Abstract: A collimator, and in particular a method for making a collimator for use with a small high resolution single-photon emission computed tomographic (SPECT) imaging tool for small animal research. The collimator is sized, both functionally and structurally, particularly smaller than known collimators and appropriately scaled to achieve a highly sensitive collimator which facilitates desired reconstruction resolutions for small animals, as well as compliments other functional imaging modalities such as positron emission tomography (PET), functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and event-related potential (ERP), magneto-encephalography (MEG), and near-infrared optical imaging.

Abstract: A new and improved method and apparatus for determining cerebral oxygenation. In one basic aspect, a new processing methodology for oxygenation determination, in particular cerebral oxygenation, is provided based on the apprehension and discovery that time-based photon quantity determinations of the wavelength-specific light leaving the head of the patient may be significantly improved, and simplified, by determining the quantity of returning photons in at least one set of two different but closely spaced points in time following the instant of injection, and then taking the ratio of the determinations in each set, to thereby cancel and remove several important sources of error.