Neuroimaging for Exploration of a 10-0 Needle Lost in the Cranium during Surgery

Abstract

We investigated the sensitivity and safety of postoperative neuroimaging in finding a 10-0 suture needle lost in the cranium during brain bypass surgery. A custom-made brainskull phantom with a 10-0 suture needle was used in this study.
The needle was barely detectable on digital X-ray photograph of the skull. Using computed tomography (CT), the intracranial location of the needle could be approximately determined; however, the location of the needle could not be precisely determined with either two-dimensional (2D) or 3D reconstruction imaging. Magnetic resonance imaging (MRI) depicted the needle as a metal artifact, and the intracranial location of the needle was more easily detected using MRI than by using CT. Diffusion weighted image (DWI) and T2^*WI were found to be more sensitive for detecting needles compared to T1WI and T2WI. In the gantry of the MRI scanner, although a needle hung by a thread held by the titanium forceps was pulled into the magnetic field, it could be retained with minimal resistance. The heat given off by the needle because of the magnetic field did not melt a chocolate tip beneath the needle.
The results of this study suggested that postoperative MRI is safe and can be used to find a lost needle in the cranium.