A unique feature of the commercial delayed coking process is that the feed is introduced from the bottom of the coke drums and the coke formation begins at the bottom and proceeds to the top of the of the drum over 16-24 hour cycles. It is believed that the volatiles evolution during delayed coking generates channels and pores within the coke produced in the drums (1). The formation of these passages and pores in the delayed coker is believed to play an important role in the alignment and growth of anisotropic microstructures during the final stages of mesophase development. This alignment is very important for the production of needle coke by delayed coking of FCC decant oils (2). Both computer tomography (3) and nuclear magnetic resonance imaging (4) of petroleum cokes has been reported.