I wonder whether the age of an MRI scanner (or how much it has been used) impact the quality of the scans. I.e., does the quality of the scans deteriorate as an MRI scanner gets older or more used?
This is more of a partial answer than a full answer.
First, it would be useful to understand the typical amount of time an MRI scanner is in service. A report from the European Society of Radiology suggests the typical MRI scanner has a useful lifetime of 8-12 years based on usage (2014. PMCI 4195838).
Some potentially useful data to address this question comes from a 2019 study of prostate MRI quality performed by Burn and colleagues (PMID 31296337). They found the following effect of scanner age:
Effect of scanner age
The influence of scanner age on image quality was assessed by comparing the two groups: MRI performed on scanners <7 years old (54 patients) and MRIs performed on scanners ≥7 years old (40 patients) and dichotomising image quality into diagnostic (image quality score ≥3) and non-diagnostic (score ≤2). For T2W, 80% were diagnostic in the newer scanner group, compared to 53% in the older scanner group (odds ratio 3.5, range 1.4–8.8, p=0.006). For DWI for the newer scanner group, 81% were diagnostic and in the older scanner group, 80% were diagnostic (odds ratio=1.2, range 0.3–5.9, p=0.8). The relationship between scanner age for each site and mean T2W overall quality score is shown in Fig 6, demonstrating an inverse correlation.
This seems to suggest higher quality images from younger scanners, at least for particular pulse sequences.
However, it is important to recognize that younger scanners are by definition newer models, and thus may have new and improved imaging algorithms. Indeed Burns and colleagues note this:
This clearly brings into focus the quality of the technique, particularly outside large academic centres and without access to latest-generation high-quality MRI systems and with limited scanner time.
So it is likely that at least some of this effect is based on the generation of the scanner, but it is still possible that there is some degradation of image quality over time.
Unfortunately, the authors do not discuss further. A paper by Giganti and colleagues mention the study but unfortunately do not provide additional insight (2022. PMID 34233502)
Another important aspect that should be taken into account is scanner age. Although this requires more investigation, Burn and colleagues have shown a significant difference in the quality of prostate MRI at a 7-year cut-off for scanner age and this is something that will need to be explicitly addressed in the next iteration of the PI-RADS recommendation.
To directly answer your question, we would need to assess image quality of scans taken from the same scanner over many years. However, I was unable to find any such study.