anatomy blood-vessels brain cardiovasculardiseases centralnervoussystem cerebralangiography cerebrovascularcirculation cerebrovasculardisorders congenitalabnormalities diagnosis doppler echocardiography female fetaldiseases generativeorgans genitaldiseases histology imageenhancement imaging magneticresonanceimaging methods nervoussystemdiseases neurovasculardiseases operative prenatal radiography stereotaxictechniques surgery surgicalprocedures three-dimensional three-dimensionalimaginginbiology ultrasonicimaging ultrasonicsinobstetrics ultrasonography wl141a2431998 wq209t5311997