多参数磁共振成像评估局部进展期直肠癌新辅助放化疗疗效的研究进展

新辅助放化疗是目前局部进展期直肠癌标准治疗模式的一部分,可以使一定比例的患者达到肿瘤完全缓解,进而提高手术切除率和保肛率,延长患者无病生存期。MRI是评估直肠癌新辅助放化疗疗效的首选影像学检查。随着功能MRI技术的发展,不同成像原理衍生的定量参数可以提供更多的肿瘤生物学信息,提高MRI的临床应用价值。常规MRI序列与功能成像序列相结合的多参数MRI技术可以更加全面地评估新辅助治疗疗效,有助于临床实践中为患者制订个体化的治疗方案,实现精准医疗。     

18F-FDG PET/MR在评估局部进展期直肠癌新辅助放化疗效果中的价值

目的:评估局部进展期直肠癌患者新辅助放化疗(NCRT)前后 18F-脱氧葡萄糖(FDG)PET/MR参数及其变化在预测及评价疗效中的价值。 方法:回顾性分析2017年6月至2020年6月期间在解放军总医院第一医学中心病理学确诊并行NCRT的局部进展期直肠癌患者13例[男9例、女4例,年龄(52.2...     

新辅助放化疗前预判直肠癌病人的治疗反应：多参数MRI与FDG-PET/CT的联合应用价值

正目的探讨新辅助放化疗前,联合多参数MRI及FDG-PET/CT预判直肠癌病人治疗反应的应用价值。方法回顾性分析61例局部进展期直肠癌病人,均具备基线FDG-     

直肠癌高分辨MRI临床研究相关进展

高分辨力MRI能较清晰显示直肠癌及周围组织的解剖结构,根据肿瘤大小、肠壁及浸润深度、局部及远处淋巴结转移情况对直肠癌进行T分期、N分期、M分期,对直肠癌直肠系膜全切除术后环周切缘状态进行评估,运用扩散加权成像、动态增强MRI、体素内不相干运动等新技术评估直肠癌新辅助放化疗疗效、预后等,指导临床医生选择合理的治疗方案,降低患者术后的复发率,提高患者生活质量,延长患者生存时间.本文就目前高分辨力MRI在直肠癌中的临床研究进展作一简要综述.     

MRI和DWI诊断放化疗后器官保留治疗的直肠癌病人长期随访中的局部肿瘤复发

摘要目的评价MRI和DWI对放化疗后器官保留治疗的直肠癌病人随访中肿瘤局部复发的价值。方法 72例行器官保留治疗(放化疗+经肛门内镜显微手术或"等待和观察")的病人进行了MRI包括DWI(1.5 T)随访,第1年每3个月1次,随后几年每6个月1次。2名阅片者按置信度对每份MRI局部肿瘤的复发情况进行了评分,先观察常规MRI,然     

磁化传递成像评估直肠癌放化疗后肿瘤反应

正摘要目的用单层磁化传递(MT)成像评估放疗后纤维化已经取得了满意的成果。本次研究旨在通过肿瘤磁化传递率(MTR)与组织病原学的肿瘤消退程度分级比较来探讨多层MT成像评估放化疗后肿瘤反应的诊断价值。材料与方法30例局部直肠癌晚期(c T3-4和/或c N2)病人在放化疗后的8周行常规MRI检查,包括整个肿瘤的多层MT序列扫描。2名医生分别在MTR图上选取兴趣区,包含所有潜在残留肿     

多发性骨髓瘤病变体素内非相干运动扩散加权成像:与全身动态对比剂增强MR成像相关性

正摘要目的评估3期多发性骨髓瘤(MM)病人系统治疗前后在骨髓及局部病灶检出中体素内非相干运动(IVIM)扩散加权成像(DWI)参数与全身(WB)动态对比增强(DCE)MR成像参数间的相关性。方法研究经本机构伦理委员会批准,27例MM病人被纳入研究。免除书面知情同意。所有病人治疗前均行WB DCE MRI检查,18例病人治疗3个月后重复MRI检查。横断面IVIM DWI序列在骨髓和局部病灶中选用10个b值(0、10、20、30、50、80、100、200、400、800 s/mm~2)。在     

