Markus Prior

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Volunteers have undergone radio frequency hyperthermia in a magnetic resonance (MR) imaging system to investigate which of several possible MR parameters would be most convenient and sensitive to use to observe in vivo temperature changes. Measurements were made for T1, T2, and perfusion and diffusion variations, although the number of sequences needed at(More)
Models have been developed for the signal changes occurring in human peripheral muscle after thermal stress for some methods of measuring temperature in vivo. These include the dependency of T1 on temperature, observed by both direct, and magnetization transfer, experiments, and the temperature sensitivity of the diffusion coefficient and the chemical shift(More)
Preliminary experiences of the Sonotherm 6500 scanned focused ultrasound (SFUS) system in the hyperthermic treatment of bulky tumours in breast, superficial sites and within the pelvis in 22 patients are reported. Tumour volumes ranged from 235 to 603 cm3 (breast), 105 to 209 cm3 (superficial sites) and 24 to 905 cm3 (pelvis). Temperature distributions in(More)
Previous results for the measurement of T1 as a means of monitoring temperature have demonstrated a linear calibration with a coefficient of the order of 1.5%/degrees C. We have studied the changes in T1 further, and observe that changes in tissue perfusion are substantial contributors to the effects observed, and that the model of what is happening is(More)
A method of ablating the endometrium has been introduced into clinical practice that uses radiofrequency electromagnetic energy to heat the endometrium, using a probe inserted through the cervix. Preliminary studies suggest that over 80% of patients treated will develop either amenorrhea or a significant reduction in flow. The advantages of radiofrequency(More)
Some people are more politically interested than others, but political scientists do not know how stable these differences are and why they occur. This paper examines stability in political interest. Eleven different panel surveys taken in four different countries over 40 years are used to measure stability. Several studies include a much larger number of(More)
Despite dramatic increases in available political information through cable television and the Internet, political knowledge and turnout have not changed noticeably. To explain this seeming paradox, I argue that greater media choice makes it easier for people to find their preferred content. People who like news take advantage of abundant political(More)
A method of controlling the specific absorption rate (SAR) distribution in radiofrequency hyperthermia is proposed. The superposition of the current density associated with capacitively coupled electrodes and that associated with H-field coupled inductive aperture-type applicators modifies the actual current distribution in the heating material. Using a(More)
This article examines if the emergence of more partisan media has contributed to political polarization and led Americans to support more partisan policies and candidates. Congress and some newer media outlets have added more partisan messages to a continuing supply of mostly centrist news. Although political attitudes of most Americans have remained fairly(More)