磁共振弥散加权成像、T2加权成像及动态增强联合运用对前列腺癌的诊断价值

目的 探讨磁共振弥散加权成像(DWI)、T2加权像(T2WI)及动态增强(DCE)联合应用对前列腺癌的诊断价值.方法 100例前列腺疾病中前列腺癌49例和非癌病例51例(包括46例前列腺增生、3例外周带炎症及2例前列腺结核).所有病例在常规MR检查基础上加扫DCE及DWI序列,DWI的b值为800 s/mm2.比较T2WI、DCE、DWI及三者联合诊断前列腺癌的敏感性;统计分析前列腺组织与非癌组织的ADC值是否存在差异.结果 在DWI图像上,前列腺癌多呈明显高信号,6例局限于中央带前列腺癌得到正确诊断.前列腺癌组织的平均ADC值为(0.96±0.22)×10-3mm2/s,前列腺增生组织的平均ADC值为(1.56±0.23)×10-3mm2/s,两者之间有统计学差异(P＝0.001),但ADC值有小部分重叠.T2WI、DCE、DWI及三者联合诊断前列腺癌的敏感性分别为85.7%、87.8%、93.9%、100%.结论 T2WI、DCE及DWI三者联合应用可以弥补各自的缺点,提高前列腺癌诊断的敏感性.     

MRI对锥切术后残余宫颈的评估价值

目的 探讨MRI表观扩散系数（ADC）和时间-信号强度曲线（TIC）对锥切术后残余宫颈的评估价值。方法 回顾性收集因宫颈病变行宫颈锥切术及子宫切除术的50例病人的影像和病理资料,病人均行T1WI、T2WI、扩散加权成像（DWI）和动态增强MRI检查。将病灶根据病理结果分为残留癌灶和阴性切缘,测量残留癌灶和阴性切缘的ADC值并分析TIC类型。以手术病理结果为金标准,计算MRI对残余宫颈癌灶的诊断敏感度、特异度、准确度、阳性预测值和阴性预测值。采用t检验和Fisher确切概率检验比较残留癌灶和阴性切缘间ADC值和TIC类型的差异。结果 残留癌灶MRI表现为稍低T1、稍高T2信号,DWI上表现为高信号,扩散受限,动态增强扫描早期强化明显,延迟期强化程度低于正常宫颈,TIC均呈快进快出型（Ⅲ型）。阴性切缘MRI表现为等T1、等或稍高T2信号,DWI上表现为等或稍高信号,扩散不受限,动态增强扫描表现为持续性明显强化,TIC主要呈流入型（Ⅰ型）。21例病人宫颈切缘残留癌灶,29例呈阴性切缘。MRI对残留癌灶诊断敏感度较低（19.0%）,特异度较高（93.1%）,准确度62.0%,阳性预测值66.7...     

3.0T磁共振扩散加权成像在子宫内膜癌诊断中的价值

目的 探讨3.0T MR扩散加权成像(DWI)在子宫内膜癌诊断中的临床应用价值.方法 对48例子宫内膜癌患者和20例无子宫内膜病变者行盆腔T2WI和DWI,由2名MRI诊断医师采用盲法随机进行MRI阅片后,采用5分制评分,以受试者工作特征曲线(ROC)对比分析单纯T2WI与DWI结合T2WI诊断子宫内膜癌的敏感性和特异性,并对内膜癌和正常内膜的表观扩散系数(ADC)值进行定量分析.结果 2名医师单纯应用T2WI与DWI结合T2WI检出子宫内膜癌的ROC曲线下面积(Az)值分别为0.831与0.944、0.877与0.954,2名医师DWI结合T2WI对内膜癌诊断的准确性均高于单纯应用T2WI(P<0.05).Kappa一致性检验表明2名医师具有良好的一致性(Kappa值分别为0.843和0.898,P<0.01).子宫内膜癌和正常内膜的ADC值分别为(0.954±0.139)×10-3mm2/s、(1.468±0.161)×10-3mm2/s,子宫 内膜癌与正常内膜的ADC值间差异有统计学意义(t=-13.217,P<0.01).结论 3.0T MR-DWI作为常规T2WI的补充检查序列可以明显提高对子宫内膜癌的检出率.     

