Still in thinking - MRI - Zoology - Creative Commons License CC-BY-NC-SA

I am releasing all the ideas here , under Creative Commons License CC-BY-NC-SA as explained here.
Most of the MRI considering only hydrogen atom. But, the true potential of MRI can be used in many ways. The idea is already in practice in NMR. The required frequencies are already found , and tabulated here. Thanks to pypulsar . I am putting some of my ideas here again under CC-BY-NC-SA.
This idea is derived from this. Please read it to understand the concept.
Scan the nail samples, and tusk samples of an elephent in various time intervals using MRI. By comparing these MRI scans , we can say in how much years that elephent's tusk will grow into certain length. The same goes to rhino horn,deer's antler,etc.
By measuring it with a tap is easier way, but it is hard to measure a slow growing thing. we have to wait for months to measure a considerable growth. And there would be muscles and skin around the tusk that would make the measurement inaccurate. But these mistakes are not possible in this MRI based method. Three samples in three weeks is enough in this method to measure the growth, and calculate it for the future.