Radiation Exposure From Diagnostic Imaging in Severely Injured Trauma Patients

Comparison of dose length product and image quality of a biphasic whole-body polytrauma CT protocol with and without the automatic tube voltage selection

BACKGROUND AND AIMS

A significant source of man-made radiation is now linked to medical devices especially X-ray imaging based ones like CT scans which expose the body to cumulative ionizing radiation and thus attendant cancer risks. The aim of this study was to determine whether using a combination of Automatic Tube Current Modulation (ATCM) and Automatic Tube Voltage Selection (ATVS) during two-phase whole-body CT (2PWBCT) examinations would reduce the radiation dose while preserving the image quality.

PATIENTS AND METHODS

This was a prospective, observational, single-centre study of 127 adult patients who had undergone the 2PWBCT polytraumatic protocol. All were examined on a Somatom Drive scanner (Siemens). The patients were divided into two groups: ATCM only (42 patients) and ATCM +ATVS (85 patients). Patients' arm positions during examination and the examination dose length product (DLP) values were recorded, as well the standard deviations (SD) of the density in reference areas on CT scans for the image quality assessment. The DLP values and image quality in the groups were compared using ANOVA.

RESULTS

Mean Total DLP (in mGy*cm): ATCM only: 3337 +/-797, ATCM+ATVS: 3402 +/-830; P=0.674. No effect of arm position (P=0.586). Mean density SD values in reference areas (in HU) in ATCM only: 49 +/-45, 15 +/-6, 9 +/-2, 12 +/-4, 10 +/-3, in ATCM+ATVS: 48 +/-45, 17 +/-6, 11 +/-3, 15 +/-6, 12 +/-4. SD values was higher in ATCM+ATVS group (P<0.001).

CONCLUSION

Combination of ATVS and ATCM in polytraumatic 2PWBCT leads to no significant radiation load reduction compared with ATCM only but does lead to a slight degradation of image quality. The radiation load is significantly reduced if the patient has their arms behind the head when scanning, regardless of the activation of ATVS.

TomoRay: Generating Synthetic Computed Tomography of the Spine From Biplanar Radiographs

OBJECTIVE

Computed tomography (CT) imaging is a cornerstone in the assessment of patients with spinal trauma and in the planning of spinal interventions. However, CT studies are associated with logistical problems, acquisition costs, and radiation exposure. In this proof-of-concept study, the feasibility of generating synthetic spinal CT images using biplanar radiographs was explored. This could expand the potential applications of x-ray machines pre-, post-, and even intraoperatively.

METHODS

A cohort of 209 patients who underwent spinal CT imaging from the VerSe2020 dataset was used to train the algorithm. The model was subsequently evaluated using an internal and external validation set containing 55 from the VerSe2020 dataset and a subset of 56 images from the CTSpine1K dataset, respectively. Digitally reconstructed radiographs served as input for training and evaluation of the 2-dimensional (2D)-to-3-dimentional (3D) generative adversarial model. Model performance was assessed using peak signal to noise ratio (PSNR), structural similarity index (SSIM), and cosine similarity (CS).

RESULTS

At external validation, the developed model achieved a PSNR of 21.139 ± 1.018 dB (mean ± standard deviation). The SSIM and CS amounted to 0.947 ± 0.010 and 0.671 ± 0.691, respectively.

CONCLUSION

Generating an artificial 3D output from 2D imaging is challenging, especially for spinal imaging, where x-rays are known to deliver insufficient information frequently. Although the synthetic CT scans derived from our model do not perfectly match their ground truth CT, our proof-of-concept study warrants further exploration of the potential of this technology.

Patterns of computed tomography utilisation in injury management: latent classes approach using linked administrative data in Western Australia

PURPOSE

Whilst computed tomography (CT) imaging has been a vital component of injury management, its increasing use has raised concern regarding ionising radiation exposure. This study aims to identify latent classes (underlying patterns) of CT use over a 3-year period following the incidence of injury and factors predicting the observed patterns.

METHOD

A retrospective observational cohort study was conducted in 21,544 individuals aged 18 + years presenting to emergency departments (ED) of four tertiary public hospitals with new injury in Western Australia. Mixture modelling approach was used to identify latent classes of CT use over a 3-year period post injury.

RESULTS

Amongst injured people with at least one CT scan, three latent classes of CT use were identified including a: temporarily high CT use (46.4%); consistently high CT use (2.6%); and low CT use class (51.1%). Being 65 + years or older, having 3 + comorbidities, history with 3 + hospitalisations and history of CT use before injury were associated with consistently high use of CT. Injury to the head, neck, thorax or abdomen, being admitted to hospital after the injury and arriving to ED by ambulance were predictors for the temporarily high use class. Living in areas of higher socio-economic disadvantage was a unique factor associated with the low CT use class.

CONCLUSIONS

Instead of assuming a single pattern of CT use for all patients with injury, the advanced latent class modelling approach has provided more nuanced understanding of the underlying patterns of CT use that may be useful for developing targeted interventions.

The Dose Optimization and Evaluation of Image Quality in the Adult Brain Protocols of Multi-Slice Computed Tomography: A Phantom Study

Computed tomography examinations have caused high radiation doses for patients, especially for CT scans of the brain. This study aimed to optimize the radiation dose and image quality in adult brain CT protocols. Images were acquired using a Catphan 700 phantom. Radiation doses were recorded as CTDIvol and dose length product (DLP). CT brain protocols were optimized by varying parameters such as kVp, mAs, signal-to-noise ratio (SNR) level, and Clearview iterative reconstruction (IR). The image quality was also evaluated using AutoQA Plus v.1.8.7.0 software. CT number accuracy and linearity had a robust positive correlation with the linear attenuation coefficient (µ) and showed more inaccurate CT numbers when using 80 kVp. The modulation transfer function (MTF) showed a higher value in 100 and 120 kVp protocols (p < 0.001), while high-contrast spatial resolution showed a higher value in 80 and 100 kVp protocols (p < 0.001). Low-contrast detectability and the contrast-to-noise ratio (CNR) tended to increase when using high mAs, SNR, and the Clearview IR protocol. Noise decreased when using a high radiation dose and a high percentage of Clearview IR. CTDIvol and DLP were increased with increasing kVp, mAs, and SNR levels, while the increasing percentage of Clearview did not affect the radiation dose. Optimized protocols, including radiation dose and image quality, should be evaluated to preserve diagnostic capability. The recommended parameter settings include kVp set between 100 and 120 kVp, mAs ranging from 200 to 300 mAs, SNR level within the range of 0.7-1.0, and an iterative reconstruction value of 30% Clearview to 60% or higher.

Imaging of penetrating vascular trauma of the body and extremities secondary to ballistic and stab wounds

In the United States, gunshot wounds (GSWs) have become a critical public health concern with substantial annual morbidity, disability, and mortality. Vascular injuries associated with GSW may pose a clinical challenge to the physicians in the emergency department. Patients demonstrating hard signs require immediate intervention, whereas patients with soft signs can undergo further diagnostic testing for better injury delineation. Although digital subtraction angiography is the gold standard modality to assess vascular injuries, non-invasive techniques such as Doppler ultrasound, computed tomography angiography, and magnetic resonance angiography have evolved as appropriate alternatives. This article discusses penetrating bodily vascular injuries, specifically ballistic and stab wounds, and the corresponding radiological presentations.

Efficacy of extended focused assessment with sonography for trauma using a portable handheld device for detecting hemothorax in a low resource setting; a multicenter longitudinal study

Introduction

Chest trauma is one of the most important and commonest injuries that require timely diagnosis, accounting for 25–50% of trauma related deaths globally. Although CT scan is the gold standard for detection of haemothorax, it is only useful in stable patients, and remains unavailable in most hospitals in low income countries. Where available, it is very expensive. Sonography has been reported to have high accuracy and sensitivity in trauma diagnosis but is rarely used in trauma patients in low income settings in part due to lack of the sonography machines and lack of expertise among trauma care providers. Chest X-ray is the most available investigation for chest injuries in low income countries. However it is not often safe to wheel seriously injured, unstable trauma patients to X-ray rooms. This study aimed at determining the efficacy of extended focused assessment with sonography for trauma (eFAST) in detection of haemothorax using thoracostomy findings as surrogate gold standard in a low resource setting.

Methods

This was an observational longitudinal study that enrolled 104 study participants with chest trauma. Informed consent was obtained from all participants. A questionnaire was administered and eFAST, chest X-ray and tube thoracotomy were done as indicated. Data were analysed using SPSS version 22. The sensitivity, specificity, predictive values, accuracy and area under the curve were determined using thoracostomy findings as the gold standard. Ethical approval for the study was obtained from the Research and Ethics Committee of Kampala International University Western Campus REC number KIU-2021-53.

Results

eFAST was found to be superior to chest X-ray with sensitivity of 96.1% versus 45.1% respectively. The accuracy was also higher for eFAST (96.4% versus 49.1%) but the specificity was the same at 100.0%. The area under the curve was higher for eFAST (0.980, P = 0.001 versus 0.725, P = 0.136). Combining eFAST and X-ray increased both sensitivity and accuracy.

Conclusion

This study revealed that eFAST was more sensitive at detecting haemothorax among chest trauma patients compared to chest X-ray. All patients presenting with chest trauma should have bedside eFAST for diagnosis of haemothorax.

Changing the Patient's Position: Pitfalls and Benefits for Radiation Dose and Image Quality of Computed Tomography in Polytrauma

For computed tomography (CT), representing the diagnostic standard for trauma patients, image quality is essential. The positioning of the patient’s arms next to the abdomen causes artifacts and is also considered to increase radiation exposure. The aim of this study was to evaluate the effect of various positionings during different CT examination steps on the extent of artifacts as well as radiation dose using iterative reconstruction (IR). 354 trauma-CTs were analyzed retrospectively. All datasets were reconstructed using IR and three different examination protocols were applied. Arm elevation led to a significant improvement of the image quality across all examination protocols (p < 0.001). Variation in arm positioning during image acquisition did not lead to a reduction of radiation dose (p = 0.123). Only elevation during scout acquisition resulted in the reduction of radiation exposure (p < 0.001). To receive high-quality CT images, patients should be placed with elevated arms for the trunk scan, as artifacts remain even with the IR. Arm repositioning during the examination itself had no effect on the applied radiation dose because its modulation refers to the initial scout obtained. In order to achieve a dose effect by different positioning, a two-scout protocol (dual scout) should be used.

Cone-Beam Navigation Can Reduce the Radiation Exposure and Save Fusion Length-Dependent Operation Time in Comparison to Conventional Fluoroscopy in Pedicle-Screw-Based Lumbar Interbody Fusion

This study investigates the advantages and disadvantages of cone-beam-based navigated standardized posterior lumbar interbody fusion surgery (PLIF), regarding the radiation exposure and perioperative time management, compared to the use of fluoroscopy. Patients treated receiving an elective one- to three-level PLIF were retrospectively enrolled in the study. The surgery time, preparation time, operation room time, and effective dose (mSv) were analyzed for comparison of the radiation exposure and time consumption between cone-beam and fluoroscopy; Results: 214 patients were included (108 cone-beam navigated, and 106 traditional fluoroscopies). Using cone-beam navigation, reductions in the effective dose (2.23 ± 1.96 mSv vs. 3.39 ± 2.32 mSv, p = 0.002) and mean surgery time of 30 min (143.62 ± 43.87 min vs. 171.10 ± 48.91 min, p < 0.001) were demonstrated, which leveled out the extended preparation time of 7−8 min (37.25 ± 9.99 min vs. 29.65 ± 7.69 min, p < 0.001). These effects were fusion length dependent and demonstrated additional benefits in multisegmental surgeries. The cone-beam navigation system led to a reduction in the perioperative time requirements and radiation exposure. Furthermore, the controversially discussed longer preparation time when using cone-beam navigation was amortized by a shortened surgery time, especially in multilevel surgery.

Computed tomography with low-dose radiation versus standard-dose radiation for diagnosing fractures: systematic review and meta-analysis

BACKGROUND

Computed tomography (CT) accounts for 13% of all radiological examinations in the United States and 40-70% of the radiation that patients receive. Even with the advent of magnetic resonance imaging (MRI), CT continues to be the gold standard for diagnosing bone fractures. There is uncertainty as to whether CT with a low radiation dose has a fracture detection rate similar to that of standard-dose CT.

OBJECTIVE

To determine the detection rate of low-dose radiation CT and standard-dose radiation CT for fractures, in patients with suspected fractures.

DESIGN AND SETTING

Systematic review of comparative studies on diagnostic accuracy within the evidence-based health program at a federal university in São Paulo (SP), Brazil.

METHODS

We searched the electronic databases Cochrane Library, MEDLINE, EMBASE and LILACS up to June 29, 2020, for studies evaluating the detection rates of low-dose CT and standard-dose CT for diagnosing bone fractures. The Research Triangle Institute (RTI) item bank tool was used for methodological quality evaluation.

RESULTS

The fracture detection rate according to the number of bones evaluated, using CT with low-dose radiation was 20.3%, while with standard-dose radiation it was 19.2%, and the difference between the methods was not significant. The fracture detection rate according to the number of patients, using CT with low-dose radiation was 56.0%, while with standard-dose radiation it was 58.7%, and this difference between the methods was not significant, either.

CONCLUSION

CT with low-dose radiation presented detection rates similar to those of CT with standard-dose radiation, regardless of the bones evaluated.

REGISTRATION NUMBER

CRD42019148491 at the PROSPERO database.

The use of ionising radiation in orthopaedic surgery: principles, regulations and managing risk to surgeons and patients

The use of ionising radiation for plain film radiography and computerised tomography is fundamental in both diagnostics and treatment for orthopaedics. However, radiation is not without risk as high exposure can increase the risk of cancer. Little time is spent educating doctors about the relative risks of radiation, both to patients and themselves. In addition, there are common misunderstandings about the best ways to mitigate such risk. We aim to provide an overview of the fundamental principles of the use of ionising radiation and its risks within the context of orthopaedic surgery. While providing a narrative review of the current literature, we discuss the basic physics, standards of good practice and relevant UK and European regulations. We discuss the risks to patients and surgeons and suggest ways that these can be mitigated in the operating theatre. A thorough understanding of the risks, and appropriate procedural rules, with respect to the use of ionising radiation is essential for those in orthopaedic practice.

