However, annulus measurements have become increasingly important with the growing use of transcatheter-implanted aortic valves. 2013;200 (6): W581-92. Fig. 1 —Coronal oblique CT angiographic image of healthy 64-year-old man depicts ascending aortic anatomic landmarks that are typically reported for measurement purposes. Fig. 9). CT is currently the best non-invasive modality for simultaneous assessment of coronary anatomy as part of aortic root evaluation. An aortic root aneurysm is a type of aneurysm that occurs in the aorta — the body's largest blood vessel. imaging in - Marfan's disease - Bicuspid aortic valve disease / aneurysm 12), although acquisitions sometimes suffer from the unpredictable “dark band artifact” caused by dephasing of spins. Corresponding Author. ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. If gating is poor or the examination is ungated, a statement should be made regarding the quality of the images and impression of measurement precision. 2. There are multiple reports of aortic dissection at an internal aortic diameter of less than 50 mm. 5). 1. – Consecutive patients with dilated aortic root or ascending aorta identified by echo or CT (2003-2007) – Followed a mean of 10.8 years – 327 patients with a tricuspid aortic valve and aortic diameter 4.5-5.5 cm – 44% had an aortic root area/height ratio ≥10 • 78% died • Aortic surgery associated with improved survival. However, conventionally cardiac and proximal aortic abnormalities were only seen on dedicated cardiac or aortic studies due to need for ECG gating. [22] and Zilocchi et al. Because the M-mode cannot show spatial relationships of structures, it has been supplanted by 2D echocardiography for investigation of aortic disease. 3.1). One approach is to use ECG-gated 2D balanced SSFP sequences oriented perpendicular to the aortic root in two planes to assess the aortic valve and root throughout the cardiac cycle and additionally to use high-resolution 3D contrast-enhanced MRA to assess the remainder of the aorta. Normal anatomy of the aortic root at cardiac CT performed with ECG gating on a 64-channel dual-source scanner. Inter- and intraobserver correlations for aortic root and aortoiliac measurements were high (r = 0.93-0.99). Measurements in this view have been the basis for surgical decision making (Table 2) because of the outcome data that have been published with that approach. 10). Patients with BAV, a family history of early dissection, aortic coarctation, small adult body size (ratio of aortic area to body height > 10 cm2/m), or a concomitant need for other cardiac surgery may be advised toward elective surgical intervention at ascending aortic diameters as small as 40 mm [39, 42]. The If there is asymmetric aortic root enlargement, this measurement may not yield the largest sinus diameter and does not account for whether the aneurysm is occurring in one or more sinuses (Fig. The recommended cutoff for elective surgical intervention of ascending aortic dilatation in a patient without another underlying cardiovascular abnormality or disease, such as a connective tissue disorder, is 55 mm. The anatomy of the aortic root includes the annulus, sinuses of Valsalva, sinotubular junction and ascending aorta [ 1 ], with the size being a function of a patient’s biologic variables such as height, age, BSA, and gender [ 1, 2 ]. This follow-up may be extended to annual evaluation with documented stability. We also discuss findings that can assist in preoperative planning and in … The aortic root is the anatomical bridge between the left ventricle and the ascending aorta. When interpreting CT and MRI, radiologists should actively screen for and recognize features suggestive of an underlying connective tissue disorder. 3D and 4D Imaging of the Aortic Root Learning Objectives / Outline • Technique: 'gated chest' CT • Surgical anatomy of thoracic aorta • Clinical pre- and postop. During systole, the outward pouches act as support for the leaflet cusps. Aneurysms of the sinuses of Valsalva are relatively rare and can be congenital or acquired. Gated computed tomography (CT) might not adequately predict occurrence of post-implantation transcatheter aortic valve replacement (TAVR) complications in hostile aortic root as it would require a more complex integration of morphological, functional and hemodynamical parameters. Parasternal long-axis image measurement of 3.36 cm (A) does not accurately represent patient's quadricuspid aortic valve (asterisks) and does not display aneurysm of accessory sinus of Valsalva (arrow, B) between right and noncoronary sinuses, which has ruptured into right atrium. The aortic root and valve were inspected by the surgeon and based on the AR mechanism, classified as type 1 (AR due to aortic root dilation), type 2 (AR due to cusp prolapse), or type 3 (AR due to cusp restriction). The aortic root is an ensemble consisting of distinct entities: the aortic valve leaflets, the leaflet attachments, the sinuses of Valsalva, the interleaflet trigones, the sinotubular junction and the annulus (14,16-18) . The reported prevalence of thoracic aortic aneurysms is 4.2% in individuals without predisposing factors; however, the true prevalence is likely greater because thoracic aortic aneurysmal disease often remains asymptomatic—and undiagnosed—until a catastrophic complication occurs [2]. Multimedia Manual of Cardiothoracic Surgery 2006. Cardiac pulsation and motion of the aortic root frequently make accurate measurements impossible otherwise. BAV morphologies may predict associated patterns of aortic dilatation. Sinus measurements obtained in this view usually correlate roughly with the measurement from the right sinus to the noncoronary sinus. For evaluation of the aortic root and ascending aorta, the best results are obtained with ECG gating. We also discuss findings that can assist in preoperative planning and in detecting underlying connective tissue disorders. However, ECG-gated CT has drawbacks, including radiation exposure to patients. However, normalization of z scores to body surface area is beyond the scope of most radiology practices and in this practice can be left to the referring clinician if patient height and estimated body surface area are not readily available. BAV is inherited in an autosomal-dominant pattern with variable penetrance. Like CT, MRI can be performed with ECG-gated sequences to provide motion-free assessment of the aorta. Dist = distance between cursors. C, Echocardiogram obtained at our institution shows mid ascending aorta (cursors) measures 5.3 cm—below threshold for surgical intervention. Attention must be paid to the length of aortic dilatation, growth greater than 5 mm/y, the presence of aortic regurgitation, and a family history of aortic dissection at a diameter of less than 50 mm because these factors predict a poorer prognosis and may prompt earlier repair [17]. How I Do It: CT Pulmonary Angiography, MR Imaging Differentiation of Soft-Tissue Hemangiomas from Malignant Soft-Tissue Masses, Review. Fig. It fills with blood during diastole, supplying the coronary arteries with oxygen-rich blood. The semilunar leaflet insertions take the course of a three-pronged coronet rather than forming a ring as implied by the term annulus. B, Sagittal oblique thin maximum-intensity-projection unenhanced MR angiographic image of thoracic aorta. Introduction. Figure 1 Normal aortic root anatomy in a 35-year-old man with chest pain referred for CT coronary angiography. However, measuring the ascending aorta and assessing changes over time can be challenging when comparing the results of different imaging modalities or even examinations of a single modality. Approximate echo window is reproduced in white. Testicular Cancer: What the Radiologist Needs to Know, Review. The aortic root lies between the junction of the aortic valve and ascending aorta. Patient had history of thymectomy, mediastinal radiation, and prior mitral valve replacement. Standardized locations within the aortic root and ascending aorta from which measurements are taken should be established and measurements should be obtained perpendicular to the direction of blood flow in a 3D viewer. We also recommend reporting of series and image slice numbers with each measurement to allow accurate and precise reassessment when future studies are performed. A 33-year-old male with a history of intravenous drug abuse with infectious endocarditis status post … In Marfan syndrome, the primary genetic abnormality is a mutation in the FBN1 gene that encodes for glycoprotein fibrillin [19], although variant genotypes and phenotypes are increasingly observed. Check for errors and try again. The aortic root anatomy is described in Figure 2. 2013;2 (1): 53-6. A standardized approach to the measurement of the aorta is needed and features suggestive of an underlying connective tissue disorder should be recognized. If the largest measurement does not correspond to one of these locations, the largest dimension should be also reported. As the disease progresses, the annulus expands, which may result in poor aortic cusp coaptation and aortic regurgitation [20]. CT angiography was evaluated to determine aortic valve reparability. [38] compared cusp-commissure dimensions in the sinus planes with the corresponding cusp-cusp measurements; they found that cusp-commissure dimensions in the sinus planes were 2–3 mm smaller than cusp-cusp measurements but corresponded more closely with reference echocardiographic aortic root measurements in the Framingham Heart Study [30]. Objectives: The aim of this study is to investigate the sex-specific aortic root anatomy in patients with bicuspid aortic valve (BAV). The aortic valve is normally a tricuspid structure that separates the aorta from the left ventricle, thus preventing diastolic retrograde flow into the ventricle. The three aortic root sinuses or sinuses of Valsalva are functionally identical. A, Double oblique reformatted 3D balanced steady-state free precession MR image obtained with prospective ECG gating and respiratory navigation provides high-resolution, motion-free image of sinuses of Valsalva in cross section. Additional measurements should be given for the aortic arch and descending aorta. A standard operative approach to obtain access to the ascending aorta is through a median sternotomy. 