3D Ultrasound imaging - a useful non-invasive tool to detect AV fistulas in transplanted kidneys

Background. A precise, non-invasive, non-toxic, repeatable, convenient and inexpensive follow-up of renal transplants, especially following biopsies, is in the interest of nephrologists. Formerly, the rate of biopsies leading to AV fistulas had been underestimated. Imaging procedures suited to a det ailed judgement of these vascular malformations are to be assessed. Methods. Three-dimensional (3D) reconstruction techniques of ultrasound flo w-directed and non-flow-directed energy mode pictures were compared with a standard procedure, gadolinium-enhanced nuclear magnetic resonance imaging angiography (MRA) using the phase contrast technique. Results. Using B-mode and conventional duplex information, AV fistulas were localized in the upper Dole of the kidney transplant of the index patient. The 3D reconstruction provided information about the exact localization an d orientation of the fistula in relation to other vascular structures, and the flow along the fistula. The MRA provided localization and orientation i nformation, but less functional information. Flow-directed and non-flow-dir ected energy mode pictures could be reconstructed to provide 3D information about vascular malformations in transplanted kidneys. Conclusion. In transplanted kidneys, 3D-ultrasound angiography may be equal ly as effective as MRA in localizing and identifying AV malformations. Adva ntages of the ultrasound method are that it is cheaper, non-toxic, non-inva sive, more widely availability and that it even provides more functional in formation. Future prospective studies will be necessary to evaluate the two techniques further.