MRI and SPECT findings in amyotrophic lateral sclerosis

Summary MRI was performed in 21 patients and single photon emission computed tomography (SPECT) withN-isopropyl-p-¹²³I iodoamphetamine in 16 patients, to visualize upper motor neurone lesions in amyotrophic lateral sclerosis. T2-weighted MRI revealed high signal along the course of the pyramidal tract in the internal capsule and cerebral peduncle in 4 of 21 patients. SPECT images were normal in 4 patients, but uptake was reduced in the cerebral cortex that includes the motor area in 11.     

Human brain atlas: For high-resolution functional and anatomical mapping

We present the new computerized Human Brain Atlas (HBA) for anatomical and functional mapping studies of the human brain. The HBA is based on many high-resolution magnetic resonance images of normal subjects and provides continuous updating of the mean shape and position of anatomical structures of the human brain. The structures are transformable by linear and nonlinear global and local transformations applied anywhere in 3-D pictures to fit the anatomical structures of individual brains, which, by reformatting, are transformed into a high-resolution standard anatomical format. The power of the HBA to reduce anatomical variations was evaluated on a randomized selection of anatomical landmarks in brains of 27 young normal male volunteers who were different from those on whom the standard brain was selected. The HBA, even when based only on standard brain surface and central structures, reduced interindividual anatomical variance to the level of the variance in structure position between the right and left hemisphere in individual brains. © 1994 Wiley-Liss, Inc.     

造影剂到达腹主动脉的峰值大小与患者因素的关系

目的探讨造影剂到达腹主动脉的峰值大小与患者因素之间的关系。方法108例患者以2.5ml/s注射欧乃派克(300mgI/ml)20ml,12s后采用testbolus技术在腹腔干水平同层动态扫描腹主动脉,用dynamic evaluation软件测得腹主动脉的峰值大小,采用单因素回归分析和多因素逐步回归分析法研究患者的性别、年龄、身高、体重、心率、血压、注射位点、达峰时间及是否有心脏病、糖尿病、或化疗史对造影剂到达腹主动脉峰值大小是否有影响及影响程度。结果造影剂到达腹主动脉峰值大小,在男性平均比女性低;其随年龄、身高、体重、达峰时间的增加而逐渐降低,注射位点在手背静脉其值平均比在肘部静脉低;其不受心率、血压、是否有心脏病、糖尿病或化疗史的影响。参考公式:峰值大小(HU)=383.8400-身高(cm)×1.0909-体重(kg)×0.6760 注射位点×16.7878-达峰时间(s)×1.6882。结论可根据患者的性别、年龄、身高、体重、注射位点和达峰时间来适当调整患者CT血管成像时造影剂用量。     

颅脑外伤性病变的CT检查及其临床意义

目的：探讨颅脑外伤严重程度及CT征象与预后的关系，并探讨CT复查的最佳时间及临床意义。方法：回顾性分析80例颅脑外伤的严重程度与初次CT征象的关系，统计分析复查CT发现新病变的数目、程度及时间。结果：颅脑外伤的严重程度与初次CT征象符合率为92．5％(74／80)。外伤后即刻昏迷、CT显示重度复合伤、脑干损伤或弥漫性脑白质损伤的病死率达70．0％(21／30)。1～3d复查CT发现迟发性病变80个，4—7d21个，7d后8个。结论：临床病情与CT征象变化对判断预后有重要意义，颅脑外伤后3、7d是复查CT的最佳时机，出现病情变化应随时复查。     

老年认知功能障碍与脑结构CT测量的相关性研究

目的探讨脑萎缩与老年认知功能障碍之间的相关性。方法对开滦集团公司1063名离退休职工进行健康查体,用简易精神状态量表(MMSE)评定认知功能,按分界值将本次研究对象分为认知功能障碍组和认知功能正常组,同时用CT线性测量脑的相关部位以诊断脑萎缩情况,并对各型脑萎缩与认知功能的相关系数及提示老年认知功能障碍的敏感度、特异度、准确度进行分析。结果1063名观察对象中符合入选标准并资料完整者共计511名,其中108名有认知功能障碍,髓质脑萎缩55名、皮质萎缩5名、混合型萎缩30名;认知功能正常者403名,髓质脑萎缩214名、皮质萎缩13名、混合型萎缩62名。认知功能障碍组脑萎缩的发病率高于认知功能正常组,差异具有统计学意义(P<0.005);2组间颞叶海马钩回间距(26.86mm±3.73mmvs25.95mm±3.80mm)及海马钩回间距/大脑左右径的比值(0.21±0.02vs0.20±0.02)差异具有统计学意义(P<0.05);海马钩回间距、皮质脑萎缩、混合型脑萎缩与认知功能障碍呈负相关(分别为r=-0.094,P=0.034,r=-0.156,P≈0.000,r=-0.147,P≈0.000),以海马钩回间距20mm提示老年认知功能障碍的敏感度最高(98.14%),混合型脑萎缩的特异度(84.86%)、准确度最高(72.80%)。结论CT测量相关脑结构,判断脑萎缩类型可以为老年认知功能障碍的诊断提供有价值的信息。     

A Bayesian iterative transmission gradient reconstruction algorithm for cardiac SPECT attenuation correction

Background  High-quality attenuation maps are critical for attenuation correction of myocardial perfusion single photon emission computed tomography studies. The filtered backprojection (FBP) approach can introduce errors, especially with low-count transmission data. We present a new method for attenuation map reconstruction and examine its performance in phantom and patient data. Methods and Results  The Bayesian iterative transmission gradient algorithm incorporates a spatially varying gamma prior function that preferentially weights estimated attenuation coefficients toward the soft-tissue value while allowing data-driven solutions for lung and bone regions. The performance with attenuation-corrected technetium 99m sestamibi clinical images was evaluated in phantom studies and in 50 low-likelihood patients grouped by body mass index (BMI). The algorithm converged in 15 iterations in the phantom studies. For the clinical studies, soft-tissue estimates had significantly greater uniformity of mediastinal coefficients (mean SD, 0.005 cm⁻¹ vs 0.011 cm⁻¹; P<.0001). The accuracy and uniformity of the Bayesian iterative transmission gradient algorithm were independent of BMI, whereas both declined at higher BMI values with FBP. Attenuation-corrected perfusion images showed improvement in myocardial wall variability (4.8% to 4.1%, P=.02) for all BMI groups with the new method compared with FBP. Conclusion  This new method for attenuation map reconstruction provides rapidly converging and accurate attenuation maps over a wide spectrum of patient BMI values and significantly improves attenuation-corrected perfusion images.     

Digital computer analysis of dermatoscopical images of 260 melanocytic skin lesions; perimeter/area ratio for the differentiation between malignant melanomas and melanocytic nevi

BACKGROUND: Digital computer analysis of dermatoscopical images has been reported to facilitate the differential diagnosis of pigmented skin lesions in recent years. OBJECTIVE: The aim of our study was to perform digital computer analysis of a set of different melanocytic lesions and compare the objective results. METHODS: The set of 260 melanocytic lesions (150 excised difficult cases (46 melanomas, 47 atypical nevi, 57 common nevi and 110 unexcised common nevi) was automatically analysed by the digital dermatoscopical system microDERM. We searched for differences in asymmetry, size, compactness and colour distribution. Perimeter/area ratio was calculated. RESULTS: The perimeter/area ratio was detected as the most important criterion for differentiation between malignant and benign melanocytic lesions (sensitivity 91.3% and specificity 90.7% for malignant melanomas vs. all benign nevi; sensitivity 91.3% and specificity 80.8% for melanomas vs. clinically atypical nevi). Differences in size of the lesion, shape and asymmetry of colour were found and statistically verified. Using step-wise logistic regression the formula for calculation of probability of malignant nature of every analysed lesion was constructed. CONCLUSION: The perimeter/area ratio is a simple parameter for the differential diagnosis of melanocytic skin lesions.     

AN-132 block of cardiac sodium channels: A gate-related receptor analysis

Summary Based on the gate-related receptor hypothesis, an analysis of kinetics of AN-132, a new antiarrhythmic agent, blockade of cardiac sodium channels and the gate-related receptor which is bound by the drug was performed by computer simulation. Model-predicted apparent rates of onset of AN-132 (30 μmol/L) blocking were 0.051, 0.038, and 0.034 AF⁻¹ at stimulation frequencies of 1.0, 2.0 and 3.0 Hz, respectively. The time constant of recovery from block by AN-132 at resting potential -90 mV was 39.5 s. These findings are in agreement with those experimental data documented. The analysis of gate-related receptor shows that AN-132 binds the inactivation gate-related receptor, and the binding and unbinding are modulated by the inactivation process.     

Clinical characteristics of rapidly progressive leuko-araiosis

Introduction – 38 patients found to have either pure leuko-araiosis (LA) or LA combined with infarction(s) on computer tomography (CT) in 1989 were re-examined in 1992 in order to evaluate the progression of LA. The follow-up period averaged 3.2 years. Material and methods - The clinical and radiological data on patients in 1989 were collected from hospital records and re-evaluated. The patients were re-examined clinically (including 24 hour ambulatory blood pressure measurement), and neuroradiologically (CT) in 1992 for this study. Results – 11 (29%) patients were found to have significant (rapid) progression of the extent of LA on CT during the follow-up. At baseline, there was no significant difference in the mean number of brain infarctions between the groups with progressing (prLA) and non-progressing LA (nprLA) or between the number of cortical and central infarctions within these groups. At follow-up, the total number of infarctions had increased significantly in both groups, but it was mostly because of the increase in cortical infarctions in the prLA group (p = 0.043) and, conversely, the central ones in the nprLA group (p = 0.011). prLA was found to be related to heart failure (82% vs 37%, p = 0.029) and atrial fibrillation (55% vs 19%, p = 0.047), whereas nprLA was strongly associated with a sudden onset of symptoms (78% vs prLA 18%, p = 0.001) like a-true brain infarction. Other clinical factors, including mean blood pressure and heart rate, did not clearly differentiate between the groups. Conclusion - The results suggest that there are different subgroups of patients with LA associated with various vascular factors. The occurrence of LA is not related to the distribution of infarctions. The progression of LA is not related to the number of brain infarctions or to the simultaneous increase of infarctions on CT.     

COMPUTER-BASED SURGICAL AUDIT PROGRAMS: A REVIEW OF THREE CURRENT OPTIONS

Background : In order to find the most useful computerized auditing system for the needs of the QE II Hospital surgical department three surgical auditing software programs were assessed. Methods : The Otago University Surgical Auditing Program, the Australian Surgical Auditing Program, and RACS-Audit were trialled for a period of 1 month each. The software programs were evaluated to find the time requirements for data entry, the level of surgical knowledge needed for effective audit information entry, and the perceived usefulness of the generated reports. Results : It was found that the Otago University program best suited the needs of the department. This system was designed for use in a hospital environment with multiple users. The method of data collection was simple and rapid. Entry of data into the program was logical, well structured and able to be performed by both junior medical staff and clerical staff. Reports generated by this system included information in an appropriate format for the departments' morbidity and mortality meetings. Conclusion : Personal computers are an ideal tool for the undertaking of surgical audit. Software programs are designed for different uses and should be critically assessed to ensure that the method of data entry, the time involved, and the reports generated enable an efficient and effective audit to be carried out.