Significance of bolus time in first-pass radionuclide cardiography

✍ Scribed by Katalin Zámbo; Paul Gelinsky

• Book ID: 104651323
• Publisher: Springer
• Year: 1992
• Tongue: English
• Weight: 53 KB
• Volume: 19
• Category: Article
• ISSN: 0340-6997
• DOI: 10.1007/bf00173287

✦ Synopsis

Significance of bolus time in first-pass radionuclide cardiography

Dear Sir, We were extremely interested to read the very important article by Bell and Peters (1991) in which they demonstrated that the radionuclide technique for measuring blood flow from a first-pass study is independent of the bolus volume up to volumes of about 20 ml. However, if this technique is used to measure bolus volumes greater than 20 ml, the estimates of organ blood flow are not reliable.

We analysed the time relationship of a bolus during first-pass radionuclide cardiography using 550 MBq technetium-99m diethylene triamine penta-acetic acid (99mTc-DTPA) in 36 patients with cor pulmonale. The bolus time was characterized by bolus t25o/0 and calculated from a time-activity curve. The pulmonary circulation index (PCI), mean transit time (MTT) and pulmonary arterial pressure (PAP) were investigated to check the bolus quality. PCI is the time interval between the peaks of the time-activity curves of the right and left ventricles;

MTT was calculated from a peripheral pulmonary timeactivity curve using gamma-fit. PAP was measured by the microcatheter technique. We observed that bolus times shorter than 12 s yield significantly positive linear correlations between PCI and PAP (r = 0.61; P< 0.001) and MTT and PAP (r=0.67; P<0.001). There was no correlation between these parameters (PCI-PAP: r= 0.38; NS and MTT-PAP: r= -0.08; NS) when the bolus times were longer than 12 s.

Our results suggest that a bolus time up to about 12 s has no influence on blood flow.