Imagine you're being forced into a gravelike tube made of strong and hard metal, that you cannot escape. It doesn't matter whether you protest or not. Once there, you're subjected to uncomfortably bright light, and ominous, threatening, loud sounds fill what little air you have left for breathing.
A stock element of horror and thriller media: As part of a medical examination, the protagonist is put in a CAT, PET or MRI scanner. Cue the ominous loud sounds those machines make, and possibly some claustrophobia-induced nighmarish visions. Bonus points if the subject is already claustrophobic, paranoid or otherwise psychologically fragile. Extra bonus points if the tube turns out to malfunction in some hellish sort of way.
Note that this is about the claustrophobic imagery and feeling itself, not about what caused it or where it leads.
It's Truth in Television for people with actual claustrophobia. Even for people without claustrophobia, it can be deeply unnerving lying head-first inside a metal tube, surrounded by the loud noises of the machine running the scan.
If there are actual ghosts involved, this occurs as an illustration of Haunted Technology.
Has naught to do with Ghost in the Machine or Ghost in the Shell. Not necessarily connected to Digitized Hacker, though the potential is there. Nothing to do with standardized testing either, or cats for that matter.
- In Ghost in the Machine, while a serial killer is undergoing a CAT scan at the hospital, a surge of lightning courses through the building, and his soul is transformed into electrical energy. He then uses the electrical grid and computer networks to continue his killing spree.
- The Exorcist had a variation - as one transcript puts it, a huge machine, two pieces on either side of Regan's head and a piece above
- The mentally ill girl in Dark Floors (the Lordi monster film) is put into a CT machine and shortly thereafter begins to freak out. It's also where she starts when the monsters make the night start over again, something only she can remember.
- Played with in Venom (2018). After Eddie has bonded with the symbiote, Anne insists on getting him checked out. The sounds emitted from the MRI cause the alien physical pain because of its natural weakness to sonics, triggering a screaming freak out from it, and by extension Eddie too.
- Inverted in Scrubs where Elliot claims she uses a broken MRI machine as her "own little coccoon" when she's feeling stressed. She was surprisingly calm.
- JD meets Alex when he is forced to take care of her while she is stuck in an MRI machine for hours.
- In The X-Files episode "Theef", the poor doctor's poor wife is literally grilled in one of those, as the bad guy microwaves a Voodoo Doll of her.
- One of the challenges in Gaki no Tsukai ya Arahende involves a MRI scan. And has the contestants terrified.
- Kingdom Hospital plays with the Haunted Technology aspect in the episode "Butterfingers." Basically, Maine's most hated baseball player has just been admitted to Kingdom after a suicide attempt (gunshot to the head). After surgery, they want to put him in the MRI for additional testing, but Mrs. Druse protests that it'll send him into Swedenborgian space, from which there is no (known) exit. Fortunately, an incident in which a bullet gets stuck to the machine (It Makes Sense in Context) delays the procedure long enough for Dr. Hook to show up and cancel the MRI, because it would kill the patient... due to the its intense magnetic field interfering with the pacemaker he'd gotten some years earlier.
- A particularly dark Running Gag on House is the MRT machine causing all kinds of violent reactions on the patients placed inside. Not surprisingly, a few episodes have this happening because the patient has some kind of mental imbalance (most probably because of the disease affecting him) which triggers when placed within the machine and makes him have a panic attack.
- Subverted in Legion: David gets shoved into one of these, which is extremely uncomfortable for him because he's not only claustrophobic but highly schizophrenic. He fidgets...and twitches...and promptly bangs his head on the ceiling of the machine.
David: Oh, COME ON!
- Also happens to a guest character on Star Trek: Enterprise — though, in her defense, she'd never seen a CAT machine before.
- In the fifth level of Condemned 2: Bloodshot, Ethan crawls into a CT tube and promptly suffers a hallucination where the SCU headquarters and its agents are taken over by a black slime.
- For many people, claustrophobia is perfectly real, and a CT or MRI tube can easily trigger that. That's why they developed the Open MRI.
- Even for those without claustrophobia, medical machines that surround you with metal, bombard you with radiation, can make loud sounds that in other contexts could indicate structural failure, and are there to evaluate something that may be seriously sickening or killing you, inherently press several anxiety buttons.
- Subverted for others who find small spaces feel more protecting than open spaces.