Effect of x-ray on film...chest x-ray

Garb · Apr 25, 2024

Yet another post about x-raying film...but it's different this time. It was a chest x-ray, not an airport scanner.

So I'm on the road and needed to go to the doctor and get a chest x-ray. Accidentally left my bag with all my film in it in a basket on the floor of the chest x-ray room. It'll be at least two weeks before I get a chance to develop any from this batch. Does anyone have any sense of how much damage a chest x-ray would be to film?

The x-ray technician left the room during the x-ray so presumably the whole room gets blasted, not just the area between the machine and the sensor behind my chest. So the film could have been exposed even if not in the direct path.

I'm just looking for something along the lines of "That film is toast" or "You won't know until you develop." If we know for a fact that the film is toast, I'll just stop using it altogether and buy new film while I'm still on the road, but if the answer is that the effect is unknown, I'll take a risk and continue using it. I have no sense of how strong medical chest x-ray is compared to airport scanners, but given that film generally survives a single pass through airport x-ray with minimal effects, I'm leaning towards continuing to use the film I had on me in that xray room.

OAPOli · Apr 25, 2024

The x-ray beam is collimated to the imaging area only and there is minimal scatter in the room. Chest X-rays have very little dose to begin with... 10 days outside gets you a similar exposure. Your film is 100% fine.

Andrew O'Neill · Apr 25, 2024

I had carry on film xrayed numerous times on a trip. I couldn't see any difference once processed. Now that said, medical xrays are considerably stronger than airport xrays.... so, I've heard. You will have to report back to us with the results (film results )

jeffreyg · Apr 25, 2024

X-rays travel in a straight line so your film should be ok

Garb · Apr 25, 2024

Thanks for the info, so I'll assume the film is still good to use.

Yes, x-ray and all light (visible or not) travels in a "straight" line (in quotes because gravitation lensing, but not relevant here). But the question remained on whether the xray was emitted omindirectionally or not, and also whether it bounces and scatters off anything in the room. Presumably yes it reflects because if it traveled through everything, it wouldn't really produce an image of my bones on the sensor. I do not believe the observation that light travels in a straight line is sufficient to establish that the film in the same room as the xray source was not fogged. I think the best indication it was not fogged was the earlier response, "x-ray beam is collimated to the imaging area only and there is minimal scatter in the room. Chest X-rays have very little dose to begin with... 10 days outside gets you a similar exposure. Your film is 100% fine."

MattKing · Apr 25, 2024

The reason that the technician leaves the room is that, there is a very small amount of scatter and reflection and, over time, someone who works with the equipment will otherwise be exposed to many such small doses, which can be cumulative in their affect.

koraks · Apr 26, 2024

Garb said:
But the question remained on whether the xray was emitted omindirectionally or not, and also whether it bounces and scatters off anything in the room.

There's a little scatter, but it'll be very minimal since it's not much to begin with, and most importantly it's usually mitigated by an anti-scatter plate that's held at the other side of the sample (patient). This is for safety purposes, but also to improve image quality since scatter would evidently degrade image quality.

Like @OAPOli said, your film will be just fine.

MattKing said:
The reason that the technician leaves the room is that, there is a very small amount of scatter and reflection and, over time, someone who works with the equipment will otherwise be exposed to many such small doses, which can be cumulative in their affect.

Moreover, safety culture plays a role. There are a few areas in society where we go above and beyond what you could argue to be reasonable levels of security. Commercial aviation comes to mind, but it's probably only second to anything related to "radiation".

railwayman2 · Apr 26, 2024

koraks said:
There's a little scatter, but it'll be very minimal since it's not much to begin with, and most importantly it's usually mitigated by an anti-scatter plate that's held at the other side of the sample (patient). This is for safety purposes, but also to improve image quality since scatter would evidently degrade image quality.

Like @OAPOli said, your film will be just fine.

Moreover, safety culture plays a role. There are a few areas in society where we go above and beyond what you could argue to be reasonable levels of security. Commercial aviation comes to mind, but it's probably only second to anything related to "radiation".

Agreed totally, your film will be fine, I was recently in hospital and both an anti-scatter plate was for chest x-rays and the technician left the the room every time. Remember the technician might be doing a few dozen x-rays 5-days a week, so
it's obvious to avoid any risk of accumulation of tiny doses over time. Even my dentist leaves the room when doing oral x-rays.

