qMRI resources

The Perfect MR Machine

http://qmri.org/resources/perfect-machine

The Perfect qMR machine: measurement variance much less than biological variance

Paul S Tofts, Brighton and Sussex Medical School, University of Sussex BN1 9PX, UK


1. Summary

Implementing quantitative MR (qMR) methodology can be a time-consuming task, sometimes seemingly without an end. The concept of the Perfect qMR Machine offers the possibility that the implementation is complete and that no further improvements are needed. This is achieved by making the measurement repeatability variance much less than the biological variance. Thus the proposal is:

A Perfect Quantitative MR machine is one that, in making a measurement, contributes no significant extra variation to that which already exists from biological variation.

A medal system (platinum, gold, silver and bronze) recognises different sources of biological variance, depending on the type of measurement being carried out (whether a serial study or a group comparison, and whether on a single machine or multi-centre). A perfect machine can in principle be demonstrated for each quantitative measure (T1, ADC etc).


 link to publisher:

https://www.physicamedica.com/article/S1120-1797(22)02074-9/pdf

https://doi.org/10.1016/j.ejmp.2022.10.013

Author's preprint here

-------------------------------------------------------------------------------------------------------------------------------------
Here is a quote on the aviator and his perfect machine

Antoine de Saint ExupĂ©ry's Wind, Sand and Stars   1939


Meanwhile, startling as it is that all visible evidence of invention should have been refined out of this instrument and that there should be delivered to us an object as natural as a pebble polished by the waves, it is equally wonderful that he who uses this instrument should be able to forget that it is a machine. There was a time when a flyer sat at the center of a complicated works. Flight set us factory problems. The indicators that oscillated on the instrument panel warned us of a thousand dangers. But in the machine of today we forget that motors are whirring: the motor, finally, has come to fulfill its function, which is to whirr as a heart beats - and we give no thought to the beating of our heart. Thus, precisely because it is perfect the machine dissembles its own existence instead of forcing itself upon our notice. And thus, also, the realities of nature resume their pride of place. It is not with metal that the pilot is in contact, Contrary to the vulgar illusion, it is thanks to the metal, and by virtue of it, that the pilot rediscovers nature. As I have already said, the machine does not isolate man from the great problems of nature but plunges him more deeply into them.

de Saint-Exupery , Antoine ; de Saint-Exupery , Antoine ; Galantiere, Lewis . Wind, Sand and Stars: Wind, Sand and Stars (Harvest Book) by Antoine de Saint-Exupery and Lewis Galantiere . Mariner Books. Kindle Edition.


-------------------------------------------------------------------------------------------------------------------------------------------------------------

more on the genesis  and inspiration for the concept of the Perfect Machine      perfect-machine-inspiration.pdf


Paul Tofts
November 19th 2022