浅析Infinia Vc Hawkeye 4日常质量控制及常见故障处理

目的:理解并掌握Infinia Vc Hawkeye 4日常质量控制的方法措施和常见故障的解决办法。方法:用符合美国电气制造商协会(NEMA)标准的自制99mTc点源和厂家配备的X线质控蒸馏水模型,启用核医学每日质量控制(NM Daily QC)程序和X线每日质量控制(X-ray Daily QC)程序,对仪器的能峰、能量分辨率、中心视野(CFOV)积分均匀性等指标进行测试、分析。结果:2012年下半年NM Daily QC结果和X-ray Daily QC结果均符合要求,仪器处于正常工作状态,性能稳定。结论:科学严格的日常质量控制与管理和及时的常见故障分析与处理是提高核医学图像质量和机器开机率的重要保障。     

导航辅助下正颌外科手术患者围手术期护理

目的探讨导航辅助下正颌外科手术患者围手术期的护理。方法对22例导航辅助下正颌外科手术患者围手术期的护理方法进行回顾性分析。结果22例患者牙颌面畸形得到矫正，术后面容改观明显，患者满意出院。结论导航辅助下正颌手术患者术前做好心理护理及术前宣教，术中完善护理配合及加强术中对患者头发、鼻部、眼睛、口唇的护理，术后进行有效心理护理，术后反应护理，做好出院宣教，对于手术的成功及患者术后康复起着重要的作用。     

Normalized gradient fields for nonlinear motion correction of DCE-MRI time series

Dynamic MR image recordings (DCE-MRI) of moving organs using bolus injections create two different types of dynamics in the images: (i) spatial motion artifacts due to patient movements, breathing and physiological pulsations that we want to counteract and (ii) signal intensity changes during contrast agent wash-in and wash-out that we want to preserve. Proper image registration is needed to counteract the motion artifacts and for a reliable assessment of physiological parameters. In this work we present a partial differential equation-based method for deformable multimodal image registration using normalized gradients and the Fourier transform to solve the Euler–Lagrange equations in a multilevel hierarchy. This approach is particularly well suited to handle the motion challenges in DCE-MRI time series, being validated on ten DCE-MRI datasets from the moving kidney. We found that both normalized gradients and mutual information work as high-performing cost functionals for motion correction of this type of data. Furthermore, we demonstrated that normalized gradients have improved performance compared to mutual information as assessed by several performance measures. We conclude that normalized gradients can be a viable alternative to mutual information regarding registration accuracy, and with promising clinical applications to DCE-MRI recordings from moving organs.     

Évaluation et choix des protocoles d’imagerie sur le système de tomographie conique de basse énergie XVI® d’Elekta

PurposeThis work proposes an evaluation of the Elekta XVI^® kilovoltage cone-beam computed tomography imaging system. The average dose delivered for each acquisition protocol proposed by default by the manufacturer was measured with several detectors and compared to theoretical dose values given by Elekta. At the same time, an evaluation of image quality for pelvic protocols correlated to dose measurements in homogeneous and heterogeneous mediums allowed to optimize the use of the XVI^® system.Materials and methodsThe dose was measured for each acquisition protocol (varying filters, FOV and collimations) with four detectors (CT pencil ion chamber, 0.3 and 0.125 cm³ cylindrical ion chambers, radiothermoluminescent dosimeters) in a CTDI phantom. The dose evaluation in a heterogeneous medium was performed in an experimental anthropomorphic phantom simulating a male pelvis. Image quality was assessed with a Catphan^® 600 phantom.ResultsThe average dose measured in a homogeneous medium was about 17 mGy and 25 mGy per acquisition for Pelvis and Prostate protocols and about 17 mGy and 1 mGy for Lung and Head protocols. The study performed with different detectors showed that doses obtained were of the same order of magnitude (± 10%) and agreed with those supplied by the manufacturer. The evaluation of image quality correlated to the average dose measured allowed to optimize the use of XVI^® acquisition protocols. Measurement results in a heterogeneous medium showed a dose decrease by a factor 1.5 for bone and by a factor 2 for titanium.ConclusionThe study showed that theoretical values proposed by the manufacturer could be used to estimate the average dose delivered to the patient by the kV-CBCT imaging system. The analysis of all the results led to the implementation of a procedure allowing to optimize and account for the dose delivered to the patient by the CBCT imaging system and to report it in the patient folder.     

计算机乳腺摄影与常规乳腺摄影的比较研究

目的探讨计算机(CR)乳腺摄影的图像质量和对乳腺病灶的检测能力。方法对在该院检查的在临床上诊断为疑似乳腺癌的30例患者同时进行常规乳腺摄影和CR乳腺摄影,对二者摄影图像质量与病灶检测能力进行比较。结果 CR乳腺摄影的图像质量及对乳腺病灶的检测能力均优于常规乳腺摄影。结论 CR乳腺摄影因其具有大的曝光宽容度和后处理功能,可获得高质量的图像,从而提高了诊断符合率。     

飞利浦DR图像处理计算机工作原理及软件安装

目的:为减少飞利浦DR图像处理计算机停机时间,排除飞利浦DR图像处理计算机的软件故障.方法:通过介绍飞利浦DR图像处理计算机的硬件结构及工作原理,详细描述图像处理流程,讲解软件安装和校准方法,解决安装过程中所遇到的各种问题.结果:通过优化后的安装方法,可以快速排除软件故障.结论:医院医疗仪器维修工程师通过研究技术资料,不断总结经验,可以对大型医疗设备进行维修