Question: Is MRI harmful?
About the article "Magnetic resonance imaging", section "MRI versus CT".

Candidate passages:
The lack of harmful effects on the patient and the operator make MRI well-suited for "interventional radiology", where the images produced by an MRI scanner are used to guide minimally invasive procedures.
Of course, such procedures must be done without "any" ferromagnetic instruments.
A specialized growing subset of interventional MRI is that of intraoperative MRI in which the MRI is used in the surgical process.
Some specialized MRI systems have been developed that allow imaging concurrent with the surgical procedure.
More typical, however, is that the surgical procedure is temporarily interrupted so that MR images can be acquired to verify the success of the procedure or guide subsequent surgical work. 
The first neuroimaging technique ever is the so-called ‘human circulation balance’ invented by Angelo Mosso in the 1880s and able to non-invasively measure the redistribution of blood during emotional and intellectual activity.
Then, in the early 1900s, a technique called pneumoencephalography was set.
This process involved draining the cerebrospinal fluid from around the brain and replacing it with air, altering the relative density of the brain and its surroundings, to cause it to show up better on an x-ray, and it was considered to be incredibly unsafe for patients (Beaumont 8).
A form of magnetic resonance imaging (MRI) and computed tomography (CT) were developed in the 1970s and 1980s.
The new MRI and CT technologies were considerably less harmful and are explained in greater detail below.
Next came SPECT and PET scans, which allowed scientists to map brain function because, unlike MRI and CT, these scans could create more than just static images of the brain's structure.
Learning from MRI, PET and SPECT scanning, scientists were able to develop functional MRI (fMRI) with abilities that opened the door to direct observation of cognitive activities. 
 versus PET-CT.
Comparisons have been made between PET-MRI and PET-CT, some sources stating that PET-MRI is simply a X-ray radiation-free version of PET-CT (PET-MRI has as well Radiation from Biomarker).
In reality, there are differences beyond X-ray radiation dose. 
The Duret haemorrhage is demonstrated at CT or MRI.  
Interventional magnetic resonance imaging, also Interventional MRI or IMRI, is the use of magnetic resonance imaging (MRI) to do interventional radiology procedures.
Because of the lack of harmful effects on the patient and the operator, MR is well suited for "interventional radiology", where the images produced by an MRI scanner are used to guide a minimally-invasive procedure intraoperatively and/or interactively.
However, the non-magnetic environment required by the scanner and the strong magnetic radiofrequency and quasi-static fields generated by the scanner hardware require the use of specialized instruments.
For example, use of non-magnetic (e.g.
Titanium) surgical instruments and MR compatible patient surveillance accessories in addition to the costly MRI scanner increase the cost of IMRI.
Often required is the use of an "open bore" magnet, which permits the operating staff better access to patients during the operation.
Such open bore magnets are often lower field magnets, typically in the 0.2 tesla range, which decreases their sensitivity and temporal efficiency but also decreases the Radio Frequency power potentially absorbed by the patient during a protracted operation.
Higher field magnet systems are beginning to be deployed in intraoperative imaging suites, which can combine high-field MRI with a surgical suite and even CT in a series of interconnected rooms.
Specialty high-field interventional MR devices, such as the IMRIS system, can actually bring a high-field magnet to the patient within the operating theatre, permitting the use of standard surgical tools while the magnet is in an adjoining space.