scholarly journals Segmented 2D-selective RF excitations with weighted averaging and flip angle adaptation for MR spectroscopy of irregularly shaped voxel

2011 ◽  
Vol 66 (2) ◽  
pp. 333-340 ◽  
Author(s):  
Jürgen Finsterbusch ◽  
Martin G. Busch
Keyword(s):  
Mr Spectroscopy ◽  
Flip Angle ◽  
Weighted Averaging

Influence of editing pulse flip angle on J‐difference MR spectroscopy

2021 ◽  
Author(s):  
Sofie Tapper ◽  
Steve C. N. Hui ◽  
Muhammad G. Saleh ◽  
Helge J. Zöllner ◽  
Georg Oeltzschner ◽  
...  
Keyword(s):  
Mr Spectroscopy ◽  
Flip Angle

The Effect of Kalman-Weighted Averaging and Artifact Rejection on Residual Noise During Auditory Brainstem Response Testing

2019 ◽  
Vol 28 (1) ◽  
pp. 114-124
Author(s):  
Linda W. Norrix ◽  
Julie Thein ◽  
David Velenovsky
Keyword(s):  
Repeated Measures ◽  
Auditory Brainstem ◽  
Weighted Averaging ◽  
Auditory Brainstem Responses ◽  
Residual Noise ◽  
Electrophysiological Recordings ◽  
Artifact Rejection ◽  
Brainstem Response ◽  
Active Motor ◽  
Averaging Time

Purpose Low residual noise (RN) levels are critically important when obtaining electrophysiological recordings of threshold auditory brainstem responses. In this study, we examine the effectiveness and efficiency of Kalman-weighted averaging (KWA) implemented on the Vivosonic Integrity System and artifact rejection (AR) implemented on the Intelligent Hearing Systems SmartEP system for obtaining low RN levels. Method Sixteen adults participated. Electrophysiological measures were obtained using simultaneous recordings by the Vivosonic and Intelligent Hearing Systems for subjects in 2 relaxed conditions and 4 active motor conditions. Three averaging times were used for the relaxed states (1, 1.5, and 3 min) and for the active states (1.5, 3, and 6 min). Repeated-measures analyses of variance were used to examine RN levels as a function of noise reduction strategy (i.e., KWA, AR) and averaging time. Results Lower RN levels were obtained using KWA than AR in both the relaxed and active motor states. Thus, KWA was more effective than was AR under the conditions examined in this study. Using KWA, approximately 3 min of averaging was needed in the relaxed condition to obtain an average RN level of 0.025 μV. In contrast, in the active motor conditions, approximately 6 min of averaging was required using KWA. Mean RN levels of 0.025 μV were not attained using AR. Conclusions When patients are not physiologically quiet, low RN levels are more likely to be obtained and more efficiently obtained using KWA than AR. However, even when using KWA, in active motor states, 6 min of averaging or more may be required to obtain threshold responses. Averaging time needed and whether a low RN level can be attained will depend on the level of motor activity exhibited by the patient.

The findings of proton MR spectroscopy in chronic focal pancreatitis and pancreatic cancer

2001 ◽  
Vol 120 (5) ◽  
pp. A610-A610
Author(s):  
D LEE ◽  
J LEE ◽  
S JEONG ◽  
K KWON ◽  
W CHOI ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Mr Spectroscopy ◽  
Proton Mr Spectroscopy

Clinical MR Spectroscopy

2009 ◽  
Author(s):  
Peter B. Barker ◽  
Alberto Bizzi ◽  
Nicola De Stefano ◽  
Rao Gullapalli ◽  
Doris D. M. Lin
Keyword(s):  
Mr Spectroscopy

Proton MR Spectroscopy of the Hippocampus at 3 T

2004 ◽  
Vol 176 (03) ◽  
Author(s):  
F Träber ◽  
W Block ◽  
J Gieseke ◽  
O Guer ◽  
R Lamerichs ◽  
...  
Keyword(s):  
Mr Spectroscopy ◽  
Proton Mr Spectroscopy

Voxel MR Spectroscopy of Hippocampal Structures in Healthy Adults at 1.5 Tesla – How Stable are the Results?

2004 ◽  
Vol 35 (03) ◽  
Author(s):  
T Hammen ◽  
B Tomandl ◽  
B Neundörfer ◽  
H Stefan ◽  
H Single
Keyword(s):  
Mr Spectroscopy ◽  
Healthy Adults

Measurement of Lipid Content in Gallbladder Bile Using in- and opposed-phase MR Images and in vivo Proton MR Spectroscopy

2002 ◽  
Vol 46 (2) ◽  
pp. 127
Author(s):  
Sun Jin Hur ◽  
Seok Hwan Shin ◽  
Geum Nan Jee ◽  
Eun Joo Yun ◽  
Soon Gu Cho ◽  
...  
Keyword(s):  
Lipid Content ◽  
Mr Spectroscopy ◽  
Gallbladder Bile ◽  
Mr Images ◽  
Proton Mr Spectroscopy
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