AJR 2001; 177:689-691
© American Roentgen Ray Society
Giant Right Coronary Aneurysm
CT Angiographic and Echocardiographic Findings
Eli Konen1,
Micha S. Feinberg2,
Binyamina Morag1,
Victor Guetta2,
Ami Shinfeld3,
Aram Smolinsky3 and
Judith Rozenman1
1
Department of Diagnostic Imaging, Chaim Sheba Medical Center, Tel Hashomer
52621, Israel, and the Sackler School of Medicine, Tel-Aviv University,
Israel.
2
Heart Institute, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel, and
the Sackler School of Medicine, Tel-Aviv University, Israel.
3
Department of Cardiac Surgery, Chaim Sheba Medical Center, Tel Hashomer 52621,
Israel, and the Sackler School of Medicine, Tel-Aviv University, Israel.
Received December 7, 2000;
accepted after revision March 8, 2001.
Address correspondence to E. Konen.
Introduction
Small coronary artery aneurysms have been observed in up to 5% of patients
undergoing coronary angiography
[1]. Huge aneurysms, causing a
pronounced bulge of the heart contour, are rare and may simulate a mediastinal
mass [2,
3]. We report the findings of
CT angiography and color Doppler echocardiography in a patient with a right
coronary artery aneurysm 10 cm in diameter.
Case Report
A 54-year-old man was referred to our department for a CT-guided
transthoracic biopsy of an anterior mediastinal mass. The patient was a heavy
cigarette smoker with a 10-year history of systemic hypertension and mild
diabetes mellitus. He experienced a single episode of syncope and gradually
increasing fatigue during a 6-month period before admission. Ambulatory
imaging performed before admission included posteroanterior chest radiography
(Fig. 1A) that showed an
abnormal contour of the right heart border. A single-bolus contrast-enhanced
CT scan revealed a large inhomogeneous enhancing anterior mediastinal mass
with peripheral calcifications. On admission, the patient's heart rate was
regular at 90/min, and his peripheral arterial blood pressure was 150 over 100
mm Hg. Precordial auscultation disclosed no abnormalities.
A CT angiogram was obtained using the following three-phase scanning
protocol: unenhanced phase, arterial phase, and equilibrium phase. Contrast
material, ioxitalamate 380 mg/mL (Telebrix 38; Laboratoire Guerbet,
Aulnay-sous-Bois, France), was administered into an antecubital fossa vein by
an automatic power injector at a rate of 4 mL/sec. The CT examination was
performed on a double-detector helical CT Twin RTS scanner (Elscint, Haifa,
Israel) using a dual pitch of 2. Effective slice thickness was 3.2 mm with a
2-mm increment. Computerized reformations were performed on an independent
image processing workstation (Provision; Algotec, Raanana, Israel). An
unenhanced phase scan showed a 101 x 99 mm rounded homogeneous
retrosternal mass inside the pericardium, compressing the right atrium and
displacing the heart to the left (Fig.
1B). The density of the mass was similar to that of the heart
chambers, and small linear calcifications were seen at its periphery. An
arterial phase scan revealed an inhomogeneous circumferential enhancement
suggesting a whirling stream of contrast medium inside the mass
(Fig. 1C). An equilibrium phase
scan obtained 4 min after injection again showed the mass to be homogeneous,
with the same degree of enhancement as the heart chambers
(Fig. 1D). A shaded-surface
display clearly delineated the relation between the mass and the ascending
aorta and main pulmonary artery and enabled us to estimate its volume at 414
± 20 cm3. Although CT angiographic findings and the location
of the mass were highly suggestive of a right coronary artery aneurysm,
neither the right coronary artery nor the neck of the aneurysm could be
recognized.
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Fig. 1B —54-year-old man with giant right coronary aneurysm.
Unenhanced axial CT scan shows rounded 10-cm-diameter anterior soft-tissue
mediastinal mass compressing heart to left side. Note similar density of heart
chambers and small peripheral linear calcifications (arrowheads).
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Fig. 1C —54-year-old man with giant right coronary aneurysm. CT axial
angiogram at arterial phase shows inhomogeneous circumferential enhancement,
suggesting turbulent stream of contrast material inside mass.
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Fig. 1D —54-year-old man with giant right coronary aneurysm. CT axial
angiogram obtained 4 min after injection also shows mass to be homogeneous,
with similar degree of enhancement as heart chambers.
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Transthoracic echocardiography revealed a large cystic cavity anterior and
lateral to the cardiac chambers, compressing the right atrium and right
ventricle. Color-flow Doppler imaging showed a jet eccentrically directed from
the ostium of the right coronary artery to the large cavity. A spectral
Doppler velocity imaging pattern was consistent with a continuous gradient
(systolic and diastolic) between the aorta and the cavity, with a peak
velocity of about 4 m/sec. Transesophageal imaging confirmed these findings
(Fig. 1E), and no connection
was shown between the cavity and the pulmonary artery.
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Fig. 1E —54-year-old man with giant right coronary aneurysm.
Transesophageal color Doppler echocardiogram shows jet directed from right
coronary ostium (arrow) impinging large cystic cavity (AN). AO =
aorta, LA = left atrium, LV = left ventricle.
