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。     

扩散敏感因子800时乳腺良恶性病变ADC界值的确定

目的：确定扩散敏感因子为800s/mm^2时乳腺良恶性病变的ADC界值,评价MR扩散加权成像（DWI）对乳腺良恶性病变鉴别诊断的价值。方法：回顾性分析经手术病理证实的70例（78个病灶）乳腺病变的DWI图像,其中良性病变26例（31个病灶）,恶性病变44例（47个病灶）。测量DWI图像上显示的病变表观扩散系数（ADC）值。通过ROC曲线确定ADC值的诊断阈值,并以此值进行鉴别诊断,同时计算ROC曲线下面积。结果：良恶性病变的ADC值均符合正态性分布,良恶性病变的ADC平均值分别为（1.46±0.26）×10^-3mm^2/s和（1.02±0.19）×10^-3mm^2/s,恶性病变的ADC值明显低于良性病变（P〈0.05）。约登指数最大法确定的ADC诊断阈值为1.28×10^-3mm^2/s,以此值进行鉴别诊断时的敏感度、特异度和诊断符合率分别为93.6%,75.9%,86.8%;阳性似然比最大法确定的ADC诊断阈值为1.035×103mm^2/s,以此值进行鉴别诊断时的敏感度、特异度和诊断符合率分别为46.8%,96.6%,65.8%;ROC曲线下面积为0.905（95%可信区间为0.836-0.975）。结论：扩散敏感因子为800s/mm^2时乳腺良恶性病变的ADC界值确定为1.28×10^-3mm^2/s,DWI的ADC值测定有助于乳腺良恶性病变的鉴别诊断。     

全身MR扩散加权成像在鉴别淋巴结肿大原因的应用研究

目的 探讨全身磁共振扩散加权成像(WB MR DWI)对初诊不明原因淋巴结肿大的鉴别诊断价值.方法 经病理或临床证实的初诊淋巴结病变患者78例,其中淋巴瘤31例(淋巴瘤组),肿瘤转移性淋巴结病变30例(转移性淋巴结组),炎性淋巴结17例(炎性淋巴结组),所有患者均于治疗前行WB MR DWI检查,分别记录淋巴结病变个数并测量其表观扩散系数(ADC)值,应用独立样本t检验及受试者工作特征(ROC)曲线分析每两组病变的ADC值鉴别价值.结果淋巴瘤组、转移性淋巴结组及炎性淋巴结组平均ADC值分别为(1.197 ±0.388)×10-3mm2/s、(1.343±0.299)×10-3mm2/s和(1.677 ±0.466)×10-3mm2/s,淋巴瘤与转移性淋巴结组的平均ADC值均明显小于炎性组,淋巴瘤组的平均ADC值也小于转移性淋巴结组(P＜0.01),应用ROC曲线得出鉴别淋巴瘤与转移性淋巴结、淋巴瘤与炎性淋巴结、转移性淋巴结与炎性淋巴结及良、恶性淋巴结的ADC值鉴别诊断阈值分别为1.085×10-3mm2/s、1.575×10-3mm2/s、1.655×10-3mm2/s和1.575×10-3mm2/s,敏感性和特异性分别为41.5％、80.9％,78.6％、64.5％,84.5％、57.1％和78.2％、64.5％.结论 WB MR DWI结合ADC值对初诊不明原因淋巴结肿大原因有一定鉴别诊断价值,但对淋巴瘤与转移性淋巴结的鉴别价值有限.     

