Advertisement

Diameters of the thoracic aorta throughout life as measured with helical computed tomography

      Abstract

      Objective: The use of helical computed tomography is well established in the evaluation of the thoracic aorta. Nevertheless, normal diameters and their changes during adult life according to this method are not available. We planned to set up normal diameters for the thoracic aorta of adults obtained by helical computed tomography. Methods: Seventy adults, 17 to 89 years old, without any signs of cardiovascular disease were investigated with helical computed tomography. Aortic diameters were measured at seven predefined thoracic levels. Results: Aortic diameters (mean ± SD) were 2.98 ± 0.46 cm at the aortic valve sinus, 3.09 ± 0.41 cm at the ascending aorta, 2.94 ± 0.42 cm proximal to the innominate artery, 2.77 ± 0.37 cm at the proximal transverse arch, 2.61 ± 0.41 cm at the distal transverse arch, 2.47 ± 0.40 cm at the isthmus, and 2.43 ± 0.35 cm at the diaphragm. Men had slightly longer diameters than did women. All diameters increased with age. There was no influence of weight, height, or body surface area. After normalization to the diameter at diaphragmatic level, no statistically significantly influential factor could be detected. Conclusions: This study delineates normal intrathoracic aortic diameters for helical computed tomography, including relationships with sex and age. Pathologic dimensions of the aorta should preferably be provided as percentiles or z scores.
      J Thorac Cardiovasc Surg 2002;123:1060-6
      After the introduction of helical computed tomography (CT) in the late 1980s, imaging of the aorta soon became a routine procedure for evaluation of the aorta in patients with aortic dissection, stenosis, or aneurysm formation.
      • Trerotola SO
      Can helical CT replace aortography in thoracic trauma?.
      • Sommer T
      • Fehske W
      • Holzknecht N
      • Smekal AV
      • Keller E
      • Lutterbey G
      • et al.
      Aortic dissection: a comparative study of diagnosis with spiral CT, multiplanar transesophageal echocardiography, and MR imaging.
      Furthermore, such imaging has increasingly been used for the assessment of aortic involvement in adult patients with connective tissue disease or congenital aortic diseases such as coarctation
      • Kaemmerer H
      • Mugge A
      • Oelert F
      • Prokop M
      • Rapp U
      • Schoehl W
      • et al.
      [Evaluation of the aorta and supra-aortic vessels with spiral CT and 3-dimensional vascular reconstruction after operation of aortic isthmus stenosis].
      • Park JH
      • Chung JW
      • Im JG
      • Kim SK
      • Park YB
      • Han MC
      Takayasu arteritis: evaluation of mural changes in the aorta and pulmonary artery with CT angiography.
      • Chung JW
      • Park JH
      • Im JG
      • Chung MJ
      • Han MC
      • Ahn H
      Spiral CT angiography of the thoracic aorta.
      • Hopkins KL
      • Patrick LE
      • Simoneaux SF
      • Bank ER
      • Parks WJ
      • Smith SS
      Pediatric great vessel anomalies: initial clinical experience with spiral CT angiography.
      • Becker C
      • Soppa C
      • Fink U
      • Haubner M
      • Muller-Lisse U
      • Englmeier KH
      • et al.
      Spiral CT angiography and 3D reconstruction in patients with aortic coarctation.
      • Yamada I
      • Nakagawa T
      • Himeno Y
      • Numano F
      • Shibuya H
      Takayasu arteritis: evaluation of the thoracic aorta with CT angiography.
      to quantify an additional hypoplastic aortic arch or a dilated ascending aorta. However, there are no reference data regarding thoracic aortic diameters according to helical CT to help characterize the physiologic range of aortic dimensions. This is regrettable, because the development of new imaging modalities makes setting up reference data essential, and helical CT provides excellent accuracy and reproducibility.
      In the absence of reference data, it has often been suggested that diameter ratios normalized to those of the ascending aorta or the descending aorta at the diaphragmatic level be used for the definition of aortic stenosis or dilatation.
      • Kaemmerer H
      • Mugge A
      • Oelert F
      • Prokop M
      • Rapp U
      • Schoehl W
      • et al.
      [Evaluation of the aorta and supra-aortic vessels with spiral CT and 3-dimensional vascular reconstruction after operation of aortic isthmus stenosis].
      • Moulaert AJ
      • Bruins CC
      • Oppenheimer-Dekker A
      Anomalies of the aortic arch and ventricular septal defects.
      This strategy is subject to discussion, however, because the aorta may show pathologic diameters at the chosen reference levels and because these ratios vary with age, even in adults.
      • Clarkson PM
      • Brandt PW
      Aortic diameters in infants and young children: normative angiographic data.
      • Aronberg DJ
      • Glazer HS
      • Madsen K
      • Sagel SS
      Normal thoracic aortic diameters by computed tomography.
      This study was designed to define reference values obtained by helical CT for the normal thoracic aorta in adults and to analyze their relationship with sex, age, weight, height, and body surface area.

