
AutoresAnton S. Becker, Moritz C. Wurnig, Tim Finkenstaedt, Andreas Boss,
Tópico(s)Advanced MRI Techniques and Applications
ResumoPurposeTo implement a protocol for intravoxel incoherent motion (IVIM) of the thyroid, to determine base parameters in healthy volunteers, and to provide preliminary experience on clinical applicability in one patient.Materials and methodsEight healthy volunteers underwent 3T MRI using a diffusion weighted echo-planar imaging sequence with 12 different b-values between 0–800 s/mm2. The IVIM parameters diffusion coefficient D, pseudo-diffusion coefficient D*, perfusion fraction Fp, and the optimal b-values thresholds were calculated for each thyroid lobe, muscle tissue and the cerebrospinal fluid (CSF) using a non-parametric multi-step algorithm and compared with a Student's t-test. A p-value <0.05 was considered significant.ResultsMean values for healthy thyroid tissue were: D 1.01 ± 0.13 × 10−3 mm2/s, D* 71.0 ± 52.5 × 10−3 mm2/s and Fp 17.1 ± 4.2%; for muscle: D 0.50 ± 0.21 × 10−3 mm2/s, D* 58.3 ± 99.2 × 10−3 mm2/s and Fp 26.5 ± 9.3%; and for CSF D 2.18 ± 0.93 × 10−3 mm2/s, D* 99.2 ± 41.2 × 10−3 mm2/s and Fp 74.6 ± 12.7%. The optimal b-value threshold separating diffusion and perfusion effects in thyroid ranged between 0–70 s/mm2. Healthy thyroid tissue showed similar Fp compared to muscle, both lower than CSF.ConclusionsThe proposed IVIM protocol provides surrogate markers on cellular diffusion restriction and perfusion; thereby providing a more comprehensive description of tissue properties compared to conventional DWI.
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