Dynamically identifying a stationary body of fluid (102) within a test volume by scanning within the volume can entail using a first part of a pulse sequence to acoustically interrogate a region within the volume to detect pre-existing movement (124) and, via a separate acoustic interrogation constituting the second part of the pulse sequence, acoustically interrogating the region to distinguish solid from fluid. The scanning is with both interrogations as a unit, so as to span the volume with the interrogations. The body is identified, dynamically based on an outcome of the interrogations. The scanning may span, for the identifying, a current field of view (116), including normal tissue, within an imaging subject. The procedure, from scanning to identifying, may be performed automatically and without need for user intervention, although the user can optionally change the field of view to further search for stationary fluid.
