Wat veroorzaakt de geluiden die een MRI-scanner maakt?

Gezien je achtergrond en de dingen die je zelf aan haalt, zal Engels niet een heel groot probleem zijn ;-)
(daarbij heb ik nu even niet de tijd om het te vertalen)

Acoustic noise in most imaging environments arises from various sources. Continuous noise can originate from ancillary equipment located in the room that houses the imager. This equipment often includes a pump for liquid helium used to supercool the imager’s permanent magnet, a fan for supplying ventilation to the patient, and the air-handling equipment for the imager room. The highest-level noise, however, is intermittent and is produced whenever an image is acquired. To generate images, MRI uses both the static field of a permanent magnet and temporally varying magnetic field gradients to manipulate the nuclear spins of hydrogen nuclei (protons) in the body (e.g., Bushong, 1996; Cohen, 1998). Three sets of coils wound on a cylindrical fiberglass core are used to set up magnetic field gradients orthogonal and parallel to the long axis of the imager bore (e.g., Hedeen and Edelstein, 1997; see Fig. 1). When current is passed through these coils to set up the gradients, the resulting magnetic forces on the coils cause them to flex and thereby generate audible acoustic noise (e.g., Hurwitz et al., 1989; Schmitt et al., 1998). Flexure of the gradient coils can also produce acoustic noise secondarily. For example, vibration of the coils and the core on which they are wound can be conducted through the core supports to the rest of the imager’s structure, which responds by vibrating noisily. Where the connections between the core and its supports are not rigid, parts can rattle against each other, further adding to the noise (Hurwitz et al., 1989; Kelley, 1994). Although the exact noise may differ somewhat between imaging facilities, the generating mechanisms and characteristics may well be similar among commercial imagers. In this paper, acoustic noise produced directly or indirectly by the action of the gradient coils will be referred to as “gradient noise.”

Volledige artikel:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2270941/

Toegevoegd na 1 minuut:
Bottomline,
Veel bewegende onderdelen, stroom voor de variabele magneet, pompen die koelvloeistof door het apparaat heen pompen, etc.

Toegevoegd na 1 minuut:
Als je een vertaling wil, geef het even aan. Doe ik dat alsnog.