DOI: 10.1148/rg.243035096
RadioGraphics 2004;24:773-786
© RSNA, 2004
Gadolinium-enhanced Three-dimensional MR Angiography of Takayasu Arteritis1
Marcio V. Nastri, MD,
Luciana P. S. Baptista, MD,
Ronaldo H. Baroni, MD,
Roberto Blasbalg, MD,
Luis F. de Ávila, MD,
Claudia C. Leite, MD,
Claudio C. de Castro, MD and
Giovanni G. Cerri, MD
1 From the Institute of Radiology (M.V.N., R.H.B., R.B., C.C.L., G.G.C.) and Heart Institute (L.P.S.B., L.F.d.A., C.C.d.C.), University of São Paulo Medical School, São Paulo, Brazil. Recipient of an Excellence in Design award at the 2002 RSNA scientific assembly. Received April 7, 2003; revision requested June 8 and received January 28, 2004; accepted February 4. All authors have no financial relationships to disclose. Address correspondence to M.V.N., Rua Itambe 289, ap 507, 01239-001 São Paulo, SP, Brazil (e-mail: marcionastri@yahoo.com).
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Abstract
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Takayasu arteritis is a form of large vessel vasculitis with a possible autoimmune origin that may cause stenosis of the aorta and its major branches. Six types of Takayasu arteritis are recognized; the type depends on whether the ascending aorta, descending thoracic aorta, abdominal aorta, aortic cervicobrachial branches, or renal arteries are affected. The coronary and pulmonary arteries are also sometimes involved. Clinical features of the disease include diminished or absent pulses, claudication, hypertension, and mesenteric angina. Conventional angiography has been the standard imaging tool for diagnosis and evaluation of Takayasu arteritis, although it demonstrates only the lumen of the vessel. Less invasive cross-sectional methods such as computed tomographic angiography and, more recently, three-dimensional magnetic resonance (MR) angiography can effectively demonstrate thickening of the vessel wall, which may be the earliest manifestation of the disease, occurring before stenosis and dilatation. MR imaging in particular allows better soft-tissue differentiation and can show other signs of inflammation, including mural edema and increased mural vascularity. Other advantages of MR imaging are the lack of iodinated contrast material or ionizing radiation.
© RSNA, 2004
Index Terms: Aorta, MR, 56.12142, 89.12142, 94.12942, 981.12942 • Aorta, stenosis or obstruction, 56.625, 89.625, 94.625, 981.625 • Aortitis, 56.625, 89.625, 94.625, 981.625 • Takayasu arteritis, 56.625, 89.625, 94.625, 981.625
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LEARNING OBJECTIVES FOR TEST 5
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After reading this article and taking the test, the reader will be able to:
- List the epidemiologic, pathophysiologic, etiologic, and clinical features of Takayasu arteritis.
- Describe the current classification system for Takayasu arteritis.
- Identify the common MR angiographic findings in the various types of Takayasu arteritis.
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Introduction
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Takayasu arteritis is a type of chronic granulomatous arteritis that has significant morbidity and mortality rates in affected patients, mainly due to ischemic disorders of the involved vessels (1). Because the clinical presentation of Takayasu arteritis and results of laboratory tests at the onset of the disease are typically nonspecific, accurate diagnosis virtually always depends on imaging studies. Although the diagnosis of Takayasu arteritis has largely been based on characteristic findings seen at conventional angiography, the more recent use of methods that can also provide cross-sectional information (ie, computed tomography [CT] or magnetic resonance [MR] angiography) has increased detection in the early systemic phase, when inflammation or thickening of the vessel wall may already be seen in the absence of luminal abnormalities (2).
In this article, we review the basic concepts of Takayasu arteritis and the technique of three-dimensional (3D) MR angiography. We then briefly compare 3D MR angiography with other methods in the diagnosis and follow-up of the disease and illustrate the most important 3D MR imaging findings in a variety of patient studies.
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Definition
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Also known by the terms pulseless disease, occlusive thromboaortopathy, and Martorell syndrome, Takayasu arteritis is a chronic, progressive, inflammatory, and obliterative disease of large vessels, with a predilection for the aorta and its major branches. The process may also involve the coronary and pulmonary arteries. The disease was scientifically described in 1908, when the Japanese ophthalmologist Mikito Takayasu reported the association of retinal arteriovenous anastomoses and absent upper-extremity pulses (1,3–5).
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Epidemiologic Features
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Takayasu arteritis is rare. The incidence in the United States was once estimated at 2.6 cases per 1,000,000 population per year (4,6). The disease is more often observed in patients of Asian origin, but it has been described in all racial groups. It is most commonly seen in Japan, Southeast Asia, India, and South and Central American countries, including Mexico, Peru, and Brazil. Females make up 80%–90% of patients with Takayasu arteritis, mostly in the second and third decades of life. Men are rarely affected (4). Nevertheless, the disease has been reported in children as young as 6 months and in adults of every age (2,4). The female-to-male ratio appears to decline from Eastern Asia toward the West (4). Given the low prevalence, mortality and morbidity data are limited.
