CORDIC算法在B超数字扫描变换器中的应用

数字扫描变换器在B型超声诊断仪的应用，能使现代实时B型超声诊断仪实现一些新的诸如图像冻结、多帧贮存、数据测量计算和TV显示等功能。在设计B型超声诊断仪中数字扫描变化器的过程中，直角坐标到极坐标变换是一个关键的技术，本研究论述了应用在数字扫描变化器中的一种新的算法——CORDIC算法，对该算法的原理进行了简介，将CORDIC算法应用到直角——极坐标变换中，并进行了算法修正和公式计算。根据其具体的应用对该算法进行了优化，并给出了算法的硬件实现结构。最后，对算法进行了软件仿真，并给出了结果分析。     

医学显微图像分割方法研究进展

医学显微图像分割是医学图像处理中的一个经典难题.针对近年来出现的新方法、新理论,对各种分割方法进行了系统论述,主要包括基于数学形态学方法、神经网络分割、模糊分割、小波分析、遗传算法、统计方法和基于特定模型等方法的图像分割.由于显微图像的复杂性,采用单一方法很难准确分割,故对混合方法也作了一定论述.文中还简要讨论了各种方法的特点和局限性.同时对分割的评价体系也做了简要论述.     

The clinical radiological and histological correlation of orbital assessment in malignant lesions of the maxillo-ethmoid complex

Twelve patients undergoing surgery between May 1995 and March 1999 for malignant tumours of the paranasal sinuses abutting or invading the orbital walls were studied for the need to remove orbital contents. Alt patients were evaluated clinically, radiologically (CT Scan) and per-operatively to delineate the extent of orbital invasion. Combined regimen (Surgery + Radiotherapy) were used in all patients. A biopsy from periorbita was taken when eye was spared. It was found that per-operative evaluation of the orbit is equally specific in comparision to clinical and CT Scan combined and eye may be preserved in selected patients with involvement of orbital periosteum provided there is no frank soft tissue mass in the orbit.     

肝脏螺旋CT多期扫描中造影剂的应用

目的:研究肝脏螺旋CT多期扫描中造影剂的不同注射速度对正常肝脏强化的影响,选择最佳的多期扫描延迟时间.方法:正常肝脏60例随机分为3组,先进行全肝平扫,然后以不同速度(2,3及4s)从肘静脉注入60%泛影葡胺100ml后15s,选择第一肝门层面开始扫描,以后每隔5s在同一层面扫描一次,共扫描3min.分别测量各组腹主动脉、门静脉和肝实质增强前、后不同时间的CT值,其中腹主动脉选取中心部位测量,门静脉选取门静脉主干中心部位测量,肝实质则选三个点(左叶一点,右叶前、后段各一点),然后取平均值.观察3组增强效果并进行统计学比较.结果:各组主动脉、门静脉和肝实质增强效果以3ml/s与4ml/s组为优,4ml/s组略高于3ml/s组,统计学处理两者间无显著性差异(P＞0.05),而与2ml/s组比较均有显著性差异(P＜0.01).2ml/s组主动脉、门静脉及肝实质到达峰值的时间分别为45,70,70,120s开始进入平衡期;3ml/s和4ml/s组均为21,62,62,120s开始进入平衡期.结论:在造影剂总量相同时,适合肝脏螺旋CT多期扫描的造影剂注射速度是3ml/s;最佳的肝脏螺旋CT多期扫描延迟时间为动脉期20s,门静脉期60s,平衡期180s.     

Bone scan of hemodialysis patients with secondary hyperparathyroidism before and after parathyroidectomy

Renal osteodystrophy (ROD) accompanied by long-term hemodialysis patients with chronic renal failure includes several forms of disorders of mineral and skeletal metabolism such as osteitis fibrosa attributed to secondary hyperparathyroidism, osteomalasia and adynamic bone disease. Bone scan is performed to detect of the mainly pathophysiology of ROD. We investigated bone scan of 25 hemodialysis patients with secondary hyperparathyroidism diagnosed clinically before and after parathyroidectomy (PTX). Before PTX an diffusely high accumulation of bone seeking agent in the whole skeleton especially skull in all patients (100%), vertebra in 24 out of 25 (96%), patella in 24/25 (96%), limbs in 23/25 (92%), sternum in 19/25 (76%), sacrum in 18/25 (72%) and costochondral junctions in 14/25 (56%) was noted in these patients. The radionuclide activity of the calvaria, maxilla and mandible in the skull was prominently high. Fourteen patients had an equally high activity in the calvaria, maxilla and mandible, 6 patients had higher activity in the maxilla and mandible than that of calvaria and 5 patients had higher in the calvaria than that of maxilla and mandible. After PTX the changes in the skull were obvious in 19 patients who showed a more markedly decreased in activity of the maxilla and mandible than that of the calvaria. In 3 patients showed a more markedly decreased in activity of the calvaria than that of the maxilla and mandible. Another 3 demonstrated equally decreased in activity in the calvaria, maxilla and mandible. It became clear that the highest activity of the skull was shown in all patients and the therapeutic changes of the skull are the most pronounced in maxilla and mandible in this study.     

