原发性肾上腺皮质腺癌的CT诊断价值

目的分析原发性肾上腺皮质腺癌（ACC）的CT表现及其动态增强特征，以提高其诊断准确性。方法回顾性分析经手术病理证实的ACC11例，术前均经CT平扫、动脉期（30S）和门静脉期（70—80S）扫描，复习CT扫描表现并和手术病理作对照。结果11例ACC中，右侧5例，左侧6例。直径4．1—16．0cm，其中，〈5．0cm者2例，5．0—10．0cm者4例，〉10．0cm5例；肿瘤境界清楚3例，邻近脂肪间隙见条索状异常密度影3例，邻近实质脏器受侵犯5例。肿瘤实质成分平扫、动脉期和门静脉期CT值分别为21．9～46．7HU（平均35．3HU）、30．5～65．8HU（平均47．1HU）和52．6～97．0HU（平均74．2HU）。肿瘤中央坏死形成假囊肿4例，网络状改变6例，实质为主伴小囊变1例；6例网络状改变者动脉期可见显著强化的不规则肿瘤血管：结论ACC具有较明显的形态学和血液动力学特征，动态增强扫描尤其是动脉期扫描有明显的诊断价值。     

A review of the effectiveness of aspartame in helping with weight control

Summary Strategies to reverse the upward trend in obesity rates need to focus on both reducing energy intake and increasing energy expenditure. The provision of low‐ or reduced‐energy‐dense foods is one way of helping people to reduce their energy intake and so enable weight maintenance or weight loss to occur. The use of intense sweeteners as a substitute for sucrose potentially offers one way of helping people to reduce the energy density of their diet without any loss of palatability. This report reviews the evidence for the effect of aspartame on weight loss, weight maintenance and energy intakes in adults and addresses the question of how much energy is compensated for and whether the use of aspartame‐sweetened foods and drinks is an effective way to lose weight. All studies which examined the effect of substituting sugar with either aspartame alone or aspartame in combination with other intense sweeteners on energy intake or bodyweight were identified. Studies which were not randomised controlled trials in healthy adults and which did not measure energy intakes for at least 24 h (for those with energy intakes as an outcome measure) were excluded from the analysis. A minimum of 24‐h energy intake data was set as the cut‐off to ensure that the full extent of any compensatory effects was seen. A total of 16 studies were included in the analysis. Of these 16 studies, 15 had energy intake as an outcome measure. The studies which used soft drinks as the vehicle for aspartame used between 500 and about 2000 ml which is equivalent to about two to six cans or bottles of soft drinks every day. A significant reduction in energy intakes was seen with aspartame compared with all types of control except when aspartame was compared with non‐sucrose controls such as water. The most relevant comparisons are the parallel design studies which compare the effects of aspartame with sucrose. These had an overall effect size of 0.4 standardised difference (SD). This corresponds to a mean reduction of about 10% of energy intake. At an average energy intake of 9.3 MJ/day (average of adult men and women aged 19–50 years) this is a deficit of 0.93 MJ/day (222 kcal/day or 1560 kcal/week), which would be predicted (using an energy value for obese tissue of 7500 kcal/kg) to result in a weight loss of around 0.2 kg/week with a confidence interval 50% either side of this estimate. Information on the extent of compensation was available for 12 of the 15 studies. The weighted average of these figures was 32%. Compensation is likely to vary with a number of factors such as the size of the caloric deficit, the type of food or drink manipulated, and timescale. An estimate of the amount of compensation with soft drinks was calculated from the four studies which used soft drinks only as the vehicle. A weighted average of these figures was 15.5%. A significant reduction in weight was seen. The combined effect figure of 0.2 SD is a conservative figure as it excludes comparisons where the controls gained weight because of their high‐sucrose diet and the long‐term follow‐up data in which the aspartame groups regained less weight than the control group. An effect of 0.2 SD corresponds to about a 3% reduction in bodyweight (2.3 kg for an adult weighing 75 kg). Given the weighted average study length was 12 weeks, this gives an estimated rate of weight loss of around 0.2 kg/week for a 75‐kg adult. The meta‐analyses demonstrate that using foods and drinks sweetened with aspartame instead of sucrose results in a significant reduction in both energy intakes and bodyweight. Meta‐analyses both of energy intake and of weight loss produced an estimated rate of weight loss of about 0.2 kg/week. This close agreement between the figure calculated from reductions in energy intake and actual measures of weight loss gives confidence that this is a true effect. The two meta‐analyses used different sets of studies with widely differing designs and controls. Although this makes comparisons between them difficult, it suggests that the final figure of around 0.2 kg/week is robust and is applicable to the variety of ways aspartame‐containing foods are used by consumers. This review has shown that using foods and drinks sweetened with aspartame instead of those sweetened with sucrose is an effective way to maintain and lose weight without reducing the palatability of the diet. The decrease in energy intakes and the rate of weight loss that can reasonably be achieved is low but meaningful and, on a population basis, more than sufficient to counteract the current average rate of weight gain of around 0.007 kg/week. On an individual basis, it provides a useful adjunct to other weight loss regimes. Some compensation for the substituted energy does occur but this is only about one‐third of the energy replaced and is probably less when using soft drinks sweetened with aspartame. Nevertheless, these compensation values are derived from short‐term studies. More data are needed over the longer term to determine whether a tolerance to the effects is acquired. To achieve the average rate of weight loss seen in these studies of 0.2 kg/week will require around a 220‐kcal (0.93 MJ) deficit per day based on an energy value for obese tissue of 7500 kcal/kg. Assuming the higher rate of compensation (32%), this would require the substitution of around 330 kcal/day (1.4 MJ/day) from sucrose with aspartame (which is equivalent to around 88 g of sucrose). Using the lower estimated rate of compensation for soft drinks alone (15.5%) would require the substitution of about 260 kcal/day (1.1 MJ/day) from sucrose with aspartame. This is equivalent to 70 g of sucrose or about two cans of soft drinks every day.     

