Has the culprit been found (hypertension)?

I wrote a week ago about the enzyme/hormone renin and the blood test that I had done, whose result I did not understand. A few days ago, I was notified about another result, presumably from the same blood sample, this time for aldosterone; again, the units defeated me and so I was unable to figure out what my aldosterone to renin ratio is.

This morning, my specialist called me on my cell phone (that's personal service for you) and explained that my renin level is exceedingly low (that's why it appeared as "less than 1.96") and that the aldosterone level is high. This suggests where the cause of my hypertension lays. The next step is to perform a 24-hour urinary excretion of aldosterone test: the patient eats a high-salt diet for a few days followed by urine collections over a 24-hour period. Instead of changing my diet, I will be prescribed special salt tablets in order to cause 'sodium load' and then I collect my urine.

The specialist will be able to make an informed diagnosis on the basis of this test. 

I wonder whether this means that I can cancel the special ultrasound test that I have to do at the end of May.