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Pathophysiologic and Etiologic Features
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Takayasu arteritis is characterized by granulomatous inflammation of the arterial wall with marked intimal proliferation and fibrosis of the media and adventitia, which eventually leads to stenosis, occlusion, and, occasionally, poststenotic dilatations and aneurysm formation (when inflammation destroys the media). The lesions tend to be segmental with a patchy distribution (1,4).
A specific cause has not yet been found. Most likely, the inflammatory process has an autoimmune origin, as a genetically predisposed immune response to hypothetical antigens deposited in arterial walls, in which cellular and humoral mechanisms take part (4). Infection has been considered to play a role in the pathogenesis: Tuberculosis may represent a possible etiologic factor, given the high prevalence of this infection in affected patients. The disease has also been associated with viral and streptococcal infections, rheumatic fever, and rheumatoid arthritis (7).
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Clinical Features
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The clinical manifestations of Takayasu arteritis are usually divided into early and late phases, with a classic triphasic pattern of expression. This consists of an early or prepulseless phase (characterized by nonspecific systemic features such as low-grade fever, malaise, weight loss, and fatigue), a vascular inflammatory phase, and a late quiescent and occlusive phase (2). However, this sequential presentation is likely to occur only in a minority of patients because the disease is usually recurrent, leading to coexistence of the various phases at one time (2). A variable interval (months to years) may separate the acute from the occlusive phases, in which vascular insufficiency develops. Symptoms of vascular compromise may be minimized by the development of collateral circulation with the slow onset of stenosis. The lack of specificity of early symptoms tends to delay the diagnosis, which is most frequently made during the late stage (4).
Characteristic features at the late, fibrotic phase include diminished or absent pulses (associated with limb claudications and blood pressure discrepancies), vascular bruits, hypertension (due to renal artery stenosis), mesenteric angina, retinopathy, aortic regurgitation (when the ascending aorta is involved), dilated cardiomyopathy, myocarditis, pericarditis, congestive heart failure, neurologic symptoms secondary to hypertension or ischemia (postural dizziness, seizures, amaurosis), myocardial ischemia, renal glomerular lesions, interstitial lung disease, pneumonic consolidations, ulcerative colitis, and erythema nodosum (4,8). Clinically, hypertension, stroke, and aortic insufficiency warrant close attention, as these vascular complications often lead to mortality.
As an aid to establishing the clinical diagnosis, several criteria have been proposed. The Ishikawa diagnostic criteria modified by Sharma et al (8) (1995) are currently the most commonly adopted (Table 1).
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Classification
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Various attempts have been made to classify the disease on the basis of angiographic findings, which may be helpful in planning surgery, albeit offering little information on prognosis (3,9,10).
The most recently devised classification was suggested in 1996 by Numano’s group, which divided the disease into six types (Fig 1) (11,12):
Type I involves only the branches of the aortic arch.
Type IIa involves the aorta only at its ascending portion and/or at the aortic arch. The branches of the aortic arch may be involved as well. The rest of the aorta is not affected.
Type IIb affects the descending thoracic aorta with or without involvement of the ascending aorta or the aortic arch with its branches. The abdominal aorta is not involved.
Type III is concomitant involvement of the descending thoracic aorta, the abdominal aorta, and/or the renal arteries. The ascending aorta and the aortic arch and its branches are not involved.
Type IV involves only the abdominal aorta and/or the renal arteries.
Type V is a generalized type, with combined features of the other types.
Note: Involvement of the coronary and pulmonary arteries should be indicated as C(+) or P(+), respectively.
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Diagnosis
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Laboratory Studies
Concentrations of C-reactive protein may be raised and the erythrocyte sedimentation rate may be accelerated, but they correlate poorly with disease activity; no known serologic test has been able to supplant vascular histopathologic analysis in determining active inflammation. Takayasu arteritis has no specific serum markers (1,4).
Imaging Studies
Nuclear Medicine.—
Gallium-67 radionuclide scanning may show increased uptake in the aorta and its branches when there is some degree of active inflammation (13).
Ultrasonography.—
Duplex Doppler ultrasonography (US) may be used to identify circumferential vessel wall thickening and thereby evaluate and monitor disease in the aorta and branch vessels (Fig 2). However, the examination is operator dependent and also depends on a suitable acoustic window. Furthermore, it has a low negative predictive value (14).
Angiography.—
Conventional or digital subtraction angiography has been the standard imaging tool for the diagnosis and evaluation of Takayasu arteritis (Fig 3) (15,16). Total aortography (including the origins of the arch vessels, the abdominal visceral branches, and the iliac arteries) and pulmonary arteriography are usually recommended for accurate assessment of disease extent.
