磁共振射频线圈单元数对图像信噪比的影响

在磁共振成像过程中,射频线圈用来接收信号,对成像的质量起着至关重要的作用。用户在采购磁共振设备时往往用线圈的通道数和单元数来评价一个线圈的成像能力,而线圈的通道数又必须和系统的接收通道数相匹配,因此一般认为,在系统其他条件一定的情况下,线圈的单元数越多,成像质量越好。本文以PhilipsAchieva3．0T磁共振为平台,分别选取78通道8单元的SenseHead（头部）线圈和16通道18单元的SenseNeurovascular（神经血管）线圈作为比较对象进行扫描,比较两者成像的信噪比。另外,选取15通道15单元SenseSpine（全脊柱）线圈,先后用不同数量的采集单元数成像,然后对信噪比进行评价。     

Treatment of hepatocellular carcinoma adjacent to large blood vessels using 1.5T MRI-guided percutaneous radiofrequency ablation combined with iodine-125 radioactive seed implantation

Objective

The objective is to study the technology associated with and feasibility of the treatment of hepatocellular carcinoma (HCC) adjacent to large blood vessels using 1.5T MRI-guided radiofrequency ablation combined with iodine-125 (I-125) radioactive seed implantation.

Methods

Sixteen patients with a total of 24 HCC lesions (average maximum diameter: 2.35 ± 1.03 cm) were pathologically confirmed by biopsy or clinically diagnosed received 1.5T MRI-guided percutaneous radiofrequency ablation (RFA) treatment. Each patient had one lesion adjacent to large blood vessels (≥3 mm); after the ablation, I-125 radioactive seeds were implanted in the portions of the lesions that were adjacent to the blood vessels.

Results

All the ablations and I-125 radioactive seed implantations were successful; a total of 118 seeds were implanted. The ablated lesions exhibited hypointense signals on the T2WI sequence with a thin rim of hyperintense signals; they also exhibited significant hyperintense signals on the T1WI sequence with clear boundaries. The average follow-up period was 11.1 ± 6.2 months. There were 23 complete responses and one partial response in the 24 lesions. The alpha-fetoprotein (AFP) levels of the patients significantly decreased.

Conclusion

The 1.5T MRI-guided RFA combined with I-125 radioactive seed implantation for the treatment of HCC adjacent to large blood vessels is an effective technology.     

低温等离子射频消融治疗睡眠呼吸暂停低通气综合征

目的探讨低温等离子射频消融术治疗阻塞性呼吸暂停低通气综合征（OSAHS）的疗效及安全性。方法选择45例轻、中度OSAHS的患者,根据阻塞部位的不同应用低温等离子射频打孔刀进行治疗。结果术后6个月随访,45例患者中治愈6例,显效22例,有效12例,无效3例,失访2例,总有效率88.88%。结论应用低温等离子射频消融术治疗OSAHS安全可行,值得推广。     

超声引导下射频消融治疗子宫肌瘤疗效分析

目的：采用超声引导下射频消融治疗子宫肌瘤。探讨微创技术治疗子宫肌瘤的临床效果。方法：对自愿接受射频消融自凝刀治疗的60例子宫肌瘤患者，其中粘膜下肌瘤9例，壁间肌瘤51例，在超声引导下将自凝刀经阴道置入肌瘤进行射频消融治疗。结果：治疗后随访3、6个月，瘤体缩小率100％。9例粘膜下肌瘤患者术后月经恢复正常；26例擘间肌瘤经节增多者中．术后3、6个月经节恢复正常者达83．3％、95．4％。结论：射频消融自凝刀治疗子宫肌瘤是一种微创并保留子宫的好方法，方法简单、安全、易推广。     

