Introducing a Freely Accessible Internet Database for Identification of Cerebral Aneurysm Clips to Determine Magnetic Resonance Imaging Compatibility

Abstract

Knowledge of the magnetic properties of cerebral aneurysm clips in patients undergoing magnetic resonance imaging (MRI) is imperative. In daily practice, however, it is often impossible to derive this information from previous medical records. The aim of this study was to develop a freely accessible internet database to identify unknown cerebral aneurysm clips on the basis of conventional x-ray images of the cranium and to provide reliable information about their magnetic properties to allow safe MRI investigations in these patients. The 17 most commonly used clip series of the past 50 years were selected. The ferromagnetic properties of 47 example clips were examined by means of the Food and Drug Administration-approved "deflection angle test." An HTML-based database has been developed using standard x-ray images in two planes and photographs of the clips. Furthermore, details about alloy, ferromagnetic properties, MRI compatibility, year of construction, and other characteristics identifiable on x-rays were included. Seven aneurysm clips (of four clip models) were judged to be not MRI-compatible. The database named "ClipFinder" allows easy identification of cerebral aneurysm clips on standard cranial x-rays by comparing the films with the databank images supported by information on unique features of the clip design. On exemplary applications, ClipFinder provides a fast and easy-to-use database to identify unknown cerebral aneurysm clips via the internet and determine their MRI compatibility. The reliability of the identification system needs to be further evaluated in clinical practice before it can be recommended for widespread use.