Fierce 15 member Infraredx backed out of its planned $56 million IPO, citing "unfavorable market conditions." The company makes an imaging system combining ultrasound and near-infrared spectroscopy to detect a dangerous type of plaque which is associated with an increased risk of heart attack or stroke. The IPO plans were announced in January. The sale of 4 million shares was planned at a price between $13 and $15 apiece. More