Evaluation of hydroxyethyl-starch-ferrioxamine as an intravascular MR contrast agent for assessment of myocardial perfusion.
OBJECTIVE
The present study was carried out to evaluate a new intravascular contrast agent hydroxyethyl-starch-ferrioxamine (HES-FO) for assessment of myocardial perfusion.


METHODS
Isolated pig hearts were perfused with a crystalloid cardioplegic solution in a Langendorff apparatus. MR images were acquired along the short cardiac axis using T1- and T2*-weighted methods. Gd-DTPA and HES-FO were used as the standard extracellular and test contrast agents, respectively.


RESULTS
We found that T1-weighted signal intensity was not significantly affected by HES-FO, but increased significantly in presence of Gd-DTPA. On the other hand, HES-FO resulted in a rapid, transient but significant decrease in T2*-weighted signal intensity. Although Gd-DTPA also decreased T2*-weighted signal intensity considerably, it took much longer for the T2*-weighted signal intensity to return to its initial steady-state with Gd-DTPA than with HES-FO. Moreover, increasing the dose of HES-FO (from 0.0023-0.0138 mmol/kg b.w.) had no effect on the time at which the T2* effect reached its maximum or on the duration of the T2* effect. However, these times and durations were affected significantly by increasing the dose of Gd-DTPA (0.0023-0.027 mmol/kg b.w.).


CONCLUSIONS
The results suggest that HES-FO provides information regarding myocardial vascular flow which cannot be obtained using Gd-DTPA. It is expected that the combined use of intravascular and extracellular type contrast agents will allow more complete assessment of tissue perfusion.
Tian
G
G
Institute for Biodiagnostics, National Research Council Canada, Winnipeg, MB, Canada.
Shen
J
J
Su
S
S
Kozlowski
P
P
Sun
J
J
Xiang
B
B
Saunders
J K
JK
Deslauriers
R
R
D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D003326:Coronary Circulation; D003676:Deferoxamine / Q000008:administration & dosage / Q000031:analogs & derivatives; D004338:Drug Combinations; D005290:Ferric Compounds / Q000008:administration & dosage; D005682:Gadolinium / Q000008:administration & dosage; D019786:Gadolinium DTPA; D006895:Hydroxyethyl Starch Derivatives / Q000008:administration & dosage; D066298:In Vitro Techniques; D018810:Magnetic Resonance Angiography / Q000379:methods; D009942:Organometallic Compounds / Q000008:administration & dosage; D004369:Pentetic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives; D010477:Perfusion / Q000379:methods; D013552:Swine; D013997:Time Factors
D003287:Contrast Media; D004338:Drug Combinations; D005290:Ferric Compounds; D006895:Hydroxyethyl Starch Derivatives; D009942:Organometallic Compounds; C002577:ferrioxamine B; D004369:Pentetic Acid; D005682:Gadolinium; D003676:Deferoxamine; D019786:Gadolinium DTPA