Strange feelings and sensations in feet can be signs of peripheral neuropathy, but they usually occur in both feet. If its one sided it may be some other kind of nerve injury such as an impingement, like tarsal tunnel syndrom. It may be something altogether different so worthwhile pursuing, dont assume it has to be PN because your diabetic, it could be anything from brain tumor to pinched nerve in back, or a thousand other things. So follow it up.
Vascular studies are done with a small handheld doppler that actually measures arterial blood velocity. They can be used alone or in conjunction with pressure cuffs.
A doppler by itself can give good results but is very much dependent upon the operator and type of foot presented. A swollen ankle can make it almost impossible to get a meaningful result. Or if a vein is nearby it can give a false negative.
Dopplers should be used in conjunction with a normal blood pressure cuff to measure absolute blood pressure in both perpheral arteries at the ankle. An automated BP machine or stethoscope are no good for feet.
Ankles pressures should be compared with arm pressures and is called ankle brachial index. This will give an indication of whether the arteries are healthy or if arterial desease is present. Sometimes the ankles cannot be measured and so a big toe pressure index can be done instead. This test is more comfortable than ankle pressures and faster. It gives good results but not specific to either peripheral arteries. ABI and TPI are really only a quick test for clical assessment. If they show something wrong a more comprehensive duplex ultrasound should be done to confirm arterial disease, but these are expensive tests. ABI & TPI are good for annual checkups as they can detect onset of disease before symptoms appear. Since its possible for an artery to go from healthy to completely clogged in 2 years the importance of a good annual foot assessment becomes clear.
Your GP feeling for pulses is not good enough anymore as a severely diseased artery can still have a pulse.
