CT与MRI的对比

 

翻译:贺芮 审核:Frank

英文原文:http://gistsupport.medshelf.org/CT_VS_MRI

在我身患胃肠间质瘤的这九年里,我和在 Fox Chase 癌症中心的Von博士聊了很多次。她觉得对他来说看CT比核磁共振成像更容易一些。同时她认为CT对检测腹部的胃肠间质瘤更有效率,但是她也承认一个训练良好的放射线医生很可能可以精确地追踪GIST。我认为她自己比较喜欢看扫描的图像,而且她看CT比MRI的更快。我也认为不是所有的MRI机器制作精良(不确定)。

我想如果有机会,更多的人将会尝试MRI,因为最近有一种说法是关于辐射照量的,这样我们的生命将可以延续更长的时间。也许有一天科技将会足够发达从而减少辐射的影响。

Haesun博士(安德森癌症中心的检测GIST的放射科专家)在最近的论文中提到了关于MRI的信息。以下是他的原文:

“在评估肝脏转移和直肠间质瘤方面,上层软组织造影剂以及多平面成像的MRI比造影强化CT的效果更好。然而,在GIST的检测当中,MRI并非主要的显像形式,因为他在检测腹膜肿瘤的过程中通常灵敏度有限。但是通过精心设计的且专业的MRI的分析(薄切片,如 5mm,饱和脂肪的T1级别成像 < 5 mm, fat-saturated T1-weighed images),可以很好的观测到大部分病人腹腔成像情况。”

“MRI中,GIST的迹象一般定义比较清楚。肿瘤的实质部分T1序列形成低-中信号,T2序列形成高信号。 在CT中,在使用静脉性造影剂之后肿瘤增强。静脉造影剂有助于描述含实质成分的肿块和未被增强的坏死区域。内出血的状况,根据不同的年龄,呈现出在MRI中在T1和T2序列上从高到低不同的信号强度变化。”

“MRI可以用来区分CT图像上的可疑的高密度瘤内肿块与出血。动态对比增强磁共振成像可用于评估肿瘤活动性和量化血管生成的状态。然而,据作者所知,并没有公开发表的系列研究评估这种成像技术在治疗GIST方面的价值。”

所以核磁共振成像的一个缺点是在检测腹膜时更加困难,但是Choi博士似乎认为科技可以改变这一点。

下面是一些关于使用MRI检测GIST和其他腹膜肿瘤的总结。对于肝脏检测MRI明显优于CT。它唯一的不足是对于肠系膜和腹膜的检测。所以这篇文献强调了这一点。如果你有肾脏功能受损,或者你对碘过敏,或者你想减少辐射,那么你可以跟你的放射科医生和肿瘤医生讨论MRI的使用。

这是Levy Shaw & Sobin的论文中一段(第一文摘如下):

“在检测腹膜腔时,尽管磁共振成像(MRI)不如CT成像那样广泛使用,,其优越的对比分辨率使得它在评价腹膜腔时非常有用。静脉注射钆后的腹膜种植转移扩散缓慢,因此最好在获得注射后5 - 10分钟显示图像。因为正常腹膜增强程度与肝脏中的增强程度相似,所以当腹膜增强程度大于肝脏时,或者出现增厚和结节状态时,应当怀疑为异常增强 (15)。常规CT在检测腹膜扩散的敏感性低(60% - -79%)(12、16)。在最近的研究中,应用了螺旋CT扫描仪,CT显示改善了总体敏感性(85% - -93%),但检测植入小于1厘米的肿瘤时,其敏感性(25% - -50%)仍然很低  (17)。相比之下,MRI成像已被证明比CT有更好的灵敏度(85% - -90%)当被检测肿瘤结节小于1厘米时。和整体灵敏度腹膜肿瘤结节的84%(18)。

《射线照相》2009 Mar-Apr;29(2):347-73.

转移肿瘤和腹腔肿瘤样病变:成像特征与病理的相关性

characterized by recurrent and recalcitrant voluminous mucinous ascites due to surface growth on the peritoneum without significant invasion of underlying tissues. Carcinomas from elsewhere in the body, as well as lymphomas and sarcomas, may also produce diffuse peritoneal metastasis. Granulomatous peritonitis is the consequence of disseminated infection such as tuberculosis or histoplasmosis, foreign materials, or rupture of a tumor or hollow viscus. Finally, a group of benign miscellaneous conditions that range from common disorders such as endometriosis and splenosis to very rare conditions such as gliomatosis peritonei and melanosis may also affect the peritoneum diffusely. Secondary tumors and tumorlike lesions of the peritoneum have overlapping imaging features when compared with each other and primary peritoneal tumors. Knowledge of peritoneal anatomy, normal fluid circulation within the peritoneal cavity, and clinical and pathologic features of secondary peritoneal lesions is essential for identification of these lesions.

