Historical Evolution of Imaging Techniques for the Evaluation of Pulmonary Embolism.

As we celebrate the 100th anniversary of the founding of the Radiological Society of North America (RSNA), it seems fitting to look back at the major accomplishments of the radiology community in the diagnosis of pulmonary embolism. Few diseases have so consistently captured the attention of the medical community. Since the first description of pulmonary embolism by Virchow in the 1850s, clinicians have struggled to reach a timely diagnosis of this common condition because of its nonspecific and often confusing clinical picture. As imaging tests started to gain importance in the 1900s, the approach to diagnosing pulmonary embolism also began to change. Rapid improvements in angiography, ventilation-perfusion imaging, and cross-sectional imaging modalities such as computed tomography (CT) and magnetic resonance imaging have constantly forced health care professionals to rethink how they diagnose pulmonary embolism. Needless to say, the way pulmonary embolism is diagnosed today is distinctly different from how it was diagnosed in Virchow's era; and imaging, particularly CT, now forms the cornerstone of diagnostic evaluation. Currently, radiology offers a variety of tests that are fast and accurate and can provide anatomic and functional information, thus allowing early diagnosis and triage of cases. This review provides a historical journey into the evolution of these imaging tests and highlights some of the major breakthroughs achieved by the radiology community and RSNA in this process. Also highlighted are areas of ongoing research and development in this field of imaging as radiologists seek to combat some of the newer challenges faced by modern medicine, such as rising health care costs and radiation dose hazards.

Staging of idiopathic pulmonary fibrosis: past, present and future.

Idiopathic pulmonary fibrosis (IPF) is traditionally staged with terms such as "mild", "severe", "early" and "advanced" based on pulmonary function tests. This approach allows physicians to monitor disease progression and advise patients and their families. However, it is not known if the stages of this model reflect distinct biological or clinical phenotypes and the therapeutic and prognostic value of this system is limited. Novel methods of IPF staging have recently been developed. The GAP model includes four baseline variables that were found to be predictive of outcome, as identified by logistic regression. These factors are: gender (G), age (A) and two lung physiology variables (P) (forced vital capacity and diffusing capacity of the lung for carbon monoxide). The clinical utility and accuracy of staging models may be further improved in the future by the integration of dynamic parameters that can be measured over time, as well as biological data from biomarkers which may be able to directly measure disease activity. The development of an evidence-based, multidimensional IPF staging model that builds on the current staging approaches to IPF is an important objective for improving the management of IPF.

An assessment of pulmonary function testing and ventilatory kinematics by optoelectronic plethysmography.

New advances in computer processing and imaging have allowed the development of innovative techniques to assess lung function. A promising methodology is optoelectronic plethysmography (OEP). OEP evaluates ventilatory kinematics through the use of infrared imaging. Markers are placed, and images read on the chest, back and abdomen of subjects. Currently, this system is used mainly in research settings, but in the future may have broad applicability to patient populations such as very young children, patients with neuromuscular disease and patients who cannot be tested with classical spirometry testing. This paper presents the history and development of OEP, along with a summary of the OEP methodology, a discussion of research findings and results to date, as well as application and limitations.

Mechanics of the lung in the 20th century.

Major advances in respiratory mechanics occurred primarily in the latter half of the 20th century, and this is when much of our current understanding was secured. The earliest and ancient investigations involving respiratory physiology and mechanics were frequently done in conjunction with other scientific activities and often lacked the ability to make quantitative measurements. This situation changed rapidly in the 20th century, and this relatively recent history of lung mechanics has been greatly influenced by critical technological advances and applications, which have made quantitative experimental testing of ideas possible. From the spirometer of Hutchinson, to the pneumotachograph of Fleisch, to the measurement of esophageal pressure, to the use of the Wilhelmy balance by Clements, and to the unassuming strain gauges for measuring pressure and rapid paper and electronic chart recorders, these enabling devices have generated numerous quantitative experimental studies with greatly increased physiologic understanding and validation of mechanistic theories of lung function in health and disease.

Respiratory impedance measurements for assessment of lung mechanics: focus on asthma.

This review discusses the history and current state of the art of the forced oscillation technique (FOT) to measure respiratory impedance. We focus on how the FOT and its interaction with models have emerged as a powerful method to extract out not only clinically relevant information, but also to advance insight on the mechanisms and structures responsible for human lung diseases, especially asthma. We will first provide a short history of FOT for basic clinical assessment either directly from the data or in concert with lumped element models to extract out specific effective properties. We then spend several sections on the more exciting recent advances of FOT to probe the relative importance of tissue versus airway changes in disease, the impact of the disease on heterogeneous lung function, and the relative importance of small airways via synthesis of FOT with imaging. Most recently, the FOT approach has been able to directly probe airway caliber in humans and the distinct airway properties of asthmatics that seem to be required for airway hyperresponsiveness. We introduce and discuss the mechanism and clinical implications of this approach, which may be substantial for treatment assessment. Finally, we highlight important future directions for the FOT, particularly its use to probe specific lung components (e.g., isolated airways, isolated airway smooth muscle, etc.) and relate such data to the whole lung. The intent is to substantially advance an integrated understanding of structure-function relationships in the lung.

[Fascinated by pulmonary function].

I would like to tell you about my 35 years of research, starting when I became a medical doctor, titled "Fascinated by Pulmonary Function". For the first 10 years, I studied the automation of pulmonary function tests and developed some automatic pulmonary function test apparatuses such as the spiro-computer, panspiro-computer, automatic respiratory resistant test apparatus and automatic respiratory central function test apparatus. For the next 15 years, I studied the relationships between some important pulmonary diseases and respiratory pulmonary functions. In particular, I studied respiratory efficiency and respiratory center functions. For the most recent 10 years, I have been studying the relationships between non-respiratory pulmonary functions and chronic respiratory diseases. I am studying the relationships between ATP(Adenosine Tri Phosphate) in the blood for the parameters of mitochondria function and pneumoconiosis and other chronic pulmonary diseases. I had very interesting results regarding DNA types of arteriosclerosis in chronic pulmonary emphysema. I thank all my research fellows during these 35 years from the bottom of my heart.