磁共振成像(MRI)在肺癌诊断中的价值(附40例分析)

笔者分析了40例支气管肺癌的MRI表现,评价了MRI在肺癌诊断中的价值。着重指出MRI最大优点是多参数、多方位成像,对肺内病变可以准确定位,有利于指导外科手术。MRI可以分辨肺癌肿块与肺不张和阻塞性肺炎,并可以分辨放疗后放射性纤维化与肿块或肿瘤复发。MRI对周围型肺癌可以得到比平片、CT更多的信息,可以清楚的显示肿瘤坏死、囊变以及出血。可以显示肿瘤侵犯气管、支气管、血管及胸膜、胸壁。对术前判断肿瘤能否切除,以及肿瘤的分期和制定治疗方案都有十分重要的意义。     

Informed consent in radiation oncology: is consenting easier than informing?

The patient’s right to be informed has been universally recognized and reflected in the legal system of many countries. This right to correct and complete information on behalf of the patient and his admission to proceed with the recommended diagnostic or therapeutic procedure is formalized in the document commonly known as informed consent. Although the legal and bioethical considerations regarding this document have been exhaustively discussed and consensuated, its content continues to create certain doubts and uncertainties. The formal content and the manner in which the consent is obtained are the most difficult aspects. In this article, we analyze what should be included in the written informed consent, with regard to the totality of the information which the patient receives, who should inform, and how the consent should be obtained, as well as how to reflect the different aspects of the variety of radiotherapeutic procedures in the informed consent.     

双源CT前瞻性心电门控序列扫描冠状动脉成像准确性的多中心研究

Objective To investigate the accuracy of low-dose dual-source computed tomography (DSCT) coronary angiography in the step-and-shoot (SAS) mode for the diagnosis of coronary artery stenosis in comparison with conventional coronary angingraphy (CCA).Methods Prospective multiple-center study, 46 patients[mean age(58±9) years;bedy mass index(BMI) (25±3) kg/m2]underwent both DSCT in the SAS mode and CCA within 14 days.The inclusion criteria for contrast-enhanced CT: (1) heart rate less than 65 times/rain (bpm).(2) regular sinus rhythm, heart rate fluctuations within the range of 6 bpm. (3) holding breath well, breath-hold time is about 12-15 s.The exclusion criteria:(1) allergy to iodinecontaining contrast medium, nephropathy (serum creatinine level 120 μmol/L), heart failure and serious arrhythmias.(2) patients with coronary stents or bypass grafts.(3) heart rate can not be controlled very well (4)the patient could not take nitroglycerin.(5)BMI 30 kg/m2.(6) other heart disease: carcliomyopathy, valvular disease etc.Sensitivity, specificity, negative (NPV) and positive predictive value (PPV) were determined with CCA as standard of reference.The Kappa value between the two modalities and the two observers was calculated.Radiation dose values were measured.Results Mean heart rate during scanning was (61±6)bpm.99.19% (614/619) coronary segments were depicted with a diagnostic image quality. The vessel-based sensitivity, specificity, PPV, and NPV for the diagnosis of coronary artery stenosis were 96.2% (75/78), 88.2% (60/68), 90.4% (75/83), and 95.2% (60/63), respectively.The Kappa value between the two modalities was 0.848 (P=0.000).The mean effective dose of the SAS-CTCA was (2.95± 0.96) rosy(1.26-4.32 mSy).Conclusion In selected patients, DSCT coronary angiography in the SAS mode have good image quality, which allows for the accurate diagnosis of coronary stenosis at a low radiation dose.     

Radiofrequency shielding of surface coils at 4.0 t

Because radiation loss associated with a radiofrequency (RF) coil increases as roughly the fourth power of the frequency, this loss mechanism may become important in high-field studies above 2.0 T. In this study, the contribution of radiation losses at 4.0 T were determined in a rectangular surface coil using an RF shield to modify the radiation losses. The effect of this shield was determined on coil Q, B₁ distribution, and signal to noise as a function of distance between the coil and the shield. Phantoms and human tissue were evaluated to characterize the loss mechanisms. The results demonstrate a large radiation loss in the unshielded surface coil. However, the radiation losses in vivo were not dominant owing to a large inductive loss occurring from dielectric currents in the body at 170 MHz.     

