Abstract: A combined imaging plate scanning and erasing system, comprising: (a) a housing; (b) an imaging plate cassette infeed assembly positioned within the housing, the maging plate cassette infeed assembly comprising: (i) a mechanism to pull an imaging plate cassette into the housing; (ii) a mechanism to open the imaging plate cassette; and (iii) a mechanism to remove an imaging plate from the cassette; (c) a scanner positioned within the housing; (d) a curved path erasing assembly positioned between the imaging plate infeed assembly and the scanner; and (e) an imaging plate transportation assembly to move the imaging plate back and forth in a path extending from the imaging plate cassette, past the erasing assembly and through a scan area adjacent to the scanner.

Abstract: A method of compensating for differences in detective gain between a plurality of different scanning heads in a multiple scanning head imaging plate scanner, comprising: (a) scanning each of the scanning heads across an imaging plate thereby determining the detected signal at successive locations across the imaging plate for each of the scanning heads; (b) calculating an inverse relationship to the detected signal at successive locations across the imaging plate for each of the scanning heads; (c) scanning each of the scanning heads across an imaging plate containing an image thereon, thereby determining an image value at the successive locations across the imaging plate for each of the scanning heads; and (d) applying the inverse relationship to the determined image values at the successive locations across the imaging plate for each of the scanning heads.

Abstract: A method of compensating for differences in detective gain between a plurality of different scanning heads in a multiple scanning head imaging plate scanner, comprising: (a) scanning each of the scanning heads across an imaging plate thereby determining the detected signal at successive locations across the imaging plate for each of the scanning heads; (b) calculating an inverse relationship to the detected signal at successive locations across the imaging plate for each of the scanning heads; (c) scanning each of the scanning heads across an imaging plate containing an image thereon, thereby determining an image value at the successive locations across the imaging plate for each of the scanning heads; and (d) applying the inverse relationship to the determined image values at the successive locations across the imaging plate for each of the scanning heads.

Abstract: A method for scanning an x-ray target in a reverse geometry x-ray imaging system with a charged particle beam is disclosed. An aspect of the invention is directed to scanning patterns for moving an electron beam across the target assembly to generate x-rays, in which a charged particle beam is moved across a plurality of sets of positions on a target assembly, wherein particular positions or sets of positions on the target assembly are rescanned a plurality of times during a single frame. The length of time between a first and a last illumination of the object during the frame is sufficiently small to prevent image blurring during image reconstruction.

Abstract: External field compensation is provided for MRI apparatus which is in a magnetically noisy environment such as that caused by nearby subway trains. By means of a magnetometer type sensor, the external field fluctuation is sensed and after being adjusted for the filtering effect of the magnet structure of the MRI device itself, the master oscillator of the MRI device is adjusted to compensate for the external field fluctuation. Alternatively the current of the magnet coil is adjusted.

Abstract: In an MRI method for optimizing flip angles for unequal delay times, a mathematical relationship is derived where RF flip angles can be determined to provide output signals which are constrained to be equal in amplitude and maximized in a sequence of MRI imaging.

Abstract: In an improved NMR imaging method, where three-nominally orthogonal gradient fields are generated, the quantization error of the phase encode gradient is reduced without the necessity of a digital to analog converter of higher bit capacity. This is accomplished in one embodiment by providing a second smaller gradient waveform which is relatively narrow compared to the primary gradient waveform, the ratio of the waveforms being proportional to the improved resolution. The second waveform can occur either before or after the 180.degree. excitation pulse used to produce a spin-echo signal. In another embodiment pulse width modulation is used to vary the area of the phase encode waveform in discrete increments.