Three-dimensional magnetic resonance imaging for the study of ovarian function in a bovine in vitro model

Three-dimensional magnetic resonance imaging coupled with maximum intensity projection display, a technique usually reserved for magnetic resonance im aging angiography, is useful for the study of ovarian follicular growth. Th e ovaries of 19 cows were examined each day by transrectal ultrasonography. From these data, the precise phase of the ovarian cycle was determined and cows were ovariectomized on day 3 of wave one (n = 5), on day 6 of wave on e (n = 4), on day 1 of wave two (n = 4), greater than or equal to 17 days a fter ovulation (n = 5), and on the day of ovulation (n = 1). The excised ov aries were examined by magnetic resonance imaging using a fast imaging with steady state precession imaging sequence with maximum intensity projection reconstruction, displayed as a cine-loop of the ovaries rotating in space. This provided the dearest view among the three principal three-dimensional steady state data acquisition approaches tried; the follicles and other ov arian structures could be distinguished unambiguously. Results from the bov ine model indicate that the acuity of the three-dimensional fast imaging wi th steady state precession technique has potential application in in vivo i ntravaginal imaging in women for studying normal and pathological ovarian f unction.