颈部淋巴结的MR扩散加权成像

目的评价颈部淋巴结MR扩散加权成像（DWI）的可行性，及其在鉴别正常淋巴结和转移性淋巴结中的价值。资料与方法对34例鼻咽癌患者和14名健康志愿者进行颈部常规MR和DWI，比较两种成像技术对淋巴结的显示能力，并比较正常和转移性淋巴结ADC值差异的统计学意义。扫描采用基于敏感性编码（SENSE）技术的短恢复时间反转恢复（STIR）-平面回波成像序列（EPI）-DWI。结果DWI较常规MR能更敏感地显示淋巴结。正常淋巴结的ADC值为（0．975±0．179）×10^-3mm^2／s，转移性淋巴结的ADC值为（0．744±0．125）×10^-3mm^2／s，两者间的差异有统计学意义（P〈0．01），转移性淋巴结的ADC值明显低于正常淋巴结的ADC值。结论STIR-EPI-DWI能准确和敏感地显示颈部淋巴结，可作为淋巴结MR成像的一种新手段，并为正常淋巴结和转移性淋巴结的鉴别提供新的方法。     

MR扩散加权成像对乳腺良恶性疾病的应用研究

目的探讨MR扩散加权成像（DWI）的技术方法及表观扩散系数（ADC）值对乳腺良、恶性疾病的诊断及鉴别诊断价值。资料与方法经病理证实的乳腺病变50例,58个病灶,其中恶性32个,良性26个。检查使用Siemens1.5T磁共振仪、专用双穴乳腺表面线圈。所有病例采用单次激发自旋回波-回波平面成像（SE-EPI）序列行DWI,扩散敏感系数（b值）取0、400、600、800、1000s/mm^2。以恶性病变ADC值95%可信区间的上界作为诊断病变良、恶性的界值,所得结果与病理结果比较。结果DWI显示92.3%（24/26）的良性病变和96.9%（31/32）的恶性病变,敏感性为94.8%（55/58）。各b值良性组、恶性组和正常组之间的ADC值差异均有统计学意义（P〈0.05）。取b=1000s/mm^2,以恶性病变ADC值95%可信区间的上界1.4276×10^-3mm/s为界诊断良、恶性的敏感性为90.6%,特异性为84.6%,准确性为87.9%。结论（1）DWI对乳腺疾病的敏感性非常高。（2）ADC值是诊断和鉴别诊断乳腺良、恶性疾病的有价值的参数。（3）b=1000s/mm^2时对乳腺疾病的诊断最有价值。     

DWI对颈部淋巴结病变良恶性的鉴别诊断价值

目的:探讨DWI及其定量参数ADC值对颈部淋巴结病变良恶性的鉴别诊断价值。方法:回顾性分析经病理证实的颈部淋巴结病变患者49例共116个病灶,分为恶性组28例(60个病灶)和良性组21例(56个病灶)。患者均行常规MRI及DWI检查,测量并比较2组的ADC值,以病理结果为金标准,绘制ROC曲线,观察ADC值的诊断效能。结果:恶性组淋巴结平均ADC值为(0.73±0.17)×10~(-3)mm~2/s,低于良性组的(1.02±0.23)×10~(-3)mm~2/s(P0.05)。经ROC曲线分析,ADC阈值为0.82×10~(-3)mm~2/s时,区分颈部淋巴结良恶性病变的诊断灵敏度、特异度和曲线下面积分别为78.6%、73.3%和0.843。结论:ADC值对颈部良恶性淋巴结病变具有鉴别诊断价值。     

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.     

Application of Diffusion Weighted Imaging in Differential Diagnosis of Benign and Malignant of Stomach Neoplasm

目的 探讨扩散加权成像(diffusion-weighted imaging,DWI)及其表观扩散系数(apparent diffusion coefcient,ADC)在胃良、恶性肿瘤鉴别中的价值,确定ADC值在良恶性肿瘤鉴别中的最佳临界点.方法 39例经手术或胃镜活检病理证实的胃肿瘤性病变患者,进行常规MRI及DWI,b值采用800 s/mm2,以病理结果为金标准,统计分析胃良性和恶性占位之间的ADC值差异.结果 当b值为800 s/mm2,良性组ADC平均值为(2.200±0.959)× 10-3mm2/s,恶性组ADC平均值为(1.89±0.463)× 10-3mm2/s,两组间有显著差异(F=25.12,P＜0.05).受试者工作特征(ROC)曲线显示,区别良恶性胃部肿瘤的最佳临界点为1.915×10-3mm2/s,其敏感性为88.7％,特异性为91.1％,约登指数为0.798.结论 DWI在胃肿瘤诊断中具有可行性.b值为800 s/mm2时,胃良性和恶性肿瘤之间的ADC值存在显著统计学差异,区别胃部良恶性肿瘤的最佳临界点为1.915×10-3mm2/s,ADC值对于鉴别胃良恶性肿瘤有辅助诊断价值.     

