Acute cerebral hemorrhage magnetic resonance diffusionweighted imaging毕业论文翻译.docx

1、Acute cerebral hemorrhage magnetic resonance diffusionweighted imaging毕业论文翻译 Acute cerebral hemorrhage magnetic resonance diffusion-weighted imaging Abstract Objective To investigate the acute cerebral hemorrhage, magnetic resonance diffusion-weighted imaging (DWI) in the performance of its mechanis

2、m. Methods of clinical symptoms after 12 h, expert DWI examination 17 cases of acute cerebral hemorrhage, the patients DWI and ADC maps were observed 17 cases of acute cerebral hemorrhage on DWI nine cases showed low signal for the central, peripheral irregular high signal; 6 cases showed homogeneou

3、s high signal for the central, peripheral, see the low signal, two cases of performance for high and low mixed signal when b = 0 base collection like the 11 cases showed low signal, of which six cases of low signal region can be seen intermingled with the high signal, six cases showed isointense sig

4、nal around see irregular ring of low signal on the ADC map 15 cases showed homogeneous low signal. conclusions combined with ADC maps and b = 0 the basis of acquisition like that DWI is able to make an accurate diagnosis of acute cerebral hemorrhage, Keywords magnetic resonance imaging, diffuse cere

5、bral hemorrhage diagnosis ABSTRACT ObjectiveTo investigate the manifestations and mechanism of acute intracerebral hemorrhage on diffusion weighted MR imaging (DWI). MethodsDWI was performed for patients with acute intracerebral hemorrhage (n = 17) within 12 hours after the onset of symptoms. Both t

6、he DWI and ADC map were analysed to investigate the manifestations and the mechanism of the disease. ResultsOn DWI, among the 17 patients, nine were found with low signal in the centre and irregular outer high signal, six with middle inhomogeneous high signal and surrounding low signal, and two with

7、 mixed signal. On the DWI (b = 0), obvious low signals were found in 11 patients of whom iso or high signals were also found in the low signal area in six patients, in isointensity with surrounding irregular low signal. Fifteen patients with inhomogeneous low signal were found on ADC map. Conclusion

8、Combined with ADC map and the DWI (b = 0), accurate diagnosis of acute intracerebral hemorrhage could be made by diffusion weighted MR imaging. KEY WORDS the diffusion of magnetic resonance imaging; cerebral hemorrhage, diagnosis Magnetic resonance diffusion-weighted imaging (DWI has been widely use

9、d in acute, the diagnosis of hyperacute cerebral infarction, about the essence of acute cerebral hemorrhage DWI performance of domestic, foreign and are rarely reported 1,2. Due to acute cerebral hemorrhage, and acute brain similar clinical symptoms of infarction, treatment is completely different,

10、and therefore very important to distinguish between the two. DWI manifestations of acute cerebral hemorrhage, were observed, and its mechanism are discussed. An object and method 1.1 General Information This group, 17 cases of acute cerebral hemorrhage, the patients in the clinical symptoms for 12 h

11、 within magnetic resonance (MR examination, and are experts in MR imaging 15 min after CT examination confirmed 11 cases were male and 6 females, aged 46 to 69 years old, average 58.7 years old. 1.2 the MR check DWI examination the Siemens 1.5 T whole body MR imaging system (Magnetom Sonata, Syngo t

12、he MR 2000B standard head coil. Scan parameters: TR = 3 of 100 ms, TE = 96 ms, slice thickness 5 mm, the interval of 1 mm, FOV = 230 mm 201 mm, matrix 128 128. DWI sequences selected three directions imaging (b = 0,1 000 s/mm2, the diffusion gradient were imposed on the level select and frequency en

13、coding and phase encoding direction, on-line to generate the trace DWI, map and trace ADC map can be directly measured in the ADC images regions of interest (ROI apparent diffusion coefficient (ADC. 1.3 CT examination Using the Siemens Sensation 16-slice spiral CT scanner. Scan parameters: 120 kV, 2

14、00 mA, slice thickness 10 mm, an interval of 10 mm, matrix 256 256. 2 results 2.1 CT manifestations of 17 cases of acute cerebral hemorrhage in the basal ganglia area, 10 cases in which the right side, left side of the seven cases. On CT showed a round or oval high-density, uniform density, CT value

15、 (75.1 + - 6.7Hu peripheral edema, and adjacent structures seen under pressure to shift. 2.2 DWI, performance On DWI, 9 cases showed low signal for the central, peripheral irregular high signal, six cases manifested as central heterogeneous high signal, the surrounding of the low signal performance

16、in the two cases of high and low mixed signals. The basis of acquisition b = 0 images, 11 cases showed low signal, of which six cases of low signal area seen intermingled with the high signal, six cases showed isointense signal, surrounded in an irregular low signal ring. On the ADC map, 15 cases sh

