Appearance of Pantopaque on MR images.

Pantopaque was shown to be both a radiographic and magnetic resonance (MR) contrast agent in two patients with suspected cord abnormalities who underwent MR examination following myelography. The Pantopaque appeared as a linear band of high signal intensity along the dependent portion of the spinal canal on MR images obtained with a repetition time of 500 msec and an echo time of 30 msec. MR images of two dogs--one injected with Pantopaque in the cervical subarachnoid space and the other with Amipaque--confirmed that the high signal arose from the Pantopaque. This high signal intensity is due to Pantopaque's short T1 relaxation time. Although Pantopaque will probably not be used as an MR contrast agent, it is important to recognize this property so that its high signal is not mistaken for fat or hemorrhage in the subarachnoid space on MR images.