Cine-Magnetic Resonance Imaging of Cor Triatriatum

in AIDS patients outweigh the risk of developing atypical P-carinii pulmonary involvement. Finally, videothoracoscopy with talc poudrage seems to offer some therapeutic benefit in this type of pneumothorax often refractory to simple drainage. Chemical pleurodesis with tetracycline solution via the chest tube had been successful in seven of nine AIDS patients treated by Wait and Estrera.5 The alternative of thoracoscopic talc poudrage has already proved its usefulness in primary spontaneous pneumothorax. 17 Tunon-de-Lara et al 18 reported a single case of successful talc pleurodesis in a patient with PCP and pneumothorax in whom chest tube insertion failed to maintain lung reexpansion. In our series, pneumothorax resolved after thoracoscopic talc poudrage in three of the five pneumothoraces with microbiologic proven P-carinii-related origin. The high rate of successful thoracotomy (13/14) in the hands of Crawford and his colleagues3 suggests that surgery remains the final alternative for those who fail thoracoscopic therapy. In essence, active PCP appears to be a significant cause of spontaneous pneumothorax in patients with AIDS. Videothoracoscopy can be of benefit in clarifying the etiology of the pneumothorax and directing appropriate therapy. Further, thoracoscopy is easily followed by talc poudrage which appears to have greater success in treating these patients than simple chest tube drainage. Clearly , thoracoscopy is a less invasive procedure than thoracotomy and may prove to be the logical following step to take in these very ill patients in whom standard chest tube drainage fails.

l l Eng RHK, Bishburg E, Smith SM. Evidence for destruction of

12 13

14 15 16 17 18

lung tissues during Pneumocystis carinii infection. Arch Intern Med 1987; 147:746-49 Scannell KA. Pneumothoraces and Pneumocystis carinii pneumonia in two AIDS patients receiving aerosolized pentamidine. Chest 1990; 97:479-80 Abd AG, Nierman DM, Ilowite JS, Pierson RN Jr, Loomis Bell AL Jr. Bilateral upper lobe Pneumocystis carinii pneumonia in a patient receiving inhaled pentamidine prophylaxis. Chest 1988; 94:329-31 Boutin C, Viallat JR, Aelony Y. Thoracoscopy technique. In: Boutin C, Viallat JR, Aelony Y, eds. Practical thoracoscopy. Berlin: Springer-Verlag, 1991; 13-41 Gurney JW, Bates FT. Pulmonary cystic disease: comparison of Pneumocystis carinii pneumatoceles and bullous emphysema due to intravenous drug abuse. Radiology 1989; 173:27-31 Bazin C, Hazera P, Greder A, Cren P, Lechevalier B, Gallet E, eta!. Pneumocystoses extrapulmonaires et disseminees au cours de !'infection par le VIH. Presse Med 1993; 22:161-65 Boutin C. La symphyse pleurale par talcage sous thoracoscopie. Editorial. Rev Mal Respir 1989; 6:91-3 Tunon-de-Lara JM, Constans J, Vincent MP, Receveur MC, Conri C, Taytard A. Spontaneous pneumothorax associated with Pneumocystis carinii pneumonia: successful treatment with talc pleurodesis. Chest 1992; 101:1177-78

Cine-Magnetic Resonance Imaging of Cor Triatriatum* Ichiro Sakamoto, M.D.; Naofumi Matsunaga, M.D.; Kuniaki Hayashi , M.D .; Yoji Ogawa, M.D.; and fun Fukui, M.D.

