[New aspects of radiologic pelvimetry. Digital image intensification radiography: preliminary results of validation possibilities and results in various types of pelvic disproportion].

Within 1 year with 1325 births 54 cases necessitated operative obstetric intervention due to a disproportion between fetal head and maternal pelvis. In 40 cases radiologic pelvimetry was performed, using the conventional technique. 75% of cases turned out to be due to a midplane or outlet contraction. As, on the one hand, this type of pelvic disproportion seems to be of increasing importance, on the other hand generously adoperated radiologic diagnosis is not well accepted by the patients due to X-ray burden, Digital Image Intensifier Radiography (DIR) has been introduced for pelvimetry. X-ray burden amounts to only 5% of that of the conventional technique. Enhanced postprocessing and interactive measurement possibilities are further advantages of DIR. Using the appropriate softwear, interactive measurement results are characterized by the lack of mistakes due to X-ray divergence, if only the distance between measurement level and desk surface is known. By analyzing 30 computer tomograms measurement levels of the most important pelvic distances could be calculated in relation to the position of the anterior iliac spine. These relations show a very low interindividual variation. Thus, possible errors in measurement amount to a maximum of only 3.5%. The evaluation of our cases reveals the necessity to reassess the normal ranges for pelvic parameters, for the use of those deriving from conventional pelvimetry failed to describe correctly the anatomy of birth channel. For this sake, additional measurements, esp. of sacral and pelvic outlet anatomy have to be performed. Based upon these measurements, a computer aided modelling of the birth channel and a simulation of the birth could be achieved.(ABSTRACT TRUNCATED AT 250 WORDS)