MRI不同序列对子宫内膜癌定性和定量诊断的价值

目的比较DWI与T 2WI诊断子宫内膜癌敏感性以及测量病变大小准确性的差别,以更好地指导临床医师阅读MRI。方法34例子宫内膜癌患者术前均已行多模态3.0T MRI检查,以术后病理为金标准,比较这两种序列诊断EC的灵敏度,同时分别比较两种序列测量癌灶上下径、左右径与术后径线的差别。结果DWI诊断子宫内膜癌的敏感性(97%)高于T 2WI(80%),DWI所测得癌灶上下径、左右径与术后均有差别(P上下径=0.002,P左右径=0.002),T 2WI均无差别(P上下径=0.579,P左右径=0.261)。结论DWI可明显提高MRI诊断子宫内膜癌的敏感性,而T 2WI测量癌灶大小的准确性更高。     

3.0T磁共振DWI结合T2加权成像诊断前列腺癌侵犯膀胱

目的 探讨T2WI及DWI 2种成像序列对前列腺癌(PCa)侵犯膀胱的诊断价值.方法 68例经病理证实的PCa患者在行3.0T MR前列腺常规和DWI(b值分别为0、800 s/mm2)扫描后被诊断为PCa侵犯膀胱,所有患者均行膀胱镜检查.分析所有PCa癌灶、受侵膀胱和未受侵膀胱壁的MRI表现,比较其ADC值.采用5分制评分,将所得结果与膀胱镜病理结果对照,用SPSS11.5分别做受试者工作特征曲线(ROC)分析比较各组方法诊断的敏感度和特异度.结果 膀胱镜检查45例(66%)患者病理证实为PCa侵犯膀胱,PCa癌灶、受侵膀胱壁和正常膀胱壁的ADC值分别为(0.931±0.098)×10-3mm2/s,(0.963±0.155)×10-3mm2/s和(1.517±0.103)×10-3mm2/s,受侵膀胱壁的ADC值明显低于正常膀胱壁(P＜0.05),而PCa癌灶和受侵膀胱壁的ADC值之间无明显差异.分别应用T2WI和DWI诊断PCa侵犯膀胱的ROC曲线下面积(AUC)明显低于联合2种成像方法(P＜0.05).结论 PCa侵犯膀胱的ADC值明显低于正常膀胱壁;联合应用DWI和T2WI诊断PCa侵犯膀胱优于单独使用DWI或T2WI.     

磁共振扩散加权成像对不可触及隐睾诊断价值

目的:评价DWI序列是否可增加不可触及隐睾的检出率。方法:回顾性分析36例经病理证实的隐睾患者影像临床资料,其中单侧隐睾34例,双侧隐睾2例。所有患者术前均行常规(T1WI、T2WI)及DWI检查,采用双盲法评估并计算MR常规序列、DWI及常规序列+DWI对于不可触及隐睾诊断的敏感性、特异性、准确性、阳性预测值及阴性预测值。结果:隐睾表现为边缘清晰的椭圆形长T1、长T2信号,DWI上呈高信号。联合应用T1WI、T2WI及DWI的敏感性、准确性分别为90.9%与91.7%,均高于单独应用T1WI、T2WI或DWI(P<0.05)。结论:联合应用T1WI、T2WI与DWI序列有助于提高不可触及隐睾的准确定位和诊断。     

弥散加强成像对静脉性脑梗死诊断价值

目的观察静脉性脑梗死的扩散加权成像(DWI)影像表现,比较DWI与T2WI的敏感性。方法回顾性分析32例经MR或DSA确诊的脑静脉窦血栓(CVST)患者的影像资料,所有患者全部伴有静脉性脑梗死。所有患者均在症状后1~48h行首次T1WI、T2WI、DWI、MRV序列检查。其中,25例进行了DSA检查。观察DWI和T2WI发现高信号梗死区的数量。并测量梗死区的表观扩散系数(ADC值)。结果静脉性脑梗死的急性期,DWI敏感性为90%,高于T2WI(32%)(P0.05)。静脉性脑梗死的亚急性期DWI的敏感性为24%低于T2WI(100%)(P0.05)。急性期静脉性梗死区的ADC值为5.32±1.03×10~(-4)mm~2/s低于亚急性期的ADC值(11.48±3.13×10~(-4)mm~2/s)(P0.05)。结论 DWI对诊断静脉性脑梗死有补充价值。在静脉性脑梗死的急性期,DWI序列的作用突出,此时T2WI敏感性较低。通过测量梗死区的ADC值,我们能判断静脉性脑梗死中脑水肿的性质。     

