b值的选择对DWI定量测量鉴别甲状腺结节良恶性的影响

目的评价不同扩散敏感因子(b值)的扩散加权成像(DWI)对甲状腺结节定量测量诊断价值的影响。资料与方法 37例甲状腺结节患者,共55处结节,均采用1.5 T MR行DWI,b值分别取150 s/mm2、300 s/mm2、400 s/mm2、500 s/mm2。依据术后病理结果将结节分为良性和恶性组,比较同一b值时不同甲状腺结节之间以及同一结节使用不同b值时平均表观扩散系数(ADC)值的差异。绘制甲状腺良、恶性结节鉴别的受试者工作特征(ROC)曲线,比较不同b值时ROC曲线下面积(Az),确定诊断阈值,评价筛检效能。结果 55处结节,18处为恶性,37处为良性。(1)良、恶性结节的平均ADC值在不同b值时差异均有显著性统计学意义,恶性组平均ADC值均显著低于良性组[b值取150 s/mm2、300 s/mm2、400 s/mm2、500 s/mm2时,恶性组的平均ADC值分别为(1.691±0.36)×10-3mm2/s、(1.577±0.276)×10-3mm2/s、(1.450±0.268)×10-3mm2/s、(1.271±0.313)×10-3mm2/s,良性组的平均ADC值分别为(2.586±0.4...     

软组织肿瘤的MR弥散加权成像初步研究

目的:探讨MR DWI在软组织肿瘤定性诊断中的价值.方法:研究了23例软组织肿瘤DWI.弥散敏感系数b分别取300s/mm2、600s/mm2和900s/mm2,在三个方向施加弥散敏感梯度场得到DWI,获得肿瘤实质的ADC值.结果:①23例软组织肿瘤的DWI只有1例肌间脂肪瘤为混杂信号,其它均为高信号;②在b＝300s/mm2时,良、恶性肿瘤组的ADC值为(1.64±0.12)×10-3mm2/s、(1.86±0.19)×10-3mm2/s,良、恶性肿瘤组间的ADC值差异有显著性;在b＝600s/mm2时,良、恶性肿瘤组的ADC值分别为(1.42±0.13)×10-3mm2/s、(1.46±0.15)×10-3mm2/s,二者之间差异无显著性;在b＝900s/mm2时,良、恶性肿瘤组的ADC值分别为(1.10±0.12)×10-3mm2/s、(1.00±0.13)×10-3mm2/s,二者之间差异无显著性.结论:DWI信号对软组织肿瘤诊断价值有限.在b＝300s/mm2时,恶性软组织肿瘤的ADC值大于良性软组织肿瘤的ADC值.     

女性盆腔病变的扩散加权成像

目的 探讨MR扩散加权成像(DWI)在女性盆腔病变诊断中的价值.方法 对135例女性盆腔病变进行常规MR平扫和DWI,表面扩散系数(b值)分别为0 s/mm2和1000 s/mm2,测量病变的表面扩散系数(ADC)值,其中16例同时行增强扫描.结果 43例子宫恶性病变的平均ADC值为(0.90±0.10)×10-3mm2/s,24例子宫良性病变的平均ADC值为(0.12±0.09)×10-3mm2/s,2组病变之间比较有统计学意义(P<0.01);34例附件区恶性病变的平均ADC值为(0.98 4-0.11)×10-3mm2/s,34例附件区良性病变的平均ADC值为(2.25 4-0.12)×10-3mm2/s,2组病变之间比较有统计学意义(P<0.01).结论 DWI有助于对女性盆腔良恶性病变的诊断和鉴别.     

3.0 T MR DWI在肝脏良、恶性局灶性病变诊断中的初步研究

目的 探讨3.0 T MR扩散加权成像(DWI)在肝脏良、恶性局灶性病变诊断和鉴别诊断中的价值.资料与方法 采用GE 3.0T Signal EXCITE超导型磁共振扫描系统对47例肝脏局灶性病变(57个病灶)行DWI,其中25例良性病变30个病灶,22例恶性病变27个病灶.b值选用0、500、1000 s/mm2,测量病灶的表观扩散系数(ADC)值并进行统计学分析.用受试者工作特征(ROC)曲线评价ADC值对肝脏良、恶性病变的诊断价值.结果 b值为500 s/mm2和1000 s/mm2时,良性病变的ADC值分别为(3.12±1.58)×10-3mm2/s、(2.23±1.01)×10-3 mm2/s;恶性病变的ADC值分别为(2.01±0.95)×10-3mm2/s、(1.31±0.37)×10-3 mm2/s,两者之间差异有统计学意义(P<0.01).ROC曲线评价ADC值诊断肝脏良、恶性病变的曲线下面积、敏感性、特异性、准确性、阳性预测值、阴性预测值分别为0.799、77.8%、76.6%、77.2%、75.0%、79.3%和0.852、81.5%、90.0%、85.9%、88%、84.3%.结论 3.0 T MR DWI ADC值在肝脏良、恶性病变的鉴别中具有重要参考价值,且b值为1000 s/mm2时所测ADC值较准确.     

