磁共振弥散加权成像的表观弥散系数在直肠腺癌术前诊断中的应用

目的 探讨磁共振弥散加权成像(DWI)的表观弥散系数(ADC)在诊断直肠腺癌和评估直肠腺癌恶性程度中的应用.方法 比较82例经病理学检查确诊的直肠腺癌患者(观察组)与82例无直肠病变者(对照组)的ADC值,并在观察组中比较磁共振成像(MRI)和DWI对直肠腺癌T分期诊断的准确性.结果 观察组ADC平均值为(0.89±0.12)×10-3mm2/s,低于对照组ADC平均值(1.45±0.15)×10-3mm2/s,差异有统计学意义(P﹤0.05).对于直肠腺癌的诊断,ADC的最佳分界值为1.26×10-3mm2/s,敏感度为96.1%,特异度为97.5%;低分化、中分化和高分化直肠腺癌的ADC值分别为(0.80±0.10)×10-3mm2/s、(0.95±0.11)×10-3mm2/s和(1.23±0.18)×10-3mm2/s,不同分化程度的ADC值比较,差异有统计学意义(P﹤0.05).对于直肠腺癌,MRI分期诊断的准确性为74.39%,DWI分期诊断的准确性为86.59%,两者比较,差异有统计学意义(P﹤0.05).结论 直肠腺癌的不同分化程度与ADC值相关,DWI可以增加直肠腺癌术前分期诊断的准确率.     

ADC值测量在颅脑DWI高信号肿瘤诊断中的价值

目的:探讨ADC值测量对颅脑DWI高信号肿瘤的诊断价值.方法:对46例DWI高信号肿瘤分类,并测量其ADC值.结果:胶质瘤、转移瘤、脑膜瘤、淋巴瘤ADC值分别为(0.90±0.16)×10-3mm2/s、(0.75±0.21)×10-3mm2/s、(0.86±0.11)×10-3mm2/s、(0.91±0.16)×10-3mm2/s,各肿瘤之间的ADC值无显著性差异(P＞0.05),低级别胶质瘤与高级别胶质瘤之间ADC值有统计学差异(P＜0.05).结论:对DWI高信号肿瘤ADC值测量可以提供脑肿瘤的组织成分信息,ADC值可预测胶质瘤级别.     

磁共振弥散加权成像对脊柱转移瘤放疗疗效的评估

[目的]探讨磁共振弥散加权成像（DWI）对脊柱转移瘤放疗疗效的评估价值。[方法]收集30例脊柱转移瘤患者放疗前、后2个月的磁共振图像,所有患者均进行常规MRI及DWI序列。比较常规MRI序列与DWI序列对病灶的检出率。同时对照分析30例患者放疗前、后的DWI信号、ADC值。[结果]放疗前常规MRI扫描共发现病灶48个,累及42个椎体。DWI序列发现病灶56个,累及48个椎体。放疗结束后2个月复查MRI,SET1WI上脊柱转移瘤信号不变或略有下降。FSET2WI上20例信号轻度下降,10例不变。而在临床症状有改善的26例病例中,相对于放疗前,转移瘤DWI信号明显降低。在b=650s／mm2的DWI中,脊柱转移瘤放疗前表观扩散系数（ADC）值为（0．72±0．21）×10-3mm2／s,放疗后ADC值升高到（1．32±0．22）×10-3mm2／s;相邻正常椎体骨髓的ADC值较转移瘤低,且放疗前后没有变化。f结论]DWI序列既可以提高MRI对脊柱转移瘤的检出率,也可以用于监测和评估脊柱转移瘤的放疗疗效。     

Quantitative probabilistic functional diffusion mapping in newly diagnosed glioblastoma treated with radiochemotherapy

Background

Functional diffusion mapping (fDM) is a cancer imaging technique that uses voxel-wise changes in apparent diffusion coefficients (ADC) to evaluate response to treatment. Despite promising initial results, uncertainty in image registration remains the largest barrier to widespread clinical application. The current study introduces a probabilistic approach to fDM quantification to overcome some of these limitations.

Methods

A total of 143 patients with newly diagnosed glioblastoma who were undergoing standard radiochemotherapy were enrolled in this retrospective study. Traditional and probabilistic fDMs were calculated using ADC maps acquired before and after therapy. Probabilistic fDMs were calculated by applying random, finite translational, and rotational perturbations to both pre-and posttherapy ADC maps, then repeating calculation of fDMs reflecting changes after treatment, resulting in probabilistic fDMs showing the voxel-wise probability of fDM classification. Probabilistic fDMs were then compared with traditional fDMs in their ability to predict progression-free survival (PFS) and overall survival (OS).

Results

Probabilistic fDMs applied to patients with newly diagnosed glioblastoma treated with radiochemotherapy demonstrated shortened PFS and OS among patients with a large volume of tumor with decreasing ADC evaluated at the posttreatment time with respect to the baseline scans. Alternatively, patients with a large volume of tumor with increasing ADC evaluated at the posttreatment time with respect to baseline scans were more likely to progress later and live longer. Probabilistic fDMs performed better than traditional fDMs at predicting 12-month PFS and 24-month OS with use of receiver-operator characteristic analysis. Univariate log-rank analysis on Kaplan–Meier data also revealed that probabilistic fDMs could better separate patients on the basis of PFS and OS, compared with traditional fDMs.

Conclusions

Results suggest that probabilistic fDMs are a more predictive biomarker in terms of 12-month PFS and 24-month OS in newly diagnosed glioblastoma, compared with traditional fDM analysis.     

肺癌3.0T磁共振表观扩散系数变化与病理类型的相关性

目的:研究不同病理类型肺癌磁共振表观扩散系数差异,并采取高b值评价肿瘤内部特征.方法:经临床手术病理证实的72例肺癌患者,行MRI T1 WI、T2 WI、T2压脂和DWI扫描(b值为0、500、1 000、2 000s/mm2);对不同b值所算出的ADC图上的病灶进行测量,利用方差分析比较其差异.对b值为2000的ADC值进行分析,比较b值为1 000的ADC值,以t检验和方差分析进行比较.结果:本组70例肺癌显示高信号,2例小细胞癌未显示明显高信号,随b值增加,DWI信号强度增大.不同b值,平均ADC值均随b值增加而逐渐变小,差异有统计学意义.不同类型肺癌ADC值有差异.结论:不同病理组织类型的肺癌其ADC值不同,b值为1 000s/mm2和高b值(b=2 000s/mm2)时,平均ADC值均有价值,对于分化良好的腺癌,高b值(b=2 000s/mm2)时鉴别诊断更有价值,并且对良恶性肿瘤鉴别及恶性程度高低有一定价值.     

全身扩散加权成像在恶性淋巴瘤诊断与疗效评估中的价值

Objective  

The aim was to evaluate the role of whole body diffusion weighted imaging (WB-DWI) of magnetic resonance in the diagnosis and efficacy evaluation of malignant lymphoma.     

瘤周水肿区ADC值在恶性胶质瘤及脑转移瘤鉴别诊断中的价值

[目的]探讨MR扩散加权成像（DWI）瘤周水肿区表观扩散系数（ADC）值在恶性胶质瘤及脑转移瘤鉴别诊断中的价值。[方法]32例恶性胶质瘤（≥Ⅲ级）和24例脑转移瘤患者进行常规MRI扫描和DWI检查。分析比较两者肿瘤的边缘特征及瘤周近、远侧水肿带的表观扩散系数（ADC）和相对表观扩散系数（rADC）。[结果]恶性胶质瘤近瘤水肿带的ADC值及rADC值分别为1.44×10-3±0.15×10-3mm2/s和2.01±0.24,远瘤水肿带分别为1.81×10-3±0.21×10-3mm2/s和2.49±0.33。脑转移瘤近瘤水肿带的ADC值及rADC值分别为1.70×10-3±0.22×10-3mm2/s和2.43±0.44,远瘤水肿带分别为1.81×10-3±0.18×10-3mm2/s和2.54±0.41。恶性胶质瘤和脑转移瘤近瘤水肿带的ADC值和rADC值之间的差异有统计学意义（P〈0.01）,而远瘤水肿带间的差异无统计学意义（P〉0.05）;恶性胶质瘤近、远瘤水肿带的ADC值和rADC值之间的差异有统计学意义（P〈0.01）;脑转移瘤近、远瘤水肿带的ADC值和rADC值之间的差异无统计学意义（P〉0.05）。[结论]在DWI上,恶性胶质瘤和脑转移瘤的边缘特征以及瘤周近、远侧水肿带的ADC值及rADC值的差异对两者的鉴别诊断具有重要价值。     

