Contrast-enhanced cardiac MR imaging in the detection of reduced coronary flow velocity reserve.
OBJECTIVE
To prospectively evaluate the accuracy of contrast material-enhanced cardiac magnetic resonance (MR) imaging for determining impaired coronary flow velocity reserve (CFR) by using Doppler flow measurement as the reference standard.


METHODS
The study was approved by the institutional ethics committee, and all patients gave written informed consent. Eligible patients underwent contrast-enhanced cardiac MR imaging and invasive measurement of CFR. For contrast-enhanced MR imaging, a three-section single-shot saturation recovery gradient-recalled echo sequence with steady-state free precession was used. Sections were divided into six segments. For each segment, a transmural and subendocardial myocardial perfusion reserve index (MPRI) was calculated by using the upslope of the signal intensity-time curve during the first pass of contrast material at rest and during adenosine infusion (140 microg per kilogram body weight per minute). MPRIs of vascular regions were compared with the corresponding CFR. Receiver operating characteristic (ROC) analysis was performed to find the number of segments needed for best diagnostic accuracy of MPRI and to find a cutoff value for MPRI in the detection of a reduced CFR.


RESULTS
Thirty-five patients were evaluated (male-to-female ratio, 27:8; mean age +/- standard deviation, 63.5 years +/- 8.2; mean body mass index, 28.8 kg/m(2) +/- 3.8), and 43 vascular regions were analyzed. A linear correlation was found between the MPRI and CFR (r = 0.44, P < .05). The MPRI was significantly lower in vascular regions with a CFR of less than 2.00 than in regions with a CFR of 2.00 or greater (P < .05). Detection of a CFR of less than 2.00 was more accurate with subendocardial MPRI measurements than with transmural measurements. The mean subendocardial MPRI of the segments with the three lowest MPRIs of a vascular region showed the best diagnostic performance in the detection of a CFR of less than 2.00 (area under the ROC curve, 0.85; sensitivity, 84%; specificity, 75%) by using a cutoff value of 1.21.


CONCLUSIONS
The diagnostic accuracy of subendocardial perfusion analysis in contrast-enhanced cardiac MR imaging is higher than that of transmural analysis.
Barmeyer
Achim A
AA
Clinic of Cardiology/Angiology, Heart Center, University Hospital Hamburg-Eppendorf, Martini-strasse 52, 20246 Hamburg, Germany. barmeyer@uke.uni-hamburg.de
Stork
Alexander
A
Muellerleile
Kai
K
Tiburtius
Claudia
C
Schofer
Anne K
AK
Heitzer
Thomas A
TA
Hofmann
Thomas
T
Adam
Gerhard
G
Meinertz
Thomas
T
Lund
Gunnar K
GK
D003287:Contrast Media; D003324:Coronary Artery Disease / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003331:Coronary Vessels / Q000473:pathology*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives*; D008875:Middle Aged; D009942:Organometallic Compounds; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology
D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine