ADC值定量评估甲状腺良恶性结节鉴别中的价值研究

目的 探讨磁共振扩散加权成像(diffusion weighted imaging,DWI)的表观扩散系数(ADC)值在良、恶性甲状腺结节鉴别诊断中的价值.方法 选取分析甲状腺结节患者65例.采用b值为800 s/mm2自旋回波扩散加权成像(SE EPI)序列扫描,测量病变面积ADC值,进行Mann-Whitney U...     

相对表观扩散系数在脑转移瘤疗效评估中的价值

目的：探讨磁共振扩散加权成像（DWI）相对表观扩散系数（rADC）在脑转移瘤疗效评估中的价值。方法：搜集经病理或临床确诊为脑转移瘤患者21例（共计病灶42个）,随访2～8次,行DWI及MRI增强扫描,测量肿瘤最大直径、肿瘤实质及对侧正常脑白质的ADC值,计算rADC值。分析肿瘤实质区治疗前rADC值或治疗前后rADC值差值（治疗后rADC值～治疗前rADC值）对疗效预测的可行性。结果：按治疗后肿瘤直径变化分为治疗有效组与无效组,两组肿瘤实质区治疗前rADC值差异无统计学意义（P〉0．05）。肿瘤实质区治疗前后rADC差值与下次治疗结果对照,rADC差值预测脑转移瘤治疗疗效的闽值为0．01,敏感度、特异度、准确度分别为92．86％、75．00％、83．33％。经一致性检验Kappa指数为0．6696。结论：脑转移瘤实质区rADC治疗前后差值能用于预测脑转移瘤治疗效果,rADC值增高提示治疗有效,降低提示治疗无效,对临床治疗方式的选择和个性化治疗方案的制定有一定价值。     

ADC值在术前评价脑胶质瘤病理级别的应用价值

胶质瘤是颅内最常见的原发肿瘤之一,临床在手术治疗、放射治疗、化学药物治疗等方面有明显进展,但胶质母细胞瘤的预后较差。用影像学方法评估胶质瘤恶性程度对指导临床治疗十分必要。国内外学者利用MR扩散加权成像(DWI)对表观扩散系数(ADC)与肿瘤细胞构成及病理级别的相关性进行了初步探讨,研究显示通过DWI能够反映肿瘤病变的组织学特性,对肿瘤病变术前评估具有一定价值。本研究证实,ADC值与胶质瘤的良恶性有很高的相关性,结合常规MRI检查可为临床术前治疗方案的制定提供可靠依据。1材料与方法1.1临床资料收集2005年2月~2006年12月我…     

不同年龄组幕上脑实质室管膜瘤ADC值特点分析

目的 探讨不同年龄组幕上脑实质室管膜瘤ADC值特点及ADC值在幕上脑实质室管膜瘤诊断中的应用价值.方法 搜集33例经手术和病理证实的幕上脑实质室管膜瘤患者影像资料,包括MRI平扫、扩散加权成像(DWI)及增强检查,将患者分为儿童组(＜12岁)、成人组(≥18岁),对两组不同病理类型ADC值进行统计学分析和均值比较.结果 儿童组12例,平均rADC值0.94 ±0.52,WHOⅡ型4例,WHOⅡ～Ⅲ型1例,WHOⅢ型7例;成人组21例,平均rADC值1.17±0.36,WHOⅡ型1例,WHOⅡ～Ⅲ型2例,WHOⅢ型18例;WHOⅡ型rADC值儿童组小于成人组;WHOⅡ～Ⅲ型rADC值儿童组小于成人组;WHOⅢ型儿童组rADC值小于成人组,两组间rADC值差异具有统计学意义(t=3.29,P=0.00).结论 儿童组、成人组幕上脑实质室管膜瘤影像表现不同,rADC值存在差异,儿童组各病理类型rADC值均小于成人组.ADC值在幕上脑实质室管膜瘤诊断中具有重要意义.     

