Common injuries in horseback riding. A review

The most common location of horse-related injuries is the upper extremity (24% to 61%) with injuries to the lower extremity second in frequency (36% to 40%). The head and face sustain 20% of horse-related injuries. The most common type of injury is a soft tissue injury (92% to 1%), followed by a fracture (57% to 3%). Concussion is the third most common type of injury (63% to 2%). The most frequent cause of hospitalisation is concussion (38% to 4%) with fracture second. The most common injury which leaves residual impairment is injury to the central nervous system. The age at which most injury occurred is less than 21 years. In the latest NEISS report (1987-1988), injuries have decreased in the younger riders, but have increased in the older riders (above 24 years). More women are injured than men, but over the age of 44 years more men are injured than women, with the difference more marked in the 1987-1988 NEISS report. Previous horse-related injuries are reported frequently (37% to 25%). In mortality studies from Australia and the United States, head injuries caused the majority of deaths (78% and 60%), followed by chest injuries (9%). In the Australian study each sex had 50% of the deaths. In the United States, 60% were male, 40% female. Above the age of 24 years male deaths increasingly predominate, being 15 male deaths to 1 female above the age of 64. Concussion is divided into 3 divisions of severity which require different medical evaluation and treatment: mild in which rider is stunned or disoriented for a brief period; moderate in which there is loss of consciousness for less than 5 minutes; and severe in which there is a loss of consciousness for more than 5 minutes. Investigative need is cited in the areas of previous horse-related injury, lessons, experience vs knowledge, epilepsy, drowning, gender, deaths, safety helmets, stirrups, and body protectors. No horse is a safe horse; some are safer than others but the horse is a potentially lethal animal. Prevention of accidents and injuries is dependent upon using knowledge previously obtained from studying horse activities. Much more information is available than in the past through the medical studies that have been done and the recommendations made by these investigators. The medical community has a responsibility to educate the horse riding public and to participate in investigations requested by the horse organizations.(ABSTRACT TRUNCATED AT 400 WORDS)     

Benign osteochondromas and exostotic chondrosarcomas: evaluation of cartilage cap thickness by ultrasound

Ultrasonography (US) enables accurate assessment of the cartilage cap of exostoses. The cartilage cap appears as a hypoechoic layer covering the hyperechoic surface of the calcified part. Measurements of cap thickness with US were compared with measurements performed on pathological specimens in 22 resected exostoses and 2 exostotic chondrosarcomas. The US measurements proved to be very accurate, with a mean measurement error of less than 2 mm for cartilage caps less than 2 cm thick. The detection rate and measurement accuracy of US were higher than with computed tomography (CT) and comparable to magnetic resonance imaging (MRI), which were available in 14 and 10 cases, respectively. US appears to be a good procedure for evaluating the cartilage cap, which is usually thin for a benign exostosis and thick for a malignancy. In addition, other complications — such as bursa formation — are easily recognizable. The sole limitation is that US cannot visualize the cartilage cap when it is inwardly orientated or deeply located in soft tissues, which are both, however, relatively uncommon situations.     

The selenium-75-homocholic acid taurine test reevaluated: combined measurement of fecal selenium-75 activity and 3 alpha-hydroxy bile acids in 211 patients

The recommended reference values for the selenium-75-homocholic acid taurine (75SeHCAT) test, used in the analysis of chronic diarrhea, were evaluated in 211 patients by comparing simultaneous measurements of 3 alpha-hydroxy bile acids and 75Se activity in daily collected stools. An initial evaluation in 11 patients showed that the fecal collection method, which allows inspection and additional analysis of stools, was equivalent to the abdominal retention method. Selenium-75-HCAT whole-body retention half-life (WBR50) was greater than 2.8 days in less than 10% of the patients with bile acid malabsorption and less than 1.7 days in less than 10% of the normals. We recommend that a 75SeHCAT WBR50 less than 1.7 days is abnormal, a WBR50 greater than 2.8 days is normal, and a WBR50 in the range 1.7-2.8 days is equivocal, which was the case in 48% (94/195) of the patients in this study.     

