Whole body MRI with qualitative and quantitative analysis of DWI for assessment of bone marrow involvement in lymphoma

Aim: Our study aimed to investigate the role of qualitative and quantitative whole body MRI with DWI for assessment of bone marrow involvement (BMI) in newly diagnosed lymphoma using FDG PET\u2013CT and bone marrow biopsy (BMB) as reference standard. Materials and methods: We retrospectively evaluated 56 patients with newly diagnosed lymphoma (21 Hodgkin\u2019s lymphoma and 35 non-Hodgkin\u2019s lymphoma) who underwent random unilateral BMB, FDG PET\u2013CT and Wb-MRI-DWI for initial staging. In a patient-based analysis, results of Wb-MRI-DWI were compared with FDG PET\u2013CT and BMB. For quantitative analysis, mean ADC values of posterior iliac crest were correlated with BMI and bone marrow cellularity. Results: WB-MR-DWI obtained excellent concordance with FDG PET\u2013CT both in HL (k = 1.000; 95% CI 1.000\u20131.000) and in DLBCL (k = 1.000; 95% CI 1.000\u20131.000). In other NHL, WB-MRI-DWI obtained a good correlation with BMB (k = 0.611; 95% CI 0.295\u20130.927) while FDG PET\u2013CT had poor concordance (k = 0.067; 95% CI 0.372\u20130.505). WB-MR-DWI has no false negative errors but 4 false positive results consisting in focal lesions consensually reported by FDG PET\u2013CT and resolved after therapy. No significant correlation between ADC mean value and BMI was found (p = 0.0586). Conclusion: Our data suggest that Wb-MRI-DWI is a valid technique for BMI assessment in lymphoma patients, thanks to its excellent concordance with FDG PET\u2013CT and good concordance with BMB (superior than FDG PET\u2013CT). If further investigations will confirm our results on larger patient groups, it could become a useful tool in the clinical workup

Whole-body MRI with diffusion-weighted imaging : A valuable alternative to contrast-enhanced CT for initial staging of aggressive lymphoma.

AIM: To compare the accuracy of whole-body magnetic resonance imaging (Wb-MRI) with diffusion-weighted imaging (DWI) to that of contrast-enhanced computed tomography (CE-CT) and 2-[(18)F]-fluoro-2-deoxy-d-glucose ((18)F-FDG) positron-emission tomography co-registered with low dose-CT (PET-CT) in defining lymphoma disease stage. MATERIALS AND METHODS: From February 2010 to May 2014, 41 lymphoma patients underwent Wb-MRI-DWI, CE-CT, and (18)F-FDG PET-CT. Histological subtypes included aggressive B-cell (n=11), follicular (n=13), mantle cell (n=3), and Hodgkin's (n=14) lymphoma. To compare the procedures, the reference standard (RS) assessment was defined by combining the results from (18)F-FDG PET-CT, CE-CT, and bone marrow (BM) histology, modifications after therapy, and histological re-assessments of uncertain lesions. RESULTS: Among 1025 nodal sites, 217 had disease involvement according to the RS. CE-CT yielded 23 false-negative and 11 false-positive errors. Wb-MRI-DWI failed to recognise 17 localisations and had six false-positive errors; (18)F-FDG PET-CT had no errors. Among 458 extranodal sites, 37 were positive according to the RS. (18)F-FDG PET-CT yielded four false-negative and two false-positive results. CE-CT yielded 17 false-negative errors. Wb-MRI-DWI yielded a single false-negative error. Wb-MRI-DWI was the most reliable imaging technique for BM evaluation. Considering each procedure alone, the final stage would have been missed in four cases using (18)F-FDG PET-CT, 12 cases using CE-CT, and none using Wb-MRI-DWI. CONCLUSION: The present data support Wb-MRI-DWI as a sensitive and specific imaging technique for lymphoma evaluation, supporting its use in place of CE-CT for staging