The human spinal cord contains segregated sensory and motor pathways that have been difficult to quantify using conventional magnetic resonance imaging (MRI) techniques. Multiple sclerosis is characterized by both focal and spatially diffuse spinal cord lesions with heterogeneous pathologies that have limited attempts at linking MRI and behaviour. We used a novel magnetization-transfer-weighted...

R. D. Dortch, K. Li, A. A. Tamhane, E. B. Welch, D. F. Gochberg, J. C. Gore, and S. A. Smith Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United Sta...

Introduction Balanced steady state free precession (bSSFP) has been proposed recently for quantitative magnetization transfer (qMT) imaging [1]. Basically, bSSFP allows the determination of fundamental parameters of the two pool model [2], provided that T1 and B1 data are available. A critical point is the estimation of G0, which is the on-resonant singularity of the superlorentzian absorption ...

Introduction: Quantitative magnetization transfer imaging (QMTI) [1] allows in vivo mapping of the parameters of a two-pool model of MT in tissue [2] by the analysis of off-resonance saturation data, and is useful in the study of human white matter (WM). The two-pool model parameters are the restricted-to-free proton pool size ratio (F), the forward magnetization transfer rate (kf), and the rel...

Introduction Multiple sclerosis (MS) is an inflammatory disease of the central nervous system, whose neuroradiological hallmark are multifocal white matter (WM) lesions. Several pathological and MRI studies based on quantitative techniques have clearly demonstrated that diffuse abnormalities are present in the normal appearing WM (NAWM) and in lesions, and that they partially explain symptom se...

Ultrashort echo time imaging allows the short T(2) Achilles tendon to be directly visualized with MRI. Radiofrequency saturation 1 kHz or less off-resonance has been used previously to improve image contrast. In this study, magnetization transfer was investigated in the Achilles tendon of eight normal volunteers and one patient with psoriatic arthritis. 2D Ultrashort echo time images were acqui...

Introduction: For RF-spoiled gradient echo imaging (ie SPGR, FLASH, T1-FFE), the combination of spoiling gradients and quadratic phase cycling eliminates net transverse magnetization within a voxel [1-4] to enable pure T1 contrast. Generally, many RF excitations are required to attain steady state magnetization levels. Therefore, when unsaturated spins are flowing into the imaging volume, inflo...

Magnetization transfer ratio (MTR) has been often used for imaging myelination. Despite its high sensitivity, the specificity of MTR to myelination is not high because tissues with no myelin such as muscle can also show high MTR. In this study, we propose a new magnetization transfer (MT) indicator, MT asymmetry (MTA), as a new method of myelin imaging. The experiments were performed on rat bra...

Introduction: Liver biopsy, which serves as the clinical standard for the detection and surveillance of liver fibrosis and cirrhosis, is an invasive procedure that is prone to sampling error and interobserver variability. Magnetization-transfer contrast (MTC) imaging employs off-resonance radio-frequency pulses to selectively pre-saturate signal from macromolecule-bound protons via chemical exc...