Intravoxel incoherent motion diffusion-weighted imaging in differential diagnosis of primary nasopharyngeal carcinoma and nasopharyngeal hyperplasia / 中华放射学杂志

ABSTRACT

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.