System for renal movement elimination and renal diagnosis supported by vague knowledge

For the analysis of renal function, sequences of 90 magnet resonance images of the abdominal region showing both kidneys are taken in intervals of two seconds after a contrast medium was applied. Respiration of the patients during the acquisition of the images leads to organ movements throughout the series. These displacements are corrected by using an extended cepstral technique. To minimize registration errors caused by inhomogeneous movements of organs and tissues during respiration, the cepstrum-relevant part of the images is limited to small regions of interest around both kidneys. Even organ movements of sub-pixel range can be detected. After correction, the kidneys are the same position throughout the sequence. The regions of interest marked in one image are projected to all other images. To archive diagnostic results, dynamic contrast medium evaluations for different tissues of the kidneys are computed with signal-intensity-time graphs. Using a-priori knowledge about parameters of the SIT-graph for a whole kidney and about organ shape and structure, pixels of the kidney-segment are divided into the three classes renal cortex, medulla and pelvis. As a result, precise graphs can be computed for each tissue. The evaluation of the system is in progress, time save is more than one hour per patient.