Signal transducer and activator of transcription（STAT）is a unique protein family that binds to DNA,coupled with tyrosine phosphorylation signaling pathways,acting as a transcriptional regulator to mediate a variety ...Signal transducer and activator of transcription（STAT）is a unique protein family that binds to DNA,coupled with tyrosine phosphorylation signaling pathways,acting as a transcriptional regulator to mediate a variety of biological effects.Cerebral ischemia and reperfusion can activate STATs signaling pathway,but no studies have confirmed whether STAT activation can be verified by diffusion-weighted magnetic resonance imaging（DWI）in rats after cerebral ischemia/reperfusion.Here,we established a rat model of focal cerebral ischemia injury using the modified Longa method.DWI revealed hyperintensity in parts of the left hemisphere before reperfusion and a low apparent diffusion coefficient.STAT3 protein expression showed no significant change after reperfusion,but phosphorylated STAT3 expression began to increase after 30 minutes of reperfusion and peaked at 24 hours.Pearson correlation analysis showed that STAT3 activation was correlated positively with the relative apparent diffusion coefficient and negatively with the DWI abnormal signal area.These results indicate that DWI is a reliable representation of the infarct area and reflects STAT phosphorylation in rat brain following focal cerebral ischemia/reperfusion.展开更多
Purpose: This study aimed to examine whether the signal-to-noise ratio (SNR) could be increased by combining integrated slice-by-slice shimming (iShim) with a fat suppression (FS) method other than short-tau inversion...Purpose: This study aimed to examine whether the signal-to-noise ratio (SNR) could be increased by combining integrated slice-by-slice shimming (iShim) with a fat suppression (FS) method other than short-tau inversion recovery (STIR) in diffusion-weighted imaging (DWI) and q-space imaging (qsi). Methods: We acquired DWI images (b-values: 0 and nine steps from 400 to 10,000 s/mm2 for six axes) using a prototypical single-shot echo planar imaging sequence by combining two types of shimming (3D Shim and iShim) and two types of FS (STIR and water excitation [WE]) in 10 volunteers. In the DWI study, the SNR for each b-value, FS effect in the b0 image, and distortion in the added image (b0 - b10,000) were evaluated for the above-mentioned four imaging methods. qsi involved original DWI images. In the qsi study, the SNR was evaluated. Results: With regard to both 3D Shim and iShim, the SNRs were significantly higher when using WE than when using STIR in b0 - b900 images (p Conclusion: The combination of iShim and WE has a high SNR on qsi.展开更多