磁共振扩散加权成像在胃肠道良、恶性病变诊断中的应用价值

目的探讨MR扩散加权成像（DWI）在胃肠道良、恶性病变诊断中的价值。资料与方法对69例胃肠道病变进行常规MR平扫和DWI，扩散敏感梯度（b值）分别为0和700s／mm^2，测量病变的表观扩散系数（ADC）值，其中29例同时续行增强扫描。结果59例恶性病变的平均ADC值为（0．96±0．11）×10^-3mm^2／s，10例良性病变的平均ADC值为（1．49±0．12）×10^-3mm^2／s，两组病变之间比较差异有统计学意义（P〈0．01）。将恶性病变ADC值95％可信区间上界1．16×100mm^2／s定位为良、恶性病变鉴别的界值，诊断敏感性为86．6％，特异性为95．8％。结论DWI有助于对胃肠道良、恶性病变的诊断和鉴别。     

DWI联合CT对肺内良恶性病变的鉴别诊断价值

【摘要】目的：探讨DWI联合CT对肺内良、恶性病变的鉴别诊断价值。方法：搜集经病理或治疗后随诊证实的肺内病变共68例,其中恶性病变46例,良性病变22例,所有患者均在接受治疗及病理检查前行CT平扫+增强扫描及DWI检查,记录b值为800s/mm2时病变的平均表观扩散系数值（ADC值）,分析良、恶性病变的ADC值差异,计算ROC曲线下面积,判断ADC值的最佳阈值及鉴别诊断效能,对比分析单独使用CT与CT联合DWI的诊断效能。结果：肺内良性病变的平均ADC值为（1.712±0.293）×10-3mm2/s,恶性病变的平均ADC值为（1.219±0.138）×10-3mm2/s,良、恶性病变的平均ADC值差异有统计学意义（P＜0.05）。ADC值的最佳诊断阈值为1.522×10-3mm2/s时,ROC曲线的曲线下面积最大（0.942）,对肺内良、恶性病变鉴别诊断的敏感度为72.7%,特异度为100%,诊断符合率为91.2%;CT对肺内良恶性病变的诊断符合率为88.2%,CT与DWI联合的诊断符合率为95.6%。结论：DWI联合CT可提高对肺内良、恶性病变的鉴别诊断符合率。     

Value of diffusion-weighted MR imaging in the differentiation between benign and malignant cervical lymph nodes

Purpose

To evaluate echo-planar diffusion-weighted MR imaging (DWI) in the differentiation between benign and malignant cervical lymph nodes.

Materials and methods

35 consecutive patients with 55 enlarged (>10 mm) cervical lymph nodes underwent MR imaging at 1.5-T. DWI was performed using a single-shot echo-planar (SSEPI) MR imaging sequence with b values (b: diffusion factor) of 0, 500 and 1000 s/mm². Apparent diffusion coefficient (ADC) maps were reconstructed for all patients and ADC values were calculated for each lymph node. Imaging results were correlated with histopathologic findings after neck dissection or surgical biopsy, findings in PET/CT or imaging follow-up. Mann-Whitney test was used for statistical analysis and a receiver operating characteristic (ROC) curve analysis was performed.

Results

Cervical lymph node enlargement was secondary to metastases from squamous cell carcinomas [n = 25], non-Hodgkin’s lymphoma [n = 6], reactive lymphadenitis [n = 20], cat scratch lymphadenitis [n = 2] and sarcoidosis [n = 2]. The mean ADC values (×10⁻³ mm²/s) were 0.78 ± 0.09 for metastatic lymph nodes, 0.64 ± 0.09 for lymphomatous nodes and 1.24 ± 0.16 for benign cervical lymph nodes. ADC values of malignant lymph nodes were significantly lower than ADC values of benign lymph nodes. 94.3% of lesions were correctly classified as benign or malignant using a threshold ADC value of 1.02 × 10⁻³ mm²/s.

Conclusion

According to our first experience, DWI using a SSEPI sequence allows reliable differentiation between benign and malignant cervical lymph nodes.     

背景抑制扩散加权成像诊断头颈部鳞癌颈部淋巴结转移的价值

目的 前瞻性地探讨背景抑制扩散加权成像(DWIBS)评价头颈部鳞癌颈部淋巴结转移的临床应用价值.方法 对20例经颈部淋巴结活检或手术病理证实的头颈部鳞癌患者(舌癌5例、鼻咽癌5例、喉癌3例、口底癌3例、口咽癌1例、喉咽癌1例、面颊癌1例和唇癌1例)进行颈部常规MR和DWIBS扫描,测量淋巴结的ADC值,选定鉴别转移性和良性淋巴结的最佳ADC阈值,并比较DWIBS与常规MRI显示和诊断转移性淋巴结的能力.两组均数间的比较采用独立样本t检验.结果 常规MR检查计数淋巴结共101枚,诊断转移性淋巴结58枚;常规MRI诊断淋巴结转移的敏感度为78%(47/60)、特异度为81%(44/54)、准确度为80%(91/114)、阳性预测值为82%(47/57)、阴性预测值为77%(44/57).DWIBS计数淋巴结共114枚,转移性淋巴结(60枚)的平均ADC值为(0.945±0.122)×10-3mm2/s,低于良性淋巴结(54枚)的平均ADC值(1.210±0.151)×10-3 mm2/s(t=-10.354,P＜0.01).以1.090×10-3 mm2/s作为ADC阈值,诊断颈部淋巴结转移的敏感度、特异度、准确度、阳性和阴性预测值分别为88%(53/60)、80%(43/54)、84%(96/114)、83%(53/64)和86%(43/50).结论 DWIBS有助于诊断头颈部鳞癌的颈部淋巴结转移,较常规MRI可提高其检出率.     

颈髓MR扩散加权成像优化b值初步研究

目的：探讨1.5T磁共振颈髓扩散加权成像（DWI）b值的选择及获取正常脊髓表观扩散系数（ADC值）。方法：50例健康志愿者进行颈髄DWI检查,采用单次激发平面回波（SSH-EPI-DWI）序列,扩散梯度因子b值分别取300、500和1000 s/mm^2,分3组进行扫描,测量正常人颈髓ADC值并分析各组DWI图像及ADC图像质量,对比不同b值对成像效果的影响。结果：50例受检者均获得较满意的DWI和ADC图像并测得正常人颈髓ADC值。随着b值由300 s/mm^2升高到1000 s/mm^2,图像信号强度逐渐降低。以b值为500 s/mm^2时成像效果较好,信噪比和对比度较高,伪影较少。在500s/mm^2时测得的50例正常颈髓的平均ADC值为（95.70±11.01）×10-5mm^2/s。结论：利用SSH-EPI-DWI序列,正常人颈髓在b值为500 s/mm^2时可获得颈髓较满意的DWI和ADC图像。     

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...     

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.     

