胰腺癌的ADC值和患者病理参数的关系研究

目的探讨胰腺癌高场磁共振扩散成像(DWI)表观扩散系数(ADC)值与纤维化含量、成纤维细胞活化蛋白(FAP)表达评分的相关性。方法对28例胰腺癌患者进行高场磁共振扩散加权成像扫面,每例患者取癌区与非癌区样本各一处,共取56处样本,使用单一层面发选取样本ROC并对ADC值进行测量。取28例患者经病理学检验证实的蜡块进行Masson染色,对FAP免疫组化染色,对ADC值与纤维化含量以及成纤维细胞活化蛋白表达评分之间的相关性进行Pearson相关分析。结果 ADC测量结果发现,患者胰腺癌区ADC值为(1.159±0.210)×10-3mm2/s,非胰腺癌区ADC值为(1.543±0.294)×10-3mm2/s,两项数据相比具有统计学差异。选取的28个癌区蜡块经病理学检验均为胰腺导管腺癌,检测其分化程度发现其中5例低分化,4例中-低分化,12例中分化,3例高-中分化,4例高分化,纤维化含量检测结果发现癌区纤维化含量最小值为20%,最大值为87%。FAP评分结果中12例5分,8例4分,3例3分,3例2分以及2例1分。相关性分析结果发现胰腺癌ADC值与纤维化含量之间呈负相关关系,但经统计学检验并未发现统计学意义,中-高分化的胰腺癌患者ADC与纤维化含量呈负相关关系,此数据具有统计学意义,而胰腺癌ADC值与成纤维细胞活化蛋白表达评分之间同样为负相关关系,P0.05,数据具有统计学意义。结论胰腺癌高场磁共振扩散呈现表观扩散系数与纤维化含量以及成纤维细胞活化蛋白表达评分之间存在负相关关系,DWI可成为临床定量描述胰腺癌患者病理参数的有效工具。     

鼻咽癌磁共振灌注定量参数及ADC值与T分期的关系

目的：探讨鼻咽癌（NPC）磁共振灌注成像（PWI）定量参数及扩散加权成像（DWI）参数ADC 值与T 分期之间的相关性。方法：对94例NPC初治患者行PWI、DWI和T分期,分析PWI参数及ADC值与T分期之间的相关性,比较高低T分期NPC之间各 MR参数值的差异。结果：T 分期分别与 Ktrans （r＝0．226,P＝0．029）和 Ve （r＝0．553,P＝0．000）呈正相关,与Kep呈负相关（r＝－0．350,P＝0．001）。未发现T 分期与 fPV（r＝－0．122,P＝0．240）及 ADC 值（r＝－0．056,P＝0．592）之间存在线性相关。Ktrans、Kep和 Ve 值在 Thigh组（T3和 T4期 NPC）分别为（0．386±0．171）、（1．333±0．436）min－1和（0．302±0．107）,在 Tlow组（T1和 T2期 NPC）分别为（0．313±0．115）min－1、（1．552±0．472）min－1和0．219±0．102,两组间的差异有统计学意义。fPV和ADC值在Thigh组分别为（0．017±0．021）和（0．935±0．144）×10－3 s／mm2,在Tlow组分别为（0．019±0．018）和（0．950±0．196）×10－3 s／mm2,两组间的差异无统计学意义。与Ktrans和Kep值相比,Ve 值在判别Thigh组和Tlow组上诊断效能最大,其敏感性为91．8％、特异性为63．2％。结论：PWI定量参数可以反映不同T分期NPC在内部微循环灌注上的差异,而ADC值难以区分不同T分期NPC之间在水分子扩散方面的差别。     

