1. A non-transitory processor-readable medium comprising instructions that, when performed by the processor, cause the processor to: construct a first image of a plane parallel to the surface of an ultrasonic imaging transducer, the plane corresponding to a locus at a specified depth within a first region of tissue, using information obtained from the imaging transducer; obtain information about a location of a vessel in the first image; obtain, from a second region of tissue, imaging information corresponding to loci in planes parallel to the surface of the transducer, the planes at depths automatically determined at least in part using the obtained information about the location of the vessel in the first image; automatically determine an adjusted depth corresponding to the location of the vessel in the second region including: determining a first depth using obtained imaging information indicative of a shallow boundary of the vessel, closer to the imaging transducer in depth than a deep boundary of the vessel; determining a second depth indicative of the deep boundary of the vessel; estimating a depth corresponding to the center of the vessel between the shallow and deep boundaries; and assigning the estimated depth as the adjusted depth; and construct a second image of a plane parallel to the surface of the transducer, the plane corresponding to the adjusted depth within the tissue; wherein the first and second regions are offset from each other.