4). 14‑1). They often have no symptoms and doctors find them during x-rays or CT scans. The method of measurement should be clear in the report so that any ambiguity or discrepancy with previous measurements using a different technique or modality can be explained. B, CT angiographic reformation image in three-chamber view equivalent to A reproduces measurement (blue line) performed at echocardiography. 10 —24-year-old woman with aneurysm. A BAV occurs in up to 2% of the population, and BAV is the most common congenital heart disease [12]. (2000) Heart (British Cardiac Society). In addition, for women with Marfan syndrome contemplating pregnancy, many physicians prophylactically replace the aortic root and ascending aorta when the diameter exceeds 40 mm [15]. Although they are not specifically addressed by the guidelines as a distinct entity, aneurysms of the sinuses of Valsalva may have a different clinical presentation and management issues may be more complex. Underwood MJ, El Khoury G, Deronck D, Glineur D, Dion R. The aortic root: structure, function, and surgical reconstruction. 2015;28 (2): 119-82. In contradistinction to aortic dissection in patients with Marfan syndrome, aortic dissection in patients with Loeys-Dietz syndrome occurs earlier, both temporally and in terms of aneurysm size. ABSTRACT : OBJECTIVE. 9–11), whereas some investigators report inner diameter–to– inner diameter measurements [37]. Loeys-Dietz syndrome is an inherited condition that results from an underlying mutation in transforming growth factor–β receptors [21]. At the UPMC Heart and Vascular Institute , we offer complete cardiovascular care. When these features are present, the radiolo-gist may be the first to suggest the possibility of a heritable disease that may dramatically impact management decisions. Even in published guidelines, there is a lack of consistency in the approach for measuring aortic diameter—across modalities, planes, and anatomic landmarks and in the timing during the cardiac cycle. METHODS: We used 26 specimens of normal hearts and 78 CT data sets of adults with a mean age of 64±15 years to measure the dimensions of the membranous septum and to assess any influence played by rotation of the aortic root, inferring the relationship to the atrioventricular conduction axis. 6 Valve-sparing aortic root reconstruction was considered a feasible option in most type-1 and type-2 ARs unless heavy calcification of the aortic valve. Another challenge to the use of aortic measurements is that the measurement and imaging techniques reported are not consistent across studies in the literature. The base o… This image was used to select valve prosthesis and plan implantation procedure, and 24-mm prosthesis was deployed. Because of the risk of complications at smaller aortic sizes in patients with Turner syndrome, it may not be appropriate to determine management of this population using values for the general population [29]. This operation is extremely high risk in any case; however, if dense scarring is noted preoperatively, then surgeon might consider adjunctive maneuvers before performing another sternotomy. Unable to process the form. One benefit of using MRI in young patients is that they generally can suspend respiration for a relatively long scanning time of 25–35 seconds, allowing acquisition of MR images with a spatial resolution approaching that of CT. As mentioned by Apfaltrer et al. In addition, there is a lack of consistency with regard to which measurements to use (inner lumen only vs lumen and wall) and whether measurements should be normalized to age, sex, and body surface area. Reference values are specific to each segment within the aortic root. If aortic arch anatomy is unclear, it is useful to perform nonselective angiography and/or further imaging with CT angiography. Knowledge of abnormal aortic arch anatomy can decrease fluoroscopy time and contrast load administered, thereby reducing potential periprocedural adverse events. A summary of critical aortic measurement thresholds and important associated secondary anatomic considerations is outlined in the following sections. It may be useful to remeasure a previous study in a side-by-side comparison to decrease interobserver variability. Other factors that affect preoperative planning include involvement of the aortic valve or coronary ostia by the aneurysm [44]. A–C, Balanced steady-state free precession scout images obtained before MR angiography show dural ectasia (arrows, A and B) and pectus deformity (arrow, C). an aortic root segmentation illustrating the basic anatomy of a normal aortic valve with three cusps and the ostium of the two coronary arteries. Figure 1: sectional cardiac anatomy (creative commons illustration), Case 1: aortic root dilatation in Marfan syndrome, three aortic valve leaflets and leaflet attachments, right and left contain coronary aorta ostia, with a