Modeling and measurement of lead tip heating and resonant length for implanted, insulated wires.

Purpose: To study implant lead tip heating because of the RF power deposition by developing mathematical models and comparing them with measurements acquired at 1.5 T and 3 T, especially to predict resonant length.

Theory And Methods: A simple exponential model and an adapted transmission line model for the electric field transfer function were developed.

Evaluation of a compact 3 T MRI scanner for patients with implanted devices.

Access to high-quality MR exams is severely limited for patients with some implanted devices due to labeled MR safety conditions, but small-bore systems can overcome this limitation. For example, a compact 3 T MR scanner (C3T) with high-performance gradients can acquire exams of the head, extremities, and infants. Because of its reduced bore size and the patient being advanced only partially into the bore, the associated electromagnetic (EM) fields drop off rapidly caudal to the head, compared to whole-body systems.

The benefit of high-performance gradients on echo planar imaging for BOLD-based resting-state functional MRI.

Improved gradient performance in an MRI system reduces distortion in echo planar imaging (EPI), which has been a key imaging method for functional studies. A lightweight, low-cryogen compact 3T MRI scanner (C3T) is capable of achieving 80 mT m gradient amplitude with 700 T m s slew rate, in comparison with a conventional whole-body 3T MRI scanner (WB3T, 50 mT m with 200 T m s). We investigated benefits of the high-performance gradients in a high-spatial-resolution (1.