Radionuclide in Pulmonary Sequestration

Yasuhiko Kobayashi, Toshihiro Abe, Akitoshi Sato, Kanji Nagai, Yoshikazu Nagai, and Chihanu Ibukiyama

Tokyo Medical College, Shinjuku-ku, Tokyo, Japan

Wereporta casediagnosedaspulmonarysequestrationbyredionucildeangIo@aphyprior to operationwhichshowedanomalousarteries.Redionuclideangiographycleaiiyrevealed the conditionof boththe pulmonaryarteryandaorta,andis consideredto be extremely useful in the diagnosis of pulmonary sequestration. It will probably be applied to more patientsin the future.

II Nuci Med 26:1035—1038, 1985

ubmonary sequestration is a condition involving ab great was performed. A bolus injection of 10 mCi Tc normal intra or extrabobar pulmonary tissue supplied 99mpertechnetatewasperformedintothe cubitalvein. A40° by systemic circulation (i.e., a pulmonary malforma left anterior oblique image was performed with a gamma tion characterized by the presence of abnormal blood camera equipped with parallel-type multipurpose collimator' at a speed of 1 frame/sec. The pulmonary arterial phase vessels). This disorder can be misdiagnosed as pulmo showed a shadow defect in the posterior tower left lung, nary cyst or tumor on the basis of various clinical suggesting a mass not perfused by the pulmonary (Fig. observations, and, as a result, severe bleeding from an 3 top). Furthermore, the aortic phase revealed abnormal anomalous blood vessel during surgery has been report bloodvesselsdrawntowardsthe mass(Fig. 3bottom).Conse ed (1). It is therefore important to examine the possibib quently, the mass was concluded to be pulmonary sequestra ity of pulmonary sequestration by preoperative antenio tion supplied by the thoracic . Operative findings con graphy that can demonstrate the presence of an cluded that the mass was easily separated from normal lung anomalous artery. Since this disorder is often found in tissues. A total of three abnormal arteries (one 7 mm in pediatric cases, general anesthesia is frequently needed diameter, and the others 3 mm each) from the thoracic aorta for angiognaphy. On the other hand, radionuclide an and a returning to the pulmonary vein were found. giography is a convenient noninvasive method to exam Resected specimen indicated that the pleura covering the mass was not connected with that covering the normal lung. inc vascular distribution in various disorders. We report Therefore, a diagnosis of extratobar pulmonary sequestration a case in which imaging of an was made. anomalous artery yielded a preoperative diagnosis of pulmonary sequestration. DISCUSSION CASE REPORT In 1777, HUber reported abnormal lung tissue fed by A 7-yr-oldmale presentedwith feverand cough.Chest x an anomalous artery deriving from the aorta at autop ray examination showed a uniform density shadow with a sy. Thereafter, in 1946, Pryce named the disorder pul distinct border in the posteroinferior left lung region (510) monary sequestration (2—3).He also classified the se (Fig. 1). Computed (CT) revealed a mass with a questration into intrabobar sequestration (ILS) and uniform density adjacent to the thoracic descending aorta in the posterior lower left lung (Fig. 2). From his history and extrabobar sequestration (ELS) depending on whether laboratory test results, pulmonary sequestration was suspect or not the abnormal lung tissue had pleura in common ed, and radionuclide angiography of the cardiopulmonary with normal lung tissue. Currently, various hypothesis have been presented for the mechanism of abnormal formation. Among those presented, Pryce's traction Received Jan. 17, 1985; revision accepted June 6, 1985. For reprints contact: Yasuhiko Kobayashi, 2nd Dept. of Internal theory (2—3)is widely accepted. The theory contends Medicine, Tokyo Medical College, 6-7-1, Nishishinjuku, Shinjuku that an anomalous artery enters the rudimentary lung, ku,Tokyo 160,Japan. and sequestration results from separation ofa tip of the

Volume26 •Number9 •September1985 1035 —@-lP@, p .@ FIGURE1 Chest x-ray shows uniform shadow with distinct boundary in posteroinferior left lung region (left: left lateral; right: anterior)

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FIGURE2 X-ray CT shows mass with uniform density adjacent to thoracic descendingaorta in rear of lower left lung

