Coronary MR imaging: effect of timing and dose of isosorbide dinitrate administration.
OBJECTIVE
To quantify the effect of sublingual isosorbide dinitrate (ISDN) administration on coronary magnetic resonance (MR) imaging.


METHODS
Written informed consent was obtained from all participants, and the HIPAA-compliant protocol was approved by the Institutional Review Board. Coronary MR imaging was performed at 1.5 T before and after administration of ISDN (2.5 or 5 mg) in 25 healthy adult volunteers (mean age, 23 years +/- 4; nine men, 16 women) with three-dimensional targeted (n = 20, randomized into four groups) or whole-heart (n = 5) acquisitions with gradient-recalled echo (GRE) or balanced steady-state free precession (SSFP) sequences. Image quality was assessed by two cardiologists on a four-point scale. Signal-to-noise ratio (SNR), vessel diameter, and vessel sharpness were characterized. A linear mixed-effects model was used for data analysis. A P value of less than .05 was considered to indicate a significant difference.


RESULTS
The maximum SNR enhancement with 5 mg of ISDN (GRE: 22.0% +/- 10.7%; SSFP: 20.1% +/- 6.0%) was similar (P > .05) to that with 2.5 mg (GRE: 21.9% +/- 5.4%; SSFP: 19.1% +/- 3.0%). However, the time to maximum SNR enhancement for the 5-mg dose (15.5 minutes +/- 6.0) was earlier (P < .01) than that for 2.5 mg (23.5 minutes +/- 6.7). The increase in vessel diameter with 5 mg of ISDN was greater than that with 2.5 mg (P < .05 for both GRE and SSFP sequences). The coronary images were sharper after ISDN administration (P < .03). Subjective image quality score significantly improved after ISDN administration for GRE images (P < .05 for both doses) but was similar for SSFP images (P = .24 for 2.5 mg; P = .27 for 5 mg). Whole-heart coronary SNR was improved about 10% after ISDN administration (P < .05).


CONCLUSIONS
Sublingual ISDN improves coronary MR imaging SNR. Practitioners need to consider the dose and temporal effects of ISDN when performing coronary MR imaging.
Hu
Peng
P
Cardiovascular Division, Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Ave, Boston, MA 02215, USA.
Chuang
Michael L
ML
Ngo
Long H
LH
Stoeck
Christian T
CT
Peters
Dana C
DC
Kissinger
Kraig V
KV
Goddu
Beth
B
Goepfert
Lois A
LA
Manning
Warren J
WJ
Nezafat
Reza
R
D000286:Administration, Sublingual; D003331:Coronary Vessels / Q000033:anatomy & histology*; D005260:Female; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007548:Isosorbide Dinitrate / Q000008:administration & dosage*; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D014665:Vasodilator Agents / Q000008:administration & dosage*; D055815:Young Adult
D014665:Vasodilator Agents; D007548:Isosorbide Dinitrate