Learn More
PURPOSE To evaluate the validity of different approaches to determine the signal-to-noise ratio (SNR) in MRI experiments with multi-element surface coils, parallel imaging, and different reconstruction filters. MATERIALS AND METHODS Four different approaches of SNR calculation were compared in phantom measurements and in vivo based on: 1) the(More)
The statistical properties of background noise such as its standard deviation and mean value are frequently used to estimate the original noise level of the acquired data. This requires the knowledge of the statistical intensity distribution of the background signal, that is, the probability density of the occurrence of a certain signal intensity. The(More)
PURPOSE We used a combined intravoxel incoherent motion-diffusion tensor imaging (IVIM-DTI) methodology to distinguish structural from flow effects on renal diffusion anisotropy. METHODS Eight volunteers were examined with IVIM-DTI at 3T with 20 diffusion directions and 10 b-values. Mean diffusivity (MD) and fractional anisotropy (FA) from DTI analysis(More)
Diffusion-weighted magnetic resonance imaging (DWI) is an imaging technique which is sensitive to random water movements in spatial scales far below those typically accessible by magnetic resonance imaging (MRI). This property makes DWI a powerful tool for diagnosis of diseases which involve alterations in water mobility, such as acute stroke. In bone(More)
PURPOSE To investigate technical feasibility, test-retest reproducibility, and the ability to differentiate healthy subjects from subjects with osteoarthritis (OA) with diffusion-tensor (DT) imaging parameters and T2 relaxation time. MATERIALS AND METHODS This study was approved by the institutional review board and was HIPAA compliant. All subjects(More)
BACKGROUND Most of the carotid plaque MR studies have been performed using black-blood protocols at 1.5 T without parallel imaging techniques. The purpose of this study was to evaluate a multi-sequence, black-blood MR protocol using parallel imaging and a dedicated 4-channel surface coil for vessel wall imaging of the carotid arteries at 3 T. MATERIALS(More)
The feasibility of a diffusion-weighted single-shot fast-spin-echo sequence for the diagnostic work-up of bone marrow diseases was assessed. Twenty healthy controls and 16 patients with various bone marrow pathologies of the spine (bone marrow edema, tumor and inflammation) were examined with a diffusion-weighted single-shot sequence based on a modified(More)
Accurate techniques for simulating the deformation of soft biological tissues are an increasingly valuable tool in many areas of biomechanical analysis and medical image computing. To model the complex morphology and response of articular cartilage, a hyperviscoelastic (dispersed) fiber-reinforced constitutive model is employed to complete two(More)
The purpose of this study was to evaluate the feasibility of a centric-reordered modified rapid acquisition with relaxation enhancement (mRARE) sequence for single-shot diffusion-weighted magnetic resonance imaging (DWI) of soft-tissue tumors in the musculoskeletal system. In the evaluation of this sequence, DWI was performed in a liquid phantom, in excised(More)
PURPOSE To assess the use of diffusion-tensor (DT) imaging of articular cartilage to detect and grade early cartilage damage in human specimens with early signs of cartilage damage. MATERIALS AND METHODS This study was approved by the institutional review board. Forty-three cartilage-on-bone samples drilled from 21 human patellae were examined with 17.6-T(More)