Non-parametric intravoxel incoherent motion analysis of the thyroid gland
نویسندگان
چکیده
PURPOSE To 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 METHODS Eight 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. RESULTS Mean 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. CONCLUSIONS The 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.
منابع مشابه
Intravoxel Incoherent Motion in Normal Pituitary Gland: Initial Study with Turbo Spin-Echo Diffusion-Weighted Imaging.
BACKGROUND AND PURPOSE DWI with conventional single-shot EPI of the pituitary gland is hampered by strong susceptibility artifacts. Our purpose was to evaluate the feasibility of intravoxel incoherent motion assessment by using DWI based on TSE of the normal anterior pituitary lobe. MATERIALS AND METHODS The intravoxel incoherent motion parameters, including the true diffusion coefficient (D)...
متن کاملIntravoxel Incoherent Motion-Magnetic Resonance Imaging as an Early Predictor of Treatment Response to Neoadjuvant Chemotherapy in Locoregionally Advanced Nasopharyngeal Carcinoma: Erratum
متن کامل
Perfusion measurement in brain gliomas with intravoxel incoherent motion MRI.
BACKGROUND AND PURPOSE Intravoxel incoherent motion MRI has been proposed as an alternative method to measure brain perfusion. Our aim was to evaluate the utility of intravoxel incoherent motion perfusion parameters (the perfusion fraction, the pseudodiffusion coefficient, and the flow-related parameter) to differentiate high- and low-grade brain gliomas. MATERIALS AND METHODS The intravoxel ...
متن کاملCerebral perfusion measurement in brain death with intravoxel incoherent motion imaging
Background: The assessment of brain death can be challenging in critically ill patients, and cerebral perfusion quantification might give information on the brain tissue viability. Intravoxel incoherent motion perfusion imaging is a magnetic resonance imaging technique, which extracts perfusion information from a diffusion-weighted sequence, and provides local, microvascular perfusion assessmen...
متن کاملIntravoxel Incoherent Motion Diffusion Weighted Magnetic Resonance Imaging for Differentiation Between Nasopharyngeal Carcinoma and Lymphoma at the Primary Site
OBJECTIVE The aim of the study was to investigate the utility of intravoxel incoherent motion (IVIM) diffusion-weighted magnetic resonance imaging (DWI) for differentiating nasopharyngeal carcinoma (NPC) from lymphoma. METHODS Intravoxel incoherent motion-based parameters including the apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudodiffusion coefficient (D*), perf...
متن کامل