Low-dose CT for diagnosing intestinal obstruction and pneumoperitoneum; need for retakes and diagnostic accuracy

Background

One of the main concerns using low-dose (LD) CT for evaluation of patients with suspected intestinal obstruction or pneumoperitoneum is the potential need to make an additional standard-dose (SD) CT scan (retake) due to insufficient diagnostic accuracy of the LD CT.

Purpose

To determine the frequency of retakes and evaluate the diagnostic accuracy of LD CT for the assessment of intestinal obstruction and pneumoperitoneum.

Material and Methods

This retrospective study registered all LD CT scans over a one-year period at Aarhus University Hospital, Denmark in patients with suspected intestinal obstruction or perforation, comprising a total of 643 LD CT scans. A retake was defined as a SD CT scan of the abdomen and pelvis performed with or without intravenous contrast within 72 h after the initial LD CT due to either continued suspicion of intestinal obstruction or perforation or due to unclarified secondary findings. The sensitivity and specificity of LD CT for diagnosing intestinal obstruction and pneumoperitoneum compared to the discharge diagnoses of the scanned patients were determined.

Results

The frequency of retakes was 3%. The overall LD CT sensitivity and specificity for assessment of patients with suspected intestinal obstruction and pneumoperitoneum was 83% and 99%, respectively, but higher in certain subgroups.

Conclusions

LD CT led to few retakes and had a high diagnostic accuracy for diagnosing intestinal obstruction and pneumoperitoneum. Thus, LD CT can be recommended as the examination of choice in patients with suspected intestinal obstruction or perforation in order to reduce radiation dose.

Prediction of impacts on liver enzymes from the exposure of low-dose medical radiations through artificial intelligence algorithms

OBJECTIVES

This study aimed to develop artificial intelligence and machine learning-based models to predict alterations in liver enzymes from the exposure of low annual average effective doses in radiology and nuclear medicine personnel of Institute of Nuclear Medicine and Oncology Hospital.

METHODS

Ninety workers from the Radiology and Nuclear Medicine departments were included. A high-capacity thermoluminescent was used for annual average effective radiation dose measurements. The liver function tests were conducted for all subjects and controls. Three supervised learning models (multilayer precentron; logistic regression; and random forest) were applied and cross-validated to predict any alteration in liver enzymes. The t-test was applied to see if subjects and controls were significantly different in liver function tests.

RESULTS

The annual average effective doses were in the range of 0.07-1.15 mSv. Alanine transaminase was 50% high and aspartate transaminase was 20% high in radiation workers. There existed a significant difference (p=0.0008) in Alanine-aminotransferase between radiation-exposed and radiation-unexposed workers. Random forest model achieved 90-96.6% accuracies in Alanine-aminotransferase and Aspartate-aminotransferase predictions. The second best classifier model was the Multilayer perceptron (65.5-80% accuracies).

CONCLUSION

As there is a need of regular monitoring of hepatic function in radiation-exposed people, our artificial intelligence-based predicting model random forest is proved accurate in prediagnosing alterations in liver enzymes.

Does routine repeat imaging for blunt high-grade renal trauma lead to unnecessary interventions?

BACKGROUND

Most high-grade renal injuries with urinary extravasation (UE) may be managed conservatively without intervention. For such patients, the American Urological Association Urotrauma guidelines recommend repeat imaging within 48 to 72 hours of injury. We sought to examine whether routine, proactive follow-up renal imaging was associated with need for urologic intervention or risk of complications.

METHODS

Patients treated to an urban level 1 trauma center for a five-state region, between 2005 and 2017 were identified by International Classification of Diseases, Ninth Revision and Tenth Revision, codes from a prospectively collected institutional trauma registry. Individual patient charts and imaging were reviewed to identify all patients with American Association for the Surgery of Trauma grade IV renal injuries. Those with UE were included, and patients with penetrating trauma, immediate urologic surgery, or in-hospital mortality were excluded.

RESULTS

Of 342 patients with grade IV injuries, 108 (32%) met the inclusion criteria. Urologic intervention was performed in 23% (25 of 108 patients) including endoscopic procedure (24 of 108 patients) and nephrectomy (1 of 108 patients). Repeat imaging was performed within 48 to 72 hours after initial imaging in 65% (70 to 108 patients). Patients who underwent routine reimaging had a higher rate of undergoing subsequent urologic procedure (31.4% vs. 7.1%, p = 0.008). For patients with reimaging who underwent a procedure, 18% (4 of 22 patients) were symptomatic, while all nonroutinely reimaged patients who underwent a procedure were symptomatic (3 of 3 patients). Patients who received routine repeat imaging had a higher mean number of abdominal computed tomography scans during their admission (2.5 vs. 1.7, p < 0.001), while the complication rate was similar between groups.

CONCLUSIONS

Patients with grade IV renal lacerations with UE from blunt trauma who received routine repeat imaging were more likely to undergo an operation in the absence of symptoms and received more radiation during their hospital stay. Forgoing repeat imaging was not associated with an increase in urological complications. These data suggest that, in the absence of signs/symptoms, repeat imaging may be avoidable.

LEVEL OF EVIDENCE

Therapeutic/care management, level IV.

EFFECTIVE DOSE FOR RADIOLOGICAL PROCEDURES IN AN EMERGENCY DEPARTMENT: A CROSS-SECTIONAL STUDY

The extent of radiation exposure in emergency settings is not well documented; here, the corresponding effective dose (ED) is provided. In 500 patients admitted in row to the emergency department, ED was compared in patients according to complaints and their visiting physicians. Out of all, 220 patients aged 43.5 ± 22.2 years (admission: 2.0 ± 1.6 days) had at least an imaging. The main reasons for admission were trauma (10.5%) and then orthopedic problems (8.6%). EDs from CT and radiography were 1.66 ± 3.59 and 0.71 ± 1.67 mSv, respectively (from all 2.29 ± 4.12). Patients with abdominal (5.8 ± 5.2 mSv; p < 0.002) and pelvic (12.0 ± 6.3 mSv; p < 0.007) complaints received higher ED from CT and radiography and, also, patients visited by surgeons (7.94 ± 6.9 mSv). CT scan was the main source for ED to patients. Irrespective of the final diagnosis, patients with abdominopelvic complaints and those visited by surgeons are at higher exposure risk.

DIAGNOSTIC IMAGING AND IONIZING RADIATION EXPOSURE IN A LEVEL 1 TRAUMA CENTRE POPULATION MET WITH TRAUMA TEAM ACTIVATION: A ONE-YEAR PATIENT RECORD AUDIT

This audit describes ionizing and non-ionizing diagnostic imaging at a regional trauma centre. All 144 patients (males 79.2%, median age 31 years) met with trauma team activation from 1 January 2015 to 31 December 2015 were included. We used data from electronic health records to identify all diagnostic imaging and report radiation exposure as dose area product (DAP) for conventional radiography (X-ray) and dose length product (DLP) and effective dose for CT. During hospitalization, 134 (93.1%) underwent X-ray, 122 (84.7%) CT, 92 (63.9%) focused assessment with sonography for trauma (FAST), 14 (9.7%) ultrasound (FAST excluded) and 32 (22.2%) magnetic resonance imaging. One hundred and sixteen (80.5%) underwent CT examinations during trauma admissions, and 73 of 144 (50.7%) standardized whole body CT (SWBCT). DAP values were below national reference levels. Median DLP and effective dose were 2396 mGycm and 20.42 mSv for all CT examinations, and 2461 mGycm (national diagnostic reference level 2400) and 22.29 mSv for a SWBCT.