颈动脉狭窄致脑低灌注损伤多模态MRI

目的：探讨颈动脉狭窄程度与颈内动脉血流动力学参数及相关脑区ADC值变化的关系。方法：27例患者经磁共振血管成像（MRA）证实有中度以上颈动脉狭窄。所有患者行颅脑常规 MRI、MRA和DWI检查,并采用血流定量测量（QFlow）和彩色多普勒超声（CDFI）对颈内动脉的血流动力学参数进行分析。对 QFlow技术与CDFI 测量的血流参数（血流量、平均流速、峰值流速及管腔面积）及其与颈动脉狭窄程度及相关脑区的表观扩散系数值（ADC ）之间的相关性行非参数检验。结果：①QFlow技术与CDFI测量的血流量和平均流速呈中度正相关（r＝0．695,P＜0．01;r＝0．795,P＜0．01）,峰值流速和管腔面积呈低度正相关（r＝0．453,P＜0．01;r＝0．573,P＜0．01）。②颈动脉狭窄程度与 QFlow 技术测量的颈内动脉流量呈低度负相关（r＝－0．467,P＜0．01）,与侧脑室旁前部和额叶白质的 ADC 值呈低度正相关（r＝0．373,P＜0．01;r＝0．372,P＜0．01）。③侧脑室旁前部和额叶白质的ADC 值与 QFlow 技术测量的颈内动脉流量分别呈中度和低度负相关（r＝－0．624,P＜0．01;r＝－0．533,P＜0．01）。结论：多模态 MRI能显示颈动脉狭窄所致的颈内动脉血流量减低及供血脑区的低灌注损伤,QFlow技术能较准确评价颈内动脉血流动力学变化。     

脑星形细胞瘤表观扩散系数的应用价值

目的 评估表观扩散系数（ADC）鉴别星形细胞瘤不同肿瘤组织及与细胞密度、病理分级的相关性。资料与方法 采用Siemens1．5T超导型磁共振系统,对48例星形细胞瘤术前行常规MRI及扩散加权成像（DWI）,其中Ⅰ、Ⅱ级23例,Ⅲ、Ⅳ级25例。分别计算不同肿瘤组织的ADC值。病理标本行HE染色,采用ImageJ1．33j分析每一标本的肿瘤细胞密度。用SPSS11．0对资料进行处理。结果 星形细胞瘤不同肿瘤组织间及与正常脑实质的ADC值差异具有统计学意义（P〈0．001）;非强化的肿瘤实质与瘤周水肿区ADC值差异无统计学意义（P〉0．05）。星形细胞瘤病理分级与强化肿瘤实质ADC值呈负相关,rs=-0．641（P〈0．001）;强化肿瘤实质的ADC值与肿瘤细胞密度呈负相关,r=-0．643（P〈0．001）。结论 星形细胞瘤ADC值能鉴别不同肿瘤组织,有助于评价肿瘤细胞密度及病理分级。     

MRI小视野IVIM-DWI技术对鼻咽癌分期的初步探讨

目的：探讨 MRI 小视野基于体素内不相干运动（IVIM）扩散加权成像在鼻咽癌分期中的应用。方法：搜集经病理证实的53例未分化非角化型鼻咽癌首诊患者,并对患者进行分期（中国2008分期）,治疗前行 MRI 常规序列及小视野 IVIM-DWI 序列扫描。结果：ADCstand 值、ADCslow 值及 ADCfast 值在不同 T 分期之间存在显著差异。ADCslow 值在不同 N分期之间存在显著差异（P ＜0．05）。T 分期与 ADCstand 值（r ＝－0．580,P ＝0．000）及 ADCslow 值（r ＝－0．468,P ＝0．000）呈负相关,与 ADCfast 值（r＝0．406,P ＝0．000）呈正相关。N 分期与 ADCslow 值呈负相关（r ＝－0．502,P ＝0．000）。结论：小视野 IVIM-DWI 参数可能对鼻咽癌 T、N 分期具有一定的指导意义。     

磁共振成像T1值、T2值和ADC值与肝脏纤维化模型病理评分分级纤维化分期诊断结果相关性研究

目的：探讨磁共振成像T1值、T2值、ADC值对肝脏纤维化病理评分分级纤维化分期诊断的价值和意义。方法：将大白兔分为正常对照组（4只）和肝脏纤维化模型组（13只）,分别对其进行常规MR扫描,测量肝脏组织T1值和T2值;磁共振弥散加权成像扫描（MR-DWI）,测量肝脏组织表观扩散系数（ADC值）。取肝脏组织标本做常规HE染色和网状纤维染色（Gomoris法）,以病理组织学评分分级和纤维化分期诊断结果为标准,研究分析T1值、T2值和ADC值在肝脏纤维化不同评分分级和纤维化分期间的变化情况;采用统计学相关分析法研究T1值、T2值和ADC值在与病理积分、评分分级和纤维化分期诊断结果之问的相关性。统计学分析采用SPSS13．0,单相分析法,P〈0．05为差异有统计学意义。结果：磁共振成像T1值、T2值、ADC值测量结果在对照组和不同评分分级和纤维化分期间的差异性具有显著的统计学意义（P〈0．05）;在肝脏纤维化模型组中T1值和T2值明显高于对照组,且随着评分分级和纤维化分期的增加而逐渐增加;肝脏纤维化模型组中ADC值明显低于对照组,随着评分分级和纤维化分期的增加降低越显著。相关分析结果表明T2值与病理积分、评分分级和纤维化分期诊断结果之间呈显著正相关性（P〈0．01）;ADC值与病理积分、评分分级和纤维化分期诊断结果之间表现显著负相关性（P〈0．01）。结论：在肝脏发生纤维化时,定量检测磁共振成像中的T1值、T2值和ADC值,能够评估肝脏纤维化病理评分分级和纤维化分期,作为非损伤性检查方法的磁共振成像可以用于临床肝脏纤维化定量诊断。     

DWI对前列腺癌疗效监测及ADC值与PSA相关性研究

目的：探讨前列腺癌（PC）患者治疗前后扩散加权成像（DWI）表现及表观扩散系数（ADC）值与前列腺特异性抗原（PSA）的相关性,从而以ADC值为定量分析指标,将DWI用于PC疗效的监测与评估。方法：48例经病理证实的PC患者均行内分泌治疗,其中12例行去势手术。分别在患者治疗前及治疗后30天行常规MRI及DWI检查,测量其治疗前后的ADC值和血清PSA水平,并对其进行相关性分析。结果：48例PC患者治疗前病灶ADC值为（0．778±0．108）×10^-3mm2／s,PSA值为（28．055±28．880）μg／L;治疗后病灶ADC值显著升高为（1．068±0．187）×10。mm。／S（P〈o．05）,PSA值显著降低为（6．265士13．203）μg／L（P〈0．05）;Pearson相关分析结果显示PC患者治疗前后ADC值与PSA均呈负相关（r=-0．677,P=0．001;r=-0．644,P=0．00）。结论：PC患者内分泌治疗后ADC值升高,与PSA水平呈负相关,DWI有望连续、定量、便捷地监测和评估PC疗效。     

多b值DWI对艾滋病家庭孤儿基底节扩散差异的研究

＿目的：探讨单指数模型和拉伸指数模型下多b值扩散加权成像（DWI）对 HIV阳性的诊断价值。方法：23名来自艾滋病家庭青少年孤儿,其中15例 HIV阳性感染者、8例 HIV阴性健康者。对所有研究对象行脑部多b 值（0、50、150、200、400、600、800s／mm2）DWI检查。利用单指数模型和拉伸指数模型拟合出脑部基底节区表观扩散系数（ADC）、分布扩散系数（DDC）、异质性指数（α）后行统计学分析。结果：两种模型均能较好描述出多b值DWI中体素内信号强度随b值增加而递减的特征;HIV阳性感染者左侧基底节区α值（0．848±0．068）较阴性健康者（0．923±0．050）明显下降（t＝－2．749,P＝0．012）,两组右侧基底节区α值差异无统计学意义（P＞0．05）。两组间DDC值和ADC值差异均无统计学意义（P均＞0．05）。各组基底节区DDC值与ADC值之间均呈正相关性（HIV 阳性感染者基底节区：左侧r＝0．770,P＝0．001,右侧r＝0．832,P＝0．000;HIV 阴性健康者基底节区：左侧r＝0．878,P＝0．004,右侧r＝0．927,P＝0．001）。结论：拉伸指数模型DWI中的α值有可能作为评价指标来鉴别HIV阳性和HIV阴性,对HIV阳性的诊断提供有价值的参考。     

星形细胞瘤瘤周水肿ADC值与MMP-9表达的相关性研究

目的探讨脑星形细胞瘤瘤周水肿表观扩散系数（ADC）值与基质金属蛋白酶（MMP-9）表达的关系。资料与方法对34例星形细胞瘤患者术前行常规MRI及扩散加权成像（DWI）,分别计算邻近、远离水肿区的ADC值。术后进行MMP-9免疫组织化学染色,并分析其表达程度与邻近、远离水肿区ADC值及病理分级的相关性。结果星形细胞瘤MMP-9表达与邻近、远离水肿区的ADC值及病理分级间的差异具有统计学意义（P〈0．05、0．001）。邻近、远离水肿区的ADC值与MMP-9表达均呈显著正相关,rs=0．750、0．800（P〈0．001）。结论星形细胞瘤瘤周水肿ADC值与MMP-9表达显著相关,测定瘤周水肿的ADC值,有助于预测星形细胞瘤的MMP-9表达。     