      Material and methods

      Patients

      Table 1Demographic data of patients
      FemaleMaleTotal
      No.244670
      Age (y)
       Mean ± SD49.6 ± 19.150.5 ± 15.250.2 ± 16.5
       Range17-8919-7717-89
      Weight (kg)
       Mean ± SD64.3 ± 14.977.6 ± 14.273.1 ± 15.7
       Range41-10446-10641-106
      Height (cm)
       Mean ± SD165.9 ± 6.6175.8 ± 7.3172.4 ± 8.2
       Range150-179159-199150-199
      Body surface area (m2)
       Mean ± SD1.70 ± 0.191.93 ± 0.191.85 ± 0.22
       Range1.33-2.151.62-2.431.33-2.43

      Measurements

      Figure thumbnail gr1
      Fig. 1Levels of measured aortic diameters: 1, Aortic valve sinus; 2, ascending aorta; 3, aorta proximal to innominate artery; 4, proximal transverse aortic arch; 5, distal transverse aortic arch; 6, aortic isthmus; 7, descending aorta at level of diaphragmatic wall of left ventricle.

      Image acquisition

      Helical CT scans were performed on a Somatom Plus (Siemens AG, Medical Engineering, Forchheim, Germany). Contrast scans were acquired after an antecubital intravenous injection of 80 to 100 mL of a nonionic contrast medium (Ultravist 300; Schering AG, Berlin, Germany) containing 300-mg/mL iodine. The injection rate was 1.5 to 3 mL/s. The helical CT scan was performed with a delay of 20 to 25 seconds after starting the injection.
      The scan of the entire thorax was performed during a single held breath. The tube detector unit was rotating continuously at 1 to 1.3 rotations per second. Slice collimation was 5 mm, table speed was 8 to 10 mm/s in the caudocranial direction, and total scanning time was 25 to 30 seconds for the total longitudinal coverage from the sinus up to the apex of the pleural cavity.

      Image analysis

      Reconstruction was achieved every 4 mm with the 180° linear interpolation algorithm. Multiplanar reconstruction was generated on a Magic View workstation (Siemens Medical Systems, Erlangen, Germany). The slices were manually adjusted for each aortic level to get an oblique plane strictly perpendicular to the course of the aorta. The internal diameter of the vessel was measured with an electronic caliper in three different directions. The arithmetic mean of those three estimates was used for further calculations. All images were reconstructed and analyzed by an experienced observer (U.R.-B., S.B., T.B.).

      Statistical analysis

      Measurements were stored in a database and exported to a statistical software package (StatView; SAS Institute, Inc, Cary, NC; SPSS; SPSS Inc, Chicago, Ill) for analysis. Normal distribution of the diameters was assumed. To analyze the changes of the diameters along the course of the aorta, paired t tests of neighboring diameters were used. Analysis of variance was performed to test for the influences on the aortic diameters of sex, age, weight, height, and body surface area. Variables that showed an influence were analyzed in detail with 2-sided t tests, additional analyses of variance, or multiple regression analysis.