Fatih Ayoglu · Apr 26, 2024

The reason they escape from the room is they dont want to wear the heavy lead protectors, in the long run, it hurts their back (the technicians). For 10 years I have worked n the cath lab with constant Xray running and wear a dosimetry badge. AFAIK the dose was always under the limit

guangong · Apr 26, 2024

Not chest x-rays but during dental x-rays I usually place my bag with camera on a nearby cabinet without any damage. From my observations and experience, while radiology claims pinpoint direction of rays, there is damage to surrounding tissue due to flare in long term treatment. But I doubt if one shot chest x-ray would have any effect (unless wearing camera around neck).

wiltw · Apr 26, 2024

Ordinarily, medical x-ray exposure entails the use of a scintillator to expose the x-ray film to light. Only a small fraction of exposure of x-ray film comes from the direct effect on silver halide. An article

"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8724686/#:~:text=To reduce the radiation dose,the radiographic film [28].

"Although silver halide crystals can be directly exposed by the X-rays, a high dosage of X-rays with a risk of irradiation damage is required for qualified X-ray imaging. To reduce the radiation dose, a fluorescent intensifying screen made of scintillators was introduced for converting X-rays into ultraviolet to visible (UV-Vis) light to sensitize the radiographic film [28]. Figure 2(b) indicates that a radiographic film coupling with an intensifying screen substantially decreases the X-ray exposure as compared to exposing the radiographic film directly. Of which, 95% of the silver halide crystals are efficiently reduced via the visible light produced by intensifying screen, and the remaining are reduced by the direct interaction with X-rays."

So direct exposure of photographic film will be a small fraction of the response of x-ray film, even to the same direct beam. Since Garb's film was not in direct beam path, and the amout of scatter radiation is small, its response to x-ray is neglibble...after all, the film manufacturing companies assured us decades ago about the ability to pass photographic film multiple times to direct beam of Security x-ray scanners without any visible harm.

guangong · Apr 26, 2024

Nowadays, x-rays use digital capture. I haven't seen film used by my veterinarian, dentist, or physicians for a long time.

wiltw · Apr 26, 2024

guangong said:
Nowadays, x-rays use digital capture. I haven't seen film used by my veterinarian, dentist, or physicians for a long time.

Digital X-rays typically require less radiation exposure than traditional X-ray films, making them an even safer option for patients and photographic film.
Mammography was one of the last medical imaging to convert from film to digital imaging, a bit over 20 years ago, due to its need for finer detail than other forms of medical x-ray.

MattKing · Apr 26, 2024

My otherwise fully modern dentist still uses film x-rays. His experienced staff sometimes have to help the younger visiting hygienists who provide extra services when they haven't had much experience with the film based x-ray equipment since they finished their training.

grain elevator · Apr 26, 2024

Dental x-ray is still very commonly done on film here (Germany). I assume because fitting the digital stuff in a mouth is more challenging than just a piece of film.

wiltw · Apr 27, 2024

grain elevator said:
Dental x-ray is still very commonly done on film here (Germany). I assume because fitting the digital stuff in a mouth is more challenging than just a piece of film.

From the patient perspective, I find the digital receptor easier than opening every time to fit multiple pieces of film. The instant image also is nicer to instantly know if a retake is immediately needed, and nicer than waiting for film to process (and maybe require opening your mouth again for a re-take film to be placed)

alanrockwood · Apr 27, 2024

Speaking of dental x-rays, I get my dental work done at a dental school. I asked my student dentist if they are trained to use film, and at this school they do get training for film-based x-rays, though in treating patients they normally use digital sensors.

guangong · Apr 27, 2024

If there is any difference in size of the piece that goes into mouth for digital compared to film, I haven’t noticed it. The advantage of digital is instantaneous reading of results.

BrianShaw · Apr 27, 2024

grain elevator said:
Dental x-ray is still very commonly done on film here (Germany). I assume because fitting the digital stuff in a mouth is more challenging than just a piece of film.

At my dental practice, the digital "stuff" is a bit thicker than film but the process is the same... no more challenging or annoying. They put a plastic sleeve, somewhat like a condom, over the digi-sensor. I was never quite certain how those film holders were sanitized between patients.

Effect of x-ray on film...chest x-ray

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