<prompt> Duplex ultrasonography combines:A-mode imaging and pulse-wave Doppler examinationB-mode imaging and pulse-wave Doppler examinationM-mode imaging and power Doppler examinationM-mode imaging and waveform analysis  <response>: Ans. B. B-mode imaging and pulse-wave doppler examinationAn objective assessment of the severity of disease is obtained by noninvasive techniques. These include digital pulse volume recordings, doppler flow velocity waveform analysis, duplex ultrasonography which combines b-mode imaging and pulse-wave doppler examination, segmental pressure measurements, transcutaneous oximetry, stress testing usually using a treadmill, and tests of reactive hyperemia. 