Natural Radioactivity in Raw Building Materials for Underground Parking Lots and Assessment of Radiological Health Risk for the Population.

This article reports the results of an investigation into the activity concentration of natural radionuclides in raw building materials for underground parking lots, together with the assessment of the radiation hazard for the public related to exposure to ionizing radiations. To this purpose, high-purity germanium (HPGe) γ-ray spectrometry was employed in order to quantify the average specific activity of 226Ra, 232Th, and 40K natural radioisotopes. With the aim to assess any possible radiological health risk for the population, the absorbed γ-dose rate (D), the annual effective dose equivalent outdoor (AEDEout) and indoor (AEDEin), the activity concentration index (I), and the alpha index (Iα) were also estimated, resulting in values that were lower than the maximum recommended ones for humans. Finally, the extent of the correlations existing between the observed radioactivity and radiological parameters and of these parameters with the analyzed samples was quantified through statistical analyses, including Pearson's correlation, a principal component analysis (PCA), and a hierarchical cluster analysis (HCA). As a result, three clusters of the investigated samples were recognized based on their chemical composition and mineralogical nature. Noteworthily, this paper covers a certain gap in science since its topic does not appear in literature in this form. Thus, the authors underline the importance of this work to global knowledge in the environmental research and public health fields.

Evaluation of natural radioactivity in soils of Konya (Turkey) and estimation of radiological health hazards.

Surface soil samples were collected from Konya, Turkey and natural activity concentrations were determined using the ɤ-ray spectroscopy system with HPGe detector. The activity concentrations of 226Ra, 232Th and 40K were found to vary from 14.07 ± 0.71 Bq kg-1 dw to 67.27 ± 1.62 Bq kg-1 dw, 10.19 ± 2.60 Bq kg-1 dw to 46.09 ± 0.76 Bq kg-1 dw and 107.87 ± 13.32 Bq kg-1 dw to 605.95 ± 11.34 Bq kg-1 dry weight (dw), respectively. The radiological hazard parameters such as Raeq, D, AEDE, ELCR, AGDE, Hex, Hin, and Iɤ evaluated the radiological risk for the public and environment. The mean values of D, AEDE and ELCR are lower than the world average value of 57 nGy h-1, 70 µSv y-1, 0.29 × 10-3 respectively. The activity concentration distribution maps of 226Ra, 232Th and 40K and the radiological maps of the radiological hazard parameters were plotted using the Surfer programme. Cluster analysis was carried out to indicate the similarity between the variables.

Propuesta metodológica para el uso del programa PCXMC 2.0 en modalidad rotacional / Methodological Proposal for the use of the program PCXMC 2.0 in Rotational Mode

RESUMEN Durante los procedimientos intervencionistas que utilizan fluoroscopia, se entrega a los pacientes diferentes niveles de dosis de radiación, que pueden tener un impacto a corto, mediano o largo plazo, así como en su severidad. Esto en función del tipo de radiación utilizada y de la sensibilidad a la radiación del tipo(s) de órgano(s) irradiado, es en este punto que se vuelve determinante conocer la dosis a órganos entregada durante los procedimientos con el fin de asegurar el bienestar de los pacientes, este procedimiento no se puede realizar directamente en los órganos del paciente, por lo que se utilizan programas especializado en cálculos dosimétricos. El software PCXMC 2.0 logra estimar la dosis efectiva a través del método determinístico Monte Carlo, a su vez, agregando la dosis equivalente y evaluación de riesgo para estudios dosimétricos, por lo cual, el objetivo del presente trabajo fue proponer una metodología estandarizada para la utilización del programa PCXMC en el cálculo de estas dos magnitudes

ABSTRACT During interventional procedures that utilize fluoroscopy, patients are exposed to varying levels of radiation doses, which can have short, medium, or long term impacts, as well as varying severities. This depends on the type of radiation used and the radiation sensitivity of the organ(s) being irradiated. At this point, it becomes crucial to determine the organ doses delivered during procedures in order to ensure patient well-being. Since direct measurements cannot be made on the patient's organs, specialized software is used for dosimetric calculations. PCXMC 2.0 software achieves the estimation of effective dose through the deterministic Monte Carlo method, while also incorporating equivalent dose and risk assessment for dosimetric studies. Therefore, the objective of this work was to propose a standardized methodology for the use of the PCXMC 2.0 sofware in the calculation of these two magnitudes.it is important to outline a working method for this software and provide instructions on its operation

Radiological health assessment of infant milk in Erbil Governorate, Iraq.

