Organ-specific dose coefficients derived from Monte Carlo simulations for historical (1930s to 1960s) fluoroscopic and radiographic examinations of tuberculosis patients.

This work provides dose coefficients necessary to reconstruct doses used in epidemiological studies of tuberculosis patients treated from the 1930s through the 1960s, who were exposed to diagnostic imaging while undergoing treatment. We made use of averaged imaging parameters from measurement data, physician interviews, and available literature of the Canadian Fluoroscopy Cohort Study and, on occasion, from a similar study of tuberculosis patients from Massachusetts, United States, treated between 1925 and 1954. We used computational phantoms of the human anatomy and Monte Carlo radiation transport methods to compute dose coefficients that relate dose in air, at a point 20 cm away from the source, to absorbed dose in 58 organs. We selected five male and five female phantoms, based on the mean height and weight of Canadian tuberculosis patients in that era, for the 1-, 5-, 10-, 15-year old and adult ages. Using high-performance computers at the National Institutes of Health, we simulated 2,400 unique fluoroscopic and radiographic exposures by varying x-ray beam quality, field size, field shuttering, imaged anatomy, phantom orientation, and computational phantom. Compared with previous dose coefficients reported for this population, our dosimetry system uses improved anatomical phantoms constructed from computed tomography imaging datasets. The new set of dose coefficients includes tissues that were not previously assessed, in particular, for tissues outside the x-ray field or for pediatric patients. In addition, we provide dose coefficients for radiography and for fluoroscopic procedures not previously assessed in the dosimetry of this cohort (i.e. pneumoperitoneum and chest aspirations). These new dose coefficients would allow a comprehensive assessment of exposures in the cohort. In addition to providing newly derived dose coefficients, we believe the automation and methods developed to complete these dosimetry calculations are generalizable and can be applied to other epidemiological studies interested in an exposure assessment from medical x-ray imaging. These epidemiological studies provide important data for assessing health risks of radiation exposure to help inform the current system of radiological protection and efforts to optimize the use of radiation in medical studies.

Dr. Hyacinthe Guilleminot and the first respiratory and cardiac synchronisation systems for obtaining radiological images. / El Dr. Hyacinthe Guilleminot y los primeros sistemas de sincronización respiratoria y cardíaca para obtención de imagen radiológica.

In an era when it was not possible to achieve quality x-rays with short exposure times, the need to obtain chest images without movement led the French doctor Emré Hyacinthe Guilleminot to construct a machine that repeatedly emitted x-rays only when desired during the respiratory cycle. His aim was to create a satisfactory radiograph from multiple short bursts performed at the moment of inhalation or exhalation, based on Charles Bouchard's research on heart disease. He extended his idea to radiography of the heart, creating a system that enabled images to be obtained disassociating the phases of heartbeat. This article seeks to explain the basic functioning of these mechanisms, and to recover previous research papers that led to their creation. We will also retrieve biographical and personal data of the two people involved - one directly, the other indirectly - in these novel inventions.

History and Evolution of the Barium Swallow for Evaluation of the Pharynx and Esophagus.

This article reviews the history of the barium swallow from its early role in radiology to its current status as an important diagnostic test in modern radiology practice. Though a variety of diagnostic procedures can be performed to evaluate patients with dysphagia or other pharyngeal or esophageal symptoms, the barium study has evolved into a readily available, non-invasive, and cost-effective technique that can facilitate the selection of additional diagnostic tests and guide decisions about medical, endoscopic, or surgical management. This article focuses on the evolution of fluoroscopic equipment, radiography, and contrast media for evaluating the pharynx and esophagus, the importance of understanding pharyngoesophageal relationships, and major advances that have occurred in the radiologic diagnosis of select esophageal diseases, including gastroesophageal reflux disease, infectious esophagitis, eosinophilic esophagitis, esophageal carcinoma, and esophageal motility disorders.

[Development of intraoperative C-arm imaging in trauma surgery]. / Entwicklung der intraoperativen C-Bogenanwendung in der Unfallchirurgie.

Since the earliest beginnings of using X-rays, two forms of examination techniques have been known: X-ray imaging and projection onto films. The new technology very rapidly became widespread. Just a few months after the discovery of the so-called X-rays, the first fluoroscopes (instruments for visualizing internal structures) were constructed and constantly improved upon. If the operation took place in bright light, a cryptoscope was needed for examination. Since 1984 fluoroscopic examinations or interventions performed under X-ray control are only permitted when systems are used that are equipped with an image intensifier video chain or a digital image receiver with TV monitor.At about the beginning of the new century the first digital imaging systems with solid-state detectors were put into service. Flat panel detectors offer high-quality imaging with good spatial resolution and contrast recognition. At the present time, storable intraoperative three-dimensional diagnostic imaging is available.

Beyond the radiograph: radiological advances in surgery.

Advancements in imaging techniques and the development of new radiological modalities have opened exciting venues for furthering surgical specialties. From the initial and innovative discovery of the radiograph by Röentgen, radiology has found an important and central role in the expansion of surgical possibilities. In this historical review, the innovation and discoveries behind the development of the radiograph, fluoroscopy, angiography and ultrasound are examined. Additionally, the use of these imaging modalities in surgery is discussed. Learning from the discoveries of history's giants, we hope to advance our own knowledge and create new possibilities, a future that will hold great promise for the radiologists and surgeons of tomorrow.

