磁共振DWI及动态增强扫描在前列腺疾病诊断中的价值

目的探讨磁共振扩散加权成像(DWI)和动态增强扫描(DCE-MRI)在前列腺疾病中的诊断价值。方法经穿刺活检或手术病理证实的20例前列腺癌及31例前列腺增生(BPH)患者进行了MR常规扫描、DWI和DCE-MRI扫描,测量病变的表观扩散系数(ADC)值,观察病灶常规MRI、DWI和动态增强MRI特征,绘制信号强度-时间曲线(SI-T曲线),SI-T曲线分成3型:Ⅰ型为信号强度早期增高后仍持续增高;Ⅱ型为信号强度早期增高后出现平台期;Ⅲ型为信号强度早期增高后出现下降期。经方差分析比较不同组织和病灶间差异。结果经DCE-MRI检查,20例前列腺癌患者中17例病灶区呈Ⅲ型曲线,2例呈Ⅱ型曲线,1例呈Ⅰ型曲线;31例前列腺增生患者中26例呈Ⅰ型曲线,4例呈Ⅱ型曲线,1例呈Ⅲ型曲线。前列腺癌组与BPH组的SI-T曲线类型分布的差异有统计学意义(P<0.01)。20例前列腺癌病灶于DWI上为高信号,于ADC图上呈明显低信号,ADC值为(1.18±0.08)×10-3 mm2/s,未被癌组织侵及的外围叶于DWI、ADC图上均呈等信号,ADC值为(2.67±0.09)×10-3 mm2/s;31例前列腺增生患者中央叶和外围叶于DWI、ADC图上均呈等信号,ADC值分别为(1.87±0.07)×10-3 mm2/s、(2.64±0.11)×10-3mm2/s。除前列腺增生的外围叶与未被癌组织侵及的外围叶之间差异无统计学意义(P>0.05)外,前列腺增生、前列腺癌、前列腺增生的外围叶和未被癌组织侵及的外围叶各组之间差异均有统计学意义(P<0.05)。DCE-MRI和DWI联合应用在前列腺癌诊断的敏感度、特异度和准确度均达80%以上。结论 DCE-MRI、DWI在前列腺癌和前列腺增生中具有特征性影像学表现,2种方法联合应用提高了MRI诊断前列腺癌的诊断和分期准确率。     

Combined diffusion-weighted and dynamic contrast-enhanced MRI for prostate cancer diagnosis--correlation with biopsy and histopathology

PURPOSE: To determine whether the combination of diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI provides higher diagnostic sensitivity for prostate cancer than each technique alone. MATERIALS AND METHODS: Fourteen patients with a clinical suspicion of prostate cancer underwent endorectal MRI on a 1.5T scanner prior to transrectal ultrasound (TRUS)-guided biopsies. The average values of the apparent diffusion coefficient (ADC, calculated from b-values of 0 and 600), K(trans), v(e), maximum gadolinium (Gd) concentration, onset time, mean gradient, and maximum enhancement were determined. Correlation with histology was based on biopsy (six patients) and prostatectomy specimen (eight patients) results. The Tukey-Kramer test was used for statistical analysis. RESULTS: The average values of all MRI parameters, except v(e) and maximum Gd concentration, showed significant differences between tumor and normal prostate. The sensitivity and specificity values were respectively 54% (35-72%) and 100% (95-100%) for the ADC data, and 59% (39-77%) and 74% (63-83%) for the DCE data. When both ADC and DCE results were combined, the sensitivity increased to 87% (68-95%) and specificity decreased to 74% (62-83%). CONCLUSION: All but two DW- and DCE-MRI parameters showed significant differences between tumor and normal prostate. Combining both techniques provides better sensitivity, with a small decrease in specificity.     

3.0TDCE-MRI对宫颈癌的评估价值

目的：探讨3.0T 动态增强磁共振(DCE-MRI)对宫颈癌各组特征的评估价值。方法156例宫颈癌患者在治疗前行常规 MRI 及 DCE-MRI 扫描,在获得病理结果后将宫颈癌患者分成6组(组织学类型,分化程度,FIGO 早晚分期,淋巴结状态,肿瘤直径,年龄段)计算时间-信号强度曲线半定量参数,并利用 SPSS 及 R3.1.1软件进行统计学分析。结果鳞癌注射对比剂后30 s 的强化率(SI30s%)及最大增强斜率(Slope)均高于腺癌,FIGO 早期宫颈癌的达峰时间(TTP)低于 FIGO 晚期宫颈癌,FIGO 早期宫颈癌的 Slope 高于 FIGO 晚期宫颈癌,其余各项分组的各参数之间无明显统计学差异。结论3.0T DCE-MRI 的半定量参数可以有效鉴别宫颈鳞癌与腺癌及 FIGO 早/晚分期宫颈癌,利用 Slope 鉴别宫颈鳞癌与腺癌的价值高于 SI30s%,TTP 与 Slope 鉴别 FIGO早/晚分期宫颈癌的价值相当。     