In this research, the radioactivity caused by natural radionuclides (40 K, 232Th, and 226Ra) was evaluated in infant milk consumed in Erbil, Iraq. The measurements were performed using an HPGe gamma-ray spectrometer. The variation of activity concentrations in milk samples was (99.56-256.9 Bq kg-1) for 40 K, (BDL-0.53 Bq kg-1) for 232Th, and (0.27-5.59 Bq kg-1) for 226Ra, as determined by the results. The radiological parameters of Eing, Dorg, and ELCR were calculated and compared to international standards. The correlation between computed radiological hazard parameters and natural radionuclides was analyzed statistically using Pearson's correlation. Overall, the results indicate that infant milk consumption in Erbil is radiologically safe and that consumers of these brands of milk are unlikely to be directly exposed to radiological health risks.

Distribution of Radionuclides and Radiological Health Assessment in Seih-Sidri Area, Southwestern Sinai.

The current contribution goal is to measure the distribution of the radionuclide within the exposed rock units of southwestern Sinai, Seih-Sidri area, and assess the radiological risk. Gneisses, older granites, younger gabbro, younger granites, and post granitic dikes (pegmatites) are the main rock units copout in the target area. Radioactivity, as well as radiological implications, were investigated for forty-three samples from gneisses (seven hornblende biotite gneiss and seven biotite gneiss), older granites (fourteen samples), and younger granites (fifteen samples of syenogranites) using NaI (Tl) scintillation detector. External and internal hazard index (Hex, Hin), internal and external level indices (Iα, Iγ), absorbed dose rates in the air (D), the annual effective dose equivalent (AED), radium equivalent activity (Raeq), annual gonadal dose (AGDE), excess lifetime cancer risk (ELCR), and the value of Upper Continental Core 232Th/238U mass fractions were determined from the obtained values of 238U, 232Th and 40K for the examined rocks of Seih-Sidri area. The average 238U mg/kg in hornblende biotite gneiss and biotite gneiss, older granites, and syenogranites is 2.3, 2.1, 2.7, and 8.4 mg/kg, respectively, reflecting a relatively higher concentration of uranium content in syenogranites. The results suggest that using these materials may pose risks to one's radiological health.

Evaluation of Radiological Health Risks in Popularly Consumed Brands of Sachet Water in Nigeria.

Radiological investigation of 35 brands of most popularly used sachet drinking water in Ondo state, Nigeria has been carried out using a spectrometric method for evaluating the concomitant health risks to the members of the public. Activity concentrations of the investigated radionuclides 40K, 226R, and 228Ra were in the range from 16.35 ± 4.10 to 199.94 ± 38.40 Bq L-1 with an arithmetic mean (AM) of 66.22 ± 54.99 Bq L-1, from 1.35± 0.79 to 17.06 ± 5.13 Bq L-1 with an AM of 6.88 ± 3.66 Bq L-1, and from 1.95 ± 0.08 to 17.22 ± 3.87 Bq L-1 with an AM of 9.49 ± 4.98 Bq L-1, respectively. The determined annual effective doses and the corresponding excess lifetime cancer risks due to 226Ra and 228Ra were found to exceed the acceptable limits of 0.1 mSv y-1 and 10-3 respectively, as suggested by the World Health Organization (WHO). This implies a non-negligible carcinogenic health hazard due to the intake of the surveyed drinking water, especially for the lactating babies (0-1) y and teenagers (12-17) y. The data from this research may form an invaluable component of radiometric values of the database in Nigeria, as well as the world for setting up guidelines and control policies for the use of sachet water.

Assessment of the Radiological Health Risk Due to the 226Ra Content in Drinking Water from the Calabria Region, Southern Italy.

In this article, the authors report experimental results obtained for the assessment of the 226Ra content in 80 drinking water samples from the Calabria region, Southern Italy. The activity concentration, measured with the Perkin Elmer Tricarb 4910 TR Liquid Scintillation Counter (LSC) setup, was compared with the reference values reported in the Italian Legislative Decree 28/2016 in order to evaluate any possible radiological health hazards for the population in terms of 226Ra content due to the ingestion of the investigated drinking water. The obtained results put in evidence that the average 226Ra specific activity is lower than the LSC minimum detectable activity (MDA) in all cases, thus, excluding any radiological risk. They also represent the main reference for the investigated area and can be used as a baseline to extend this investigation to the whole region.

Fluoroless Ureteroscopy: Experience in More Than 100 Patients.