Utilization of Computed Tomography in Temporal Bone Fractures at a Large Level I Trauma Center

OBJECTIVES/HYPOTHESIS

To identify which patients with temporal bone fractures who have already undergone trauma pan-scan computed tomography (CT) do not require an additional dedicated temporal bone CT. To determine the added cost of dedicated temporal bone CT in a lower-risk group of patients.

STUDY DESIGN

Retrospective chart review.

METHODS

A chart review was conducted of adult patients at a large level I trauma center with temporal bone fractures who underwent both trauma pan-scan CT and dedicated temporal bone CT. Patients were risk stratified into lower- and higher-risk groups based on imaging and physical exam findings. Imaging findings regarding five critical anatomic structures were compared between the two types of CT scans.

RESULTS

There were 180 patients who met inclusion criteria, with 120 patients stratified to the lower-risk group. The negative predictive values of trauma pan-scan CT within the lower-risk group for fracture involvement with the five critical anatomic structures were as follows: otic capsule (1.000), carotid canal (0.960), facial nerve canal (1.000), ossicular chain (0.992), and tegmen (0.856). The annual out-of-pocket cost to patients for dedicated temporal bone CT imaging in the lower-risk group was estimated to be approximately $34,000, for a total of $190,000 during the complete study period.

CONCLUSIONS

Trauma pan-scan CT may be sufficient in lower-risk patients to identify temporal bone fracture involvement with critical anatomic structures of the temporal bone. Reductions in dedicated temporal bone imaging will decrease both radiation exposure to trauma patients and strain on radiology departments.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E278-E282, 2021.

Cross-sectional imaging of the torso reveals occult injuries in asymptomatic blunt trauma patients

Background

High morbidity and mortality rates of trauma injuries make early detection and correct diagnosis crucial for increasing patient's survival and quality of life after an injury. Improvements in technology have facilitated the rapid detection of injuries, especially with the use of computed tomography (CT). However, the increased use of CT imaging is not universally advocated for. Some advocate for the use of selective CT imaging, especially in cases where the severity of the injury is low. The purpose of this study is to review the CT indications, findings, and complications in patients with low Injury Severity Scores (ISS) to determine the utility of torso CT in this patient cohort.

Methods

A retrospective review of non-intubated, adult blunt trauma patients with an initial GCS of 14 or 15 evaluated in an ACS verified level 1 trauma center from July 2012 to June 2015 was performed. Data was obtained from the hospital's trauma registry and chart review, with the following data included: age, sex, injury type, ISS, physical exam findings, all injuries recorded, injuries detected by torso CT, missed injuries, and complications. The statistical tests conducted in the analysis of the collected data were chi-squared, Fischer exact test, and ANOVA analysis.

Results

There were 2306 patients included in this study, with a mean ISS of 8. For patients with a normal chest exam that had a chest CT, 15% were found to have an occult chest injury. In patients with a negative chest exam and negative chest X-ray, 35% had occult injuries detected on chest CT. For patients with a negative abdominal exam and CT abdomen and pelvis, 16% were found to have an occult injury on CT. Lastly, 25% of patients with normal chest, abdomen, and pelvis exams with chest, abdomen, and pelvis CT scans demonstrated occult injuries. Asymptomatic patients with a negative CT had a length of stay 1 day less than patients without a corresponding CT. No incidents of contrast-induced complications were recorded.

Conclusions

A negative physical exam combined with a normal chest X-ray does not rule out the presence of occult injuries and the need for torso imaging. In blunt trauma patients with normal sensorium, physical exam and chest X-ray, the practice of obtaining cross-sectional imaging appears beneficial by increasing the accuracy of total injury burden and decreasing the length of stay.

Composition and Associated Factors of Radiological Examination in Major Trauma Patients: A Prospective Observational Study

The care of major trauma patients continues to be a challenge for emergency physicians and trauma surgeons. We found that the total number of radiological examinations for major trauma patients in this study was high and mainly comprised radiography and computed tomography (CT), with CT being more commonly adopted. The number of CT scans was positively correlated with severity of injury and intensive care unit length of stay. Further study is warranted to optimize radiological examinations involving major trauma patients.

Prior CT imaging history for patients who undergo whole-body CT for acute traumatic injury and are discharged home from the emergency department

Background

Recurrent CT imaging is believed to significantly increase lifetime malignancy risk. We previously reported that high acuity, admitted trauma patients who received a whole-body CT in the emergency department (ED) had a history of prior CT imaging in 14% of cases. The primary objective of this study was to determine the CT imaging history for trauma patients who received a whole-body CT but were ultimately deemed safe for discharge directly home from the ED.

Methods

This was a retrospective cohort study conducted at an academic ED. All trauma patients who were discharged directly home from the ED after whole-body CT were analyzed. The decision to utilize whole-body CT was at the discretion of the caring physician during the study period. Clinical data for the most recent trauma visit was recorded in a structured fashion on a standardized data collection instrument utilizing the hospital system electronic medical record (EMR). Subsequently, study investigators reviewed a shared, electronic radiological archive for the 6-hospital system to evaluate prior CT exposure for each patient.

Results

165 patients were in the study group. The mean age of the study group was 39+/− 16 years old, 40% were female and 64% were Hispanic. The most common mechanism of injury in our study group was motor vehicle crash (MVC) (66%). In our study group, 25% had at least one prior CT. The most common prior studies performed were: CT abdomen/pelvis (13%), CT head (9.1%), CT face (6.7%), and CT chest (1.8%). Within a multivariate logistic regression model we found that the large majority of patient characteristics and mechanisms of injury were not associated with a positive prior CT imaging history.

Conclusion

We found a positive history for prior CT for 25% of trauma patients who received whole-body CT scan but were discharged from the ED to home.

Whole body computed tomography in multi trauma patients: Review of the current literature

Many authors adopt the Selected Computed Tomography (SCT) approach of the Advanced Trauma Life Support (ATLS) for the management of multiple trauma patients. In the SCT approach, the initial physical examination is followed by conventional radiography (cervical X-ray, chest X-ray, pelvic X-ray and Focused Abdominal Sonography in Trauma (FAST)), and the computed tomography (CT) of the specific body regions if indicated. An alternative to this traditional approach is the Whole-body Computed Tomography (WBCT) protocol, which became widespread all over the world in the last two decades to minimize the rate of missed injuries and decrease the mortality rate.

According to the literature, the WBCT approach is superior to the traditional SCT approach in the time of imaging, diagnostic accuracy, and mortality rates. Conversely, WBCT increases the cancer risk due to additional irradiation. Therefore, it is recommended that the WBCT protocol should be reserved for only severe multi-trauma patients. However, further studies to define severe patients, and clinical decision criteria for WBCT are needed.

Patient Radiation Dose in Neurointerventional Radiologic Procedure: A Tertiary Care Experience

PURPOSE

Neurointerventional radiology procedures often require a long time to perform. Patient radiation dose is an important issue due to the hazards of ionizing radiation. The objective of this study was to measure the peak skin dose (PSD) and effective dose to estimate the deterministic and stochastic effects of a therapeutic interventional neuroradiologic procedure.

MATERIALS AND METHODS

The cumulative dose (CD) and dose area product (DAP) were automatically recorded by a fluoroscopic machine and collected prospectively between April and November 2015. The study included 54 patients who underwent therapeutic neurointerventional radiology procedures. The CD of each patient was used to estimate the peak skin dose and the DAP was also calculated to estimate the effective dose.

