Heart failure: evaluation of cardiopulmonary transit times with time-resolved MR angiography.
OBJECTIVE
To measure cardiopulmonary transit times in patients with heart failure by using low-dose, time-resolved magnetic resonance (MR) angiography and to determine if transit curves reflect conventional MR indexes of cardiac function.


METHODS
Twenty-six patients with heart failure and left ventricular (LV) systolic dysfunction (17 men and nine women; age range, 22-78 years) and thirteen control subjects (eight men and five women; age range, 23-59 years) were examined with MR imaging. The examination consisted of rapid cine MR imaging throughout the heart, followed by contrast material-enhanced time-resolved three-dimensional MR angiography of the cardiac chambers and pulmonary vasculature. Time-intensity curves for the pulmonary artery and ascending aorta were derived from the MR angiography images. Cardiopulmonary transit times and dispersions (full widths at half maximum [FWHM]) were determined from the curves. Transit times and FWHM values for the patients with heart failure were compared with control values by using two-tailed t tests, and transit time was correlated with standard LV functional parameters calculated from the cine MR images.


RESULTS
Cardiopulmonary transit times and FWHM values were significantly prolonged in the patients with heart failure compared with those in the control patients (P <.001). Transit time correlated directly with LV end-diastolic and end-systolic volumes and inversely with LV ejection fraction (R > 0.60). However, transit time did not correlate strongly with age, body surface area, heart rate, LV mass, stroke volume, cardiac output, or sphericity index.


CONCLUSIONS
Time-resolved MR angiography allows determination of cardiopulmonary transit times that are significantly prolonged in heart failure and correlate directly with LV volumes and inversely with LV ejection fraction.
Shors
Stephanie M
SM
Department of Radiology, Division of Cardiology, Feinberg School of Medicine, Northwestern University Medical School, Chicago, IL, USA.
Cotts
William G
WG
Pavlovic-Surjancev
Biljana
B
François
Christopher J
CJ
Gheorghiade
Mihai
M
Finn
J Paul
JP
D000328:Adult; D000368:Aged; D001776:Blood Circulation Time; D002306:Cardiac Volume; D006321:Heart / Q000503:physiopathology*; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000502:physiology