Chest radiography: optimization of X-ray spectrum for cesium iodide-amorphous silicon flat-panel detector

PURPOSE: To ascertain the optimum x-ray spectrum for chest radiography with a cesium iodide-amorphous silicon flat-panel detector. MATERIALS AND METHODS: End points for optimization included the ratio of tissue contrast to bone contrast and a figure of merit (FOM) equal to the square of the signal-to-noise ratio of tissue divided by incident exposure to the patient. Studies were conducted with both computer spectrum modeling and experimental measurement in narrow-beam and full-field exposure conditions for four tissue thicknesses (8-32 cm). Three parameters that affect spectra were considered: the atomic number (Z) of filter material (Z = 13, 26, 29, 42, 50, 56, 64, 74, and 82), kilovoltage (from 50 to 150 kVp), and filter thickness (from 0.25 to 2.00 half-value layer [HVL]). RESULTS: Computer modeling and narrow-beam experimental data showed similar trends for the full range of parameters evaluated. Spectrum model results showed that copper filtration at 120 kVp or more was optimum for FOM. The ratio of contrasts showed a trend to be higher with higher kilovoltage and only a minor variation with filter material. Full-field experimental results, which reflect the added contribution of x-ray scatter, differed in magnitude but not trends from the narrow-beam data in all cases except the ratio of contrasts in the mediastinum. CONCLUSION: The best performance overall, including both FOM and ratio of contrasts, was at 120 kVp with 1-HVL copper filtration (0.2 mm). With this beam spectrum and an increase in tube output (ie, milliampere seconds) of about 50%, a chest radiograph can be obtained with image quality approximately equal to that with a conventional spectrum but with about 25% less patient exposure.     

Adolescence spinal epidural abscess with neurological symptoms: case report,a lesson to be re-learnt

Epidural abscess of the spinal column is a rare condition that can be fatal if left untreated. It promptly progresses and can cause neurologic paralysis, urinary retention or cauda equina syndrome. Compromised immune system that occurs in patients with diabetes mellitus, AIDS, chronic renal failure, alcoholism, or cancer is a predisposing factor. It mostly occurs in adults. Here we would like to report a case of spontaneous pyogenic lumbar epidural abscess with neurological deficit diagnosed in a 15 year old boy. We treated this case successfully with surgical microscopic decompression and drainage.     

Introduction to Grayscale Calibration and Related Aspects of Medical Imaging Grade Liquid Crystal Displays

Consistent presentation of digital radiographic images at all locations within a medical center can help ensure a high level of patient care. Currently, liquid crystal displays (LCDs) are the electronic display technology of choice for viewing medical images. As the inherent luminance (and thereby perceived contrast) properties of different LCDs can vary substantially, calibration of the luminance response of these displays is required to ensure that observer perception of an image is consistent on all displays. The digital imaging and communication in medicine (DICOM) grayscale standard display function (GSDF) defines the luminance response of a display such that an observer's perception of image contrast is consistent throughout the pixel value range of a displayed image. The main purpose of this work is to review the theoretical and practical aspects of calibration of LCDs to the GSDF. Included herein is a review of LCD technology, principles of calibration, and other practical aspects related to calibration and observer perception of images presented on LCDs. Both grayscale and color displays are considered, and the influence of ambient light on calibration and perception is discussed.     

Most patients are eligible for an alternative to conventional whole breast irradiation for early‐stage breast cancer: A National Cancer Database Analysis

We evaluated the proportion of patients eligible for alternatives to standard whole breast irradiation (WBI) following breast‐conserving surgery using the National Cancer Database (NCDB). Using the 2016 dataset, Stage I‐III patients were identified. Eligibility for hypofractionated WBI (HFRT), accelerated partial breast irradiation (APBI) and endocrine therapy (ET‐alone) was defined using eligibility from large clinical trials as well as consensus guidelines. For patients with pN0 breast cancer, 20.6% and 37.0% were eligible for ET‐alone based on the CALGB 9343/PRIME‐II trials, respectively. In terms of HFRT, 72.5% and 50.4% were eligible based on IMPORT LOW/ASTRO HFRT guidelines, respectively. Based on IMPORT LOW/GEC‐ESTRO trial/ASTRO guidelines/ABS guidelines/GEC‐ESTRO guidelines, 72.5%, 86.1%, 39.0%, 72.5%, 45.7%, respectively, were eligible for APBI. Of those who qualify for HFRT per ASTRO guidelines, approximately 90% were eligible for APBI and 50% for ET‐alone. This analysis shows that a large proportion of patients with node‐negative breast cancer are eligible for HFRT, APBI and/or ET‐alone after breast‐conserving surgery.     

Staging Systems for Newly Diagnosed Myeloma Patients Undergoing Autologous Hematopoietic Cell Transplantation: The Revised International Staging System Shows the Most Differentiation between Groups

The Revised International Staging System (R-ISS) and the International Myeloma Working Group 2014 (IMWG 2014) are newer staging systems used to prognosticate multiple myeloma (MM) outcomes. We hypothesized that these would provide better prognostic differentiation for newly diagnosed multiple myeloma (MM) compared with ISS. We analyzed the Center for International Blood and Marrow Transplant Research database from 2008 to 2014 to compare the 3 systems (N?=?628) among newly diagnosed MM patients undergoing upfront autologous hematopoietic cell transplantation (AHCT). The median follow-up of survivors was 48 (range, 3 to 99) months. The R-ISS provided the greatest differentiation between survival curves for each stage (for overall survival [OS], the differentiation was 1.74 using the R-ISS, 1.58 using ISS, and 1.60 using the IMWG 2014) . Univariate analyses at 3 years for OS showed R-ISS I at 88% (95% confidence interval [CI], 83% to 93%), II at 75% (95% CI, 70% to 80%), and III at 56% (95% CI, 3% to 69%; P < .001). An integrated Brier score function demonstrated the R-ISS had the best prediction for PFS, though all systems had similar prediction for OS. Among available systems, the R-ISS is the most optimal among available prognostic tools for newly diagnosed MM undergoing AHCT. We recommend that serum lactate dehydrogenase and cytogenetic data be performed on every MM patient at diagnosis to allow accurate prognostication.     

Long-term results of endovascular repair for descending thoracic aortic aneurysms

Objective

Since thoracic endovascular aortic repair (TEVAR) received U.S. Food and Drug Administration approval for the treatment of descending thoracic aneurysms in March 2005, excellent 30-day and midterm outcomes have been described. However, data on long-term outcomes are lacking with Medicare data suggesting that TEVAR has worse late survival compared with open descending repair. As such, the purpose of this study was to examine the long-term outcomes for on-label use of TEVAR for repair of descending thoracic aneurysms.