CLINICAL IMAGING 1992;16:269-271

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MRI VERSUS CT AND US IN THE EVALUATION OF A PATIENT PRESENTING WITH SUPERIOR VENA CAVA SYNDROME CASE REPORT TASNEEM

KHIMJI,

MD,

AND JACOB ZEISS,

Three cross-sectional imaging modalities are compared in the evaluation of a patient with Superior Vena Cava Syndrome. The apparent and potential advantages of magnetic resonance imaging (MRI) over computer tomography (CT) and ultrasound (US) are discussed. KEY WORDS:

Magnetic resonance imaging; fibrosclerosis; Inflammatory vena cava syndrome

Cardiovascular; pseudotumor;

Multifocal Superior

CASE REPORT A 60-year-old white woman presented with dyspnea and bilateral upper extremity and neck edema. A clinical diagnosis of superior vena cava syndrome was made. Initial computed tomography (CT) and ultrasound (US) demonstrated thrombus in the right atrium with extension into the superior vena cava. The patient was started on anticoagulant therapy. Repeat CT and US were done 2 weeks later showing essentially no change; CT continued to show filling defect in both brachiocephalic veins and superior vena cava consistent with thrombus (Figure lA,B). Venogram (Figure 2), upon admission, demonstrated filling defects in both brachiocephalic veins and the superior vena cava and irregular filling defect in the right atrium suggestive of thrombus. Since no improvement was found clinically or on CT or US im-

From the Department of Radiology, Medical College of Ohio, Toledo, Ohio. Address reprint requests to: Tasneem Khimji, M.D., University Hospitals of Cleveland, Department of Radiology, 2074 Abington Road, Cleveland OH 44106. Received March 27, 1992; accepted April 14, 1992. 0 1992 by Elsevier Science Publishing Co., Inc. 655 Avenue of the Americas, New York, NY 10010 0899-7071/92/$5.00

MD

ages, concern was raised that the intracardiac and intravascular process may, in fact, represent a neoplastic process. An MRI of the chest was therefore performed. Multislice spin echo sequences, with cardiac gating and respiratory compensation, were utilized. This demonstrated homogeneous thickening of the entire right atria1 wall, with extension to the anterior wall of the right ventricle, on Tl-weighted images with increase in signal involving these areas on TZweighted images (Figures 3A,B, and 4). The left ventricular wall, in comparison, had a low signal on both Tl-weighted images and T&weighted images. The right atria1 chamber was extremely small. There was also an intermediate signal in the brachiocephalic veins and the superior vena cava with absence of the usual flow void on both Tl-weighted and TZweighted sequences. The patient was subsequently surgically explored. There was extensive and dense mediastinal fibrosis with marked and diffuse thickening of the right atria1 wall, anterior right ventricular wall, and the superior vena cava. Grossly, the appearance was that of an infiltrating process, most likely neoplastic. The endocardial surface of the right atrium was smooth and intact. Pathologic diagnosis from the right atria1 biopsy was inflammatory pseudotumor. The patient was discharged on steroids and anticoagulants. After being readmitted 3 weeks later with a perforated gastric ulcer and gastrocolic fistula, she expired. Final diagnosis after autopsy was multifocal fibrosclerosis involving the mediastinum, myocardium, kidneys, and mesenteric vessels.

DISCUSSION Multifocal fibrosclerosis, which includes entities such as retroperitoneal and mediastinal fibrosis, pseudotumor of the orbit, and Riedel’s thyroiditis,

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KHIMJI AND ZEISS

CLINICAL IMAGING VOL. 16, NO. 4

A FIGURE 1. (A) Dynamic contrast enhanced CT. Filling defect in superior vena cava. (B) Eccentric thickening of right atria1 wall.