3.0T磁共振多b值DWI在鼻咽癌N分期中的应用

＿目的：探讨3．0T磁共振多b值扩散加权成像（DWI）评价鼻咽癌（NPC）颈部淋巴结转移的价值。方法：对45例经病理活检证实的NPC及15例良性淋巴结增大患者行常规 MR及多b值DWI（b＝600、800、1000s／mm2）检查。测量NPC、颈部转移性淋巴结及良性淋巴结不同 b 值的 ADC 值,采用 SPSS 1 3．0统计软件包对所测数据进行统计学分析。结果：NPC与转移性淋巴结的 ADC 值比较差异无统计学意义（t600＝－1．623,t800＝－0．742,t1000＝－1．684,P 均＞0．05）,而转移性淋巴结与良性淋巴结的ADC值比较差异有统计学意义（t600＝－3．623,t800＝－5．152,t1000＝－5．807,P均＜0．05）。b值为800s／mm2时ADC值对良恶性淋巴结鉴别能力最佳,截断值为0．938×10－3mm2／s。结论：3．0T MR-DWI有助于诊断NPC转移性淋巴结,对提高鼻咽癌N分期有重要作用。b值为800s／mm2时DWI对良恶性淋巴结鉴别诊断能力最佳。     

3.0 T MR动态增强扫描定量分析诊断前列腺癌的初步研究

目的 探讨3.0 T MR动态增强扫描(DCE-MRI)定量分析诊断前列腺癌的可行性,并评价定量参数转运常数(Ktrans)、血管外细胞外间隙体积百分数(Ve)及速率常数(kep)与Gleason评分及前列腺特异性抗原(PSA)水平的相关性.方法 行前列腺DCE-MRI检查并经穿刺活检证实的38例患者,在Ktrans、Ve及kep参数图上取ROI测量前列腺相应部位的Ktrans、Ve及kep值.对前列腺癌区、外周带非癌区和中央腺体非癌区的参数值行方差分析,并采用Pearson相关分析检验各参数与Gleason评分、PSA水平的相关性.结果 前列腺癌区的Ktrans、Ve 、kep值分别为(0.35±0.26)/min、(0.185±0.080)、(1.42±0.53)/min,外周带非癌区则分别为(0.07±0.05)/min、(0.040±0.024)、(0.50±0.18)/min,中央腺体非癌区则分别为(0.19±0.06)/min、(0.161±0.062)、(0.94±0.25)/min,各参数值差异均有统计学意义(F值分别为16.267、44.084、36.095,P值均＜0.01),前列腺癌区的Ktrans、Ve及kep值均与Gleason评分、PSA水平无显著相关性(r值分别为0.279、0.069、0.109、-0.175、-0.067和0.137,P值均＞0.05).结论 DCE-MRI定量参数诊断前列腺癌具有可行性,有助于鉴别前列腺癌和良性前列腺病变.

Abstract：

Objectives To investigate the feasibility of the quantitative analysis parameters of dynamic contrast-enhanced MRI (DCE-MRI) in the diagnosis of prostate cancer and to correlate Ktrans, Ve and kep with histological grade (Gleason score) and serum prostate specific antigen (PSA). Methods MR examinations were performed in 38 patients confirmed by biopsy. ROI were drawn on areas of cancerous foci,noncancerous foci in the peripheral zone and central gland to measure the values of Krans, Ve and kep. The values of the three parameters in different tissue were compared with ANOVA. The correlations between the pharmacokinetic parameters and Gleason score, PSA were assessed with Pearson correlation. Results The Ktrans, Ve, kep values of cancerous foci were (0. 35 ± 0. 26 )/min, ( 0. 185 ± 0. 080 ), ( 1.42 ± 0. 53 )/min,respectively, while (0. 07 ± 0. 05 )/min, ( 0. 040 ± 0. 024 ), (0. 50 ± 0. 18 )/min for noncancerous foci in the peripheral zone and (0. 19 ±0. 06)/min, (0. 161 ± 0. 062), (0. 94 ±0. 25) /min for noncancerous foci in the central gland, respectively. The differences between the three parameters of cancerous foci,noncancerous foci in the peripheral zone and central gland were statistically significant ( F = 16. 267,44. 084, 36. 095, respectively; P ＜ 0. 01 ). No significant correlations were found between any parameter and either Gleason score or PSA (r =0. 279,0.069, 0. 109, -0. 175, -0.067,0. 137, respectively;P ＞0. 05). Conclusion Quantitative analysis parameters of DCE-MRI are feasible in diagnosing prostate cancer. They may be useful in differentiating prostate cancer from benign prostatic diseases.     

Apparent diffusion coefficient in pancreatic cancer: characterization and histopathological correlations

PURPOSE: To clarify the components primarily responsible for diffusion abnormalities in pancreatic cancerous tissue. MATERIALS AND METHODS: Subjects comprised 10 patients with surgically confirmed pancreatic cancer. Diffusion-weighted (DW) echo-planar imaging (b value = 0, 500 s/mm(2)) was employed to calculate the apparent diffusion coefficient (ADC). ADC values of cancer and noncancerous tissue were calculated. Furthermore, ADC values of the cancer were compared with histopathological results. RESULTS: The mean (+/-standard deviation) ADC value was significantly lower for tumor (1.27 +/- 0.52 x 10(-3) mm(2)/s) than for noncancerous tissue (1.90 +/- 0.41 x 10(-3) mm(2)/s, P < 0.05). Histopathological examination showed similar proportions of fibrotic area, cellular component, necrosis, and mucin in each case. Regarding the density of fibrosis in cancer, three cases were classified in the loose fibrosis group and the remaining seven cases were classified in the dense fibrosis group. The mean ADC value was significantly higher in the loose fibrosis group (1.88 +/- 0.39 x 10(-3) mm(2)/s) than in the dense fibrosis group (1.01 +/- 0.29 x 10(-3) mm(2)/s, P < 0.05). In quantitative analysis, ADC correlated well with the proportion of collagenous fibers (r = -0.87, P < 0.05). CONCLUSION: Collagenous fibers may be responsible for diffusion abnormalities in pancreatic cancer.     

Diffusion-weighted MRI of the pancreas: correlation with secretin endoscopic pancreatic function test (ePFT)

RATIONALE AND OBJECTIVES: To evaluate the correlation between apparent diffusion coefficient (ADC) values of the pancreas on diffusion-weighted imaging (DWI) and pancreatic exocrine function determined by HCO(3) concentration in the secretin endoscopic pancreatic function test (ePFT). MATERIALS AND METHODS: Mean ADC values derived from 10 different points of the pancreatic gland on DWI were reviewed in 14 patients with normal (peak HCO(3) >/=80 mEq/L) and 14 patients with abnormal (peak HCO(3) <80 mEq/L) ePFT results. Magnetic resonance cholangiopancreatography (MRCP) images of the same patients were evaluated for the diagnosis of chronic pancreatitis. Correlation between ADC values and HCO(3) concentration as well as Cambridge scores in MRCP was performed using Spearman's correlation test. RESULTS: Mean ADC value of the pancreas was 1.52 +/- 0.13 x 10(-3) mm(2)/s in patients with abnormal ePFT results and 1.78 +/- 0.07 x 10(-3) mm(2)/s in the normal group. There was a significant statistical difference between the ADC values of the pancreas in the two groups (P < .0001). There was also a statistically significant correlation between HCO(3) level and ADC value of the pancreas in the study patients (r = 0.771, P < .0001). Morphologic changes of the pancreas according to the Cambridge classification were also well correlated with the mean ADC values (r = -0.763, P < .0001). CONCLUSIONS: Strong correlation between ADC value and pancreatic exocrine function as well as Cambridge score for chronic pancreatitis exists. Further studies are needed to determine the cut off ADC value for chronic pancreatitis.     

直肠癌扩散加权成像表观扩散系数值与预后因子的相关性

目的：探讨直肠癌扩散加权成像(DWI)表观扩散系数(ADC)值与预后因子的相关性。方法收集经术后病理确诊直肠癌的患者55例,术前行盆腔常规MRI及DWI检查,测量肿瘤平均ADC值。根据淋巴结转移状态分为有、无淋巴结转移2组;依据表皮生长因子受体(EGFR)表达水平的高低将其分为阴性、弱阳性、阳性和强阳性4组。分别探讨淋巴结不同转移状态、EGFR 不同表达水平与病灶 ADC值的相关性。结果55例直肠癌病灶中,有淋巴结转移的13例,EGFR的阳性表达率为67.2%。有、无淋巴结转移组病灶平均 ADC值之间比较无显著性差异(P=0.342)。EGFR表达阴性、弱阳性、阳性和强阳性组分别为18例、15例、12例和10例。EGFR表达水平不同组间病灶平均 ADC值比较无显著性差异(P=0.412)。病灶平均 ADC 值与淋巴结转移状态、EGFR表达水平无明确相关性(r分别为0.183、-0.324,P 值均>0.05)。结论 DWI 的 ADC 值目前尚不能为直肠癌预后评估及个体化治疗方案的制订提供有价值的临床信息,有待于进一步研究。     

~1H-MRS与DWI在骨质疏松症中的初步应用

目的 探讨绝经后女性腰椎骨髓脂肪分数(fat fraction,FF)、表观扩散系数(apparent diffusion coefficient,ADC)值与骨密度(bone mineral densities,BMD)的关系.资料与方法 将行腰椎双能量X线吸收测定(dual X-rayabsorptionmetry,DXA)的60例绝经后女性根据T值分为3组:骨质正常组(T>-1.0)20例,骨质减少组(T=-1.0～-2.5)20例,骨质疏松组(T<-2.5)20例.所有研究对象均行氢质子磁共振波谱分析(~1H MR spectroscopy,~1H-MRS)、MR扩散加权成像(diffusion weighted imaging,DWI),分别测定L_3椎体FF和ADC值.采用组间t检验对不同骨质组间FF、ADC值差异进行统计学分析.采用Pearson相关分析3组间FF、ADC值与BMD的相关性. 结果骨质疏松组脂肪含量[(59.1±8.8)%,P=0.003]与骨质减少组脂肪含量[(54±7.6)%,P=0.039]均比骨质正常组[(49±9.1)%]高.骨质疏松组比骨质减少组椎体脂肪含量高(P=0.045).椎体骨髓ADC值与T值无相关性.所有绝经后女性患者FF值与T值呈负相关(r=-0.46,P<0.01),与ADC值间呈轻度负相关(r=-0.25,P<0.05),但骨质疏松组中FF值与ADC值间呈较明显负相关(r=-0.72,P<0.01).ADC值与T值无相关性(r=0.315,P>0.05).结论 绝经女性椎体骨髓脂肪含量随着BMD的减小而增大.MRS可作为BMD检查的辅助手段.MRS与DWI可以无创性了解骨质疏松症患者骨髓的生理、病理变化,单纯DWI并不能反映BMD的改变.     

3.0T动态增强磁共振对前列腺癌的定量分析研究

目的：探讨3．0T磁共振动态增强（DCE-MRI）定量分析对前列腺癌的诊断价值,并评价Ktrans与Gleason评分的相关性。方法：回顾性分析40例经病理证实的前列腺疾病患者的病例资料,其中前列腺癌（PC）患者28例,前列腺增生（BPH）患者12例,每例患者均行常规MRI和DCE—MRI检查,通过与病理结果对照,在MRI图像上共选取130个样本,分为前列腺癌区、外周带非癌区和中央腺体非癌区三组,在前列腺定量参数伪彩图上取ROI并测量Ktrans、Ve及Kep值,对三组的各参数值分别行方差分析,并检验PC组Ktrans。值与Gleason评分的相关性。结果：前列腺癌区的Ktrans、ve及Kep值分别为（0．62±0．10）min-1、（0．44±0．12）和（1．45±0．25）min,外周带非癌区分别为（0．21±0．06）min-1、（0．29±0．65）和（0．76±0．21）min-1,中央区非癌区分别为（0．32±0．09）min、（0．34±0．70）和（0．95±0．26）min-1,Ktrans、Ve及Kep值在各组间差异均有统计学意义（F值分别为234．338、32．593及92．462,P值均〈0．05）;PC组Ktrans、Ve值在不同Gleason评分组间差异有统计学意义（F值分别为6．354、9．217,P值均〈0．05）,Kep值在不同Gleason评分组间差异无统计学意义（P值〉0．05）;前列腺癌区的Ktrans值与Gleason评分呈正相关（r=0．533,P〈0．05）。结论：3．0TDCE-MRI定量分析研究能为PC的诊断提供客观依据。前列腺癌区的Ktrans值与Gleason评分呈正相关,提示定量参数Ktrans值可用于评估PC的恶性程度。     

Age-related and zonal anatomical changes of apparent diffusion coefficient values in normal human prostatic tissues

PURPOSE: To identify age-related changes and differences in the diffusion of water molecules within the prostate, through diffusion-weighted imaging (DWI) of the prostate gland in healthy adult Japanese men. MATERIALS AND METHODS: A total of 114 healthy male volunteers (mean age, 55 years; range, 24-81 years) underwent DWI of the prostate with a single-shot echo-planar imaging (EPI) sequence using b-factors of 0 and 1000 seconds/mm(2). Apparent diffusion coefficient (ADC) values of six locations in the peripheral zone (PZ) and two locations in the central gland (CG) were measured and correlations between region and age were examined. RESULTS: ADC values measured within both PZ and CG regions of the prostate showed a uniform distribution, and no significant differences were found between evaluated regions. However, mean ADC values were 1.64 +/- 0.27 x 10(-3) mm(2)/second for PZ and 1.26 +/- 0.12 x 10(-3) mm(2)/second for CG, representing a significant difference. In addition, significant positive correlations were identified between ADC values for both PZ and CG regions and subject age (r = 0.526, P < 0.0001; r = 0.190, P = 0.0431, respectively). CONCLUSION: ADC values within both PZ and CG regions of the prostate increase with age, and this must be taken into consideration when using DWI in the diagnosis of prostate cancer.     

Assessment of diffusion-weighted MR imaging in liver fibrosis

PURPOSE: To assess whether hepatic fibrosis is associated with a restriction in the diffusion of water that can be analyzed with diffusion-weighted MR imaging (DWI) of the liver. MATERIALS AND METHODS: DWI was performed in 10 normal rats and 15 rats with liver fibrosis. Echo-planar DWI was performed in the living rats at 1.5 T and repeated immediately after the animals were killed. Afterwards the livers were explanted, fixed in Bouin solution, and imaged with a DW spin-echo sequence at 4.7 T. Fibrosis was quantified by densitometry on Sirius red-stained histological sections. RESULTS: In living rats the apparent diffusion coefficient (ADC) decreased with the severity of liver fibrosis (controls: 1535 +/- 294 mm(2)/second; CCl(4) (5 weeks) 1129 +/- 273 mm(2)/second; CCl(4) (9 weeks): 943 +/- 132 mm(2)/second; P = 0.002). An inverse correlation between ADC and liver fibrosis volume density was observed (r = -0.712, P < 0.001). In contrast, these findings were not observed in the rats after they were killed or in the fixated livers. CONCLUSION: Decreased ADC correlated with increased liver fibrosis in living rats, but not after death. These results suggest that restricted water diffusion cannot be assessed by DWI in liver fibrosis. Other factors, such as a decrease of perfusion, may explain the decrease of the hepatic ADC measured in vivo in rats with liver fibrosis.     

MR扩散加权成像的肝泡状棘球蚴边缘带影像特征与组织病理学对照分析

目的 探讨DWI及ADC值在评价肝泡状棘球蚴病(HAE)病变性质中的价值.方法 26例HAE患者行肝脏常规MRI和DWI,b值分别为500、800 s/mm2,获得病灶中心实性区(ADC中心)、边缘带(ADC边缘)、外周区(ADC外周)ADC值,采用单因素方差分析比较各区域ADC值.观察病灶标本的特点,取病灶边缘区域行HE染色和免疫组织化学测定微血管密度(MVD),并采用Pearson法分析边缘带ADC值与MVD的相关性.结果 选取26例HAE患者中独立病灶32个进行ADC值测量,b值分别为500、800 s/mm2时,ADC中心、ADC边缘和ADC外周值分别为(1.3±0.3)×10-3、(1.1±0.4) ×10-3、( 1.8 ±0.5)×10 -3mm2/s,( 1.2±0.4)×10-3、(1.1±0.3) ×10-3、(1.9±0.4)×10-3mm2/s,不同b值下各区域ADC值差异均有统计学意义(P值均＜0.01),两两比较结果差异亦有统计学意义(P值均＜0.05).26例32个病灶边缘区域MVD值为(12.9±3.7)个/视野,与不同b值下ADC值均无相关性(r值分别为-0.042和-0.077,P值均＞0.05).结论 DWI可以反映HAE病灶不同区域特征,而病灶边缘区域的ADC值与该区域MVD无相关性.