Statistical properties of estimates of focal lesion detectability for medic
al ultrasonic imaging systems are investigated. Analytic forms for bias and
variance of estimates of detectability of a lesion consisting of fully dev
eloped speckle embedded within a speckle background are derived. Bias and v
ariance of estimates of detectability are investigated using a computer sim
ulation and experiments on tissue-mimicking phantoms. This work offers a sy
stematic methodology for interpreting measurements on phantoms in order to
assess lesion detectability. In addition, it provides useful results which
may be used to improve design of phantoms and experiments for imaging-syste
m performance assessment. (C) 1999 Acoustical Sociery ofAmerica. [S0001-496
6(99)01208-4].