F-18-FDG-avid lymph node metastasis along preferential lymphatic drainage pathways from the tumor-bearing lung lobe on F-18-FDG PET/CT in patients with non-small-cell lung cancer.

OBJECTIVE: F-18-FDG-avid lymph node (LN) metastasis may preferentially occur along the lymphatic drainage pathway (LDP) from the tumor-bearing lobe in patients with non-small cell lung cancer (NSCLC) on FDG PET/CT. This study evaluated whether the identification of metastatic LNs according to LDP-based visual image interpretation can improve LN staging on FDG PET/CT in these patients. METHODS: FDG PET/CT study was performed in 265 patients with NSCLC. The presence and LN station of metastatic LNs were determined by surgery or the clinical course. In the LDP-based interpretation, FDG-avid LNs, which were located along the preferential LDP from each tumor-bearing lobe and visually more intense in FDG uptake compared with the remaining LNs straying away from the preferential LDP, were diagnosed as metastatic. The result was compared with the quantitative method using a cutoff value of 2.5 for the maximum standardized uptake value. RESULTS: Of the total 1031 mediastinal and hilar LN stations with FDG-avid LNs in 265 patients, 179 stations in 66 patients were metastatic and the remaining 852 were benign. All the metastatic LN stations except for 2 stations showing skip metastasis were located along the main preferential LDP or another preferential LDP via a direct anatomic pathway from each tumor-bearing lung lobe. The specificity, accuracy, and PPV for identifying metastatic LN stations by LDP-based interpretation were 97.9, 95.7 and 89.5 %, respectively, which were significantly greater compared with those of 92.7, 90.8 and 70.3 % by the SUV-based method (P < 0.001). CONCLUSIONS: The present study shows that FDG-avid LN metastasis preferentially occurs along the LDP from the tumor-bearing lobe in NSCLC patients. LDP-based visual image interpretation on FDG PET/CT can improve LN staging in these patients.

Systolic reconstruction in patients with low heart rate using coronary dual-source CT angiography.

OBJECTIVES: The purpose of our study was to determine the relationship between the predictive factors and systolic reconstruction (SR) as an optimal reconstruction window in patients with low heart rate (LHR; less than 65 bpm). METHODS: 391 patients (262 male and 129 female, mean age; 67.1±10.1 years of age) underwent coronary CTA without the additional administration of a beta-blocker. Affecting factors for SR were analyzed in age, gender, body weight (BW), diabetes mellitus (DM), coronary arterial disease (CAD), ejection fraction (EF), systolic and diastolic body pressure (BP) and heart rate variability (HRV) during coronary CTA. RESULTS: In 29 (7.4%) of the 391 patients, SR was needed, but there was no apparent characteristic difference between the systolic and diastolic reconstruction groups in terms of gender, age, BW, DM, CAD and EF. In a multivariate analysis, the co-existence of DM [P<0.05; OR, 0.27; 95% CI, 0.092-0.80], diastolic BP [P<0.01; OR, 0.95; 95% CI, 0.92-0.98] and HRV [P<0.01; OR, 0.98; 95% CI, 0.96-0.99] were found to be the factors for SR. In gender-related analysis, HRV was an important factor regardless of sex, but co-existence of DM affected especially for female and BP for male. CONCLUSION: Especially in the patients with LHR who had a medication of DM, high HRV or high BP, SR, in addition to DR, was needed to obtain high-quality coronary CTA images.