Setting off the airport sensors

The last three trips I made this year had me setting off the airport security sensors.
It happened once at the Budget Terminal, once returning home from Tokyo Narita and once at Phuket. The reason?

Gory, isn't it !!!
That's the platinum implants in my spine to correct the slipped disc problems I had last year.

Got the X-rays off my doctor today when I went for that 'see me in 6 weeks' consultation. And the prognosis? "Nothing seems wrong, continue with the medication, acupuncture and come back in 2 months."

The screws and pins will make the 2 vertebrates fuse in about 2 years time.
Medically, it's termed as L4 and L5. This is the most common place where slipped discs occur. It's there permanently and need not be removed. I hope.

And it's what's been tripping off the sensors each time I pass through the security panels at airports. I get stopped every time and each time when they do a manual scan on me, they always think it's my belt buckle that set it off. Of course, I'm not going to bother telling them my medical history, so long as I get passed.

Strangely, it had never happened at Changi Airport; not counting the Budget Terminal.
Hmmm, I wonder?