Heartbeat-related distension and displacement of the thoracic aorta in healthy volunteers.
OBJECTIVE
To test our hypothesis that distension and displacement in various segments of the healthy thoracic aorta are significant and can be predicted based on clinical characteristics.


METHODS
Sixty-one Caucasian volunteers without cardiovascular disease (49 ± 16 years, range 19-82; 28 men, 33 women) divided into two age groups (A: <50, B: ≥ 50 years) underwent 1.5-T MRI. ECG-gated dynamic data sets were acquired at five locations perpendicular to the thoracic aorta. Aortic distension and Centre of Mass (CoM) displacement were determined as percentages of diastolic aortic diameter. A multiple linear regression model including age group, gender, location, mean arterial blood pressure, heart rate and body mass index was tested.


RESULTS
Mean aortic distension averaged over all locations was 11.2 ± 4.1% (age group A) and 6.7 ± 3.3% (age group B), mean displacement 15.1 ± 8.3% (A) and 11.0 ± 6.2% (B). Systolic and diastolic aortic diameter and CoM position significantly differed at all locations (p<0.001). Distension and displacement could be predicted based on the regression model (p<0.001). Age group A and women exhibited significantly greater distension and displacement compared to age group B (p<0.001) and men (p<0.01), respectively. Distension increased, displacement decreased from proximal to distal.


CONCLUSIONS
Distension and translational displacement are significant at all levels of the thoracic aorta and can be predicted based on clinical characteristics.
Rengier
Fabian
F
German Cancer Research Center (dkfz) Heidelberg, Department of Radiology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. f.rengier@dkfz.de
Weber
Tim Frederik
TF
Henninger
Verena
V
Böckler
Dittmar
D
Schumacher
Hardy
H
Kauczor
Hans-Ulrich
HU
von Tengg-Kobligk
Hendrik
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000502:physiology*; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D055119:Elastic Modulus / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult