DWIBS 对直肠癌淋巴结转移的初步研究

目的：探讨背景信号抑制扩散加权成像(DWIBS)在直肠癌淋巴结转移诊断中的应用价值。方法30例经肠镜确诊的直肠癌患者行常规 MRI 及 DWIBS 检查。对照术后病理结果,确定转移性和非转移性淋巴结。测量淋巴结实质部分的表观扩散系数(ADC)值,比较差异有无统计学意义,采用受试者工作特征曲线(ROC)分析确定 ADC 值的诊断阈值。结果73枚淋巴结中,转移性淋巴结52枚,非转移性淋巴结21枚。转移性与非转移性淋巴结实质部分的 ADC 值分别为(0.881±0.094)×10-3 mm2/s和(1.072±0.108)×10-3 mm2/s,差异有统计学意义(P <0.05)。当以 ADC=0.957×10-3 mm2/s 作为鉴别转移性与非转移性淋巴结的诊断指标,其诊断价值为优(Az 值=0.919,P <0.05),灵敏度为90.5%,特异度为80.8%。结论ADC 值可用于直肠癌淋巴结转移的鉴别,DWIBS 在直肠癌淋巴结转移的评估中具有较高的应用价值。     

颈部病变淋巴结实质区和坏死区表观扩散系数值的鉴别诊断价值

目的 探讨淋巴结实质区和坏死区的表观扩散系数(ADC)值对颈部淋巴结病变的鉴别诊断价值.方法 对36例颈部淋巴结转移癌、19例淋巴瘤和23例淋巴结结核患者进行扩散加权成像(DWI),测量并比较不同病变巾淋巴结实质区和坏死区的ADC值,评价两者对3种淋巴结病变的鉴别诊断能力.共对病理(114枚)和临床随访(63枚)证实的177枚淋巴结进行ADC值的测量和分析,其中转移癌性淋巴结84枚,淋巴瘤性淋巴结40枚,结核性淋巴结53枚.2组均数的比较采用独立样本t检验,2组以卜均数的比较采用单向方差分析(one-way ANOVA).结果 转移癌、淋巴瘤和结核的淋巴结实质区的ADC值分别为(0.93±0.16)、(0.64±0.13)和(1.01±0.11)×10-3mm2/s(F=82.928,P<0.01),淋巴结转移癌和结核中淋巴结坏死区的ADC值分别为(2.02±0.36)、(1.25±0.15)×10-3mm2/s(t=12.045,P<0.01).当淋巴结实质区的ADC值≤0.77×10-3mm2/s时,诊断为淋巴瘤的敏感度、特异度分别为83%和89%.当淋巴结坏死区的ADC值≥1.60×10-3mm2/s时,诊断为淋巴结转移癌的敏感度、特异度分别为88%、100%.结论 测量淋巴结的ADC值,尤其是坏死区的ADC值有助于淋巴结病变的鉴别诊断.     

颈部良恶性淋巴结的磁共振扩散加权成像研究

目的 评价磁共振平面回波扩散加权成像在鉴别颈部良、恶性淋巴结肿大的诊断价值,探讨表观弥散系数(ADC)值与转移性淋巴结分级之间的关系.方法 34例颈部淋巴结增大病人的52个淋巴结(>10 mm),经颈部淋巴结清扫(25个)或穿刺活检(14个)及影像学随访(13个)证实.SSEPI-DWI序列(b=0 mm2/s和1 000 mm2/s),重建出ADC图并测量ADC值.统计学分析包括方差分析及Sidak t或Tamhane's T2检验、受试者操作特征(ROC)曲线分析.P<0.05认为具有统计学意义.结果 喉鳞癌性转移淋巴结(25个)、淋巴瘤性淋巴结(11个)、良性淋巴 结(16个)的平均ADC值分别为(0.78±0.09)×10-3mm2/s、( 0.64±0.09)× 10-3mm2/s、(1.22±0.16)×10-3mm2/s.转移淋巴结组,高分化组ADC值高于低分化组(P<0.05).低分化组转移性淋巴结与淋巴瘤性淋巴结ADC值无显著差异(P>0.05).恶性淋巴结的ADC值明显低于良性淋巴结(P<0.05),鉴别良恶性淋巴结ADC值的最佳临界点值为0.94×10-3mm2/s.结论 在原发性喉鳞癌转移性淋巴结中,其ADC值与淋巴结分级有关.应用SSEPI-DWI可以可靠地鉴别喉鳞癌颈部转移性淋巴结和良性淋巴结,但是无法区分低分化型喉鳞癌转移性淋巴结与淋巴瘤性淋巴结.     

扩散加权成像对肺癌术前纵隔淋巴结的评价研究

目的:利用磁共振扩散加权成像(DWI)评估肺癌术前纵隔淋巴结的转移情况,探讨其在鉴别转移性和非转移性纵隔淋巴结中的临床价值.方法:对30例肺癌患者行肺部MRI常规和DWI检查.DWI采用单次激发自旋回波-平面回波(SSEPI)和短反转时间恢复序列(STIR)序列.将DWI图像中纵隔淋巴结和术中切除淋巴结进行严格匹配,利用感兴趣区法分别测量原发灶和各纵隔淋巴结的表观扩散系数(ADC)值为ADC原发灶和ADC淋巴结,并计算得到ADC原发灶和ADC淋巴结的差值绝对值D-value,比较转移组淋巴结和非转移组淋巴结的ADC值和D-value值有无统计学差异.结果:转移组淋巴结的ADC值为(2.04±0.53)×10-3 mm2/s,非转移组淋巴结ADC值为(2.98±0.48)×101 mm2/s,转移组淋巴结ADC值明显低于非转移组淋巴结(P＜0.001).转移组淋巴结的D-value值为(0.76±0.45)×10-3 mm2/s,非转移组淋巴结的D-value值为(1.58±0.46)×10-3mm2/s,转移组淋巴结的D-value值明显低于非转移组淋巴结(P＜0.001).ADC值取0.0025×10-3mm2/s为临界值鉴别转移和非转移性淋巴结的敏感度、特异度、阳性预测值、阴性预测值分别为87.3％、84.6％、82.7％、88.7％;D-value值取0.001×10-3mm2/s为临界值鉴别转移和非转移性淋巴结的敏感度、特异度、阳性预测值、阴性预测值分别为76.4％、87.7％、84.0％、81.4％.结论:DWI通过测量、计算纵隔淋巴结的ADC值和D-value值,可用于肺癌患者术前评估淋巴结转移情况.     

DWI在盆腔淋巴结转移瘤诊断中的临床应用

目的 :探讨DWI在盆腔淋巴结转移瘤诊断中的应用价值。方法 :回顾性分析27例术前经MRI检查的盆腔淋巴结肿大患者,其中12例直肠癌,5例卵巢癌,7例宫颈癌,3例子宫内膜癌,并与术后病理对照,明确转移性和非转移性淋巴结,比较2组淋巴结的ADC值差异。结果:27例共标记肿大淋巴结112枚,其中转移性74枚,非转移性38枚。转移性淋巴结平均ADC值为(0.846±0.210)×10~(-3)mm~2/s,非转移性淋巴结平均ADC值为(1.157±0.130)×10~(-3) mm~2/s,2组比较差异有统计学意义(P0.01)。当以ADC值=0.93×10~(-3)mm~2/s作为区分转移与非转移性淋巴结的标准时,诊断价值为优(曲线下面积为0.920,P0.01),敏感度为89.6%,特异度为81.0%。结论:DWI在盆腔淋巴结转移瘤的诊断中具有良好的应用价值,可通过测量肿大淋巴结的ADC值鉴别其良恶性。     

背景抑制磁共振扩散成像技术在肝占位及转移淋巴结成像的应用研究

目的 探讨背景抑制扩散成像(diffusion weighted imaging with background suppression,DWIBS)技术在肝脏占位及转移淋巴结成像的应用研究. 资料与方法 对26例肝脏占位患者行常规MRI及DWIBS检查,分别测量肿瘤实质、瘤内坏死区域、转移淋巴结及正常肝实质的表观扩散系数值(ADC值).行3D 最大密度投影(MIP)重组及黑白翻转技术观察瘤体与淋巴结的信号特点. 结果 肿瘤实质、瘤内坏死区域、转移淋巴结及正常肝实质的平均ADC值分别为(0.873±0.38)× 10-3 mm2/s、(2.12±0.48) × 10-3 mm2/s、(0.856±0.41)× 10-3 mm2/s、(1.296±0.67) ×10-3 mm2/s;肿瘤实质与瘤内坏死灶间ADC值有统计学差异(P＜0.05),肿瘤实质与正常肝实质间ADC值有统计学差异(P＜0.05),肿瘤实质与肿大淋巴结间ADC值的差异无统计学意义(P＞0.05).DWIBS瘤灶显示率96.1%,淋巴结显示率94.7%.瘤灶与肿大淋巴结呈高信号,反转图呈低信号. 结论 背景抑制扩散成像可以通过ADC值对肝脏占位及转移淋巴结量化,并能直观地、立体地、多角度观察淋巴结的分布.     

最小ADC值鉴别诊断颈部转移性淋巴结与淋巴瘤的价值

目的探讨最小表观扩散系数值在鉴别诊断颈部转移性淋巴结与淋巴瘤的价值。方法回顾性分析经病理组织学证实的10例(26个病灶)颈部淋巴瘤和18例(34个病灶)转移性淋巴结患者MRI图像,测量并比较颈部转移性淋巴结与淋巴瘤的最小ADC值。结果颈部淋巴瘤最小ADC值低于转移性淋巴结最小ADC值,分别为(0.58±0.12)×10-3mm~2/s、(0.76±0.16)×10-3mm~2/s,两者间差异有统计学意义(P0.05)。结论最小ADC值有助于鉴别诊断颈部转移性淋巴结与淋巴瘤。     

MR扩散加权成像对结直肠癌区域淋巴结转移的诊断价值

目的探讨MR扩散加权成像(DWI)诊断结直肠癌区域淋巴结转移的价值。方法 75例结直肠癌病人在接受常规MR及DWI检查后均接受肿瘤切除术,对照术后病理结果,确定区域转移性和非转移性淋巴结,测量淋巴结及原发肿瘤的ADC值,比较受试者操作特征(ROC)曲线下面积(AUC),评估淋巴结的ADC值及rADC值(淋巴结/原发肿瘤)对鉴别诊断转移性与非转移性淋巴结的价值。结果转移性淋巴结60个,非转移性淋巴结126个。转移性淋巴结与非转移性淋巴结的ADC值分别为(0.79±0.12)×10-3mm2/s和(0.98±0.23)×10-3mm2/s(P<0.01);转移性淋巴结的rADC值低于非转移性淋巴结(0.91±0.14︰1.21±0.28),差异有统计学意义(P<0.01)。两组淋巴结ADC值的ROC曲线的AUC为0.776,阈值1.11×10-3mm2/s,敏感度为61.9%,特异度为88.0%;rADC值的AUC为0.883,阈值为1.03,敏感度为78.6%,特异度为90%。结论 DWI对诊断结直肠癌区域淋巴结转移有一定价值,用rADC值诊断淋巴结转移的准确性高于ADC值。     

肺部疾病MR背景抑制扩散成像应用初探

目的 初步评价MR背景抑制扩散成像(DWIBS)最大密度投影(MIP)图像及表观扩散系数(ADC)值的定量测量在肺部疾病中的应用价值.方法 61例患者接受了肺部DWIBS,其中肺癌38例,肺部炎性病变23例,分析肺部疾病三维(3D)MIP重组图像表现,确定肺部病变的ADC值范围,评价DWIBS对肺部疾病的诊断价值.结果 DWIBS上肺癌及炎性病变表现为不同形态的信号强度密集区域.DWIBS上中央型肺癌平均ADC值为(1.05±0.23)×10-3 mm2/s,周围型肺癌平均ADC值为(1.10±0.17)×10-3 mm2/s,各种炎性病变平均ADC值为(1.69±0.29)×10-3 mm2/s,周围型肺癌与炎性病变的平均ADC值差异有统计学意义(P＜0.05).3.0 T MRI+DWIBS对肺部疾病诊断的敏感性、特异性及准确性(分别为86.84%、82.60%和85.24%)高于单纯MRI诊断(分别为78.94%、78.26%和78.68%).结论 DWIBS能够立体、直观地显示病灶,实现了肺部病变ADC值的定量测量,有望成为肺部疾病鉴别诊断的方法之一.     

3.0T MR多b值DWI对鼻咽癌患者颈部良恶性淋巴结的鉴别诊断价值

目的探讨3.0T磁共振多b值扩散加权成像(DWI)对鼻咽癌患者颈部良恶性淋巴结的鉴别和诊断价值。方法收集本院66例鼻咽癌患者的临床资料,并以35例良性淋巴结肿大患者为对照。所有患者均行MR常规平扫、增强和多b值DWI影像学检查,比较不同b值下鼻咽癌患者原发灶、颈部转移性小淋巴结、转移性大淋巴结与良性淋巴结肿大患者表观扩散系数(ADC)值的差异。通过绘制受试者工作特征(ROC)曲线计算诊断阈值、ROC曲线下面积、敏感度和特异度,评价不同b值下ADC值对鼻咽癌颈部良恶性淋巴结的鉴别和诊断价值。结果随着b值的增加,鼻咽癌患者原发灶、颈部转移性小淋巴结、转移性大淋巴结与良性淋巴结肿大患者ADC值呈现减少的趋势;鼻咽癌患者原发灶、颈部转移性小淋巴结、转移性大淋巴结之间ADC值的比较,差异均无统计学意义(P>0.05);鼻咽癌患者原发灶、颈部转移性小淋巴结、转移性大淋巴结ADC值均显著低于良性淋巴结肿大患者(P<0.05)。在b值分别取400、600、800、1000s/mm^2时,其对应的ROC曲线下面积分别为0.77、0.82、0.91、0.87。当b=800s/mm^2时,其鉴别和诊断淋巴结良恶性的价值最高,此时ADC值诊断鼻咽癌颈部转移性小淋巴结的阈值为0.945×10^-3mm^2/s,诊断敏感度为98.49%,特异度为79.63%,约登指数为0.78。结论3.0T MR多b值DWI检查可有效区分良恶性淋巴结的性质,并且在b值为800s/mm^2时,其鉴别和诊断不同淋巴结性质的能力最强,可用于临床鉴别和诊断鼻咽癌患者颈部淋巴结转移瘤。     

MR背景抑制扩散加权成像在乳腺癌的应用

目的 探讨MR扩散加权成像(DWI)结合短时间反转恢复回波成像(STIR-EPI)背景抑制(BS)技术在乳腺癌成像的技术参数及其可行性.方法 回顾性分析26例乳腺癌的MR DWIBS测得各组织的表观扩散系数(ADC),利用三维最大强度投影(3D-MIP)重组及黑白反转技术,观察病变显示效果.观察乳腺痛DWI及DWIBS两种方法的显示率.对乳腺各组织的ADC值进行随机区组设计的方差分析,在乳腺癌与良性病变ADC值的比较中,采用t检验.对两种成像方法乳腺癌的显示率进行配对资料X2检验.结果 在扩散敏感因子(b)=800 mm2/s的图像中,乳腺癌多表现为高信号,其ADC值分别为:肿瘤实质(0.93±0.25)×10-3 mm2/s、瘤内坏死灶(2.06±0.17)×10-3 mm2/s、正常腺体(1.92±0.23)×10-3 mm2/s、转移性淋巴结(1.10 ± 0.14)×10-3mm2/s,各种组织间两两比较,差异具有统计学意义(P值均＜0.01).DWIBS经MIP重组及黑白反转技术,病变周围组织信号被抑制,得到类正电子发射体层成像(PET)图像.在乳腺癌中,DWIBS对肿瘤实质(92.3/)及转移性淋巴结(88.4/)的显示率要高于DWI序列(分别为57.6/和42.3/),差异有统计学意义(x2值分别为8.307、12.235,P均＜0.05).乳腺癌与良性病变ADC值分别为(1.092±0·17)×10-3和(2.154±0.53)×10-3mm2/s,差异有统计学意义(t=8.626,P＜0.05).结论 MRDWIBS在显示病灶方面有一定优势,应用DWI结合ADC值对乳腺癌的诊断具有临床应用前景.     

Detection of lymph node metastasis in cervical and uterine cancers by diffusion-weighted magnetic resonance imaging at 3T

PURPOSE: To evaluate diffusion-weighted imaging (DWI) for detection of pelvic lymph node metastasis in patients with cervical and uterine cancers. MATERIALS AND METHODS: Fifty patients scheduled for pelvic lymph node dissection were enrolled for 3T magnetic resonance imaging (MRI) using a single-shot echo-planar DWI technique, body-phased array coil, b = 0, 1000 s/mm(2). We measured short/long-axis diameters, mean apparent diffusion coefficient (ADC) values of all identifiable nodes, relative ADC values between tumors and nodes, and utilized their cutoff values to validate the diagnostic accuracy internally. Histopathologic results served as the reference standard. RESULTS: The relative ADC values between tumor and nodes were significantly lower in metastatic than in benign nodes (0.06 vs. 0.21 x 10(-3) mm(2)/s, P < 0.001; cutoff value 0.10 x 10(-3) mm(2)/s). Compared to conventional MRI, the method combining size and relative ADC values resulted in better sensitivity (25% vs. 83%) and similar specificity (98% vs. 99%). The smallest metastatic lymph node detected by this method measured 5 mm on its short axis. CONCLUSION: The combination of size and relative ADC values was useful in detecting pelvic lymph node metastasis in patients with cervical and uterine cancers.     

Discrimination of metastatic cervical lymph nodes with diffusion-weighted MR imaging in patients with head and neck cancer

BACKGROUND AND PURPOSE: Metastasis to the regional cervical lymph nodes may be associated with alterations in water diffusivity and microcirculation of the node. We tested whether diffusion-weighted MR imaging could discriminate metastatic nodes. METHODS: Diffusion-weighted echo-planar and T1- and T2-weighted MR imaging sequences were performed on histologically proved metastatic cervical lymph nodes (25 nodes), benign lymphadenopathy (25 nodes), and nodal lymphomas (five nodes). The apparent diffusion coefficient (ADC) was calculated by using two b factors (500 and 1000 s/mm(2)). RESULTS: The ADC was significantly greater in metastatic lymph nodes (0.410 +/- 0.105 x 10(-3) mm(2)/s, P <.01) than in benign lymphadenopathy (0.302 +/- 0.062 x 10(-3) mm(2)/s). Nodal lymphomas showed even lower levels of the ADC (0.223 +/- 0.056 x 10(-3) mm(2)/s). ADC criteria for metastatic nodes (>/= 0.400 x 10(-3) mm(2)/s) yielded a moderate negative predictive value (71%) and high positive predictive value (93%). Receiver operating characteristic analysis demonstrated that the criteria of abnormal signal intensity on T1- or T2-weighted images (A(z) = 0.8437 +/- 0.0230) and ADC (A(z) = 0.8440 +/- 0.0538) provided similar levels of diagnostic ability in differentiating metastatic nodes. The ADC from metastatic nodes from highly or moderately differentiated cancers (0.440 +/- 0.020 x 10(-3) mm(2)/s, P <.01) was significantly greater than that from poorly differentiated cancers (0.356 +/- 0.042 x 10(-3) mm(2)/s). CONCLUSION: Diffusion-weighted imaging is useful in discriminating metastatic nodes.     

扩散加权成像鉴别兔炎性及转移性淋巴结肿大的实验研究

目的 探讨DWI鉴别兔良、恶性淋巴结肿大的价值.方法 对18只炎性增生性兔淋巴结(34个)肿大模型和9只肿瘤转移性兔淋巴结(18个)肿大模型进行常规MR和DWI检查,并采用独立样本t检验比较2组淋巴结短径和ADC值的差异.结果 对34个炎性增生型淋巴结和18个肿瘤转移性淋巴结进行了观察,炎性组和转移组淋巴结的短径分别为(8.14±2.79)和(6.29±1.48)mm,差异无统计学意义(t=2.624,P>0.05).炎症组和转移组淋巴结的ADC值分别为(1.19±0.31)×10-3和(1.31±0.27)×10-3mm2/s,差异无统计学意义(t=1.449,P>0.05).结论 DWI可显示肿大的淋巴结,但其ADC值差异不大,不足以作为比较并鉴别淋巴结良恶性的手段.     

Feasibility of diffusion-weighted imaging in the differentiation of metastatic from nonmetastatic lymph nodes: early experience

PURPOSE: To investigate the feasibility of diffusion-weighted imaging (DWI) in the differentiation of metastatic from nonmetastatic lymph nodes. MATERIALS AND METHODS: In 125 patients who underwent lymph node dissection for uterine cervical cancer, DWI was performed at b value of 0 and 1000 s/mm2. By referring to the surgical maps of the pelvic lymph nodes, the apparent diffusion coefficient (ADC) was compared in the metastatic and nonmetastatic lymph nodes, and receiver-operating-characteristics analysis was performed to evaluate the diagnostic performance of the ADC in differentiating metastatic from nonmetastatic lymph nodes. RESULTS: The ADC were significantly lower in the metastatic lymph nodes (0.7651x10(-3) mm2/s+/-0.1137) than in the nonmetastatic lymph nodes (1.0021x10(-3) mm2/s+/-0.1859; P<0.001). The area-under-the-curve of ADC for differentiating metastatic from nonmetastatic lymph nodes, was 0.902. The sensitivity and specificity of ADC for differentiating metastatic from nonmetastatic lymph nodes, were 87% for the ADC and 80%, respectively. CONCLUSION: DWI is feasible for differentiating metastatic from nonmetastatic lymph nodes in patients with uterine cervical cancer.     

DWI评估宫颈癌盆腔淋巴结转移的应用价值

目的探讨扩散加权成像(DWI)对于鉴别宫颈癌转移与非转移淋巴结的诊断价值。资料与方法 36例宫颈癌初诊患者于治疗前行常规MRI及DWI检查,观察并比较宫颈癌转移淋巴结与非转移淋巴结常规MRI及表观扩散系数(ADC)图表现,测量各淋巴结的长径(L)、短径(S)、T2信号强度、平均ADC值和最小ADC值,利用受试者工作特征(ROC)曲线下面积(Az)评价上述各项指标鉴别宫颈癌转移与非转移淋巴结的诊断效能。结果转移淋巴结短径和长径的平均秩次均大于非转移淋巴结,且两者差异具有统计学意义(均为P=0.000),而转移淋巴结与非转移淋巴结的L/S、S/L以及T2信号强度差异均无统计学意义(P=0.261;P=0.157;P=0.166);转移淋巴结的平均ADC值和最小ADC值均低于非转移淋巴结,且差异均具有统计学意义(均为P=0.000);短径、长径、平均ADC值和最小ADC值对鉴别宫颈癌转移与非转移淋巴结均有诊断意义(Az>0.5),其中最小ADC值的诊断效能最高,选取最小ADC阈值为0.983×10-3mm2/s时,其敏感性和特异性分别为94.6%和91.8%。结论 DWI有助于宫颈癌转移和非转移淋巴结的检出,最小A...     

Comparison between malignant and benign abdominal lymph nodes on diffusion-weighted imaging

RATIONALE AND OBJECTIVES: The purpose of this study is to review the apparent diffusion coefficient (ADC) values of benign and metastatic abdominal lymph nodes on diffusion-weighted imaging (DWI). MATERIALS AND METHODS: Twenty-eight patients with a total of 40 benign (20 patients) and 16 malignant (8 patients) lymph nodes who underwent DWI MRI of the abdomen (b = 0.600) were enrolled in the study. ADC values of the lymph nodes were measured and comparison was made between benign and malignant groups. RESULTS: Mean ADC value of lymph nodes was 2.38 +/- 0.29 and 1.84 +/- 0.37 x 10(-3) mm(2)/sec in the benign and malignant groups, respectively. There was a significant statistical difference between the ADC values of benign and malignant lymph nodes (P < .0005). CONCLUSION: A wide range of ADC values exist in patients with metastatic abdominal lymph nodes, with a tendency of higher ADC values in benign lymph nodes.