【作者】 张洪涛；

【导师】 李功杰；

【作者基本信息】 中国人民解放军军事医学科学院 ， 肿瘤学， 2010， 硕士

【摘要】 背景与目的:恶性肿瘤患者需要覆盖全身的影像检查方法来确定肿瘤的TNM分期,以指导临床医生进行治疗、预后判断及疗效评价。可以一次覆盖全身的检查方法越来越受到临床的重视。目前临床常用的全身性影像检查手段包括CT、SPECT、MRI、PET-CT检查等。CT、SPECT对人体的放射剂量太大,不适宜用于短期内检测、复查手段。PET-CT是近年来逐渐发展形成的一种重要的全身检查方法,但其价格昂贵,不能被大多数患者接受。MRI具有良好的软组织对比,适于进行肿瘤显像,但由于检查时间过长及使用线圈的限制,全身MRI检查需多次扫描才能完成。近几年,随着MRI软件及硬件的发展,快速成像序列及并行采集技术等的引进,使MRI单次全身扫描成为可能。全身弥散加权成像技术多采用STIR- DWI- EPI序列,根据组织内部水分子弥散运动的改变判断其内组织结构的变化。由于恶性肿瘤最常见的全身转移部位是淋巴结、肝脏及骨骼,本文的研究目的在于探讨全身弥散加权成像在恶性肿瘤淋巴结、肝脏及骨骼转移方面的临床应用价值,以及ADC值在鉴别转移病灶与非转移病灶方面的应用价值。内容:以我院2009-05~2009-12期间收集的58例全身弥散加权成像为研究对象,其中健康志愿者26例,恶性肿瘤患者32例(恶性肿瘤患者均有病理结果)。32例恶性肿瘤患者临床通过病理活检证实部分淋巴结、肝转移;本组病人全都做过PET-CT检查;32例恶性肿瘤患者全部在我院进行放化疗,多次进行CT、MRI检查(时间间隔最长为一个月)观察病变大小是否有变化。临床通过综合分析以上方法确定确切的淋巴结转移、肝转移及骨转移。把临床确诊的淋巴结转移、肝脏转移及骨骼转移病灶与WB-DWI发现的淋巴结转移、肝脏转移及骨骼转移病灶进行对比分析。方法:采用GE HD1.5T超导磁共振扫描仪,利用体线圈进行扫描,信号采集使用磁体内置BODY线圈,应用STIR-DWI-EPI序列,在自由呼吸状态下进行全身弥散加权成像,扫描范围是自头扫到膝关节附近,分四段进行扫描,每段之间有三个层面的重叠,平卧、足先进,激光标志线定位于眉间。然后把原始图像在工作站上(AW4.3)进行后处理,使用Add/Sub软件对4段原始图像进行段与段之间的无缝叠加,然后利用3D-MIP重建及黑白反转技术,三维的显示病变,结合横断面原始图像,利用Functool软件对可疑病变进行定位并测量ADC值,根据信号特点及ADC值确定淋巴结转移、肝脏转移及骨骼转移的部位及数目。观察26例健康志愿者WB-DWI上正常淋巴结的显示情况并测量ADC值,并测量一定数目的正常骨骼及肌肝组织的ADC值。观察32例恶性肿瘤患者WB-DWI上淋巴结转移、肝转移及骨转移的显示情况,并测量转移病灶的ADC值。然后把WB-DWI上显示淋巴结转移、肝转移及骨转移与临床确诊的实际淋巴结转移、骨骼转移及肝转移进行对比分析,得出WB-DWI诊断淋巴结转移、肝脏转移及骨骼转移的真阳性数、假阳性数、假阴性数及准确率。我们把淋巴结转移部位分为颈部、两侧腋窝、锁骨上下区、纵膈、肺门、腹腔、腹膜后、盆腔(包括腹股沟区)八个区域,在根据淋巴结短径的大小分为(短径:≤1.0cm、1.0<~<1.5cm、1.5≤~<2.0cm、≥2.0cm)四组。分别计算淋巴结转移在不同短径组、不同部位的准确率。把骨骼系统分为颅骨、肋骨、胸锁骨、脊柱、骨盆、四肢骨六个区域,计算骨骼转移在各个区域的真阳性数、假阳性数、假阴性数及准确率。最后把淋巴结转移、肝转移、骨转移与正常淋巴结、肝实质、骨的ADC值进行比较,并把不同部位、不同短径组的转移淋巴结与正常淋巴结、不同区域的骨转移与正常骨组织的ADC值进行比较。应用SAS 9.13统计软件采用成组设计定量资料的t检验、单因素K水平定量资料的方差分析进行统计分析。结果:背景抑制的WB-DWI经MIP重建及黑白反转技术,病变周围组织信号被抑制,转移病灶均清晰显示。WB-DWI发现淋巴结、肝脏及骨骼转移病灶的能力能够满足临床的要求,淋巴结转移、肝转移、骨转移的准确率分别为94.4%、90.5%、85.6%。WB-DWI诊断短径大于或等于1.5cm转移淋巴结的准确率为100%,诊断短径小于或等于1.0cm的转移淋巴结中腹膜后区域的准确率最低(50%),诊断短径大于1.0cm且小于1.5cm的转移淋巴结中盆腔区域的准确率最低(33.3%)。WB-DWI诊断六个区域的骨转移中,诊断四肢骨转移的准确率最低(66.7%)。WB-DWI在b=800s/mm2的图像中,淋巴结转移、肝转移、骨转移与正常淋巴结、肝实质、骨间的ADC值差异具有统计学意义(P<0.05),不同短径组间转移淋巴结的ADC值无统计学意义(P>0.05)。结论:磁共振全身弥散加权成像在显示恶性肿瘤淋巴结、肝脏、骨骼转移病灶方面具有一定优势,准确率都非常高,能够满足临床的要求,为临床确定肿瘤的TNM分期提供新的影像检查手段。尤其诊断全身淋巴结转移具有明显的优势。此外ADC值作为一个定量数值,能够为转移病灶的确定提供重要的临床参考价值。更多还原

【Abstract】 Background and objective: Patients of malignant tumors need inspection methods of covering the whole body to determine TNM stage of the tumors for clinical treatment, prognosis and evaluation of treatment. Methods of covering the whole body are more and more important. Now they are commonly used in systemic clinical assessment, including CT,SPECT,MRI,PET-CT,and so on. CT and SPECT are harmful to the human body, and they are not suitable for detection of short-term and means of review. Recently, PET-CT is an important way of covering the whole body, but it is very expensive and not popular. MRI has excellent soft tissue contrast and is suitable for tumor imaging. But time of inspection