Fig. 1.

Arterial (solid line) and venous (dotted line) time-intensity curves acquired from a 66-year-old female.

A. For the test-bolus study, 2 ml of contrast medium was injected at a rate of 3 ml / sec. Tae, Tp, Tve, and ED were 13, 18, 35, and 17 seconds, respectively. The calculated values of Tav and EER obtained from the above data were 22 sec and 25.76.

B. For the main-bolus study, 12 ml of contrast medium was injected at a rate of 3 ml / sec. Tae, Tp, and Tve were 14, 25, and 36 seconds, respectively, and Tav was 22 sec. ED could not be measured on this graph due to the uncertain end-point of enhancement. It is certain, however, that the duration of arterial enhancement was markedly greater (4 secs) than that of the infusion of contrast media. Tae = Arterial enhancement time, Tp = Arterial peak enhancement time, Tve = Venous enhancement time, ED = Enhancement duration, Tav = Arteriovenous circulation time, EER = Enhancement expansion ratio.