MR permeability mapping in vivo: characteristics of various tissues and usefulness as predictive index for treatment

我们开发了一种频率选择性脂肪饱和双回波2DFLASH序列，可以在一次TR中获得T1加权和T2*加权的梯度回波图像。设备为西门子Magnetome Vision(西门子，1.5T)，所用参数为：TR/TE1和TE2/FA=~27/2.3和20/45度，矩阵256×64，NEX=1。经上肢浅静脉系统以2CC/s的速度静脉注射Gd-DTPA(0.1 mmol/kg)后，进行单层动态研究。扫描进行了大约2分钟，检查过程中要求患者进行浅而稳定的呼吸。我们将重点放在盆腔疾病过程中，因为他们几乎没有呼吸运动伪影，而且病理证据在我们的设备中相对容易获得。我们开发了利用TE1和TE2图像计算纯T1(R1)和纯T2*(R2*)图像的软件。我们还开发了一个软件来帮助创建预对比度T1值映射，这是强制…更多以计算R1和R2*映像。分析静脉注射Gd后r1和r2*图像的时序变化。这两个图像被认为分别代表了血管和通透性以及血管单独的总和效应，这两个图像的结合可能有助于对疾病过程的新理解。然而，由于没有足够的理论模型来定量计算和评估这两个指标，我们这次进行了定性评估。我们检查了几种盆腔内疾病，包括24例子宫肌瘤、5例宫颈癌、4例子宫内膜癌、4例卵巢癌等。将R1和R2*图像的动态曲线分为6类(I：平台，II：峰值，III：峰值和平台，IV：逐渐增加，V：平坦，VI：未分类)。正常宫体、阴道-尿路复合体、肌瘤在RL和R2*图像上分别为I类和V类。正常骨髓在R1和R2*图像上均为I类。子宫腺肌病，一些宫颈癌在R2*图像上表现为II或III类。仔细分析R1和R2*图像可以揭示不同疾病过程中新生血管和通透性的变化。还需要进一步的研究，以澄清R1和R2*图像在更大人群中的有用性，并开发能够对这两个指数进行定量分析的软件。较少

We have developed a frequency-selective fat saturated dual-echo 2DFLASH sequence to obtain T1weighted and T2* weighted gradient-echo images at one TR. The equipment used was Magnetome Vision (Siemens, 1.5T), and the parameters used were as follows; TR/TE1 ＆ TE2/FA=〜27/2.3 ＆ 20 /45 degrees, matrix 256x64, NEX=1. Single slice dynamic study was performed after intravenous bolus injection of Gd-DTPA (0.1mmol/kg) at a rate of 2cc/sec via superficial venous system of the upper extremities. Scanning was performed for approximately 2 minutes and the patients were asked to breathe shallowly and consistently during the examination.We focused on pelvic disease processes because they had little respiratory motion artifacts and pathologic evidence was relatively easily obtained in our instiute. We developed software to calculate pure T1 (R1) and pure T2* (R2*) images utilizing.the TE1 ＆ TE2 images. We also developed a software to facilitate to create precontrast T1-value mapping which is mandatory … More to calculate R1 ＆ R2* images. Sequential changes of R1 and R2* images were analyzed after Gd intravenous injection. These two were considered to represent summation effect of vascularity and permeability and vascularity alone, respectively, and combination of these two images may contribute to novel understanding of disease processes. However, because adequate theoretical model was not available to calculate and evaluate these two indices quantitatively, we carried out qualitative evaluation this time.We examined several intrapelvic diseases including 24 uterine myomas, 5 cervical carcinomas, 4 endometrial carcinomas, 4 ovarian carcinomas, and so on. Patterns of dynamic curves of R1 and R2* images were subclassified into 6 categories (I: plateau, II: peak, III: peak ＆ plateau, IV: gradual increase, V: flat, VI: unclassified). Normal uterine body, vagino-urethral complex, myomas showed categories I and V on Rl and R2* images, respectively. Normal bone marrow showed category I both on R1 and R2* images. Adenomyosis of the uterus, some of the cervical cancers showed categories II or III on R2* images.Meticulous analysis of R1 and R2* images may reveal neovascularity and permeability change in various disease processes. Further investigation is needed to clarify the usefulness of R1 and R2* images in larger population and also to develop soft ware which enables quantitative analysis of these two indices. Less