不同b值DWI对宫颈癌放化疗疗效的评估价值

目的 探讨不同b值弥散加权成像（DWI,diffusion-weighted imaging）对宫颈癌放化疗疗效的评估价值.方法 48名接受全程放化疗治疗的宫颈癌患者分别在治疗前、治疗2周后、治疗4周后及治疗结束后进行盆腔常规MRI及DWI扫描,每次扫描均测量肿瘤的ADC值,所有ADC值均由b=0,600s/mm^2和b=0,1000s/mm^2两组ADC图得出.根据治疗结束后的结果将患者划分为完全有效组（CR）、部分有效组（PR）及无效组（SD）,并根据ROC曲线比较两组ADC图评估宫颈癌放化疗疗效的价值.结果 治疗2周及4周后CR组的ADC值提高百分比在两组ADC图中均高于RP及SD组;治疗结束后,CR组的ADC值在两组ADC图中均高于RP及SD组;其中治疗4周后及治疗结束后高b值组（b=0,1000s/mm^2）区分CR组与PR/SD组的能力高于低b值组（b=0,600s/mm^2） （P＜0.05）;低b值组所测数据的标准差均大于高b值组.结论 高b值DWI评估宫颈癌放化疗疗效的整体价值高于低b值DWI,且数值更为稳定.     

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.     

Is Diffusion-Weighted MRI Useful for Differentiation of Small Non-Necrotic Cervical Lymph Nodes in Patients with Head and Neck Malignancies?

Objective

To evaluate the usefulness of measuring the apparent diffusion coefficient (ADC) in diffusion-weighted magnetic resonance imaging to distinguish benign from small, non-necrotic metastatic cervical lymph nodes in patients with head and neck cancers.

Materials and Methods

Twenty-six consecutive patients with head and neck cancer underwent diffusion-weighted imaging (b value, 0 and 800 s/mm²) preoperatively between January 2009 and December 2010. Two readers independently measured the ADC values of each cervical lymph node with a minimum-axial diameter of ≥ 5 mm but < 11 mm using manually drawn regions of interest. Necrotic lymph nodes were excluded. Mean ADC values were compared between benign and metastatic lymph nodes after correlating the pathology.

Results

A total of 116 lymph nodes (91 benign and 25 metastatic) from 25 patients were included. Metastatic lymph nodes (mean ± standard deviation [SD], 7.4 ± 1.6 mm) were larger than benign lymph nodes (mean ± SD, 6.6 ± 1.4 mm) (p = 0.018). Mean ADC values for reader 1 were 1.17 ± 0.31 × 10^-3 mm²/s for benign and 1.25 ± 0.76 × 10^-3 mm²/s for metastatic lymph nodes. Mean ADC values for reader 2 were 1.21 ± 0.46 × 10^-3 mm²/s for benign and 1.14 ± 0.34 × 10^-3 mm²/s for metastatic lymph nodes. Mean ADC values between benign and metastatic lymph nodes were not significantly different (p = 0.594 for reader 1, 0.463 for reader 2).

Conclusion

Measuring mean ADC does not allow differentiating benign from metastatic cervical lymph nodes in patients with head and neck cancer and non-necrotic, small lymph nodes.     

相对ADC值鉴别良恶性淋巴结的实验研究

目的评价表观扩散系数(ADC)值与相对ADC(rADC)值在良恶性淋巴结鉴别中的价值。材料与方法对20只新西兰兔VX2转移淋巴结模型及20只炎性淋巴结实验兔进行常规MRI及扩散加权成像(DWI)(b值0～1000s/mm2)。在常规图像基础上测量转移淋巴结、炎性淋巴结及被测淋巴结对侧股四头肌的平均ADC值,并计算转移淋巴结/肌肉及炎性淋巴结/肌肉的rADC值。所有ADC和rADC结果以x-±s表示,并进行统计学分析。利用受试者工作特征(ROC)曲线计算两者诊断的敏感性及特异性。结果良恶性淋巴结的ADC值与rADC值之间差异均存在统计学意义(P=0.021,t=-3.298;P<0.0001,t=-4.761)。良恶性淋巴结ADC值曲线下面积为0.791,诊断阈值为0.889×10-3mm2/s,敏感性为80%,特异性为75%;rADC值曲线下面积为0.855,诊断阈值为0.671,敏感性为80%,特异性为85%。结论 rADC较ADC值能更准确地鉴别良恶性淋巴结。