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Figure 3. Type I Takayasu arteritis in a 31-year-old woman. Coronal digital subtraction angiogram of the supraaortic vessels shows focal stenosis of the proximal portion of the left subclavian artery (large arrow). The right subclavian artery is aberrant. There is severe stenosis at the origin of the right vertebral artery (small arrow). The right common carotid artery (arrowheads) is almost occluded at its origin and is retrogradely filled by collateral vessels.
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Nevertheless, angiography is an invasive method that carries well-known risks of complications resulting from the procedure itself, such as hematoma, arteriovenous fistula, pseudoaneurysm, and vessel thrombosis. The reported overall prevalence of a major vascular complication is 0.02%–9% (17,18). The frequency of death related to the method is low (<0.05%) (19). Moreover, it demonstrates only the appearance of the lumen and does not allow differentiation between active and inactive lesions; results may be normal in cases of diffuse mural thickening without any luminal changes, which can be observed in the early phases. Other potential drawbacks of the method are cumulative exposure to ionizing radiation and morbidity from use of iodinated contrast media, which includes nephrotoxicity. The overall prevalence of adverse reactions to contrast media is as high as 5% with high-osmolarity contrast agents and 1%–2% with low-osmolarity contrast agents. The mortality rate is 1/40,000–170,000 with high-osmolarity contrast agents and 1/200,000–300,000 with low-osmolarity contrast agents (20).
Computed Tomography.—
Conventional axial CT scans may demonstrate mural thickening of the aorta, as well as luminal narrowing. Use of contrast material may reveal enhancing inflammatory lesions in the early stage of the disease, prior to the development of stenoses (Fig 4).
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Figure 4a. Type IIb Takayasu arteritis with pulmonary artery involvement in a 30-year-old woman. (a) Axial contrast material-enhanced multidetector-row CT scan shows stenosis and wall thickening of the left common carotid artery at its origin (arrow). (b, c) Axial contrast-enhanced multidetector-row CT scans (b obtained at a higher level than c) show occlusion of the right descending interlobar artery (arrow). (d) Axial contrast-enhanced multidetector-row CT scan from the same examination shows absence of enhanced vessels in the right lower lobe. There is also mild wall thickening of the descending thoracic aorta.
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Figure 4b. Type IIb Takayasu arteritis with pulmonary artery involvement in a 30-year-old woman. (a) Axial contrast material-enhanced multidetector-row CT scan shows stenosis and wall thickening of the left common carotid artery at its origin (arrow). (b, c) Axial contrast-enhanced multidetector-row CT scans (b obtained at a higher level than c) show occlusion of the right descending interlobar artery (arrow). (d) Axial contrast-enhanced multidetector-row CT scan from the same examination shows absence of enhanced vessels in the right lower lobe. There is also mild wall thickening of the descending thoracic aorta.
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Figure 4c. Type IIb Takayasu arteritis with pulmonary artery involvement in a 30-year-old woman. (a) Axial contrast material-enhanced multidetector-row CT scan shows stenosis and wall thickening of the left common carotid artery at its origin (arrow). (b, c) Axial contrast-enhanced multidetector-row CT scans (b obtained at a higher level than c) show occlusion of the right descending interlobar artery (arrow). (d) Axial contrast-enhanced multidetector-row CT scan from the same examination shows absence of enhanced vessels in the right lower lobe. There is also mild wall thickening of the descending thoracic aorta.
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Figure 4d. Type IIb Takayasu arteritis with pulmonary artery involvement in a 30-year-old woman. (a) Axial contrast material-enhanced multidetector-row CT scan shows stenosis and wall thickening of the left common carotid artery at its origin (arrow). (b, c) Axial contrast-enhanced multidetector-row CT scans (b obtained at a higher level than c) show occlusion of the right descending interlobar artery (arrow). (d) Axial contrast-enhanced multidetector-row CT scan from the same examination shows absence of enhanced vessels in the right lower lobe. There is also mild wall thickening of the descending thoracic aorta.
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Helical CT angiography has also been shown to be sensitive and specific in the diagnosis of Takayasu arteritis, especially after the introduction of high-resolution multidetector-row CT arrays. Despite being less invasive than conventional angiography, the method still requires the use of potentially hazardous iodinated contrast material and radiation (21–24).
MR Imaging.—
Similar to CT, MR imaging is a noninvasive examination that can provide information on vessel wall thickening (even before lumen changes become apparent), luminal narrowing, and luminal dilatation (Figs 5–12) (25–28).Enhancement of the thickened walls with gadolinium contrast material can be seen when some degree of activity is present. This can be more easily demonstrated at fat-suppressed T1-weighted imaging with a delay after injection of gadolinium contrast material, which depicts progressive accumulation and delayed washout of contrast medium (29). However, MR imaging has two important advantages over CT and conventional angiography: (a) Paramagnetic contrast media rarely cause anaphylactic reactions and are nonnephrotoxic and (b) ionizing radiation is not used.