3.0 T磁共振扩散加权成像在直肠癌诊断中的价值

目的 探讨MR扩散加权成像(DWI)在直肠癌诊断中的临床应用价值.资料与方法对50例直肠癌患者和17名无直肠病变的自愿者行盆腔T2WI和DWI,由两名放射诊断医师采用肓法随机进行MRI阅片后对比分析单纯T2WI与T2WI结合DWI对直肠癌诊断的特异性和敏感性差异,并对直肠癌和正常肠壁的表观扩散系数(ADC)值进行定量分析.结果两名医师单纯应用T2WI与T2WI结合DWI检出直肠癌的ROC曲线下面积(Az)值分别为0.873与0.978(P＜0.05)、0.905与0.986(P＜0.05).Kappa一致性检验表明两名医师具有良好的一致性(Kappa值分别为0.860和0.828,P＜0.05).直肠癌和其癌周正常肠壁ADC值的平均值±标准差分别为(0.93±0.14)×10-3 mm2/s、(1.40±0.17)×10-3 mm2/s,直肠癌与正常肠壁的ADC值间差异有统计学意义(t=17.43,P＜0.01).结论 3.0 T MR DWI能较直观地显示直肠癌,其作为常规T2WI的补充检查序列可以明显提高对直肠癌的检出率.     

磁共振DWI结合T_2WI在前列腺疾病诊断中的价值

目的：探讨磁共振DWI结合T2WI在前列腺良恶性疾病诊断中的价值。方法：53例经组织病理学及随访证实的前列腺疾病患者,其中前列腺癌（PCa）15例,前列腺增生（BPH）38例,行磁共振平扫及DWI,测量其表观扩散系数（ADC）及病灶与周围正常外围带ADC值的相对比值,经2名有经验的医师进行双盲阅片,比较T2WI及DWI结合T2WI对PCa、BPH的定性诊断准确率。结果：T2WI对PCa、BPH的定性诊断准确率分别为73.3%、65.8%,DWI结合T2WI对PCa、BPH的定性诊断准确率分别为86.7%、92.1%。结论：DWI结合T2WI能提高前列腺疾病的定性诊断准确率,DWI及ADC值在一定程度上有助于前列腺良恶性病变的鉴别。     

MR扩散加权成像对颈髓急慢性损伤的诊断价值

目的探讨急慢性颈髓损伤磁共振扩散加权成像(DWI)的特点及其临床应用价值。方法对临床诊断为脊髓型颈椎病患者38例(CSM组)、急性颈髓外伤患者16例(外伤组)以及正常健康志愿者15例(对照组)采用单次激发自旋回波-平面回波序列行颈髄DWI检查,分析各例DWI图像特点,测量表观扩散系数(ADC)值。结果 CSM组:38例中T2WI颈髓出现高信号者20例,颈髓受压部位ADC值表现异常者30例(78.9%),其中27例ADC值高于正常组ADC值,3例ADC值降低,DWI图像表现为低信号或等信号;外伤组16例中ADC值表现异常者为14例(87.5%),10例常规T2WI颈髓受伤部位出现局限性异常信号,呈高信号或混杂信号,损伤部位ADC值有明显降低,DWI表现为高或混杂信号,6例T2WI及DWI信号无改变者,4例损伤部位ADC值降低。两组ADC值与正常对照组比较均有统计学差异。结论 CSM组和外伤组DWI成像ADC值有不同变化,判断脊髓病变较常规T2WI具有更高的敏感性,对临床诊断及预后判断有较高价值。     

