正常耳颞骨内面神经形态分析

目的　借助CT分析正常耳颞骨内面神经的形态特点。方法　选取50例正常耳,其中男33耳,女17耳。通过颞骨CT多平面重组技术显示各段面神经骨管,测量相关数据 并统计分析不同性别及侧别下有无差异。结果　正常耳面神经管迷路段长度（3.64±0.70）mm、宽度（0.90±0.12）mm;鼓室段长度（11.74±1.71）mm、宽度（0.90±0.17）mm;乳突段长度（12.69±1.96）mm、宽度（1.12±0.20）mm。第一膝和第二膝的角度分别为（70.12±13.81）°和（109.43±10.81）°。结论　正常耳面神经在颞骨内走行稳定,不存在侧别和性别差异。     

Do various imaging modalities provide potential early detection and diagnosis of medication-related osteonecrosis of the jaw? A review

Objective:Patients with medication-related osteonecrosis of the jaw (MRONJ) often visit their dentists at advanced stages and subsequently require treatments that greatly affect quality of life. Currently, no clear diagnostic criteria exist to assess MRONJ, and the definitive diagnosis solely relies on clinical bone exposure. This ambiguity leads to a diagnostic delay, complications, and unnecessary burden. This article aims to identify imaging modalities’ usage and findings of MRONJ to provide possible approaches for early detection.Methods:Literature searches were conducted using PubMed, Web of Science, Scopus, and Cochrane Library to review all diagnostic imaging modalities for MRONJ.Results:Panoramic radiography offers a fundamental understanding of the lesions. Imaging findings were comparable between non-exposed and exposed MRONJ, showing osteolysis, osteosclerosis, and thickened lamina dura. Mandibular cortex index Class II could be a potential early MRONJ indicator. While three-dimensional modalities, CT and CBCT, were able to show more features unique to MRONJ such as a solid type periosteal reaction, buccal predominance of cortical perforation, and bone-within-bone appearance. MRI signal intensities of vital bones are hypointense on T₁WI and hyperintense on T₂WI and STIR when necrotic bone shows hypointensity on all T₁WI, T₂WI, and STIR. Functional imaging is the most sensitive method but is usually performed in metastasis detection rather than being a diagnostic tool for early MRONJ.Conclusion:Currently, MRONJ-specific imaging features cannot be firmly established. However, the current data are valuable as it may lead to a more efficient diagnostic procedure along with a more suitable selection of imaging modalities.     

Preformulation studies of Zidovudine derivatives: Acid dissociation constants, differential scanning calorimetry, thermogravimetry, x-ray powder diffractometry and aqueous stability studies

As part as of the preformulation studies of new 5'-OH derivatives of zidovudine, compounds 2-6, their acid dissociation constants, Differential Scanning Calorimetry (DSC) and Thermogravimetry (TG) curves, X-Ray Powder diffractograms and aqueous stability are reported. A sensitive technique such as differential scanning potentiometry was used to determine the pKa constants of the above mentioned compounds. In addition, pKa values were calculated from theoretical methods, and no significant differences with those of experimental ones were observed. X-Ray Powder Diffractometry data demonstrated that compounds 2-4 were crystalline while 5 and 6 were amorphous. DSC analysis indicated that all of them presented an exothermic decomposition peak above 150 °C which is accompanied by a weight loss in the respective TG curves. The stability of these compounds in aqueous medium at different pH values was investigated, using a validated High Performance Liquid Chromatography (HPLC) method, which demonstrated to be rapid, selective, sensitive, accurate and stability-indicating. Good recovery, linearity and precision were also achieved. For all compounds the aqueous hydrolysis followed a pseudo-first-order kinetics, depending on pH and the union existing between AZT and the associate moiety. The hydrolysis was catalyzed by hydroxide ion in the 7.4-13.2 pH range, while all compounds exhibited pH-independent stability from acidic to neutral media (pHs 1.0-7.4).     

胼胝体梗死的临床与影像学分析

目的 探讨胼胝体梗死患者的临床和影像学特点.方法 收集符合脑梗死诊断的416例患者的临床资料,其中8例经过MRI证实为胼胝体梗死.结果 胼胝体梗死占全部脑梗死患者的1.9%.7例CT扫描未显示胼胝体梗死,经非增强MRI检查显示病灶,另1例经增强MRI检查显示病灶.梗死灶可仅累及胼胝体(膝部、体部或压部),也可合并额叶、...     

