Shima Aran

Current status of nephrogenic systemic fibrosis

Nephrogenic systemic fibrosis (NSF) occurs in patients with advanced chronic kidney disease (CKD) or acute renal failure, most commonly following exposure to gadolinium-based contrast agents (GBCAs). NSF can be debilitating and associated with increased mortality. The putative association of NSF with GBCAs prompted the development of guidelines to limit the use of these contrast agents in at-risk patients. Indeed, the incidence of NSF has decreased dramatically following application of these guidelines, which appears to be the only effective means of decreasing NSF incidence. Thus, increasing clinician awareness of these updated guidelines is important. The present review introduces and compares updated guidelines for GBCA use and discusses the latest advances in the understanding of the pathogenic mechanisms and treatment of NSF.

Dual-energy computed tomography (DECT) in emergency radiology: basic principles, techniques, and limitations.

Recent advances in computed tomography (CT) technology allow for acquisition of two CT datasets with different X-ray spectra. There are different dual-energy computed tomography (DECT) technical approaches such as: the dual-source CT, the fast kilovoltage-switching method, and the sandwich detectors technique. There are various postprocessing algorithms that are available to provide clinically relevant spectral information. There are several clinical applications of DECT that are easily accessible in the emergency setting. In this review article, we aim to provide the emergency radiologist with a discussion on how this new technology works and how some of its applications can be useful in the emergency room setting.

Applications of Dual-Energy CT in Emergency Radiology

OBJECTIVE Recent technologic advances in MDCT have led to the introduction of dual-energy CT (DECT). The basic principle of DECT is to acquire images at two different energy levels simultaneously and to use the attenuation differences at these different energy levels for deriving additional information, such as virtual monochromatic images, artifact suppression, and material composition of various tissues. CONCLUSION A variety of image reconstruction and postprocessing techniques are available for better demonstration and characterization of pathologic abnormalities. DECT can provide both anatomic and functional information of different organ systems. This article focuses on the main applications of DECT in emergency radiology.

Effect of pirfenidone on pulmonary fibrosis due to paraquat poisoning in rats

Background. This study investigated the effectiveness of pirfenidone compared with antioxidants, in the prevention of pulmonary fibrosis and increasing the survival in acutely paraquat poisoned rats. Methods. Five groups of ten rats were included in this study. Three groups were poisoned with intraperitoneal injection of 15 mg/kg paraquat. Among these poisoned groups, one group was treated with vitamin C (500 mg/kg, intraperitoneal), vitamin E (200 mg/kg, intraperitoneal) and N-acetylcysteine (250 mg/kg, intravenous); two others were treated with either normal saline or pirfenidone (200 mg/kg, intravenous); two groups were not poisoned and received normal saline or pirfenidone (200 mg/kg, intravenous). All injections except paraquat were repeated in four consecutive days. On the 15th day of study a semi-quantitative determination of lung fibrosis was done using Ashcroft staging criteria on the lung sections. Results. Pirfenidone decreased paraquat induced lung fibrosis (p < 0.001) while antioxidants did not decrease the lung fibrosis (p = 0.413). Life expectancy decreased in paraquat + normal saline (11 days, 95% CI 7.94–14.05) and paraquat + antioxidant (11 days, 95% CI 7.77–14.23) groups. The increase in the survival of rats in paraquat/pirfenidone group was insignificant (13.4 days, 95% CI 11.13–15.67). Conclusion. This study showed that pirfenidone is able to decrease pulmonary fibrosis following paraquat poisoning in a rat model.

Simulation-Based Training in Radiology

Although the apprenticeship model of medical training has been in use for centuries, there are several problems with its use. The fundamental ethical principle of nonmaleficence requires that no preventable harm come to patients involved in the training process. In addition, changing medical practice patterns with shorter hospital stays and duty-hour restrictions are making it difficult for trainees to be exposed to enough patients to prepare them to deal with the many possible scenarios they may face in practice. Despite these limitations, the apprenticeship model cannot be completely rejected because it is essential for trainees to perfect their technique by caring for real patients with the guidance of experienced practitioners. Simulation-based training can allow novices to learn from their mistakes in a safe environment and in accordance with the principles of deliberate practice, thus allowing simulation to be a bridge to help get trainees from the novice state, in which they have a higher risk of causing harm, to a more experienced state in which they are more likely to do what is needed for patients.

Effect of localizer radiograph on radiation dose associated with automatic exposure control: human cadaver and patient study.