局部进展期直肠癌：综合化疗的新辅助放疗后的MR影像再分期。第一部分：我们能否预测肿瘤局限于直肠壁内？

目的回顾性地评价MR成像对于评价局部进展期直肠癌病人在采取综合化疗的放疗后肿瘤缩小范围局限于直肠壁内（即T0-2期）的诊断价值。材料与方法本研究由学术委员会批准而无需病人知情同意。67例病人满足本研究要求。在综合化疗的放疗前后进行了T2W MRI，由腹部放射学专家、结肠直肠外科医生和普通放射学医生对肿瘤进行分期评价。     

直肠MRI对直肠癌术前T分期评估的研究进展

直肠MRI是直肠癌术前分期的首选检查方法。高分辨T₂WI可显示直肠癌的位置、形态及信号,通过判别肿瘤的浸润深度来评估直肠癌的T分期;还可以识别直肠癌壁外血管内侵犯、环周切缘阳性等预后不良因素,从而指导选择最佳治疗方案。增强T₁WI可显示病变区是否存在完整的黏膜下强化带,结合形态学特征准确地区分T₁及T₂期肿瘤。基于直肠壁各层及周围结构的MRI征象,对直肠MRI评估直肠癌术前局部T分期的研究进展进行综述。     

3.0T MR高分辨率成像对直肠癌局部浸润的术前影像学评价

目的 探讨3.0T MR高分辨率成像在直肠癌术前局部浸润的评估价值.方法 回顾性分析经手术病理证实的直肠癌患者168例,术前均行MRI常规盆腔、直肠高分辨成像.评价3.0T MR高分辨成像术前T分期的准确性;探讨T3期直肠癌局部浸润特征性影像学表现.结果 直肠癌累及肠周径程度与病理T分期呈中等正相关(rs=0.530, P=0.003).MRI直肠癌T分期与病理T分期比较,总体诊断准确度为84.52%,各分期MRI征象与病理T分期有较强的相关性(rs=0.837,P=0.001).MRI诊断T3期直肠癌中,各单一征象以肿瘤结节样外凸特异性最高(91.1%),肌层信号中断灵敏度最好(89.7%).而各叠加征象中则以肠壁索条影+肌层信号中断特异性最高(89.3%),灵敏度最好(78.0%).结论 3.0T MR高分辨成像能较好显示直肠癌局部浸润表现,对术前T分期有一定的临床应用价值.     

PET/CT在小鼠动脉粥样硬化易损斑块筛查中的价值

目的 采用¹⁸F-FDG、¹⁸F-NaF、⁶⁸Ga-DOTA PET/CT对不同月龄动脉粥样硬化（AS）模型小鼠的易损斑块进行显像,探讨3种显像剂检测易损斑块的可行性及临床应用价值。方法 选择高脂喂养ApoE基因敲除小鼠及普通饮食C57BL/6小鼠各18只,采用随机数字表法将其平均分为高脂1组、高脂2组、对照1组和对照2组。高脂1组及对照1组于喂养18周时、高脂2组及对照2组于27周时均行¹⁸F-FDG、¹⁸F-NaF、⁶⁸Ga-DOTA PET/CT检查,显像结束后分别进行游离腹主动脉显像及病理分析。各组测得PET/CT上腹主动脉斑块标准摄取值（SUV_max、SUV_mean）、本底SUV_max、本底SUV_mean及靶本比值（TBR-SUV_max、TBR-SUV_mean）。2组间数据比较采用独立样本t检验;3组间比较采用单因素方差分析,进一步两两比较采用LSD-t检验。结果 高脂1组和高脂2组相比,¹⁸F-FDG显像上,高脂2组的本底SUV_max及SUV_mean高于高脂1组,TBR-SUV_max和TBR-SUV_mean均低于高脂1组（均P<0.05）,2组间¹⁸F-FDG的SUV_max、SUV_mean差异无统计学意义（均P>0.05）;¹⁸F-NaF显像代谢参数均较高,⁶⁸Ga-DOTA 显像代谢参数均较低,但组间差异均无统计学意义（均P>0.05）。高脂组¹⁸F-FDG、¹⁸F-NaF和⁶⁸Ga-DOTA PET/CT代谢参数比较显示,SUV_max、SUV_mean、本底SUV_max及本底SUV_mean的差异均有统计学意义（均P<0.05）,其中¹⁸F-NaF的上述参数均高于¹⁸F-FDG显像,¹⁸F-FDG及¹⁸F-NaF均高于⁶⁸Ga-DOTA（均P<0.05）,但3种显像剂间TBR-SUV_max、TBR-SUV_mean的差异无统计学意义（P>0.05）。结论 ¹⁸F-FDG和¹⁸F-NaF的PET/CT可以识别易损斑块,¹⁸F-NaF较¹⁸F-FDG表现出更高的SUV_max,识别斑块更加敏感,可作为早期甄别易损斑块的可靠的无创性检查手段。     