      Results

      Figure thumbnail gr2
      Fig. 2Mean aortic diameters at various levels measured by helical CT in 70 adults. Thin lines represent ± 2 SD, representing 95% reference area.
      Table 2Aortic diameters at various thoracic levels in adults measured with helical CT
      Aortic levelFemale (n = 24)Male (n = 46)Total (n = 70)P value
      Aortic valve sinus2.88 ± 0.383.04 ± 0.502.98 ± 0.46.196
      Ascending aorta (maximum)2.90 ± 0.343.20 ± 0.423.09 ± 0.41.004
      Proximal to innominate artery2.82 ± 0.363.00 ± 0.442.94 ± 0.42.095
      Proximal transverse arch2.65 ± 0.272.84 ± 0.402.77 ± 0.37.044
      Distal transverse arch2.40 ± 0.292.72 ± 0.432.61 ± 0.41.001
      Aortic isthmus2.32 ± 0.362.55 ± 0.392.47 ± 0.40.016
      Diaphragm2.27 ± 0.312.51 ± 0.342.43 ± 0.35.005
      Measurements are expressed as mean ± SD in centimeters.
      Table 3Regression analysis of the influence of age on aortic diameters at various thoracic levels in 70 adults measured with helical CT
      Aortic levelSlope (cm/y)Intercept (cm)rr2P value
      Aortic valve sinus0.01242.360.4430.196<.001
      Ascending aorta (maximum)0.01532.320.6120.375<.001
      Proximal to innominate artery0.01362.260.5360.287<.001
      Proximal transverse arch0.01172.190.5240.274<.001
      Distal transverse arch0.01182.020.4740.224<.001
      Aortic isthmus0.00782.080.3270.106.006
      Diaphragm0.01241.800.5900.348<.001
      Slope describes the increase during adulthood.
      Figure thumbnail gr3
      Fig. 3Age-related means and 95% reference bands of internal diameter (in centimeters) of thoracic aorta at various levels, derived from helical CT measurements in 70 adults 17-89 years old. Open circles represent women; closed circles represent men.
      Figure thumbnail gr4
      Fig. 4Mean ratios of aortic diameters at various levels normalized to diameter at diaphragm as measured by helical CT in 70 adults. Thin lines represent ± 2 SD, representing 95% reference area.