64层CT下肢动脉成像技术研究

目的探讨64层CT下肢动脉成像强化质量的对比剂注射方式。方法前瞻性地选择60例疑诊下肢动脉病变的病人,利用64层螺旋CT行下肢动脉CT血管成像。采用不同的扫描和重建参数,应用370mgI/100ml浓度的对比剂100ml团注或采用先70ml的对比剂后50ml的0.9%生理盐水用双筒高压注射器分别以4.0ml/s的注射速度团注入肘静脉,应用对比剂追踪触发扫描方式待腹主动脉CT阈值达120HU时延迟7s开始扫描;利用MIP和VR方式重建CTA图像;对比不同参数和不同对比剂应用方式的CT血管成像图像质量。结果最佳的扫描与重建参数为准直64×0.6mm,螺距1.5,层厚1.0,重建间隔50%;最佳的对比剂应用方式为(浓度为370mgI/100ml)对比剂70ml、生理盐水50ml以4.0ml/s注射速度按先后顺序团注。结论选择合适的准直、螺距以保证适当的扫描速度,选择合适的对比剂浓度、用量和注射速度以保证血管内足够的对比剂峰值浓度及峰值持续时间,此二者是64层CT下肢动脉成像成功的关键。     

鼻咽癌颈静脉孔侵犯的影像学表现及临床分析

[目的]探讨鼻咽癌颈静脉孔侵犯的临床和影像学特征及临床意义。[方法]回顾性分析8例初治和4例复发鼻咽癌伴颈静脉孔侵犯者的临床表现、CT及MRI特征。[结果]12例中,5例表现为Ⅸ￣Ⅺ颅神经均麻痹的颈静脉孔综合征,7例仅表现为Ⅸ颅神经麻痹。12例,有10例合并舌下神经管受累,3例有一侧的胸锁乳突肌及斜方肌萎缩,2例有一侧舌肌萎缩。CT及MRI显示鼻咽癌颈静脉孔侵犯主要有3种途径,分别为:①鼻咽病变通过茎突后间隙直接蔓延(4例,包括1例茎突后间隙复发);②转移淋巴结直接侵犯(4例,其中2例为咽后淋巴结转移,2例为颈动脉鞘淋巴结复发);③颈静脉孔骨性结构直接破坏(4例,其中1例为单纯颈静脉孔复发)。[结论]鼻咽癌可通过直接蔓延、咽后和颈动脉鞘区转移淋巴结侵犯及骨质直接破坏侵犯颈静脉孔,临床上出现Ⅸ￣Ⅺ颅神经一支或多支均麻痹。CT和MRI,尤其是MRI对于病变的诊断、病变范围的确定和放射治疗计划的制定有非常大的作用。     

比较4种影像技术对早期股骨头缺血性坏死的诊断敏感性

目的评价CR,CT,ECT和MRI在早期股骨头缺血性坏死(ANFH)中的诊断价值。方法回顾性分析16例23髋经手术、病理证实为早期(符合国际骨循环研究会(ARCO)分期标准Ⅰ期-Ⅱ期)股骨头缺血性坏死患者的CR,CT,ECT和MRI的影像学特征及其检查结果。结果CR诊断早期ANFH11髋,阳性率为47.8%,CT诊断早期ANFH14髋,阳性率为60.9%,ECT诊断诊断早期ANFH21髋,阳性率为91.3%,MRI诊断早期ANFH22髋,阳性率为95.7%。经统计学处理,X2=19.38,P<0.01,CR,CT,ECT和MRI四者敏感性的差异具有显著性意义。结论对早期股骨头缺血性坏死影像学诊断而言,CR诊断敏感性较低,CT可提供较多的诊断信息,ECT和MRI的敏感性高于CT及CR,MRI可准确地诊断早期股骨头缺血性坏死。     