Added value of diffusion-weighted MR imaging to T2-weighted and dynamic contrast-enhanced MR imaging in T staging of gastric cancer

ObjectiveTo assess the utilization of diffusion-weighted (DW) magnetic resonance (MR) imaging in T staging of gastric cancer prospectively.MethodsFifty-one patients underwent T2-weighted (T2W), contrast-enhanced (CE) and DW MR imaging. Two radiologists independently interpreted the images for T staging of the tumors.ResultsThe overall accuracy of T staging in pT1-4 gastric cancers by T2W+CE+DW (88.2%) was significantly higher than that by T2W+CE and T2W+DW (both 76.5%, P= .031).ConclusionDW adds useful information to T2W and CE MR imaging in T staging of gastric cancer.     

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。     

DCE-MRI联合DWI诊断小肝癌的临床价值

目的 分析3.0T DCE-MRI联合DWI在小肝癌(SHCC)诊断和鉴别诊断中的价值.方法 回顾性分析59例经手术或穿刺活检病理证实的68个SHCC的3.0T MRI容积采集技术(LAVA),多期Gd-DTPA动态增强和弥散(DWI)影像特点.结果 SHCC在Gd-DTPA动态强化及DWI的影像学表现.68个SHCC病灶中,94.1％(64/68)在DWI呈高信号,ADC呈低信号;5.9％(4/68)肝硬化背景明显者呈略高信号,ADC图呈略低信号.平扫T1WI86.8％(59/68)病灶表现为低信号,8.8％(6/68)表现为等信号,4.4％(3/68)表现为高信号.Gd-DTPA动态强化,75％(51/68)病灶动脉期呈高信号、门脉期及平衡期呈低信号,8.8％(6/68)病灶动脉期及门脉期呈高信号、平衡期呈低信号,11.8％ (8/68)病灶动脉期强化呈稍高信号、门脉期及平衡期呈等信号,4.4％(3/68)病灶动脉期及门脉期呈无强化等信号、平衡期呈稍低信号.结论 小肝癌在DWI(b=500)上表现为高信号,绝大多数小肝癌在MR动态增强图像上表现为动脉期明显强化.因此,联合DWI和DCE-MRI明显有助于提高小肝癌的诊断和鉴别诊断.     

侵袭性三阴性乳腺癌动态增强和扩散加权MRI的特点:与其他类型乳腺癌对比

摘要目的通过与ER+/HER2-(ER+)和HER2+乳腺癌对比在动态增强、扩散加权MRI中的表现,明确侵袭性三阴性乳腺癌的MRI特征。方法共269例侵袭性乳腺癌病人、271个病灶纳入研究。由2名影像科医师回顾性分析DCE-MRI上病变的形态学和动态增强扫描特征,以及DWI对肿瘤检出率,并测量各个病灶的ADC值。     

Triple-negative invasive breast cancer on dynamic contrast-enhanced and diffusion-weighted MR imaging: comparison with other breast cancer subtypes

Objectives

To determine the MRI features of triple-negative invasive breast cancer (TNBC) on dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted MR imaging (DWI) in comparison with ER-positive/HER2-negative (ER+) and HER2-positive cancer (HER2+).

Methods

A total of 271 invasive cancers in 269 patients undergoing preoperative MRI and surgery were included. Two radiologists retrospectively assessed morphological and kinetic characteristics on DCE-MRI and tumour detectability on DWI. Apparent diffusion coefficient (ADC) values of lesions were measured. Clinical and MRI features of the three subtypes were compared.

Results

Compared with ER+ (n?=?119) and HER2+ (n?=?94), larger size, round/oval mass shape, smooth mass margin, and rim enhancement on DCE-MRI were significantly associated with TNBC (n?=?58; P??3?mm²/s) of TNBC (1.03) was higher than the mean ADC values for ER+ and HER2+ (0.89 and 0.84; P?P?=?0.099). Tumour size (P?=?0.009), mass margin (smooth, P?P?=?0.020), and ADC values (P?=?0.002) on DCE-MRI and DWI were independent features of TNBC.

