Pediatric Pulmonology 49:E126–E129 (2014)
Successful Endovascular Treatment of Bilateral Intralobar Pulmonary Sequestration With a Bridging Isthmus in a Child Su Joa Ahn, MD,1 Eun Young Kim, MD,1* Jeong Ho Kim, MD,1 Sung Su Byun, Hyung Sik Kim, MD,1 Hye-Young Choi, MD,1 and Yong Han Sun, MD2
MD,
1
Summary. Pulmonary sequestration refers to aberrant formation of segmental lung tissue that has no connection with the bronchial tree and receives a blood supply from a systemic artery. Bilateral pulmonary sequestration, especially with a bridging isthmus is extremely rare. Although endovascular treatment is regarded as the less invasive alternative for the treatment of pulmonary sequestration, all previously reported bilateral pulmonary sequestrations have been treated surgically. We report the case of a 13-year-old girl who underwent successful endovascular treatment for bilateral pulmonary sequestration with a bridging isthmus. Thoracic CT angiography showed a heterogeneous mass-like consolidation in the both lower lobes connected each other via a bridging isthmus behind the heart. CTalso demonstrated an aberrant artery, which originated from the celiac trunk, supplied the sequestration of the left lower lobe, and that a branch from the aberrant artery traversed to the sequestration in the right lower lobe. After percutaneous endovascular embolization using microcoils and gelfoam, the patient had no complications and the bilateral sequestration showed markedly decrease in the size. Pediatr Pulmonol. 2014; 49: E126–E129. ß 2014 Wiley Periodicals, Inc. Key words: bilateral; bronchopulmonary sequestration; lung malformation; CT angiography; endovascular treatment. Funding source: none reported
INTRODUCTION
Pulmonary sequestration is a malformation in which a portion of lung is detached from the remaining normal lung and receives a blood supply from a systemic artery. Bilateral pulmonary sequestration, especially with a bridging isthmus is rare.1–2 Furthermore, all reported bilateral pulmonary sequestrations were treated surgically. We report the case of a 13-year-old girl who underwent successful endovascular treatment for bilateral pulmonary sequestration with a bridging isthmus. PATIENT PRESENTATION
A13-year-old girl with a 7-month history of recurrent cough was referred to our hospital for further evaluation. 1 Department of Radiology, Gachon University Gil Hospital, Incheon, Republic of Korea.
Chest radiography visualized a 6 cm sized mass-like consolidation in left lower lung zone (Fig. 1). Ultrasonography (Acuson Sequoia 512 Ultrasound, Siemens Medical Solutions, Forchheim, Germany) showed an echogenic mass with small cystic components in left lower lobe, and color Doppler images revealed a systemic arterial supply from the abdominal aorta, compatible with pulmonary sequestration (Fig. 2). To accurately determine the type of pulmonary sequestration (intra- or extralobar type) and the course of the feeding artery, thoracic CT angiography was performed using a multidetector CT scanner (Somatom Sensation 16 scanner, Siemens Medical Solutions) after intravenously injecting 100 ml (3 ml/sec) of nonionic contrast medium (Iopamiron 300; Bracco, Milan, Italy). CT images revealed a heterogeneous mass-like
Correspondence to: Eun Young Kim, MD, Department of Radiology, Gachon University Gil Hospital, 1198, Guwol-dong, Namdong-gu, Incheon 405-760, Republic of Korea. E-mail: [email protected]
2
Department of Pediatrics, Gachon University Gil Hospital, Incheon, Republic of Korea. Conflict of interest: None.
ß 2014 Wiley Periodicals, Inc.
Received 14 March 2013; Accepted 29 June 2013. DOI 10.1002/ppul.22879 Published online 5 February 2014 in Wiley Online Library (wileyonlinelibrary.com).
