A catheter with a balloon anchor may be sized to fit through an inner needle and introduced into the patient through the needle. The inner needle may comprise an atraumatic needle with a side port and/or a blunt tip. The catheter may include a radiopaque coil disposed over the distal portion of the catheter body to assist with catheter placement when viewed with fluoroscopy and/or x-ray. The distal portion of the catheter can be very flexible. A balloon inflation tube may terminate proximal to a proximal end of the expandable balloon anchor such that the distal portion of catheter can be flexible. This termination of the inflation tube may also position the inflation tube away from the annulus and nerve roots, so as to avoid irritation of the annulus and rubbing of the nerve roots that may potentially obscure FAD test results.