Introduction Measuring the mean apparent diffusion coefficient (ADC) provides valuable contrast in studying disease processes such as stroke and tumours. ADC is usually measured by acquiring a reference image and 3 images with diffusion weighting (DW) applied in 3 orthogonal directions. ADC is then defined as the mean of the 3 diffusivity maps. This can be time consuming, and single-shot method...

The objective of this study was to evaluate the regional effects of bronchodilator administration in chronic obstructive pulmonary disease (COPD) using hyperpolarized helium-3 ((3)He) MRI apparent diffusion coefficient (ADC). Ten COPD ex-smokers provided written, informed consent and underwent diffusion-weighted, hyperpolarized (3)He MRI, spirometry, and plethysmography before and 25 ± 2 min af...

In this paper the testing of analog-to-digital converters (ADCs) by frequency-domain analysis in multi-tone mode is investigated. The theoretical expressions of some of the most important ADC dynamic parameters are derived. Also, the theoretical expression of the difference between the ADC effective number of bits (ENOB) obtained by testing in multi-tone mode and the ENOB obtained by testing in...

OBJECTIVE The aim of this study is to investigate the relation between renal indexes and functional MRI in a population of kidney transplant recipients who underwent MR with diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) of the transplanted graft. METHOD Study population included 40 patients with single kidney transplant. The patients were divided into 3 groups, on the ba...

Communications at mm-wave frequencies and above rely heavily on beamforming antenna arrays. Typically, hundreds, if not thousands, of independent channels are used to achieve high SNR for throughput increased capacity. Using a dedicated ADC per receiver is preferable but it’s practical very large arrays due unreasonable cost complexity. Frequency division multiplexing (FDM) well-known technique...

This research presents the review of Analog to Digital Convertor (ADC). For ADC there are mainly four different methods, Flash ADC, Pipelined ADC, Successive Approximation ADC, and Sigma Delta ADC. The Flash ADC is the Fast ADC. For Designing the ADC, the parameters important are Static and Dynamic. In static parameters Differential Non Linearity Error (DNLE), Integral Non Linearity Error (INLE...

This paper presents a cryogenic 8-bit 32 MS/s successive approximation register (SAR) analog-to-digital converter (ADC) which operates down to 4.2 K. work uses modified liquid helium temperature (LHT) SMIC 0.18 μm CMOS technology support the post-layout simulation. The proposed architecture adopts an offset-promoted dynamic comparator, waveform shaping circuit and true single-phase clock (TSPC)...

This paper presents the modeling and simulation of a 833.33 kS/s, 51.279μW successive approximation register(SAR) Analog to Digital Converter(ADC) using 0.18μm CMOS technology that uses internally generated signal for approximation for low power applications. The ADC is powered by single supply voltage of 1V. In our scheme, comparator output time and bit settling time of the Digital to Analog C...