Selective incorporation of111In-labeled PHOTOFRIN™ by glioma tissuein vivo

The use of PHOTOFRIN for photodynamic therapy of human gliomas has been studied by i.v. administration and laser photosensitization. Defining the uptake of PHOTOFRIN in the patient's tumor in comparison with the surrounding normal brain tissue is highly desirable for patient selection and study ofin vivo kinetics. We utilized a non-invasive approach to the detection of PHOTOFRIN uptake in brain tumors with¹¹¹In-oxine radiolabeled PHOTOFRIN and external imaging and quantitation using a gamma camera. Biodistribution of¹¹¹In-labeled PHOTOFRIN in 13 organs was determined in four dogs and 15 mice with gliomas.^99mTc-DTPA was used as a control for nonspecific uptake. The greatest concentration of¹¹¹In-PHOTOFRIN in the brain tumor occurred at 24 hours post i.v. administration. The brain tumor PHOTOFRIN uptake was seven times greater than that of normal brain. The decreased blood background at 72 hours made this the optimum time for imaging. Specific tumor tissue uptake of¹¹¹In-PHOTOFRIN occurred, well beyond that resulting from blood-brain-barrier (BBB) breakdown.     

胸部CT在矽肺诊断中的意义

目的　评价胸部ＣＴ 检查在矽肺临床诊治过程中的应用价值。方法　对５８ 名长期接触矽尘的工人进行临床、Ｘ 射线平片、胸部ＣＴ 等检查, 该组病人平均年龄（５９ ±２） 岁, 平均接尘工龄２９ 年。结果　两种方法在大多数情况下其结果是类似的, 但对早期矽肺的诊断ＣＴ 片并不优于普通Ｘ 射线平片, 在８ 例经ＣＴ 检查诊断为０ ＋ 的病例中有２名Ｘ 射线平片检查诊断为矽肺Ⅰ期; 而对融合团块的发现, ＣＴ 检查要较Ｘ 射线平片检查敏感, 在经ＣＴ 检查发现的２７例有融合团块的复杂矽肺病例中, Ｘ 射线平片检查只发现２２ 例。另外对于矽肺合并症的诊断ＣＴ 检查对临床也很有帮助, 在合并肺癌的７ 例病人中, 均属经ＣＴ 检查证实, 在合并肺结核的１３ 例病人中也有９ 例经ＣＴ 检查证实。结论　胸部ＣＴ 与Ｘ 射线平片比较虽然不能发现更多的早期病例, 但能较早地发现团块融合改变, 此外对肺结核及肺癌等合并症的发现也很有价值。     

The association between radiological spreading pattern and clinical outcomes in necrotizing external otitis

ObjectivesNecrotizing external otitis (NEO) is a rare infectious disease of the skull base. The purpose of this study was to determine whether clinical outcomes of NEO can be correlated to different infectious spread patterns.MethodsRetrospective chart review from 2010 to 2019 with NEO patients, who were divided into two cohorts: single spreading patterns (group A) or complex spreading patterns (group B) as diagnosed by CT. Clinical symptoms, diagnostic and treatment delay, course of disease, complications, and duration of antibiotic exposure were retrospectively collected from patient records.Results41 NEO patients were included, of which 27 patients belonged to group A (66%). The disease-related mortality rate was 12.2% among the entire cohort, no differences were found between group A and B. Higher rates of N.VII (42.9% vs 14.8% P = 0.047) and N. IX palsies were found in group B compared to group A (28.6% vs 3.7%, P = 0.039). The median duration of antibiotic use was significantly different for a complex spreading pattern, clinical recovery and hospitalizations. Complications were associated with higher diagnostic delay and with a complex spread pattern. The median duration of follow-up was 12.0 (IQR 6.0–19.5) months.ConclusionNEO is a severe disease, with significant mortality and morbidity (cranial nerve palsies). The radiological spread pattern may assist in predicting clinical outcome. Furthermore, complex spread patterns are associated with higher rates of clinical nerve palsies (N. VII and N.IX), complications, surgery rates and longer duration of antibiotic use. Diagnostic delay was associated with mortality, complications and facial palsies.Level of evidenceLevel IV.     

肝海绵状血管瘤的螺旋CT表现特征

目的：分析肝海绵状血管瘤的螺旋ＣＴ表现特点,探讨应用螺旋双期或三期增强扫描鉴别肝内实性占位灶的价值。方法：对４８ 例患者ＣＴ平扫发现肝内占位病灶后采用螺旋ＣＴ增强扫描。造影剂单相注射,每秒３～３．５ ｍ ｌ,每例５０～８０ ｍ ｌ。第一相全肝螺旋增强扫描在造影剂注入后２０～２５ ｓ开始,第二相６０～７０ ｓ,延迟５～１５ｍ ｉｎ 对病灶所在的层面进行扫描。结果：５８ 个病灶平扫均为境界清楚的低密度区,增强后４３ 例（８９．５８％ ）于动脉期出现病灶边缘部致密的结节状或斑块状强化,门静脉期扫描增强区域扩大或整个结节增强。延迟扫描病灶全部强化或绝大部分强化,密度与肝实质相等或稍高。３ 例（６．２６％ ）动脉期表现为致密强化结节影（直径＜ ２ｃｍ ）, 门静脉期结节密度变淡,延迟扫描病变与肝脏等密度。２ 例（４．１６％ ）动脉期未见病灶强化,门静脉期病灶稍小,延迟扫描病变呈等密度灶。结论：肝海绵状血管瘤的特征表现是增强早期病灶边缘区的结节状致密强化,与肝癌的鉴别之处在于延迟相病灶表现为相等或稍高密度