MR DWI及ADC值在急性脑梗死诊断中的应用价值

目的评价磁共振扩散加权成像（DWI）和表观扩散系数（ADC）在急性脑梗死诊断中的临床价值。方法选取临床上拟诊为脑梗死患者186例进行常规MR扫描及DWI检查,根据发病时间分成超急性期（〈6h）、急性期（6～72h）、亚急性期（3～7d）3个组。测定各组梗死灶ADC值及健侧ADC值,并计算相对ADC（rADC）。结果超急性期、急性期、亚急性期梗死灶ADC值均低于健侧相应区域（配对t检验,P〈0．01）;超急性期、急性期及亚急性期病例之间rADC有统计学差异（单因素方差分析,F=7．663,P=0．001）。结论DWI在脑梗死超急性期、急性期、亚急性期均具有很高的敏感性,各期梗死灶rADC值有时间相关性,对脑梗死的准确分期有重要价值。     

ADC值和相对ADC鉴别乳腺良恶性病变的价值

目的 探讨ADC值和相对ADC(relative ADC,rADC)鉴别乳腺良恶性病变的价值.方法 回顾性分析2011年1月～2018年12月济宁医学院附属医院通过病理或活检证实的乳腺病变,其中良性病变组31例,恶性病变组41例,测量病变区ADC值及其周围正常腺体ADC值,并计算rADC(病变ADC值/周围正常腺体AD...     

ADC值及rADC值定量分析在弥漫型自身免疫性胰腺炎与急性胰腺炎鉴别诊断中的应用

目的：探讨弥漫型自身免疫性胰腺炎(AIP)与急性胰腺炎(AP)的ADC值、相对ADC(r ADC值)在AIP与AP鉴别诊断中的价值。方法：收集经临床确诊的MRI资料完整的弥漫型AIP患者14例(AIP组),纳入符合要求的AP患者30例(AP组)及胰腺正常者32例(正常胰腺组),比较3组的ADC值及r ADC值。结果：AIP组ADC值明显低于AP组和正常胰腺组,差异均有统计学意义(均P<0.05);AIP组r ADC值明显低于AP组和正常胰腺组,差异均有统计学意义(均P<0.05);ADC值鉴别诊断AIP与AP的AUC为0.793,临界值为1 008.89×10^-6mm²/s,对应的敏感度为57.0%,特异度为93.0%;r ADC值鉴别诊断AIP与AP的AUC为0.758,临界值为0.865,对应敏感度为92.9%,特异度为50.0%。结论：弥漫型AIP与AP患者胰腺的ADC值及r ADC值存在差异。当患者症状不典型时,该差异可作为两者鉴别的影像学依据。     

ADC值在髓母细胞瘤瘤周浸润及复发评估中的价值

【摘要】目的：探讨ADC值在髓母细胞瘤（MB）瘤周浸润及复发评估中的价值。方法：将具有手术病理证实、术前常规MRI平扫、增强和DWI检查,且术后至少2次MRI随访的29例MB患者,根据术后随访结果分为复发组与未复发组,将两组患者的肿瘤实质区、瘤周区最小ADC值,瘤周相对ADC值（瘤周区与对侧正常脑组织区最小ADC值的比值,即rADC）进行统计学分析,同时绘制ROC曲线,评估ADC值预测肿瘤浸润及复发的诊断效能。结果：29例MB患者中,复发组15例,未复发组 14例。复发组的瘤周区最小ADC值［（0.558±0.053）×10-3mm2/s］小于未复发组［（0.637±0.043）×10-3mm2/s］,两者差异具有统计学意义（Z=3.295,P<0.05）;复发组的rADC值（0.853±0.065）小于未复发组（0.933±0.073）,两者差异具有统计学意义（Z=2.581,P<0.05）;瘤周区最小ADC值取0.606×10-3mm2/s时,预测MB瘤周细胞浸润的诊断敏感度为78.6%,特异性为73.3%。结论：ADC值对预测MB瘤周浸润及复发有辅助诊断价值。     