is an uncommon entity of unknown etiology. It is reportedly associated with administration of methysergide (no such history in this patient), granulomatous diseases such as tuberculosis and histoplasmosis, aortic aneurysm, or aortic aneurysm surgery. Multifocal fibrosclerosis presenting as superior vena cava syndrome has been reported in the literature (1). However, no reports of involvement of myocardium, as in this case, are found in the literature. Gross or superficial appearance is that of neoplasm. Thus, histologic evaluation is mandatory, which is demonstrated by this case. Besides the uniqueness of the diagnosis and the cardiac involvement, this case also helps illustrate the importance of the use of a noninvasive, noncontrast imaging study in the evaluation of a patient such as this. Differentiation between intravascular and/orintracardiac tumor presents a diagnostic dilemma for clinicians in light of the obvious management and therapeutic implications. Echocardiography is the primary screening technique for patients with suspected cardiac mass. This case and those demonstrated by Gomes et al. (2), indicate that there is clearly a need for another noninvasive modality. The evaluation of cardiac tumors has resulted in equivocal results and false positive results when based on large echocardiographic series (3,4). Echocardiography is technically difficult in patients with emphysema and/or chest wall deformity. As in this case, masses may be missed if the acoustic impedance is similar to blood or endocardium.

FIGURE 2. Vena cava-gram via left subclavian vein injection. Irregular filling defect in left brachiocephalic vein, superior vena cava, and right atrium.

OCTOBER-DECEMBER 1992

MRI FOR EVALUATING SUPERIOR VENA CAVA SYNDROME

FIGURE 3. (A) Tl-weighted

MRI scan. Homogeneous, concentric thickening of right atria1 wall. (B) T2-weighted MRI. High signal thickening of right atria1 and anterior right ventricular wall. Low to intermediate signal of normal left ventricular wall.

Cross

CT imaging by contrast enhanced to accurately delineating the and cardiac anatomy, also demonstrates asfindings in the chest that may help in diag-

sectional

or by MRI, in addition vascular sociated nosis.

An important advantage of MRI over CT is the ability to demonstrate vascular structures without the need for intravenous contrast. The presence of flow void suggests patency and, as in this case, the absence

FIGURE 4. Tl-weighted MRI with gadolinium enhancement. Increased signal of thickened right atria1 and right ventricular wall, compared to low signal intensity of left ventricular wall.

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of flow void suggests occlusion. Signal intensity, though potentially helpful, has not yet proved to be unequivocally helpful (2). In the present case it suggested unequivocally an infiltrative process in the wall limited to the right side of the heart and involving the superior vena cava and brachiocephalic veins. The present case supports the premise that MRI can play an important role in the evaluation of patients with suspected cardiac or vascular masses. It is particularly helpful in cases in which echocardiographic findings are equivocal or the clinical course deviates from that which is expected. Signal intensity remains a potential benefit in aiding diagnoses. Up unt,il now, however, signal intensity has proved to be nonspecific and also quite variable, depending on image sequences, technology, and software employed. It is hoped that with the ongoing surge in interest in this modality, it may eventually become an important aspect of diagnosis. Authors thank Mrs. Randy Morris and Mrs. Lois Haidet for photographs and manuscript preparation.

REFERENCES Schowengerdt CG, Suyemoto R, Main FB. Granulomatous and fibrous mediastinitis. A review and analysis of 180 cases. J. Thorac Cardiovasc Surg 1969;57:365. Gomes AS, Lois JF, Child JS, Brown K, Batra P. Cardiac tumors and thrombus: Evaluation with MR Imaging. AJR 1987;149: 895-899. Fyke FE, Seward JB, Edwards WD. Primary tumors: Experience with 36 consecutive patients since the introduction of twodimensional echocardiography. J Am Co11 Cardiol 1985;5: 1465-1473.

Asinger RW, Mike11 FL, Sharma B, Hodges M. Observations on detecting left ventricular thrombus with two dimensional echocardiography: Emphasis on avoidance of false positive diagnoses. Am J Cardiol 1981;47:145-156.

MRI versus CT and US in the evaluation of a patient presenting with superior vena cava syndrome. Case report.

Three cross-sectional imaging modalities are compared in the evaluation of a patient with Superior Vena Cava Syndrome. The apparent and potential adva...
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