Proficiency tests in the determination of activity of radionuclides in radiopharmaceutical products measured by nuclear medicine services in 8 years of comparison programmes in Brazil

Proficiency tests were applied to assess the performance of 74 nuclear medicine services in activity measurements of ¹³¹I, ¹²³I, ⁹⁹Tc^m, ⁶⁷Ga and ²⁰¹Tl. These tests produced 913 data sets from comparison programmes promoted by the National Laboratory for Ionizing Radiation Metrology (LNMRI) from 1999 to 2006.

The data were evaluated against acceptance criteria for accuracy and precision and assigned as Acceptable or Not acceptable accordingly. In addition, three other statistical parameters were used as complementary information for performance evaluation which related to normative requirements and to radionuclide calibrators.

The results have shown a necessity to improve quality control procedures and unsatisfactory performances of radionuclide calibrators, which incorporate Geiger–Müller detectors.     

西地那非治疗新生儿持续性肺动脉高压的Meta-分析

 目的 系统评价西地那非治疗新生儿持续性肺动脉高压(PPHN)的有效性和安全性,为临床治疗提供参考依据。方法 计算机检索PubMed、The Cochrane Library、Ovid-Embase、中国期刊全文数据库(CJFD)、万方数据库和中文科技期刊数据库(VIP)、中国生物医学文献数据库(CBM),收集西地那非治疗新生儿PPHN的随机对照试验(RCTs),严格根据纳入排除标准,对纳入文献进行内在偏倚风险评估、资料提取、运用RevMan5.3软件进行数据合并。结果 最终纳入9个RCTs。Meta-分析结果显示:与基础治疗相比,加用西地那非能降低病死率[RR=0.16,95％CI(0.06,0.41), P＜0.01],降低肺动脉压[MD=13.69,95％CI(3.98,23.40), P＜0.01],升高氧分压[MD=6.51,95％CI(5.13,7.89), P＜0.01],降低二氧化碳分压[MD=16.04,95％CI(11.33,20.74), P＜0.01],且差异均有统计学意义;但在升高血氧饱和度[MD=14.34,95％CI(-3.72,32.40),P＞0.01],降低氧合指数[MD=21.43,95％CI(-3.98,46.84), P=0.01]方面,两组差异无统计学意义。结论 西地那非在降低PPHN患儿的病死率和肺动脉压,升高氧分压和降低二氧化碳分压方面具有一定优势,局限于纳入研究数量和随访时间,在缩短其住院时间和机械通气时间等方面尚不明确,且缺乏长期安全性评估结果。     

Biodistribution of 225Ra citrate in mice: retention of daughter radioisotopes in bone

Alpha-particle-emitting radionuclides have potential for therapy of localized disease due to their high linear energy transformation and short pathlengths. Radiometals that home naturally to bone can be exploited for this purpose, and ²²³Ra (t_1/2=11.4 days) recently has been studied for therapy of bone tumors in mice and rats. Actinium-225 (t_1/2=10 days) is also an attractive radioisotope for endoradiotherapy. In a single decay of a ²²⁵Ac nucleus and its subsequent decay daughters, over 27 MeV (90% of total energy) is released by sequential emission of four particles, ranging in energy from 5.7 to 8.4 MeV. Although Ac³⁺ does not home naturally to bone, its parent radioisotope ²²⁵Ra (β⁻, t_1/2=15 days) can be used as an in vivo source for ²²⁵Ac. Thus, injection of ²²⁵Ra takes advantage of the bone-homing properties of radium coupled with the significant amount of energy released from the ²²⁵Ac decay chain. Our data confirm that a large fraction of radium citrate injected intravenously into mice localizes rapidly in bone. Injected doses per gram (ID/g) for ²²⁵Ra range from 25% in skull to about 10% in sternum. Once deposited, the ²²⁵Ra remains in the bone with a biological half life of >40 days. Furthermore, >95% of the daughter radioisotope, ²²⁵Ac, is retained in the bone. However, a significant fraction of one of the daughter radioisotopes, ²¹³Bi, is found in kidney. The biodistribution data indicate that ²²⁵Ra injection should be a powerful agent for killing cells associated with bone; however, the toxicity of this radioisotope which is similar to that of other emitters limits the dose that can be tolerated.     