Studium der Diffusion im Knorpel mit der „PFG” (pulsed-field-gradient)-NMR-Technik

Since cartilage does not contain any blood vessels, diffusion is the most important transport mechanism for its supply. Although several methods are available for the measurement of diffusion, this study focuses exclusively on NMR methods. Besides the, classic“ water diffusion, the diffusion behaviour of ions and polymers in cartilage is also described. In all cases, and at short observation times, diffusion is mostly determined by the water content of the sample. However, the variation of the observation time allows to obtain information also on the internal structure of cartilage. In addition, it is discussed to which extent the individual techniques allow conclusions with respect to degenerative joint diseases, and under which in vivo conditions they can be applied.     

磁共振弥散加权成像在评估子宫颈癌放化疗效果中的应用

目的 探讨采用磁共振弥散加权成像（DWI）对子宫颈癌放化疗效果进行评价的可行性.方法 收集子宫颈正常志愿者13名,子宫颈癌患者32例,年龄29～72岁,平均45.75岁.32例子宫颈癌患者于放疗前及放化疗后1～3个月内行磁共振成像（MRI）常规扫描和DWI扫描,取b值分别为（0,300）s/mm2及（0,600）s/mm2.在轴位DWI图上分别测量正常子宫颈表面扩散系数（ADC）值及子宫颈癌患者子宫颈肿块ADC值,对放化疗后子宫颈病变区进行ADC值的测量,并进行比较.结果 当b=（0,300）s/mm2时,正常子宫颈ADC值平均为（1.72±0.31）×10^-3 mm2/s,放疗前子宫颈癌为（1.10±0.24）×10^-3 mm2/s,放化疗后的子宫颈病变为（1.61±0.23）×10^-3 mm2/s;当b=（0,600）s/mm2时,正常子宫颈ADC值平均为（1.46±0.25）×10^-3 mm2/s,放疗前子宫颈癌为（0.89±0.21）×10^-3 mm2/s,放化疗后的子宫颈病变为（1.54±0.18）× 10^-3 mm2/s;b=300 s/mm2的ADC值均高于b=600 s/mm2时.子宫颈癌组ADC值低于正常子宫颈组,放化疗后病变子宫颈的ADC值明显高于治疗前,差异均有统计学意义（均P＜0.05）.但同组不同b值的ADC值差异均无统计学意义（均P＞ 0.05）.结论 DWI与ADC值的联合可以更为客观、准确地分析病变,有助于评价放化疗效果.     

Graded functional diffusion map-defined characteristics of apparent diffusion coefficients predict overall survival in recurrent glioblastoma treated with bevacizumab

Diffusion imaging has shown promise as a predictive and prognostic biomarker in glioma. We assessed the ability of graded functional diffusion maps (fDMs) and apparent diffusion coefficient (ADC) characteristics to predict overall survival (OS) in recurrent glioblastoma multiforme (GBM) patients treated with bevacizumab. Seventy-seven patients with recurrent GBMs were retrospectively examined. MRI scans were obtained before and approximately 6 weeks after treatment with bevacizumab. Graded fDMs were created by registering datasets to each patient's pretreatment scan and then performing voxel-wise subtraction between post- and pretreatment ADC maps. Voxels were categorized according to the degree of change in ADC within pretreatment fluid-attenuated inversion recovery (FLAIR) and contrast-enhancing regions of interest (ROIs). We found that the volume of tissue showing decreased ADC within both FLAIR and contrast-enhancing regions stratified OS (log-rank, P < .05). fDMs applied to contrast-enhancing ROIs more accurately predicted OS compared with fDMs applied to FLAIR ROIs. Graded fDMs (showing voxels with decreased ADC between 0.25 and 0.4 μm(2)/ms) were more predictive of OS than traditional (single threshold) fDMs, and the predictive ability of graded fDMs could be enhanced even further by adding the ADC characteristics from the fDM-classified voxels to the analysis (log-rank, P < .001). These results demonstrate that spatially resolved diffusion-based tumor metrics are a powerful imaging biomarker of survival in patients with recurrent GBM treated with bevacizumab.     

