Objective To investigate the feasibility of diffusion-weighted(DWI) MRI on basis of the intravoxel incoherent motion (IVIM) in nasopharyngeal carcinoma (NPC),and the diagnostic value of pure molecular diffusion coefficient (D),perfusion-related diffusion coefficient (D *) and perfusion fraction (f) in first onset NPC.Methods From December 2011 to January 2013,40 consecutive patients (26 men,14 women; median age,52 years) with suspected NPC were examined on a 3.0 T MR scanner.DW imaging was performed by using a single-shot echo-planar sequence with 13 b-values (0,10,20,30,50,80,100,150,200,300,400,600,800 s/mm2).MR imaging was compared with endoscopy and biopsy for the detection of NPC.Mean interval time between MR imaging examination and subsequent nasopharyngeal biopsy was 3 days (range,0-11 days).The subjects were divided into 2 groups according to the pathological results,group A was subjects with NPC (17 men,9 women; median age,35) and group B was ones with nasopharyngeal chronic hyperplastic inflammation(NPH) (9 men,5 women; median age,35).The D,D * and f were measured and compared in patients with first onset NPC and nasopharyngeal hyperplasia (Mann-Whitney test).Results IVIM DWI was successful in 24/26 with NPC and 12/14 with NPH.D value was significantly lower in A group compared with B group [mean,(0.70 ± 0.13) ×10-3 mm2/s vs (0.78 ± 0.05) × 10-3 mm2/s ; U =2.05,P ＜ 0.05],as was f value [mean,(16.25 ±1.46) ％ vs (26.20 ± 3.90) ％ ; U =11.16,P ＜ 0.01].However,D* value was significantly higher in Agroupas compared with B group[mean,(161.8 ±23.56) × 10-3 mm2/s vs (55.28 ± 17.05) × 10-3 mm2/s; U =13.90,P ＜0.01].Conclusions IVIM DWI is a feasible technique for investigating first onset NPC and D value has a certain value in differentiating NPC and NPH.D* value has an important potential value in distinguishing benign and malignant NPC.

OBJECTIVETo investigate the changes in brain regional homogeneity in first-onset major depressive disorders (MDDs) using resting-state functional magnetic resonance imaging (fMRI).

METHODSEighteen patients with first-onset MDDs and twenty gender- and age-matched healthy controls underwent resting-state fMRI scans to compare the regional homogeneities of the brain regions.

RESULTSCompared with the normal controls, the patients with MDDs showed significantly decreased regional homogeneity in the left posterior cingulated gyrus, bilateral inferior temporal gyrus, bilateral superior temporal gyrus, left inferior frontal gyrus, left hippocampa gyrus, left posterior central gyrus, left angular gyrus, right amygdala, right orbital frontal gyrus, right supplementary motor area, and right cerebellar lobe.

CONCLUSIONPatients with first-onset MDDs have dysfunctions in the brain regions closed related with cognition and emotional control.

Amygdala ; Brain ; physiopathology ; Case-Control Studies ; Cerebellum ; Cognition ; Depressive Disorder, Major ; diagnosis ; Emotions ; Frontal Lobe ; Humans ; Magnetic Resonance Imaging ; Temporal Lobe