Whole-body diffusion-weighted imaging with background body signal suppression and quantitative apparent diffusion coefficient in the detection, staging, and grading of non-Hodgkin lymphoma.

Purpose: Assess reproducibility of detection, staging, and grading of non-Hodgkin lymphoma (NHL) using whole-body diffusion-weighted imaging with background body signal suppression (WB-DWIBS). Material and methods: Thirty NHL patients underwent WB-DWIBS, divided into 2 groups according to staging and grading. Image analysis and apparent diffusion coefficient (ADC) measurement of the largest lymph node in each group were performed by 2 observers. Inter-observer agreement was performed. Results: Overall inter-observer agreement for detection of NHL was excellent (k = 0.843; 92.05%) with excellent inter-observer agreement of nodal disease (cervical, thoracic and abdominal) (k = 0.783, 0.769, and 0.856; 96.67%, 90.0%, and 93.3% respectively), extra-nodal disease (k = 1; 100%), and splenic involvement (k = 0.67; 83.3%). The overall inter-observer agreement of DWIBS in staging of NHL was excellent (k = 0.90; 94.9%) with excellent inter-observer agreement for stage I (k = 0.93; 96.4%), stage II (k = 0.90; 94.8%), stage III (k = 0.89; 94.6%), and stage IV (k = 0.88; 94.0%). There was significant difference between ADC in stage I, II (0.77 ± 0.13, 0.85 ± 0.09 × 10-3 mm2/s), and stage III, IV (0.63 ± 0.08, 0.64 ± 0.11 × 10-3 mm2/s, p < 0.002, < 0.001). Interclass correlation showed almost perfect agreement for ADC measurement in staging and grading groups (r = 0.96 and r = 0.85, respectively, p < 0.001). There was significant difference between ADC in aggressive lymphoma (0.65 ± 0.1, 0.67 ± 0.13 × 10-3 mm2/s) and indolent lymphoma (0.76 ± 0.14, 0.84 ± 0.09 × 10-3 mm2/s, p < 0.028, < 0.001). Conclusion: DWIBS is reproducible for detection and staging of nodal and extra-nodal involvement in patients with NHL. ADC can quantitatively participate in the staging and grading of NHL.

Whole-body diffusion-weighted imaging with background body signal suppression in the detection of osseous and extra-osseous metastases.

PURPOSE: To assess the reproducibility of detection of osseous and extra-osseous metastases in cancer patients using whole-body diffusion-weighted imaging with background body signal suppression (WB-DWIBS). MATERIAL AND METHODS: A prospective study was conducted on 39 consecutive patients (21 females, 18 males; mean age 48 years) with metastases, who underwent WB-DWIBS on a 1.5-T MR scanner. Image analysis was performed independently by two blinded observers. Inter-observer agreement was assessed for the detection of osseous (spinal, appendicular) and extra-osseous (hepatic, pulmonary, nodal, and peritoneal) metastases. RESULTS: The overall inter-observer agreement of WB-DWIBS in the detection of osseous and extra-osseous metastases was excellent (κ = 0.887, agreement = 94.44%, p = 0.001). There was excellent inter-observer agreement of both observers for the detection of osseous spinal (κ = 0.846, agreement = 92.3%), osseous appendicular (κ = 0.898, agreement = 94.8 %), hepatic (κ = 0.847, agreement = 92.3%), pulmonary (κ = 0.938, agreement = 97.4%), nodal metastases (κ = 0.856, agreement = 94.9%), and peritoneal metastasis (κ = 0.772, agreement = 94.9%). CONCLUSION: We concluded that WB-DWIBS is reproducible for detection of osseous and extra-osseous metastases in cancer patients.