DWI结合高分辨T_2WI磁共振在子宫内膜癌分期中的价值

目的:探讨DWI结合高分辨T2WI在子宫内膜癌分期中的价值。方法:回顾性分析70例经手术病理证实的子宫内膜癌DWI及高分辨T2WI表现,测量其ADC值,判断其浸润范围,并与术后病理结果相比较。结果:DWI结合高分辨T2WI对子宫内膜癌2009FIGO分期准确性为94.3%,评价浅肌层、深肌层浸润的敏感度、特异度和准确度分别为94.5%、82.4%、94.3%和83.3%、95.3%、94.3%;评价子宫内膜癌宫颈基质浸润的敏感度、特异度和准确度分别为100%、100%和100%。结论:DWI结合高分辨T2WI磁共振能够提高子宫内膜癌浸润深度评价的准确度,有助于子宫内膜癌的诊断、分期及帮助制定治疗计划。     

Value of diffusion-weighted imaging for the prediction of prostate cancer location at 3T using a phased-array coil: preliminary results

OBJECTIVES: To retrospectively evaluate the imaging quality of diffusion-weighted imaging (DWI), compare the apparent diffusion coefficient (ADC) values for malignant and benign tissues in the peripheral zone (PZ) and transition zone (TZ), and evaluate whether T2-weighted imaging (T2WI) with DWI could improve the prediction of prostate cancer location when compared with T2WI at 3T using a phased-array coil. MATERIALS AND METHODS: Thirty-seven patients underwent T2WI and DWI before radical prostatectomy. The DWI technique with b = 0 and b = 1000 s/mm2 was used. ADC values were measured in benign and malignant tissues in the PZ or TZ. The prediction of prostate cancer location was evaluated in the PZ and TZ using T2WI and T2WI with DWI, respectively. Two readers in consensus recorded the presence of prostate cancer at magnetic resonance imaging and rated the imaging quality of DWI. RESULTS: For the prediction of 68 prostate tumors, the overall sensitivity and positive predictive value of T2WI with DWI were 84% and 86%, whereas those of T2WI were 66% and 63%, respectively (P < 0.05). The mean ADC values of malignant and benign tissues in the PZ and TZ were 1.30 +/- 0.26 and 1.96 +/- 0.20, and 1.35 +/- 0.24 and 1.75 +/- 0.23 x 10(-3)mm2/s, respectively (P < 0.01). The overall imaging quality was satisfactory or better in 97% of patients. CONCLUSION: DWI is a feasible technique that can be used for the differentiation of malignant and benign tissues in the PZ and TZ. Additionally, T2WI with DWI is superior to T2WI alone for the prediction of prostate cancer location.     

Diffusion-weighted MR imaging for the evaluation of seminal vesicle invasion in prostate cancer: initial results

PURPOSE: To evaluate the accuracy of T2-weighted (T2WI) with diffusion-weighted imaging (DWI) as compared with T2WI alone for predicting seminal vesicle invasion (SVI) of prostate cancer. MATERIALS AND METHODS: A total of 30 patients with SVI and 136 patients without SVI who underwent prostate MR imaging were included in the study. MR images were analyzed retrospectively and independently by two readers for SVI on T2WI and T2WI with DWI using a 5-point scale. RESULTS: For predicting SVI, the specificity for T2WI with DWI and for T2WI was 97% and 87%, respectively, and accuracy was 96% and 87%, respectively, as determined by the experienced reader (P < 0.01). For the less experienced reader, the specificity for T2WI with DWI and for T2WI was 96% and 81%, respectively, and accuracy was 90% and 77%, respectively (P < 0.01). The diagnostic performance of the less experienced reader with T2WI with DWI led to significant improvement of the area under the receiver operating characteristic curve (Az) as compared with T2WI alone (Az = 0.815 versus 0.696; P < 0.01). Interreader agreement showed a substantial agreement (kappa = 0.613) for T2WI, and a substantial agreement (kappa = 0.737) for T2WI with DWI. CONCLUSION: For predicting SVI, T2WI with DWI showed a better diagnostic performance than T2WI alone. Additionally, the accuracy of the less experienced reader using T2WI with DWI showed a significant improvement as compared with T2WI alone.     

