海洛因海绵状白质脑病影像学对比分析

Comparison of MRI, CT, TCD and SPECT in patients with spongiform leukoencephalopathy after inhaling heroin vapor

目的 对海洛因海绵状白质脑病患者的MRI、CT、单光子发射计算机体层摄影术 (singlephotonemissioncomputerizedtomography ,SPECT)脑显像与经颅多普勒超声 (transcranialDopplersonography,TCD)表现进行对比分析。方法 共观察 1 7例海洛因海绵状白质脑病患者 ,其中对 1 2例患者单行颅脑MRI ,2例单行CT ,3例同时行MRI和CT检查 ;9例行SPECT检查 ;1 1例行TCD检查 ,并设TCD对照组。结果 MRI或CT :全部患者幕上半球脑白质、小脑半球、内囊后肢及膝部、胼胝体压部及膝部 ,部分患者中脑、桥脑见双侧、对称性异常改变。 5例CT表现为上述白质区对称性低密度 ;1 5例MRI均表现为T1 WI呈低信号 ,T2 WI及水抑制成像呈高信号。SPECT :以白质为主的放射性稀疏或缺损 ,脑白质区扩大 ;灰质区亦存在不同程度的多发低供血灶 :颞叶 9例 ;顶叶 7例 ;小脑 7例 ;基底神经核 5例 ;枕叶 4例。TCD :收缩峰变尖 ,脑前循环与后循环舒张期血流速度 [分别为 (35 0± 9 7)cm/s,(2 3 4±5 2 )cm/s]均较对照组 [分别为 (43 2± 7 5)cm/s,(2 7 6± 5 0 )cm/s]显著降低 (P <0 0 1 ) ;脉动指数(分别为 1 0 4 0± 0 2 30 ,1 0 63± 0 331 )较对照组 (分别为 0 751± 0 0 92 ,0 70 8± 0 1 0 3)明显增高 (P <0 0 1 )。

Objective To compare the characteristics of MRI, CT, single photon emission computed tomography(SPECT) and transcranial Doppler sonography(TCD) in patients with spongiform leukoencephalopathy after inhaling heroin vapor. Methods Seventeen patients were investigated. MRI or CT was scanned in 17 patients, SPECT in 9 patients′ and TCD in 11 patients. Results MRI or CT: Brain MRI and CT revealed extensive symmetric white matter involvement of bilateral cerebral and cerebellar hemispheres and the brainstem.The lesions, which showed no contrast enhancement, were hypodense on CT and hypointense on T 1 weighted and hyperintense on T 2 weighted MRI. SPECT: The regional cerebral blood flows(rCBF) of white matter involvement on bilateral cerebral and cerebellar hemispheres was reduced obviously. The rCBF of temporal lobes, parietal lobes, occipital lobes, cerebellar hemispheres, and basal ganglion was reduced in varying degrees. TCD: The systolic peak became sharpened, and end diastolic flow velocity and mean flow velocity were reduced obviously and pulsatility index was increased markedly in patients with spongiform leukoencephalopathy after inhaling heroin vapor. Conclusion The characteristic manifestations of MRI and CT imaging may be regarded as the main foundation of diagnosing spongiform leukoencephalopathy after inhaling heroin vapor; SPECT and TCD can help comprehend the changes of hemodynamics of cerebral vessels and the degree of cerebral ischemia in patients with spongiform leukoencephalopathy after inhaling heroin vapor.