Purpose To evaluate the effect of localizing radiograph on computed tomography (CT) radiation dose associated with automatic exposure control with a human cadaver and patient study. Materials and Methods Institutional review board approved the study with a waiver of informed consent. Two chest CT image series with fixed tube current and combined longitudinal-angular automatic exposure control (AEC) were acquired in a human cadaver (64-year-old man) after each of the 8 combinations of localizer radiographs (anteroposterior [AP], AP lateral, AP-posteroanterior [PA], lateral AP, lateral PA, PA, PA-AP, and PA lateral). Applied effective milliampere second, volume CT dose index (CTDIvol) and image noise were recorded for all 24-image series. Volume CT dose indexes were also recorded in 20 patients undergoing chest and abdominal CT after PA and PA-lateral radiographs with the use of AEC. Data were analyzed using analysis of variance and linear correlation tests. Results With AEC, the CTDIvol fluctuates with the number and projection of localizer radiographs (P < 0.0001). Lowest CTDIvol values are seen when 2 orthogonal localizer radiographs are acquired, whereas highest values are seen when single PA or AP-PA projection localizer radiographs are acquired for planning (P < 0.0001). In 20 patients, CT scanning with AEC after acquisition of 2 orthogonal projection localizer radiographs was associated with significant reduction in radiation dose compared to PA projection radiographs alone (P < 0.0001). Conclusions When scanning with AEC, acquisition of 2 orthogonal localizer radiographs is associated with lower CTDIvol compared to a single localizer radiograph.

Outpatient falls prevention program outcome: an increase, a plateau, and a decrease in incident reports.

OBJECTIVE We implemented an outpatient falls guideline in 2008 in the department of radiology. Here, we describe our multiyear experience. MATERIALS AND METHODS This was a retrospective study conducted between April 2006 and September 2013 to investigate outpatient falls. The span of the study was divided into eight periods. The incident reporting system was searched for the falls and the fall-related variables. RESULTS A total of 327 falls occurred during 5,080,512 radiology examinations (rate, 0.64/10,000 total examinations). The highest rate was in period 6 (0.83/10,000 examinations). The average for periods 1 and 2 is 0.39/10,000 examinations (37 falls/945,427 examinations), and the average for periods 3-6 is 0.77/10,000 examinations (204 falls/2,656,805 examinations). The average rate for periods 7 and 8 is 0.58/10,000 examinations (86 falls/1,478,280 examinations). There was a statistically significant increase in the total number of falls reported between period 2 and period 3 (p = 0.02). There was a statistically significant decrease in outpatient falls between period 6 and period 7 (p = 0.01). The number of falls among patients 60 years old or older was 177 falls/2,180,093 examinations (rate, 0.81/10,000 examinations), and that among patients younger than 60 years was 150 falls/2,900,419 examinations (rate, 0.52/10,000 examinations), with a statistically significant difference (p = 0.007). Although the rate of falls was higher among female patients, there was no statistically significant difference between the sexes (p = 0.18). CONCLUSION The outcome of the outpatient falls guideline was characterized by an increase, a plateau, and a decrease in incident reports. The initial increase may be due to the Hawthorne effect. The plateau may represent the value closest to the true incidence. The decrease may represent the effect of the program.

Dual-Energy Computed Tomography Characterization of Urinary Calculi: Basic Principles, Applications and Concerns.

Dual-energy computed tomography (DECT) is based on obtaining 2 data sets with different peak kilovoltages from the same anatomical region, and material decomposition based on attenuation differences at different energy levels. Several DECT technologies are available such as: the dual-source CT, the fast kilovoltage-switching method, and the sandwich detectors technique. Calculi are detectable using iodine subtraction techniques. DECT also helps characterization of renal stone composition. The advanced postprocessing application enables differentiation of various renal stone types. Calculation of water content using spectral imaging is useful to diagnose urinary obstruction.

Contrast Media Extravasation of Computed Tomography and Magnetic Resonance Imaging: Management Guidelines for the Radiologist

Intravenous contrast administration has been of great importance in diagnostic radiology, but it is not without risks either due to the local, systemic allergic reactions or due to subcutaneous extravasation of contrast media. Subcutaneous contrast medium extravasationis an infrequent, yet a well-recognized complication. However, most incidents are minor and can be managed conservatively, but there are a few cases that require immediate surgical intervention. This article discusses the risks factors, clinical manifestations, and conservative and surgical approaches of subcutaneous contrast media extravasation for both computed tomography and magnetic resonance imaging.

Key Performance Indicators in Radiology: You Can't Manage What You Can't Measure.

Quality assurance (QA) is a fundamental component of every successful radiology operation. A radiology QA program must be able to efficiently and effectively monitor and respond to quality problems. However, as radiology QA has expanded into the depths of radiology operations, the task of defining and measuring quality has become more difficult. Key performance indicators (KPIs) are highly valuable data points and measurement tools that can be used to monitor and evaluate the quality of services provided by a radiology operation. As such, KPIs empower a radiology QA program to bridge normative understandings of health care quality with on-the-ground quality management. This review introduces the importance of KPIs in health care QA, a framework for structuring KPIs, a method to identify and tailor KPIs, and strategies to analyze and communicate KPI data that would drive process improvement. Adopting a KPI-driven QA program is both good for patient care and allows a radiology operation to demonstrate measurable value to other health care stakeholders.