How to Measure the Aorta Using MRI: A Practical Guide

Journal of Magnetic Resonance Imaging, vol. 52, pp. 971–977

Abstract

A ORTIC DIMENSIONS ARE IMPORTANT in the risk assessment of aortic pathology, aneurysms, dissection, and rupture.However, there is much debate on how, when, and where to measure the aorta.The main imaging techniques used to measure the aorta are transthoracic echocardiography (TTE), computed tomography (CT), and magnetic resonance imaging (MRI).MRI has the advantage over TTE and CT in that it is able to accurately visualize the entire aorta without using ionizing radiation and is able to give additional information on ventricular, valvular and vascular function and flow dynamics.Proximal aortic diameter measurements can vary up to 5 mm between imaging modalities, which can lead to relevant differences in clinical decisions about preventive surgery. 1 The American and European guidelines give recommendations on how to measure the aorta, but these recommendations differ and can be ambiguous.2,3 There are limited MRI guidelines on how to measure the aorta.1,4 Accordingly, still large variations exist in image acquisition and analysis in MRI. 5 The question is: how, when, and where do the guidelines advise us to measure the aorta?We will discuss aortic analysis in MRI and compare these to accepted practice in CT and TTE.This article provides recommendations for clinicians on aortic measurements in the adult population using MRI, with an emphasis on the thoracic aorta. How, When, and Where to MeasureHow: With or Without Aortic Vessel Wall?The normal ascending aortic vessel wall is ~2 mm thick, so inclusion of the wall can account for a 4-mm difference in aortic size.6 Echocardiography guidelines recommend the leading edgeto-leading edge (L-L) method (Fig. 1a) for measuring aortic diameters; consequently, the L-L method has been used in many trials that defined normal aortic size limits.1 Studies comparing multimodality imaging techniques have shown that the inner edge-to-inner edge (I-I) method (Fig. 1b-d) for MRI is in best agreement with the L-L method of echocardiography. 1 Given the high conformity with echocardiographic measurements and that with bright-blood MR angiography (MRA) techniques, only the equivalent of I-I measurements are obtained, and it View this article online at wileyonlinelibrary.com.

Authors 14

1. Max J. van Hout Aachen Department of Cardiology Leiden University Medical Center Leiden The Netherlands Department of Cardiology, Leiden University Medical Center

   Leiden University Medical Center

   Affiliation as printed

   Department of Cardiology Leiden University Medical Center Leiden The Netherlands

   Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands

2. Arthur J.H.A. Scholte Aachen Department of Cardiology Leiden University Medical Center Leiden The Netherlands Department of Cardiology, Leiden University Medical Center

   Leiden University Medical Center

   Affiliation as printed

   Department of Cardiology Leiden University Medical Center Leiden The Netherlands

   Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands

3. Joe F. Juffermans Aachen Department of Radiology Leiden University Medical Center Leiden The Netherlands Department of Radiology, Leiden University Medical Center

   Leiden University Medical Center

   Affiliation as printed

   Department of Radiology Leiden University Medical Center Leiden The Netherlands

   Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands

4. Jos J.M. Westenberg Aachen Department of Radiology Leiden University Medical Center Leiden The Netherlands Department of Radiology, Leiden University Medical Center

   Leiden University Medical Center

   Affiliation as printed

   Department of Radiology Leiden University Medical Center Leiden The Netherlands

   Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands

5. Liang Zhong

   National University of Singapore · SingHealth Duke-NUS Academic Medical Centre · Duke-NUS Medical School · National Heart Centre Singapore

   Affiliation as printed

   Cardiovascular Sciences Academic Clinical Programme, Duke‐NUS Medical School Singapore Singapore

   National Heart Centre Singapore National Heart Research Institute Singapore Singapore Singapore

   Cardiovascular Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore, Singapore

   National Heart Centre Singapore, National Heart Research Institute Singapore, Singapore, Singapore

6. Chao Zhou

   Eighth Affiliated Hospital of Sun Yat-sen University

   Affiliation as printed

   Department of Radiology Eighth Affiliated Hospital of Sun Yat‐sen University Shenzhen China

   Department of Radiology, Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, China

7. Simon M. Schalla

   Maastricht University Medical Centre

   Affiliation as printed

   Department of Cardiology Maastricht University Medical Centre Maastricht The Netherlands

   Department of Cardiology, Maastricht University Medical Centre, Maastricht, The Netherlands

8. Michael D. Hope

   University of California, San Francisco

   Affiliation as printed

   Department of Radiology University of California San Francisco California USA

   Department of Radiology, University of California, San Francisco, California, USA

9. Jens Bremerich

   University Hospital of Basel

   Affiliation as printed

   Department of Radiology Universitätsspital Basel Basel Switzerland

10. Christopher M. Kramer

    University of Virginia

    Affiliation as printed

    Cardiovascular Division, Department of Medicine University of Virginia Charlottesville Virginia USA

    Cardiovascular Division, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA

11. Marc Dewey

    Charité - Universitätsmedizin Berlin

    Affiliation as printed

    Department of Radiology Charité – Universitätsmedizin Berlin Berlin Germany

12. Karen Gomes Ordovas

    University of California, San Francisco

    Affiliation as printed

    Department of Radiology University of California San Francisco California USA

    Department of Radiology, University of California, San Francisco, California, USA

13. David A. Bluemke

    University of Wisconsin–Madison

    Affiliation as printed

    Department of Radiology University of Wisconsin Madison Wisconsin USA

    Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA

14. Hildo J. Lamb corresponding Aachen Department of Radiology Leiden University Medical Center Leiden The Netherlands Department of Radiology, Leiden University Medical Center

    Leiden University Medical Center

    Affiliation as printed

    Department of Radiology Leiden University Medical Center Leiden The Netherlands

    Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands