Prediction of suicide in military medical facilities.

The scope of the suicide problem is briefly reviewed and the distinction between actuarial and clinical prediction is discussed. Three approaches to the process of clinical prediction are (1) use of multiple predictors; (2) use of objective rating scales, and (3) psychodynamic formulation of risk. These are discussed and specific suggestions are offered for incremental implementation in military medical facilities depending on availability of psychiatric resources. The major warning signs of suicidal behavior are outlined and recommendations offered for training of ward personnel.     

Recent advances in medical physics

Some of the major interests in medical physics over the last few years have concerned the technical advances in Computed Tomography and high field Magnetic Resonance Imaging. This review discusses the introduction of Dual Source CT and explains how it can not only offer faster data acquisition but also operate with lower radiation doses. This provides enormous benefits for all patients, but for cardiac and pediatric examinations in particular. The advances in MRI at 7?T esla are also impressive, with better signal to noise; cardiac and musculoskeletal applications are discussed; technical improvements are work-in-progress for other applications.     

Solid waste management practices in U.S. Army medical treatment facilities

U.S. Army medical treatment facilities (MTFs) will be challenged to reduce waste as the Army internalizes as environmental ethic and privatizes solid waste management. A questionnaire was modified to survey solid waste management practices, participation in waste reduction and recycling programs, and solid waste management problems in 25 MTFs. Questionnaires were returned by 19 (76%) of the sites. Eighteen sites participated in waste reduction and recycling programs. Twelve sites used contractors to disinfect potentially infectious solid waste off site. Mean importance ratings of waste reduction and recycling were 2.00 and 1.83 (1 = very important; 5 = very unimportant), respectively. Limited staffing was ranked as the most significant waste management problem, followed by cost and regulatory compliance. More information on waste generation in MTFs is needed. The Army Medical Department should be presented as a model of environmental and natural resource stewardship for the health care industry.     

The role of medical imaging in paleoanthropology

Study of the health status of ancient populations relies on the detection and analysis of bone or dental lesions from skeletons. In the absence of clinical or biological data, the identification of a pathology relies on anatomic and radiographic findings. Three paleopathological cases are presented and macroscopic and imaging findings are discussed. These include one case of eosinophilic granuloma, one case of Ewing sarcoma, and one case of secondary hypertrophic osteoarthropathy. Each case illustrates the value and limitations of retrospective diagnosis; an etiologic diagnosis can either be possible, suggested or unknown. Multiple biases, related to specimen preservation and the frequent non-specific nature of bony changes, make paleopathological diagnosis challenging. As such, the use of medical imaging seems valuable in the evaluation of such lesions. It allows non-invasive evaluation of the bone, underlying pathology, and lesion comparison to finally narrow the differential diagnosis.     

浅谈用接口转换维修医疗设备

在维修医疗设备时很多用户工程师都遇到过这样的情况:已查明机器故障苦于没有现成备件可替换,需要向设备厂家购买,但价格昂贵,特别是早期的大型医疗设备.这时除了向厂家购买备件外,某些故障其实还可以用转换方式来实现,不但可以缩短停机时间,还能给医院节省一大笔费用.现将我院出现的几例设备故障及转换方法介绍如下.     

Application of the "rule of 72" in medical physics and dosimetry.

The "rule of 72," commonly applied to financial questions, is discussed as to its applicability in medical physics and dosimetry.     

The physics of diagnostic ultrasound.

Sound waves progress through a medium at a velocity that is characteristic of that medium. In a particular medium, wavelength and frequency are inversely related, so that short wavelengths can only be obtained at higher frequencies. A beam of sound will not be directional unless the object that is sending (or reflecting) it is at least several times longer than the wavelength. In tissue directional beams of 1 cm or less in width can be produced at frequencies of 1 MHz or more. Other things being equal, the higher the frequency, the narrower the beam. The attenuation of beams of sound in tissue at ultrasonic frequencies is directly and almost linearly related to frequency in that the higher the frequency, the greater the attenuation and the weaker the return signals. In choosing an operating frequency for a particular purpose, one must therefore bear in mind that the advantages of the higher frequencies (i.e., better resolution, both in range and azimuth) are obtained at the bost of a shorter effective range. Accordingly, one makes the best compromise by selecting the highest frequency that permits a range adequate for the purpose. In scanning the abdomens of adults where the range may be fairly long, a 2 MHz transducer is used. For cardiac studies in pediatric patients where the range is shorter and the structures smaller, a 5 MHz probe can be used. In the globe of the eye the structures are minute, the medium one in which losses are quite low and the range is very short, permitting the use of frequencies in the 10 to 20 MHz range.