Conclusions

In addition to the morphological features, higher ADC values on DWI were independently associated with TNBC and could be useful in differentiating TNBC from ER+ and HER2+.

Key Points

? Triple-negative breast cancers (TNBC) lack oestrogen/progesterone receptors and HER2 expression/amplification. ? TNBCs are larger, better defined and more necrotic than conventional cancers. ? On MRI, necrosis yields high T2-weighted signal intensity and ADCs. ? High ADC values can be useful in diagnosing TNBC.     

3T磁共振高分辨动态增强诊断小乳癌的应用研究

目的:探讨磁共振高分辨动态增强检查对小乳腺癌诊断的临床应用价值。方法:回顾性分析病理证实的20例(21个病灶)小乳腺癌(最大径≤2cm)的MRI高分辨动态增强检查的形态学及血流动力学特征。结果:小乳腺癌的特征性表现为形态不规则或分叶、边缘不规则或者毛刺、不均匀环形强化的肿块样病变以及局灶、不均匀或簇集样强化的非肿块病变,时间-信号强度曲线:平台型7例(33.3%),流出型14例(66.7%)。对侧对称部位正常乳腺为逐渐轻度强化,时间-信号强度曲线均为持续型。结果显示小乳腺癌灶与正常乳腺组织之间的血流动力学变化有显著差异。结论:3T磁共振高分辨动态增强检查能够提供清晰、丰富的形态学及血流动力学信息,对小乳腺癌的诊断和鉴别诊断具有重要价值。     

Axillary lymph node metastases in breast cancer: preoperative detection with dynamic contrast-enhanced MRI

Metastatic involvement of axillary lymph nodes is one of the most important prognostic variables in breast cancer. The aim of our work was to study the value of dynamic contrast-enhanced MR imaging in revealing axillary lymph node metastases from breast cancer. A total of 65 patients with invasive breast cancer treated with axillary lymph node dissection were preoperatively evaluated by MRI. T1-weighted dynamic contrast-enhanced 3D images were acquired using a coil covering the breast and the axilla. The dynamic contrast enhancement, size, and morphology of the axillary lymph nodes were registered. Histopathological examination revealed axillary lymph node metastases in 24 patients. When using a signal intensity increase in the lymph nodes of > 100 % during the first postcontrast image as a threshold for malignancy, 57 of 65 patients were correctly classified (sensitivity 83 %, specificity 90 %, accuracy 88 %). These results were not improved when lymph node size and morphology were used as additional criteria. Axillary lymph nodes can be evaluated as a part of an MR-mammography study without substantial increase in examination time, and provide the surgeon with knowledge about the localization of possible metastatic lymph nodes. Received: 25 February 1999; Revised: 3 August 1999; Accepted: 27 January 1999     

三维肝脏容积超快速采集MR动态增强扫描及其定量数据对子宫内膜癌的诊断价值

目的 探讨子宫内膜癌MRI动态增强数据及曲线类型对诊断、分期的价值.方法 回顾性分析经分段诊断性刮宫证实为子宫内膜癌的55例患者MRI动态增强表现,绘制病灶区及邻近正常组织的动态增强时间-信号曲线(TIC),测量及计算动态早期相对信号增强率(ARSI％)、最大相对信号增强率(MRSI％)和总体相对信号增强率(SER％),并对曲线分型,对不同征象分组间MRSI％的差异行独立样本t检验,ARSI％和SER％的差异行Mann-Whitney U检验.结果 病灶动态增强扫描早期信号强度为716 ±215,正常组织为894±355,差异有统计学意义(t=-2.911,P＜0.01);病灶动态增强扫描晚期强化率为803±289,正常组织为1111±289,差异有统计学意义(t=-4.926,P＜ 0.01).低分化组16例患者ARSI％(中位数为1.07％)高于中高分化组的39例(中位数为0.36％),深肌层浸润组19例的ARSI％(中位数为0.76％)高于无或浅肌层浸润组36例患者(中位数为0.32％),宫颈受累组27例患者的ARSI％(中位数为0.84％)高于未受累组的28例患者(中位数为0.25％),宫颈受累组SER％(中位数为2.90％)高于未受累组(中位数为1.40％),宫旁及其他组织受侵、转移组7例患者的SER％(中位数为2.03％)高于局限在子宫内组48例患者(中位数为1.60％),差异有统计学意义(Z值分别为-2.038、-2.260、-2.172、-2.695及-2.621,P值均＜0.05).病灶区动态增强曲线:I型13例(13/55),Ⅱ型22例(22/55),Ⅲ型9例(9/55),Ⅳ型11例(11/55).结论 MR动态增强扫描能定量分析子宫内膜癌在各阶段的强化特点,根据其TIC及定量数据可以进一步判断预后、指导分期.     

Visualization of prostate cancer using dynamic contrast-enhanced MRI: comparison with transrectal power Doppler ultrasound

This study was designed to assess the efficacy of dynamic contrast-enhanced MRI (DCE-MRI), in comparison with power Doppler ultrasound (PDUS), for visualizing prostate cancer. 111 men suspected of having prostate cancer underwent imaging before undergoing octant biopsy. Subsequently, 31 cancer-positive patients were enrolled in this study. DCE-MRI was obtained using a three-dimensional fast-field echo sequence, which assured wide coverage of the prostate gland. The transrectal PDUS were scored according to the degree of power Doppler flow signals. The time intensity curve types for the DCE-MRI and the PDUS scores were compared with the histopathologic results for each region. The time intensity curves were correlated significantly with PDUS scores (p<0.001). Using PDUS, the overall sensitivity, specificity and accuracy of cancer visualization in peripheral zones were 69%, 61% and 66%, respectively. Using DCE-MRI, the corresponding values were 87%, 74% and 82%. In the inner gland, using PDUS, the overall sensitivity, specificity and accuracy were 68%, 94% and 83%, respectively. Using DCE-MRI, the corresponding values were similar (68%, 86% and 78%). DCE-MRI was significantly more sensitive than transrectal PDUS in peripheral zones (p<0.05). In conclusion, both transrectal PDUS and DCE-MRI can be used to demonstrate hypervascularity in many prostate cancers. DCE-MRI was significantly more sensitive than PDUS for visualizing of prostate cancers without loss of specificity in the peripheral zone.     

Prostate cancer detection with 3-T MRI: comparison of diffusion-weighted and T2-weighted imaging

OBJECTIVE: To compare the clinical value of diffusion-weighted (DW) and T2-weighted (T2W) imaging in detecting prostate cancer using a 3-Tesla (3T) magnetic resonance (MR) system. MATERIALS AND METHODS: Thirty-seven patients with suspected prostate cancer underwent T2W and DW imaging at 3T using an 8-channel phased-array coil. These images and apparent diffusion coefficient (ADC) maps were read retrospectively and blindly. The results were compared with histopathologic findings, and receiver operating characteristic (ROC) analysis was used to compare the cancer detection performance of T2W and DW imaging. RESULTS: The areas under the ROC curves for DW imaging and T2W imaging were 0.89 and 0.82, respectively. The performance of DW imaging in prostate cancer detection was significantly better than that of T2W imaging (P=0.0371). CONCLUSION: With a 3T MR system, the performance of DW imaging in detecting prostate cancer was better than that of T2W imaging. DW imaging appears to be a robust and reliable method to examine the whole prostate within an acceptable scan time in clinical settings.     

Predictive value of T2-weighted imaging and dynamic contrast-enhanced MRI for assessing cervical invasion in patients with endometrial cancer: a meta-analysis

PurposeTo obtain the diagnostic accuracy of T2-weighted imaging (T2WI), and dynamic contrast-enhanced MRI (DCE-MRI) in the preoperative assessment of cervical invasion in patients with endometrial cancer (EC).MethodsDatabases including PubMed, Embase, Cochrane Library, Web of Science, and Clinical Trials were searched for relevant articles published from January 2000 to August 2020. Pooled estimation data were obtained by statistical analysis.ResultsIn total, 24 articles were included. For assessing cervical invasion of EC, the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) for T2WI were 0.70 (0.61–0.77), 0.92 (0.89–0.94), 8.7 (6.5–11.6), 0.33 (0.25–0.43), 26 (17–41), and 0.92 (0.89–0.94), respectively. For DCE-MRI, the pooled sensitivity, specificity, PLR, NLR, DOR, and AUC were 0.75 (0.60–0.85), 0.95 (0.89–0.98), 14.7 (6.6–32.9), 0.27 (0.16–0.44), 55 (18–165), and 0.92 (0.89–0.94), respectively; for T2WI combined with DCE-MRI, they were 0.58 (0.41–0.73), 0.98 (0.95–0.99), 28.1 (12.8–62.1), 0.43 (0.30–0.63), 65 (29–146), and 0.94 (0.91–0.96), respectively.ConclusionsDCE-MRI demonstrated higher diagnostic performance than T2WI in the prediction of cervical invasion in patients with EC. T2WI combined with DCE-MRI improved the pooled specificity, PLR, DOR, and AUC compared to T2WI alone or DCE-MRI alone.     

