If you're claustrophobic don't read this. Or maybe you should because it might make you feel less alone in your phobia and less of a cowardly fool or it might even give you an excuse to have a sarcastic giggle at my expense. Be my guest.

Recently, I've been having some upper back pain which extends down into my right arm, causes some mobility problems and deadens sensation in my thumb and forefinger. At times it's quite painful but at others it's reduced to a mere unpleasant tingling. Maybe a pinched nerve or something. My doctor prescribed an x-ray and an MRI scan — perfectly normal procedures and essential for his informed diagnosis and future treatment.

I had the x-ray done the same day (thank you, French medical establishment). It was even a pleasant experience because the radiologist turned out to be a bright young doctor who sometimes brings his young son around to the club where I do my aeromodelling on weekends. He remembered me although I hadn't recognised him on sight, and we had a pleasant chat about scale models and how much his 5 year old enjoyed watching us fly them. The whole x-ray part of the procedure was fast, efficient, reimbursed by the "sécu" plus my "mutuelle" and not at all unpleasant. I walked away a few minutes later with the films and the radiologist's written report. That's France for you.

The MRI was a bit more complex because I had to book my slot on the machine at Cannes Hospital. My appointment was this sunny Saturday morning and I went into the bright pleasant waiting room (with view over conveniently nearby cemetery) at nine. So far so good.

I wasn't overly apprehensive. No one likes hospitals but machinery fascinates me and I was almost looking forward to my first sight of a Magnetic Resonance Imaging machine. How can anyone be brilliant enough to invent such a technical marvel?

Preparation was simple. I handed over my "carte vitale", filled in a questionnaire about whether I have a pacemaker and other things they needed to know, plus a final ominous question. "Are you claustrophobic?" Well I am a bit, but I didn't think it was all that bad (I fly in small jets without a problem) so I ticked midway between "oui" and "non". The girl gave a knowing smile. I was going to be the first of the day's problems and I think she knew it.

There were posters on the wall explaining what to expect — it's a noisy procedure so they make sure you know the racket is normal. I didn't even have to take my shirt or shoes off — just empty my pockets and remove my belt. Then into the MRI room and a first look at the machine. It's big and impressive, but that tube they slide you into is anything but. I started feeling a bit of apprehension.

A rather pretty young lady technician asked me to lie on my back on the sliding part of the machine and she put a button in my hand ("in case you want to stop") and a sort of frame over my upper body with a wide slit above my eyes. My head was almost in the tube. Apprehension started to mount well above normal. I knew it was for my own good but I didn't like this feeling. Not at all. I'd only been in the room for 30 seconds and I was sweating and felt like cardiac arrest wasn't far off. Sheer uncontrollable panic would be a pretty close description.

Now how reasonable is this? There is a technician in the room with me, my legs are sticking out of the machine, I have a panic button in one hand and I know the whole procedure is noisy, painless, isn't going to last more than 6 minutes (as long as I don't move) and will provide my doctor with important information.

I told the girl to stop. She smiled obligingly and told me I was the first today but that they have a few problem cases. She ushered in the next patient — a lady in a neck brace who looked like she was in some pain — and called the attending doctor. Nice guy. He took me aside and even tried — quite unnecessarily — to speak in English. Would I like to take a few minutes to compose myself before trying again? I would, thank you very much. I took deep breaths in time with the rhythmic racket I could hear from the room next door. The neck-brace lady came out smiling. It was my turn again.

Back on the table. Panic button in hand. Frame above my chest. Head in the tube. That was enough. I wanted out.

It's two hours later as I write this and I still haven't calmed down completely. My heart is still racing. I'd rather live in pain or even die in agony than get back in one of those machines. What do I mean "in"? I wasn't "in" the damned thing. Only my head and upper body were. But it would take a kilo of Valium to get me near that room again. There's no way.

I don't have other phobias to speak of although I'm not particularly fond of snakes or con men. But I can bring myself to touch them and even hit them with anything at hand, which is certainly a lot more risky than entering a piece of medical machinery in a controlled environment. Controlled environment? It was a bloody hospital for God's sake! How much safer can a place be? But phobias don't follow any logical pattern, do they?

As I write this I feel stupid, cowardly and disappointed with myself. I have a great doctor. A tolerant and humane man doing a difficult underpaid job with true compassion. How dare I refuse him the data he needs to treat my condition? But I'd rather live in pain and even paralysis than get near one of those machines again.

Ask me to climb into a flimsily built microlight aircraft and fly it myself in a raging Mistral wind (as I did in my younger days) and I'm your man. But don't put me into the tube of a perfectly safe device in a controlled medical environment. There's no way.

Let this be a written record. The day I go to that great Riviera in the sky, I don't want to be put in a box. I want a lethal injection to be sure I'm dead and then I want my blood emptied just to be extra sure and then I want a stake driven through my heart. Then cremate me. But no box, not even a temporary holding box. No box!

It appears I'm not alone in this and there is even a recognised condition called "MRI Claustrophobia". I Googled it afterwards and the stats seem to vary from 4% to 25% of problem cases like mine. But that's not going to give my doctor the information he needs to treat me, is it?