> It is not a question of if but when

You can say that about almost anything, and the world is still full of factory workers.

As a PhD student in medical imaging, you must also know that getting fully automating segmentation methods to work to the standard required in the clinic is really hard. And once you solve it for one clinic you will likely not be able to transfer the trained model to another clinic, because scan parameters, patients and workflow are different.

But when we solve the segmentation task, I think most radiologist will clap their hands and move on.

I follow the progress in deep learning too, Radiologists have been close to out of a job since the 80's, but this time may be different. Deep conv nets have basically allowed computers to surpass us in identifying visual patterns. The bottleneck is just the training data.