Magnetic resonance coronary angiography: comparison between a Gd-BOPTA- and a Gd-DTPA-enhanced spoiled gradient-echo sequence and a non-contrast-enhanced steady-state free-precession sequence.
BACKGROUND
Several studies have demonstrated that the administration of contrast agents is advantageous in magnetic resonance coronary angiography (MRCA).


OBJECTIVE
To compare a non-contrast-enhanced steady-state free-precession (SSFP) with a contrast-enhanced inversion recovery spoiled gradient-echo (IR-GE) sequence using two different contrast agents for MRCA.


METHODS
Eight healthy volunteers were examined on a 1.5T MR scanner. For non-contrast-enhanced MRCA, a breath-hold three-dimensional (3D) SSFP sequence (repetition/echo time [TR/TE] 3.9/1.7 ms, flip angle [FA] 65 degrees) was used. Contrast-enhanced MRCA was performed repetitively in two imaging sessions over 30 min after injection of 0.2 mmol/kg body weight gadobenate dimeglumine (Gd-BOPTA) or gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) using a breath-hold 3D IR-GE sequence (TR/TE 4.1/1.7 ms, FA 15 degrees). The signal-to-noise ratios (SNR) of the coronary arteries, as well as the contrast-to-noise ratios (CNR) between coronary arteries and perivascular tissue, were calculated for all images. Blood T (1) values were repetitively estimated over 30 min using an SSFP sequence with incrementally increasing inversion times (TR/TE 2.4/1.0 ms, FA 50 degrees).


RESULTS
Gd-BOPTA-enhanced images showed significantly (P<0.05) higher SNR and CNR compared to Gd-DTPA-enhanced images for all times after contrast injection (SNR: 1 min post injection [PI] 26.4+/-4.2 vs. 16.2+/-3.1; CNR: 1 min PI 21.4+/-3.7 vs. 13.2+/-2.6). Compared to the SSFP images, the Gd-BOPTA-enhanced images showed higher CNR values for all times after injection (1 min PI 21.4+/-3.7 vs. 13.8+/-5.5; P<0.05), whereas the Gd-DTPA-enhanced images did not (1 min PI 13.2+/-2.6 vs. 13.8+/-5.5; P>0.05). Blood T (1) estimates were not significantly different for either agent 1 min after administration (P>0.05), but they were significantly lower for Gd-BOPTA (P<0.05) from 7 to 25 min after injection.


CONCLUSIONS
Compared to non-contrast-enhanced SSFP images, only Gd-BOPTA-enhanced images show a significantly improved contrast between the coronary arteries and the surrounding tissue.
Nassenstein
K
K
Department of Diagnostic and Interventional Radiology and Neuroradiology, West German Heart Center Essen, University Hospital Essen, Essen, Germany. kai.nassenstein@uni-due.de
Breuckmann
F
F
Hunold
P
P
Barkhausen
J
J
Schlosser
T
T
D000328:Adult; D003287:Contrast Media; D017023:Coronary Angiography; D005682:Gadolinium; D019786:Gadolinium DTPA; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives*; D009942:Organometallic Compounds
D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine; D005682:Gadolinium; D019786:Gadolinium DTPA