MRI与CT在鼻咽癌诊断中的应用价值及分期系统比较

摘要

目的 评价MRI与CT检查在鼻咽癌诊断中的应用价值,并对鼻咽癌2008年分期、1992年福州分期及2002年国际抗癌联盟(UICC)分期系统进行比较.方法 分析76例鼻咽癌初诊患者MRI和CT影像资料,依据2008年分期以MRI为标准,评价MRI与CT对鼻咽癌新分期的差异.并以MRI为标准,比较鼻咽癌不同分期系统间的差异.MRI与CT对肿瘤侵犯范围比较采用McNemar法检验.结果 MRI判断鼻咽癌翼内肌(22例)、翼外肌(15例)、颅底(35例)及颅内(11例)侵犯方面与CT(分别为24、11、32、6例)存在差异,但无统计学意义(P＞0.05);MRI在判断咽旁间隙侵犯(50例)、咽后组淋巴结转移(48例)、T1期(18例)、T2期(15例)、N0期(18例)、N1期(33例)上,与CT(分别为61、23、11、22、24、27例)不一致者分别为11例、25例、7例、7例、6例及6例,差异有统计学意义(P＜0.05).CT多显示的11例咽旁间隙侵犯,MRI证实5例为咽旁间隙受压,6例为咽后组淋巴结转移,而MRI较CT共多显示咽后组淋巴结转移25例,以上2点为引起T、N分期差异的主要原因.鼻咽癌2008年分期与1992年分期比较,T分期上升9例,下降1例,N分期上升16例,临床分期上升15例,下降1例;与2002年UICC分期比较,T分期上升7例,N分期上升10例,临床分期上升12例.结论 与鼻咽癌2008分期规定的MR检查比较,CT在显示病变咽旁间隙侵犯及咽后组淋巴结转移方面存在较大差异.相对于1992年分期及2002年UICC分期,鼻咽癌2008分期主要使肿瘤T、N分期上升、临床分期上升.%Objective To evaluate the value of MR and CT examinations in the diagnosis of nasopharyngeal carcinoma (NPC) and compare 2008 staging system with 1992 staging system and 2002 UICC staging system for NPC. Methods MR and CT images of seventy-six cases with NPC were studied. According to 2008 staging system and taking MR as a standard, differences between these two examinations were evaluated under the new NPC staging system, and three staging system were compared by MR findings. Results MR was inconsistent with CT in eveluating invasion of medial pterygoid muscle(22,24 cases), lateral pterygoid muscle( 15, 11 cases), skull base(35, 32 cases) and intracranial fossa( 11,6 cases), but no statistical diffence existed ( P ＞ 0. 05 ). There were statistical difference ( P ＜ 0. 05 )between MR and CT in determining invasion of parapharyngeal space( 50, 61 cases), retropharyngeal lymph node metastasis(48, 23 cases), stage T1 (18, 11 cases), T2 (15, 22 cases), N0 (18, 24 cases) and N1(33, 27 cases) with differences of 11 cases, 25 cases, 7 cases, 7 cases, 6 cases and 6cases respectively.For invasion of parapharyngeal space, CT showed 11 cases more than MR while 5 cases were comfirmed as compression by local tumor and 6 cases were proved as retropharyngeal lymph node metastasis according to MR. For retropharyngeal lymph node metastasis, MR presented 25 cases more than CT. These two reasons above mainly caused the differences of T-staging and N-staging. For 2008 staging system, when compared with 1992 staging system, there were 9 cases upstaging and 1 case downstaging in T classification, 16 cases upstaging in N classification, and 15 cases upstaging and 1 case downstaging in clinical classification; and when compared with 2002 UICC staging system, there were 7 cases, 10 cases and 12 cases upstaging in T,N, and clinical staging respectively. Conclusions Compared with MR examination which was regarded as standard by 2008 staging system of NPC, there were some differences in demonstrating invasion of parapharyngeal space and retropharyngeal lymph node metastasis by CT. Compared to 1992 staging system and 2002 UICC staging system, 2008 staging system mainly made T and N classification of tumor upstage,resulting in upstaging in clinical classification.