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Figure 5a. Type I Takayasu arteritis. (a) Coronal maximum intensity projection (MIP) 3D MR angiogram of a 33-year-old woman shows significant stenosis of the right common carotid artery at its origin (small arrow). The left subclavian artery has two stenotic segments (large arrows) with a small area of poststenotic dilatation in between. There are also some luminal irregularities of the left common carotid artery. (b) Coronal MIP 3D MR angiogram of a 23-year-old woman shows irregularities of the distal portion of the brachiocephalic trunk (left small arrow) and of the left common carotid artery (right small arrow). There is an abrupt stenosis at the origin of the left subclavian artery (large arrow). (c) Coronal MIP 3D MR angiogram of a 35-year-old woman shows high-grade stenosis of the left common carotid artery (arrow). (d) Axial T1-weighted MR image (obtained before administration of gadolinium contrast material) of the same patient as in c shows wall thickening of the left common carotid artery (arrow).
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Figure 5b. Type I Takayasu arteritis. (a) Coronal maximum intensity projection (MIP) 3D MR angiogram of a 33-year-old woman shows significant stenosis of the right common carotid artery at its origin (small arrow). The left subclavian artery has two stenotic segments (large arrows) with a small area of poststenotic dilatation in between. There are also some luminal irregularities of the left common carotid artery. (b) Coronal MIP 3D MR angiogram of a 23-year-old woman shows irregularities of the distal portion of the brachiocephalic trunk (left small arrow) and of the left common carotid artery (right small arrow). There is an abrupt stenosis at the origin of the left subclavian artery (large arrow). (c) Coronal MIP 3D MR angiogram of a 35-year-old woman shows high-grade stenosis of the left common carotid artery (arrow). (d) Axial T1-weighted MR image (obtained before administration of gadolinium contrast material) of the same patient as in c shows wall thickening of the left common carotid artery (arrow).
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Figure 5c. Type I Takayasu arteritis. (a) Coronal maximum intensity projection (MIP) 3D MR angiogram of a 33-year-old woman shows significant stenosis of the right common carotid artery at its origin (small arrow). The left subclavian artery has two stenotic segments (large arrows) with a small area of poststenotic dilatation in between. There are also some luminal irregularities of the left common carotid artery. (b) Coronal MIP 3D MR angiogram of a 23-year-old woman shows irregularities of the distal portion of the brachiocephalic trunk (left small arrow) and of the left common carotid artery (right small arrow). There is an abrupt stenosis at the origin of the left subclavian artery (large arrow). (c) Coronal MIP 3D MR angiogram of a 35-year-old woman shows high-grade stenosis of the left common carotid artery (arrow). (d) Axial T1-weighted MR image (obtained before administration of gadolinium contrast material) of the same patient as in c shows wall thickening of the left common carotid artery (arrow).
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Figure 5d. Type I Takayasu arteritis. (a) Coronal maximum intensity projection (MIP) 3D MR angiogram of a 33-year-old woman shows significant stenosis of the right common carotid artery at its origin (small arrow). The left subclavian artery has two stenotic segments (large arrows) with a small area of poststenotic dilatation in between. There are also some luminal irregularities of the left common carotid artery. (b) Coronal MIP 3D MR angiogram of a 23-year-old woman shows irregularities of the distal portion of the brachiocephalic trunk (left small arrow) and of the left common carotid artery (right small arrow). There is an abrupt stenosis at the origin of the left subclavian artery (large arrow). (c) Coronal MIP 3D MR angiogram of a 35-year-old woman shows high-grade stenosis of the left common carotid artery (arrow). (d) Axial T1-weighted MR image (obtained before administration of gadolinium contrast material) of the same patient as in c shows wall thickening of the left common carotid artery (arrow).
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Figure 6a. Type IIa Takayasu arteritis in a 27-year-old woman. Axial unenhanced (a) and gadolinium-enhanced (b) T1-weighted MR images show wall thickening of the ascending aorta (arrow), which is enhanced on the gadolinium-enhanced image (b).
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Figure 6b. Type IIa Takayasu arteritis in a 27-year-old woman. Axial unenhanced (a) and gadolinium-enhanced (b) T1-weighted MR images show wall thickening of the ascending aorta (arrow), which is enhanced on the gadolinium-enhanced image (b).
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Figure 7a. Type IIb Takayasu arteritis in a 24-year-old man. (a) Coronal MIP 3D MR angiogram shows stenosis at the origin of the right subclavian artery (small arrow). There is also diffuse narrowing of both common carotid arteries (arrowheads) and focal stenosis of the left subclavian artery (large arrow). (b) Sagittal MIP 3D MR angiogram from the same examination shows stenosis of the descending thoracic aorta (arrowhead). (c) Sagittal T1-weighted MR image (obtained before administration of gadolinium contrast material) shows thickening of the aortic wall.