射频消融(RFA)治疗肝癌的临床研究

目的 探讨射频消融治疗肝癌的临床疗效及安全性。方法 从1999年5月-2007年5月期间对1200例肝癌患者,其中原发性肝癌患者947例,转移性肝癌患者253例,在B超引导下进行集束电极射频消融治疗,通过手术前后对病灶采用CT、B超观测的比较,了解肿瘤大小、数量及血清AFP变化情况,通过术后观察和随访,了解其治疗疗效。结果1,本组病例的1年、3年和5年存活率分别为：67．48％、54．63％、35．82％;2,6月后病灶完全缓解（CR）：12．75％（153／1200）;部分缓解（PR）：74．33％（892／1200）,总有效率为：87．08％;3,患者治疗后腹痛、腹胀症状减轻,生活质量明显提高;4,治疗后并发症少,未出现与治疗有关的死亡。结论：射频消融治疗小肝癌（直径≤5Cm）疗效较佳,对不能切除的大肝癌和转移性肝癌亦是一种高效、安全的治疗方法,其近、远期疗效确切。     

Microbubble-induced increase in ablation of liver tumors by high-intensity focused ultrasound

We studied the possibility of using high-intensity focused ultrasound (HIFU) together with a microbubble agent to treat hepatocellular carcinoma. Development of liver tumors in rats was induced by administration of Dimethylnitrosamin (100ppm). Rats with liver tumors were anesthetized, underwent laparotomy, and were given the microbubble agent Levovist or saline intravenously. After the injection, the liver was exposed to HIFU for 30s (2.18MHz, 600W/cm(2), 40mm in diameter). Immediately after HIFU exposure, ultrasound images of the HIFU area were evaluated. Then the liver was excised and the volume of coagulated tissue was measured. The mean volumes of hyperechoic areas after HIFU were as follows (mm(3), Levovist versus saline: 355.3+/-180.7 versus 47.4+/-35.6, P<0.001, n=13). The volumes of liver tissue coagulated by HIFU were as follows (mm(3), Levovist versus saline: 275.3+/-120.0 versus 60.1+/-23.6, P<0.001, n=13). On microscopic examination of areas exposed to HIFU, implosion cysts were seen, and many cancer cells were found to have been destroyed completely (loss of cell membranes or nuclei). In conclusion, the microbubble agent Levovist can increase the volume of tissue coagulated by HIFU.     

内窥镜射频固化疗法治疗胃肠息肉

目的：研究内窥镜射频固化治疗胃肠道息肉的疗效。方法：胃肠道息肉患30例，54颗息肉，采用电子胃镜或电子肠镜及射频治疗仪进行内镜下射频治疗。结果：经1次射频治疗消失的病灶50个，2次治疗消失的4个，随访个月未见复发。结论：内窥镜射频固化治疗胃肠息肉，疗效明显，副作用小，是治疗胃肠道息肉的较好方法。     

多弹头射频治疗小肝癌

探讨多弹头射频治疗小肝癌的疗效及价值.对43例小肝癌患者行射频治疗,术中直视肿瘤射频治疗前后的图象及CT值,术后观察肿瘤大小,血供情况及AFP值的变化.结果显示:完全缓解率(CR)95.35%;部分缓解率(PR)4.65%;有效率100%.多弹头射频治疗小肝癌疗效确切而满意,对临床有较高的应用价值.     

等离子刀射频消融治疗椎间盘突出症

目的:探讨等离子刀装置进行颈、腰椎间盘突出症射频消融方法及影响治疗效果的因素。方法:80例颈、腰椎间盘突出症患者,在C型臂血管造影机监测下穿刺病变椎间盘,置入等离子消融电极刀进入髓核,进行射频消融处理3-5 m in.结果:椎间盘穿刺顺利,一次穿刺成功率100%。射频消融作用时间平均3.5 m in,症状消失38例,明显好转29例,中度好转8例,5例无效,无明显并发症。结论:用等离子装置进行椎间盘髓核射频消融是治疗椎间盘突出症的有效而安全的新方法,利用适当的剂量和积极的手术后处理可以达到满意的临床疗效。     

Neurological abnormalities associated with mobile phone use

Dysaesthesiae of the scalp after mobile phone use have been previously reported but the pathological basis of these symptoms has been unclear. We report finding a neurological abnormality in a patient after prolonged use of a mobile phone. He had permanent unilateral dysaesthesiae of the scalp, slight loss of sensation, and abnormalities on current perception threshold testing of cervical and trigeminal nerves. A neurologist found no other disease. The implications regarding health effects of mobile phones and radio-frequency radiation is discussed.