The evolution of medical imaging: from Geiger counters to MRI--a personal saga

The Global Experiment: How the International Atomic Energy Agency Proved Dosimetry to Be a Techno-Diplomatic Issue

This paper draws attention to the role of the IAEA in shaping radiation dosimetry practices, instrumentation, and standards in the late 1950s and 1960s. It traces the beginnings of the IAEA's radiation dose intercomparison program which targeted all member states and involved the WHO so as to standardize dosimetry on a global level. To standardize dosimetric measurement methods, techniques, and instruments, however, one had to devise a method of comparing absorbed dose measurements in one laboratory with those performed in others with a high degree of accuracy. In 1964 the IAEA thus started to build up what I call the "global experiment," an intercomparison of radiation doses with participating laboratories from many of its member states. To carry out the process of worldwide standardization in radiation dosimetry, I argue, an organization with the diplomatic power and global reach of the IAEA was absolutely necessary. Thus, "global experiment" indicates a novel understanding of the experimental process. What counts as an experiment became governed by a process that was designed and strictly regulated by an international organization; it took place simultaneously in several laboratories across the globe, while experimental data became centrally owned and alienated from those that produced it.

Diagnostic Accuracy of Clinical Tests for Neurogenic and Vascular Thoracic Outlet Syndrome: A Systematic Review

OBJECTIVE

To summarize the evidence on the accuracy of clinical tests to help confirm or refute a diagnosis of thoracic outlet syndrome (TOS).

METHODS

We searched 10 databases (January 1990 to February 2016) using relevant key words and medical subject headings terms. We considered diagnostic test accuracy studies comparing clinical tests for the diagnosis of TOS against a reference test. Cross-sectional, cohort, and case-control studies and randomized controlled trials were included. Risk of bias was appraised using QUADAS-2 and the Quality Appraisal of Reliability Studies checklist. We performed a qualitative synthesis of scientifically admissible studies. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline was used to report findings.

RESULTS

A total of 3932 articles were retrieved. After removal of duplicates, 1767 articles were screened for titles and abstract, leaving 494 articles for full-text review. Ten studies met the eligibility criteria and were assessed for risk of bias, 4 of which were included in the review. None of the included studies used the same index tests when comparing with a gold standard, and quality was poor. High clinical heterogeneity and the use of different comparators prevented from pooling results. Findings suggest that prescribing magnetic resonance imaging during provocative positioning to confirm a diagnosis of TOS may be useful. However, this is associated with a high false-positive rate of venous compression.

CONCLUSION

Little evidence currently supports the validity of clinical tests for the diagnosis of TOS. Future diagnostic accuracy studies should aim to use established methodological criteria and appropriate reporting guidelines to help validate clinical tests for diagnosing patients with TOS.

Preliminary results using patient-specific 3d printed models to improve preoperative planning for correction of post-traumatic tibial deformities with circular frames

BACKGROUND

Preoperative planning for circular external fixators is considered vital towards achieving the best results for complex post-traumatic tibial deformities, and patient-specific 3D printed (3DP) models were used here as a planning aid. The main goal was to investigate the fidelity of the preoperative planning process, by assessing the potential to reduce operative time and determining the need to adjust pre-constructed frames intra-operatively.

PATIENTS AND METHODS

Nine patients (10 limbs) underwent treatment for post-traumatic tibial complications using circular external fixation. These were compared to 10 similar cases where a 3DPM was not used as a pre-operative planning aide (Control group). Patient-specific models of affected bones were printed, and preoperative planning was performed using conventional techniques and Hexapod-assisted software. Detailed planning in a virtual procedure determined osteotomy levels and identified sites for wires and half-pins. The prototype of the external fixator was locked in this optimized configuration, removed from the model, and sterilized prior to the actual procedure.

RESULTS

Nine patients with 10 limbs were treated for complications following tibial fractures. Seven were infected non-unions, and three cases were malunions. For all cases a CT based 3DP model of the full tibia was used in the preoperative planning stage. Image analysis required a mean of 1.7 h, with an average of 14.9 h to 3D print each model. In the control group (without a 3D model), the mean surgical time was 329 min (180-680). The mean surgical time in the 3DPM group was only 172.4 min (72-240), (p = 0.024), reducing the surgery time by 48%. For the 3DPM group it was not necessary to modify the preassembled frame in any case, while in the Control group, the pre-constructed frame required intra-operative modifications in 8 of the 10 cases (p = 0.0007).

CONCLUSION

Using patient-specific 3D models has allowed us to carry out meticulous preoperative planning sessions, eliminating the need to modify or alter the frame assembly in the operating room, saving substantial surgical time and enabling a more precise design of the apparatus. This was especially useful in multiplanar deformities and for the spatial configuration of the foot support, talus ring, and ankle ring.

Increasing disparities between resource inputs and outcomes, as measured by certain health deliverables, in biomedical research

Society makes substantial investments in biomedical research, searching for ways to better human health. The product of this research is principally information published in scientific journals. Continued investment in science relies on society's confidence in the accuracy, honesty, and utility of research results. A recent focus on productivity has dominated the competitive evaluation of scientists, creating incentives to maximize publication numbers, citation counts, and publications in high-impact journals. Some studies have also suggested a decreasing quality in the published literature. The efficiency of society's investments in biomedical research, in terms of improved health outcomes, has not been studied. We show that biomedical research outcomes over the last five decades, as estimated by both life expectancy and New Molecular Entities approved by the Food and Drug Administration, have remained relatively constant despite rising resource inputs and scientific knowledge. Research investments by the National Institutes of Health over this time correlate with publication and author numbers but not with the numerical development of novel therapeutics. We consider several possibilities for the growing input-outcome disparity including the prior elimination of easier research questions, increasing specialization, overreliance on reductionism, a disproportionate emphasis on scientific outputs, and other negative pressures on the scientific enterprise. Monitoring the efficiency of research investments in producing positive societal outcomes may be a useful mechanism for weighing the efficacy of reforms to the scientific enterprise. Understanding the causes of the increasing input-outcome disparity in biomedical research may improve society's confidence in science and provide support for growing future research investments.

Neuroscience-based lie detection: the urgent need for regulation

“Illustration” or “map” are among the most frequently used words for translating the Chinese character tu, a graphic representation of any phenomenon that can be pictured in life and society, whether in traditional China or elsewhere. Investigations of the early role of tu in Chinese culture first set out to answer questions about who produced tu, the background of its originator, and the originator's purpose. How were pictures conceptualized? Interpreted? In examining tu, Chinese scholars stressed the relational aspect of tu and shu (writing) to answer both these questions, as well as to the importance of not robbing an image of its overall beauty and life with too much graphic detail. In the West, specific concepts of technical or scientific illustrations did not exist before the Renaissance. With the coming of that age, technical illustration became a specific branch of knowledge and activity, with its own specific goals and ends.

The early years of single photon emission computed tomography (SPECT): an anthology of selected reminiscences

The origin of SPECT can be found in pioneering experiments on emission tomography performed approximately 50 years ago. This historical review consists of a compilation of first person recollections from nine trailblazing scientists who shaped the early years of SPECT instrumentation during the 1960s and 1970s.

A picture is worth 1000 words, but which 1000?

This chapter provides a brief review of technological capabilities for imaging the brain with an emphasis on functional methods, and explores the range of applications for which they have been used. It then examines the epistemological issues associated with this research. It proposes a set of new dimensions for responsibility to accompany the still-emerging field as it realizes increasingly greater potential, continues to grapple with the technology, and faces unprecedented ethical and social challenges.