>>The only way to accurately diagnose it is through imaging such as a CT or MRI scan.

As I remember, the 'gold standard' for this is a DEXA scan - a kind of low-dosage X-ray scan usually used to determine bone density - but also used for body composition.

There are also 'full body composition" scales that use impedance. A few of those (notably the Tanita FDA-approved ones) get pretty close to DEXA. I've seen residential models for $300-ish. There are also cheap composition scales that almost certainly don't match what DEXA can do - but they let you see from one day to the next what's going on. I have one of those, but would hesitate to recommend it (hey, it was under $20 and I needed a scale)...

That said, and with the usual caution that we all differ, I've found distance swimming to be nearly magical in removing visceral fat.