3 research outputs found
Improving B1 homogeneity in abdominal imaging at 3 T with light and compact metasurface
Radiofrequency field inhomogeneity is a significant issue in imaging large
fields of view in high- and ultrahigh-field MRI. Passive shimming with coupled
coils or dielectric pads is the most common approach at 3 T. We introduce and
test light and compact metasurface, providing the same homogeneity improvement
in clinical abdominal imaging at 3 T as a conventional dielectric pad. The
metasurface comprising a periodic structure of copper strips and parallel-plate
capacitive elements printed on a flexible polyimide substrate supports
propagation of slow electromagnetic waves similar to a high-permittivity slab.
We compare the metasurface operating inside a transmit body birdcage coil to
the state-of-the-art pad by numerical simulations and in vivo study on healthy
volunteers. Numerical simulations with different body models show that the
local minimum of B1+ causing a dark void in the abdominal domain is removed by
the metasurface with comparable resulting homogeneity as for the pad without
noticeable SAR change. In vivo results confirm similar homogeneity improvement
and demonstrate the stability to body mass index. The light, flexible, and
cheap metasurface can replace a relatively heavy and expensive pad based on the
aqueous suspension of barium titanate in abdominal imaging at 3 T.Comment: 18 pages, 6 figures, 4 supplementary figure
The Largest Unethical Medical Experiment in Human History
This monograph describes the largest unethical medical experiment in human history: the implementation and operation of non-ionizing non-visible EMF radiation (hereafter called wireless radiation) infrastructure for communications, surveillance, weaponry, and other applications. It is unethical because it violates the key ethical medical experiment requirement for “informed consent” by the overwhelming majority of the participants.
The monograph provides background on unethical medical research/experimentation, and frames the implementation of wireless radiation within that context. The monograph then identifies a wide spectrum of adverse effects of wireless radiation as reported in the premier biomedical literature for over seven decades. Even though many of these reported adverse effects are extremely severe, the true extent of their severity has been grossly underestimated.
Most of the reported laboratory experiments that produced these effects are not reflective of the real-life environment in which wireless radiation operates. Many experiments do not include pulsing and modulation of the carrier signal, and most do not account for synergistic effects of other toxic stimuli acting in concert with the wireless radiation. These two additions greatly exacerbate the severity of the adverse effects from wireless radiation, and their neglect in current (and past) experimentation results in substantial under-estimation of the breadth and severity of adverse effects to be expected in a real-life situation. This lack of credible safety testing, combined with depriving the public of the opportunity to provide informed consent, contextualizes the wireless radiation infrastructure operation as an unethical medical experiment