Embolization in Bilateral Pulmonary Sequestration
E127
Fig. 1. Chest radiograph showing a mass-like consolidation in the left lower lobe.
consolidation in the paravertebral region of the left lower lobe connected to mild consolidation in the right lower lobe via a bridging isthmus behind the heart (Fig. 3). CT obtained during arterial phase showed that an aberrant artery, which originated from the celiac trunk, supplied the sequestration of the left lower lobe, and that a branch from the aberrant artery traversed to the sequestration in the right lower lobe. Venous drainage was into the left atrium via bilateral inferior pulmonary veins. These findings were compatible with bilateral intralobar pulmonary sequestration with a bridging isthmus. Since the young girl patient declined thoracic surgery with the concern of post-operative scar, percutaneous endovascular embolization was requested to treat the bilateral intralobar pulmonary sequestration. Before the procedure, intravenous ketamine (1 mg/kg) and a continuous intravenous infusion of midazolam (0.5 g/kg/min) were administered for general anesthesia. Additionally, the patient received 100 U/kg of heparin and 25 mg/kg of cefazolin intravenously. After catheterization through right femoral artery using a 5-F sheath (Cook, Bloomington, IN), aortogram showed an aberrant systemic artery supplying sequestrations of both lower lobes (Fig. 4A), which was identical finding to that of CT angiography. Endovascular treatment was performed by a general interventional radiologist. Through a coaxially inserted 3-F microcatheter, gelatin sponge particles (approximately 1 mm3, Spongostan; Johnson & Johnson Medical, Gargrave, UK) and a total of eleven microcoils (2–3-mm diameter, 2–4-cm length; Cook) were used to occlude the feeding artery about 1 cm before the bifurcation (Fig. 4). An aortogram obtained immediately after embolization confirmed absence of blood flow to the
Fig. 2. Ultrasonogram of the left lower chest. A: Grayscale US image showing an echogenic triangular lesion with hypoechoic cystic changes (arrows). D, diaphragm. B: Longitudinal color Doppler US image showing a large tortuous vessel with high velocity flow in the direction of the probe. L, liver.
bilateral sequestration (Fig. 4B). Total procedure time from initial aortogram to embolization therapy was approximately 20 min. The patient recovered well and was discharged without any complication. Follow-up CT scans obtained 1 month after endovascular treatment showed partial regression of the lesion in bilateral lower lobes, and a final CT scan conducted 1 year after the procedure showed minimally residual cystic lesions in the left lower lobe (Fig. 5). DISCUSSION
Pulmonary sequestration is a rare congenital malformation that represents 0.15–6.4% of all pulmonary malformations.3–4 Pulmonary sequestration is a condition, whereby nonfunctioning bronchopulmonary tissue separated from the tracheobronchial tree receives arterial Pediatric Pulmonology
E128
Ahn et al.
Fig. 3. A: CT scan revealing a localized area of abnormal lung in the posteromedial region of the left lung and showing connection to mild consolidation of the right lower lobe with a midline bridging isthmus (arrows) behind the heart. B,C: Coronal volume-rendered images demonstrate an aberrant artery (arrow) originating from the celiac trunk supplying the sequestration in the left lower lobe. A small branch of the aberrant artery (arrowhead) also supplied the sequestration in the right lower lobe.
blood from the systemic circulation. Aberrant systemic arteries may be single or multiple. Two types have been described according to their relationships with the remaining normal lung. Intralobar sequestration occurs in normal lung parenchyma and its venous drainage is toward the normal pulmonary veins. On the other hand, extralobar sequestration is completely enclosed by a pleural membrane and derives its arterial supply from the aorta or one of its branches and drains via systemic veins.5 Bilateral pulmonary sequestration is rare6–9 and the presence of a bridging isthmus between bilateral pulmonary sequestrations is extremely rare. Bilateral pulmonary sequestration is similar to “horseshoe lung,”1–2 which is a rare congenital malformation in which an isthmus of pulmonary parenchyma extends from the right lung base across the midline behind the heart and fuses with the base of the left lung. Arterial supply to the isthmic portion of the horseshoe lung is almost always via branches of the pulmonary artery and in most reported cases, horseshoe lung has been associated with a certain degree of pulmonary hypoplasia.10–11 Although endovascular treatment is regarded as the less invasive alternative, all previously reported bilateral Pediatric Pulmonology
Fig. 4. A: Aortogram showing an aberrant systemic artery supplying sequestrations of both lower lobes (arrows). B: Aortogram obtained immediately after embolization demonstrating no flow to the bilateral sequestration.
