SUMMARY: CNS lymphoma consists of 2 major subtypes: secondary CNS involvement by systemic lymphoma and PCNSL. Contrast-enhanced MR imaging is the method of choice for detecting CNS lymphoma. In leptomeningeal CNS lymphoma, representing two-thirds of secondary CNS lymphomas, imaging typically shows leptomeningeal, subependymal, dural, or cranial nerve enhancement. Single or multiple periventricular and/or superficial contrast-enhancing lesions are characteristic of parenchymal CNS lymphoma, representing one-third of secondary CNS lymphomas and almost 100% of PCNSLs. New CT and MR imaging techniques and metabolic imaging have demonstrated characteristic findings in CNS lymphoma, aiding in its differentiation from other CNS lesions. Advanced imaging techniques may, in the future, substantially improve the diagnostic accuracy of imaging, ultimately facilitating a noninvasive method of diagnosis. Furthermore, these imaging techniques may play a pivotal role in planning targeted therapies, prognostication, and monitoring treatment response.ABBREVIATIONS: ADC ϭ apparent diffusion coefficient; CBV ϭ cerebral blood volume; CE ϭ contrast enhancement; Cho ϭ choline; CNS ϭ central nervous system; Cr ϭ creatine; DWI ϭ diffusion-weighted imaging; FA ϭ fractional anisotropy; FDG ϭ fluorodeoxyglucose; HAART ϭ highly active antiretroviral therapy; HIV ϭ human immunodeficiency virus; MRI ϭ MR imaging; MS ϭ multiple sclerosis; NHL ϭ non-Hodgkin lymphoma; PCNSL ϭ primary CNS lymphoma; PET ϭ positron-emission tomography; PML ϭ progressive multifocal leukoencephalopathy; rCBV ϭ relative cerebral blood volume; SPECT ϭ single-photon emission CT; SPET ϭ single photon-emission tomography; SWI ϭ susceptibility-weighted imaging L ymphoma of the CNS consists of 2 major subtypes: secondary CNS involvement by systemic lymphoma (the most common) and PCNSL, in which the lymphoma is restricted to the brain, leptomeninges, spinal cord, or eyes, without evidence of it outside the CNS at primary diagnosis.

BACKGROUND AND PURPOSE:Studying imaging findings of non-acquired immunodeficiency syndrome (AIDS) primary central nervous system lymphoma (PCNSL), we hypothesized that the imaging presentation has changed with the increasing incidence of PCNSL and is related to clinical factors (eg, time to diagnosis and the patient's being diagnosed alive or at postmortem examination).

Background: General practitioners often diverge from clinical guidelines regarding spine radiography. This study aimed to identify and describe A) factors general practitioners consider may affect their decisions about ordering plain radiography for back pain and B) barriers to guideline adherence suggested by such factors.

BackgroundPrevious systematic reviews have reported positive associations between Modic changes (MCs) and low back pain (LBP), but due to their narrow scope and new primary studies, there is a need for a comprehensive systematic review. Our objectives were to investigate if MCs are associated with non-specific LBP and/or activity limitation and if such associations are modified by other factors.MethodsA protocol for this review was registered at PROSPERO prior to commencing the work (PROSPERO record: CRD42015017350). The MEDLINE, CINAHL and EMBASE databases were searched for relevant studies from first record to June 15th 2016. Prospective or retrospective cross-sectional cohort studies and case-control studies including people of all ages from general, working and clinical study populations were eligible for inclusion. Risk of bias assessment and data extraction for associations and potential modifiers were completed independently by pairs of reviewers. Meta-analysis was performed for homogeneous studies and presented as odds ratios (OR) with 95% CI.ResultsIn all, 5210 citations were identified and 31 studies were included. One study had low risk of bias. Fifteen studies (48%) reported statistically significant positive associations between MCs and LBP and one study found a statistically significant negative association. Meta-analysis performed for studies using concordant pain with provocative discography as the clinical outcome resulted in an OR of 4.01 (1.52–10.61). One of seven studies reported a statistically significant positive association between MCs and activity limitation. Lumbar disc level and disc degeneration were found to modify the association between MCs and LBP.ConclusionsThe results from this comprehensive systematic review indicate that the associations between MCs and LBP-related outcomes are inconsistent. The high risk of bias and the heterogeneity in terms of study samples, clinical outcomes and prevalence estimates of MCs and LBP may explain these findings. It is likely that new studies with low risk of bias will affect the direction and strength of these associations.