自动管电流模式在头颈部动脉CT造影使用低剂量射线的可行性

目的在不影响显像质量的前提下,探讨应用自动管电流模式在256层螺旋CT头颈部动脉造影中降低射线剂量的可行性。方法对60例怀疑头颈部动脉疾病的患者进行头颈部动脉CT造影显像。患者被分为两组,即常规管电流扫描组(A组)和自动管电流扫描组(B组),每组30例。A组采用250 mAs管电流扫描,B组采用自动管电流扫描。对两组图像信号噪声比、对比度噪声比和有效剂量进行评估。结果 A,B两组图像信号噪声比分别为(37.47±9.39)和(36.85±7.96),无统计学差异(P=0.79)。两组图像对比度噪声比分别为(32.13±9.06)和(31.86±7.66),无统计学差异(P=0.90)。A组的CT容积剂量指数固定无变化,均为16.5mGy,B组为(10.55±0.94)mGy,差异有统计学意义(P0.001)。射线剂量降低约36.1%。结论与常规管电流比较,自动管电流模式头颈部动脉CT造影在不降低图像质量的情况下,射线剂量明显降低。提示该方法使用低剂量是可行的。     

腭咽成形术后上气道形态改变与远期疗效的关系

目的探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者腭咽成形术(UPPP)后上气道形态学变化及其与远期疗效的关系。方法 21例经多导睡眠监测(PSG)确诊为中重度OSAHS患者均行UPPP,术前行上气道CT检查,术后随访17～34个月,复查上气道CT及PSG,比较手术前、后CT指标的变化及其与PSG参数变化值的相关性。结果术后患者上气道形态学改变主要表现在腭咽区左右径、最小截面积增大,舌后区前后径减小;术前近似圆形或纵向椭圆形的咽腔,术后呈横向椭圆形;有效组呼吸暂停低通气指数(AHI)的改变量与软腭后区左右径及截面积的改变量呈负相关(R2=-0.560,P=0.037;R2=-0.645,P=0.016)。结论 UPPP疗效可能与软腭后区左右径及截面积的增大和气道形状的改变相关。     

第2骶椎骶髂螺钉最佳进钉通道的分析

目的　利用数字化仿真技术确定并测量第二骶椎骶髂螺钉最佳进钉通道参数。 方法　将2011年4月至2011年7月入院的8例无骨盆病变患者（男性4例,女性4例,年龄25~53岁）的CT数据集导入Mimics10.01进行三维重建,利用数字化仿真技术生成骶椎阴模,利用透视骶椎阴模确定S2骶髂螺钉最佳进钉通道,利用空间解析几何测量相关参数。 结果　8例共16侧资料的S2骶髂螺钉最佳进钉通道均能以此方法确定。最佳进钉通道参数：最大半径男性为（6.38±0.54）mm,女性为（4.9±0.74）mm;深度男性为（68.93±3.49）mm,女性为（58.43±8.16）mm;与矢状面夹角男性为（73.48±8.57）°,女性为（79.93±　5.29）°;与横截面夹角男性为（14.07±6.22）°,女性为（6.95±4.81）°;与冠状面夹角男性为（7.12±7.11）°,女性为（5.87±5.01）°。最佳进钉点及最佳进钉终点的确定方法为：在骨盆出口位X线透视图像上,作一边长分别水平及垂直并恰好包围骨盆的矩形,以左下角顶点为原点,左上角顶点为（0,1）,右下角顶点为（1,0）建立二维直角坐标系,进钉点坐标男性为（0.5±0.26,0.52±0.04）,女性为（0.49±0.24,0.47±0.10）;进钉终点坐标男性为（0.5±0.01,0.59±0.07）,女性为（0.5±0.02,0.49±0.14）。在骨盆入口位X线透视图像上,用相同的方法作一矩形并定义坐标系,进钉点坐标男性为（0.5±0.26,0.52±0.04）,女性为（0.49±0.24,0.47±0.10）,进钉终点坐标男性为（0.5±0.01,0.78±0.01）,女性为（0.5±0.02,0.81±0.03）。S2骶髂螺钉最佳进钉通道参数男女对比“最大半径”、“深度”、“与横截面夹角”、“进钉点前后相对位置”有统计学差异（P<0.05）,余无统计学差异。 结论　数字化仿真技术能精确确定S2骶髂螺钉最佳进钉通道参数。     

