Lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH) commonly affect older men. Fifty percent of men in their sixties and 80% of men in their nineties will be affected. Many of these men will seek care for their bothersome symptoms and decreased quality of life. There is a poor association between LUTS and objective measures such as post void residual, voided volumes, or maximal flow. Pressure flow studies are considered the gold standard for detecting bladder outlet obstruction. These studies tend to be cumbersome, expensive, and have exposure to ionizing radiation. There are several techniques which may offer noninvasive methods of detecting bladder outlet obstruction (BOO) in men.