Central signals of gallstones in magnetic resonance imaging

The magnetic resonance imaging of gallstones was studied in 34 patients. Diagnosis of the gallstones using magnetic resonance imaging was possible in 29 patients (85%). The gallstones showed as no-signal areas in all cases, with relatively strong signals being detected from the center of the stones in six cases. Postoperative studies showed the stones with the central signals to be of the so-called mixed stone type, in which the central area consists of cholesterol with a radiating structure. The central signal was thought to originate in water that accumulates in the central cavity of the stone, the cavity not being isolated from the exterior of the stone and there being a passage of fluids. The central signal is a characteristic indication of the stone's structure.