BACKGROUND: Ureteroscopy is becoming the primary treatment for ureteral stones. As a standard of care, ureteroscopy is performed under the supervision of fluoroscopy. Recent advances in endourological technology make the need for fluoroscopy questionable. OBJECTIVES: To summarize our experience with a no-fluoroscopy technique for selected cases of ureteral stones. METHODS: Patients were considered suitable for fluoroless ureteroscopy if they had one or two non-impacted stones, in any location in the ureter, 5-10 mm size, with a normal contralateral renal unit and no urinary tract infection. Procedures were performed using rigid scopes, nitinol baskets/forceps for stone retrieval, and Holmium:YAG laser for lithotripsy. Stents were placed per surgeon's decision. RESULTS: During an 18-month period, 103 patients underwent fluoroless ureteroscopy. In 94 patients stones were removed successfully. In six, the stones were pushed to the kidney and treated successfully on a separate session by shock wave lithotripsy. In three patients no stone was found in the ureter. In five patients, miniature perforations in the ureter were noted and an indwelling double J stent was placed. CONCLUSIONS: Fluoroless ureteroscopy resulted in a high rate of success. We believe that in selected cases it can be used with minimal adverse events.

Chemical, biological, radiological, and nuclear mass casualty medicine: a review of lessons from the Salisbury and Amesbury Novichok nerve agent incidents.

On March 4, 2018, two casualties collapsed on a park bench in Salisbury, Wiltshire, UK. They were later discovered to have been the victims of an attempted murder using the Soviet-era Novichok class of nerve agent. The casualties, along with three further critically ill patients, were cared for in Salisbury District Hospital's Intensive Care Unit. Before the COVID-19 pandemic, the Salisbury and Amesbury incidents were the longest-running major incidents in the history of the UK National Health Service. This narrative review seeks to reflect on the lessons learned from these chemical incidents, with a particular focus on hospital and local organisational responses.

Neonatal digital chest radiography- should we be using additional copper filtration?

OBJECTIVES: Copper filtration removes lower energy X-ray photons, which do not enhance image quality but would otherwise contribute to patient radiation dose. This study explores the use of additional copper filtration for neonatal mobile chest imaging. METHODS: A controlled factorial-designed experiment was used to determine the effect of independent variables on image quality and radiation dose. These variables included: copper filtration (0 Cu, 0.1 Cu and 0.2 Cu), exposure factors, source-to-image distance and image receptor position (direct / tray). Image quality was evaluated using absolute visual grading analysis (VGA) and contrast-to-noise ratio (CNR) and entrance surface dose (ESD) was derived using an ionising chamber within the central X-ray beam. RESULTS: VGA, CNR and ESD significantly reduced (p < 0.01) when using added copper filtration. For 0.1 Cu, the percentage reduction was much greater for ESD (60%) than for VGA (14%) and CNR (20%), respectively. When compared to the optimal combinations of parameters for incubator imaging using no copper filtration, an increase in kV and mAs when using 0.1-mm Cu resulted in better image quality at the same radiation dose (direct) or, equal image quality at reduced dose (in-tray). The use of 0.1-mm Cu for neonatal chest imaging with a corresponding increase in kV and mAs is therefore recommended. CONCLUSION: Using additional copper filtration significantly reduces radiation dose (at increased mAs) without a detrimental effect on image quality. ADVANCES IN KNOWLEDGE: This is the first study, using an anthropomorphic phantom, to explore the use of additional Cu for digital radiography neonatal chest imaging and therefore helps inform practice to standardise and optimise this imaging examination.

Responsible Radionuclide Cancer Care.

The landscape of nuclear oncology is rapidly changing. The advent of molecular radionuclide theranostics, multidisciplinary tumor board decision making, artificial intelligence and radiomics interpretation of diagnostic imaging, evolution of pharmacogenomics prediction of tumor response, and regulatory requirements for prospective individual dosimetry are just some of the elements which are broadening the essence of physician responsibility. The burgeoning knowledge base essential for mastering the emergent technologies, and their profound effect on moral philosophic aspects of provision of cancer care, are challenging. The new relationship of the theranostic nuclear physician with respect to shared care of the individual patient, particularly with regard to transparency, accountability, and responsibility for targeted radionuclide diagnosis and therapy of cancer, will be explored in this update.

Measuring Patient Preferences at the FDA Center for Devices and Radiological Health: Reflections and Projections.

OBJECTIVES: Patient preference information (PPI) is a way to incorporate the patient voice in the evaluation of medical devices. The US Food and Drug Administration (FDA) Center for Devices and Radiological Health (CDRH) has been working to encourage the voluntary inclusion of PPI throughout the medical device lifecycle for nearly a decade. This article reflects CDRH's efforts to encourage collection of PPI and offers perspectives on the future of PPI in the evaluation of medical devices. METHODS: CDRH regulatory guidance, public meetings, and collaborations relating to PPI were explored. RESULTS: Since 2012 when CDRH issued guidance on how PPI can be used as scientific evidence in the benefit-risk regulatory submission, CDRH has issued 5 subsequent guidance documents expanding on the use of PPI in medical device evaluations. CDRH remains committed to advancing the science and application of PPI in the medical device ecosystem through many collaborations with professional organizations, patient advocacy groups, and academic institutions. By hosting and actively participating in multiple scientific and regulatory public meetings and conferences, CDRH fosters a continuous learning environment where the experience of using PPI in regulatory submissions can be shared. A September 2020 meeting cosponsored by FDA and International Society for Pharmacoeconomics and Outcomes Research (ISPOR) discussed the state of PPI in regulatory applications and beyond. CONCLUSION: This article describes these pivotal events that have helped to increase the use of PPI in medical device evaluation as well as discusses future applications of PPI.

