Most patients with nontraumatic chylothoraces or chylothoraces of unknown etiologies present with acute respiratory illness (ARI), which consists of 1 or more of the following: cough, sputum production, chest pain, or dyspnea (with or without fever). The evaluation of ARI has been addressed by the American College of Radiology (ACR), and the imaging evaluation includes chest radiography and chest CT [50,51]. The consistent finding of chylothorax on initial imaging is the presence of a pleural effusion, which is a common medical problem with more than 50 recognized causes [52]. Pleural fluid studies are necessary for definitive diagnosis and to narrow the cause etiology of chylothorax. Ultrasound US reliably detects pleural fluid but cannot definitively discriminate between the types of pleural effusion and provides minimal additional information to narrow the differential diagnosis [20]. US can be helpful in the guidance of thoracentesis and intranodal injection during lymphangiography [21]. Conventional lymphangiography Conventional lymphangiography is the gold standard for visualization of lymph nodes, lymphatic vessels, cisterna chyli, and the thoracic duct and for detection of lymphatic leakage [14,22,23]. In a nontraumatic or idiopathic chylothorax, conventional lymphangiography may help diagnose lymphatic vessel diseases and anatomic abnormalities and prevent unnecessary procedures. However, compared with traumatic chylothorax and particularly in the setting of a systemic disease, conventional lymphangiography does not always elucidate the underlying etiology. Additionally, TDE is less clinically effective in a nontraumatic chylothorax unless thoracic duct occlusion or extravasation is present [6]. Nuclear lymphoscintigraphy Nuclear lymphoscintigraphy has only a few reports that suggest it may be able to localize the site of chylous leak, particularly if used with 3-D single-photon emission CT/CT techniques [31-33].
Chylothorax Treatment Planning. Most patients with nontraumatic chylothoraces or chylothoraces of unknown etiologies present with acute respiratory illness (ARI), which consists of 1 or more of the following: cough, sputum production, chest pain, or dyspnea (with or without fever). The evaluation of ARI has been addressed by the American College of Radiology (ACR), and the imaging evaluation includes chest radiography and chest CT [50,51]. The consistent finding of chylothorax on initial imaging is the presence of a pleural effusion, which is a common medical problem with more than 50 recognized causes [52]. Pleural fluid studies are necessary for definitive diagnosis and to narrow the cause etiology of chylothorax. Ultrasound US reliably detects pleural fluid but cannot definitively discriminate between the types of pleural effusion and provides minimal additional information to narrow the differential diagnosis [20]. US can be helpful in the guidance of thoracentesis and intranodal injection during lymphangiography [21]. Conventional lymphangiography Conventional lymphangiography is the gold standard for visualization of lymph nodes, lymphatic vessels, cisterna chyli, and the thoracic duct and for detection of lymphatic leakage [14,22,23]. In a nontraumatic or idiopathic chylothorax, conventional lymphangiography may help diagnose lymphatic vessel diseases and anatomic abnormalities and prevent unnecessary procedures. However, compared with traumatic chylothorax and particularly in the setting of a systemic disease, conventional lymphangiography does not always elucidate the underlying etiology. Additionally, TDE is less clinically effective in a nontraumatic chylothorax unless thoracic duct occlusion or extravasation is present [6]. Nuclear lymphoscintigraphy Nuclear lymphoscintigraphy has only a few reports that suggest it may be able to localize the site of chylous leak, particularly if used with 3-D single-photon emission CT/CT techniques [31-33].