MSCT 在儿童卵巢扭转中的诊断价值

目的 探究多层螺旋CT（MSCT）检查在儿童卵巢扭转诊断中的应用价值。 方法 回顾性分析2014年1月至2018年6月于天津市儿童医院经术后免疫组织化学检查确诊为卵巢扭转的30例女患儿的临床资料与影像资料,年龄2~12岁,中位年龄9.3岁。所有患儿均于术前行腹部MSCT检查,主要观察卵巢扭转后的大小、形态、密度以及子宫附件是否发生异常变化。术后行免疫组织化学检查。 结果 30例卵巢扭转患儿中,发生于右侧者22例（73.3%,22/30）、左侧者8例（26.7%,8/30）;9例（30.0%,9/30）证实为单纯性卵巢扭转、21例（70.0%,21/30）合并占位性病变。MSCT检查结果显示,27例（90.0%,27/30）患侧卵巢均有不同程度肿大伴密度增高,8例（26.7%,8/30）伴有钙化,13例（43.3%,13/30）显示卵巢周边蜂窝状改变的增大滤泡,12例（40.0%,12/30）出现周围脂肪间隙模糊,20例（66.7%,20/30）子宫不同程度向患侧卵巢移位,23例（76.7%,23/30）伴有盆腔少量积液。 结论 MSCT可作为儿童卵巢扭转的重要辅助诊断手段,有助于提高卵巢扭转的检出率,为临床治疗提供参考依据。     

Distribution of radiocesium and natural gamma emitters in pine needles in coniferious forest sites of Izmir

Using a high-resolution gamma-spectrometer system, the activity concentrations of ⁷Be, ¹³⁷Cs, ⁴⁰K and ²²⁶Ra were determined in the pine needles. Activity concentrations of the concerned radionuclides in the needle samples were as follows: ⁷Be, 24.6±2.40 to 210±7.21 Bq kg⁻¹, ⁴⁰K, 23.5±12.4 to 287±15.6 Bq kg⁻¹, ²²⁶Ra, 0.44±0.12 to 12.3±2.18 Bq kg⁻¹, and ¹³⁷Cs, 0.61±0.30 to 2.29±0.38 Bq kg⁻¹. It is found that the frequency distributions obtained for ⁷Be and ¹³⁷Cs can be fitted to a normal distribution, and for ⁴⁰K and ²²⁶Ra can be fitted to a log-normal distribution.     

不同强度运动时大鼠骨骼肌能量代谢产物的变化

本研究旨在观察不同强度运动时 ,与能量代谢有关的骨骼肌腺嘌呤核苷酸 (ATP)、磷酸肌酸 (CP)、乳酸 (LA)和呼吸链氧化还原的变化特点 ,以进一步阐明训练中运动强度这一重要因素的生理意义。雄性SD大鼠先经 5周耐力训练筛选 ,再进行 3周递增速度训练。正式实验时 ,随机分成 6个强度组 (0m/min、18m/min、30m/min、4 2m/min、5 4m/min、6 6m/min) ,6只 /组 ,每组以 6m/min的增幅进行 3分钟准备活动 (0m/min组为安静时处死 ) ,然后以预定强度跑 3分钟后立即处死 ,取右腿用液氮固定 ,凿取腓肠肌 ,经冷冻干燥后制备肌肉提取液。用高效液相法测定肌肉ATP、ADP、AMP、CP、NADH和NAD+ ,用紫外分光法检测肌乳酸。结果表明 ,随着运动强度的增加 ,运动后即刻大鼠腓肠肌能量代谢产物的变化如下 :(1)ATP浓度在 18～ 4 2m/min范围内呈下降趋势 ,超过 4 2m/min出现上升趋势 ,其中 ,4 2m/min组比安静组降低 (P <0 0 1) ,5 4m/min组较 4 2m/min组升高 (P <0 0 5 ) ;ADP和AMP的变化表现为波动性上升的趋势 ;CP浓度、能荷 (EC)以及ATP/ADP的比值呈波动性下降趋势 ;同时 ,随着ATP/ADP比值的下降 ,AMP的生成增加 ,CP逐渐降解。(2 )肌乳酸、NADH和NADH/NAD+ 比值呈波动性上升趋势 ,当强度大于 4 2m/min时NADH/NAD+明显上升 ,     

