Radial spoiled gradient T1 weighted imaging of the internal auditory canal: Is Scarpa’s ganglion now an expected finding and source of fundal enhancement?

2022 ◽  
pp. 197140092110674
Author(s):  
Kamran Munawar ◽  
Eytan Raz ◽  
Seena Dehkharghani ◽  
Girish M Fatterpekar ◽  
Tobias K Block ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Internal Auditory Canal ◽  
Cotton Wool ◽  
Gradient Echo ◽  
Anatomical Variants ◽  
Tissue Contrast ◽  
Scarpa's Ganglion ◽  
Stack Of Stars

StarVIBE is a 3D gradient-echo sequence with a radial, stack-of-stars acquisition having spatial resolution and tissue contrast. With newer sequences, it is important to be familiar with sequence tissue contrasts and appearance of anatomical variants. We evaluated 450 patients utilizing this sequence; 35 patients demonstrated fluffy “cotton wool” enhancement at the internal auditory canal fundus without clear pathology. We favor this represents anatomic neurovascular enhancement that StarVIBE is sensitive to and is a touch-me-not finding.

scholarly journals High spatial resolution whole‐neck MR angiography using thin‐slab stack‐of‐stars quiescent interval slice‐selective acquisition

2020 ◽  
Vol 84 (6) ◽  
pp. 3316-3324
Author(s):  
Ioannis Koktzoglou ◽  
Rong Huang ◽  
Archie L. Ong ◽  
Pascale J. Aouad ◽  
Matthew T. Walker ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Mr Angiography ◽  
High Spatial Resolution ◽  
Thin Slab ◽  
Stack Of Stars

Towards Routine Clinical Use of Radial Stack-of-Stars 3D Gradient-Echo Sequences for Reducing Motion Sensitivity

2014 ◽  
Vol 18 (2) ◽  
pp. 87 ◽  
Author(s):  
Kai Tobias Block ◽  
Hersh Chandarana ◽  
Sarah Milla ◽  
Mary Bruno ◽  
Tom Mulholland ◽  
...  
Keyword(s):  
Clinical Use ◽  
Gradient Echo ◽  
Motion Sensitivity ◽  
Stack Of Stars

scholarly journals MR imaging of iliofemoral peripheral vascular calcifications using proton density-weighted, in-phase three-dimensional stack-of-stars gradient echo

2016 ◽  
Vol 77 (6) ◽  
pp. 2146-2152 ◽  
Author(s):  
Marcos P. Ferreira Botelho ◽  
Ioannis Koktzoglou ◽  
Jeremy D. Collins ◽  
Shivraman Giri ◽  
James C. Carr ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Three Dimensional ◽  
Proton Density ◽  
Peripheral Vascular ◽  
Gradient Echo ◽  
Vascular Calcifications ◽  
Stack Of Stars

k-Space filtering in 2D gradient-echo breath-hold hyperpolarized3He MRI: Spatial resolution and signal-to-noise ratio considerations

2002 ◽  
Vol 47 (4) ◽  
pp. 687-695 ◽  
Author(s):  
Jim M. Wild ◽  
Martyn N.J. Paley ◽  
Magalie Viallon ◽  
Wolfgang G. Schreiber ◽  
Edwin J.R. van Beek ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Signal To Noise Ratio ◽  
Breath Hold ◽  
Gradient Echo ◽  
Signal To Noise ◽  
Noise Ratio

High spatial resolution BOLD fMRI using simultaneous multislice excitation with echo-shifting gradient echo at 7 Tesla

2020 ◽  
Vol 66 ◽  
pp. 86-92 ◽  
Author(s):  
Shi Su ◽  
Na Lu ◽  
Lin Jia ◽  
Xiaojing Long ◽  
Chunxiang Jiang ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Gradient Echo ◽  
Bold Fmri ◽  
Simultaneous Multislice

scholarly journals A more accurate account of the effect of k-space sampling and signal decay on the effective spatial resolution in functional MRI

2016 ◽  
Author(s):  
Denis Chaimow ◽  
Amir Shmuel
Keyword(s):  
High Resolution ◽  
Functional Mri ◽  
Spatial Resolution ◽  
Spin Echo ◽  
7 Tesla ◽  
Gradient Echo ◽  
Magnitude Image ◽  
Signal Decay ◽  
The Absolute ◽  
High Pass

AbstractThe effects of k-space sampling and signal decay on the effective spatial resolution of MRI and functional MRI (fMRI) are commonly assessed by means of the magnitude point-spread function (PSF), defined as the absolute values (magnitudes) of the complex MR imaging PSF. It is commonly assumed that this magnitude PSF signifies blurring, which can be quantified by its full-width at half-maximum (FWHM). Here we show that the magnitude PSF fails to accurately represent the true effects of k-space sampling and signal decay.Firstly, a substantial part of the width of the magnitude PSF is due to MRI sampling per se. This part is independent of any signal decay and its effect depends on the spatial frequency composition of the imaged object. Therefore, it cannot always be expected to introduce blurring. Secondly, MRI reconstruction is typically followed by taking the absolute values (magnitude image) of the reconstructed complex image. This introduces a non-linear stage into the process of image formation. The complex imaging PSF does not fully describe this process, since it does not reflect the stage of taking the magnitude image. Its corresponding magnitude PSF fails to correctly describe this process, since convolving the original pattern with the magnitude PSF is different from the true process of taking the absolute following a convolution with the complex imaging PSF. Lastly, signal decay can have not only a blurring, but also a high-pass filtering effect. This cannot be reflected by the strictly positive width of the magnitude PSF.As an alternative, we propose to first approximate the MRI process linearly. We then model the linear approximation by decomposing it into a signal decay-independent MR sampling part and an approximation of the signal decay effect. We approximate the latter as a convolution with a Gaussian PSF or, if the effect is that of high-pass filtering, as reversing the effect of a convolution with a Gaussian PSF. We show that for typical high-resolution fMRI at 7 Tesla, signal decay in Spin-Echo has a moderate blurring effect (FWHM = 0.89 voxels, corresponds to 0.44 mm for 0.5 mm wide voxels). In contrast, Gradient-Echo acts as a moderate high-pass filter that can be interpreted as reversing a Gaussian blurring with FWHM = 0.59 voxels (0.30 mm for 0.5 mm wide voxels). Our improved approximations and findings hold not only for Gradient-Echo and Spin-Echo fMRI but also for GRASE and VASO fMRI. Our findings support the correct planning, interpretation, and modeling of high-resolution fMRI.

scholarly journals Quantifying the spatial resolution of the gradient echo and spin echo BOLD response at 3 Tesla

2005 ◽  
Vol 54 (6) ◽  
pp. 1465-1472 ◽  
Author(s):  
Laura M. Parkes ◽  
Jens V. Schwarzbach ◽  
Annemieke A. Bouts ◽  
Roel h R. Deckers ◽  
Pim Pullens ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Spin Echo ◽  
3 Tesla ◽  
Bold Response ◽  
Gradient Echo
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