is too long and restriction of coils, so MRI scan of whole body need multiple scans. In recent years, with the development of MRI software and hardware, fast imaging sequences and parallel acquisition techniques develop and MRI scan of whole body is possible. WB-DWI imaging technique uses STIR-DWI-EPI sequence and determine the change of organizational structure according to diffusion of water molecules within the organization. Because the most common systemic metastases are lymph nodes, liver and bones, purpose of this paper is to explore the clinical value in the lymph-node ,live and bones metastasis of malignant tumors in the whole body diffusion weighted imaging and ADC value in the identification between metastatic lesions and benign lesions.Content: Fifty-eight patients with the whole body diffusion weighted imaging are collected from 2009-05 to 2009-12 in our hospital for the study, including 26 volunteers and 32 patients with malignant tumors (all have pathological findings).Lymph node metastasis, liver metastasis and bone metastasis of thirty-two cases are diagnosed by biopsy, PET-CT (all cases have PET-CT examination) or more CT, MRI being followed up for changes in lesions size (the time interval of one month).The clinical diagnosis of lymph node metastasis, liver metastasis and bone metastasis are contrasted with lymph node metastasis, liver metastasis and bone metastasis in WB-DWI imaging.Methods: GE HD1.5T are used, body coil is used, Signal acquisition uses the built-in magnet body coil, STIR-DWI-EPI sequence is used and the whole body diffusion weighted imaging is scanned in the free breathing condition. Scan range is from the head to the knee, Scanned four times, there are overlaps of three levels between each section, supine, feet first, laser-line is located in the glabellum. Then the original images are processed on the workstation (AW4.3), the Add / Sub software is used and sections are seamlessly superimposed. The 3D-MIP reconstruction and black and white reversal technology are used. Lesions are displayed by three-dimension, the original cross-sectional images are used, suspicious lesions are located and measured the ADC value by Functool software. According to ADC value and the signal characteristics, the position and number of lymph node metastasis, liver metastasis and bone metastasis are determined. Normal lymph nodes of twenty-six healthy volunteers are investigated on the WB-DWI imaging and the ADC value of lymph nodes are measured, then ADC value of a certain number of normal bone and liver tissue are measured.Lymph node metastasis, liver metastasis and bone metastasis of 32 cases of malignant tumors are observed on WB-DWI imaging, and the ADC values of metastatic lesions measured. Then lymph node metastasis, liver metastasis and bone metastasis on WB-DWI imaging are compared with the actual clinical