No abstract

Metallic cranial bone flap fixation clamps were tested for compatibility at 1.5-T magnetic resonance (MR) imaging with standardized techniques. There was no magnetic field attraction, heating was minor, and artifacts involved a relatively small signal void. These data indicate that bone flap fixation clamps will not present risks to patients undergoing MR imaging procedures with MR systems of 1.5 T or less.

The purpose of this study was to evaluate the MR safety of cardiovascular catheters and accessories. Intravascular cardiovascular catheters and accessories were tested for MR safety at 1.5 T using previously described techniques with respect to the evaluation of magnetic field attraction (deflection angle method), heating (temperature measured immediately before and after performing MRI), and artifacts (using a fast spoiled gradient-recalled acquisition in steady state [GRASS] pulse sequence). Two devices were attracted (RV pacing lead and Oximetrix 3 SO2 optical module) by the static magnetic field. Each of the other objects displayed no attraction. Heating was +0.2 degrees C for the sample cardiovascular catheter tested (Opticath). Artifacts varied from moderate to severe, depending on the amount and type of metal present in the device. Despite these ex vivo test results, further safety consideration should be given to the cardiovascular devices that have a conductive wire component (ie, certain types of the cardiovascular catheters) because of the potential for inducing current and excessive heating in these devices during MRI, especially using a high-field-strength MR system. The cardiovascular catheters evaluated in this study or those with a similar design are not recommended for use in patients undergoing MRI procedures.

To evaluate the compatibility of a commercially pure titanium aneurysm clip associated with magnetic resonance (MR) imaging at 1.5 T. Artifacts of the Spetzler titanium aneurysm clip were compared with those produced by six different nonferromagnetic aneurysm clips. With the titanium clip, no magnetic attraction was present, heating was minor, and the artifacts involved a small signal void. With the six other aneurysm clips, artifacts were larger. The presence of Spetzler titanium aneurysm clips is safe at MR imaging at 1.5 T or less.

The purpose of this study was to evaluate the MR compatibility of ceramic instruments. Nine different ceramic instruments were tested with respect to ferromagnetism, heating, and artifacts using previously described techniques. There was no magnetic field attraction, temperature increases were < or = 1 degree C, and artifacts involved a signal void similar to the size and shape of each instrument. The ceramic instruments were demonstrated to be compatible with MR imaging and acceptable for use during intraprocedural MR imaging.