The evolution of the endonasal approach for craniopharyngiomas.

Craniopharyngiomas have always been an extremely challenging type of tumor to treat. The transsphenoidal route has been used for resection of these lesions since its introduction. The authors present a historical review of the literature from the introduction of the endonasal route for resection of craniopharyngiomas until the present. Abandoned early due to technological limitations, this approach has been expanded both in its application and in its anatomical boundaries with subsequent progressive improvements in outcomes. This expansion has coincided with advances in visualization devices, imaging guidance techniques, and anatomical understanding. The progression from the use of headlights, to microscopy, to endoscopy and fluoroscopy, and finally to modern intraoperative magnetic resonance-guided techniques, combined with collaboration between otolaryngologists and neurosurgeons, has provided the framework for the development of current techniques for the resection of sellar and suprasellar craniopharyngiomas.

Patient and staff radiation doses from early radiological examinations (1899-1902).

A source of data on radiographic and fluoroscopic examinations, including radiographic technique factors, was used in conjunction with information about cold-cathode X-ray apparatus to estimate patient and staff radiation doses for the years 1899 to 1902 at the Forth Banks Infirmary, Newcastle-upon-Tyne. Physical evidence from representative apparatus of the period was used with a beam spectral simulation program to characterize the X-ray beam, and information about the electrical supply waveform was produced by experimental operation of a contemporary induction coil. Results are given in terms of skin entrance dose, and these are compared with modern values. An estimate of the annual dose received by the radiographer known to have carried out all of the examinations within this period is also given.

Cardiac computed tomography imaging: a history and some future possibilities.

Cardiac computed tomography (CT) is a special subset of CT, a subject about which much has been written in terms of the underlying concepts and mathematics and the sociologic impact. Cardiac CT has passed through three, chronologically overlapping, developmental stages and is now in its fourth stage of development. The first stage was fluoroscopy-based CT (1972-1995) stimulated by physiologic research needs, and the next was clinical CT-based exploration (1975-1980) of the potential of clinical CT in cardiology. This was followed by the electron beam CT-based stage (1980-present), which was the first CT approach applicable to clinical cardiology. Finally, volume-scanning CT imaging methods achieved with multislice scanning approaches of helical CT and by flat panel-based CT (1990-present), show great promise for clinically applicable CT of the cardiovascular system.

Baring the sole. The rise and fall of the shoe-fitting fluoroscope.

One of the most conspicuous nonmedical uses of the x-ray was the shoe-fitting fluoroscope. It allowed visualization of the bones and soft tissues of the foot inside a shoe, purportedly increasing the accuracy of shoe fitting and thereby enhancing sales. From the mid 1920s to the 1950s, shoe-fitting fluoroscopes were a prominent feature of shoe stores in North America and Europe. Despite the widespread distribution and popularity of these machines, few have studied their history. In this essay we trace the origin, technology, applications, and significance of the shoe-fitting fluoroscope in Britain, Canada, and the United States. Our sources include medical and industrial literature, oral and written testimony of shoe retailers, newspapers, magazines, and government reports on the uses and dangers of these machines. The public response to shoe-fitting fluoroscopes changed from initial enthusiasm and trust to suspicion and fear, in conjunction with shifting cultural attitudes to radiation technologies.

[Radioscopy and radiography of the thorax. Birth and maturation of an ever-current technique]. / Radioscopie et radiographie du thorax. Naissance et maturation d'une technique toujours d'actualité.

There are three milestones in the history of thoracic radiology. Thoracic radiology started in 1897 when Williams developed thoracic fluoroscopy and introduced the basic concepts of roentgenologic interpretation. At the same time, the first chest films were performed allowing decisive improvement in the diagnosis of many chest diseases. Continuous technical improvement is responsible for the fact that, even today, the conventional chest film remains a highly accurate and frequently used imaging modality. A third milestone was the development of digital radiography and its use in the chest. Computerised tomography changed thoracic imaging dramatically; in a first step mainly as a tool to visualise soft tissue abnormalities and, later on, also as a modality to study lung disease. The recent development of the digital chest radiograph has again added new perspectives to the approach and diagnosis of chest disease.

New Jersey's Thomas Edison and the fluoroscope.

Thomas Edison played a major role in the development of early x-ray technology in 1896, notably increasing tube power and reliability and making the fluoroscope a practical instrument. Eventually, Edison would move x-ray technology from the laboratory to the marketplace.

[Cardiac radiology]. / La radiologie cardiaque.

From the beginning of the era of X-rays, cardiac radiology has become a target of this new technique. Early pioneers, Ciegem, Rieder, Rosenthal, Williams rapidly accumulated extensive experience with fluoroscopy and radiography and publications on cardiac diseases as soon as 1899 and 1901 and 1902. The next step in cardiac diagnosis was achieved by Forsmann in 1929, with the first attempt at cardiac catheterization and angiocardiography. Many clinicians, Moniz, Reboul, Rousthoi contributed to the development of the technique between 1930 and 1940. A further turning point came in 1941 when Cournand demonstrated that cardiac catheterization was a safe method in man. In the technical field major progress came from Scandinavia were rapid filming was born. The management of ischaemic disease, changed dramatically with the demonstration of coronary anatomy, largely due to Sones, Judkins and Amplatz. A further progress was initiated in 1977 by Gruentzig who invented balloon angioplasty.