表观扩散系数值鉴别良恶性骨肿瘤及肿瘤样病变的价值

目的 探讨MR DWI的ADC值鉴别良、恶性骨肿瘤及肿瘤样病变的价值.方法 对18例良性骨肿瘤及肿瘤样病变和26例恶性骨肿瘤行DWI.采用单激发EPI序列,3个扩散敏感梯度,b值分别为0.500、1000 s/nun2.在ADC图上测量每个病变的最低、最高和整体ADC值.结果 良性骨肿瘤及肿瘤样病变的最低ADC值[(1.28±0.49)×10-3mm2/s]高于恶性骨肿瘤[(0.92±0.35)×10-3mm2/s,t=2.839,P<0.01],整体ADC值[(1.62±0.51)×10-3mm2/s]也高于恶性骨肿瘤[(1.21±0.36)×10-3mm2mm/s,t=3.092,P<0.01],但两者都有很大重叠.良性骨肿瘤及肿瘤样病变的最高ADC值[(2.02±0.55)×10-3mm2/s]与恶性骨肿瘤的最高ADC值[(1.71±0.65)×10-3mm2/s]差异无统计学意义(t:1.669,P＞0.05).去掉以囊腔为主的骨囊肿及动脉瘤样骨囊肿病例,则良性骨肿瘤及肿瘤样病变的最低、最高和整体ADC值分别为(1.11±0.31)×10-3mm2/s、(1.88±0.49)×10-3mm2/s和(1.45±0.35)×10-3mm2/s,与恶性骨肿瘤比较差异无统计学意义(t值分别为1.728、0.964、2.012,P值均>0.05).结论 ADC值不能鉴别良、恶性骨肿瘤及肿瘤样病变.     

扩散加权成像鉴别肺恶性肿瘤与实性良性病变的初步研究

目的探讨扩散加权成像(diffusion-weighted imaging,DWI)对肺恶性肿瘤与实性良性病变的鉴别诊断价值。资料与方法62例肺内恶性肿瘤和实性良性病变(共66个病灶)行常规MRI和DWI检查,b值为500s/mm2,观察病变区DWI信号特点并测量其表观扩散系数(apparent diffusion coefficient,ADC)值。结果不同病变组DWI信号虽有一定特点,但不具特征性。恶性病变组和良性病变组ADC值分别为(1.256±0.320)×10-3mm2/s、(1.648±0.416)×10-3mm2/s,两者差异有统计学意义(t=-3.637,P=0.001),ADC值鉴别肺内良恶性病变的最佳诊断阈值为1.400×10-3mm2/s,敏感性和特异性分别为83.3%和74.1%;小细胞肺癌ADC值为(1.064±0.196)×10-3mm2/s,非小细胞肺癌ADC值为(1.321±0.335)×10-3mm2/s,两者差异亦有统计学意义(t=2.967,P=0.007);原发性肺癌ADC值为(1.255±0.328)×10-3mm2/s,肺转移瘤ADC值为(1.263±0.280)×...     

不同扩散梯度因子值的乳腺MR扩散加权成像对比研究

目的 确定一个最佳的用于乳腺MR DWI的b值.方法 按照前瞻性设计,选取怀疑乳腺癌的乳腺可触性包块患者40例,术前行双侧乳腺MR和DWI扫描,b值分别取1000、800和600 s/mm2,肉眼判断DWI图像等级,采用单因素方差分析比较3组b值的DWI像信噪比和病灶ADC值,采用ROC曲线评价ADC值诊断价值.结果40例患者中乳腺癌26例,良性肿块14例,DWI显示36例,共42个病灶.3组b值下的DWI图像质量均较好,加例中视觉分级达A级的分别占75.0%(30例)、77.5%(31例)和77.5%(31例).3组b值DWI图像对病灶的检出能力相同.b=1000、800和600 s/mm2的信噪比平均值分别为63±22、82±27和96±29,3组间比较差异具有统计学意义(P<0.01).良性病变平均ADC值分别为(1.44±0.28)× 10-3、(1.50±0.32)×10-3和(1.52±0.29)×10-3mm2/s,3组间比较差异无统计学意义(P=0.725).恶性病变平均ADC值分别为(1.00±0.25)×10-3、(0.98±0.19)×10-3和(1.07±0.22)×10-3mm2/s,3组间比较差异也无统计学意义(P=0.358).3组b值的ADC值诊断乳腺良恶性病变的ROC曲线下面积分别为0.879、0.885和0.865;诊断良恶性病变的阈值分别为1.295×10-3、1.435×10-3和1.335×10-3mm2/s;诊断乳腺癌的敏感性分别为80.0%、92.0%和84.0%,特异性均为90.0%;阳性预测值分别为95.2%,95.8%和95.5%.结论综合图像信噪比和ADC值诊断价值,认为在乳腺DWI中,b=800 s/mm2是乳腺DWI成像的最佳b值.     

