Table 2.
Characteristics of MRI of included studies
| Study | Magnet | Pulse sequences | Diagnostic criteria |
|---|---|---|---|
| Ohno et al. 200438 | 1.5-T superconducting magnet | Transverse ECG and respiratory-triggered STIR TSE | Quantitative: LSR ≥ 0.6.Qualitative: signal intensity of lymph node was greater than that of muscle. |
| Ohno et al. 200739 | 1.5-T superconducting magnet | Axial and coronal STIR TSE | Quantitative: LSR ≥ 0.6. |
| Kim et al.40 | 3-T superconducting magnet | Breath-hold T1-weighted TFE sequenceBreath-hold cardiac-gated T2-weighted TSE (TIBB) | Quantitative: LTR ≥ 0.84.Qualitative: nodal morphologic characteristics (eccentric cortical thickening or obliteration of the fatty hilum of lymph node); lymph node size. |
| Hasegawa et al.41 | 1.5-T superconducting magnet | Transverse non-breath-hold DWI (STIR EPI)Transverse electrocardiographically and respiratory-triggered T2-weighted sequence | Qualitative: lymph node metastasis was defined as a focus of low signal intensity on DWI with a visible lymph node on corresponding T2-weighted image. |
| Nomori et al.42 | 1.5-T superconducting magnet | Coronal T1-weighted sequenceCoronal and axial T2-weighted sequenceCoronal and axial STIR sequenceTransverse DWI (EPI) | Quantitative: ADCLN-min ≤ 1.6 × 10−3 mm2/s. |
| Yi et al.43 | 3-T superconducting magnet | Breath-hold T1-weighted TFE sequenceBreath-hold cardiac-gated T2-weighted TSE (TIBB) | Qualitative: nodal morphologic characteristics (eccentric cortical thickening or obliteration of the fatty hilum of lymph node). |
| Nakayama et al.44 | 1.5-T superconducting magnet | Transverse T1-weighted and T2-weighted sequencesTransverse DWI (HASTE)Transverse breath-hold STIR TSE | Quantitative STIR: LSR ≥ 0.354.Quantitative DWI: ADCLN ≤ 1.54 × 10−3 mm2/s. ADCLC-ADCLN ≤ 0.24 × 10−3 mm2/s. |
| Ohno et al. 201145 | 1.5-T superconducting magnet | Axial and coronal breath-hold STIR TSEThree axes (axial, sagittal, and coronal) DWI (STIR EPI) | Quantitative STIR: LSR ≥ 0.6. LMR ≥ 1.4.Quantitative DWI: ADCLN ≤ 2.5 × 10−3 mm2/s.Qualitative STIR or DWI: signal intensity of lymph node was greater than that of muscle. |
| Usuda et al.46 | 1.5-T superconducting magnet | Coronal T1-weighted SECoronal and axial T2-weighted FSERespiratory triggered DWI (SS EPI with SPAIR) | Quantitative DWI: ADCLN ≤ 1.7 × 10−3 mm2/s. |
ADCLC, apparent diffusion coefficient value of lung cancer; ADCLN, ADC value of lymph node; DWI, diffusion-weighted imaging; ECG, electrocardiogram; EPI, echo-planar imaging; FS, fat suppression; FSE, fast spin-echo; HASTE, half-Fourier acquisition single-shot turbo spin echo; LMR, lymph node to muscle ratio of signal intensity; LSR, lymph node to saline ratio of signal intensity; LTR, lymph node to tumor ratio of signal intensity; MRI, magnetic resonance imaging; SPAIR, spectral presaturation attenuated inversion recovery; SS, single shot; STIR, short time inversion recovery; TFE, turbo field-echo; TIBB, triple-in-version black-blood; TSE, turbo spin echo.