Radiation Safety + MRI
I am a Radiologist.
I have an interest in radiation safety.
There is NO limit to the dose my CT scanner gives a patient.
I authorise the use of radiation. I have had patients receive >50mSv for a diagnostic test.
The UK accepted rate for cancer induction is 1:20000 / mSv.
My patient has a death risk of 1:400 to look for a possible pathology they have a <1:4000 of having.
Dose is cumulative
Induction time lag is around 15-20 years.
I'll fry your granny - but not your kids.
Comparing targetted radiotherapy doses to tiny areas is not appropriate.
Yes we run XP / 7 for our underlying systems as the suppliers will not warrant any other environment.
The business end (custom hardware) works with its own internal systems (think CNC machine or 3d printer) screwing with the dose regulators is beyond the XP bit. When that goes down I have shut several scanners over the years - including writing one off! Mr Popular...
Dose is controlled by exposure factors set at the operators console (the XP bit) and the area covered and how many times.
The first acknowledged Fukishima related cancer is at a dose of 10-20mSv.
In the larger adult this dose is not uncommon on our current scanner(s) which are not particularly low dose.
New algorithms and technology is reducing delivered dose - but better tech is leading to multi phase exams that increase dose.
We have patients with accumulated doses of >200mSv, in an age range where this is an issue and a worse than 1:100 risk of death from their radiology scans.
Re MRI : it is a giant microwave. never mind there is no ionising radiation, it is perfectly possible to induce fits from neuronal stimulation from aggressive gradients or literally cook some one with RF energy.
We cannot air gap the provider need dial in access for fault finding and remote management when required.
We run NTPc on CT that connect to GMT-8 (ish) as that that is the worldwide system clock.
Radiology runs on a private subnet the firewall and bridging is managed.
Denial of service : highly likely
Manipulation of target devices : low - too varied, custom device v operators console manipulation
This is my day job at the pointy end. I spend some time on IT projects at work.
I remain a competent 6502 assembler programmer.