中文摘要：

目的探讨基于体素内不相干运动（IVIM）理论MRDWI技术在鼻咽癌（NPC）应用的可行性，进一步探讨真实扩散系数（D值）、灌注相关扩散系数（D。值）及灌注分数（f值）在首发鼻咽癌的诊断价值。方法选择2011年12月至2013年1月临床怀疑鼻咽癌患者40例，男26例、女14例，中位年龄52岁。患者均行3．0TMR扫描，IVIMDWI采用13个b值（0、10、20、30、50、80、100、150、200、300、400、600、800s／mm2）。患者MR检查后0～11d（平均间隔3d）均行鼻咽部活检；根据不同病理结果分为2组，A组为NPC组（男17例、女9例，中位年龄54岁），B组为鼻咽慢性增生性炎症（NPH）组（男9例、女5例，中位年龄35岁）。IVIM参数值D值、D＊值及f值的比较采用非参数Mann—Whitney检验法。结果40例中完成IVIMDWI的患者共36例（其中，A组26例中完成24例，B组14例中完成12例）。A组D值为（0．70±0．13）×10^-3 mm2／s，和B组（0．78±0．05）×10^-3 mm2／s相比，差异有统计学意义（U=2．05，P〈0．05）。A组的f值为（16．25±1．46）％，B组为（26．20±3．90）％，差异有统计学意义（U=11．16，P〈0．01）；而D＊值A组为（161．8±23．56）×10^-3mm2／s，B组为（55．28±17．05）×10^-3mm^2／s，A组较B组显著增高（U=13．90，P〈0．01）。结论IVIM DWI技术在鼻咽癌的应用是切实可行的，不同D值对鼻咽癌及鼻咽部慢性炎症具有一定的鉴别价值，D＊值在鼻咽部良恶性疾病鉴别诊断方面具有潜在的重要价值。

英文摘要：

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 groupromean, （161.8 ±23.56） ×10^-3 mm2/s vs （55.28 ± 17.05）×10^-3mm2/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.