螺旋CT与MRI评价鼻咽癌颅底侵犯

Spiral Computed Tomography(CT)and Magnetic Resonance Imaging(MRI)in Assessment of the Skull Base Encro achment in Nasopharyngeal Carcinoma

背景与目的:随着螺旋CT与MRI的普遍应用,研究哪种方法对鼻咽癌发生颅底侵犯的诊断更有价值,是临床上亟待解决的问题。本研究拟探讨用CT与MRI诊断鼻咽癌颅底侵犯的价值。方法:选取1993年8月～2001年9月经病理证实为鼻咽癌的患者61例,全组患者治疗前均行螺旋CT及MRI检查。此外,螺旋CT薄层扫描三维重建8例。CT扫描采用ElscientCTTwinFlash,常规横断面平扫,部分加冠状面扫描,13例加增强扫描。MRI扫描采用PhilipsT5-Ⅱ型0.5Tesla超导成像系统,标准头部正交线圈。常规SE序列,扫描方向为横断面、矢状面和冠状面,扫描范围由鞍上池至第二颈椎下缘水平,61例中55例患者进行增强扫描。结果:CT发现颅底骨质侵犯17例,MRI扫描发现颅底侵犯26例,其中6例MRI扫描发现斜坡、翼突基底部和蝶骨基底部早期的骨髓浸润,而CT检查未见有这些部位的骨质破坏,另外3例MRI见肿瘤沿三叉神经向颅内侵犯,而CT未见明确的卵圆孔破坏。结论:CT与MRI均可显示鼻咽癌通过破坏骨质侵犯颅底,也可以通过自然孔道进入颅内。MRI较CT对颅底骨质破坏的检出更敏感,MRI可以发现肿瘤沿三叉神经向颅内侵犯,而卵圆孔没有骨质破坏。MRI较CT可以更准确地界定肿瘤的侵犯范围;螺旋CT薄层三维重建,可以较为直观地显示病灶。

BACKGROUND &OBJECTIVE:With the g eneral using of computed tomog raphy(CT)and mag netic resonance imag ing(MRI ),it is important to determine which method is more sensitive in detecting the sk ull base encroachment in clinic.This articl e was desig ned to investig ate the dia g nostic value of CT and MRI in detecting the sk ull base erosion in nasopharyng eal carcinoma patients.METHODS :Sixty-one cases patholog ically pro ven as nasopharyng eal carcinoma were sele cted from Aug ust 1993to September 2001.three-dimensional reconstruction with spiral CT thin slices scan were p erformed in8cases.CT scan was performed with El scient CT Twin Flash;axial scan was parallel to the OM line routinely fro m soft palate to the suprasellar cist ern.There were 13cases with enhancement scan.MRI scan was performed by Philips T5-II super-conducting mag netic resonance imag ing system(0.5T).The standard quadrature head coil was used.Routine axial,sag ittal,and coronal imag e with SE sequences were obtained.Scanned field rang ed from the soft palate to t he suprasellar cistern.After plain sc an,enhanced scan was performed in 55of 61cases.RESULTS :MRI discovered the skull base encroa ched more precisely than CT,17cases by CT and 26cases by MRI,respectively.The early bone marrow infiltration was seen at cliv us,basilar pteryg oid,and basilar s phenoid in6cases by MRI scan while CT scan showe d no abnormal lesion at these sites.I n addition,MRI revealed nasopharyng eal carcinoma tissue infiltrated al ong the mandibular nerve(3cases )while CT scan showed no chang e of thes e structures.CONCLUSION:Both CT and MRI can reveal that the tum or encroaches on the skull base by either destroying the bony structure or br eaking throug h the natural foramen.MRI is more sensitive than CT in detecting th e skull base encroachment.MRI could reveal the early infiltration of the bone ma rrow and tumor infiltration along the man dibular nerve.MRI confirms the dime nsion of nasopharyng eal carcinoma more precisely than CT.The three dimension reconstructional spiral CT was dire cter in discovering the dimension of the tumor.