Sysmex XT-1800I血液分析仪临床应用评价

目的　探讨SysmexXT 180 0I实验室体外诊断血液分析仪的临床应用价值。方法　采用随机和不随机选择标本方法 ,计算精密度、携带污染率、总重复性、白细胞分类的鉴定、可比性等对SysmexXT 180 0I全自动五分类血液分析仪进行评价。结果　精密度CV值均在设计规定范围内 ,总重复性CV <5 %符合标准 ;携带污染率 <2 %符合标准要求 ;仪器白细胞分类与显微镜目测白细胞分类相关性相关系数为 :r =0 .5 61～ 0 .987,仪器与KX 2 1CBC参数测定的相关系数为 0 .999～ 0 .93 2之间 ;可比性P >0 .4～ 0 .5。结论　对XT 180 0I几项主要指标鉴定结果符合设计要求 ,是较好的全自动五分类仪器 ,能满足临床血液常规分析     

凝血3项测定在妊高征中的意义

目的　探讨妊高征患者血浆凝血因子的变化及临床意义。方法　用全自动凝血仪检测 5 2例妊高征患者血浆凝血酶原时间 (PT)、部分活化凝血活酶时间 (APTT)和纤维蛋白原 (Fg)的变化 ,与 48例育龄非孕妇女及 5 0例正常妊娠妇女作比较分析。结果　PT ,APTT重度妊高征组 <中度妊高征组 <正常妊娠组 <正常对照组 ,妊高征组与正常妊娠组比较差异有显著意义 (P <0 .0 5 ) ;Fg含量重度妊高征组 >中度妊高征组 >正常妊娠组 >正常对照组 ,妊高征组与正常妊娠组比较差异有非常显著意义 (P <0 .0 0 1)。结论　妊高征患者存在明显的高凝状态 ,定期检查PT ,APTT ,Fg的变化 ,对指导临床使用适当的抗凝剂治疗 ,有一定的意义。     

Use of (99m)Tc from a commercial (99)Mo/(99m)Tc generator as yield tracer for the determination of (99)Tc at low levels.

The concentrations of (99)Tc and impurity radionuclides in the (99m)Tc tracer solution obtained from a commercial (99)Mo/(99m)Tc generator were measured by gamma spectrometry and liquid scintillation counting. (99)Mo and (103)Ru were found in the (99m)Tc eluate. A simple separation using two extra alumina cartridges was investigated to purify the eluate to obtain a suitable (99m)Tc tracer with low (99)Tc concentration. The activity ratio of (99)Tc/(99m)Tc in the prepared (99m)Tc solution is lower than 15 x 10(-9), which is higher than the theoretical ratio of less than 10 x 10(-9). The possible reason is discussed. The (99)Tc in the 20 kBq spiked (99m)Tc tracer was found to be less than 0.3 mBq, which is lower than the detection limit of the radiometric method used for environmental samples. The purified (99m)Tc eluate is used as yield tracer for the determination of low levels of (99)Tc in environmental samples.     

孤立肺结节的增强CT诊断新进展

孤立肺结节(SPN)的增强CT诊断是近年来研究热点之一,检查方法分为动态和多期增强扫描两类,以SPN的强化程度、结节-主动脉强化值比(S/A)、时间-密度曲线类型、灌注值、强化模式、肿瘤血管征等作为诊断依据。以强化值<15HU、S/A<6%为界值,可区分出良性结节;时间-密度曲线类型有助于恶性与炎性结节的鉴别;肿瘤血管征可作为特异性诊断指征;包膜样强化或内壁规则的周围强化高度提示结核的诊断。     

Bochdalek hernia: prevalence and CT characteristics

The chest and abdominal computed tomography (CT) scans of 940 patients were reviewed to determine the prevalence of Bochdalek hernias and to evaluate the widely held concept that left-sided hernias occur more than nine times as often as right-sided hernias. Sixty Bochdalek hernias were identified in 52 patients, a prevalence of 6%, which is more than 100 times more frequent than previously reported. Left-sided hernias were found approximately twice as often as right-sided hernias. The Bochdalek hernia is a much more common congenital anomaly in the asymptomatic adult than previously thought and frequently can be identified on routine chest and abdominal CT images.     

3D MRA coronary axis determination using a minimum cost path approach.