3.0TMRI高b值扩散加权成像在宫颈癌分期中的应用

目的：探讨3.0T MRI 扩散加权成像(DWI)单一序列在宫颈癌诊断及分期中的应用价值。方法2名观察者分别独立分析65例宫颈癌患者术前 T2 WI、DWI 和 LAVA-Flex 动态增强图像,比较三者对宫颈癌影像学分期结果的差异,对肿瘤的 T2 WI、DWI 和 LAVA-Flex 动态增强图像进行分期效能评估。结果DWI 检测到所有的病灶,其中3例病灶在常规 T2 WI 序列未能发现,1例在动态增强图像上未能发现。DWI、T2 WI 与 LAVA-Flex 动态增强对宫颈癌总体分期准确率分别为90.8%、78.5%、87.7%。DWI 单一序列分期的准确率高于单一 T2 WI 序列(P =0.04),DWI 序列与多期动态增强序列分期准确率无显著差异(P =0.39)。结论单一的 DWI 序列在宫颈癌分期中的准确性优于单一的 T2 WI 序列,在不具备增强的条件下 DWI 有望替代 MRI 动态增强序列,对宫颈癌做出准确的分期。     

Comparison of DWI and PET/CT in evaluation of lymph node metastasis in uterine cancer

AIM: To investigate diffusion-weighted imaging (DWI) and positron emission tomography and computed tomography (PET/CT) with Ⅳ contrast for the preoperative evaluation of pelvic lymph node (LN) metastasis in uterine cancer. METHODS: Twenty-five patients with endometrial or cervical cancer who underwent both DWI and PET/CT before pelvic lymphadenectomy were included in this study. For area specific analysis, LNs were divided into eight regions: both common iliac, external iliac, internal iliac areas, and obturator areas. The classification for malignancy on DWI was a focally abnormal signal intensity in a location that corresponded to the LN chains on the T1WI and T2WI. The criterion for malignancy on PET/CT images was increased tracer uptake by the LN.RESULTS: A total of 36 pathologically positive LN areas were found in 9 patients. With DWI, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy for detecting metastatic LNs on an LN area-by-area analysis were 83.3%, 51.2%, 27.3%, 93.3% and 57.0%, respectively, while the corresponding values for PET/CT were 38.9%, 96.3%, 70.0%, 87.8% and 86.0%. Differences in sensitivity, specificity and accuracy were significant (P < 0.0005). CONCLUSION: DWI showed higher sensitivity and lower specificity than PET/CT. Neither DWI nor PET/CT were sufficiently accurate to replace lymphadenectomy.     

双参数MRI纹理分析鉴别诊断移行区前列腺癌及增生结节的价值

目的探讨双参数MRI纹理分析法在移行区前列腺癌及增生结节鉴别诊断中的应用价值。方法回顾性分析经病理证实的前列腺癌52例,增生结节39例。使用MRIcroN软件勾画病灶的范围,Matlab R2014b软件计算各纹理参数,用Fisher法选择独立纹理特征(包括方差,熵,偏度和峰度)及平均ADC值。使用两独立样本t检验评估各纹理参数及平均ADC值是否具有统计学差异。绘制受试者工作特征曲线并计算曲线下面积、敏感度和特异度。结果T 2WI前列腺癌组的方差低于增生组,熵高于增生组。ADC图前列腺癌组的方差和平均ADC值低于增生组,偏度、峰度、熵高于增生组。T 2WI熵联合ADC图熵的诊断价值最高(AUC=0.880),敏感度和特异度分别为73.7%,90.9%。结论T 2WI联合ADC图双参数纹理分析可准确区分前列腺癌与低信号增生结节,为两者的鉴别诊断提供客观、量化的依据。     

磁共振弥散加权成像对宫颈癌复发的诊断价值

目的探讨磁共振弥散加权成像对宫颈癌复发的诊断价值。方法收集宫颈癌术后在我院复查MRI检查患者121例,其中行放疗37例,以手术或穿刺病理证实复发32例,先分为复发组与未复发组,再按术后是否行放射治疗分为单纯术后组及手术加放疗组,复发组分为单纯术后复发组及手术后加放疗后复发组,分别测量术后、放疗后宫颈残端与复发肿瘤的ADC值,进行对比分析;采用DWI诊断宫颈癌复发与病理进行对照比较,以敏感性、特异性及准确率三项指标分析DWI对其复发的诊断价值。结果术后、术后放疗后与复发癌灶ADC值两两对比,差异有显著性意义,术后复发与术后放疗后复发无统计学意义;DWI成像对宫颈癌复发的敏感性、特异性及准确率分别为：100％、95．51％、96．69％。结论弥散加权成像可以作为评估宫颈癌复发的准确检查方法。     

