The Diagnostic Performance of Magnetic Resonance Imaging in the Categorization of Pediatric Neck Lymph Nodes: Radiologic and Pathologic Correlations.

BACKGROUND/AIM: To present MRI features of neck lymph nodes in benign and malignant conditions in the pediatric population. MATERIALS AND METHODS: MRIs of the neck of 51 patients 1 to 18 years old (40 boys, 11 girls [10.08±4.73]) with lymph node biopsy were retrospectively analyzed. Those were grouped as benign including reactive (27 [52.9%]) and lymphadenitis (11 [21.6%]), and malignant (13 [25.5%]). The groups were evaluated multiparametrically in terms of quantitative and qualitative variables. RESULTS: The long axis, short axis, area, and apparent diffusion coefficient (ADC) values of the largest lymph node were 21 (17 to 24) mm, 14 (12 to 18) mm, 228.60 (144.79 to 351.82) mm 2 , 2531 (2457 to 2714) mm 2 /s for reactive, 24 (19 to 27) mm, 15 (11 to 20) mm, 271.80 (231.43 to 412.20) mm 2 , 2534 (2425 to 2594) mm 2 /s for lymphadenitis, 27 (23.50 to 31.50) mm, 20 (15 to 22) mm, 377.08 (260.47 to 530.94) mm 2 , 2337 (2254 to 2466) mm 2 /s for malignant, respectively. Statistical analysis of our data suggests that the following parameters are associated with a higher likelihood of malignancy: long axis >22 mm, short axis >16 mm, area >319 cm 2 , ADC value <2367 mm 2 /s, and supraclavicular location. Perinodal and nodal heterogeneity, posterior cervical triangle location are common in lymphadenitis ( P <0.001). Reactive lymph nodes are distributed symmetrically in both neck halves ( P <0.001). CONCLUSION: In the MRI-based approach to lymph nodes, not only long axis, short axis, surface area, and ADC, but also location, distribution, perinodal, and nodal heterogeneity should be used.

Influenza A (H1N1)-Associated Acute Necrotizing Encephalopathy with Unusual Posterior Reversible Encephalopathy Syndrome in a Child.

Other than respiratory symptoms, influenza A (H1N1) can rarely cause neurological complications in children and adults. In this article, we aimed to present H1N1-associated acute necrotizing encephalopathy (ANE) and asymmetrical involvement of posterior reversible encephalopathy syndrome (PRES) in a 30-month-old male patient with clinical and radiological imaging findings. The patient who presented to the hospital with febrile convulsion and lethargy had elevated liver enzymes and coagulopathy. The magnetic resonance (MR) examination revealed diffusion restriction in bilateral cerebellar white matter, thalami, and periventricular white matter which was consistent with ANE. Susceptibility-weighted imaging (SWI) sequence showed hemorrhage in bilateral thalami and cerebellar white matter. There was high signal on fluid-attenuated inversion recovery (FLAIR) sequences in right temporooccipital cortical, subcortical, and periventricular white matter suggestive of PRES. MR angiography showed vasculopathy which is supportive for PRES. This is the second case of H1N1-associated pediatric PRES reported in the literature.