Identification of the pericardiacophrenic vein on CT

BACKGROUND: To evaluate the depictability of pericardiacophrenic veins (PCPV) as landmarks for the location of the phrenic nerves on multi-detector-row computed tomography (MDCT), and to investigate the usefulness of depicting the PCPV to aid differential diagnosis of anterior mediastinal lesions. METHODS: Fifty-six patients with anterior mediastinal lesions (Fifty lesions originated from the thymus, six were of non-thymic origin) were evaluated. Contrast-enhanced CT scans of the chest were performed in all cases before diagnosis, and 22 of these scans were performed with electrocardiographic (ECG) gating. Two chest radiologists assessed the depictability of the PCPV and the positional relationship between the center of each anterior mediastinal lesion and the ipsilateral PCPV. RESULTS: The use of ECG gating increased the PCPV depiction rate in the lower left part of the mediastinum. The depiction rate of the left PCPV was significantly higher than that of the right PCPV. All 50 tumors of thymic origin and 3 of the 6 tumors of non-thymic origin were located on the medial side of the ipsilateral PCPV. The 3 lesions located on the lateral side of the ipsilateral PCPV were of non-thymic origin (p = 0.0007). CONCLUSION: The use of ECG gating during MDCT may improve the depictability of the PCPV in the lower left section of the anterior mediastinum. Solitary anterior mediastinal lesions located on the lateral side of the ipsilateral PCPV are likely to be of non-thymic origin.