Yes, atomic radius in d block initially decreases then remains constant and finally increases at the end.
Over all trend can be explained based two factors that are working there, nuclear attractions and inter electronic repulsions, where one supports decrease in atomic radii and the other increase in atomic radii, respectively.
As we are moving from Sc to Zn , initially one factor nuclear charge increases as the new electrons coming and entering into same orbital that to inner one, as the number of electrons are low in the inner shell and the shielding power of d orbial is low, inter electronic repulsions will be operating less than nuclear charge, which results in decrease in atomic radii.
In the middle these two factors mostly operating equal, which results in consistency in size.
In the end, as the number of elections in the inner orbital increases the outer electrons feel better repulsions and slightly pushed away. though d orbital has less shielding power, the number of electrons are too high to make the electronic repulsion as more dominant factor at the end, which results in increase in the atomic radii.

						

							
Der student 
This is because initially the Nuclear charge increases like normal trend And hence the radii decreases continuously. From the midd
or ending of middle the Nuclear charge equates with the inter electronic repulsion and hence no such inc of radii takes place….
And finally Radii increasrd due to increase of inter electronic repulsions more than Zef f
This occurs in 3d,4d and 5d seried