ARTIFACTS AND INTRAVASCULAR ULTRASOUND IM AGING - ANALYSIS AND IMPLICATIONS FOR MORE RELIABLE IMAGE INTERPRETATION AND MORE ACCURATE MEASUREMENTS

Intravascular ultrasound catheters provide cross-sectional images of v essel walls and surrounding tissues with rotating transducers, and the behavior of ultrasound in heterogeneous media both cause degradation of image quality. Qualitative and quantitative analyses of in vivo stu dies are operator-dependent and limited by artifacts. We investigated these limitations by an in vitro study on plexiglass phantoms and segm ents of fresh arteries. We observed, analyzed and interpreted the most specific reasons for image artifacts : geometric distortions, the poi nt spread function of the imaging system and the near field effects. V arious practical implications have resulted from this study. Knowledge of the most obvious pifalls will enable the user to obtain maximum be nefits from intravascular ultrasound imaging, and to appreciate its li mitations.