RESULTS

The average estimated peak skin dose was 1,009.68 mGy. Two patients received radiation doses of more than 2 Gy, which is the threshold that may cause skin complications and radiation-induced cataract. The average effective dose was 35.32 mSv. The majority of patients in this study (85.2%) who underwent therapeutic neurointerventional radiologic procedures received effective doses greater than 20 mSv.

CONCLUSION

Not all therapeutic neurointerventional radiology procedures are safe from deterministic complications. A small number of patients received doses above the threshold for skin complications and radiation induced cataract. In terms of stochastic complications, most neurointerventional radiology procedures in this study were quite safe in terms of radiation-induced cancer.

Emergency department imaging of pediatric trauma patients during combat operations in Iraq and Afghanistan

BACKGROUND

Military hospitals in Iraq and Afghanistan treated children with traumatic injuries during the recent conflicts. Diagnostic imaging is an integral component of trauma management; however, few published data exist on its use in the wartime pediatric population.

OBJECTIVE

The authors describe the emergency department (ED) utilization of radiology resources for pediatric trauma patients in Iraq and Afghanistan.

MATERIALS AND METHODS

We queried the Department of Defense Trauma Registry (DODTR) for all pediatric patients admitted to military fixed-facility hospitals in Iraq and Afghanistan from January 2007 to January 2016. We retrieved ED data on ultrasound (US), radiographic and computed tomography (CT) studies.

RESULTS

During the study period, there were 3,439 pediatric encounters, which represented 8.0% of all military hospital trauma admissions. ED providers obtained a total of 12,376 imaging studies on 2,920 (84.9%) children. Of the 12,376 imaging studies, 1,341 (10.8%) were US, 4,868 (39.3%) were radiographic and 6,167 (49.8%) were CT exams. Most children undergoing radiographic evaluation were boys (77.8%) and located in Afghanistan (70.4%), and they sustained penetrating injuries (68.0%). Children who underwent imaging had higher composite injury severity scores in comparison to those who did not undergo imaging (10 versus 9).

CONCLUSION

Military health care providers frequently utilized radiographic studies in the evaluation of pediatric trauma casualties in Iraq and Afghanistan. Deployed military hospitals that treat children would benefit from dedicated pediatric-specific imaging training and protocols.

Radiation Exposure From CT Scanning in the Resuscitative Phase of Trauma Care: A Level One Trauma Centre Experience

OBJECTIVES

The initial management of a trauma patient often involves imaging in the form of x-rays, computed tomography (CT) and other radiographic studies, which expose the patient to ionizing radiation, an entity known to cause tissue injury and malignancy at high doses. The purpose of this study was to use a calculation-based method to determine the radiation exposure of trauma patients undergoing trauma team activation in a Canadian tertiary-care trauma centre.

METHODS

A retrospective chart review was conducted using the Nova Scotia Provincial Trauma Registry. All patients age 16 years old and over who underwent trauma team activation between March 1, 2008 and March 1, 2009 were included. Patients who died prior to imaging tests were excluded. Dose reports for each CT were used to calculate a whole-body radiation dose for each patient.

RESULTS

There were 230 trauma team activations during the study period, of which 206 had CT imaging. Data were available for 162 patients. The mean whole-body radiation exposure for all patients was 24.4±10.3 mSv, which may correlate to one additional cancer death for every 100 trauma patients scanned.

CONCLUSIONS

Trauma patients are exposed to significant amounts of radiation during their initial trauma work-up, which may increase the risk of fatal cancer. Clinicians who care for these patients must be aware of the radiation exposure, and take measures to limit radiation exposure of trauma patients.

Risk of Brain Tumor Induction from Pediatric Head CT Procedures: A Systematic Literature Review

Head computed tomography (CT) is instrumental for managing patients of all ages. However, its low dose radiation may pose a low but non-zero risk of tumor induction in pediatric patients. Here, we present a systematic literature review on the estimated incidence of brain tumor induction from head CT exams performed on children and adolescents. MEDLINE was searched using an electronic protocol and bibliographic searches to identify articles related to CT, cancer, and epidemiology or risk assessment. Sixteen studies that predicted or measured head CT-related neoplasm incidence or mortality were identified and reviewed. Epidemiological studies consistently cited increased tumor incidence in pediatric patients (ages 0–18) exposed to head CTs. Excess relative risk of new brain tumor averaged 1.29 (95% confidence interval, 0.66–1.93) for pediatric patients exposed to one or more head CTs. Tumor incidence increased with number of pediatric head CTs in a dose-dependent manner, with measurable excess incidence even after a single scan. Converging evidence from epidemiological studies supported a small excess risk of brain tumor incidence after even a single CT exam in pediatric patients. However, refined epidemiological methods are needed to control for confounding variables that may contribute to reverse causation, such as patients with pre-existing cancer or cancer susceptibility. CT remains an invaluable technology that should be utilized so long as there is clinical indication for the study and the radiation dose is as small as reasonably achievable.

Clinical Predictors of Intra-Abdominal Injury in Severe Blunt Trauma Patient

Introduction

The early recognition of intra-abdominal injury (IAI) in patients with blunt trauma is essential, yet physical examination is often unreliable. Computed tomography (CT) scans are used widely to further evaluate possible IAI but these require time and expense. IAI may be associated with certain objective risk factors or other specific injuries, but this association has not been widely studied. Identification of such risk factors will help to prioritize patients in need for further evaluation of possible IAI.

Methods

A retrospective chart review was conducted of all 622 adult severe blunt trauma patients (Injury Severity Score [ISS] >12) presenting to a level 1 trauma centre in 2004. Various clinical predictors of IAI were analyzed statistically with univariate and multivariate analysis using SAS software.

Results

In multivariate analysis, four significant predictors of IAI were found: positive focused assessment with sonography for trauma (FAST) (OR=48.5, p<0.0001), presence of pelvic fracture (OR=2.4, p=0.0002), chest tube insertion (OR=1.8, p=0.0211), and systolic blood pressure (SBP), where every 10 mmHg decrease indicates a 14% increase in risk (OR=0.986, p=0.001). The absence of all four predictors predicted the absence of IAI with a specificity of 0.776 (95% CI 0.741 to 0.808) and a LR of 2.7 (95% CI 2.0 to 3.5).

Conclusion

This study suggests that positive FAST, presence of pelvic fracture, chest tube insertion, and SBP are significant predictors of IAI in adult blunt trauma patients with ISS > 12. The absence of all four predictors is associated with a reduced risk of IAI.

Complementary exams in blunt torso trauma. Perform only radiographs and fast: is it safe?

OBJECTIVE

to evaluate effectiveness of using chest X-ray (CXR), pelvis X-ray (RXP) and FAST (Focused Abdominal Sonography on Trauma) to exclude significant lesions of the body in blunt trauma.

METHODS

a prospective study involving 74 patients whom made the three tests (CXR, RXP and FAST) during the initial evaluation between October 2013 and February 2014. The results were compared to the tomography of the same patients or clinical outcome. If the patient did not have alterations on the CT scans or during the observation time, the initial workup was considered safe. All patients were evaluated at the Hospital João XXIII, Belo Horizonte, Brazil.