DWI和ADC值测量在颅内囊性病变鉴别诊断中的价值

目的:评价DWI与ADC值对颅内囊性病变的鉴别诊断价值以及相关的生物物理学机制.方法:经手术病理证实的脑脓肿20例、囊变坏死性脑肿瘤50例、表皮样囊肿20例和蛛网膜囊肿35例,在术前均接受了常规MRI和DWI检查.结果:脑脓肿在DWI上表现为明显的高信号,ADC值为(0.67±0.178)×10-3mm2/s;脑肿瘤囊变坏死灶在DWI上表现为明显的低信号,ADC值为(2.48±0.156)×10-3mm2/s,脑脓肿ADC值明显低于脑肿瘤囊变坏死灶ADC值(P<0.01).表皮样囊肿在DWI上表现为明显的高信号,ADC值为(1.19±0.157)×10-3mm2/s;蛛网膜囊肿在DWI上表现为明显的低信号,ADC值为(3.01±0.321)×10-3mm2/s,表皮样囊肿ADC值明显低于蛛网膜囊肿ADC值(P<0.01).结论:DWI和ADC值测量可有效鉴别脑脓肿与囊变坏死性脑肿瘤;DWI和ADC值测量能有效鉴别表皮样囊肿和蛛网膜囊肿.     

最小ADC值在评估垂体大腺瘤Ki-67增殖指数中的价值

目的 探讨最小表观扩散系数(minADC)值在评估垂体大腺瘤Ki-67增殖指数中的价值.方法 回顾性分析2018年1月至2020年6月经手术病理证实的54例垂体大腺瘤患者的病理及影像资料.根据Ki-67增殖指数表达情况将所获得病例划分为低表达组(＜3％)及高表达组(≥3％),并在ADC图像中测量二者的minADC值.利...     

Microperfusion‐induced elevation of ADC is suppressed after contrast in breast carcinoma

Purpose

To investigate the effect of gadolinium (Gd)‐DTPA on the apparent diffusion coefficient (ADC) of breast carcinoma and to analyze the relationship between pre/postcontrast ADC and the degree of contrast enhancement.

Materials and Methods

Nineteen histopathologically confirmed breast carcinomas (mean size = 22 mm) were analyzed. Their ADCs before and after contrast administration were measured. The contrast‐to‐noise ratios (CNRs) of the tumors were measured on fat‐suppressed 3D T1‐weighted images in precontrast, early, and late postcontrast phases. These results were correlated with the measured ADC values.

Results

A significant decrease in the measured ADC was noted after contrast administration (?23%, P = 0.01). Lesions with relatively high ADC before contrast (>1.3 × 10^?3 mm²/sec; n = 12) demonstrated a larger degree of ADC reduction (mean 34%) than lesions with low ADC (≤1.3 × 10^?3 mm²/sec; n = 7) (mean 4.5%). When an early postcontrast image was used as a surrogate marker of malignant potential, we found a significant inverse correlation with postcontrast ADC (γ = ?0.57, P = 0.02).

Conclusion

Postcontrast ADC exhibited lower values than precontrast ADC, which is thought to reflect suppression of the microperfusion‐induced effect on diffusion‐weighted imaging. Postcontrast ADC may be a better indicator than precontrast ADC to reflect malignant potential of tumors. J. Magn. Reson. Imaging 2009;29:1080–1084. © 2009 Wiley‐Liss, Inc.

     

直肠管状腺癌磁共振扩散加权成像 ADC 值与肿瘤分化程度的关系

目的：探讨磁共振扩散加权成像(DWI)及表观扩散系数(ADC)与直肠管状腺癌病理分化程度的相关性。方法回顾性分析在本院术前行 MRI 检查且手术病理证实的38例直肠管状腺癌患者的 DWI 影像特点,其中高分化9例、中分化15例、低分化14例。在 b 值为0 s/mm2和1000 s/mm2条件下计算 ADC 值并分析其与肿瘤分化程度的相关性。结果高分化组平均 ADC值(0.92±0.05)×10-3 mm2/s;中分化组平均 ADC 值(0.79±0.10)×10-3 mm2/s;低分化组平均 ADC 值(0.71±0.06)×10-3 mm2/s。不同分化程度的直肠管状腺癌各组别 ADC 值有明显差异(P <0.05);ADC 值与肿瘤分化恶性程度呈负相关,相关系数为-0.704,P <0.01。结论DWI 及 ADC 值的测量可成为一种判断直肠管状腺癌分化恶性程度的重要检查手段。     