pulmonary sequestrations have been treated surgically (bilateral thoracotomy or unilateral thoracotomy with contralateral feeding artery ligation).1,2,6,9 Long-term follow-up studies of children treated surgically for pulmonary sequestration have reported complications of pneumonia, asthma, gastroesophageal reflux, pectus excavatum, and pyloric stenosis.12 Although reported complications of endovascular treatment of pulmonary sequestration includes transient
Embolization in Bilateral Pulmonary Sequestration
E129
such as last image hold, electronic collimation, pulsed intermittent fluoroscopy and avoidance of magnification can be used.15 Our experience of this case shows that in the rare case of bilateral pulmonary sequestration with a bridging isthmus, endovascular treatment provides a good noninvasive alternative and satisfactory clinical results. REFERENCES
Fig. 5. A: Follow-up CT images obtained 1 month after endovascular treatment showing partial regression of the lesion in bilateral lower lobes. B: CT image obtained 1 year after the procedure revealing minimal residual cystic lesions (arrows) in the left lower lobe.
limb ischemia, fever, femoral artery thrombosis at puncture site and inadvertent embolization of the pulmonary arteries or aorta,13 no complication occurred over 1 year of follow-up after the procedure in our patient. A reported limitation of endovascular treatment of pulmonary sequestration is incomplete treatment requiring repeat embolization.14 According to the previous report by Chien et al., four of six patients were cured after the first embolization and the remaining two patients were cured by re-embolization after incomplete initial embolization. Another limitation of endovascular treatment is irradiation. To decrease radiation dose, several techniques
1. Cerruti MM, Marmolejos F, Cacciarelli T. Bilateral intralobar pulmonary sequestration with horseshoe lung. Ann Thorac Surg 1993;55:509–510. 2. Kuo R, Shih SL, Huang JK. On the AJR digital viewbox. Bilateral pulmonary sequestration with bridging isthmus in a boy with Williams syndrome. AJR Am J Roentgenol 2006;187:W133– W134. 3. Coman C, Stan A, Georgescu G, Dobrinov H, Dimitriu M. Present problems of intra- and extra-lobar pulmonary sequestration. Poumon Coeur 1973;29:211–220. 4. Savic B, Birtel FJ, Tholen W, Funke HD, Knoche R. Lung sequestration: report of seven cases and review of 540 published cases. Thorax 1979;34:96–101. 5. Sade RM, Clouse M, Ellis FH, Jr. The spectrum of pulmonary sequestration. Ann Thorac Surg 1974;18:644–658. 6. Juettner FM, Pinter HH, Lammer G, Popper H, Friehs GB. Bilateral intralobar pulmonary sequestration: therapeutic implications. Ann Thorac Surg 1987;43:660–662. 7. Pan G, Singleton E, Nihill M, Harberg F. A case of bilateral gastric bronchopulmonary-foregut malformation. Pediatr Radiol 1989; 19:463–464. 8. Roe JP, Mack JW, Shirley JH. Bilateral pulmonary sequestrations. J Thorac Cardiovasc Surg 1980;80:8–10. 9. Stern R, Berger S, Casaulta C, Raio L, Abderhalden S, Zachariou Z. Bilateral intralobar pulmonary sequestration in a newborn, case report and review of the literature on bilateral pulmonary sequestrations. J Pediatr Surg 2007;42:E19–E23. 10. Goo HW, Kim YH, Ko JK, Park IS, Yoon CH. Horseshoe lung: useful angiographic and bronchographic images using multidetector-row spiral CT in two infants. Pediatr Radiol 2002;32: 529–532. 11. Lutterman J, Jedeikin R, Cleveland DC. Horseshoe lung with left lung hypoplasia and critical pulmonary venous stenosis. Ann Thorac Surg 2004;77:1085–1087. 12. Bratu I, Flageole H, Chen MF, Di Lorenzo M, Yazbeck S, Laberge JM. The multiple facets of pulmonary sequestration. J Pediatr Surg 2001;36:784–790. 13. Ganeshan A, Freedman J, Hoey ET, Steyn R, Henderson J, Crowe PM. Transcatheter coil embolisation: a novel definitive treatment option for intralobar pulmonary sequestration. Heart Lung Circ 2010;19:561–565. 14. Chien KJ, Huang TC, Lin CC, Lee CL, Hsieh KS, Weng KP. Early and late outcomes of coil embolization of pulmonary sequestration in children. Circ J 2009;73:938–942. 15. Miller DL, Balter S, Schueler BA, Wagner LK, Strauss KJ, Vano E. Clinical radiation management for fluoroscopically guided interventional procedures. Radiology 2010;257:321–332.