17、owed homogeneous low signal two cases the performance of high and low mixed signals, among which 12 cases seen in the peripheral irregular high signal, the mean ADC value within the hematoma (41.98 + -16.96 10-5 mm2 / s, and acute cerebral infarction area mean ADC value of another study, (45.07 + -1

18、1.13) 10-5 mm2 / s, the difference was not statistically significant (t = 1.053, P> 0.05 peripheral edema, the mean ADC value of (128.40 + -20.97 10-5 mm2 / s,. 3 to discuss Is generally believed that CT sensitivity to acute cerebral hemorrhage, is higher than MRI, conventional MR is difficult to

19、 diagnose bleeding within 24 h, thus the conventional CT is more commonly used for diagnosis of cerebral hemorrhage 3 However, with MR recognize the value of assessment of acute ischemic stroke and the popularity of the MR examination, whether the application of MR stroke suspected patients one-stop

20、 diagnosis become a focus of attention of neuroradiologists have to avoid the first CT scan to exclude hemorrhagic stroke MR examination to assess acute ischemic stroke has been shown that through the rational application of MR imaging techniques for the detection of different types of intracranial

21、hemorrhage, the value of MR and CT are quite than CT more sensitive, especially for the hard membrane, subarachnoid and intraventricular hemorrhage 4-6. On the assessed value of DWI for acute, hyperacute ischemic stroke has been very positive, but less on DWI, the diagnostic value of brain hemorrhag

22、e, and the number of cases involved rarely 1,7 is generally considered acute cerebral hemorrhage ADC values ​​decline, mainly as high signal on DWI, the proliferation of decline seen in a heterogeneous low-signal components of high signal may be related to contraction of blood clots rela

23、ted to the composition of the low signal generated by deoxyhemoglobin. DWI performance of bleeding in this study is not completely consistent with the literature, only six cases in DWI showed heterogeneous high signal on the ADC map showed low signal. patients showed the central low signal intensity

24、 on DWI, the surrounding ring or irregular high signal on the ADC map, expressed as the low signal of the central area, the surrounding ring of high signal. nine cases of bleeding volume less obvious low signal on DWI when b = 0, may be oxygenated Haemoglobin has been completely or most of the conve

25、rsion of deoxy-hemoglobin, low signal on DWI, not only with the spread of the decrease of the paramagnetic effect of deoxyhemoglobin. lesions surrounding high signal may be caused by bleeding around the brain tissue edema. also shows that the conversion of oxygenated hemoglobin to deoxygenated hemog

26、lobin in the acute stage of cerebral hemorrhage 1 cases of this article heterogeneous signal intensity on DWI performance, mixed signal on the ADC map, the lowest ADC value of .304 10 - 3 mm2 / s, while up to 1.052 10 -3 mm 2 / s, indicating that the rise of the local ADC values ​​may th

27、e bleeding area in the past existence of cerebral malacia related. Links in the free paper download the center gradient echo sequence using the flip readout gradient instead of 180 composite RF pulse echo, and therefore cause for the bleeding of paramagnetic highly sensitive to magnetic field inhomo

28、geneity. hematoma on the gradient echo sequence will result in low signal area, the range is significantly greater than conventional T2-weighted images. Studies have shown that conventional MR spin echo sequence with gradient echo sequence combined with MRI and CT for diagnosis of acute bleeding 8-1

29、1. MRI in determining the etiology of acute cerebral hemorrhage is superior to CT for cerebral arteriovenous malformations, aneurysms have a very important value. b = 0 DWI image (EPI T2 * WI has a gradient echo sequence sensitive features of bleeding, this study of 17 cases 11 cases of cerebral hem

30、orrhage was low signal, six cases of low signal ring. In addition, the EPI T2 * WI sequence scan time was significantly shorter than the gradient echo sequence, in theory, should be suitable for the diagnosis of acute cerebral hemorrhage, but the EPI T2 * WI, due to the low spatial resolution in the

31、 EPI T2 * WI, has been reported in the literature, the sensitivity of cerebral hemorrhage less than the gradient echo sequence 12 We believe that the apparent restlessness of the patient, consider using the EPI the T2 * WI sequence, the use of its high temporal resolution to remove the artifacts cau

32、sed by the activities of the assessment of cerebral hemorrhage. In addition, the application of gradient echo sequences or EPI T2 * WI, should also be recognized that this sequence itself some limitations, due to the paramagnetic effect is particularly sensitive around the posterior fossa, paranasal

33、 sinuses, or skull base near the obvious artifacts and the diagnosis of these parts of the bleeding should be especially careful to avoid false positive errors. This study also showed that the simple measurement of ADC values ​​can not directly identify the essence of acute cerebral hemorrhage and