PURPOSE To study the nonlinearity of myocardial signal intensity and gadolinium contrast concentration during first-pass perfusion MRI, and to compare quantitative perfusion estimates using nonlinear myocardial signal intensity correction. MATERIALS AND METHODS The nonlinearity of signal intensity and contrast concentration was simulated by magnetization modeling and evaluated in phantom meas...

Introduction: Functional MRI methods have been used to study sensorimotor processing in the brain and the Spinal cord. However, these techniques confront unwanted contributions to the measured signal from physiological fluctuations. For the spinal cord imaging, most of the challenges are consequences of cardiac and respiratory movement artifacts that are considered as signifi...

SUMMARY Background gradients induced by magnetic susceptibility variations near air-filled cavities in the brain cause signal-intensity loss in gradient-echo images and shorten T2* considerably. With a correction method in which the exponential decay is restored with section-profile-dependent correction factors, parts of the signal intensity can be recovered. While uncorrected T2* values drop b...

Differential base station sometimes is not capable of sending correction information for minutes, due to radio interference or loss of signals. To overcome the degradation caused by the loss of Differential Global Positioning System (DGPS) Pseudo-Range Correction (PRC), predictions of PRC is possible. In this paper, the Support Vector Machine (SVM) and Genetic Algorithms (GAs) will be incorpor...

a method for the simultaneous spectrophotometric determination of nickel, cobalt and copper based on theformation of their complexes with 2-(2-thiazolylazo)-p-cresol (tac) in micellar media of triton x-100 isproposed. the absorbance spectra were recorded in the range of 500 to 800 nm. the linear concentrationrange for nickel, cobalt and copper in solution calibration sets were 0.05–1.80, 0.10–6...

This paper presents a new correction technique for linear amplification with nonlinear components transmitters. During the transmit mode, the algorithm modulates and filters the baseband signal as a normal signal component separator, while during the correction mode, by use of a downconversion mixer, the gain and phase imbalance are measured and compensated by introducing a correction. This sys...

In functional connectivity analyses in BOLD (blood oxygenation level dependent) fMRI data, there is an ongoing debate on whether to correct global signals in fMRI time series data. Although the discussion has been ongoing in the fMRI community since the early days of fMRI data analyses, this subject has gained renewed attention in recent years due to the surging popularity of functional connect...

Introduction: In nuclear medicine imaging, detection of the scattered photons along with the primary photons is one of the major problems that can lead to a decrease in ddiagnostic accuracy. Therefore, use of a suitable scatter correction method can help to improve of the image quality and increase of diagnostic accuracy. The aim of this study is evaluation of five energy wind...