肿瘤和瘤样病变二次复发时,如果涉及到腹膜间(mesothelial)皮层或胸膜间(submesothelial)皮层,就是是一个不同病症的集合,呈现出从良性到恶性各种不同的生物学特征。腹膜韧带的解剖学知识和肠系膜和腹水的正常循环决定这些疾病在腹腔内的位置和分布。腹膜种植转移是最常见的影响腹膜腔的继发性肿瘤。当它来自胃肠道或卵巢癌时,预后极差。然而,当低级阑尾粘液型腺癌(mucinous adenocarcinoma of the appendix)扩散到腹腔,结果通常是腹膜假粘液瘤。这是一种临床综合症,由于腹膜表面生长没有显著底层组织入侵,其表现为复发和顽固的大量的粘液性腹水。从身体其它部位的癌、淋巴瘤和肉瘤,也可能产生弥漫性腹膜转移。肉芽肿性腹膜炎是扩散性感染的结果,如结核病传播的感染或组织胞浆菌病,外部组织,或肿瘤以及中空的内脏破裂。最后,一群良性的影响因素,从常见的疾病如子宫内膜异位和脾组织植入到非常罕见的疾病如腹膜胶质瘤和黑变病也可能影响腹膜扩散。肿瘤和瘤样病变二次复发病变和原发性腹膜肿瘤的对比以及各自相比来说,有重叠成像特征。腹膜的解剖知识,正常腹腔内液体循环,二次腹膜病变临床和病理特征对识别这些病变至关重要。

 

腹膜肿瘤的MRI弥散成像 与常规MRI以及手术和病理结果的比较 ——一个可行性的研究。

MATERIALS AND METHODS: Thirty-four consecutive oncology patients underwent preoperative abdominal and pelvic MRI for tumor staging. MRI included breath-hold DWI with a b value of 400-500 s/mm(2),T1-weighted spoiled gradient-echo, T2-weighted fast spin-echo, and 0- and 5-minute delayed gadolinium-enhanced imaging. At three separate sessions, two observers independently reviewed images for peritoneal tumors at 16 anatomic sites. First DWI alone was reviewed, followed by conventional MRI alone, and then conventional MRI, including DWI, was reviewed. Results of laparotomy and histopathologic evaluation were compared with MRI results. Sensitivity, specificity, and accuracy were calculated for DWI, conventional MRI, and combined DWI and conventional MRI for peritoneal tumor depiction.

RESULTS: Two-hundred fifty-five sites of peritoneal tumor were proven by surgical and histopathologic findings. The combination of DWI and conventional MRI was most sensitive and accurate for peritoneal tumors, depicting 230 and 214 tumor sites for the two observers (sensitivity, 0.90, 0.84; and accuracy, 0.91, 0.88) compared with DWI alone, which depicted 182 and 182 tumor sites with sensitivity (0.71, 0.71; and accuracy, 0.81, 0.81), and conventional MRI alone, which depicted 185 and 132 tumor sites (sensitivity, 0.73, 0.52; and accuracy, 0.81, 0.72). Peritoneal tumor showed restricted diffusion on DWI and ascites was of low signal intensity, increasing tumor conspicuity. CONCLUSION: Adding DWI to routine MRI improves the sensitivity and specificity for depicting peritoneal metastases. Breath-hold DWI is now routinely used in all oncology patients referred for abdominal MRI at our institution.

目的:我们研究的目的是评估单发自旋回波-回波平面扩散权重成像的效用(磁共振弥散加权成像) ,使用b值400 - 500 s /毫米)描绘腹膜肿瘤。

材料与方法:连续三十四肿瘤患者接受了肿瘤术前腹部和盆腔MRI肿瘤分期。MRI包括屏息磁共振弥散加权成像的b值400 - 500 s /毫米(2),t1变质破坏梯度,t2加权快速旋转回声和0 - 5分钟延迟钆增强MR成像技术。共分为三个部分,两个观察员独立检查腹膜肿瘤图像的16个解剖部位。第一次是单独的DWI,紧随其后的是常规MRI,然后常规磁共振成像,包括DWI。剖腹手术的结果和病理评价结果与核磁共振的记过比较相比。计算DWI,常规MRI和DWI和常规MRI结合对于腹膜肿瘤描述的敏感性、特异性和准确性。