      Discussion

      The aorta is a complex vascular structure with many different functions varying along its course. The thoracic aorta provides compliance with elastic recoil to maintain blood pressure and antegrade blood flow throughout diastole. The more distal abdominal aorta functions mainly as a conduit. The varying functions are reflected in the histologic structure of the aorta. The elastin/collagen ratio is highest in the thoracic part and decreases distally. With age, the aortic wall structure changes. Elastin fragmentation, fibrosis, and media necrosis occur in the aorta as signs of aging.
      • Schlatmann TJ
      • Becker AE
      Histologic changes in the normal aging aorta: implications for dissecting aortic aneurysm.
      Furthermore, various diseases alter aortic structure and function
      • Stefanadis C
      • Stratos C
      • Vlachopoulos C
      • Marakas S
      • Boudoulas H
      • Kallikazaros I
      • et al.
      Pressure-diameter relation of the human aorta: a new method of determination by the application of a special ultrasonic dimension catheter.
      • Stefanadis C
      • Dernellis J
      • Vlachopoulos C
      • Tsioufis C
      • Tsiamis E
      • Toutouzas K
      • et al.
      Aortic function in arterial hypertension determined by pressure-diameter relation: effects of diltiazem.
      • Stefanadis C
      • Dernellis J
      • Tsiamis E
      • et al.
      Aortic stiffness as a risk factor for recurrent acute coronary events in patients with ischaemic heart disease.
      and may cause obstruction or dilatation of the aorta. Both obstruction and dilatation may be circumscript, segmental, or spread throughout the entire aorta.
      Different methods have been used to assess and follow up such structural changes. Management decisions often depend strongly on the comparison of measured aortic diameters with normal values. Especially for the definition and classification of structural abnormalities, such as aneurysm, aortomegaly, ectasia, stenosis, coarctation, and hypoplasia, the knowledge of normal aortic diameters at different levels is essential. Reference values have to be built up for each method.
      • Johnston KW
      • Rutherford RB
      • Tilson MD
      • Shah DM
      • Hollier L
      • Stanley JC
      Suggested standards for reporting on arterial aneurysms.
      With a standard method such as helical CT, one should not use normal values obtained from such other techniques as echocardiography, magnetic resonance imaging, angiography, or even postmortem studies, although differences in measurement should be small and confined to fundamental differences in image analysis or acquisition. We therefore present nomograms for aortic dimensions at various intrathoracic levels in healthy adults according to helical CT data (Figure 2).
      Comparison of the presented helical CT data with data from such other imaging methods as echocardiography, angiography, conventional axial CT, and magnetic resonance imaging is difficult, because these data are sparse and sometimes only focus on specific segments of the aorta.
      Transthoracic echocardiography in adults is mostly restricted to the aortic root for technical reasons. Reference values exist only for children and young adults.
      • Snider AR
      • Enderlein MA
      • Teitel DF
      • Juster RP
      Two-dimensional echocardiographic determination of aortic and pulmonary artery sizes from infancy to adulthood in normal subjects.
      • Reed CM
      • Richey PA
      • Pulliam DA
      • Somes GW
      • Alpert BS
      Aortic dimensions in tall men and women.
      • Roman MJ
      • Devereux RB
      • Kramer-Fox R
      • O'Loughlin J
      Two-dimensional echocardiographic aortic root dimensions in normal children and adults.
      • Rozendaal L
      • Groenink M
      • Naeff MS
      • Hennekam RC
      • Hart AA
      • van der Wall EE
      • et al.
      Marfan syndrome in children and adolescents: an adjusted nomogram for screening aortic root dilatation.
      Reported aortic diameters of adolescents are smaller than those presented in our study. This difference could be due to the younger age of the investigated population.
      Transesophageal echocardiography is the method of choice to visualize the ascending and descending thoracic aorta in patients with aortic dissection or after thoracic trauma,
      • Sommer T
      • Fehske W
      • Holzknecht N
      • Smekal AV
      • Keller E
      • Lutterbey G
      • et al.
      Aortic dissection: a comparative study of diagnosis with spiral CT, multiplanar transesophageal echocardiography, and MR imaging.
      whereas the transesophageal assessment of the aortic arch is limited. Nevertheless, comprehensive transesophageal echocardiographic data regarding the size of the normal thoracic aorta are still lacking.
      In some institutions angiography is still considered the criterion standard for visualization of the aorta. Although Clarkson and associates
      • Clarkson PM
      • Brandt PW
      Aortic diameters in infants and young children: normative angiographic data.
      set up normal values for all levels of the intrathoracic aorta in children 6 years and younger, normal angiographic values for adults are still absent.
      For years, conventional axial CT was also used to visualize the thoracic aorta. Because only axial planes are available, however, the diameter of the aortic arch and sometimes that of the ascending aorta are difficult to measure correctly. Therefore only reference diameters for the ascending and descending aorta exist.
      • Aronberg DJ
      • Glazer HS
