Simple modification of a spin echo imaging pulse sequence generates useful spectroscopic information at 0.35 T. New images are produced that show water only, fat only, and the difference between water and fat intensity. Imaging speed, spatial resolution, and signal-to-noise ratio are comparable with ordinary imaging. The method provides new parameters for tissue characterization and improved contrast between some organs.

Magnetic resonance (MR) imaging methods with good spatial and contrast resolution are often too slow to follow the uptake of contrast agents with the desired temporal resolution. Imaging can be accelerated by skipping the acquisition of data normally taken with strong phase-encoding gradients, restricting acquisition to weak-gradient data only. If the usual procedure of substituting zeroes for the missing data is followed, blurring results. Substituting instead reference data taken before or well after contrast agent injection reduces this problem. Volunteer and patient images obtained by using such reference data show that imaging can be usefully accelerated severalfold. Cortical and medullary regions of interest and whole kidney regions were studied, and both gradient- and spin-echo images are shown. The method is believed to be compatible with other acceleration methods such as half-Fourier reconstruction and reading of more than one line of k space per excitation.

The research reported here develops an explanation for the often-noted absence of international war between democratic states. This explanation is derived from a theoretical rationale centered on universal democratic norms for reconciling competing values and interests. I argue that democratic states locked in disputes are better equipped than others with the means for diffusing conflict situations at an early stage before they have an opportunity to escalate to military violence. Not only is this explanatory logic consistent with the published findings on democracy and war, but it also entails the novel empirical proposition that disputes between democracies are more amenable than are other disputes to peaceful settlements, the hypothesis I examine here. Analyses of contemporary interstate disputes reveal that even when potentially confounding factors are controlled, democratic opponents are significantly more likely to reach peaceful settlements than other types of disputants.