The Best Diagnostic Tool for NASH

One of the questions I see asked all of the time is what kind of testing is the best to determine if someone has NASH. I’ve written about the challenge of diagnosis before, but there are a lot of scared individuals out there trying to get answers from their under-educated primary case physicians, and everyone wants to skip the preliminary steps and go straight to a definitive diagnosis. If only it were that easy!

MRE as a diagnostic tool

At a recent NASH conference I attended, there seemed to be a strong consensus that imaging tests were the best solution currently available. Recently, elastography has emerged as one of the most accurate non-invasive test available. Fibroscan (transient elastography) is the most common type available, but a newer breed of MRI machines that combine resonance imaging with elastography is setting the new gold standard.

These exams, known as MREs, were invented at the Mayo Clinic and are being deployed around the world. Research has shown MRE to be superior to TE at NASH diagnosis, including the identification of specific NASH stages.

It works by combining a traditional MRI with an elastography sensing machine. A small pad is placed on the abdomen above the liver which emits low-frequency sound vibrations. These vibrations are imaged using the MRI machine and processed by a computer which produces the resulting elastograph (a stiffness map). Sound will travel more quickly through harder tissue, which allows this to be a very accurate measure of fibrosis.

So just give everyone an mre?

The challenge is that not everyone can (or should) get a MRE. An expert speaker at the conference provided the illuminating figures: There are only 100 to 120 MRE machines currently in the USA, and about the same in the rest of the world.

There are ~ 1.8 billion people worldwide with NAFLD (based on ~25% global incidence). There are ~250 million people worldwide NASH (~3.5% global incidence). In the USA alone we have nearly 100 million NAFLD and 30 million NASH cases.

An average MRE exam takes 30 minutes. If we went to the extreme and tested every possible NASH case in the USA…it would take over 14 years. That’s running the 120 machines in the country 24 hours per day and only using them for liver exams. The average MRI cost is ~$3000 per scan as well, so we’d be looking at $90 billion dollars to test the entire US population.

So MRE may be the best overall (non-invasive) test, but we need to be discerning in how we select those that get it. It may be the case that it is very good for clinical research exams or for patients with suspected advanced stages, but not for the general population of NASH patients.

The best diagnostic tool: you

So if you have NASH, what tests should you be pushing your doctor for? The answer is a very frustrating “it depends”. You need to be familiar with all of the options that are out there, and seek the advice of a good hepatologist. If your blood tests are irregular, and you have other signs of NASH progression, push for MRE if possible.

The definitive test is still the biopsy, of course. So what do those numbers look like? From the figures given in the conference; ~50 thousand patients were biopsied for suspected NASH in 2016. Of those, 30k were diagnosed at stages f2/f3. A very small portion was f4 and the rest were f1 or non-conclucsive.

One key restraint on the use of biopsies (besides the enormous number of potential patients) is that doctors are hesitant to order them due to there currently being no medical treatment. As a result, most doctors will wait until later stages are diagnosed with non-invasive methods before ordering the procedure.

I have heard from many patients who were initially diagnosed with NAFLD or even NASH and told that it “wasn’t a big deal” and just to be more healthy. And then their doctors didn’t follow up until the next annual checkup, or even mention it at all for many years.

Until primary care physicians receive more education about the dangerous progression of NASH, the most effective diagnostic tool is YOU.

The best thing you can do is be your own advocate with your doctors and make sure you are doing everything possible to be healthy. Eat a balanced diet (cut the sugar!), restrict alcohol. and exercise. These are not as easy as taking a pill, but waiting around for a medical miracle is not the solution.