[Image postprocessing of aortic CTA and MRA]

Abstract

Multiplanar reformation (MPR) is the most relevant tool for patient selection and precise procedural planning and also for analyzing postinterventional complications. Curved MPR is used primarily for semiautomated or completely automated calculation of the centerline of the vascular lumen and to estimate the orthogonal vessel diameter and longitudinal extent. Reproducible and accurate measurement of complex pathologies and courses of vessels extends the range of diagnostic radiology. Contemporary scanner consoles allow automated processing of maximum intensity projections (MIP) and standard MPR and their storage in PACS. To improve patient selection, procedural planning, root-cause analysis postoperatively for assessment of treatment effects and to make better communication of findings to nonradiologists possible, volume rendering techniques (VRT) are a beneficial adjunct to source images. With current algorithms semiautomated segmentation is satisfactory for vessels and bones, but not for low-contrast structures (soft tissues), which still need to be segmented manually. In general, isotropic CT source data are preferable to MR images, which are often anisotropic. In many European countries image postprocessing is still not adequately reimbursed although the doctors making referrals often specifically and emphatically demand 3D visualization and measurements in daily practice.