Affect of Endoscopic Clip on MR Imaging ; An Experimental Study on its Safety and its Imaging Artifact

The endoscopic clip is made from austenite of stainless steel which consist of Fe, Ni, and Cr. The austenite does not have magnetism its-self, however, slight magnetism is produced in the plastic workings during manufacturing of the clips. And there were no reports with respect to the affect of endoscopic clip on MRI. Therefore, the experimental studies on physical injury and imaging artifact of the endoscopic clip associated with MRI were carried out. The materials in this studies were 12 endoscopic clips (MD-850) which grasped a chunk of fresh beef, and a MRI equipment used was the Gyroscan, ACS-II (1.5T) . Scanning condition was spine-echo (T1-weighted image, T2-weighted image, proton density-weighted image) and field-echo similar to clinical usage. Total time of the scanning was one hour. All clips remained on the beef throughout the scanning, and there were no physical injuries around them. However, the imaging artifact of the endoscopic clip became bigger in such an order as, T1-weighted image, proton density-weighted image, T2-weighted image and field-echo. We conclude that MRI examination being carried out with the remaining endoscopic clips is a safe procedure.