Interventional procedures using X-Ray guidance have poor image/tissue contrast and deposit ionising radiation. Interventional MRI (iMRI) is an attractive alternative hindered by concerns about device safety, as the transmit field (B1+) can induce currents on interventional devices which can lead to dangerous focal energy deposition (1). Parallel Transmission (PTx) in conjunction with current sensors has enabled successful imaging whilst minimising induced radiofrequency (RF) current on guidewires, so reducing risk of tissue heating (2–4). A remaining problem in iMRI is visualisation of devices to allow guidance to the desired location. Many hardware and sequence design solutions have been proposed; here we present a strategy to visualise guidewires using PTx. Consider an N element PTx system with M current sensors placed on the exposed sections of a partially-inserted guidewire. The coupling (cm,n) of the nth transmitter to mth current sensor is found by measuring the induced currents whilst transmitting on each element sequentially. Performing an SVD on the MxN coupling matrix C generates N RF shims of unit-norm. The (N-M) shims with zero-valued singular values (referred to as dark modes, DMs) produce no wire current and can therefore be harnessed for safe imaging. The M remaining shims (referred to as coupling modes, CMs) produce wire currents and are typically discarded. It has been noted that wire currents produce a magnetic field whose magnitude is inversely proportional to the radial distance from the wire. Consequently, even small wire currents can produce significant B1+ adjacent to it. We propose the use of this mechanism to enable guidewire visualisation. Proof of principle experiments were performed on a 3T Philips Achieva with an 8-channel TEM body coil (5) and 6-channel torso rx-array. A guidewire (Terumo, Japan) was inserted into a meat phantom via embedded tubing filled with doped saline (0.7g/L NaCl, 0.02% Dotarem), shaped to mimic a 3D interventional guidewire trajectory. Currents on the exposed section of the guidewire (oriented parallel to B0) were monitored by two current sensors, whose signals were measured by the scanner spectrometer and power meters (Rohde&Schwarz NRP-Z11). The matrix C was determined using spectrometer measurements and six DMs were then calculated. B1+ maps of the modes were obtained using volumetric AFI (6,7) (transmitting in quadrature, FOV=370x92x120mm, res=33mm, FA=40°, BW=723Hz, TR1=25ms, TR2 = 125ms, TE=4.6ms) in conjunction with low flip angle SPGRs (8) of each mode (as AFI, except TR=10ms and FA=1°). Four sets of shims were used for imaging: a quadrature shim, shims comprised of the sum of the six DMs, the first CM, and the first CM reduced to 10% amplitude. Guidewire visualisation was tested using a multi-shot TSE (FOV = 300x150x51, res=0.75x1, dz=3mm, FA=90°, TSE factor=13, TR=4422ms, TE=52ms) with concurrent power monitoring.Figure 1 shows maximum intensity projections (MIPS) of B1+ maps of the CM and DM shims. The CM map exhibits large B1+ due to currents on the wire; this is not apparent for the DM map. Figure 2 shows example coronal TSE images. The guidewire is partially visible with quadrature shim (Fig.2A) due to uncontrolled coupling to both transmit and receive fields. Fig.2B shows an inherently safe imaging mode; the GW imparts an intensity modulation purely due to receive interaction. Fig.2C shows imaging with CM; signal is generated around the wire, but its large amplitude can cause heating and the resulting signals from the wire are too diffuse to facilitate visualisation. Fig.2D shows the image acquired with reduced amplitude CM – signal is restricted to immediately adjacent to the guidewire. Fig3 shows MIPs through the TSE volumes – accurate depiction of the guidewire location is only possible when using the reduced amplitude CM. Fig4 shows current sensor power readings for the first 25ms period of the TSE shot. CM produces the highest readings of 8W; reducing their amplitude to 10% reduces the power by a factor of 100 to the power level produced by quadrature.Successful guidewire visualisation has been demonstrated using the CM of a PTx array. All images exhibit receive enhancement due to the presence of a guidewire, however this is not sufficiently restrictive to allow visualisation. Operating with CM at low drive is vital for both safety and useful for visualisation. The proposed method is analogous to the reverse polarisation method (9), except with the RF field optimally designed to couple to the wire. Further work will explore tailoring the receive channel combination to further delineate the wire; in addition to interleaving transmission with DM shims (to visualise tissue) and CM (to visualise the wire) to enable real-time guidance.