DWI在孤立型肺结节中的应用

Objective  

The aim of our study was to investigate the value of Diffusion-weighted MR imaging (DWI) for evaluating differential diagnosis of pulmonary isolated lesions.     

MR扩散加权成像对食管癌患者同步放化疗疗效的预测价值

目的:探讨MR扩散加权成像对食管癌患者同步放化疗疗效的预测价值.方法:选取2012年6月-2014年5月在本院就诊的103例食管癌病人作为研究对象,所有患者于治疗前行磁共振的扩散加权成像(diffusion weighted imaging,DWI)检查,测量肿瘤平均、最低ADC值和最高ADC值;并于治疗前和治疗中第2、4、6周及第8周行MR检查,根据实体瘤的疗效评价标准,将患者进行疗效分组,分为治疗有效组和无效组,比较两组的各项指标,采用受试者工作特征曲线(receiver operating characteristic curve,ROC)分析治疗前ADC值预测疗效的诊断效能.结果:103例食管癌患者吞咽困难症状于2周后逐渐缓解,治疗8周后得到明显改善,癌灶较治疗前明显缩小;DWI图显示在治疗8周后患者的瘤体在逐渐缩小,病灶信号逐渐降低,与同步放化疗前相比差异具有统计学意义(P＜0.05);化疗后有效组与无效组病灶厚度、病灶长径、化疗后平均ADC、最低ADC、最高ADC值差异均具有统计学意义(均P＜0.05);ROC显示以肿瘤治疗前平均ADC值预测食管癌同步放化疗疗效的灵敏度、特异度、阳性似然比、阴性似然比分别是80.0％、69.7％、2.64、0.29;最低ADC值预测食管癌同步放化疗疗效的灵敏度、特异度、阳性似然比、阴性似然比分别是75.7％、78.8％、3.57、0.31;最高ADC值ROC曲线下面积0.759,临界点取2.20× 10-3mm2/s,其预测食管癌同步放化疗疗效的灵敏度、特异度、阳性似然比、阴性似然比分别是94.3％、48.5％、1.83、0.12.结论:MR扩散加权成像能够较好的预测食管癌患者同步放化疗的治疗效果,有望为食管癌个体化治疗提供依据.     

Évolution de la double diffusion au CO et au NO au cours de la radiothérapie pulmonaire pour cancer bronchique : présentation du protocole de l’étude prospective Conort

Thoracic radiotherapy is a usual treatment for lung cancer. Early-stages may be treated in stereotactic mode while locally advanced stages are usually treated with conventional radiotherapy mode. Pulmonary function tests show that thoracic irradiation has no impact on lung volume such as forced expiratory volume in one second (FEV1) or forced vital capacity (FCV). However, some studies found that CO (carbon monoxide) diffusing capacity (TLCO) may be altered under thoracic radiotherapy. DLCO alteration is usually symptomatic of either a lesion in the alveolar membrane or a pulmonary capillary alteration. Pulmonary diffusion may be also appreciated by the NO (azote monoxide) diffusion capacity. Moreover, using a double measurement of NO and CO diffusing capacities permit to assess which lung compartment (capillary or membrane) is affected. CONORT is an observational prospective monocentric study, aiming to assess the CO and NO diffusing capacity (as well as other pulmonary function tests) during thoracic radiotherapy. Inclusion criteria are patients with lung cancer, treated by thoracic radiotherapy (conformational or stereotactic), who signed consent. Pulmonary function tests are performed before, during, at the end and six weeks and six months after thoracic irradiation. To estimate a difference of 15% in diffusing capacity test, we have to include 112 patients with a 90% power and a 5% alpha risk. Four months after beginning, 36 patients were included. Preliminary data will be presented at the SFRO meeting.     

Small islet cell tumour in the pancreas: diagnostic value of diffusion-weighted MRI

We present a case of a small islet cell tumour that was clearly depicted on diffusion-weighted imaging using a free breathing approach and discuss the diagnostic value of this sequence.     