磁共振扩散加权成像在甲状腺良恶性病变鉴别诊断中的价值

目的：探讨MR扩散加权成像在甲状腺良恶性病变鉴别诊断中的价值。方法：采用平面回波成像（EPI）技术。对50例甲状腺局灶性病变（良性组36例,恶性组14例）行DWI检查,分别测量b值取0、150、300和500s/mm2时良恶性病灶的信号强度和ADC值,并比较其差异。所有患者均经手术（49例）或活检（1例）病理证实。结果：良性与恶性病变的信号强度在b值为0、150、300和500s/mm2时差异均无统计学意义（P〉0.05）。b值为150、300和500s/mm2时良性组与恶性组之间ADC值的差异均有统计学意义（P〈0.01）。以恶性组ADC值95%可信区间上限作为诊断阈值,则b值为150、300和500s/mm2时,诊断阈值分别为1.992×10^-3、1.582×10-3和1.410×10-3mm2/s。应用ROC曲线分析不同b值时ADC阈值诊断恶性病变的作用,显示b值为150s/mm2时价值最大,其诊断敏感度、特异度、符合率、阳性和阴性预测值分别为78.57%、84.62%、82.50%、73.33%和88.00%。结论：甲状腺恶性病变的ADC值低于良性病变,b值取150s/mm2、阈值设为1.992×10-3mm2/s有助于良恶性病变的鉴别。     

磁共振扩散加权成像对椎体良恶性骨折的鉴别诊断价值

目的探讨磁共振扩散加权成像(DWI)在椎体良恶性骨折中的鉴别诊断价值。方法31例共58个病变椎体均做了MRI常规扫描和扩散加权成像,良性组20例32个骨折椎体,恶性组8例18个椎体,结核组3例8个椎体,正常对照组31个椎体。b值为600s/mm2,分析病变椎体与正常椎体DWI信号特点,并测定ADC值,定量分析比较病变组与对照组之间,良、恶性组,恶性组与结核组之间ADC值有无统计学差异。结果良性组、恶性组、结核组以及对照组ADC值分别为(1.44±0.41)×10-3mm2/s、(0.94±0.17)×10-3mm2/s、(0.98±0.13)×10-3mm2/s、(0.42±0.16)×10-3mm2/s。病变组ADC值均显著高于对照组(P<0.001),良性组明显高于恶性组(P<0.01),恶性组与结核组无统计学差异(P>0.05)。以恶性组95%可信区间上界1.02×10-3mm2/s定为良恶性椎体骨折ADC值界值,诊断敏感性72.2%,特异性90.6%。结论DWI对脊椎良恶性骨折具有重要的鉴别诊断价值,可作为常规MRI检查的重要补充手段。     

Application of Diffusion Weighted Imaging in Differential Diagnosis of Benign and Malignant of Stomach Neoplasm

目的 探讨扩散加权成像(diffusion-weighted imaging,DWI)及其表观扩散系数(apparent diffusion coefcient,ADC)在胃良、恶性肿瘤鉴别中的价值,确定ADC值在良恶性肿瘤鉴别中的最佳临界点.方法 39例经手术或胃镜活检病理证实的胃肿瘤性病变患者,进行常规MRI及DWI,b值采用800 s/mm2,以病理结果为金标准,统计分析胃良性和恶性占位之间的ADC值差异.结果 当b值为800 s/mm2,良性组ADC平均值为(2.200±0.959)× 10-3mm2/s,恶性组ADC平均值为(1.89±0.463)× 10-3mm2/s,两组间有显著差异(F=25.12,P＜0.05).受试者工作特征(ROC)曲线显示,区别良恶性胃部肿瘤的最佳临界点为1.915×10-3mm2/s,其敏感性为88.7％,特异性为91.1％,约登指数为0.798.结论 DWI在胃肿瘤诊断中具有可行性.b值为800 s/mm2时,胃良性和恶性肿瘤之间的ADC值存在显著统计学差异,区别胃部良恶性肿瘤的最佳临界点为1.915×10-3mm2/s,ADC值对于鉴别胃良恶性肿瘤有辅助诊断价值.     

