Scan alignment based on patient-based surface in medical diagnostic ultrasound imaging

A method for aligning scans from different times with a medical ultrasound imager, the method comprising:

• three-dimensionally scanning, by the medical ultrasound imager with a tracked transducer, a volume of a patient during a first appointment;
• determining a three-dimensional distribution represented by scan data from the three-dimensionally scanning during the first appointment and one or more lesions represented by the scan data;
• storing an image for the one or more lesions, and storing a location or locations for the one or more lesions and the three-dimensional distribution related to a first coordinate system;
• three-dimensionally scanning the volume of the patient during a second appointment different than the first appointment, the scanning being in a second coordinate system;
• registering the three-dimensional distribution with results from the scanning of the volume during the second appointment, thereby linking the first and second coordinate systems of the first and second appointments;
• and
• imaging of the one or more lesions during the second appointment, the one or more lesions located during the image in the second coordinate system guided by the lesion locations in the first coordinate system.

A method for aligning scans from different times with a medical imager, the method comprising:

• scanning a patient during a first period;
• determining a three-dimensional outside surface of the patient during the scanning of the first period;
• scanning the patient during a second period at least a day apart from the first period;
• determining a three-dimensional outside surface of the patient during the scanning of the second period;
• registering the three-dimensional outside surface of the patient from the first period with the three-dimensional outside surface of the patient from the second period;
• generating an image from the scanning the patient during the second period, the image based on the registering.