椎动脉扭曲与后循环缺血的相关性

目的：探讨椎动脉扭曲与后循环缺血(posterior circulation ischemia, PCI)的相关性。方法纳入年龄≥50岁的 PCI 患者和同期无脑缺血表现的对照者。所有患者均行 CT 血管造影,观察颈部椎动脉扭曲情况并进行评级,分析影响 PCI 的相关危险因素。结果共纳入112例PCI 患者和90例对照者。单变量分析显示,PCI 组高血压(80．36%对54．44%;χ2=15．613,P <0．001)、吸烟(35．71%对18．89%;χ2=6．974,P =0．008)、饮酒(25．89%对10．00%;χ2=8．253,P =0．004)、后循环血管狭窄(54．46%对24．44%;χ2=18．578,P <0．001)和椎动脉扭曲(71．43%对48．89%;χ2=10．695, P =0．001)的患者比例以及总胆固醇[(4．96±1．26)mmol/L 对(4．61±1．04)mmol/L;t =-2．110, P =0．036]、低密度脂蛋白胆固醇[(3．02±0．90)mmol/L 对(2．69±0．78)mmol/L;t =-2．671,P =0．008]和纤维蛋白原[(3．67±1．69)mg/L 对(3．25±0．97)mg/L;t =-2．002,P =0．047]水平均显著高于对照组。 PCI 组双侧椎动脉均扭曲的比例显著高于对照组(30．36%对12．22%;χ2=9．478,P =0．002)。 PCI 组3级椎动脉扭曲的比例显著高于对照组(43．75%对26．67%;χ2=6．310,P =0．012)。多变量 logistic 回归分析显示,吸烟[优势比(odds ratio, OR)2．339,95%可信区间(confidence interval, CI)1．037~5．278;P =0．041]、低密度脂蛋白胆固醇(OR 1．580,95% CI 1．050~2．377;P =0．028)、高血压(OR 2．631,95% CI 1．237~5．596;P =0．012)、后循环血管狭窄(OR 3．419,95% CI 1．638~7．134;P =0．001)和椎动脉扭曲(OR 2．413,95% CI 1．212~4．803;P =0．012)是 PCI 的独立危险因素。结论椎动脉扭曲是中老年 PCI 的独立危险因素。     

医用移动式X射线机床旁操作辐射水平调查

目的 检测不同类型医用移动式X射线机在床旁操作时机架不同角度和设备不同距离处的周围辐射剂量率,为管理部门采取有针对性的干预措施提供理论依据。方法 上海市徐汇区三级、二级和一级医疗机构,各抽取一定比例的医用移动式X射线机共20台,采用美国FLUKE公司451P-DE-SI-RYR型X、γ辐射监测仪现场直读检测,在常规开机工作条件下,在距离机头的不同距离(1、2、3、5 m)和不同角度(0°、72°、144°、216°、288°)处,对设备周围辐射剂量率进行检测和分析。结果 床旁操作使用的医用移动式X射线机的成像类别以CR为主,占80%;曝光开关多采用遥控方式,达75%,但仍有25%的设备采用手控操作。对医用移动式X射线机操作时周围辐射剂量率的检测结果表明,设备不同角度对X射线剂量率的检测结果无明显影响,但随着布点距离的增加,X射线剂量率明显下降。在距离设备1、2、3、5 m处,X射线剂量率范围分别在1000~2000 μSv/h、300~500 μSv/h、40~300 μSv/h和10~40 μSv/h。结论 对于医用移动式X射线机操作,机头不同距离处的X射线剂量率有明显差异,建议安全距离应设置在5 m以外,并采用适当的铅屏风等屏蔽设施,以保护放射工作人员和周围公众的健康与安全。     

X射线生物辐照仪剂量学探讨

目的 探讨X射线生物辐照仪的射野剂量和周围环境辐射剂量。方法 用PTW UNIDOS电离室剂量仪测量X射线生物辐照仪正常工作状态时有效射野80%范围内的多对对称点的剂量,测量射野中心点剂量且每周重复测量一次;用451P环境剂量巡测仪测量X射线生物辐照仪正常工作状态和停机状态时前面、后面、左边、右边和顶部各方向的周围环境辐射剂量。结果 X射线生物辐照仪剂量输出连续7周测量稳定性< 1%,射野对称性为2%,射野平坦度为9.8%;X射线生物辐照仪正常工作状态的周围环境辐射剂量均值为0.194 μSv,属于本底辐射,最大值为辐照仪前面的0.308 μSv略高于且接近本底辐射最高标准。结论 X射线生物辐照仪正常工作状态时射野剂量输出稳定,射野对称性较好,射野平坦度存在瑕疵;环境辐射剂量除前面接近本底辐射最高标准,其余均属于本底辐射,建议操作者在X射线生物辐照仪出束时,远离辐照仪,尽可能减少接受辐射。