目的:研究急性单发脑梗死患者首次磁共振扩散加权成像(DWI)病灶信号强度在急性脑梗死分期中的应用价值,并探讨病灶信号均质度对评估患者入院病情严重程度的价值。方法:回顾性对符合入选条件的177例前循环急性脑梗死患者,通过测得整体病...目的:研究急性单发脑梗死患者首次磁共振扩散加权成像(DWI)病灶信号强度在急性脑梗死分期中的应用价值,并探讨病灶信号均质度对评估患者入院病情严重程度的价值。方法:回顾性对符合入选条件的177例前循环急性脑梗死患者,通过测得整体病灶相对信号强度(relative signal intensity,rSI)作为观察指标,统计分析超急性期、急性期和亚急性早期3组之间病灶rSI是否存在差异性;分析患者总体症状发作与首次急诊入院DWI检查的间隔时间与相应rSI的相关性;采用联合rSI的综合评分法对病灶均质与非均质进行评定,把病灶信号均质组与非均质组相应的入院NIHSS评分高低四组总体分布进行比较,并进行统计学分析。结果:177例中超急性期组24例、急性期组78例及亚急性早期组75例;轻度卒中组90例、中度卒中组66例、中-重度卒中组14例及重度卒中组7例。超急性脑梗死组rSI(1.573±0.238)、急性脑梗死组rSI(1.751±0.227)及亚急性早期脑梗死组rSI(1.943±0.309),三者相互之间均有统计学差异,所有P<0.01;177例rSI与相应的症状发作与首次急诊入院DWI检查的间隔时间呈正相关(r=0.553,P<0.01);信号均质病灶组103例,信号非均质病灶组74例,两组在入院NIHSS评分高低组别总体分布有统计学意义(P<0.05),且均质组和非均质病灶组病情程度分组总体概率分布不同,均质组中轻度组出现频率高于非均质组,非均质组中中度组出现的频率高于均质组。结论:首次DWI成像的对前循环单发急性脑梗死病灶信号强度测量,有利于总体上急性脑梗死超急性期、急性期及亚急性早期的临床分期;非均质病灶患者总体上较均质病灶患者的临床病情严重程度为重,病灶均质度判定对评估临床病情严重趋势具有一定价值。展开更多
背景与目的:背景抑制扩散加权成像(diffusion-weighted whole-body imaging with background body signal suppression,DWIBS)是一种可用于全身检查的MR成像技术,可以较好地显示淋巴结及骨骼系统病变,其成像效果与PET类似。本研究旨在探...背景与目的:背景抑制扩散加权成像(diffusion-weighted whole-body imaging with background body signal suppression,DWIBS)是一种可用于全身检查的MR成像技术,可以较好地显示淋巴结及骨骼系统病变,其成像效果与PET类似。本研究旨在探讨DWIBS与核素骨扫描成像在骨转移性病变诊断中的临床应用价值。方法:36例经手术或穿刺病理证实为恶性肿瘤的患者行DWIBS及核素骨扫描检查,比较两者检出骨转移的情况,采用χ2检验,P<0.05为差异有统计学意义。结果:36例恶性肿瘤患者中,30例(共165处)发生骨转移,其中DWIBS检出26例(143处),核素骨扫描检出23例(132处),两者在检出骨转移方面差异无统计学意义(χ2=1.002,P=0.506)。DWIBS及核素骨扫描诊断骨转移的灵敏度、阳性预测值、准确度较为接近,分别为86.7%、96.3%、86.1%和76.7%、88.5%、72.2%;DWIBS诊断骨转移的特异度、阴性预测值高于核素骨扫描,分别为83.3%、55.6%和50.0%、30.0%。分析DWIBS和核素骨扫描检出骨转移的部位,两者的检出率分别为86.7%(143/165)、80.0%(132/165),差异无统计学意义(χ2=2.640,P=0.104);但DWIBS在检出骨盆及四肢长骨转移方面优于核素骨扫描,且两者差异均有统计学意义(χ2=6.783和7.636,P=0.023和0.016)。结论:运用DWIBS扫描技术可有效检出骨转移性病灶,且与核素骨扫描具有较好的一致性,有望在临床上推广应用。展开更多
文摘Signal transducer and activator of transcription（STAT）is a unique protein family that binds to DNA,coupled with tyrosine phosphorylation signaling pathways,acting as a transcriptional regulator to mediate a variety of biological effects.Cerebral ischemia and reperfusion can activate STATs signaling pathway,but no studies have confirmed whether STAT activation can be verified by diffusion-weighted magnetic resonance imaging（DWI）in rats after cerebral ischemia/reperfusion.Here,we established a rat model of focal cerebral ischemia injury using the modified Longa method.DWI revealed hyperintensity in parts of the left hemisphere before reperfusion and a low apparent diffusion coefficient.STAT3 protein expression showed no significant change after reperfusion,but phosphorylated STAT3 expression began to increase after 30 minutes of reperfusion and peaked at 24 hours.Pearson correlation analysis showed that STAT3 activation was correlated positively with the relative apparent diffusion coefficient and negatively with the DWI abnormal signal area.These results indicate that DWI is a reliable representation of the infarct area and reflects STAT phosphorylation in rat brain following focal cerebral ischemia/reperfusion.
