Pulmonary artery diameters, cross sectional areas and area changes measured by cine cardiovascular magnetic resonance in healthy volunteers.

BACKGROUND: We measured by cine cardiovascular magnetic resonance (CMR) main and branch pulmonary artery diameters and cross sectional areas in diastole and systole in order to establish normal ranges and the effects on them of age, gender and body surface area (BSA). Documentation of normal ranges provides a reference for research and clinical investigation in the fields of congenital heart disease, pulmonary hypertension and connective tissue disorders. METHODS: We recruited 120 healthy volunteers: ten males (M) and ten females (F) in each decile between 20 and 79 years, imaging them in a 1.5 Tesla CMR system. Scout acquisitions guided the placement of steady state free precession cine acquisitions transecting the main, right and left pulmonary arteries (MPA, RPA and LPA). Cross sections were rarely quite circular. RESULTS: From all subjects, the means of the greater and lesser orthogonal diastolic diameters in mm were: MPA, 22.9 ± 2.4 (M) and 21.2 ± 2.1 (F), RPA 16.6 ± 2.8 (M) and 14.7 ± 2.2 (F), and LPA 17.3 ± 2.5 (M) and 15.9 ± 2.0 (F), p < 0.0001 between genders in each case. The diastolic diameters increased with BSA and age, and plots are provided for reference. From measurements of minimum diastolic and maximum systolic cross sectional areas, the % systolic distensions were: MPA 42.7 ± 17.2 (M) and 41.8 ± 15.7 (F), RPA 50.6 ± 16.9 (M) and 48.2 ± 14.5 (F), LPA 35.6 ± 10.1 (M) and 35.2 ± 10.3 (F), and there was a decrease in distension with age (p < 0.0001 for the MPA). CONCLUSIONS: Measurements of MPA, RPA and LPA by cine CMR are provided for reference, with documentation of their changes with age and BSA.

Aortic root measurement by cardiovascular magnetic resonance: specification of planes and lines of measurement and corresponding normal values.

BACKGROUND: Cardiovascular magnetic resonance is widely used for aortic root visualization and measurement, but methods still need to be standardized. Our aim was to identify appropriate planes of acquisition and lines of measurement and record corresponding normal values. METHODS AND RESULTS: We studied 120 healthy volunteers, 10 of each gender in each decile between 20 and 80 years, by using a 1.5-T cardiovascular magnetic resonance system. Steady-state free precession cine acquisitions aligned with the left ventricular outflow tract in oblique sagittal and coronal orientations were used to locate 2 sinus planes that transected the root at its widest point in its maximally expanded systolic and at its end diastolic positions. We measured the cusp-cusp and the cusp-commissure dimensions in these cine planes, each as the average of 3. Diastolic cusp-commissure dimensions were smaller than diastolic cusp-cusp dimensions (32.0+/-3.5 mm versus 34.6+/-4.0 mm in men, 28.4+/-2.8 mm versus 30.7+/-3.3 mm in women, P<0.001 for both). The diastolic cusp-commissure dimensions increased by 0.9 mm per decade in men and 0.7 mm per decade in women (P<0.001 for both) and gave higher R(2) values with respect to age and body surface area (0.40 for men, 0.27 for women) than diastolic cusp-cusp, systolic cusp-commissure, or sinus measurements made in the left ventricular outflow tract planes. CONCLUSIONS: The results indicate the importance of consistent methods for measurement of the aortic root by cardiovascular magnetic resonance. We recommend diastolic cusp-commissure measurements, which yielded favorable R(2) values with respect to age and body surface area and were found to correspond closely with reference echocardiographic root measurements recorded in the Framingham cohort. We recorded reference values for these and other possible aortic root measurements by cardiovascular magnetic resonance.