A method is introduced to automatically find the coronary axis based on two or more user-defined points, even in the presence of a severe stenosis. The coronary axis is determined by finding a minimum cost path (MCP) in a feature image in which the tubular-like structures are enhanced. The results of the proposed method were compared with manually drawn central axes to estimate the accuracy. In 32 3D TFE-EPI acquisitions of patients and volunteers, 14 right coronary arteries (RCAs), 15 left anterior descending arteries (LADs), and eight left circumflex arteries (LCXs) were manually tracked twice by two operators to determine a reference axis and to assess the inter- and intra-user variability. On average, the maximum distance to the reference axis, based on only two user-defined points, is less than 1.5 mm; the average distance is around 0.65 mm, which is less than the average in-plane resolution. The results of the method are comparable to those of the manual operators.     

Economists and the next 150 years

This article is concerned with the role of economics in society, and concludes that the dominant system resembles a political, science more closely than a social science, justifying a political system rather than addressing current problems in the analytical manner which might be expected of a science. The importance of economics in advising on modern problems, and the idea that the discipline ought to be related to and based upon human rights, is discussed.     

Caffeine ingestion during exercise to exhaustion in elite distance runners. Revision.

Caffeine is currently being used as an ergogenic aid by many athletes. The aim of this research was to determine whether a large dose of caffeine (10 mg.kg-1) taken immediately prior to the start of endurance exercise would have the desired effect of increasing endurance performance. Six males, who were not habitual caffeine users and who had performed at least two marathons, served as subjects in this experiment. They ran on a treadmill at a speed which had been calculated would elicit 75% of their VO2max for 45 minutes, after which time the speed was increased by two miles per hour till exhaustion. During the caffeine trial the athletes ran further than either the control or placebo conditions (p less than 0.05). Blood lactate values did not change across condition except for the final collection period which was significantly higher in the caffeine trial (p less than 0.05). As expected there was a significant time effect in all conditions (p less than 0.0001). Blood triglycerides after the start of the test were always higher in the caffeine condition but this was only significant at the 45 minute and end of exercise collection periods (p less than 0.05). The results suggest that endurance athletes can use caffeine just prior to exercise rather than one to three hours prior to exercise.     

A technique for computer-guided stereotaxis without preoperative head fixation

A CT-guided stereotactic method is described which uses a standard BRW frame for probe insertion but which does not require frame fixation to the skull during the localizing scan. The patient is instead scanned wearing three radiopaque scalp markers, and new software utilized to obtain BRW coordinates. Acceptable accuracy for targets greater than one centimeter in diameter was obtained in phantom trials and in three case reports. This technique may be helpful for stereotactic targets greater than one centimeter in diameter and when preoperative head fixation is not desirable or possible.     

关于正常青年人步态竖直方向力的检测与统计分析

目的对步态研究中力学参数与姿态控制之间的关系进行合理有效的评价。方法运用自行研制的测力系统 ,对 2 7个无运动系统病史的青年人进行了步态力学数据采样 ,并做出特征双峰曲线。从曲线上提取 7个特征量 ,运用统计学方法分析特征量变异系数CV ,左右脚的绝对对称指标ASI,并用t 检验法分析特征量在左右脚和性别上的差异性。结果步态第一特征时间 (TZ1 )CV值为 1 4.49% ,离散度较大 ;在ASI满足一般要求基础上 ,用t 检验法分析左右脚差异性 ,得到FZ2 的P值为 0 .0 368( <0 .0 5 ) ,存在明显的左右脚差异性 ;同样方法分析男女步态差异性 ,FZ2 的P值小于 0 .0 1 ,表明有显著差异性。结论在特征量的重复性、离散度、对称性、差异性等方面得到了一些有意义的结论     

Comparison of dual-energy and conventional chest radiography for nodule detection

This paper presents the results of a nodule detection study, using a Humanoid chest phantom, which was designed to evaluate the performance of two types of dual-energy and conventional (single-energy) chest radiography. The film-screen apparatis were used as image detectors for all imaging modalities. The area under the ROC curve and the cumulative true-positive fraction both were used as performance indexes in the evaluation. Because of the small number of false-positive responses in the observer studies, the cumulative true-positive fraction was eventually regarded as a more conclusive index of accuracy than the area under the ROC curve to make a reasonable conclusion. Both dual-energy techniques, dual- and single-exposure, were found to be superior to conventional chest radiography, P less than 0.0005 and P less than 0.006 for dual- and single-exposure techniques, respectively. The difference between the two dual-energy techniques was statistically insignificant, P less than 0.47. We concluded that the dual-energy, single-exposure technique is worthy of further clinical study based on these encouraging results and because of the ease with which the technique can be implemented.     

Ultrasonic examination of the pancreas.

