Table 1. CT and 18F-FDG PET Findings of Benign Cysts And TETs in Anterior Mediastinum.
| CT and 18F-FDG PET Findings | TETs (n = 132) | Benign Cysts (n = 130) | P |
|---|---|---|---|
| Morphologic findings | |||
| Long-axis diameter (cm) | 3.4 ± 1.0 | 2.1 ± 0.9 | < 0.001 |
| Short-axis diameter (cm) | 2.6 ± 3.5 | 1.5 ± 0.6 | < 0.001 |
| Superior location above heart (vs. inferior location) (%) | 88 (116) | 96 (125) | 0.021 |
| Lobulating contour (vs. smooth) (%) | 63 (83) | 17 (22) | < 0.001 |
| Ill-defined margin (vs. well-defined) (%) | 20 (27) | 6 (8) | 0.001 |
| Oval/irregular shape (vs. round) (%) | 76 (100) | 69 (90) | 0.238 |
| Calcification (%) | 11 (14) | 2 (3) | 0.010 |
| Gross fat | 0 | 0 | N/A |
| Ancillary findings (%) | |||
| Adjacent organ invasion | 7 (9) | 0 | 0.003 |
| Pleural effusion | 2 (3) | 0 | 0.247 |
| Pericardial effusion | 0 | 0 | N/A |
| Lymphadenopathy | 4 (5) | 0 | 0.060 |
| Satellite nodule | 5 (6) | 2 (3) | 0.5 |
| Metastasis | 6 (8) | 0 | < 0.001 |
| Relationship between lesion and adjacent mediastinal pleura | |||
| Visual categorization (%) | |||
| No abutment | 6 (8) | 20 (26) | < 0.001 |
| Abutment | 11 (15) | 67 (88) | |
| Protrusion | 83 (109) | 13 (16) | |
| Protrusion length (mm) | 10.0 ± 8.7 | 0.8 ± 2.9 | < 0.001 |
| Protrusion ratio (%) | 32.3 ± 33.0 | 3.0 ± 8.9 | < 0.001 |
| CT attenuation (HU) | (n = 52) | (n = 45) | |
| Pre-contrast CT attenuation | 47.3 ± 12.1 | 31.4 ± 18.0 | < 0.001 |
| Post-contrast CT attenuation | 88.8 ± 28.0 | 44.1 ± 21.9 | < 0.001 |
| Absolute enhancement | 41.5 ± 27.8 | 12.8 ± 21.4 | < 0.001 |
| 18F-FDG PET/CT | (n = 28) | (n = 12) | |
| SUVmax | 5.3 ± 2.4 | 1.1 ± 0.3 | < 0.001 |
Data in parenthesis indicate number of patients. CT = computed tomography, HU = Hounsfield unit, N/A = not applicable, PET = positron emission tomography, SUVmax = maximum standardized uptake value, TET = thymic epithelial tumor, 18F-FDG = fluorine-18-labeled fluoro-2-deoxy-D-glucose