Pediatric Pulmonology
Successful Endovascular Treatment of Bilateral Intralobar Pulmonary Sequestration With a Bridging Isthmus in a Child Su Joa Ahn, MD,1 Eun Young Kim, MD,1* Jeong Ho Kim, MD,1 Sung Su Byun, Hyung Sik Kim, MD,1 Hye-Young Choi, MD,1 and Yong Han Sun, MD2
MD,
1
Summary. Pulmonary sequestration refers to aberrant formation of segmental lung tissue that has no connection with the bronchial tree and receives a blood supply from a systemic artery. Bilateral pulmonary sequestration, especially with a bridging isthmus is extremely rare. Although endovascular treatment is regarded as the less invasive alternative for the treatment of pulmonary sequestration, all previously reported bilateral pulmonary sequestrations have been treated surgically. We report the case of a 13-year-old girl who underwent successful endovascular treatment for bilateral pulmonary sequestration with a bridging isthmus. Thoracic CT angiography showed a heterogeneous mass-like consolidation in the both lower lobes connected each other via a bridging isthmus behind the heart. CTalso demonstrated an aberrant artery, which originated from the celiac trunk, supplied the sequestration of the left lower lobe, and that a branch from the aberrant artery traversed to the sequestration in the right lower lobe. After percutaneous endovascular embolization using microcoils and gelfoam, the patient had no complications and the bilateral sequestration showed markedly decrease in the size. Pediatr Pulmonol. 2014; 49: E126–E129. ß 2014 Wiley Periodicals, Inc. Key words: bilateral; bronchopulmonary sequestration; lung malformation; CT angiography; endovascular treatment. Funding source: none reported
INTRODUCTION
Pulmonary sequestration is a malformation in which a portion of lung is detached from the remaining normal lung and receives a blood supply from a systemic artery. Bilateral pulmonary sequestration, especially with a bridging isthmus is rare.1–2 Furthermore, all reported bilateral pulmonary sequestrations were treated surgically. We report the case of a 13-year-old girl who underwent successful endovascular treatment for bilateral pulmonary sequestration with a bridging isthmus. PATIENT PRESENTATION
A13-year-old girl with a 7-month history of recurrent cough was referred to our hospital for further evaluation. 1 Department of Radiology, Gachon University Gil Hospital, Incheon, Republic of Korea.
Chest radiography visualized a 6 cm sized mass-like consolidation in left lower lung zone (Fig. 1). Ultrasonography (Acuson Sequoia 512 Ultrasound, Siemens Medical Solutions, Forchheim, Germany) showed an echogenic mass with small cystic components in left lower lobe, and color Doppler images revealed a systemic arterial supply from the abdominal aorta, compatible with pulmonary sequestration (Fig. 2). To accurately determine the type of pulmonary sequestration (intra- or extralobar type) and the course of the feeding artery, thoracic CT angiography was performed using a multidetector CT scanner (Somatom Sensation 16 scanner, Siemens Medical Solutions) after intravenously injecting 100 ml (3 ml/sec) of nonionic contrast medium (Iopamiron 300; Bracco, Milan, Italy). CT images revealed a heterogeneous mass-like
Correspondence to: Eun Young Kim, MD, Department of Radiology, Gachon University Gil Hospital, 1198, Guwol-dong, Namdong-gu, Incheon 405-760, Republic of Korea. E-mail: [email protected]
2
Department of Pediatrics, Gachon University Gil Hospital, Incheon, Republic of Korea. Conflict of interest: None.
ß 2014 Wiley Periodicals, Inc.
Received 14 March 2013; Accepted 29 June 2013. DOI 10.1002/ppul.22879 Published online 5 February 2014 in Wiley Online Library (wileyonlinelibrary.com).