ADC 值和 DCE-MRI 定量参数值与直肠癌临床病理的相关性研究

目的：探讨3.0T MR 表观扩散系数(ADC)值和动态对比增强定量参数容量转移常数(Ktrans )、血管外细胞外间隙容积比(Ve )、速率常数(Kep )值与直肠癌临床病理学特征的相关性。方法通过对82例经病理证实的直肠癌患者扩散加权成像(DWI)及动态对比增强磁共振成像(DCE-MRI)图像进行回顾性分析,获得 ADC 值及定量参数 Ktrans 、Kep 、Ve 值,进一步将这些参数与肿瘤的分化程度、Dukes 分期及有无淋巴结转移进行相关性分析。结果直肠癌的 ADC 值随肿瘤分化程度的降低和 Dukes 分期的增加而减低(P 值均<0.01)。定量参数 Ktrans 、Ve 值随肿瘤分化程度的减低而升高(P 值均<0.01);Ktrans 、Kep 值则随 Dukes 分期的增加而升高(P 值均<0.01)。ADC 值及 Ktrans 值与淋巴结转移均具有统计学相关性(P <0.01)。结论DWI 的 ADC 值及 DCE-MRI的定量参数 Ktrans 、Ve 、Kep 值与直肠癌的临床病理学特征存在一定的相关性,这些参数不仅可以作为直肠癌影像学生物标记物,而且能够为预测肿瘤的恶性程度提供一定的参考价值。     

Targeted biopsy based on ADC map in the detection and localization of prostate cancer: A feasibility study

Purpose:

To investigate the feasibility of targeted biopsy based on an apparent diffusion coefficient (ADC) map in the detection and localization of prostate cancer.

Materials and Methods:

This study included 288 consecutive patients with high or increasing serum prostate‐specific antigen (PSA) levels who underwent prostatic magnetic resonance imaging (MRI) examination with an ADC map. Four core‐targeted biopsies of low ADC lesions were performed under transrectal‐ultrasound guidance with reference to ADC map. The positive predictive values (PPVs) of low ADC lesions were calculated and compared for the peripheral zone (PZ), transition zone (TZ), and anterior portion, respectively. Comparisons of ADC values and sizes between malignant and nonmalignant lesions were also performed.

Results:

A total of 313 low ADC lesions were detected in 195 patients and sampled by targeted biopsies. The PPVs were 55.3% (95% confidence interval [CI]: 50–61) in total, 61.0% (95% CI: 53–69) for PZ, 50.6% (95% CI: 43–58) for TZ, and 90.9% (95% CI: 81–100) for the anterior portion. The most common nonmalignant pathology of low ADC lesions was hyperplasia, followed by chronic prostatitis. There were significant differences in ADC values and sizes between malignant and nonmalignant low ADC lesions.

Conclusion:

Targeted biopsies could be capable of detecting cancers well wherever they may be in the prostate, although the PPVs varied depending on the location of low ADC lesions. J. Magn. Reson. Imaging 2013;37:1168–1177. © 2012 Wiley Periodicals, Inc.     

Detection of apparent restricted diffusion in healthy rat brain at short diffusion times

The application of bipolar diffusion sensitizing gradient pulses to significantly reduce the diffusion time is described. This approach is combined with the rapid U-FLARE imaging sequence. Three diffusion-sensitized types of experiments are compared and their suitability for detecting restricted diffusion is discussed. Experiments using a modification of the diffusion weighting by varying the diffusion time between 1.6 and 6.0 ms obtained nonmonoexponential signal attenuation curves from both healthy brains and postmortem. This behavior is indicative of restricted diffusion, but as it is detectable only at short diffusion times, in contrast to a restriction due to impermeable barriers, we have termed this “apparent restriction”.     