结果:255个部位的腹膜肿瘤被手术和病理证实的发现。DWI和常规MRI的组合对腹膜肿瘤是最敏感和准确的,两个观察方式分别找出了230个和214个肿瘤位置 (灵敏度,0.90,0.84,和准确性,0.91,0.88),与之相比DWI找出了182个和182个肿瘤位置,敏感性 (0.71,0.71,和准确性,0.71,0.71)。而常规MRI仅描述了185个和132个肿瘤位置(灵敏度,0.73,0.52,和准确性,0.81,0.72)。DWI显示限制扩散的腹膜肿瘤和腹水具有低信号强度,增加肿瘤的可显现程度。

结论:常规MRI再加上加DWI可以提高其在描绘腹膜转移方面的敏感性和特异性。在我们机构屏息DWI是现在通常用于肿瘤病人的腹部MRI的辅助分析。

J Magn Reson Imaging. 2007 Apr;25(4):848-58.

Diffusion-weighted MRI (DWI) in the oncology patient: value of breathhold DWI compared to unenhanced and gadolinium-enhanced MRI.

DWI应用于肿瘤病人:屏息DWI与非增强和钆增强MRI的比较价值

Low RN, Gurney J.

Children’s MRI Center, San Diego, California 92123, USA. rlow@ucsd.edu

PURPOSE: To evaluate the feasibility and added value of single breathhold diffusion-weighted (DW) imaging (DWI) in oncology patients undergoing abdominal MRI. MATERIALS AND

METHODS: A total of 169 patients with malignancy underwent abdominal MRI at 1.5T, including T1-weighted (T1W), T2-weighted (T2W), and dynamic gadolinium-enhanced imaging. Axial DWI was performed with a single-shot spin-echo (SE) echo-planar imaging (EPI) sequence using a b-value of 500 seconds/mm2. A total of 24 slices were obtained during a 20-second breathhold. Two observers reviewed the conventional MR images for tumor. Next, the DW images were reviewed for additional tumor not depicted on conventional MR images

RESULTS: For the 169 patients, additional tumors were noted on the DW images in 77 (0.46) for observer 1 and 67 (0.40) for observer 2. For observer 1 the additional tumor included lymphadenopathy (47), peritoneal metastases (15), renal (1), liver (12), and osseous (2), while for observer 2 the corresponding values were lymphadenopathy (40), peritoneal (12), renal (1), liver (6), osseous (4), and gastrointestinal (1). The DW images resolved as benign findings noted on the conventional MR images in three patients for observer 1 and four patients for observer 2. The conventional MR exam was entirely normal while the DW images showed tumor in 12 (0.07) patients for observer 1 and 10 (0.06) patients for observer 2.

CONCLUSION: DWI is feasible in a single breathhold and provides additional clinically important information in oncology patients when added to routine abdominal MR sequences. Copyright (c) 2007 Wiley-Liss, Inc.

目的:评价单一屏息DWI在肿瘤患者腹部核磁共振的可行性和附加值。

材料与方法:共169例恶性肿瘤患者接受腹部MRI 1.5 t,包括t1(T1W),t2加权(T2W)和功能钆增强成像。轴向DWI使用b值为500秒/平方毫米与单次激发平面回波成像同时实施序列列。总共有24片在20秒的屏息期间获得的。两组观察者回顾了传统图像肿瘤。接下来, DW图像发现了常规MR图像未发现的额外的肿瘤。

描述性结果:对于169名患者, 在DW图像上有发现额外的肿瘤,观察组1发现了77例(0.46),观察组2发现了67例(0.40)。观察组1发现的额外的肿瘤包括淋巴结病(47),腹膜转移(15)、肾(1),肝脏(12),和骨质(2),观察组2相应的是淋巴结病(40),腹膜(12)、肾(1),肝(6)、骨性(4),胃肠道(1)

观察组1中3例和观察组2中4例,在DW图像解析为良性肿瘤,常规MR图像检测则较显著。传统MR检测是完全正常,然而DW成像显示有肿瘤,其中观察组1中12例(0.07),观察组2中10(0.06)例。

结论:单个屏息DWI是可行的,且在作为常规腹部MR序列的辅助检测时,可以提供额外的肿瘤患者的临床重要信息。

版权(c)2007年Wiley-Liss公司。

 

恶性胃肠间质瘤的影像学检查。

 

在这个图片的文章中,我们描写了计算层析,磁共振成像出现原发性和转移胃肠道间质瘤。这些nonepithelial肿瘤起源于固有肌层在胃肠道的墙壁和被认为起源于Cajal间质细胞肠起搏器的组织。这些肿瘤在胃、小肠、结肠、直肠、食道中都有发现;他们也可能成为网膜,肠系膜或腹膜后腔的原发肿瘤。胃肠道基质肿瘤的临床特征和放射诊断也在被讨论。

与本文有关的论文信息:
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