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Figure 7b. Type IIb Takayasu arteritis in a 24-year-old man. (a) Coronal MIP 3D MR angiogram shows stenosis at the origin of the right subclavian artery (small arrow). There is also diffuse narrowing of both common carotid arteries (arrowheads) and focal stenosis of the left subclavian artery (large arrow). (b) Sagittal MIP 3D MR angiogram from the same examination shows stenosis of the descending thoracic aorta (arrowhead). (c) Sagittal T1-weighted MR image (obtained before administration of gadolinium contrast material) shows thickening of the aortic wall.
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Figure 7c. Type IIb Takayasu arteritis in a 24-year-old man. (a) Coronal MIP 3D MR angiogram shows stenosis at the origin of the right subclavian artery (small arrow). There is also diffuse narrowing of both common carotid arteries (arrowheads) and focal stenosis of the left subclavian artery (large arrow). (b) Sagittal MIP 3D MR angiogram from the same examination shows stenosis of the descending thoracic aorta (arrowhead). (c) Sagittal T1-weighted MR image (obtained before administration of gadolinium contrast material) shows thickening of the aortic wall.
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Figure 8a. Type III Takayasu arteritis. (a) Coronal MIP 3D MR angiogram of a 30-year-old woman shows irregular dilatation of the descending thoracic aorta and proximal abdominal aorta. (b) Oblique MIP 3D MR angiogram of a 10-year-old girl shows diffuse narrowing of the descending thoracic and abdominal aorta (arrowheads) and the common iliac arteries with an aortoaortic graft (arrows). (c) Oblique MIP 3D MR angiogram of a 34-year-old woman shows irregular dilatation of the descending thoracic aorta and proximal abdominal aorta and narrowing of the infrarenal aorta. (d) Axial T1-weighted MR image of the same patient as in c shows the narrowed infrarenal aorta (arrow).
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Figure 8b. Type III Takayasu arteritis. (a) Coronal MIP 3D MR angiogram of a 30-year-old woman shows irregular dilatation of the descending thoracic aorta and proximal abdominal aorta. (b) Oblique MIP 3D MR angiogram of a 10-year-old girl shows diffuse narrowing of the descending thoracic and abdominal aorta (arrowheads) and the common iliac arteries with an aortoaortic graft (arrows). (c) Oblique MIP 3D MR angiogram of a 34-year-old woman shows irregular dilatation of the descending thoracic aorta and proximal abdominal aorta and narrowing of the infrarenal aorta. (d) Axial T1-weighted MR image of the same patient as in c shows the narrowed infrarenal aorta (arrow).
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Figure 8c. Type III Takayasu arteritis. (a) Coronal MIP 3D MR angiogram of a 30-year-old woman shows irregular dilatation of the descending thoracic aorta and proximal abdominal aorta. (b) Oblique MIP 3D MR angiogram of a 10-year-old girl shows diffuse narrowing of the descending thoracic and abdominal aorta (arrowheads) and the common iliac arteries with an aortoaortic graft (arrows). (c) Oblique MIP 3D MR angiogram of a 34-year-old woman shows irregular dilatation of the descending thoracic aorta and proximal abdominal aorta and narrowing of the infrarenal aorta. (d) Axial T1-weighted MR image of the same patient as in c shows the narrowed infrarenal aorta (arrow).
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Figure 8d. Type III Takayasu arteritis. (a) Coronal MIP 3D MR angiogram of a 30-year-old woman shows irregular dilatation of the descending thoracic aorta and proximal abdominal aorta. (b) Oblique MIP 3D MR angiogram of a 10-year-old girl shows diffuse narrowing of the descending thoracic and abdominal aorta (arrowheads) and the common iliac arteries with an aortoaortic graft (arrows). (c) Oblique MIP 3D MR angiogram of a 34-year-old woman shows irregular dilatation of the descending thoracic aorta and proximal abdominal aorta and narrowing of the infrarenal aorta. (d) Axial T1-weighted MR image of the same patient as in c shows the narrowed infrarenal aorta (arrow).
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Figure 9a. Type IV Takayasu arteritis. (a) Oblique MIP 3D MR angiogram of a 32-year-old woman shows occlusion of the infrarenal aorta (arrow). The right kidney is not visualized. (b) Coronal MIP 3D MR angiogram of a 19-year-old woman shows irregular dilatation of the abdominal aorta and iliac arteries. Each renal artery has a short stenotic segment at its origin (arrows). (c) Sagittal 3D MR angiogram of a 30-year-old man shows a long stenotic segment of the superior mesenteric artery (arrowheads) and focal stenosis of the celiac trunk (arrow). (d) Coronal MIP 3D MR angiogram of a 21-year-old woman shows irregular stenosis of the abdominal aorta (arrows) and common iliac arteries (arrowheads). The right kidney is small due to concomitant involvement of the renal artery.