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Cardiac catheterization was performed from the right femoral artery. The
proximal right coronary artery opened into a large spherical cavity that
filled with contrast medium in a swirling fashion with slow opacification and
without a shunt or fistula (Fig.
1F). The left coronary system had no significant stenosis. The
circumflex artery appeared to be ectatic, with dilatation of 6 mm in diameter
at the distal portion.
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Fig. 1F —54-year-old man with giant right coronary aneurysm. Right
coronary angiogram in left anterior—oblique view shows proximal right
coronary artery opening into large spherical aneurysm cavity.
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At surgery, a large thin-walled spherical mass was found between the
sternum and the aortic root, with the right coronary artery feeding the mass
(Fig. 1G). The aneurysm was
incised, and the patient's postoperative recovery was uneventful.
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Fig. 1G —54-year-old man with giant right coronary aneurysm.
Photograph of operative view through mid sternotomy shows 10-cm round aneurysm
(asterisks) located between sternum and aortic root. Feeding site was
right coronary ostium.
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Discussion
Although small coronary artery aneurysms are not a rare finding on coronary
angiography [1], few reports
exist in the literature that focus on the findings of giant coronary artery
aneurysms
[2,3,4,5].
The main causes for coronary artery aneurysms in the Western world are
atherosclerosis, congenital origin, and mycotic—embolic disease
[6]. Most atheromatous
aneurysms are small and thick-walled and have a low risk of spontaneous
rupture [1]. Congenital
aneurysms, which are usually situated on the right coronary artery, are
generally large and are most commonly found in young patients. Congenital
aneurysms have been reported to rupture into the pericardial space, causing
cardiac tamponade [7], or into
the right atrium [3]. Although
giant coronary aneurysms are usually congenital in origin, the relatively
advanced age of our patient and his multiple risk factors suggested
atherosclerosis as the most probable cause of the aneurysm.
The differential diagnosis of a giant coronary aneurysm includes aneurysm
of the heart wall, posttraumatic pseudoaneurysm of the ascending aorta or the
pulmonary trunk, tumor of the heart or pericardium, and thymoma
[5]. When contrast material is
injected, the turbulence of enhanced blood in such a large aneurysm may
simulate an inhomogeneous enhancing mass. The small peripheral linear
calcifications and the typical location of the mass in our patient suggested a
coronary aneurysm. Three-phase CT angiography was helpful in confirming our
suspicion by showing homogeneous and similar densities of the mass and cardiac
chambers in the unenhanced (first) and equilibrium (third) phases, and
turbulence-like enhancement in the arterial (second) phase. Radiologists
should be familiar with these CT angiographic characteristics, because a false
interpretation of a soft-tissue mediastinal mass may result in a biopsy with a
possible fatal outcome.
CT angiography also enables the generation of two- and three-dimensional
reformations. In our patient, shaded-surface display was found to be helpful
to the cardiac surgeons in preoperative planning by clearly showing the
spatial relations between the huge aneurysm, the great vessels, and the heart,
and by emphasizing the close proximity of the aneurysm to the sternum. CT
angiography also enabled diameter measurements of the aneurysm in any
desirable plane and provided a computerized estimate of its volume.
MR imaging has been shown to be useful in the diagnosis of giant coronary
aneurysm [2], with the
advantage over CT of not using ionizing radiation. Nevertheless, CT
angiography is faster, cheaper, and more available in many medical centers
than MR imaging. Additionally, MR imaging cannot show the typical linear
peripheral calcifications of the aneurysm, which is important for a correct
diagnosis.
References
-
Swaye PS, Lloyd DF, Litwin P, et al. Aneurysmal coronary artery
disease. Circulation
1983;67:134
-138[Abstract/Free Full Text]
-
Channon KM, Wadsworth S, Bashir Y. Giant coronary artery aneurysm
presenting as a mediastinal mass. Am J Cardiol
1998;82:1307
-1308[Medline]
-
Abou Eid G, Lang-Lazdunski L, Hvass U, et al. Management of giant
coronary artery aneurysm with fistulization into the right atrium.
Ann Thorac Surg
1993;56:372
-374[Abstract]
-
Selke KG, Vemulapalli P, Brodarick SA, et al. Giant coronary artery
aneurysm: detection with echocardiography, computed tomography, and magnetic
resonance imaging. Am Heart J
1991;121:1544
-1547[Medline]
-
Hinterauer L, Roelli H, Goebel N, Steinbrunn W, Senning A. Huge
left coronary artery aneurysm associated with multiple arterial aneurysms.
Cardiovasc Intervent Radiol
1985;8:127
-130[Medline]
-
Daoud AS, Pankin D, Tulgan H, Florentin RA. Aneurysms of the
coronary artery; report of ten cases and review of literature. Am J
Cardiol 1963;11:228
-237[Medline]
-
Wan S, LeClerc JL, Vachiery JL, Vincent JL. Cardiac tamponade due
to spontaneous rupture of right coronary artery aneurysm. Ann
Thorac Surg 1996;62:575
-576[Abstract/Free Full Text]
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Introduction
Case Report