1036 Kobayashi,Abe, Sato et al TheJournalof NuclearMedicine PA phase

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FIGURE3 Radionuclideangiogram taken at speed of 1 frame/sec. Pulmonaryarterial phase shows shadow defect (upper figure, indicated by arrows) in posterior lower left lung. Aortic phase shows anomalous artery and mass at same area

embryonic bronchial tree. This action is attributed to aorta, not by the . There are, however, traction caused by the adventitious blood supply. The few reports on the subject (10—11). anomalous artery usually originates from the thoracic In conclusion, the case reported here was first sus and abdominal aorta (4). The venous drainage is usual pected to be a mediastinal tumor, but was finally diag by to the pulmonary vein in ILS, and in ELS to the nosed as pulmonary sequestration based on the obser azygos, hemiazygos, or portal vein (5). vation ofa defect lesion in the pulmonary arterial phase For the diagnosis of this disorder, it is important to and abnormal artery and blood distribution to the be demonstrate an anomalous artery. Though this can be sion in the aortic phase. Although the effectiveness of confirmed by arteriography using contrast medium, the radionuclide angiography as a diagnostic procedure procedure cannot be readily performed on children may be affected by the characteristics ofthe sequestrat because it often requires general anesthesia. The recent ed lung or the diameter of the abnormal artery, it was development of noninvasive examination techniques concluded to have been useful and convenient for the makes it possible to show an anomalous artery by x-ray diagnosis of pulmonary sequestration. CTonultrasound(6—8).Theradionuclidevenography devised by Rosenthall in 1966 (9) has been applied to FOOTNOTE examination of the vascular system. Because of its con venience, it is now widely used for the diagnosis of * ZLC 3700, Siemens Medical Systems, Inc., lselin, Ni conditions affecting the cardio-pulmonary vasculatune. Radionuclide angiognaphy can provide images of both pulmonary arterial and aontic phases by a single injec ACKNOWLEDGEMENT tion into the cubital vein. Therefore, radionuclide an The authors wishto thank Assoc.Prof. J. Patrick Barron, giognaphy can be considered useful in the diagnosis of St. Marianna University School of Medicine, for revising the pulmonary sequestration supplied with blood by the manuscript.

Volume26 •Number9 •September1985 1037 REFERENCES tion: Ultrasonic appearance. I C/in Ultrasound 10:294- 296, 1982 7. Baker EL, Gore RM, Moss AA: Retroperitoneal pul I. Okubo 5, Ogawa i: A case of cystic disease of the lung monary sequestration computed tomographic findings. combined with abnormal artery. Kyobu Geka (Jpn J AIR 138:956-957, 1982 ThoracSurg)7:393-396,1954 8. Miller PA, Williamson BRJ, Minor GR, et al: Pulmo 2. Pryce DM: Lower accessory pulmonary artery with nary sequestration: Visualization of the feeding artery intralobar sequestration oflung: A report ofseven cases. by CT. I Comput Assist Tomogr 6:828-830, 1982 J Path Bact 58:457-467, 1946 9. Rosenthall L: Radionuclide using techne 3. Pryce DM, Sellors TH, Blair LG: Intralobar sequestra tium-99m pertechnetate and the gamma-ray scintilla tion of lung associated with an abnormal pulmonary tion camera. AIR 97:874-879, 1966 artery. Brit JSurg 35:18-29, 1947 10. Kawakami K, Tada 5, Katsuyama N: Radionuclide 4. Khalil KG, Kilman iW: Pulmonary sequestration. I study in pulmonary sequestration. I Nuc/ Med 19:287- Thorac Cardiovasc Surg 70:928-937, 1975 289, 1978 5. Carter R: Pulmonary sequestration. Ann Thorac Surg 11. Gooneratne N, Conway JJ: Radionuclide angiographic 7:68-88,1969 diagnosis of bronchopulmonary sequestration. I Nuc/ 6. iaffe MH, Bank ER, Silver TM: Pulmonary sequestra Med 17:1035-1037,1976

1038 Kobayashi,Abe, Sato et al TheJournalof NuclearMedicine