REFERENCES

1 Truitt T, Bagheri K, Safirstein BH. Spontaneous pneumothorax in pneumocystis carinii pneumonia. AJR 1992; 158:916-17 2 Melton LJ III, Hepper NG, Offord KP. Incidence of spontaneous pneumothorax in Olmsted County Minnesota: 1950-1974. Am Rev Respir Dis 1979; 120:1379-82 3 Crawford BK, Galloway AC, Boyd AD, Spencer FC. Treatment of AIDS-related bronchopleural fistula by pleurectomy. Ann Thorac Surg 1992; 54:212-14 4 Renzi PM, Corbeil C, Chasse M, Braidy J, Matar N. Bilateral pneumothoraces hasten mortality in AIDS patients receiving secondary prophylaxis with aerosolized pentamidine: association with a lower DCO prior to receiving aerosolized pentamidine. Chest 1992; 102:491-96 5 Wait MA, Estrera A. Changing clinical spectrum of spontaneous pneumothorax. Am J Surg 1992; 164:528-31 6 Sepkowitz KA, Telzak EE, Gold JWM, Bernard EM, Blum S, Carrow M, eta!. Pneumothorax in AIDS. Ann Intern Med 1991; 114:455-59 7 Gerein AN, Brumwell ML, Lawson LM, Chan NH, Montaner JSG. Surgical management of pneumothorax in patients with acquired immunodeficiency syndrome. Arch Surg 1991; 126:1272-77 8 DeLorenzo LJ, Huang CT, Maguire GP, Stone DJ. Roentgenographic patterns of Pneumocystis carinii pneumonia in 104 patients with AIDS. Chest 1987; 91:323-27 9 Goodman PC, Daley C, Minagi H . Spontaneous pneumothorax in AIDS patients with Pneumocystis carinii pneumonia. AJR 1986; 147:29-31 10 Sherman M, Levin D, Breidbart D. Pneumocystis carinii pneumonia with spontaneous pneumothorax: a report of three cases. Chest 1986; 90:609-10

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Two adult patients with cor triatriatum, which was shown by echocardiography and magnetic resonance imaging (MRI) using both spin-echo and cine-MR techniques, are presented. Spin-echo MRI clearly demonstrated an anatomical relationship between the membrane and pulmonary veins or left atrial appendage, which was not clear on transthoracic echocardiography. In addition, cine-MRI depicted abnormal flow through the fenestration of the anomalous membrane (case 1 and 2) and shunted flow through the associated atrial septal (Chest 1994; 106:1586-89) defect (case 2). ASD=atrial septal defect; US=ultrasonography; MRI= magnetic resonance imaging

cor triatriatum is an uncommon congenital cardiac malformation in which the left atrium is subdivided into two chambers by an anomalous membrane. The common pulmonary vein persists as an accessory chamber that communicates with the true chamber connected to the left atrial appendage *From the Department of Radiology (Drs. Sakamoto, Matsunaga, Hayashi and Ogawa), Nagasaki University School of Medicine, Nagasaki, Japan; and Department of Internal Medicine (Dr. Fukui), Sasebo General Municipal Hospital, Sasebo, Japan. Reprint requests: Dr. Sakamoto, Dept. of Radiology, Nagasaki University School of Medicine , 1-7-1 Sakamoto, Nagasaki 85Z, japan Cine-MAl of Cor Triatriatum (Sakamoto et alj

FIGURE l. A 25-year-old man with cor triatriatum. Axial cine-MRis showing the fenestration (curved arrows) of the membrane and the blood flow through the fenestration as a signal void (arrows) during the diastolic phase.

and the mitral valve. Communication between the two chambers is accomplished by one or more fenestrations in the membrane, which produces ventricular inflow obstruction similar to that in mitral stenosis. Although spin-echo magnetic resonance imaging (MRI) provides excellent preoperative delineation of the anomalous membrane, 1•2 the usefulness of cineMRI in depicting the hemodynamics of the blood flow through the fenestration in the membrane has not been reported to our knowledge. We present two cases of cor triatriatum in which surgery was performed, and emphasize the usefulness of cine-MRI in the evaluation of the anatomy and hemodynamics of cor triatriatum. CASE REPORTS CASE

1

A 25-year-old man was admitted to the hospital because of exertional dyspnea. At the time of physical examination, heart sounds were normal and no cardiac murmur was heard. A chest radiograph showed pulmonary venous congestion . Transthoracic ultrasonography (US) demonstrated an anomalous membrane in the left atrium. However, the anatomical relationship between the membrane and pulmonary veins or left atrial appendage was not clear. On transthoracic color Doppler US, abnormal flow was observed in the chamber anterior to the membrane (true chamber), but the fenestration of the membrane was not detected. The patient was examined with MRI on a 1.5-T superconducting system (Signa; GE Medical Systems, Milwaukee). On spin-echo imaging, the membrane in the left atrium and flow-related hyperintensity area in the chamber posterior to the membrane (accessory chamber) were observed. Pulmonary veins were connected

to the accessory chamber and the left atrial appendage was connected to the true chamber. On cine-MRI, signal void was observed in the left atr ium through the fenestration of the membrane, which could not be detected by transthoracic color Doppler flow imaging or spin-echo MRI (Fig 1). The blood flow was noted as a jet stream along the left atrial and ventricular septa in the early diastolic phase and changed direction in the late diastolic phase, turning back to the closed mitral leaflet. No other cardiac abnormalities were found. At surgery, the presence of an anomalous membrane with a 1-cm fenestration was confirmed in the left atrium. CASE