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Figure 9b. Type IV Takayasu arteritis. (a) Oblique MIP 3D MR angiogram of a 32-year-old woman shows occlusion of the infrarenal aorta (arrow). The right kidney is not visualized. (b) Coronal MIP 3D MR angiogram of a 19-year-old woman shows irregular dilatation of the abdominal aorta and iliac arteries. Each renal artery has a short stenotic segment at its origin (arrows). (c) Sagittal 3D MR angiogram of a 30-year-old man shows a long stenotic segment of the superior mesenteric artery (arrowheads) and focal stenosis of the celiac trunk (arrow). (d) Coronal MIP 3D MR angiogram of a 21-year-old woman shows irregular stenosis of the abdominal aorta (arrows) and common iliac arteries (arrowheads). The right kidney is small due to concomitant involvement of the renal artery.
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Figure 9c. Type IV Takayasu arteritis. (a) Oblique MIP 3D MR angiogram of a 32-year-old woman shows occlusion of the infrarenal aorta (arrow). The right kidney is not visualized. (b) Coronal MIP 3D MR angiogram of a 19-year-old woman shows irregular dilatation of the abdominal aorta and iliac arteries. Each renal artery has a short stenotic segment at its origin (arrows). (c) Sagittal 3D MR angiogram of a 30-year-old man shows a long stenotic segment of the superior mesenteric artery (arrowheads) and focal stenosis of the celiac trunk (arrow). (d) Coronal MIP 3D MR angiogram of a 21-year-old woman shows irregular stenosis of the abdominal aorta (arrows) and common iliac arteries (arrowheads). The right kidney is small due to concomitant involvement of the renal artery.
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Figure 9d. Type IV Takayasu arteritis. (a) Oblique MIP 3D MR angiogram of a 32-year-old woman shows occlusion of the infrarenal aorta (arrow). The right kidney is not visualized. (b) Coronal MIP 3D MR angiogram of a 19-year-old woman shows irregular dilatation of the abdominal aorta and iliac arteries. Each renal artery has a short stenotic segment at its origin (arrows). (c) Sagittal 3D MR angiogram of a 30-year-old man shows a long stenotic segment of the superior mesenteric artery (arrowheads) and focal stenosis of the celiac trunk (arrow). (d) Coronal MIP 3D MR angiogram of a 21-year-old woman shows irregular stenosis of the abdominal aorta (arrows) and common iliac arteries (arrowheads). The right kidney is small due to concomitant involvement of the renal artery.
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Figure 10a. Type IV Takayasu arteritis in a 25-year-old woman. (a) Coronal MIP 3D MR angiogram shows narrowing of the abdominal aorta (arrow). The narrowing starts below the celiac trunk and is associated with stenosis of the renal arteries (top arrowheads) and the left common iliac artery (bottom arrowhead). There are also luminal irregularities of the right common iliac artery; the left nephrogram is barely visible. (b-e) Axial unenhanced (b, c) and gadolinium-enhanced (d, e) T1-weighted MR images (b and d obtained at a higher level than c and e) show thickening of the aortic wall with involvement of adjacent tissues (arrow in b and c). These structures are enhanced on the gadolinium-enhanced images (arrow in d and e), a finding that denotes inflammation.
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Figure 10b. Type IV Takayasu arteritis in a 25-year-old woman. (a) Coronal MIP 3D MR angiogram shows narrowing of the abdominal aorta (arrow). The narrowing starts below the celiac trunk and is associated with stenosis of the renal arteries (top arrowheads) and the left common iliac artery (bottom arrowhead). There are also luminal irregularities of the right common iliac artery; the left nephrogram is barely visible. (b-e) Axial unenhanced (b, c) and gadolinium-enhanced (d, e) T1-weighted MR images (b and d obtained at a higher level than c and e) show thickening of the aortic wall with involvement of adjacent tissues (arrow in b and c). These structures are enhanced on the gadolinium-enhanced images (arrow in d and e), a finding that denotes inflammation.
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Figure 10c. Type IV Takayasu arteritis in a 25-year-old woman. (a) Coronal MIP 3D MR angiogram shows narrowing of the abdominal aorta (arrow). The narrowing starts below the celiac trunk and is associated with stenosis of the renal arteries (top arrowheads) and the left common iliac artery (bottom arrowhead). There are also luminal irregularities of the right common iliac artery; the left nephrogram is barely visible. (b-e) Axial unenhanced (b, c) and gadolinium-enhanced (d, e) T1-weighted MR images (b and d obtained at a higher level than c and e) show thickening of the aortic wall with involvement of adjacent tissues (arrow in b and c). These structures are enhanced on the gadolinium-enhanced images (arrow in d and e), a finding that denotes inflammation.
