Background: Computed diffusion-weighted imaging (cDWI) is a mathematical computation technique that generates DWIs for any b-value by using actual DWI (aDWI) data with at least two different b-values and may improve differentiation of metastatic from nonmetastatic lymph nodes. Purpose: To determine the appropriate b-value for cDWI to achieve a better diagnostic capability for lymph node staging (N-staging) in non-small cell lung cancer (NSCLC) patients compared to aDWI, short inversion time (TI) inversion recovery (STIR) imaging, or positron emission tomography with 2-[fluorine-18] fluoro-2-deoxy-d-glucose combined with computed tomography (FDG-PET/CT). Study Type: Prospective. Subjects: A total of 245 (127 males and 118 females; mean age 72 years) consecutive histopathologically confirmed NSCLC patients. Field Strength/Sequence: A 3 T, half-Fourier single-shot turbo spin-echo sequence, electrocardiogram (ECG)-triggered STIR fast advanced spin-echo (FASE) sequence with black blood and STIR acquisition and DWI obtained by FASE with b-values of 0 and 1000 sec/mm2. Assessment: From aDWIs with b-values of 0 and 1000 (aDWI1000) sec/mm2, cDWI using 400 (cDWI400), 600 (cDWI600), 800 (cDWI800), and 2000 (cDWI2000) sec/mm2 were generated. Then, 114 metastatic and 114 nonmetastatic nodes (mediastinal and hilar lymph nodes) were selected and evaluated with a contrast ratio (CR) for each cDWI and aDWI, apparent diffusion coefficient (ADC), lymph node-to-muscle ratio (LMR) on STIR, and maximum standard uptake value (SUVmax). Statistical Tests: Receiver operating characteristic curve (ROC) analysis, Youden index, and McNemar's test. Results: Area under the curve (AUC) of CR600 was significantly larger than the CR400, CR800, CR2000, aCR1000, and SUVmax. Comparison of N-staging accuracy showed that CR600 was significantly higher than CR400, CR2000, ADC, aCR1000, and SUVmax, although there were no significant differences with CR800 (P = 0.99) and LMR (P = 0.99). Data Conclusion: cDWI with b-value at 600 sec/mm2 may have potential to improve N-staging accuracy as compared with aDWI, STIR, and PET/CT. Evidence Level: 2. Technical Efficacy: Stage 2.
All Science Journal Classification (ASJC) codes
- Radiology Nuclear Medicine and imaging