放射線画像の物理的画質―基礎的概念と理論―

放射線画像診断において，X 線画像の物理的画質は正確な確定診断に影響を与える。高画質になるほど，診断の精度は上がる。X 線画像の画質は，三つの画質因子，すなわち，コントラスト，解像度（鮮鋭度），ノイズ（X線画像モトル）に影響されることはよく知られている。これら三つの因子は，物理的画質の基本的要素を構成する。撮像システムのコントラストは，通常X 線画像コントラストといわれるが，被写体（放射線）コントラスト，フィルムコントラスト（グラディエント）と一次線（散乱線）含有率に関係している。解像特性は，modulation transfer function (MTF)，またはline spread function (LSF) あるいは point spread function (PSF) で，また，画像ノイズ特性は，Wiener spectrum あるいは自己相関関数によって定量的に評価されている。本稿では，X 線撮像システムの画像コントラスト，MTF およびウィナースペクトルの基礎的概念と理論を解説した。In diagnostic radiologic examinations, diagnostic accuracy or correct diagnosis is influenced by the physical imagequality of radiographic images. As the physical image quality improves, the diagnostic accuracy is increased. It is known that the physical image quality is affected by three fundamental factors, namely, contrast, resolution (or sharpness), and noise (or radiographic mottle) of imaging systems. These three parameters constitute the fundamental components of physical imagequality. The contrast of an imaging system, commonly referred to as radiographic contrast (or image contrast), is related to the subject contrast (or radiation contrast), film contrast (or gradient), and primary (or scatter) fraction. The resolution of imaging systems has been determined by means of the modulation transfer function (MTF), line spread function (LSF),or point spread function (PSF). The image noise has been quantifi ed in terms of the Wiener spectrum or autocorrelation function. This article describes basic concept and theory for the radiographic contrast, MTF, and Wiener spectrum of radiographic systems.総

Heterogeneous dermatitis complaints after change in drinking water treatment: a case report

BACKGROUND: The disinfectant monochloramine minimizes the formation of potentially hazardous and regulated byproducts, and many drinking water utilities are shifting to its use. CASE PRESENTATION: After a drinking water utility serving 2.4 million people switched to monochloramine for residual disinfection, a small number of residents complained of dermatitis reactions. We interviewed 17 people about their symptoms. Skin appearance, symptoms, and exposures were heterogeneous. Five respondents had history of hives or rash that preceded the switch to monochloramine. CONCLUSION: The complaints described were heterogeneous, and many of the respondents had underlying or preexisting conditions that would offer plausible alternative explanations for their symptoms. We did not recommend further study of these complaints

Validation of the treatment identification strategy of the HEDIS addiction quality measures: concordance with medical record review

<p>Abstract</p> <p>Background</p> <p>Strategies to accurately identify the occurrence of specific health care events in administrative data is central to many quality improvement and research efforts. Many health care quality measures have treatment identification strategies based on diagnosis and procedure codes - an approach that is inexpensive and feasible but usually of unknown validity. In this study, we examined if the diagnosis/procedure code combinations used in the 2006 HEDIS Initiation and Engagement quality measures to identify instances of addiction treatment have high concordance with documentation of addiction treatment in clinical progress notes.</p> <p>Methods</p> <p>Four type of records were randomly sampled from VHA electronic medical data: (a) Outpatient records from a substance use disorder (SUD) specialty clinic with a HEDIS-qualified substance use disorder (SUD) diagnosis/CPT code combination (n = 700), (b) Outpatient records from a non-SUD setting with a HEDIS-qualified SUD diagnosis/CPT code combination (n = 592), (c) Specialty SUD Inpatient/residential records that included a SUD diagnosis (n = 700), and (d) Non-SUD specialty Inpatient/residential records that included a SUD diagnosis (n = 700). Clinical progress notes for the sampled records were extracted and two raters classified each as documenting or not documenting addiction treatment. Rates of concordance between the HEDIS addiction treatment identification strategy and the raters' judgments were calculated for each record type.</p> <p>Results</p> <p>Within SUD outpatient clinics and SUD inpatient specialty units, 92% and 98% of sampled records had chart evidence of addiction treatment. Of outpatient encounters with a qualifying diagnosis/procedure code combination outside of SUD clinics, 63% had chart evidence of addiction treatment. Within non-SUD specialty inpatient units, only 46% of sampled records had chart evidence of addiction treatment.</p> <p>Conclusions</p> <p>For records generated in SUD specialty settings, the HEDIS strategy of identifying SUD treatment with diagnosis and procedure codes has a high concordance with chart review. The concordance rate outside of SUD specialty settings is much lower and highly variable between facilities. Therefore, some patients may be counted as meeting the 2006 HEDIS Initiation and Engagement criteria without having received the specified amount (or any) addiction treatment.</p

Developing core elements and checklist items for global hospital antimicrobial stewardship programmes:a consensus approach

International audienc

Integrated Personal Health Records: Transformative Tools for Consumer-Centric Care

<p>Abstract</p> <p>Background</p> <p>Integrated personal health records (PHRs) offer significant potential to stimulate transformational changes in health care delivery and self-care by patients. In 2006, an invitational roundtable sponsored by Kaiser Permanente Institute, the American Medical Informatics Association, and the Agency for Healthcare Research and Quality was held to identify the transformative potential of PHRs, as well as barriers to realizing this potential and a framework for action to move them closer to the health care mainstream. This paper highlights and builds on the insights shared during the roundtable.</p> <p>Discussion</p> <p>While there is a spectrum of dominant PHR models, (standalone, tethered, integrated), the authors state that only the integrated model has true transformative potential to strengthen consumers' ability to manage their own health care. Integrated PHRs improve the quality, completeness, depth, and accessibility of health information provided by patients; enable facile communication between patients and providers; provide access to health knowledge for patients; ensure portability of medical records and other personal health information; and incorporate auto-population of content. Numerous factors impede widespread adoption of integrated PHRs: obstacles in the health care system/culture; issues of consumer confidence and trust; lack of technical standards for interoperability; lack of HIT infrastructure; the digital divide; uncertain value realization/ROI; and uncertain market demand. Recent efforts have led to progress on standards for integrated PHRs, and government agencies and private companies are offering different models to consumers, but substantial obstacles remain to be addressed. Immediate steps to advance integrated PHRs should include sharing existing knowledge and expanding knowledge about them, building on existing efforts, and continuing dialogue among public and private sector stakeholders.</p> <p>Summary</p> <p>Integrated PHRs promote active, ongoing patient collaboration in care delivery and decision making. With some exceptions, however, the integrated PHR model is still a theoretical framework for consumer-centric health care. The authors pose questions that need to be answered so that the field can move forward to realize the potential of integrated PHRs. How can integrated PHRs be moved from concept to practical application? Would a coordinating body expedite this progress? How can existing initiatives and policy levers serve as catalysts to advance integrated PHRs?</p

Alternative Transportation Energy

Transportation energy issues are moving to the forefront of the public consciousness in the U.S. and particularly California, and gaining increasing attention from legislators and regulators. The three principal concerns motivating interest in transportation energy are urban air quality, oil dependence, and the threat of global warming. Transportation fuels are a principal contributor to each of these. The transportation sector, mostly motor vehicles, contributes roughly half the urban air pollutants, almost one-third of the carbon dioxide, and consumes over 60% of all petroleum