Embolization in Bilateral Pulmonary Sequestration
E127
Fig. 1. Chest radiograph showing a mass-like consolidation in the left lower lobe.
consolidation in the paravertebral region of the left lower lobe connected to mild consolidation in the right lower lobe via a bridging isthmus behind the heart (Fig. 3). CT obtained during arterial phase showed that an aberrant artery, which originated from the celiac trunk, supplied the sequestration of the left lower lobe, and that a branch from the aberrant artery traversed to the sequestration in the right lower lobe. Venous drainage was into the left atrium via bilateral inferior pulmonary veins. These findings were compatible with bilateral intralobar pulmonary sequestration with a bridging isthmus. Since the young girl patient declined thoracic surgery with the concern of post-operative scar, percutaneous endovascular embolization was requested to treat the bilateral intralobar pulmonary sequestration. Before the procedure, intravenous ketamine (1 mg/kg) and a continuous intravenous infusion of midazolam (0.5 g/kg/min) were administered for general anesthesia. Additionally, the patient received 100 U/kg of heparin and 25 mg/kg of cefazolin intravenously. After catheterization through right femoral artery using a 5-F sheath (Cook, Bloomington, IN), aortogram showed an aberrant systemic artery supplying sequestrations of both lower lobes (Fig. 4A), which was identical finding to that of CT angiography. Endovascular treatment was performed by a general interventional radiologist. Through a coaxially inserted 3-F microcatheter, gelatin sponge particles (approximately 1 mm3, Spongostan; Johnson & Johnson Medical, Gargrave, UK) and a total of eleven microcoils (2–3-mm diameter, 2–4-cm length; Cook) were used to occlude the feeding artery about 1 cm before the bifurcation (Fig. 4). An aortogram obtained immediately after embolization confirmed absence of blood flow to the
Fig. 2. Ultrasonogram of the left lower chest. A: Grayscale US image showing an echogenic triangular lesion with hypoechoic cystic changes (arrows). D, diaphragm. B: Longitudinal color Doppler US image showing a large tortuous vessel with high velocity flow in the direction of the probe. L, liver.
bilateral sequestration (Fig. 4B). Total procedure time from initial aortogram to embolization therapy was approximately 20 min. The patient recovered well and was discharged without any complication. Follow-up CT scans obtained 1 month after endovascular treatment showed partial regression of the lesion in bilateral lower lobes, and a final CT scan conducted 1 year after the procedure showed minimally residual cystic lesions in the left lower lobe (Fig. 5). DISCUSSION
Pulmonary sequestration is a rare congenital malformation that represents 0.15–6.4% of all pulmonary malformations.3–4 Pulmonary sequestration is a condition, whereby nonfunctioning bronchopulmonary tissue separated from the tracheobronchial tree receives arterial Pediatric Pulmonology
E128
Ahn et al.
Fig. 3. A: CT scan revealing a localized area of abnormal lung in the posteromedial region of the left lung and showing connection to mild consolidation of the right lower lobe with a midline bridging isthmus (arrows) behind the heart. B,C: Coronal volume-rendered images demonstrate an aberrant artery (arrow) originating from the celiac trunk supplying the sequestration in the left lower lobe. A small branch of the aberrant artery (arrowhead) also supplied the sequestration in the right lower lobe.
blood from the systemic circulation. Aberrant systemic arteries may be single or multiple. Two types have been described according to their relationships with the remaining normal lung. Intralobar sequestration occurs in normal lung parenchyma and its venous drainage is toward the normal pulmonary veins. On the other hand, extralobar sequestration is completely enclosed by a pleural membrane and derives its arterial supply from the aorta or one of its branches and drains via systemic veins.5 Bilateral pulmonary sequestration is rare6–9 and the presence of a bridging isthmus between bilateral pulmonary sequestrations is extremely rare. Bilateral pulmonary sequestration is similar to “horseshoe lung,”1–2 which is a rare congenital malformation in which an isthmus of pulmonary parenchyma extends from the right lung base across the midline behind the heart and fuses with the base of the left lung. Arterial supply to the isthmic portion of the horseshoe lung is almost always via branches of the pulmonary artery and in most reported cases, horseshoe lung has been associated with a certain degree of pulmonary hypoplasia.10–11 Although endovascular treatment is regarded as the less invasive alternative, all previously reported bilateral Pediatric Pulmonology
Fig. 4. A: Aortogram showing an aberrant systemic artery supplying sequestrations of both lower lobes (arrows). B: Aortogram obtained immediately after embolization demonstrating no flow to the bilateral sequestration.