Optimization of the system of medical service of students of Cadet Schools of the Ministry of Defense of the Russian Federation

One of the factors of the successful military career guidance Cadet schools students is preserving and promoting their health. Medical support of children and adolescents aged 10-17 years should include the full range of medical and preventive measures defined for this group. The state of providing outpatient care for pupils at the Cadet School in St. Petersburg was studied. These results show that full medical care in accordance with the standards can be based only on children's health clinics. It is important that the organization of medical support pupils cadet schools should be cooperate with civilian health care.     

带状疱疹83例误诊原因分析

带状疱疹是由水痘—带状疱疾病毒引起的皮肤科常见疾病。其主要的病理损害,一是受累神经的严重炎症性浸润,继而导致受侵犯神经节内神经细胞变性、坏死;二是皮肤的水泡。迅速抑制神经节和相应的感觉神经纤维的充血、水肿和坏死,防止粘连形成,达到迅速镇痛、改善皮损,缩短病程及防止后遗症的发生是治疗的关键。因而,尽早明确诊断,     

Estimation of accumulated dose of radiation by method of ESR-spectrometry of dental enamel of mammals

ESR-spectrometry was used to investigate radiation-induced paramagnetic centers in enamel of mammals: carnivores (polar bear and fox), ungulates (reindeer, European bison, moose), and man. Values at half the microwave power saturation of the radiation signal, P_1/2, evaluated at room temperature, was found to range from 16 to 26 mW for animals and man. A new approach to discrimination of the radiation induced signal from the total ESR spectrum of reindeer enamel is proposed. ‘Dose-response’ dependencies of enamel of different species mammals were measured within the dose range from 0.48 up to 10.08 Gy. Estimations of ‘radiosensitivity’ enamel of carnivores and ungulates showed good agreement with radiosensitivity enamel of man by ESR method.     

Analysis of the results of the international comparison of activity measurements of a solution of Fe

The results of an international comparison of activity measurements of a solution of ⁵⁵Fe organized by the BIPM in 2005 are reported and analysed. This exercise, which follows the procedures of the CIPM mutual recognition arrangement to update older comparisons, is a renewal of the comparison organized by the BIPM that took place in 1978. A EUROMET comparison was organized in 1996 specifically to compare activity measurements of a ⁵⁵Fe solution by means of liquid-scintillation techniques. Results of these three comparisons are presented and discussed in this paper.

The radionuclide solution was provided by the NPL, which also distributed the samples to the participants. The activity of the ampoules was measured by 16 laboratories using 12 methods producing 25 results. Some general considerations on uncertainty assessments pertaining to the different techniques used are drawn. The outcome of four different estimators is compared from which the presence of at least one outlier can be confirmed. Further measurements should be made to try to reduce the discrepancy between the results. To date the outcome of the present comparison does not show an improvement to that of the 1996 comparison.     

Evaluation of the results of various technics of non-surgical therapy of varicocele

A new method of non-surgical treatment of varicocele syndrome is described: it consists in sclerotherapy of spermatic vein by trans-femoral percutaneous catheterization with balloon-catheters. In 8 cases venous thrombosis has been induced by direct electric clotting. The techniques and a 6 months follow-up are discussed. It is pointed out that this procedure should be considered as the method of choice for tubular lesions and sub-fertility prophylaxis in young people and in childhood.     

延迟性脾破裂误漏诊原因分析

目的探讨延迟性脾破裂误漏诊原因和预防措施.方法回顾性分析总结12例延迟性脾破裂中的诊断和误漏诊的经验与教训.结果本组延迟性脾破裂的误漏诊5例(41.66%).对多发伤与脾破裂并存可能认识不足,外伤史轻微或伤员隐瞒外伤史,缺乏腹痛-缓解-突然再腹痛的典型病史,缺乏“对冲性脾破裂”力学分析和整体化诊断思路等为其误漏诊的主要原因.结论详细的外伤史和全面系统检查,重视腹以外多发伤掩盖腹内脏器伤及延迟性脾破裂可能.确立外伤-腹内脏器伤-脾破裂整体化诊断思路.不间断地辅以B超检查脾形态学变化和腹内有无积液,腹腔穿刺确定有无血腹、X线胸腹部检查观察左侧胸肋角和膈肌运动情况、必要时CT检查以尽早发现脾包膜下血肿,降低延迟性脾破裂误漏诊率.