基于全瘤容积测量的ADC值直方图在前列腺癌的诊断价值

目的 探讨全瘤容积测量的表观扩散系数(ADC)值直方图在诊断前列腺癌的价值,筛选出最佳诊断参数值.方法 回顾分析经穿刺活检或手术病理证实的前列腺癌31例,良性前列腺增生结节35例,治疗前均行扩散加权成像(DWI)检查,b=0、1500 s/mm2.测量全瘤的ADC值直方图参数,包括ADC平均值(ADCmean)、ADC中位数(ADCmedian)、ADC第10百分位数(ADC10th)、ADC第25百分位数(ADC25th)、ADC第50百分位数(ADC50th)、ADC第75百分位数(ADC75th)、ADC第90百分位数(ADC90th)、偏度值及峰度值.分析比较2组患者的直方图参数值及其诊断效能.结果 前列腺癌组的ADCmean、ADCmedian、ADC10th、ADC25th、ADC50th、ADC75th、ADC90th均低于良性前列腺增生组(P值均<0.01),2组疾病的偏度值和峰度值差异无统计学意义(P值均>0.05).ADCmean、ADCmedian、ADC10th、ADC25th、ADC50th、ADC75th、ADC90th诊断前列腺癌的受试者工作特征(ROC)曲线的曲线下面积(AUC)均>0.78,其中ADC10th诊断效能最佳,其AUC为0.82,最佳截断点值为0.27×10-3 mm2/s,敏感性和特异性分别为78.4％和83.3％.结论 全瘤容积测量的 ADC 值直方图诊断前列腺癌具有较大价值,可鉴别前列腺癌和良性前列腺增生结节,其中 ADC10th 诊断效能最高.     

Comparison and reproducibility of ADC measurements in breathhold, respiratory triggered, and free-breathing diffusion-weighted MR imaging of the liver

Purpose

To compare and determine the reproducibility of apparent diffusion coefficient (ADC) measurements of the normal liver parenchyma in breathhold, respiratory triggered, and free‐breathing diffusion‐weighted magnetic resonance imaging (DWI).

Materials and Methods

Eleven healthy volunteers underwent three series of DWI. Each DWI series consisted of one breathhold, one respiratory triggered, and two free‐breathing (thick and thin slice acquisition) scans of the liver, at b‐values of 0 and 500 s/mm². ADCs of the liver parenchyma were compared by using nonparametric tests. Reproducibility was assessed by the Bland–Altman method.

Results

Mean ADCs (in 10^?3 mm²/sec) in respiratory triggered DWI (2.07–2.27) were significantly higher than mean ADCs in breathhold DWI (1.57–1.62), thick slice free‐breathing DWI (1.62–1.65), and thin slice free‐breathing DWI (1.57–1.66) (P < 0.005). Ranges of mean difference in ADC measurement ± limits of agreement between two scans were ?0.02–0.05 ± 0.16–0.24 in breathhold DWI, ?0.14–0.20 ± 0.59–0.60 in respiratory triggered DWI, ?0.03–0.03 ± 0.20–0.29 in thick slice free‐breathing DWI, and ?0.01–0.09 ± 0.21–0.29 in thin slice free‐breathing DWI.

Conclusion

ADC measurements of the normal liver parenchyma in respiratory triggered DWI are significantly higher and less reproducible than in breathhold and free‐breathing DWI. J. Magn. Reson. Imaging 2008;28:1141–1148. © 2008 Wiley‐Liss, Inc.

     

ADC值联合肝纤四项对肝纤维化分期的评估

目的 评价MRI扩散加权成像(DWI)联合肝纤四项对肝纤维化评价的准确性.方法 将弥漫性肝病行腹部MRI检查(包括DWI)的患者30例作为研究对象.依炎症活动度(G)、纤维化程度(S)分级,将患者分为G0S0期、G1(S1～S2)期、G2(S1～S3)期、G3(S2～S4)期和G4S4期,分析扩散敏感系数(b值)分别为600 s/mm2和800 s/mm2时,不同病理分期患者表观扩散系数(ADC)值的变化;同时检测患者血清中透明质酸(HA)、Ⅲ型前胶原(PCⅢ)、Ⅳ型胶原(C-Ⅳ)和层黏连蛋白(LN)的变化,结合ADC值进行分析.结果 随肝纤维化程度加重,ADC值依次降低;随ADC值的变化,血清肝纤四项指标水平也呈现不同的变化.结论 ADC值联合血清肝纤维化指标能够准确评估肝纤维化分期.