Piper Jaffray analyst William Quirk attributes the post-earnings weakness today in shares of Quest Diagnostics to a "messy" outlook for 2018. The guidance reads as lower revenue growth, but higher earnings, Quirk tells investors in a research note. He believes the 4%-5% revenue growth is reasonable with the legal resolution for the Protecting Access to Medicare Act coming as soon as mid-year. Quirk raised his price target for Quest shares to $110 and keeps a Neutral rating on the name. The analyst finds the shares fairly valued relative to the company's growth rate.