Active guide wire and device decoupling with parallel transmit MRI


  • Image guided intravascular interventions are used to diagnose/treat a wide range of conditions. For cardiac applications they require devices to be inserted via a major vessel (e.g. in the groin) that are then steered through the patient’s vasculature to the heart. This may require guidewires and plastic/metal mesh catheters to contain or guide the device. These procedures typically occur under high frame rate x-ray imaging to allow the interventionist to visualise the devices and guide them to the required location in the anatomy.

The Problem

  • High frame rate x-ray imaging can include a significant radiation dose, which is particularly undesirable in children. It is also not easy to visualise the tissue using x-ray.
  • MRI guided intervention would have significant benefits including visualisation of tissue with much better contrast, and avoidance of radiation dose
  • However, guidewires and braided catheters are long conductive structures which are a hazard for MRI since the radio waves produced by the scanner can induce currents and cause localized tissue heating.
  • Wires and catheters do not show up clearly on MRI so guidance is also difficult.

The Solution

  • The MRI scanner can be modified to use an ‘active transmit coil’ consisting of multiple transmitters that can be controlled independently to cancel out induced currents, and hence make imaging safe
  • The active transmit coil can also preferentially induce currents on the wires/catheters, but at a very low power level. While safe, this also allows us to visualise the presence of the wire inside the body.
  •  This technology can solve both problems of safety and device visualisation


King’s are currently seeking commercial partners to help us develop this technology and bring the technology to market. A prospective development partner could take an option to a licence over the patent and associated know-how.


Figure 1: results from recent preclinical test. A guidewire was first imaged in visualisation mode (green area) showing no change in temperature. When the power is increased (red) we see a temperature change, but this is actively mitigated by switching to ‘null mode’ (cancelling the currents) where temperature increase drops to below 1°C

IP Status

A priority patent application was filed in the UK (having priority date 13th April 2016). An international patent application has been filed in the US (granted - US 10,753,991) and EU (pending).

Patent Information:
For Information, Contact:
Pushkar Wadke
King's College London
Shaihan Malik
Joseph Hajnal
Francesco Padormo
Felipe Godinez