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Figure 10d. Type IV Takayasu arteritis in a 25-year-old woman. (a) Coronal MIP 3D MR angiogram shows narrowing of the abdominal aorta (arrow). The narrowing starts below the celiac trunk and is associated with stenosis of the renal arteries (top arrowheads) and the left common iliac artery (bottom arrowhead). There are also luminal irregularities of the right common iliac artery; the left nephrogram is barely visible. (b-e) Axial unenhanced (b, c) and gadolinium-enhanced (d, e) T1-weighted MR images (b and d obtained at a higher level than c and e) show thickening of the aortic wall with involvement of adjacent tissues (arrow in b and c). These structures are enhanced on the gadolinium-enhanced images (arrow in d and e), a finding that denotes inflammation.
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Figure 10e. Type IV Takayasu arteritis in a 25-year-old woman. (a) Coronal MIP 3D MR angiogram shows narrowing of the abdominal aorta (arrow). The narrowing starts below the celiac trunk and is associated with stenosis of the renal arteries (top arrowheads) and the left common iliac artery (bottom arrowhead). There are also luminal irregularities of the right common iliac artery; the left nephrogram is barely visible. (b-e) Axial unenhanced (b, c) and gadolinium-enhanced (d, e) T1-weighted MR images (b and d obtained at a higher level than c and e) show thickening of the aortic wall with involvement of adjacent tissues (arrow in b and c). These structures are enhanced on the gadolinium-enhanced images (arrow in d and e), a finding that denotes inflammation.
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Figure 11a. Type V Takayasu arteritis. (a) Oblique MIP 3D MR angiogram of a 19-year-old woman shows irregular narrowing of the descending thoracic aorta and abdominal aorta with scattered areas of small aneurysms. The marginal artery of Drummond is prominent (arrow). (b) Sagittal MIP 3D MR angiogram from the same examination shows concomitant involvement of the supraaortic branches. (c, d) Oblique MIP 3D MR angiograms (c obtained at a higher level than d) of a 31-year-old woman show irregular dilatation and kinking of the entire aorta.
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Figure 11b. Type V Takayasu arteritis. (a) Oblique MIP 3D MR angiogram of a 19-year-old woman shows irregular narrowing of the descending thoracic aorta and abdominal aorta with scattered areas of small aneurysms. The marginal artery of Drummond is prominent (arrow). (b) Sagittal MIP 3D MR angiogram from the same examination shows concomitant involvement of the supraaortic branches. (c, d) Oblique MIP 3D MR angiograms (c obtained at a higher level than d) of a 31-year-old woman show irregular dilatation and kinking of the entire aorta.
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Figure 11c. Type V Takayasu arteritis. (a) Oblique MIP 3D MR angiogram of a 19-year-old woman shows irregular narrowing of the descending thoracic aorta and abdominal aorta with scattered areas of small aneurysms. The marginal artery of Drummond is prominent (arrow). (b) Sagittal MIP 3D MR angiogram from the same examination shows concomitant involvement of the supraaortic branches. (c, d) Oblique MIP 3D MR angiograms (c obtained at a higher level than d) of a 31-year-old woman show irregular dilatation and kinking of the entire aorta.
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Figure 11d. Type V Takayasu arteritis. (a) Oblique MIP 3D MR angiogram of a 19-year-old woman shows irregular narrowing of the descending thoracic aorta and abdominal aorta with scattered areas of small aneurysms. The marginal artery of Drummond is prominent (arrow). (b) Sagittal MIP 3D MR angiogram from the same examination shows concomitant involvement of the supraaortic branches. (c, d) Oblique MIP 3D MR angiograms (c obtained at a higher level than d) of a 31-year-old woman show irregular dilatation and kinking of the entire aorta.
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Figure 12a. Type V Takayasu arteritis. (a, b) Coronal (a) and sagittal (b) MIP 3D MR angiograms of a 31-year-old woman show two stenotic segments of the right subclavian artery (arrowheads in a), occlusion of the left subclavian artery (arrow), and narrowing of the descending thoracic and abdominal aorta (arrowhead in b). (c) Axial double inversion recovery fast spin-echo MR image of the same patient shows thickening of the aortic wall (arrow). (d) Oblique MIP 3D MR angiogram of a 35-year-old woman shows dilatation of the ascending aorta (small arrows) and diffuse and subtle narrowing of the descending thoracic and abdominal aorta (large arrows).
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Figure 12b. Type V Takayasu arteritis. (a, b) Coronal (a) and sagittal (b) MIP 3D MR angiograms of a 31-year-old woman show two stenotic segments of the right subclavian artery (arrowheads in a), occlusion of the left subclavian artery (arrow), and narrowing of the descending thoracic and abdominal aorta (arrowhead in b). (c) Axial double inversion recovery fast spin-echo MR image of the same patient shows thickening of the aortic wall (arrow). (d) Oblique MIP 3D MR angiogram of a 35-year-old woman shows dilatation of the ascending aorta (small arrows) and diffuse and subtle narrowing of the descending thoracic and abdominal aorta (large arrows).
