In accordance with a method for characterization of particles in a fluid-filled hollow structure, an ultrasound signal with a frequency spectrum, which exhibits a local maximum at a variable measurement frequency, is emitted in the direction of a part area of the hollow structure and reflected components are detected. The measurement frequency is tuned in a predetermined measurement interval, and depending on the detected reflected components, a spectral response curve is acquired as a function of the measurement frequency. Depending on the response curve, at least one characteristic property for a part of the particles located in the part area of the hollow structure is determined. The characteristic property includes a measure for an adhesion of the particles of the part of the particles located in the part area of the hollow structure.