Ultrasonic guidance of a needle path during biopsy

An ultrasonic imaging system which visually guides the insertion of an invasive device such as a needle, the system comprising:

• an ultrasound probe having an array transducer for imaging a region of tissue containing target tissue and producing received signals;
• an ultrasound system processing signals received by the ultrasound probe to produce a set of spatially identified pixels having pixel values proportionate to the received signals;
• an image processor responsive to the pixel values which produces an ultrasound image;
• a display which displays the ultrasound image;
• a tissue density analyzer, responsive to the pixel values, which produces an estimate of tissue density based on the spatially identified pixels corresponding to a path of invasive device insertion,
• wherein the estimate of tissue density is displayed on the display.