Z-spectrum asymmetry : from 3T to 7T
نویسندگان
چکیده
Introduction: Magnetization Transfer and technically related effects such as CEST are important sources of contrast in MRI. Studying MT in vivo at 7T is challenging due to the increase in longitudinal relaxation time and SAR limits. To overcome this, we use pulsed saturation with EPI readout (MT-EPI) to measure MT at a range of offset frequencies and on the approach to steady-state in a reasonable imaging time. We have used these to compare the z-spectrum at 7 and 3T and investigate its asymmetry, as well as the sensitivity of MT at high field.
منابع مشابه
Increased cortical grey matter lesion detection in multiple sclerosis with 7 Tesla MRI : a postmortem verification study 2 . 3 7 T postmortem MRI and histopathology study
The relevance of cortical grey matter pathology in multiple sclerosis has become increasingly recognised over the past decade. Unfortunately, a large part of cortical lesions remain undetected on MRI using standard field strength. In vivo studies have shown improved detection by using higher magnetic field strengths up to 7 T. So far, a systematic histopathological verification of ultrahigh-fie...
متن کاملComparison of 3T and 7T susceptibility-weighted angiography of the substantia nigra in diagnosing Parkinson disease.
BACKGROUND AND PURPOSE Standard neuroimaging fails in defining the anatomy of the substantia nigra and has a marginal role in the diagnosis of Parkinson disease. Recently 7T MR target imaging of the substantia nigra has been useful in diagnosing Parkinson disease. We performed a comparative study to evaluate whether susceptibility-weighted angiography can diagnose Parkinson disease with a 3T sc...
متن کاملUltra-high field upper extremity peripheral nerve and non-contrast enhanced vascular imaging
OBJECTIVE The purpose of this study was to explore the efficacy of Ultra-high field [UHF] 7 Tesla [T] MRI as compared to 3T MRI in non-contrast enhanced [nCE] imaging of structural anatomy in the elbow, forearm, and hand [upper extremity]. MATERIALS AND METHOD A wide range of sequences including T1 weighted [T1] volumetric interpolate breath-hold exam [VIBE], T2 weighted [T2] double-echo stea...
متن کاملSolutions of Sample Problems for Second In-Class Exam
(b) Give a general real solution of the homogeneous equation Ly = 0. Solution. A general solution is y = c1e −2t cos(3t) + c2e −2t sin(3t) + c3 cos(7t) + c4 sin(7t) + c5t cos(7t) + c6t sin(7t) + c7e 5t + c8t e 5t + c9t e + c10e −3t + c11 + c12t . The reasoning is as follows: • the single conjugate pair −2± i3 yields e cos(3t) and e sin(3t); • the double conjugate pair ±i7 yields cos(7t) , sin(7...
متن کاملAssessing functional connectivity measures at 3T and 7T
Introduction: Functional connectivity, implied by inter-region correlation, has previously been reported in spontaneous resting state BOLD activity. Previous work has shown high correlation between BOLD fMRI signals from functionally related disparate brain regions e.g. 1 implying that brain activity in these regions is connected even in the absence of external stimuli. It is well known that as...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2008