A Feasibility Study Evaluating the Functional Diffusion Map as a Predictive Imaging Biomarker for Detection of Treatment Response in a Patient with Metastatic Prostate Cancer to the Bone

Prostate cancer (PCa) is the most commonly diagnosed cancer in American men with a subset inevitably presenting with metastatic disease to the bone. A well-recognized limitation in evaluating new treatments for metastatic PCa is the inability to use imaging to objectively assess response therapy. In this study, we evaluated the feasibility of clinically translating the functional diffusion map (fDM) imaging biomarker for quantifying the spatiotemporal effects of bone tumor response in a patient treated for metastatic PCa with bone metastases. A patient beginning therapy was scanned using MRI before treatment and again at 2 and 8 weeks post-treatment initiation to quantify changes in tumor diffusion values. Three metastatic lesions were identified for fDM analysis, all of which all demonstrated an early increase in diffusion values at 2 weeks, which increased further at 8 weeks post-treatment initiation. This finding correlated with a decrease in the patient''s prostate-specific antigen (PSA) levels suggestive of patient response. CT, bone scans, and anatomic MRI images obtained posttreatment were found to be uninformative for the assessment of treatment effectiveness. This study presents the feasibility of fDM-measurements in osseous lesions over time and shows that changes in fDM values were consistent with therapeutic response. Thus, the fDM imaging biomarker may provide a quantifiable therapeutic endpoint to assess response in patients with metastatic bone cancer.     

Correlation of diffusion MRI with the Ki-67 index in non-small cell lung cancer

Background

The primary objective of the study was to evaluate the association between the minimum apparent diffusion coefficient (ADC_min) and Ki-67, an index for cellular proliferation, in non-small cell lung cancers. Also, we aimed to assess whether ADC_min values differ between tumour subtypes and tissue sampling method.

Methods

The patients who had diffusion weighted magnetic resonance imaging (DW-MRI) were enrolled retrospectively. The correlation between ADC_min and the Ki-67 index was evaluated.

Results

Ninety three patients, with a mean age 65 ± 11 years, with histopathologically proven adenocarcinoma and squamous cell carcinoma of the lungs and had technically successful DW-MRI were included in the study. The numbers of tumour subtypes were 47 for adenocarcinoma and 46 for squamous cell carcinoma. There was a good negative correlation between ADC_min values and the Ki-67 proliferation index (r = −0.837, p < 0.001). The mean ADC_min value was higher and the mean Ki-67 index was lower in adenocarcinomas compared to squamous cell carcinoma (p < 0.0001). There was no statistical difference between tissue sampling methods.

Conclusions

Because ADC_min shows a good but negative correlation with Ki-67 index, it provides an opportunity to evaluate tumours and their aggressiveness and may be helpful in the differentiation of subtypes non-invasively.     

弥散张量成像鉴别良性脑膜瘤亚型及相关研究

目的：探讨弥散张量成像（DTI）鉴别良性脑膜瘤亚型及其在手术中的应用价值。方法：57例经手术病理证实的良性脑膜瘤患者,术前均行头部MRI常规平扫及增强扫描,并加做DTI检查。结果：纤维母细胞型脑膜瘤部分各向异性（FA）值明显高于其它亚型脑膜瘤,差别有显著性意义;表观弥散系数（ADC）值各亚型间有差异,但无显著性意义。弥散张量成像能直观地显示肿瘤与重要神经纤维束的关系,纤维束受累情况与临床症状具有良好相关性;结论：FA值可以作为鉴别纤维母细胞型脑膜瘤与其它良性亚型脑膜瘤的重要参数之一,从中可获得术前关于其软硬度的信息。弥散张量成像对指导脑肿瘤手术及判断预后具有重要临床价值。     

食管癌渗疗71例近期疗效观察

采用食管渗疗器,治疗中,晚期食管癌71例。用高浓度5-Fu,食管腔内局部渗透给药。CR PR=66.2％,为Selawry报告静脉给药疗效的9.45倍。平均生存期9个月以上。渗疗前后检查对比,未见毒副反应。操作简单,适应症广,为治疗中、晚期食管癌创一新路。