Effects of the pulmonary ligament on helical CT appearances of lower thoracic disease: anatomic-radiologic study / 中华放射学杂志

ABSTRACT

Objective To determine how the pulmonary ligament affects the helical CT appearances of the lower thoracic disease on the basis of the anatomic findings. Methods Four cadavers were cut transversely, with the section thickness of 11.3-13.4 mm. 57 patients with the lower thoracic disease were scanned using Somatom Plus 4, with administration of intravenous contrast material. The correlation of the anatomic findings of the pulmonary ligament and the helical CT appearances of the lower thoracic disease was evaluated. Results On cadaver sections, the right pulmonary ligament attached the lower lobe of the right lung to the esophagus, while the left ligament attached the lower lobe of the left lung to the esophagus or the descending aorta. In 40 pleural effusion and 7 pneumothorax cases, the pulmonary ligament tethered the medial aspect of the collapsed lower lobe and limited the shift of the lower lobe. In 40 pleural effusions, the ligament divided the medial pleural space into an anterior and a posterior compartment. The ligament showed thickness due to the invasion of the lesions of lower lobe including 7 tumors and 3 inflammatory diseases. Conclusion The pulmonary ligament can affect the helical CT appearances of the lower thoracic disease, such as lobe collapse, pleural effusion and pneumothorax; while the intraparenchymal and mediastinal abnormality can extend into the pulmonary ligament.