[A technic of magnetic resonance tomographic pelvimetry in obstetrics]

Magnetic resonance imaging (MRL) allows for the first time direct determination of maternal pelvic dimensions without ionising radiation. Phantom measurements and the correlation with traditional pelvimetric measurements in 10 patients after Caesarean section have shown mean differences of +/- 2 mm, with a maximum of 5 mm. The evaluation of pelvic configuration is obtained analogous to the conventional roentgenogram. In addition to conventional or digital x-ray pelvimetry, the soft tissues of the maternal pelvis and the presenting part of the foetus is delineated with high contrast. Positioning in the body coil can be accomplished even late in pregnancy or in impending labour, acceptance by the pregnant women being high. Whereas in a given indication after delivery conventional x-ray pelvimetry continues to be performed, antenatally MRI pelvimetry has now been established in our Departments as the method of choice--based on meanwhile 107 examinations. Present drawbacks are the relatively high cost and the limited availability of MR units.