scholarly journals A water suppression model for wildfires

Keyword(s):  
2021 ◽  
Vol 11 (8) ◽  
pp. 3434
Author(s):  
Ming-Fang Lin ◽  
Lu-Han Lai ◽  
Wen-Tien Hsiao ◽  
Melissa Min-Szu Yao ◽  
Wing-P Chan

With advancements in aesthetic medicine, breast augmentation has become a popular plastic surgery worldwide, typically performed using either fine-needle injection or silicone implants. Both carry complication risks from rupture over time. In this study, we aimed to reduce misjudgments and increase diagnostic value by developing an MRI technique that can produce water- and silicone-specific images from MRI scans of phantoms (Natrelle® saline-filled breast implants) and human bodies. Pig oil, soybean oil, and normal saline were used to simulate human breast tissue, and two common types of breast implants, saline bags, and silicone bags, were selected as well, resulting in five materials scanned. Six pulse sequences were applied: T1W fast spin echo (FSE), T1W SPGR/60, T2W, T2W fat-saturation, STIR, and STIR water-saturation. Human body scans were additionally investigated using 3D SPGR fat-saturation dynamic contrast enhancement. Results show that the best way to enhance tissue contrast in images of silicone implants is to apply STIR combined with water suppression, and the best way to enhance saline bag implants is to apply T2W fat-saturation combined with fat suppression. Both offered very high sensitivity and specificity, rendering this method especially useful for distinguishing normal mammary glands from siliconoma.


2001 ◽  
Vol 152 (1) ◽  
pp. 168-178 ◽  
Author(s):  
Z. Starčuk ◽  
Z. Starčuk ◽  
V. Mlynárik ◽  
M. Roden ◽  
J. Horký ◽  
...  
Keyword(s):  

2010 ◽  
Vol 28 (5) ◽  
pp. 669-675 ◽  
Author(s):  
Grzegorz L. Chadzynski ◽  
Uwe Klose

1998 ◽  
Vol 11 (6) ◽  
pp. 266-272 ◽  
Author(s):  
M. Mescher ◽  
H. Merkle ◽  
J. Kirsch ◽  
M. Garwood ◽  
R. Gruetter

2021 ◽  
Vol 15 ◽  
Author(s):  
Gerard Eric Dwyer ◽  
Alexander R. Craven ◽  
Justyna Bereśniewicz ◽  
Katarzyna Kazimierczak ◽  
Lars Ersland ◽  
...  

The blood oxygen level dependent (BOLD) effect that provides the contrast in functional magnetic resonance imaging (fMRI) has been demonstrated to affect the linewidth of spectral peaks as measured with magnetic resonance spectroscopy (MRS) and through this, may be used as an indirect measure of cerebral blood flow related to neural activity. By acquiring MR-spectra interleaved with frames without water suppression, it may be possible to image the BOLD effect and associated metabolic changes simultaneously through changes in the linewidth of the unsuppressed water peak. The purpose of this study was to implement this approach with the MEGA-PRESS sequence, widely considered to be the standard sequence for quantitative measurement of GABA at field strengths of 3 T and lower, to observe how changes in both glutamate (measured as Glx) and GABA levels may relate to changes due to the BOLD effect. MR-spectra and fMRI were acquired from the occipital cortex (OCC) of 20 healthy participants whilst undergoing intrascanner visual stimulation in the form of a red and black radial checkerboard, alternating at 8 Hz, in 90 s blocks comprising 30 s of visual stimulation followed by 60 s of rest. Results show very strong agreement between the changes in the linewidth of the unsuppressed water signal and the canonical haemodynamic response function as well as a strong, negative, but not statistically significant, correlation with the Glx signal as measured from the OFF spectra in MEGA-PRESS pairs. Findings from this experiment suggest that the unsuppressed water signal provides a reliable measure of the BOLD effect and that correlations with associated changes in GABA and Glx levels may also be measured. However, discrepancies between metabolite levels as measured from the difference and OFF spectra raise questions regarding the reliability of the respective methods.


2004 ◽  
Vol 171 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Jin-Hong Chen ◽  
Elliot B. Sambol ◽  
Peter T. Kennealey ◽  
Rachael B. O’Connor ◽  
Penelope L. DeCarolis ◽  
...  
Keyword(s):  
1H Nmr ◽  

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