[Volume determination with 3D ultrasound exemplified by aneurysms of the abdominal aorta]

Ultrasound is the first diagnostic method concerning initial and follow-up investigations of patients with abdominal aortic aneurysms. The indication is given by threatening rupture when disease is progressing. The aim of the presented study was to find out the applicability of 3D ultrasound and volumetry and to elaborate possible advantages of the new method in comparison with 2D sonography concerning the estimation of volumes. Preliminary investigations of defined volumes of waterfilled balloons confirmed the accuracy of +/- 4% (4 investigators) and the reliability of +/- 2% (10 investigations). With well-defined rating categories 3D scans were found to be quite good as well as excellent in 55% of the processed 3D data. Estimation of volume using 2D linked ellipsoid formula showed higher results in 92% of the cases than performing 3D volumetry. For a high accuracy of 3D volume estimation, contouring of 5 representative slices was quite sufficient. The presented results suggest a high accuracy and reliability of the new method. Further clinical investigations are necessary to find out the clinical relevance concerning the follow-up of patients with abdominal aortic aneurysms.