MEBO治疗4例放射性顽固性溃疡的体会

目的：寻求简单有效治疗放射性顽固性溃疡方法。方法：全程应用湿润暴露疗法(MEBT)。结果：4例放射性顽固溃疡创面全部愈合。结论：烧伤湿润暴露疗法，对放射性顽固性溃疡治疗效果满意。     

γ源放射事故受照者呕吐开始时间与全身剂量关系

目的探讨γ源放射事故受照者呕吐开始时间与全身吸收剂量之间的关系。方法采用STATA统计软件包对39例γ源放射事故受照者资料进行回顾性分析。结果全身吸收剂量等于或大于1Gy的受照者呕吐发生率(2227)显著大于剂量在1Gy以下的受照者(112,P<0.001)。出现呕吐的受照者,呕吐开始时间(TD,以h表示)与全身吸收剂量D(Gy)之间的关系符合幂函数模型,其方程式可描述为:TD=(17.45±1.77)D-(2.21±0.30)(n=23,F=50.01,P<0.01,经校正的R2=0.8099)。受照后呕吐开始时间在2h以内的P25、P50和P75剂量分别为4.1、7.6和11Gy;呕吐开始时间大于2h的P25、P50和P75剂量分别为2.0、2.4和2.6Gy。结论在突发核或放射事件可能涉及大量患者的情形下,呕吐开始时间可作为早期分类的一个快速而实用的观察指标,但应注意其局限性。     

Added copper filtration in digital paediatric double-contrast colon examinations: effects on radiation dose and image quality

Paediatric double-contrast barium enema examinations are usually performed at high tube voltage, 102–105 kV. The aim of this study was to investigate how much the effective dose to the child could be reduced by increasing the X-ray energy further by adding copper filter in the beam, and if this dose reduction could be achieved without endangering image quality. Organ doses to an anthropomorphic phantom simulating a 1-year-old child was measured using thermoluminescence dosimetry for assessment of the effective dose and this value was compared with the energy imparted which was obtained from kerma-area product measurements. To verify that the image quality achieved with this added filtration was still diagnostically acceptable, the study included 15 patient examinations. Since the increased X-ray energy will most probably affect low-contrast objects, image quality was also evaluated with two different phantoms containing low-contrast objects. Effective dose for a complete examination can be decreased 44 % and energy imparted 77 % when a 0.3-mm copper filter is inserted in the beam at tube voltage 102 kV. The patient study did not show any significant deterioration of image quality, whereas phantom measurements of contrast-detail resolution and signal-to-noise ratio was marginally impaired by the added copper filtration. This technique is now in clinical practice for paediatric colon examinations. Received 31 July 1996; Revision received 23 December 1996; Accepted 12 February 1997     

引起放射性肺炎的相关因素及HRCT表现与预后的关系

目的 :分析引起放射性肺炎的相关因素 ,HRCT表现与预后的关系。材料和方法 :对 5 80例胸部肿瘤中放射性肺炎的 86例行HRCT检查 ,观察其征象与预后的关系。结果 :总结 7种引起放射性肺炎的相关因素。将HRCT表现分为4种类型 :片状渗出型。补丁实变型。含气不全型和浓密纤维化型。同时探讨了与预后。结论 :阐述引起放射性肺炎的相关因素及HRCT对胸部肿瘤患者与各型放射性肺炎预后的关系。正确使用肺组织的放射剂量 ,定期HRCT检查对放射性肺炎的早期诊断和预后有指导意义。     

MgSO4对大鼠急性放射性脑损伤后钙超载的抑制作用

目的探讨硫酸镁对电离辐射诱发的脑组织损伤的脑保护作用。方法将成熟的SD大鼠60只随机分为空白对照组、实验对照组和硫酸镁实验用药组，用6MeV电子线对实验大鼠进行20Gy全脑单次垂直照射，分别于1、7、14和30d处死、取样，应用等离子直读光谱仪定量分析大鼠脑组织中钙、镁离子含量，用干一湿重法测定脑组织含水量，并与空白对照组进行比较。同时对各组大鼠脑组织进行了病理观察。结果与空白对照组相比，实验对照组大鼠脑水肿明显，脑组织中钙离子含量显著升高（P〈0．05），镁离子含量显著下降（P〈0．05）；与实验对照组相比，硫酸镁实验用药组大鼠脑组织Ca^2＋变化不大，脑水肿程度较前者轻（P〈0．05）。结论早期使用硫酸镁可抑制辐射引起的脑组织中钙离子的超载，减轻脑组织水肿和损伤的程度。     

Craniopharyngiomas of childhood: the CHLA experience

Objective To improve the outcome of children with craniopharyngiomas by analyzing how they were treated.Methods The records of patients who underwent operation at Childrens Hospital of Los Angeles (CHLA) from 1993 to 2004 were reviewed.Results Identified were 19 girls and 16 boys with an age range from 9 days to 16 years (mean 7 years, mode 3 years). Tumor control was achieved in 34 of 35 patients and was accomplished with reasonable outcome in terms of neurological deficits and overall level of function. In 25 patients, complete tumor resection was obtained with surgery alone, 18 with the first resection, and 7 with repeat operative intervention. Nine children received radiation therapy after the first or second recurrence. On retrospective review, there were no consistently identifiable features that would lead one to determine preoperatively which tumors would fall into a given category.Conclusion We believe that the surgeon must determine a preoperative plan that maximizes the chance for a gross total removal of the craniopharyngioma. The biggest challenge intraoperatively is to determine whether to continue with the attempt at gross total removal or stop short of that goal before producing a significant irreversible neurological deficit. A staged removal using different operative corridors also needs to be considered.