Effect of site and rate of contrast material injection on pulmonary vascular distention.
OBJECTIVE
The authors performed this study to determine if there were differences in vascular caliber measured on angiograms obtained with the injection protocol used for spiral computed tomography (CT) versus that used for pulmonary angiography.


METHODS
The authors studied seven juvenile anesthetized pigs by using a prospective repeated measures experimental design. All pigs received injections of nonionic contrast material via catheters in the brachial vein, superior vena cava, main pulmonary artery, and left pulmonary artery. Weight-adjusted injection rates and volumes ranged from 0.05 mL/kg/sec (3.5 mL/sec, spiral CT protocol) to 0.56 mL/kg/sec (40 mL/sec, pulmonary angiography protocol). Heart rate and pulmonary artery and systemic artery pressures were recorded. During each injection, identically positioned pulmonary angiograms were obtained at full inspiration. Vessel diameters were measured at identical locations after each injection by two observers. The relationship between vessel diameter and hemodynamic parameters and injection site and rate was assessed with analysis of variance.


RESULTS
At suspended full inspiration, no statistically significant difference (P > .05) in vessel diameter or hemodynamic parameters was found between the different injection sites or rates. There was no difference in vascular caliber between systole and diastole.


CONCLUSIONS
The improved detection of subsegmental pulmonary emboli at pulmonary angiography compared with contrast material-enhanced spiral CT is not due to differences in vascular distention.
Department of Radiology, Cliniques St Luc, Brussels, Belgium.
E
E
Coche
E M
EM
Baile
B
B
Wiggs
K I
KI
Kim
J R
JR
Mayo
D000792:Angiography / Q000379:methods; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D007091:Image Processing, Computer-Assisted; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D013552:Swine; D014057:Tomography, X-Ray Computed
D003287:Contrast Media