introduction:surgeosight is a dedicated intra-operative hand-held gamma camera designed and manufactured by our team to be used for lymphoscintigraphy. although conventional gamma cameras are widely used, they lack the capability of the sentinel lymph node (sln) imaging in the operation room. like conventional gamma cameras it is necessary to calibrate surgeosight for linearity distortion, ener...

Introduction:SURGEOSIGHT is a dedicated intra-operative hand-held gamma camera designed and manufactured by our team to be used for lymphoscintigraphy. Although conventional gamma cameras are widely used, they lack the capability of the sentinel lymph node (SLN) imaging in the operation room. Like conventional gamma cameras it is necessary to calibrate SURGEOSIGHT for linearity...

The use of super-wide angle and fish-eye lenses causes strong distortions in the resulting images. A methodology for the correction of distortions in these cases using only single images and linearity of imaged objects is presented in this work. Contrary to most former algorithms, the algorithm discussed here does not depend on information about the real world co-ordinates of matching points. M...

The front-end track-and-hold (T&H) circuit is one of the most critical components of an analog-todigital converter (ADC). Considering a pipelined ADC, it is known that the errors of each stage of the pipeline will be attenuated by the interstage amplifiers, however, the errors of the front-end T&H will be directly present in the output codes produced by the ADC. Because of this, the accuracy re...

Spatial encoding in MR techniques is achieved by sampling the signal as a function of time in the presence of a magnetic field gradient. The gradients are assumed to generate a linear magnetic field gradient, and typical image reconstruction relies upon this approximation. However, high-speed gradients in the current generation of MRI scanners often sacrifice linearity for improvements in speed...

In this article, a novel concept is introduced to improve the radio frequency (RF) linearity of partially-depleted (PD) silicon-on-insulator (SOI) MOSFET circuits. The transition due to the non-zero body resistance (RBody) in output conductance of PD SOI devices leads to linearity degradation. A relation for RBody is defined to eliminate the transition and a method to obtain transition-free c...

Longitudinal and multi-site clinical studies create the imperative to characterize and correct technological sources of variance that limit image reproducibility in high-resolution structural MRI studies, thus facilitating precise, quantitative, platform-independent, multi-site evaluation. In this work, we investigated the effects that imaging gradient non-linearity have on reproducibility of m...

The isocenter of the magnetic gradient fields inside a magnetic resonance imaging scanner is an important parameter in gradient non-linearity distortion correction methods for MR images. Currently there is no established method for estimating the gradient isocenter. All existing correction methods assume that the gradient isocenter coincides with the DICOM coordinate center, which is close but ...