third non-coronary aortic sinus located posteriorly, three interleaflet trigones: space between the cusps and the annulus, sinotubular junction, which divides the aortic root from the ascending aorta. However, in patients with Marfan syndrome, the aortic valve, aortic sinuses, and ascending aorta are typically replaced with a composite graft [44] and the coronary ostia are reimplanted. Multimodality imaging of diseases of the thoracic aorta in adults: from the American Society of Echocardiography and the European Association of Cardiovascular Imaging: endorsed by the Society of Cardiovascular Computed Tomography and Society for Cardiovascular Magnetic Resonance. The American College of Cardiology and the American Heart Association [17] recommend 6-month follow-up with particular attention to the aortic arch and descending aorta for additional sites of aneurysm formation. In our practice, if the patient is undergoing surgery, surgeons typically remove and reconstruct all aortas greater than 45 mm in diameter through a hemiarch technique, although other practices may be less aggressive. Therefore, surgical repair is recommended at an aortic diameter of 40 mm by transesophageal echocardiography, 45 mm by CT or MRI, or root expansion of more than 5 mm/y [17, 40, 43]. Aortic size indexes of 25 mm/ m2 or greater have the highest risk of dissection [27]. CT was performed to exclude supravalvular pulmonary stenosis in a 23-year-old woman with a right-sided systolic murmur. Fig. Other factors, including cardiac chamber volumes, chest diameter, and body surface area, did not show significant correlation with ascending aortic diameter. Aorta is normal caliber. The use of ECG-gated 3D datasets, with capability for multiplanar reformatting and measurement, and consistent reporting of measurements at anatomic landmarks will improve clinical care and the confidence of referring cardiologists and surgeons. From this image, we can see the various structures that form the aortic valve complex. Recent advances in multi-detector CT image processing software have allowed the creation of virtual endoluminal views of the aortic root and improved assessment of the intramural course (the length and relationship to the intercoronary commissure) of the coronary artery, which is … The sinuses of Valsalva are outward pouches within the aortic root where the coronary arteries arise from. The aortic root is the portion of the aorta beginning at the aortic annulus and extending to the sinotubular junction. The surgical anatomy of the aortic root. OBJECTIVE We provide an outline of aortic anatomy and disease patterns, describe methods of aortic measurement, and highlight measurement thresholds for surgical intervention. For example, measurements made when sizing transcatheter aortic valves using the 2D technique may underestimate the largest annular dimension. This patient does not have known connective tissue disorder, but findings are suggestive of possibility. Echocardiography is the method by which reference values for measurements of the aortic root and ascending aorta have been obtained, and echo-cardiography is widely used for the detection and follow-up of aortic disease. [5] Gotway MB, Dawn SK (2003) Thoracic aorta imaging with multislice CT. Radiol Clin North Am 41: 521-543 (PMID: 12797604) [6] Grollman MB (1989) The aortic diverticulim: a remnant of the partially involuted dorsal aortic root. During sternotomy and mediastinal dissection, patient's aorta ruptured and patient exsanguinated. A presentation from the Computed Tomography ePosters session at ESC CONGRESS 2020 - The Digital Experience In order to bring you the best possible user experience, this site uses Javascript. Isolated Diffuse Ground-Glass Opacity in Thoracic CT: Causes and Clinical Presentations. A and B, Double oblique CT angiographic images obtained from 3D workstation show cross-sectional anatomy of aortic annulus. imaging in - Marfan's disease - Bicuspid aortic valve disease / aneurysm The ascending aorta lies above the sinotubular junction, which forms the boundary between the ascending aorta and the aortic [00:01:00] root. Fig. They often have no symptoms and doctors find them during x-rays or CT scans. Note asymmetric measurements obtained in long and short axes. This finding may lead to consideration of surgical intervention at such a value. There is not widespread consensus regarding repair of these complicated aneurysms. A, Image obtained during systole shows bicuspid valve with fusion of right commissure and left commissure (arrow). The ascending aorta rises to a point above the pulmonary arteries where the aortic arch begins with the innominate artery origin. Fig. Like the pulmonary valve, the aortic valve has three cusps. The internal structure of the aortic root consists of the … In children with Loeys-Dietz syndrome, prophylactic surgery is undertaken when the aortic diameter exceeds the 99th percentile for age and the aortic valve annulus measures 18–20 mm [17]. The aortic root is comprised of three main components: the sinotubular junction, the aortic sinus (containing the sinuses of Valsalva, the leaflets of the aortic valve and the coronet-shaped surgical annulus) and the basal ring (where the aortic root joins the left ventricle). Imaging the heart valves using ECG-gated 64-detector row cardiac CT. Measurements obtained without gating may overestimate aortic diameter and lead to inappropriate referral for surgery (Fig. Compared to MRI, CT can be performed rapidly, is not restricted by routine life support and monitoring equipment, and is not precluded by the presence of implanted electronic or ferromagnetic devices or claustrophobia. There is subtle volume averaging from inferior-most component of three aortic valve cusps (arrows, B). Image was obtained during breath-holding using ECG-gated 3D balanced steady-state free precession technique. We also discuss findings that can assist in preoperative planning and in detecting underlying connective tissue disorders. Screening of family members is important, and in affected family members, aortopathy may be present even in the absence of BAV. OBJECTIVE. The sinuses taper superiorly, where they meet the ascending aorta at the sinotubular junction (or “sinotubular ridge”). Especially designed for and with cardiovascular specialists, 3mensio Structural Heart ™ will let you plan aortic and mitral valve procedures and left atrial appendage closures. 1 Over more than 30 years, CVG has become a low risk and very durable procedure. 13). 9 —71-year-old man referred for preoperative imaging to plan transcatheter aortic valve intervention. This is the sinus of Valsalva. (A) Volume rendered (A) Volume rendered 3-dimension reconstruction showing the 3 Valsalva sinuses and their relationship with the left and right coronary arteries; (B) sagittal oblique Kate Hanneman, Frandics P. Chan, R. Scott Mitchell, D. Craig Miller, Dominik Fleischmann. If an ascending aortic aneurysm extends to involve the aortic arch or descending aorta, a more complicated repair may be necessary and accurate measurements of the arch and descending aorta will facilitate clinical decision making. To the best of our knowledge this is the first time a complete model of the aortic valve (including leaflets) and the ascending aortic root, estimated from CT, has been proposed. C and D, Double oblique cross-sectional images. The RCA ran between the aorta and the pulmonary artery (lower image). Fig. CT Findings of Sigmoid Volvulus, Perspective. Aortic root anatomy . Two-dimensional echo-cardiographic measurements of the aortic root and ascending aorta are usually obtained from the parasternal long-axis view–roughly equivalent to the three-chamber view in cardiac CT or MRI (Fig. Freeman LA, Young PM, Foley TA et-al. Fig. van Rijk-Zwikker. AU - Freeman, Laura A. We provide an outline of aortic anatomy and disease patterns, describe methods of aortic measurement, and highlight measurement thresholds for surgical intervention. The aortic root is the first part of the aorta and connects the heart to the systemic circulation. B, Single frame of streamlines from 4D MR flow acquisition shows high-velocity streamlines impacting site of eccentric dilatation of ascending aorta (arrow). Generating clinically relevant measurements requires high-quality images, a consistent strategy for radiologic aortic evaluation, and an understanding of how those measurements impact clinical decisions. The aortic root is the cylindrical segment of aorta from the ventriculoaortic junction to the sinotubular junction, which contains the aortic valve, the aortic annulus, and the sinuses of Valsalva (see Fig. Of all thoracic aortic aneurysms, 60% involve the aortic root, ascending aorta, or both [3], and there is a cumulative yearly risk of rupture or dissection of up to 6.9% per year with a maximal diameter of larger than 60 mm [4–6]. This discordance indicates a need for more research on correlation of body surface area with aortic size and on the use of sex- and age-adjusted values of aortic diameters in clinical decision making. Aortic Root. Fig. Educational video for medical students and cardiac surgeons about the anatomy of the Aortic valve. Fig. CT and MRI both offer potential for a thorough evaluation of the aorta and precise aortic measurements using 3D datasets. Blood enters the left ventricle via the mitral valve. The importance of these factors is emphasized when consideration is given to the strict surgical criteria for aortic repair. The results of previous small studies have shown that age, sex, and body surface area correlate with aortic size [4, 10]. Double oblique ECG-gated balanced steady-state free precession MR images through aortic sinuses are shown. [8]. The mean age at death of those with vascular involvement is 26 years, necessitating earlier, more aggressive management in this population [17, 21]. Exposure may be affected by prior trauma or surgery to the chest wall with associated scarring or deformity. In this article, we will outline aortic anatomy and disease patterns, show methods of aortic measurement, and highlight measurement thresholds for surgical intervention.