2

A 26-year-old man was admitted to the hospital because of exertional dyspnea and fatigue. Physical examination revealed no significant findings. No cardiac murmur was heard. Transthoracic US demonstrated an anomalous membrane in the left atrium and an atrial septal defect (ASD). On transthoracic color Doppler US, abnormal flow in the true chamber and shunted flow through the ASD were observed. However, the anatomical relationship between the membrane and the pulmonary veins or the left atrial appendage was not clear, and the fenestration of the membrane could not be detected with US alone. The MRI of the heart was obtained using spin-echo and cine-MR techniques. Spin-echo MRI clearly depicted the membrane in the left atrium and revealed that the pulmonary veins were connected to the accessory chamber and that the left atrial appendage was connected to the true chamber. In addition, cine-MRI depicted not only the signal void through the fenestration of the anomalous membrane, but also shunted flow through the associated ASD (Fig 2). At surgery, an anomalous membrane with a 1.5-cm fenestration and 2-cm ASD were confirmed. DISCUSSIO

Clinical manifestation of cor triatriatum depends on the size of the fenestration in the anomalous membrane, the CHEST / 106 / 5 / NOVEMBER, 1994

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2. A 32-year-old man with cor triatriatum and ASD. Cine-MRis showing the signal void (arrows) through the fenestration of the anomalous membrane (curved arrows), in addition to the shunted flow (open arrows) to the right atrium through the associated ASD. FJGUI\E

existence of anomalous pulmonary venous drainage and other associated anomalies. Depending on the degree of disturbance of the pulmonary venous return, the lesion might go undetected until adulthooda With the use of transthoracic US, the anomalous membrane was not always detected, and even if visualized, the whole structure could not be delineated because of limited acoustic windows and ultrasonic artifacts. This was partly overcome by the newly developed transesophageal US.4- 7 On transesophageal US, however, the posterior portion of the left atrium close to the transducer can be missed because of the lack of spatial resolution in the near field of the transducer 7 Differential diagnoses on the basis of US results include mitral stenosis, dilatation of the coronary sinus associated with the anomalous pulmonary venous return or persistent left superior vena cava, especially supravalvular mitral ring.4- 6 Supravulvular mitral ring can be anatomically distinguished from cor triatriatum by its location below the left atrial appendage. The MRI with spin-echo technique is effective for visualization of anatomic abnormalities in congenital heart disease. There have been two reports concerning the usefulness of spin-echo images in the evaluation of cor triatriatum. 1•2 In these reports, although the abnormal membrane was clearly visualized on spin-echo MRI, the fenestration of the anomalous membrane could not be detected with spin-echo technique. Cine-MRI, with a new pulse sequence, has been recently used to evaluate dynamic cardiac function and hemodynamics in congenital and acquired heart diseases. 8 High velocity flow and turbulent flow can be observed as low-signal intensity contrasted against a background of high-signal intensity representing normal blood flow. In our two cases, while nei1588

ther transthoracic US nor MRI with spin-echo technique could show the fenestration, cine-MRI clearly depicted the fenestration and abnormal flow through the fenestration as low-signal intensity. The inherent limitations of this new technique include limited in-plane spatial resolution, partial volume artifacts, and poor data acquisition due to cardiac arrythmias. Also, the images are not available in real time. Despite these limitations, cine-MRI, like standard spin-echo MRI, is able to scan all of the left atrium without hindrance from anatomic obstacles, and it is suited for assessing the hemodynamics of this disease. Whenever left ventricular inflow obstruction is suspected from clinical findings and transthoracic echocardiographic studies are not diagnostic, MRis should be obtained. We believe that a combination of spin-echo and cine-MRI obviate the need for cardiac catheterization. REFERE 1CES