Usefulness of apparent diffusion coefficient map in diagnosing prostate carcinoma: correlation with stepwise histopathology

PURPOSE: To elucidate the performance of apparent diffusion coefficient (ADC) map in localizing prostate carcinoma (PC) using stepwise histopathology as a reference. MATERIALS AND METHODS: Preoperative MR images of 37 patients with PC who had undergone radical prostatectomy were retrospectively evaluated. First, T2-weighted images (T2WI) alone were interpreted (T2WI reading), and then T2WI along with ADC map were interpreted (T2WI/ADC map reading). Sextant-based sensitivity and specificity, and the ratio of the detected volume to the whole tumor volume (% tumor volume) were compared between the two interpretations, and results were also correlated to Gleason's scores (GS). ADC values were correlated to histological grades. RESULTS: Sensitivity was significantly higher in T2WI/ADC map reading than in T2WI reading (71% vs. 51%), but specificity was similar (61% vs. 60%). By adding ADC map to T2WI, % tumor volume detected increased significantly in transitional zone (TZ) lesions, but not in peripheral zone (PZ) lesions. % tumor volume detected with T2WI/ADC map reading showed a positive correlation with GS of the specimens. Less differentiated PC were associated with lower ADC values and higher detectability. CONCLUSION: T2WI/ADC map reading was better than T2WI reading in PC detection and localization. This approach may be particularly useful for detecting TZ lesions and biologically aggressive lesions.     

The role of diffusion – Weighted MRI in evaluation of prostate cancer

The aim of work

To illustrate the role of T2WI combined with diffusion WI (DWI) in the evaluation of patients with prostate cancer.

Patients and methods

This prospective study included 36 patients (mean age 61) with clinical suspicion of prostate cancer using surface coil at 1.5 T MR Unit. Axial, coronal, and sagittal high resolution (HR) T2WI were performed, DWI was applied using a single-shot echo-planar imaging sequence in axial orientation. Regions of interest were drawn on ADC maps on the site of visible restricted diffusion as well as the normal tissue, then the ADC value was calculated. Considering histopathological diagnosis the standard of reference, the results of T2WI alone were compared with those of combined T2WI and DWI.

Results

In this prospective study, 36 men were examined and T2WI, DWI, ADC map and ADC values were measured. T2 low SI was detected in the peripheral zone of the prostate of 36 patients, and restricted diffusion in 31 patients.

Conclusion

Our study indicates that the addition of the ADC map and DWI to T2WI provide significantly more accurate results for prostate cancer detection and staging.     

Detection of non-palpable breast cancer in asymptomatic women by using unenhanced diffusion-weighted and T2-weighted MR imaging: comparison with mammography and dynamic contrast-enhanced MR imaging

Objective

To compare the detectability of non-palpable breast cancer in asymptomatic women by using mammography (MMG), dynamic contrast-enhanced MR imaging (DCE-MRI) and unenhanced MR imaging with combined diffusion-weighted and T2-weighted images (DWI?+?T2WI).

Methods

Forty-two lesions in 42 patients with non-palpable breast cancer in asymptomatic women were enrolled. For the reading test, we prepared a control including 13 normal and 8 benign cases. Each imaging set included biplane MMG, DCE-MRI and DWI?+?T2WI. Five readers were asked to rate the images on a scale of 0 to 100 for the likelihood of the presence of cancer and the BI-RADS category. Confidence level results were used to construct receiver operating characteristic analysis. Sensitivity and specificity were calculated for each technique.

Results

DWI?+?T2WI showed higher observer performances (area under the curve, AUC, 0.73) and sensitivity (50%) for the detection of non-palpable breast cancer than MMG alone (AUC 0.64; sensitivity 40%) but lower than those of DCE-MRI (AUC 0.93; sensitivity 86%). A combination of MMG and DWI?+?T2WI exhibited higher sensitivity (69%) compared with that of MMG alone (40%).

Conclusion

DWI?+?T2WI could be useful in screening breast cancer for patients who cannot receive contrast medium and could be used as a new screening technique for breast cancer.