Any forecasting system, from quake prediction to cancer screening, can be analysed in the same way once the base-rate and accuracy figures are given.

Conclusion fetal echocardiography showed high sensitivity and accuracy in the diagnosis of congenital heart diseases, and is of great value in prenatal screening of fetal congenital diseases.

TCCD and PDI highly increased the accuracy in the examination of the intracranial vessels. TCD plays an important role in screening for cerebral angiography.