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BACKGROUND AND PURPOSE: Ischemic cerebrovascular disease is the most common brain disease with high morbidity and mortality has been hot and difficult medical session attention and study. Scholars at home and abroad imaging studies focused on acute ischemic cerebrovascular disease early after cerebral infarction or early diagnosis, imaging techniques, including magnetic resonance diffusion weighted imaging, perfusion-weighted imaging, CT perfusion imaging, Xe-CT and ECT. In recent years, with the development of multi-slice spiral CT technology, CT perfusion caused attention, super early in the incidence of ischemic cerebrovascular disease (6h within) the evaluation of ischemic brain tissue perfusion display the vacancy bloody lesion location and extent, and imaging confirmed the presence of IP; United brain CT angiography (CT angiography, CTA) can be visually shows the corresponding condition of the feeding artery. The cerebral infarction preliminary proposal of the concept and application of clinical significance. Decline in cerebral blood flow (cerebral blood flow, CBF) acute cerebral infarction occurred experiencing a period of change: The first is due to cerebral perfusion pressure decline caused cerebral hemodynamic abnormalities change; followed by cerebral circulation reserve force (cerebral circulation reserve the CCR) decompensated hypoperfusion caused neurons function changes; Finally, the CBF decreased more than cerebral metabolic reserve force (cerebral metabolism reserve, CMR) before irreversible neuron morphological changes that cerebral infarction. Called cerebral infarction prophase of the first two periods. Regional cerebral transient ischemic attack (transient ischemic attack, TIA) from the pathology as a recoverability ischemic penumbra (the ischemic penumbra IP), the TIA and IP in the infarct pre. The purpose of this study is to investigate the clinical value of CTA and CT perfusion imaging (multi-slice spiral CT perfusion imaging, MSCTPI) for the early diagnosis of cerebral infarction. MATERIALS AND METHODS: November 2004 to August 2006, a clinical diagnosis of acute ischemic cerebrovascular disease, 78 patients (male 51 cases, 27 females, aged 34 to 78 years, with an average age of 61 years) 16 slice spiral CT head and neck vascular imaging and brain perfusion imaging examination, the TIA group of 43 cases, 35 cases of acute cerebral infarction. The peak measuring brain region of interest of TIA patients the time (time to peak, TTP), cerebral blood flow (cerebral blood flow, CBF), cerebral blood volume (cerebral blood volume, CBV), mean transit time (mean transit time, MTT), and cerebral infarction pre-staging. The early staging criteria of cerebral infarction: Ⅰ 1 of, TTP extend MTT, rCBF and rCBV normal. Ⅰ 2 of, TTP and MTT extend, rCBF normal or slightly decreased, rCBV increased. Ⅱ 1 of extend the TTP and MTT, rCBF decline, rCBV increased. Ⅱ 2 TTP and MTT extend rCBF and rCBV decline. Cases of infarction onset time 26-68h. By perfusion analysis software to determine the area of ??hypoperfusion, combined with a the CT source of axial images defined in the parameter map two regions of interest (region of interest, ROI): 1. Low CBF and CBV infarct core, 2. Low CBF and the normal CBV IP. ROI absolute value of the parameters and the contralateral mirror measuring the corresponding ratio were calculated. All 78 patients CTA scan data is transmitted after a smooth reconstruction to ADW4.2 workstation. Horizontal axis surface image evaluation of wall plaques, Applied Surface Reconstruction (curved Curved planar reconstruction CPR) and maximum intensity projection method (maximum intensity projection, MIP) observed vascular overall shape. The application volume reconstruction method (volume rendering, VR) reconstruction of the brain before, during and after the 3,4-level branch of the artery. Restenosis rate calculated in accordance with the North American Symptomatic Carotid Endarterectomy Trial (NASCET) standard. SPSS12.0 statistical software, all data processing, check level of P <0.01. Results: TIA group: ① The MSCTPI found 33 cases with clinical corresponds to the abnormal perfusion performance, including TTP have significantly prolonged 33 Li, MTT have significantly prolonged 27 Li, CBF have low perfusion performance of 18 Li, CBV have low perfusion performance of there 19 cases. 10 cases of abnormal perfusion performance. According to the above cerebral infarction pre-staging on criteria to judge: I 1 6 cases, Ⅰ 2 of nine cases, Ⅱ 7 cases, Ⅱ 2 of 11 cases. In 33 patients, TTP ipsilateral average (12.83 ± 4.30) s, contralateral (10.48 ± 2.47) s, the difference was statistically significant (t = 1.642, p = 0.009). Ipsilateral and contralateral CBF, CBV, MTT showed no statistical significance. ② 43 patients CTA, found 57 carotid stenosis, 25 patients with different degrees of stenosis of the intracranial arteries. ③ 33 cases the perfusion abnormalities TIA patients had varying degrees of head and neck arteries narrow, 10 patients with normal perfusion patients found only one case of the internal carotid artery at the beginning of moderate stenosis and calcified plaque. Acute cerebral infarction group: (1) 35 cases of acute cerebral infarction patients the three cases MSCTPI examination showed hyperperfusion, 30 patients showed varying degrees of perfusion, two cases of normal perfusion. All patients infarct core, IP in terms of regional cerebral blood volume (regional cerebral blood volume, rCBV), regional cerebral blood flow (regional cerebral blood flow, rCBF) the relative and absolute statistically significant difference (p < 0.01), of all infarcted area ROI rCBF average ratio <0.23, IP-rCBF average ratio of> 0.29, while rCBF average ratio> 0.39, rCBV ratio> 0.99 are normal. 21 cases of patients with larger infarct volume (average of about 5cm 3-8cm 3 ) , MSCTPI discovered infarct corresponding significant hypoperfusion area, two cases found no obvious patients with perfusion abnormalities, infarct volume is small (3cm 3 -4cm 3 ). ② 35 patients with acute cerebral infarction patients CTA found that 51 of the internal carotid artery showed varying degrees of stenosis, 13 vertebral atherosclerosis mild stenosis. 25 cases of intracranial arteries found that there are different degrees of stenosis. Conclusion: ① MSCTPI TIA patients to provide valuable information on cerebral hemodynamics, CTA can effectively found cerebral artery and carotid artery stenosis. The ② TTP is the most sensitive parameter found the TIA cerebral perfusion abnormalities. The ③ MSCTPI combined with CTA can clear identification of acute cerebral infarction core and IP, to make a comprehensive assessment of TIA, cerebral blood flow perfusion and vascular lesions. ④ imaging studies of acute ischemic cerebrovascular disease in advance to cerebral infarction early has important clinical significance and application prospects.
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