RESULTS

of the 74 patients studied the average age was 33 years, RTS: 6.98, ECG: 12. From 44 (59.45%) patients with exams (radiographs and FAST) unchanged, three had significant injuries (two splenic injuries and one liver injury) diagnosed by clinical monitoring. The remaining patients - 30 (40.55%) - had at least one alteration in conventional tests. Of these group 27 (90%) had significant injuries and three (10%) minor injuries. The sensitivity of all three tests for screening considerable lesions was 90% and the specificity was 93%. The negative predictive value was 93% and the positive predictive value 89%.

CONCLUSION

this research showed that all the three exams - chest X-ray, pelvis and FAST - are safe to lead with the blunt trauma if well used and associated with clinical examination.

Assessing liver proteins and enzymes of medical workers exposed to ionizing radiation (IR)

The cross-sectional study was conducted to examine hepatic function via liver enzymes/proteins assessments, along with the estimation of an inflammatory response from C-reactive protein (CRP)-which is a liver-synthesized protein. The liver function tests with aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and bilirubin (BBN), and CRP test were conducted for radiation-exposed workers-REW (n = 32) and radiation-unexposed workers-RUW (n = 21). The annual average effective doses (AAED) were measured from thermoluminescent dosimeter. A t test and bivariate correlation analyses were applied. Only one worker had a high AST value (50 U/L), one worker had a negligible high ALT value (43 U/L) and only one worker had a negligible high bilirubin value (1.3 g/dL). There were normal levels of CRP (up to 6 mg/L) in all individuals. There existed a nonsignificant difference (p < 0.050) between the mean values of liver enzymes and proteins in all exposed and unexposed workers. Nonsignificant weak correlations are reported in liver enzymes/proteins parameters: AST, ALT, ALP, BBN, CRP with the AAED range (whole-body: 0.91-3.39 mSv) during 2011-2015. The normal values of liver enzymes/proteins' (AST, ALT, ALP, BBN, CRP) values may ensure a good hepatic health of radiation-exposed medical workers with AAED range mentioned. We found that low ionizing radiation doses did not alter the liver function test parameters and did not affect the concentration of an inflammatory response protein, i.e., CRP.

Do clinical guidelines for whole body computerised tomography in trauma improve diagnostic accuracy and reduce unnecessary investigations? A systematic review and narrative synthesis

Introduction

Whole body computerised tomography has become a standard of care for the investigation of major trauma patients. However, its use varies widely, and current clinical guidelines are not universally accepted. We undertook a systematic review of the literature to determine whether clinical guidelines for whole body computerised tomography in trauma increase its diagnostic accuracy.

Materials and methods

A systematic review of Medline, Cinhal and the Cochrane database, supplemented by a manual search of relevant papers was undertaken, with narrative synthesis. Studies comparing clinical guidelines to physician gestalt for the use of whole body computerised tomography in adult trauma were included.

Results

A total of 887 papers were identified from the electronic databases, and 1 from manual searches. Of these, seven papers fulfilled the inclusion criteria. Two papers compared clinical guidelines with routine practice: one found increased diagnostic accuracy while the other did not. Two papers investigated the performance of established clinical guidelines and demonstrated moderate sensitivity and low specificity. Two papers compared different components of established triage tools in trauma. One paper devised a de novo clinical decision rule, and demonstrated good diagnostic accuracy with the tool. The outcome criteria used to define a ‘positive’ scan varied widely, making direct comparisons between studies impossible.

Conclusions

Current clinical guidelines for whole body computerised tomography in trauma may increase the sensitivity of the investigation, but the evidence to support this is limited. There is a need to standardise the definition of a ‘clinically significant’ finding on CT to allow better comparison of diagnostic studies.

Whole body CT versus selective radiological imaging strategy in trauma: an evidence-based clinical review

BACKGROUND

Trauma patients often present with injuries requiring resuscitation and further evaluation. Many providers advocate for whole body computed tomography (WBCT) for rapid and comprehensive diagnosis of life-threatening injuries.

OBJECTIVE

Evaluate the literature concerning mortality effect, emergency department (ED) length of stay, radiation, and incidental findings associated with WBCT.

DISCUSSION

Physicians have historically relied upon history and physical examination to diagnose life-threatening injuries in trauma. Diagnostic imaging modalities including radiographs, ultrasound, and computed tomography have demonstrated utility in injury detection. Many centers routinely utilize WBCT based on the premise this test will improve mortality. However, WBCT may increase radiation and incidental findings when used without considering pre-test probability of actionable traumatic injuries. Studies supporting WBCT are predominantly retrospective and incorporate trauma scoring systems, which have significant design weaknesses. The recent REACT-2 trial randomized trauma patients with high index of suspicion for actionable injuries to WBCT versus selective imaging and found no mortality difference. Additional prospective trials evaluating WBCT in specific trauma subgroups (e.g. polytrauma) are needed to evaluate benefit. In the interim, the available data suggests clinicians should adopt a selective imaging strategy driven by history and physical examination.

CONCLUSIONS

While observational data suggests an association between WBCT and a benefit in mortality and ED length of stay, randomized controlled data suggests no mortality benefit to this diagnostic tool. The literature would benefit from confirmatory studies of the use of WBCT in trauma sub-groups to clarify its impact on mortality for patients with specific injury patterns.

Imaging investigations in Spine Trauma: The value of commonly used imaging modalities and emerging imaging modalities

Traumatic spine injuries can be devastating for patients affected and for health care professionals if preventable neurological deterioration occurs. This review discusses the imaging options for the diagnosis of spinal trauma. It lays out when imaging is appropriate and when it is not. It discusses strength and weakness of available imaging modalities. Advanced techniques for spinal injury imaging will be explored. The review concludes with a review of imaging protocols adjusted to clinical circumstances.

Radiological findings and radiation exposure during trauma workup in a cohort of 1124 level 1 trauma patients

BACKGROUND

During the initial assessment of patients with potential severe injuries, radiological examinations are performed in order to rapidly diagnose clinically relevant injuries. Previous studies have shown that performing these examinations routinely is not always necessary and that trauma patients are exposed to substantial radiation doses. The aim of this study was to assess the amount and findings of radiological examinations during the initial assessment of trauma patients and to determine the radiation doses to which these patients are exposed to.

METHODS

We analyzed the 1124 patients included in a randomized trial. All radiological examinations during the initial assessment (i.e., primary and secondary survey) were assessed. The examination results were categorized as positive findings (i.e., (suspicion for) traumatic injury) and normal findings. The effective radiation doses for the examinations were calculated separately for each patient.

RESULTS

Eight hundred and three patients were male (71 %), median age was 38 years, and 1079 patients sustained blunt trauma (96 %). During initial assessment, almost 3900 X-rays were performed, of which 25.4 % showed positive findings. FAST of the abdomen was performed in 989 patients (88 %), with positive findings in 10.6 %. Additional CT scanning of specific body regions was performed 1890 times in 813 patients (72.1 %), of which approximately 43.4 % revealed positive findings. Hemodynamically stable patients showed more normal findings on the radiographic studies than unstable patients. The mean radiation doses for the total population was 8.46 mSv (±7.7) and for polytraumatized patients (ISS ≥ 16) 14.3 mSv (±9.5).

CONCLUSION

Radiological diagnostics during initial assessment of trauma patients show a high rate of normal findings in our trauma system. The radiation doses to which trauma patients are exposed are considerable. Considering that the majority of the injured patients are hemodynamically stable, we suggest more selective use of X-ray and CT scanning.