      • Madsen K
      • Sagel SS
      Normal thoracic aortic diameters by computed tomography.
      The published values for the ascending and more cranial descending aorta are higher than in our series, with only the values at the diaphragmatic level similar to our results. This overestimates the ascending aorta by as much as 6 mm, or 21%. The reason is probably that measurements were only taken in the axial plane, not strictly perpendicular to the aortic wall.
      In the last years magnetic resonance imaging has been used increasingly for the follow-up of patients with chronic aortic disease.
      • Simpson IA
      • Chung KJ
      • Glass RF
      • Sahn DJ
      • Sherman FS
      • Hesselink J
      Cine magnetic resonance imaging for evaluation of anatomy and flow relations in infants and children with coarctation of the aorta.
      • Kaemmerer H
      • Ehrenheim C
      • Wilken W
      • Burchert W
      • Luhmer I
      • Hundeshagen H
      • et al.
      Klinische und kernspintomographische Verlaufskontrollen bei Kindern nach Dilatation einer Aortenisthmusstenose (CoA).
      • Kaemmerer H
      • Mugge A
      • Prokop M
      • Schirg E
      • Oelert F
      • Bahlmann J
      • et al.
      [Diagnostic imaging in follow-up of surgically treated stenosis of the aortic isthmus in adolescents and adults].
      However, no normal values for aortic dimensions in adults are available for this method either.
      In this study we showed that in adults aortic diameters vary with age and sex but are independent of weight, height, and body surface area. Sex has only a weak influence, with mean values for women and men differing no more than 3.2 mm at any level, which is minimal compared to normal variation (within 1 SD).
      Concerning the influence of age, this study confirms data available from conventional CT. This study matches with the study of Aronberg and associates,
      • Aronberg DJ
      • Glazer HS
      • Madsen K
      • Sagel SS
      Normal thoracic aortic diameters by computed tomography.
      which showed that aortic diameters increase about 1 mm per decade during adulthood. For the abdominal aorta, Pearce and colleagues
      • Pearce WH
      • Slaughter MS
      • LeMaire S
      • Salyapongse AN
      • Feinglass J
      • McCarthy WJ
      • et al.
      Aortic diameter as a function of age, gender, and body surface area.
      discussed a multifactorial pathophysiologic picture. The most important factors are plaque formation and elastin fragmentation by elastolytic enzymes without elastin formation, which ceases after the first few years of life. For the increasing diameters in the thoracic aorta, the elastic components might be more pronounced than in the abdominal aorta.
      Any influence of anthropometric data on aortic diameters was not apparent in this series. This is consistent with other studies, which similarly did not show any influence of height, weight, or body surface area on aortic dimensions in adults when these data were adjusted for age and sex.
      • Aronberg DJ
      • Glazer HS
      • Madsen K
      • Sagel SS
      Normal thoracic aortic diameters by computed tomography.
      • Reed CM
      • Richey PA
      • Pulliam DA
      • Somes GW
      • Alpert BS
      Aortic dimensions in tall men and women.
      Only studies that included children used diameters adjusted for body surface area, never proving whether that is appropriate in adults.
      In view of the lack of normal values, it has been suggested that the ratio of a given aortic diameter to that at a reference level be used to define stenosis or dilatation.
      • Moulaert AJ
      • Bruins CC
      • Oppenheimer-Dekker A
      Anomalies of the aortic arch and ventricular septal defects.
      Either the ascending aorta or the aorta at diaphragmatic level was selected as the reference level. This is questionable, however, because the aortic root is often subject to pathologic changes, not only in patients with connective tissue disease but even in patients with bicuspid aortic valve,
      • Nistri S
      • Sorbo MD
      • Marin M
      • Palisi M
      • Thiene G
      Aortic root dilatation in young men with normally functioning bicuspid aortic valves.
      aortic stenosis, or atherosclerosis. In our opinion, it is therefore more appropriate to choose the diaphragmatic level as the reference level, because aneurysms and hypoplasia are rarely found there. Figure 4 shows those ratios that are independent of age, sex, weight, height, and body surface area in our adult study population. Therefore this approach seems to be ideal as long as the aorta at the diaphragmatic level is free of pathologic changes.
      On the basis of these data, stenosis and dilatation of longer aortic segments, such as vessel hypoplasia, strictures, and aortomegaly, should be defined as a deviation of more than 2 SD from the normal value. Localized aneurysm should continue to be defined as a greater than 50% difference from the diameter of the adhering normal vessel,
      • Johnston KW
      • Rutherford RB
      • Tilson MD
      • Shah DM
      • Hollier L
      • Stanley JC
      Suggested standards for reporting on arterial aneurysms.
      and discrete stenosis such as coarctation should be defined as a greater than 60% reduction in the diameter that Clatworthy and colleagues
      • Clatworthy HW
      • Sako Y
      • Chisholm TC
      Thoracic aortic coarctation: Its experimental production in dogs, with special reference to technical methods capable of inducing significant intraluminal stenosis.
      demonstrated to be hemodynamically significant.

