Mean Thoracic Aortic Wall Thickness Determination by Cine MRI with Steady-State Free Precession: Validation with Dark Blood Imaging

doi:10.1016/j.acra.2013.03.014

Academic Radiology

Volume 20, Issue 8, August 2013, Pages 1004-1008

https://doi.org/10.1016/j.acra.2013.03.014 Get rights and content

Rationale and Objectives

To assess the validity and reliability of measuring mean aortic wall thickness (MAWT) of the ascending and descending aorta using cine steady-state free precession (SSFP) imaging compared to dark blood (DB) imaging.

Materials and Methods

DB and SSFP images of the thoracic aorta acquired at 1.5 T in 50 volunteers (26 women, 24 men; mean age: 50.2 ± 13.1 years) were used. MAWT was calculated on DB and SSFP images for the ascending and descending aorta at the level of the right pulmonary artery by two independent observers. Validity was assessed using Bland-Altman analysis, Passing-Bablok regression, and Spearman correlation. Reliability was assessed using Bland-Altman analysis and intraclass coefficients (ICCs).

Results

The mean MAWT of the ascending aorta on DB and SSFP images was 1.89 ± 0.21 mm and 1.87 ± 0.20 mm. The measurements for the descending aorta were 1.60 ± 0.22 and 1.63 ± 0.20 mm, respectively. Comparison of DB and SSFP measurements revealed a mean bias of 1.3% (95% limits of agreement (LOA): −7.9, 10.5%) for the ascending and of −2.1% (LOA: −10.5, 6.3%) for the descending aorta. The corresponding regression equation was y = 0.042 + 0.960 × (r = 0.91; P < .0001) and y = 0.118 + 0.939 × (r = 0.95; P < .0001), respectively. Intra- and interobserver variability showed a mean bias of less than 2.0% and LOA of less than ±15.0%. ICCs were greater than or equal to 0.85.

Conclusions

MAWT determination in the ascending and descending aorta using cine SSFP sequences is highly valid and reliable compared to DB imaging.

Section snippets

Study Population

The study was approved by the institutional review board, and written informed consent was obtained from each participant before enrollment.

This prospective study included healthy subjects without absolute or relative contraindications to MRI such as pacemaker, non–MR-compatible implants, and pregnancy. Subjects without sinus rhythm were not included in this study.

Fifty volunteers, 26 women and 24 men, with a mean age of 50.2 ± 13.1 years were enrolled in this study.

Imaging Protocol

MRI was performed in a

MAWT of Ascending and Descending Aorta

One MAWT measurement of the ascending aorta could not be performed due to poor visualization of the aortic wall in the DB sequence. Thus, 49 image datasets for the ascending and 50 datasets for the descending aorta were analyzed.

The median trigger time of the DB and SSFP sequence was 645.0 ms (IQR: 585.0–722.5 ms) and 653 ms (IQR: 587.5–721.0 ms), respectively. The difference was not statistically significant (P = .780).

The mean MAWT of the ascending aorta on DB and SSFP images was 1.89 ±

Discussion

The results of this study indicate that determination of MAWT in the ascending and descending aorta using cine SSFP sequences is valid and reliable compared to DB imaging although cine SSFP MRI has lower spatial resolution.

MRI using DB imaging is a feasible technique for the determination of aortic wall thickness with high interobserver agreement (9). The DB technique highlights the aortic wall by enhancing contrast between the hyperintense wall and the dark lumen through suppression of the

Conclusion

In conclusion, MAWT determination in the ascending and descending aorta using a cine SSFP sequence yields valid and reliable results when compared to the well-established DB imaging technique. Because cine imaging is an integral part of every cardiac MRI protocol, its use for MAWT measurement allows routine clinical determination of this important parameter.

References (14)

V. Mani et al.
Cardiovascular magnetic resonance parameters of atherosclerotic plaque burden improve discrimination of prior major adverse cardiovascular events
J Cardiovasc Magn Reson
(2009)
E.B. Rosero et al.
Sex, race, and age distributions of mean aortic wall thickness in a multiethnic population-based sample
J Vasc Surg
(2011)
J.M. Bourque et al.
Usefulness of cardiovascular magnetic resonance imaging of the superficial femoral artery for screening patients with diabetes mellitus for atherosclerosis
Am J Cardiol
(2012)
N.G. Keenan et al.
Magnetic resonance of carotid artery ageing in healthy subjects
Atherosclerosis
(2009)
F. Weidinger et al.
Association of wall thickness of the brachial artery measured with high-resolution ultrasound with risk factors and coronary artery disease
Am J Cardiol
(2002)
G.L. Burke et al.
Arterial wall thickness is associated with prevalent cardiovascular disease in middle-aged adults. The Atherosclerosis Risk in Communities (ARIC) Study
Stroke
(1995)
M.L. Bots et al.
Common carotid intima-media thickness and risk of stroke and myocardial infarction: the Rotterdam Study
Circulation
(1997)

There are more references available in the full text version of this article.

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: The authors declare that they have not received any grants or funding supporting the research.

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Original InvestigationMean Thoracic Aortic Wall Thickness Determination by Cine MRI with Steady-State Free Precession: Validation with Dark Blood Imaging

Rationale and Objectives

Materials and Methods

Results

Conclusions

Section snippets

Study Population

Imaging Protocol

MAWT of Ascending and Descending Aorta

Discussion

Conclusion

J Cardiovasc Magn Reson

J Vasc Surg

Am J Cardiol

Atherosclerosis

Am J Cardiol

Arterial wall thickness is associated with prevalent cardiovascular disease in middle-aged adults. The Atherosclerosis Risk in Communities (ARIC) Study

Stroke

Common carotid intima-media thickness and risk of stroke and myocardial infarction: the Rotterdam Study

Circulation

Original Investigation
Mean Thoracic Aortic Wall Thickness Determination by Cine MRI with Steady-State Free Precession: Validation with Dark Blood Imaging