文摘Purpose: This study aimed to examine whether the signal-to-noise ratio (SNR) could be increased by combining integrated slice-by-slice shimming (iShim) with a fat suppression (FS) method other than short-tau inversion recovery (STIR) in diffusion-weighted imaging (DWI) and q-space imaging (qsi). Methods: We acquired DWI images (b-values: 0 and nine steps from 400 to 10,000 s/mm2 for six axes) using a prototypical single-shot echo planar imaging sequence by combining two types of shimming (3D Shim and iShim) and two types of FS (STIR and water excitation [WE]) in 10 volunteers. In the DWI study, the SNR for each b-value, FS effect in the b0 image, and distortion in the added image (b0 - b10,000) were evaluated for the above-mentioned four imaging methods. qsi involved original DWI images. In the qsi study, the SNR was evaluated. Results: With regard to both 3D Shim and iShim, the SNRs were significantly higher when using WE than when using STIR in b0 - b900 images (p Conclusion: The combination of iShim and WE has a high SNR on qsi.
文摘目的:研究急性单发脑梗死患者首次磁共振扩散加权成像(DWI)病灶信号强度在急性脑梗死分期中的应用价值,并探讨病灶信号均质度对评估患者入院病情严重程度的价值。方法:回顾性对符合入选条件的177例前循环急性脑梗死患者,通过测得整体病灶相对信号强度(relative signal intensity,rSI)作为观察指标,统计分析超急性期、急性期和亚急性早期3组之间病灶rSI是否存在差异性;分析患者总体症状发作与首次急诊入院DWI检查的间隔时间与相应rSI的相关性;采用联合rSI的综合评分法对病灶均质与非均质进行评定,把病灶信号均质组与非均质组相应的入院NIHSS评分高低四组总体分布进行比较,并进行统计学分析。结果:177例中超急性期组24例、急性期组78例及亚急性早期组75例;轻度卒中组90例、中度卒中组66例、中-重度卒中组14例及重度卒中组7例。超急性脑梗死组rSI(1.573±0.238)、急性脑梗死组rSI(1.751±0.227)及亚急性早期脑梗死组rSI(1.943±0.309),三者相互之间均有统计学差异,所有P<0.01;177例rSI与相应的症状发作与首次急诊入院DWI检查的间隔时间呈正相关(r=0.553,P<0.01);信号均质病灶组103例,信号非均质病灶组74例,两组在入院NIHSS评分高低组别总体分布有统计学意义(P<0.05),且均质组和非均质病灶组病情程度分组总体概率分布不同,均质组中轻度组出现频率高于非均质组,非均质组中中度组出现的频率高于均质组。结论:首次DWI成像的对前循环单发急性脑梗死病灶信号强度测量,有利于总体上急性脑梗死超急性期、急性期及亚急性早期的临床分期;非均质病灶患者总体上较均质病灶患者的临床病情严重程度为重,病灶均质度判定对评估临床病情严重趋势具有一定价值。
文摘背景与目的:背景抑制扩散加权成像(diffusion-weighted whole-body imaging with background body signal suppression,DWIBS)是一种可用于全身检查的MR成像技术,可以较好地显示淋巴结及骨骼系统病变,其成像效果与PET类似。本研究旨在探讨DWIBS与核素骨扫描成像在骨转移性病变诊断中的临床应用价值。方法:36例经手术或穿刺病理证实为恶性肿瘤的患者行DWIBS及核素骨扫描检查,比较两者检出骨转移的情况,采用χ2检验,P<0.05为差异有统计学意义。结果:36例恶性肿瘤患者中,30例(共165处)发生骨转移,其中DWIBS检出26例(143处),核素骨扫描检出23例(132处),两者在检出骨转移方面差异无统计学意义(χ2=1.002,P=0.506)。DWIBS及核素骨扫描诊断骨转移的灵敏度、阳性预测值、准确度较为接近,分别为86.7%、96.3%、86.1%和76.7%、88.5%、72.2%;DWIBS诊断骨转移的特异度、阴性预测值高于核素骨扫描,分别为83.3%、55.6%和50.0%、30.0%。分析DWIBS和核素骨扫描检出骨转移的部位,两者的检出率分别为86.7%(143/165)、80.0%(132/165),差异无统计学意义(χ2=2.640,P=0.104);但DWIBS在检出骨盆及四肢长骨转移方面优于核素骨扫描,且两者差异均有统计学意义(χ2=6.783和7.636,P=0.023和0.016)。结论:运用DWIBS扫描技术可有效检出骨转移性病灶,且与核素骨扫描具有较好的一致性,有望在临床上推广应用。