Temporal trends in the use of diagnostic imaging for inpatients with pancreatic conditions: How much ionizing radiation are we using?

BACKGROUND

Low-dose ionizing radiation from medical imaging has been indirectly linked with subsequent cancer and increased costs. Computed tomography (CT) is the gold standard for defining pancreatic anatomy and complications. Our primary goal was to identify the temporal trends associated with diagnostic imaging for inpatients with pancreatic diseases.

METHODS

Data were extracted from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample (NIS) database from 2000 to 2008. Pancreas-related ICD-9 diagnostic codes were matched to all relevant imaging modalities.

RESULTS

Between 2000 and 2008, a significant increase in admissions (p < 0.001), but decrease in overall imaging procedures (p = 0.032), for all pancreatic disorders was observed. This was primarily a result of a reduction in the number of CT and endoscopic retrograde cholangiopancreatography examinations (i.e., reduced radiation exposure, p = 0.008). A concurrent increase in the number of inpatient magnetic resonance cholangiopancreatography/magnetic resonance imaging performed was observed (p = 0.040). Intraoperative cholangiography and CT remained the dominant imaging modality of choice overall (p = 0.027).

CONCLUSION

Inpatients with pancreatic diseases often require diagnostic imaging during their stay. This results in substantial exposure to ionizing radiation. The observed decrease in the use of CT may reflect an improved awareness of potential stochastic risks.

The effect of trauma backboards on computed tomography radiation dose

AIM

To assess the effect of trauma backboards on the radiation dose at computed tomography (CT) when using automatic tube current modulation (ATCM).

MATERIALS AND METHODS

An anthropomorphic phantom was scanned with two commercially available CT systems (GE LightSpeed16 Pro and Siemens Definition AS+) without and with backboards. Tube current-time product (mAs), and CTDIvol (mGy) were recorded for each examination. Thermoluminescent dosimeters were used to measure skin entrance dose in the pelvis and breast. Statistical significance was determined using a two-sample t-test. In addition, an institutional review board-approved retrospective image review was performed to quantify the frequency of backboard use during CT in the emergency department.

RESULTS

There was a statistically significant increase in maximum tube current-time product (p<0.05) and CTDIvol (p<0.05) with the presence of a backboard; tube current-time product increased up to 31% and CTDIvol increased up to 27%. There was a significant increase in skin entrance dose in the anterior and posterior pelvis (p<0.05) with the presence of a backboard; skin entrance dose increased up to 25% in the anterior pelvis. Skin entrance dose to the breast increased with a backboard, although this was not statistically significant. The frequency of backboard use during CT markedly decreased (from 77% to 3%) after instituting a multidisciplinary policy to promptly remove patients from backboards upon arrival to the emergency department after a primary clinical survey.

CONCLUSIONS

Using backboards during CT with ATCM can significantly increase the radiation dose. Although the decision to maintain patients on backboards is multifactorial, attempts should be made to minimise backboard use during CT when possible.

Patient and surgeon radiation exposure during spinal instrumentation using intraoperative computed tomography-based navigation

BACKGROUND CONTEXT

Imaging modalities used to visualize spinal anatomy intraoperatively include X-ray studies, fluoroscopy, and computed tomography (CT). All of these emit ionizing radiation.

PURPOSE

Radiation emitted to the patient and the surgical team when performing surgeries using intraoperative CT-based spine navigation was compared.

STUDY DESIGN/SETTING

This is a retrospective cohort case-control study.

PATIENT SAMPLE

Seventy-three patients underwent CT-navigated spinal instrumentation and 73 matched controls underwent spinal instrumentation with conventional fluoroscopy.

OUTCOME MEASURES

Effective doses of radiation to the patient when the surgical team was inside and outside of the room were analyzed. The number of postoperative imaging investigations between navigated and non-navigated cases was compared.

METHODS

Intraoperative X-ray imaging, fluoroscopy, and CT dosages were recorded and standardized to effective doses. The number of postoperative imaging investigations was compared with the matched cohort of surgical cases. A literature review identified historical radiation exposure values for fluoroscopic-guided spinal instrumentation.

RESULTS

The 73 navigated operations involved an average of 5.44 levels of instrumentation. Thoracic and lumbar instrumentations had higher radiation emission from all modalities (CT, X-ray imaging, and fluoroscopy) compared with cervical cases (6.93 millisievert [mSv] vs. 2.34 mSv). Major deformity and degenerative cases involved more radiation emission than trauma or oncology cases (7.05 mSv vs. 4.20 mSv). On average, the total radiation dose to the patient was 8.7 times more than the radiation emitted when the surgical team was inside the operating room. Total radiation exposure to the patient was 2.77 times the values reported in the literature for thoracolumbar instrumentations performed without navigation. In comparison, the radiation emitted to the patient when the surgical team was inside the operating room was 2.50 lower than non-navigated thoracolumbar instrumentations. The average total radiation exposure to the patient was 5.69 mSv, a value less than a single routine lumbar CT scan (7.5 mSv). The average radiation exposure to the patient in the present study was approximately one quarter the recommended annual occupational radiation exposure. Navigation did not reduce the number of postoperative X-rays or CT scans obtained.

CONCLUSIONS

Intraoperative CT navigation increases the radiation exposure to the patient and reduces the radiation exposure to the surgeon when compared with values reported in the literature. Intraoperative CT navigation improves the accuracy of spine instrumentation with acceptable patient radiation exposure and reduced surgical team exposure. Surgeons should be aware of the implications of radiation exposure to both the patient and the surgical team when using intraoperative CT navigation.

Use of advanced imaging techniques during visits to emergency departments--implications, costs, patient benefits/risks

25 years ago, on a Friday evening at 9 pm, the emergency department (ED) was full of patients with a wide range of clinical problems. Their investigations included plain radiographs, but no other imaging was included until the next working day. At present, many patients are receiving advanced imaging such as ultrasound, CT and MRI, often delivered out of hours--an obvious advance for patients or sometimes an unnecessary development? In this article, we will consider how to assess patient benefits and whether increased use of advanced imaging is an overall advance for patients. We will address the general implications for healthcare services which come with greater use of advanced imaging. We will then address the effect of advanced imaging on individual fictional ED patients with a variety of complaints.

Significant but reasonable radiation exposure from computed tomography-related medical imaging in the ICU

Admission to an intensive care unit (ICU) is associated with increased medical imaging and radiation exposure, yet few studies have estimated the risk of cancer associated with these examinations. The purpose of this study was to review computed tomography (CT) scans performed on patients admitted to two urban academic ICUs, predict their radiation exposure, and calculate their estimated lifetime attributable risk of cancer (LAR). An electronic chart review was performed on all CT scans performed between January 2007 and December 2011. The estimated effective dose of radiation was calculated for each CT, and the LAR for each patient was predicted. Mean radiation exposure was 22.2 ± 25.0 mSv with a mean LAR of 0.1 ± 0.2 % and a median of 0.6 % with a range of <0.001 to 3.4 %. Our cohort received radiation doses higher than recommended by guidelines; however, the critical nature of their admission may have warranted these imaging studies. Estimated risk of cancer in this population was overall low.

