Comparison between PET and CT Findings for 7 Patients with a Pulmonary Lymphangitic Metastasis

ABSTRACT

PURPOSE: This study was conducted to compare the PET and CT findings for patients with a pulmonary lymphangitic metastasis. MATERIALS AND METHODS: We retrospectively reviewed the PET and CT findings of seven patients diagnosed with a pulmonary lymphangitic metastasis between May 2005 and May 2007. RESULTS: All patients had interstitial thickening, as seen on a CT scan, while the PET scans showed abnormal findings in only three patients. In these three patients, one patient had interlobular septal thickening of more than 10, another patient had interlobular septal thickening of more than 5 but less than 10, and another patient had interlobular septal thickening of less than 5. All of the patients had bronchovascular bundle thickening. However, among the four patients that had normal FDG uptake, no patient had interlobular septal thickening of more than 10, two of the patients had interlobular septal thickening of more than 5 but less than 10, and the remaining patients had interlobular septal thickening of less than 5. Only two of the patients had bronchovascular bundle thickening. CONCLUSION: All patients with pulmonary lymphangitic metastasis have typical CT findings, but some of the patients had FDG uptake, as seen in the PET scans. Thus, CT is a more useful modality for diagnosis for pulmonary lymphangitic metastases.