      References

        • Trerotola SO
        Can helical CT replace aortography in thoracic trauma?.
        Radiology. 1995; 197 ([editorial]): 13-15
        • Sommer T
        • Fehske W
        • Holzknecht N
        • Smekal AV
        • Keller E
        • Lutterbey G
        • et al.
        Aortic dissection: a comparative study of diagnosis with spiral CT, multiplanar transesophageal echocardiography, and MR imaging.
        Radiology. 1996; 199: 347-352
        • Kaemmerer H
        • Mugge A
        • Oelert F
        • Prokop M
        • Rapp U
        • Schoehl W
        • et al.
        [Evaluation of the aorta and supra-aortic vessels with spiral CT and 3-dimensional vascular reconstruction after operation of aortic isthmus stenosis].
        Z Kardiol. 1994; 83: 775-783
        • Park JH
        • Chung JW
        • Im JG
        • Kim SK
        • Park YB
        • Han MC
        Takayasu arteritis: evaluation of mural changes in the aorta and pulmonary artery with CT angiography.
        Radiology. 1995; 196: 89-93
        • Chung JW
        • Park JH
        • Im JG
        • Chung MJ
        • Han MC
        • Ahn H
        Spiral CT angiography of the thoracic aorta.
        Radiographics. 1996; 16: 811-824
        • Hopkins KL
        • Patrick LE
        • Simoneaux SF
        • Bank ER
        • Parks WJ
        • Smith SS
        Pediatric great vessel anomalies: initial clinical experience with spiral CT angiography.
        Radiology. 1996; 200: 811-815
        • Becker C
        • Soppa C
        • Fink U
        • Haubner M
        • Muller-Lisse U
        • Englmeier KH
        • et al.
        Spiral CT angiography and 3D reconstruction in patients with aortic coarctation.
        Eur Radiol. 1997; 7: 1473-1477
        • Yamada I
        • Nakagawa T
        • Himeno Y
        • Numano F
        • Shibuya H
        Takayasu arteritis: evaluation of the thoracic aorta with CT angiography.
        Radiology. 1998; 209: 103-109
        • Moulaert AJ
        • Bruins CC
        • Oppenheimer-Dekker A
        Anomalies of the aortic arch and ventricular septal defects.
        Circulation. 1976; 53: 1011-1015
        • Clarkson PM
        • Brandt PW
        Aortic diameters in infants and young children: normative angiographic data.
        Pediatr Cardiol. 1985; 6: 3-6
        • Aronberg DJ
        • Glazer HS
        • Madsen K
        • Sagel SS
        Normal thoracic aortic diameters by computed tomography.
        J Comput Assist Tomogr. 1984; 8: 247-250
        • Schlatmann TJ
        • Becker AE
        Histologic changes in the normal aging aorta: implications for dissecting aortic aneurysm.
        Am J Cardiol. 1977; 39: 13-20
        • Stefanadis C
        • Stratos C
        • Vlachopoulos C
        • Marakas S
        • Boudoulas H
        • Kallikazaros I
        • et al.
        Pressure-diameter relation of the human aorta: a new method of determination by the application of a special ultrasonic dimension catheter.
        Circulation. 1995; 92: 2210-2219
        • Stefanadis C
        • Dernellis J
        • Vlachopoulos C
        • Tsioufis C
        • Tsiamis E
        • Toutouzas K
        • et al.
        Aortic function in arterial hypertension determined by pressure-diameter relation: effects of diltiazem.
