Dietmar Hentschel

Apparatus for the identification of nuclear magnetic spectra from spatially selectable regions of an examination subject

A method for identifying nuclear magnetic spectra from spatially selectable regions of an examination subject obtains an optimally unattenuated FID signal by the steps of cancelling the magnetization present due to the fundamental magnetic field in volume regions of the examination subject which are not to be evaluated, subjecting the examination subject to a non-selective RF read-out pulse which deflects at least the nuclear spins in the examination regions to be selected, and reading out the resulting FID signal following the non-selective RF read-out pulse. The selected examination region is determined by the transmission/reception characteristics of the coil which receives the FID signal minus the selectively saturated volume region.

Techniques for editing and visualizing CT-angiographic data

CT-Angiography acquires a volume of data defining vasculature in three dimensions. Prior to 3D visualization, bones have to be removed from the volume. We describe methods that reduce the workload for manual outlining of contours or remove bone structures in the abdomen, chest or head and neck region automatically. Volume rendering has been used to provide information not displayed with Maximum Intensity Projection or Surface Shaded Display. Tools have been developed to ease the setting of parameters for volume rendering of CT data.

Combining Two Imaging Modalities for Neuroradiological Diagnosis: 3D Representation of Cerebral Blood Vessels

Today the integration of information from different imaging modalities in medicine such as Computer Tomography or Magnetic Resonance Imaging (MRI) is left to the physician and gets little support from computers. In the case of neuroradiological diagnosis, information about cerebral blood vessels is available from 3D volume data from Magnetic Resonance Angiography (MRA) and from 2D images generated by Digital Subtraction Angiography (DSA). The DSA images have a higher resolution than MRA data, and therefore neuroradiologists are highly interested in a 3D reconstruction of cerebral blood vessels from different DSA projections. On the other hand, MRA contains important functional information, the velocity of blood flow. This paper describes work in progress to make available to the physician the full 3D information from both imaging modalities including an approach to 3D reconstruction from DSA im ages which makes use of the MRA data. The 3D DSA reconstruction also opens the way to an integration of information from DSA with completely different types of information, for example information on anatomical structure or soft tissue from MRI. An integral part of this work is a pilot system for clinical validation.