Hello sir... I have MRI of cervical spine. My report is mild straighting of cervical curvature. Complete block of C4 and C5 vertebrae?

It appears that . The slight straightening may either suggest that your body was positioned in such a way that this came about or reflecting some muscle spasm. The block vertebra is a congenital or something you were born with which may also be a sign of other possible congenital issues in your spine or body so see a spine specialist if symptoms persist .
Let me explain. 1-straighting of the cervical spine comes from pain. 2-complete blockage at c4 c5 this means disc herniation or other causes made that blockage, this problem have to be take of it by neuro-surgeon.
Is this a comment? Not sure what your exact question is. But straightening of cervical curvature could either suggest cervical sprain with muscle spasms. Or most commonly it is seen because some MRI techs place patient;s neck on a pillow or not in neutral alignment during the MRI hence such findings in this case is iatrogenic and due to positioning. "complete block of c4 and c5 vertebrae" is non-descriptive phrase.