کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5406898 | 1393193 | 2009 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Generalized MAGSTE with bipolar diffusion-weighting gradient pulses
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Generalized MAGSTE with bipolar diffusion-weighting gradient pulses Generalized MAGSTE with bipolar diffusion-weighting gradient pulses](/preview/png/5406898.png)
چکیده انگلیسی
The generalized magic asymmetric gradient stimulated echo (generalized MAGSTE) sequence compensates background gradient cross-terms and can be adjusted to asymmetric timing boundary conditions which for instance are present in echo-planar MR imaging. However, its efficiency is not optimal because one of the two diffusion-weighting gradients applied in each interval usually must have a reduced amplitude to ensure the desired cross-term compensation. In this work, a modification of generalized MAGSTE is investigated where this gradient pulse is replaced by two gradient pulses with full amplitude but opposite polarities. It is shown that with these bipolar gradients (i) the sequence retains the cross-term compensation capability for an appropriate choice of the gradient pulse durations and (ii) the diffusion-weighting efficiency is improved, i.e. higher k and b values can be achieved without prolonging the echo time. These results are confirmed in MR imaging experiments on phantoms and in vivo in the human brain at 3Â T using spin-echo and echo-planar MR imaging. In the examples shown, the b value could be increased between about 30% and 200% when using the bipolar gradient pulses. Thus, bipolar gradients may help to improve the applicability of the generalized MAGSTE sequence.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetic Resonance - Volume 199, Issue 2, August 2009, Pages 214-224
Journal: Journal of Magnetic Resonance - Volume 199, Issue 2, August 2009, Pages 214-224
نویسندگان
Jürgen Finsterbusch,