The ‘Disappearing’ Liver on CEUS: Nothing to Worry About

scattered tight pattern of hyperechoic areas (▶Fig. 3). The etiology of the phenomenon is still unknown and various hypotheses have been discussed: intestinal formation of unsheathed gas, bubble fusion or gas bubble pooling (Caruso G et al. Radiol Med (Torino) 2007; 112: 56–63; Shimada T et al. Ultrasound Med Biol 2012; 38: 1317–1323; Cui XW et al. Ultraschall Med 2014; 35: 246– 252). In all reported cases except one, the patients remained free of symptoms and liver enzymes were not reported to be altered. One patient experienced “general discomfort and a transient skin rush” during the infusion of the contrast media, before the appearance of PHLE (Tana C et al. Ultrasound Med Biol 2013; 39: 2214). After days, the US image of the liver is normal again in all patients. In the few patients that received a second portion of US contrast media days later, the phenomenon did not reappear. From the case series estimations, the incidence rate seems to be somewhere around 0.01–0.8 % of CEUS examinations. These rates are questionable and do not quite match the results from a recent oral survey among experienced German medical doctors, each having performed more than 1 000 CEUS investigations. Most of them were not aware of this side effect of contrast media.