1 Rumancik WM, Schulman MH, Rutkowski MM. Magnetic resonance imaging of cor triatriatum. Pediatr Cardiol 1988; 9:149-51 2 Bisset GS, Kirks DR, Strife JL, Schwartz DC. Cor triatriatum: diagnosis by MR Imaging. Am J Radiol1987; 149:567-568 3 Marin-Garcia J, Tandon R, Lucas RV , Edwards JE. Cor triatriatum : study of 20 cases. Am J Cardiol1975; 35:59-66 4 Ostman-Smith I, Silverman NH, Oldershaw P, Lincoln C. Cor triatriatum sinistrum: diagnostic features on cross-sectional echocardiography. Br Heart J 1984; 51 :211-19 5 Jacobstein MD, Hilschfeld SS. Concealed left atrial membrane: pitfalls in the diagnosis of cor triatriatum and supra valve mitral ring. Am J Cardiol1982; 49:780-786 6 Glaser J, Goren A, Ilan M, Vidne B. Cor triatriatum sinistrum: Cine-MRI of Cor Triatriatum (Sakamato eta/)

diagnosis by Doppler echocardiography. Cardiology 1990; 77:472-76 7 Schluter M, Langenstein BA, Thier W. Transesophageal twodimensional echocardiography in the diagnosis of cor triatriatum in the adult. J Am Coli Cardio\1983; 2:1011-1015 8 Sechtem U, Pflugfelder PW, Gould RG, Holt W , Lipton MJ, Higgins CB. Cine MR imaging: potential for the evaluation of cardiovascular function. Am J Radio! 1987; 148:239-246

Tracheobronchomegaly* Marlene Schwartz, M.D.; and Leonard Rossoff, M.D.

We report two cases of tracheobronchomegaly with differing presentations. The radiologic, fiberoptic bronchoscopic, and clinical findings as well as management of this rare condition are reviewed. (Chest 1994; 106:1589-90) CT=computed tomography; TBM=tracheobronchomegaly FIGURE l. The PA view of the trachea on the x-ray reveals severe dilatation of the trachea.

(TBM) or the Mounier-Kuhn T racheobronchomegaly syndrome is a rare condition characterized by marked

dilatation of the trachea and major bronchi and chronic respiratory infections. We report an additional two cases with differing clinical presentations. CASE REPORTS

CASE 1 A 71-year-old man with a 30-pack-year history of cigarette smoking, long-standing bronchiectasis, and rec urrent pneumonias presented with respiratory failure requiring mechanical ventilation. Fiberoptic bronchoscopy, for unresolving infiltrates, revealed copious thick secretions and markedly enlarged airways. The tracheobronchial mucosa was edematous and corrugated with multiple redundant folds, crypts, and diverticula. He was successfully extubated but has required continuous home oxygen, frequent antibiotics, and vigorous postural drainage. Postextubation chest radiograph (Fig 1) clearly shows the findings of TBM.

DISCUSSION

Marked tracheobronchial dilatation in association with lower respiratory tract infections was first reported by Mounier-Kuhn in 1932. A review of the world literature to 1988 by Shin et ail revealed only 82 cases. The identification of some patients with minimal or no symptoms suggests the syndrome's incidence may be greater than suspected. The radiologic diagnosis of TBM requires recognition of normal airway diameters but potential variability of magnification have led to disagreement. 2 Himalstein and Gallagher3 measured the diameters of the tracheal and mainstem bronchial lumens at autopsy in 100 men with no

CASE 2 A 61-year-old man, 30-pack-year smoker with mild ankylosing spondylitis presented with 1 month of progressive exertional dyspnea and cough productive of mucopurulent sputum. He denied all constitutional complaints. Initial roentgenogram showed bilateral lower lobe infiltrates and pleural thickening. Despite two weeks of outpatient antibiotics, the infiltrates progressed and failed to resolve with an additional week of inpatient intravenous antibiotics. All sputum smears, cultures, and cytology were negative. Bronchoscopy results suggested submucosal atrophy and chondromalacia of the trachea and major bronchi. Computed tomography (CT) scan of the chest (Fig 2) revealed paraseptal, panlobular, and centrilobular emphysema, extensive bronchiectasis, interstitial fibrosis of the lower lobes, and chronic pleural thickening. Enlargement of the trachea and major bronchi was also noted. *From the Division of Pulmonary / Critical Care, Long Island Jewish Medical Center, The Long Island Campus for the Albert Einstein College of Medicine, New Hyde Park, New York.

FIGURE 2. The CT scan of the chest at the level of the carina reveals bronchial dilatation, bronchiectasis, and emphysematous changes. CHEST / 106 / 5 / NOVEMBER, 1994

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