diagnosis of lymph node metastasis, bone metastasis and liver metastasis. The number of true positive, false positive , false negative and accuracy rate of lymph node metastasis, bone metastasis and liver metastasis are computed. Locations of lymph node metastasis are divided into eight regions, including cervical part, both sides of the axillary fossa, clavicular region, mediastinum, hilum of lung, peritoneal cavity, retroperitoneal area, cavitas pelvis (including the groin area). Lymph node metastasis are divided into four groups according to short diameter of lymph nodes(short diameter:≤1.0cm、1.0<~<1.5cm、1.5≤~<2.0cm、≥2.0cm). Accuracy rate is calculated in various regions and different shirt diameter groups of lymph node metastasis. The skeletal system is divided into the skull, ribs, sternoclavicular ,spine, pelvis, limbs. Accuracy rate in various regions of bone metastasis are calculated. Finally the ADC values of lymph node metastasis, liver metastasis and bone metastasis are compared with the ADC value of normal lymph nodes, liver and bone, then quantitative data group t-test design and single factor analysis of variance are applied through SAS 9.13 statistical software.Results: In the WB-DWI imaging, the signal of surrounding tissues of the lesions is inhibited and metastatic lesions are clearly displayed. The ability to identify metastasis can satisfy clinical demand. Accuracy rate of lymph node metastasis, liver metastasis, bone metastasis reaches to 94.4%、90.5%、85.6%.The accuracy rate of lymph node metastasis (short diamete≥1.5cm) reach to 100% on the WB-DWI imaging. The lowest accuracy rate of lymph node metastasis (short diameter≤1.0cm) reaches to 50% on the retroperitoneal region and the lowest accuracy rate of lymph node metastasis (1.0<short diameter <1.5cm) reaches to 33.3% on the pelvic region. The lowest accuracy rate of bone metastasis on sternoclavicular of six regions reaches to 66.7% on the WB-DWI imaging. In the WB-DWI imaging of b = 800s/mm2,the differences of the ADC value between metastatic lymph nodes and normal lymph nodes, metastasis of liver and normal liver, metastasis of bones and normal bones are statistically significant(P<0.05). The differences of the ADC value between metastatic lymph nodes in different short diameter groups are not statistically significant (P>0.05).Conclusions: The whole body diffusion weighted imaging in the display of lymph node metastasis, liver metastasis and bone metastasis has some advantages. The accuracy rate is very high and the ability to identify metastasis can satisfy clinical demand. It provides a new means of image for the clinical TNM staging of the tumor. In particular, diagnosis of systemic lymph node metastasis has obvious advantage. In addition, the ADC value is quantitative value and it provides great value in the determination of tumor metastasis.更多还原