Optically stimulated luminescence (OSL) response of Al2O3:C, BaFCl:Eu and K2Ca2(SO4)3:Eu phosphors

This paper investigates the optically stimulated luminescence (OSL) response of BaFCl:Eu and K2Ca2(SO4)3:Eu phosphors for different doses and bleaching durations. The results have also been compared with the commercially available Landauer Al2O3:C (Luxel®) dosemeter. Nanocrystalline K2Ca2(SO4)3:Eu is known to be a sensitive thermoluminescent phosphor, but its OSL response is hardly reported. At first, pellets of nanocrystalline K2Ca2(SO4)3:Eu powder were prepared by adding Teflon as a binder. Their OSL signal was compared with that of the material in pure form, i.e. without adding the binder (in 100:1 ratio). It was observed that adding the binder does not appreciably affect the OSL intensity. On comparison with the commercially available Al2O3:C from Landauer, it was found that K2Ca2(SO4)3:Eu is around 15 times less sensitive than Al2O3:C. 'Homemade' BaFCl:Eu phosphor has also been studied. The intensity of BaFCl:Eu was ∼20 times more than the standard Al2O3:C dosemeter and ∼200 times more sensitive than K2Ca2(SO4)3:Eu in the dose range of 13-200 cGy. OSL dosemeters are believed to give luminescence signal even if they are read before, i.e. multiple reading may be possible under suitable conditions after single exposure. This was also checked for all the prepared dosemeters and it was found that Al2O3:C showed the least decrease of <2 %, followed by BaFCl:Eu of 15 % and K2Ca2(SO4)3:Eu with 20 %. Finally, Al2O3:C and BaFCl:Eu phosphors were also studied for their optical bleaching durations to which the respective signals get completely removed so that the phosphor can be re-used. It was observed that BaFCl:Eu is bleached faster and more easily than Al2O3:C.

Complete ultrasonography of trauma in screening blunt abdominal trauma patients is equivalent to computed tomographic scanning while reducing radiation exposure and cost

BACKGROUND

Liberal use of computed tomography of the abdomen and pelvis (CTAP) in the screening of blunt abdominal trauma (BAT) has heightened concerns for increased radiation exposure and costs. We sought to demonstrate that in a select group of BAT patients, complete ultrasonography of trauma (CUST) is equivalent to routine CTAP but with significantly decreased radiation and costs.

METHODS

A retrospective analysis of patients screened for BAT from 2000 to 2011 in a Level 1 trauma center was performed. CUST was available from 8:00 AM to 11:00 PM daily, while CTAP was performed thereafter. Decision to perform CTAP or CUST overnight was made by the attending surgeon based on clinical examination. False negatives (FNs) were described as either a negative CUST or CTAP finding, which later required exploratory laparotomy. Medicare rates and previous data were used for the estimation of cost and radiation exposure.

RESULTS

There were 19,128 patients screened for BAT. A total of 12,577 patients (65.8%) initially underwent CUST, and 6,548 (34.2%) underwent CTAP; 11,059 patients (58% of the total BAT patients) avoided a CTAP, yielding an estimated savings of $6.5 million and 188,003 mSv less radiation during the course of the study. Compared with the CTAP group, patients undergoing CUST had lower Injury Severity Score (ISS) (8.1 vs. 9.6), were older (44.7 years vs. 35.2 years), and experienced less traumatic brain injury (61.4% vs. 69.3%) (all with p < 0.002). Mortality was higher in the CUST group (1.8% vs. 1.2%, p = 0.02), but it was insignificant when adjusted for age older than 65 years (1.1% vs. 0.9%, p = 0.23) or head injury (0.6% and 0.3%, p = 0.4). FN CUST and FN CTAP were 0.29% and 0.1%, respectively (p = nonsignificant), with similar mortality (20% vs. 0%, p = 0.44).

CONCLUSION

CUST is equivalent to routine CTAP for BAT screening and leads to an average of 42% less radiation exposure and more than $591,000 savings per year.

LEVEL OF EVIDENCE

Diagnostic study, level IV; therapeutic/care management study, level IV.

Correlation Between Intra-Abdominal Free Fluid and Solid Organ Injury in Blunt Abdominal Trauma

Background:

In previous studies, the diagnostic value of Focused Assessment with Sonography for Trauma (FAST) has been evaluated but few studies have been performed on the relationship between the amount of free intra-abdominal fluid and organ injury in blunt abdominal trauma. To select patients with a higher probability of intra-abdominal injuries, several scoring systems have been proposed based on the results of FAST.

Objectives:

The aim of this study was to determine the prognostic value of FAST according to the Huang scoring system and to propose a cut-off point for predicting the presence of intra-abdominal injuries on the Computed Tomography (CT) scan. The correlation between age and Glasgow Coma Scale (GCS) and the presence of intra-abdominal injuries on the CT scan was also assessed.

Patients and Methods:

This study was performed on 200 patients with severe blunt abdominal trauma who had stable vital signs. For all patients, FAST-ultrasound was performed by a radiologist and the free fluid score in the abdomen was calculated according to the Huang score. Immediately, an intravenous contrast-enhanced abdominal CT scan was performed in all patients and abdominal solid organ injuries were assessed. Results were analyzed using Kruskal-Wallis test, Mann-Whitney test and ROC curves. The correlation between age and GCS and the presence of intra-abdominal injuries on CT-scan was also evaluated.

Results:

The mean age of the patients was 29.6 ± 18.3 years and FAST was positive in 67% of the subjects. A significant correlation was seen between the FAST score and the presence of organ injury on CT scan (P < 0.001). Considering the cut-off point of 3 for the free fluid score (with a range of 0-8), sensitivity, specificity, positive predictive value and negative predictive value were calculated to be 0.83, 0.98, 0.93, and 0.95, respectively. Age and GCS showed no significant correlation with intra-abdominal injuries.

Conclusions:

It seems that FAST examination for intra-abdominal fluid in blunt trauma patients can predict intra-abdominal injuries with very high sensitivity and specificity. Using the scoring system can more accurately determine the probability of the presence of abdominal injuries with a cut-off point of three.

"Occult" rib fractures diagnosed on computed tomography scan only are still a risk factor for solid organ injury

Introduction:

Prior to the widespread use of computed tomography (CT) scan imaging, lower rib fractures diagnosed on chest X-rays (CXRs) were considered a risk factor for abdominal solid organ injury (ASOI). However, CXRs miss about 50% of the rib fractures that are detected on CT scans. We hypothesized that these “occult” rib fractures would not be predictive for ASOI.

Materials and Methods:

Retrospective review of a level I trauma center's database identified all adult blunt trauma patients (n = 11,170) over a 5-year period. Data were abstracted for demographics, injury severity score, presence of ASOI, extremity, pelvic and spine fractures as well as presence and location of rib fractures.

Results:

Rib fractures correlated with the presence of ASOI, regardless of whether they were diagnosed by CXR or CT scan alone (P < 0.01). Middle (3-7) and lower (8-12) rib fractures, especially, correlated with the presence of ipsilateral ASOI (P < 0.0001).

Discussion:

Although CT scan detects more rib fractures than CXR, rib fractures remain a marker for increased likelihood of ASOI regardless of the modality by which they are diagnosed. Patients with rib fractures also have a greater incidence of spine and pelvic fractures. As the trauma community debates moving away from routine whole-body CT imaging towards a more selective approach, these results suggest that any clinical suspicion of rib fractures, despite a negative CXR, may warrant further investigation.