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Figure 12c. Type V Takayasu arteritis. (a, b) Coronal (a) and sagittal (b) MIP 3D MR angiograms of a 31-year-old woman show two stenotic segments of the right subclavian artery (arrowheads in a), occlusion of the left subclavian artery (arrow), and narrowing of the descending thoracic and abdominal aorta (arrowhead in b). (c) Axial double inversion recovery fast spin-echo MR image of the same patient shows thickening of the aortic wall (arrow). (d) Oblique MIP 3D MR angiogram of a 35-year-old woman shows dilatation of the ascending aorta (small arrows) and diffuse and subtle narrowing of the descending thoracic and abdominal aorta (large arrows).
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Figure 12d. Type V Takayasu arteritis. (a, b) Coronal (a) and sagittal (b) MIP 3D MR angiograms of a 31-year-old woman show two stenotic segments of the right subclavian artery (arrowheads in a), occlusion of the left subclavian artery (arrow), and narrowing of the descending thoracic and abdominal aorta (arrowhead in b). (c) Axial double inversion recovery fast spin-echo MR image of the same patient shows thickening of the aortic wall (arrow). (d) Oblique MIP 3D MR angiogram of a 35-year-old woman shows dilatation of the ascending aorta (small arrows) and diffuse and subtle narrowing of the descending thoracic and abdominal aorta (large arrows).
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Moreover, imaging data can be obtained in multiple planes, soft-tissue differentiation is better, and there is increased sensitivity in the detection of mural edema, which may appear in the examinations of many patients with Takayasu arteritis as high signal intensity on T2-weighted images, although it is not clear if vessel wall edema significantly correlates with disease activity (25,30,31). Reconstruction of projection images from an MR angiography data set is simpler than reconstruction from a CT angiography data set, since there is no or very little signal from the structures surrounding the vessel. Longer imaging times, contraindications associated with electronic devices, and artifacts from surgical clips are the major disadvantages of this method (31).
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MR Imaging Techniques
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The most useful MR imaging techniques for evaluating large vessel inflammatory disease include the following (Table 2) (31):
1. T2-weighted fat-suppressed multiplanar sequences are used to detect vessel wall edema.
2. Pre- and postcontrast T1-weighted fast spoiled gradient-echo (FSPGR) or fast spin-echo (FSE) double inversion recovery (IR) multiplanar sequences are used to detect vessel wall thickening and enhancement by the intravenous contrast material. The double IR technique nulls the signal from blood, providing better assessment of vessel wall thickness. The drawback of this technique is the longer examination time caused by the need for sequential section acquisition.
3. MR angiography is used to evaluate luminal narrowing and dilatations. The contrast material used is derived from gadolinium chelates.
MR angiography techniques include the following (31): (a) two-dimensional time-of-flight (TOF) angiography without contrast material (which is not routinely employed in thoracic and abdominal studies due to limitations such as pulsatility artifacts, low signal-to-noise ratio, and loss of signal secondary to flow turbulence); and (b) 3D angiography with contrast material.
Three-dimensional MR angiography is equally or more sensitive than angiography in the detection of lesions in the aorta and its major branches, albeit less sensitive in demonstration of smaller branch involvement. A recent study estimated that body coil–based contrast-enhanced MR angiography has overall sensitivity of 84% in the detection of significant stenoses of the pelvic and lower limb peripheral arteries (32). A variety of techniques have been developed; the general technical elements are rapid sequential volume acquisitions before and after injection of contrast material followed by digital subtraction and postprocessing reformation (33–35).
Between September 2001 and March 2003, 29 patients with confirmed Takayasu arteritis underwent MR angiography in our departments of radiology. In these studies, which were performed on a 1.5-T unit (Signa Horizon LX; GE Medical Systems, Milwaukee, Wis), fast arterial imaging was achieved by using a thin-section 3D vascular time-of-flight (T1-weighted, gradient-echo) sequence with the following parameters: short echo time (<3 msec) and short repetition time, flip angle of 45°, bandwidth of 32–64 kHz, 0.5–1 signal acquired, and matrix (phase x frequency) of 128–160 x 256–512. The data were acquired during a 20–35-second breath hold, before ("mask" data) and after rapid bolus intravenous injection of a 0.1–0.3 mmol/kg dose of gadopentetate dimeglumine (Magnevist; Berlex Laboratories, Wayne, NJ). Imaging was performed with or without fat saturation.
The mask data set was obtained to be digitally subtracted from the arterial phase data set in order to reduce background signal a
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Abstract
LEARNING OBJECTIVES FOR TEST...