暴发流行的肺炎衣原体肺炎影像学表现分析

目的研究肺炎衣原体肺炎暴发流行的胸部影像学特征表现。方法对经过痰和咽试子标本,PCR,MIF检测证实的15例暴发流行的肺炎衣原体肺炎住院患者胸部X线和高分辨CT表现进行分析。结果本组暴发流行的肺炎衣原体肺炎患者均有发热,头痛,全身肌肉酸痛,干咳,声音嘶哑,咽痛等症状。肺部呼吸音减低或细湿啰音4例(26.7%),出现明显肺部影像学表现10例(66.7%)。10例暴发流行的肺炎衣原体肺炎常表现为多发或单发以小叶为中心阴影和腺泡状结节影(100%),病变以两中、下肺叶,外、中带分布;以小叶分布的气腔实变和磨玻璃样阴影(分别为100%和40%)和支气管血管束增厚(90%)。无肺门或纵隔淋巴结增大和胸腔积液。结论暴发流行的肺炎衣原体肺炎具有群体发病,临床和影像学表现有相似的特征,早期CT检查更能真实地反映病变大小、多少和分布范围。     

冠状动脉CT和MR血管成像诊断粥样硬化斑块和狭窄的对比研究

目的 探讨不同成分的斑块对管腔狭窄的影响以及CT和MR血管成像（CTA、MRA）诊断不同成分斑块所致狭窄的准确性。方法 30例冠心病患者在2周内行冠状动脉CTA、MRA和冠状动脉造影（CAG）检查。CTA采用16层螺旋CT，MRA采用屏气三维快速稳态平衡进动（FIESTA）技术。CTA上将斑块分为非钙化和钙化斑块，由2名有经验的放射科医师双盲评价这2种斑块在CTA和MRA上引起的显著性狭窄（≥50％）。以CAG为标准，评价CTA和MRA诊断显著性狭窄的准确性和一致性。结果 30例冠心病患者CTA共发现53个斑块，其中有28个非钙化斑块和25个钙化斑块。28个非钙化斑块中，CAG显示非显著性狭窄（〈50％）7个，显著性狭窄（≥50％）21个。CTA和MRA诊断非钙化斑块显著性狭窄的敏感性和特异性分别为85．7％、85．7％和47．6％、71．4％。CTA与CAG一致性好（Kappa值为0．65）。25个钙化斑块中，CAG显示非显著性狭窄19个，显著性狭窄6个。CTA和MRA诊断钙化斑块显著性狭窄的敏感性和特异性分别为83．3％、31．6％和83．3％、73．7％，MRA与CAG一致性较好（Kappa值为0．46）。非钙化和钙化斑块在CAG上发生显著性狭窄的概率有统计学意义（X^2=11．78，P〈0．01）。结论 非钙化斑块和以非钙化成分为主的混合斑块是导致显著性狭窄的主要原因。完全钙化的斑块不引起或仅引起〈50％的狭窄。CTA诊断非钙化斑块引起的显著性狭窄有很好的准确性，而MRA评价严重钙化斑块引起的管腔变化有明显优势。     

输尿管囊肿的X线征象分析

目的总结输尿管囊肿的X线表现,以提高对该病的认识。方法搜集1995年1月至2005年12月间经手术、病理证实的输尿管囊肿18例,回顾性分析其X线表现。结果18例输尿管囊肿中,发生在单侧者16例,双侧2例。15例出现膀胱内边界清晰的充盈缺损,16例显示“光晕征”,12例显示“蛇头征”。结论输尿管囊肿有典型的影像学表现,静脉尿路造影可明确诊断,为手术提供可靠的影像资料。     

血色病肝脏铁过度沉着症1例

1.病例资料：患者，男，48岁。以“乏力、多饮、多尿、多食，伴消瘦4个月，加重1周”入院。既往有乙型肝炎和地中海贫血病史30年，无输血史，无血色病家族史，曾行“脾脏切除”治疗。查体：慢性贫血面容，全身皮肤黄染有散在色素沉着，巩膜黄染，双手肝掌，男性乳房发育；肼右肋下3cm，剑突下5cm，质硬；腹部未触及肿块。     

高分辨率CT对颞部疾病的检查价值

目的：探讨高分辨率CT（HRCT）对颞部疾病的检查价值。方法：对43例颞部疾病患者行常规CT和高分辨率CT（HRCT）检查所获图像对比分析，并讨论HRCT的检查技术和图像后处理。结果：HRCT对病变的显示率及病变引起骨质破坏的程度，病变边缘，轮廓的显示均明显优于常规CT，尤其能清楚显示常规CT难以显示的中耳及内耳的细微结构，结论：高分辨率CT是颞部疾病的首选检查方法，使用高分辨率CT对颞部疾病的检查给临床提供更多，更准确的诊断信息。