Gray scale scanners allow the demonstration of much more anatomical detail than was possible with the older type scanners. The initial step in the ultrasonic examination of the pancreas is display of the anatomical detail of the portal vasculature which provides a guidepost to the pancreas. Pancreatitis is characterized by a diffusely enlarged echo-free pancreas. Pancreatic pseudocyst is almost always an echo-free unilocular fluid collection. The size of a pancreatic pseudocyst can be measured so that progress can be assessed. Pseudocysts located in the region of the tail of the pancreas may be best demonstrated by scanning from the back over the left kidney. Pancreatic pseudocysts may be partly solid. Pancreatic carcinoma appears as a localized relatively echo-free, poorly defined solid mass which attenuates the ultrasound beam. Pancreatic carcinoma smaller than 2 cm in diameter are particularly difficult to diagnose by ultrasonic examination. Pancreatic carcinoma may be difficult to distinguish from chronic pancreatitis. Dilated bile ducts can be demonstrated and point to extrahepatic biliary obstruction. Serial ultrasonic scans have been suggested as a means of monitoring the response of pancreatic tumors to therapy. The relative diagnostic value of endoscopic retrograde cannulation of the pancreatic ducts and ultrasound has not as yet been established. Ultrasonic examination is easier to perform and less expensive than any other pancreatic imaging procedure other than the upper gastrointestinal barium examination.     

The application of the linear-quadratic dose-effect equation to fractionated and protracted radiotherapy

The linear-quadratic (LQ) dose-effect formalism is currently providing new perspectives into the ways in which alterations in the dose per fraction in conventional radiotherapy may be used to bring about improved results with respect to early or late normal tissue reactions. In this paper, using a model initially developed by Roesch, the LQ equations are explored further in terms of dose-rate rather than dose. By the incorporation of one other parameter, mu, which relates to the rate of repair of sub-lethal radiation damage, a more general formalism is obtained. In particular, equations are derived which can be used to examine the relative effectiveness of different treatment regimes, including those involving decaying sources. Such equations are of wider applicability than other LQ derivations which relate only to dose-response relationships. The extended equations, which are fully consistent with the existing LQ method, are also shown to lead directly to other independently established, relationships for protracted irradiation. The nature of the link between high and low dose-rate treatments is discussed, and some worked examples provide indications of how the new equations may be used to assess further the potential clinical benefits of low dose-rate treatments and permanent implants.     

CNR enhancement in the presence of multiple interfering processes using linear filters

Given several images of the same slice, a linear filter can produce an image in which the contrast-to-noise ratio (CNR) between pathological and normal tissues is greater than in any of the initial images. To distinguish the pathology from more than one tissue, the filter should optimize the set of CNRs between the pathology and each of the interfering tissues. We define the optimal filter as the one which provides the largest value for the minimum CNR in the set and show how it is selected from a field of only four possibilities. The filter is demonstrated with both experimental phantom studies and clinical cases. Filter performance is compared with that of other techniques for distinguishing a desired feature from more than one interfering process.     

On X-ray back-scattering to detect hidden cracks in multi-layer structures.

A method that uses X-ray scanning to detect subsurface cracks is described. The method deals with samples typical of aircraft structures for which access is limited to one surface and a crack is hidden within the first substrate layer beneath the surface layer. A single-scatter model for the total response due to all X-rays that scatter once in one of the substrate layers and then pass through the top surface of the crack region and escape the target is developed. In this model, the crack is treated as a region of lower average density, and hence interaction coefficient, than the unaffected bulk material. The EGS4 Monte Carlo code also is used to estimate multiple-scattering response assuming the crack region is a thin void. These two models provide consistent results which indicate that properly designed X-ray back-scatter scanners can identify the presence of hidden cracks that extend through the substrate layer and are greater than about 1 cm in length.     

'Inflammatory' abdominal aortic aneurysms

The term 'inflammatory aneurysm' is used to describe a variant of atherosclerotic abdominal aortic aneurysms in which the wall of the aneurysm is unusually thick and surrounded by extensive fibrosis and adhesions. Repair of these aneurysms is associated with a higher mortality and morbidity than repair of those which are non-inflammatory, so that diagnosis prior to surgery is desirable. The use of computed tomography (CT) and ultrasound in this differentiation is discussed. The correct diagnosis was made in 16 out of 17 by CT, but in only three of nine cases who had ultrasound scans.