Described herein is a process for the preparation of 6-fluorosteroids of formula, in which R is chosen from H, OH and an alkyl group with from 1 to 4 carbon atoms and R is a carboxyalkyl group with from 1 to 4 carbon atoms in the alkyl chain, comprising the selective fluorination at the 6-position . The large-area X-ray system can output a uniform flux of X-rays over a large area using discrete addressing operation of transistors connected to cathodes of electron emitters. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. , and optionally one or more components selected from a dispersant, a carbon fiber and water.