Value of air trapping in detection of small airways disease in smokers

Purpose: 
To test the hypothesis that diffuse and/or focal air trapping are sensitive indicators of airflow obstruction in smoker's small airways disease, when age, gender and presence of emphysematous lesions were allowed for. Material and Methods: 
Fifty-eight smokers and 34 never smokers, recruited from a randomized population study of men born in 1933, were investigated by HRCT and by extended pulmonary function tests, including a sensitive test for small airways disease (N₂ slope). Diffuse air trapping was evaluated by calculating a quotient of mean lung density at expiration and inspiration. Focal air trapping was scored visually by consensus. Results: 
Diffuse air trapping did not differ between non-emphysematous smokers and never smokers. Furthermore, diffuse air trapping correlated well to the quotient between the residual volume and total lung capacity (RV/TLC, p = 0.01) and was consequently higher in emphysematous smokers than in never smokers.
Focal air trapping was found as frequently in smokers without emphysema as in never smokers. Smokers with emphysema showed significantly less focal air trapping. Neither the N₂ slope nor any of the other lung function variables differed between those with and without focal air trapping among non-emphysematous smokers. Conclusion: 
Neither diffuse nor focal air trapping are sensitive indicators of smoker's small airways disease.     

贵州省部分矿山放射性水平的评价

目的 调查和评价贵州省铝、锰、锑、磷、汞等部分矿山放射性水平。方法 对矿区氡气、钍气浓度进行累积1年的现场检测;采集矿石、矿山周围土壤进行放射性核素分析;对矿区γ辐射水平进行测量;对矿山渗透水进行总α、总β测量。结果 某铝矿山春、夏两季井下氡浓度水平为626.0～3866 Bq m³,秋、冬两季为38.9～655.0 Bq m³,全年平均值为1374 Bq m³;春、夏两季井下钍浓度水平为626.0～4834 Bq m³,秋、冬两季为40.9～344.0 Bq m³,全年平均值为1221 Bq m³。其余矿山均低于此水平。矿石放射性核素²²⁶Ra为6.9～511.9 Bq/kg、²³²Th为1.4～536.7 Bq/kg、⁴⁰K为<17.5～433.7 Bq/kg。γ外照射最高的为铝矿,平均值(87.0±8.1)×10^-8 Gy/h,最低的为锑矿,平均值(6.0±1.9)×10^-8 Gy/h。矿山井下水总α为小于探测下限～17.5(×10^-2Bq/L),总β为小于探测下限～37.4(×10^-2Bq/L)。结论 此次调查的部分矿山,大多采用机械和自然相结合的通风方式,通风情况较好。但铝矿井下的氡、钍浓度水平明显高于井外,全年平均值分别是井外的78倍和15倍;铝矿的γ外照射平均值(87.0±8.1)×10^-8 Gy/h,也明显高于贵州省γ天然辐射平均值(13.3×10^-8 Gy/h)。这将对该矿的矿工增加一定的附加剂量。     

Change in signal intensity on MRI of fat in the head of markedly emaciated patients

The amount of fat in various parts of the body decreases in emaciated patients, but responds differently to disease processes. The order of disappearance of fat in various parts of the head has rarely been studied with MRI. We imaged ten patients with anorexia nervosa and one cachectic patient with a psychiatric disorder with a 1.5 T imager. Signal intensities of bone marrow of the skull, subcutaneous tissue, and orbits were assessed on T1- and T2-weighted images, and correlated with the body mass index (BMI) and haemoglobin concentration (Hb). On T1-weighted images, five patients (BMI 15.6-17.8 kg/m2, mean 16.6 kg/m2; Hb 10.1-14.2 g/dl, mean 13.8 g/dl) showed the normal pattern of fat. One (BMI 13.6 kg/m2, Hb 10.4 g/dl) lost the high signal of bone marrow, but high signal of subcutaneous tissue and the orbits was preserved. High signal from bone marrow and subcutaneous tissue disappeared in three patients (BMI 11.5-13.5 kg/m2, mean 12.5 kg/m2; Hb 7.9-9.7 g/dl, mean 8.7 g/dl), but orbital high signal was preserved. The remaining two patients (BMI 9.3 and 13.5 kg/m2, mean 11.5 kg/m2; Hb 7.6 and 8.9 g/dl, mean 8.3 g/dl) showed complete loss of high signal from fat in the head. The order of disappearance of fat (bone marrow, subcutaneous fat, then orbits) correlated with both BMI and Hb. Atrophy of bone marrow was demonstrated on T2-weighted images in five patients with BMI 13.5 kg/m2 or less, and Hb 9.7 g/dl or less.