pulmonary sequestrations have been treated surgically (bilateral thoracotomy or unilateral thoracotomy with contralateral feeding artery ligation).1,2,6,9 Long-term follow-up studies of children treated surgically for pulmonary sequestration have reported complications of pneumonia, asthma, gastroesophageal reflux, pectus excavatum, and pyloric stenosis.12 Although reported complications of endovascular treatment of pulmonary sequestration includes transient
Embolization in Bilateral Pulmonary Sequestration
E129
such as last image hold, electronic collimation, pulsed intermittent fluoroscopy and avoidance of magnification can be used.15 Our experience of this case shows that in the rare case of bilateral pulmonary sequestration with a bridging isthmus, endovascular treatment provides a good noninvasive alternative and satisfactory clinical results. REFERENCES
Fig. 5. A: Follow-up CT images obtained 1 month after endovascular treatment showing partial regression of the lesion in bilateral lower lobes. B: CT image obtained 1 year after the procedure revealing minimal residual cystic lesions (arrows) in the left lower lobe.
limb ischemia, fever, femoral artery thrombosis at puncture site and inadvertent embolization of the pulmonary arteries or aorta,13 no complication occurred over 1 year of follow-up after the procedure in our patient. A reported limitation of endovascular treatment of pulmonary sequestration is incomplete treatment requiring repeat embolization.14 According to the previous report by Chien et al., four of six patients were cured after the first embolization and the remaining two patients were cured by re-embolization after incomplete initial embolization. Another limitation of endovascular treatment is irradiation. To decrease radiation dose, several techniques
1. Cerruti MM, Marmolejos F, Cacciarelli T. Bilateral intralobar pulmonary sequestration with horseshoe lung. Ann Thorac Surg 1993;55:509–510. 2. Kuo R, Shih SL, Huang JK. On the AJR digital viewbox. Bilateral pulmonary sequestration with bridging isthmus in a boy with Williams syndrome. AJR Am J Roentgenol 2006;187:W133– W134. 3. Coman C, Stan A, Georgescu G, Dobrinov H, Dimitriu M. Present problems of intra- and extra-lobar pulmonary sequestration. Poumon Coeur 1973;29:211–220. 4. Savic B, Birtel FJ, Tholen W, Funke HD, Knoche R. Lung sequestration: report of seven cases and review of 540 published cases. Thorax 1979;34:96–101. 5. Sade RM, Clouse M, Ellis FH, Jr. The spectrum of pulmonary sequestration. Ann Thorac Surg 1974;18:644–658. 6. Juettner FM, Pinter HH, Lammer G, Popper H, Friehs GB. Bilateral intralobar pulmonary sequestration: therapeutic implications. Ann Thorac Surg 1987;43:660–662. 7. Pan G, Singleton E, Nihill M, Harberg F. A case of bilateral gastric bronchopulmonary-foregut malformation. Pediatr Radiol 1989; 19:463–464. 8. Roe JP, Mack JW, Shirley JH. Bilateral pulmonary sequestrations. J Thorac Cardiovasc Surg 1980;80:8–10. 9. Stern R, Berger S, Casaulta C, Raio L, Abderhalden S, Zachariou Z. Bilateral intralobar pulmonary sequestration in a newborn, case report and review of the literature on bilateral pulmonary sequestrations. J Pediatr Surg 2007;42:E19–E23. 10. Goo HW, Kim YH, Ko JK, Park IS, Yoon CH. Horseshoe lung: useful angiographic and bronchographic images using multidetector-row spiral CT in two infants. Pediatr Radiol 2002;32: 529–532. 11. Lutterman J, Jedeikin R, Cleveland DC. Horseshoe lung with left lung hypoplasia and critical pulmonary venous stenosis. Ann Thorac Surg 2004;77:1085–1087. 12. Bratu I, Flageole H, Chen MF, Di Lorenzo M, Yazbeck S, Laberge JM. The multiple facets of pulmonary sequestration. J Pediatr Surg 2001;36:784–790. 13. Ganeshan A, Freedman J, Hoey ET, Steyn R, Henderson J, Crowe PM. Transcatheter coil embolisation: a novel definitive treatment option for intralobar pulmonary sequestration. Heart Lung Circ 2010;19:561–565. 14. Chien KJ, Huang TC, Lin CC, Lee CL, Hsieh KS, Weng KP. Early and late outcomes of coil embolization of pulmonary sequestration in children. Circ J 2009;73:938–942. 15. Miller DL, Balter S, Schueler BA, Wagner LK, Strauss KJ, Vano E. Clinical radiation management for fluoroscopically guided interventional procedures. Radiology 2010;257:321–332.
Pediatric Pulmonology