        Circulation. 1997; 96: 1853-1858
        • Stefanadis C
        • Dernellis J
        • Tsiamis E
        • et al.
        Aortic stiffness as a risk factor for recurrent acute coronary events in patients with ischaemic heart disease.
        Eur Heart J. 2000; 21: 390-396
        • Johnston KW
        • Rutherford RB
        • Tilson MD
        • Shah DM
        • Hollier L
        • Stanley JC
        Suggested standards for reporting on arterial aneurysms.
        J Vasc Surg. 1991; 13 (Subcommittee on Reporting Standards for Arterial Aneurysms, Ad Hoc Committee on Reporting Standards, Society for Vascular Surgery and North American Chapter, International Society for Cardiovascular Surgery): 452-458
        • Snider AR
        • Enderlein MA
        • Teitel DF
        • Juster RP
        Two-dimensional echocardiographic determination of aortic and pulmonary artery sizes from infancy to adulthood in normal subjects.
        Am J Cardiol. 1984; 53: 218-224
        • Reed CM
        • Richey PA
        • Pulliam DA
        • Somes GW
        • Alpert BS
        Aortic dimensions in tall men and women.
        Am J Cardiol. 1993; 71: 608-610
        • Roman MJ
        • Devereux RB
        • Kramer-Fox R
        • O'Loughlin J
        Two-dimensional echocardiographic aortic root dimensions in normal children and adults.
        Am J Cardiol. 1989; 64: 507-512
        • Rozendaal L
        • Groenink M
        • Naeff MS
        • Hennekam RC
        • Hart AA
        • van der Wall EE
        • et al.
        Marfan syndrome in children and adolescents: an adjusted nomogram for screening aortic root dilatation.
        Heart. 1998; 79: 69-72
        • Simpson IA
        • Chung KJ
        • Glass RF
        • Sahn DJ
        • Sherman FS
        • Hesselink J
        Cine magnetic resonance imaging for evaluation of anatomy and flow relations in infants and children with coarctation of the aorta.
        Circulation. 1988; 78: 142-148
        • Kaemmerer H
        • Ehrenheim C
        • Wilken W
        • Burchert W
        • Luhmer I
        • Hundeshagen H
        • et al.
        Klinische und kernspintomographische Verlaufskontrollen bei Kindern nach Dilatation einer Aortenisthmusstenose (CoA).
        Z Kardiol. 1990; 79: 766-773
        • Kaemmerer H
        • Mugge A
        • Prokop M
        • Schirg E
        • Oelert F
        • Bahlmann J
        • et al.
        [Diagnostic imaging in follow-up of surgically treated stenosis of the aortic isthmus in adolescents and adults].
        Wien Med Wochenschr. 1995; 145: 206-210
        • Pearce WH
        • Slaughter MS
        • LeMaire S
        • Salyapongse AN
        • Feinglass J
        • McCarthy WJ
        • et al.
        Aortic diameter as a function of age, gender, and body surface area.
        Surgery. 1993; 114: 691-697
        • Nistri S
        • Sorbo MD
        • Marin M
        • Palisi M
        • Thiene G
        Aortic root dilatation in young men with normally functioning bicuspid aortic valves.
        Heart. 1999; 82: 19-22
        • Clatworthy HW
        • Sako Y
        • Chisholm TC
        Thoracic aortic coarctation: Its experimental production in dogs, with special reference to technical methods capable of inducing significant intraluminal stenosis.
        Surgery. 1950; 28: 245-273