Diffusion-weighted MRI provides additional value to conventional dynamic contrast-enhanced MRI for detection of hepatocellular carcinoma

The purpose of this study was to evaluate the accuracy of diffusion-weighted magnetic resonance imaging (DW-MRI) in differentiating HCC from benign cirrhotic lesions compared with conventional dynamic contrast-enhanced MRI. Fifty-five patients with cirrhosis underwent conventional and DW-MRI at 1.5 Tesla. Signal intensity ratios (SI_ratio) of solid liver lesions to adjacent hepatic parenchyma were measured for b0, b100, b600 and b1000, and the apparent diffusion coefficients (ADC) were calculated. In 27 patients, imaging results were compared to histopathology, and in 28 patients, to imaging follow-up. Based on predetermined thresholds, sensitivity and specificity of DW-MRI and conventional MRI were compared. SI_ratio was significantly different between malignant and benign lesions at all b-values (P?<?0.0001). No significant difference in ADC was seen (P?=?0.47). For detection of malignant lesions, DW-MRI with b600-SI_ratio yielded a sensitivity of 95.2% compared to 80.6% for conventional MRI (P?=?0.023) and a specificity of 82.7% compared to 65.4% (P?=?0.064). The improved accuracy was most beneficial for differentiating malignant lesions smaller than 2 cm. DW-MRI with b600-SI_ratio improved the detection of small HCC and the differentiation of pseudotumoral lesions compared with conventional MRI.     

基于动态对比增强MRI的肿瘤血流动力学及形态学特征预测乳腺癌术后复发时间的价值

目的探讨乳腺癌患者术前经常规动态对比增强MRI(DCE-MRI)扫描后获得的肿瘤血流动力学及形态学特征预测术后复发时间的价值。方法回顾性分析2012年11月至2014年12月辽宁省肿瘤医院术后复发的乳腺癌患者58例,依据复发时间分为早期复发(术后≤2年)组33例,晚期复发(术后>2年)组25例。所有患者均在术前行常规DCE-MRI扫描,通过计算机提取肿瘤三维容积内的血流动力学特征及在每一个期相下的肿瘤形态学特征及纹理特征。早期复发组和晚期复发组患者间计数资料和计量资料的比较分别采用Fisher精确概率法和Mann-Whitney U检验,绘制受试者操作特征(ROC)曲线,应用多元logistic回归计算特征联合预测早期复发与晚期复发的诊断效能。应用Kaplan-Meier法分析生存预后,并用Log-Rank检验比较各组生存曲线的差异。结果早期复发组和晚期复发组患者背景实质强化、病灶边缘、病灶内部强化特征、病灶形态、时间信号曲线类型和全乳血管增加程度的差异均无统计学意义(P均>0.05);2组患者的对比剂最大浓度值(Max Conc)、时间信号曲线下面积(AUC)及时间信号曲线最大斜率值(Max Slope)值差异有统计学意义(P<0.05)。对比分析8期DCE-MRI影像组学特征参数,第3期形态特征参数球度(sphericity)在早期复发与晚期复发组间差异有统计学意义(P=0.03)。AUC、Max Conc、Max Slope和第3期形态特征参数球度预测早期与晚期复发的ROC曲线下面积分别为0.664、0.659、0.684、0.670,上述4个参数联合预测的ROC曲线下面积为0.765,特异度为63.6%,灵敏度为84.0%,预测效能高于单变量。58例患者随访时间17~64个月,中位随访时间47个月。早期复发组的无进展生存和总生存均明显低于晚期复发组,差异有统计学意义(P<0.05)。结论基于术前无创性常规DCE-MRI获取的肿瘤血流动力学特征联合形态学特征预测乳腺癌患者的术后复发时间有一定的价值。