Newly diagnosed lymphoma: initial results with whole-body T1-weighted, STIR, and diffusion-weighted MRI compared with 18F-FDG PET/CT.

OBJECTIVE: The purpose of this study was to compare whole-body MRI including diffusion-weighted imaging (DWI) with (18)F-FDG PET/CT in the staging of newly diagnosed lymphoma. SUBJECTS AND METHODS: Twenty-two consecutively registered patients with newly diagnosed lymphoma prospectively underwent whole-body MRI (22 with T1-weighted, STIR, and DWI sequences and 21 with T1-weighted and STIR sequences but not DWI) and FDG PET/CT. Whole-body MRI-DWI was independently evaluated by two blinded observers. Interobserver agreement was assessed, and whole-body MRI-DWI was compared with FDG PET/CT. RESULTS: The kappa values for interobserver agreement on whole-body MRI-DWI for all nodal regions together and for all extranodal regions together were 0.676 and 0.452. The kappa values for agreement between whole-body MRI-DWI and FDG PET/CT for all nodal regions together and for all extranodal regions together were 0.597 and 0.507. Ann Arbor stage according to whole-body MRI-DWI findings was concordant with that of FDG PET/CT findings in 77% (17/22) of patients. Understaging and overstaging relative to the findings with FDG PET/CT occurred in 0% (0/22) and 23% (5/22) of cases. In the care of 9% (2/22) of patients, overstaging with whole-body MRI-DWI relative to staging with FDG PET/CT would have had therapeutic consequences. CONCLUSION: Our early results indicate that overall interobserver agreement on whole-body MRI-DWI findings is moderate to good. Overall agreement between whole-body MRI-DWI and FDG PET/CT is moderate. In the care of patients with newly diagnosed lymphoma, staging with whole-body MRI-DWI does not result in underestimation of stage relative to the results with FDG PET/CT. In a minority of patients, reliance on whole-body MRI-DWI leads to clinically important overstaging relative to the results with FDG PET/CT. FDG PET/CT remains the reference standard for lymphoma staging until larger-scale studies show that use of whole-body MRI-DWI results in correct staging in this minority of cases.

ADC measurements in the evaluation of lymph nodes in patients with non-Hodgkin lymphoma: feasibility study.

OBJECT: To determine whether apparent diffusion coefficient (ADC) measurements allow discrimination of normal lymph nodes from lymphomatous lymph nodes, and indolent lymphomas from aggressive lymphomas in patients with non-Hodgkin lymphoma (NHL). MATERIALS AND METHODS: Eighteen healthy volunteers and thirty-two patients with newly diagnosed NHL (indolent: n = 16; aggressive: n = 16) underwent diffusion-weighted imaging. ADCs of normal lymph nodes were compared to those of lymphomatous lymph nodes, and ADCs of indolent lymphomas were compared to those of aggressive lymphomas. Receiver operating characteristic (ROC) analysis was performed when ADCs were significantly different between two of the aforementioned groups. RESULTS: ADCs (in 10(-3) mm(2)/s) of lymphomatous lymph nodes (0.70 ± 0.22) were significantly lower (P < 0.0001) than those of normal lymph nodes (1.00 ± 0.15). Area under the ROC curve was 0.865. Sensitivity and specificity were 78.1 and 100% when using an optimal cutoff ADC value of 0.80. On the other hand, ADCs of indolent lymphomas (0.67 ± 0.21) were not significantly different (P = 0.2997) from those of aggressive lymphomas (0.74 ± 0.23). CONCLUSION: ADC measurements show promise as a highly specific tool for the discrimination of normal lymph nodes from lymphomatous lymph nodes, but appear to be of no utility in differentiating indolent from aggressive lymphomas.

Whole-body MRI, including diffusion-weighted imaging, for the initial staging of malignant lymphoma: comparison to computed tomography.

PURPOSE: To assess the value of whole-body magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI), for the initial staging of malignant lymphoma, compared with computed tomography (CT). MATERIALS AND METHODS: Thirty-one consecutive patients with newly diagnosed malignant lymphoma prospectively underwent whole-body MRI (T1-weighted and short inversion time inversion recovery [n = 31], and DWI [n = 28]) and CT. Ann Arbor stages were assigned by 1 radiologist according to whole-body MRI findings, and by another radiologist according to CT findings. Differences in staging between whole-body MRI (without and with DWI) and CT were resolved using other (imaging) studies (including 18F-fluoro-2-deoxyglucose positron emission tomography and bone marrow biopsy) and follow-up studies as reference standard. RESULTS: Staging results of whole-body MRI without DWI were equal to those of CT in 74% (23/31), higher in 26% (8/31), and lower in 0% (0/31) of patients, with correct/incorrect/unresolved overstaging relative to CT in 3, 2, and 2 patients, respectively, and incorrect staging of both modalities in 1 patient. Staging results of whole-body MRI with DWI were equal to those of CT in 75% (21/28), higher in 25% (7/28), and lower in 0% (0/28) of patients, with correct/incorrect overstaging relative to CT in 6 and 1 patient(s), respectively. CONCLUSION: Our results suggest that initial staging of malignant lymphoma using whole-body MRI (without DWI and with DWI) equals staging using CT in the majority of patients, whereas whole-body MRI never understaged relative to CT. Furthermore, whole-body MRI mostly correctly overstaged relative to CT, with a possible advantage of using DWI.

The prevalence of diffuse idiopathic skeletal hyperostosis in an outpatient population in The Netherlands.

OBJECTIVE: In diffuse idiopathic skeletal hyperostosis (DISH), spinal ankylosis may occur due to longitudinal ligament ossification. DISH can lead to back pain, impaired mobility, and displaced fractures after minor trauma. Its etiology is unknown, but is associated with obesity and type 2 diabetes mellitus. We investigated the prevalence of DISH in an outpatient population in the Netherlands. METHODS: Chest radiographs of 501 patients (age > 50 yrs) referred to our institution by general practitioners for non-spine-related conditions were reviewed. DISH was established according to defined criteria; 3-level involvement was defined as pre-stage DISH. Logistic regression analysis was used to investigate the influence of age and sex on the prevalence of DISH. RESULTS: The overall prevalence of DISH was 17.0% (95% CI 13.7-20.3). A significant increase with age was observed (odds ratio 1.03, 95% CI 1.01-1.05; p = 0.006). The odds ratio of male sex was 1.85 (95% CI 1.20-2.86; p = 0.006). The individual predicted probability of developing DISH was 32.1% in 80-year-old men and 16.9% in women of the same age. Pre-stage DISH was found in 4.6% of the individuals and was more frequent in women. CONCLUSION: The prevalence of DISH in this outpatient cohort was 17.0%, which is high compared to recent reports. Age and sex were significantly related to the presence of DISH, suggesting that men and older individuals have a higher probability of developing DISH.