Executive Summary: Screening for Lung Cancer: Chest Guideline and Expert Panel Report.

BACKGROUND: Low-dose chest CT screening for lung cancer has become a standard of care in the United States, in large part because of the results of the National Lung Screening Trial (NLST). Additional evidence supporting the net benefit of low-dose chest CT screening for lung cancer, and increased experience in minimizing the potential harms, has accumulated since the prior iteration of these guidelines. Here, we update the evidence base for the benefit, harms, and implementation of low-dose chest CT screening. We use the updated evidence base to provide recommendations where the evidence allows, and statements based on experience and expert consensus where it does not. METHODS: Approved panelists reviewed previously developed key questions using the Population, Intervention, Comparator, Outcome format to address the benefit and harms of low-dose CT screening, and key areas of program implementation. A systematic literature review was conducted using MEDLINE via PubMed, Embase, and the Cochrane Library on a quarterly basis since the time of the previous guideline publication. Reference lists from relevant retrievals were searched, and additional papers were added. Retrieved references were reviewed for relevance by two panel members. The quality of the evidence was assessed for each critical or important outcome of interest using the Grading of Recommendations, Assessment, Development and Evaluation approach. Meta-analyses were performed where appropriate. Important clinical questions were addressed based on the evidence developed from the systematic literature review. Graded recommendations and ungraded statements were drafted, voted on, and revised until consensus was reached. RESULTS: The systematic literature review identified 75 additional studies that informed the response to the 12 key questions that were developed. Additional clinical questions were addressed resulting in seven graded recommendations and nine ungraded consensus statements. CONCLUSIONS: Evidence suggests that low-dose CT screening for lung cancer can result in a favorable balance of benefit and harms. The selection of screen-eligible individuals, the quality of imaging and image interpretation, the management of screen-detected findings, and the effectiveness of smoking cessation interventions can impact this balance.

Screening for Lung Cancer: CHEST Guideline and Expert Panel Report.

BACKGROUND: Low-dose chest CT screening for lung cancer has become a standard of care in the United States, in large part because of the results of the National Lung Screening Trial (NLST). Additional evidence supporting the net benefit of low-dose chest CT screening for lung cancer, and increased experience in minimizing the potential harms, has accumulated since the prior iteration of these guidelines. Here, we update the evidence base for the benefit, harms, and implementation of low-dose chest CT screening. We use the updated evidence base to provide recommendations where the evidence allows, and statements based on experience and expert consensus where it does not. METHODS: Approved panelists reviewed previously developed key questions using the Population, Intervention, Comparator, Outcome format to address the benefit and harms of low-dose CT screening, and key areas of program implementation. A systematic literature review was conducted using MEDLINE via PubMed, Embase, and the Cochrane Library on a quarterly basis since the time of the previous guideline publication. Reference lists from relevant retrievals were searched, and additional papers were added. Retrieved references were reviewed for relevance by two panel members. The quality of the evidence was assessed for each critical or important outcome of interest using the Grading of Recommendations, Assessment, Development, and Evaluation approach. Meta-analyses were performed when enough evidence was available. Important clinical questions were addressed based on the evidence developed from the systematic literature review. Graded recommendations and ungraded statements were drafted, voted on, and revised until consensus was reached. RESULTS: The systematic literature review identified 75 additional studies that informed the response to the 12 key questions that were developed. Additional clinical questions were addressed resulting in seven graded recommendations and nine ungraded consensus statements. CONCLUSIONS: Evidence suggests that low-dose CT screening for lung cancer can result in a favorable balance of benefit and harms. The selection of screen-eligible individuals, the quality of imaging and image interpretation, the management of screen-detected findings, and the effectiveness of smoking cessation interventions can impact this balance.

Radiation Reduction Strategies in Pediatric Orthopaedics.

INTRODUCTION: Pediatric orthopaedic patients have the potential for significant radiation exposure from the use of imaging studies, such as computed tomography and bone scintigraphy. With the potential for long-term treatment, such as is required for scoliosis or osteogenesis imperfecta, patients are at even greater risk of radiation-induced carcinogenesis. DISCUSSION: Although an association between radiation and cancer risk is evident, causation is difficult to prove because comorbidities or genetic predispositions may play a role in the higher baseline rates of malignancy later in life. Efforts have been made over the years to reduce exposure using more modern imaging techniques and simple radiation reduction strategies. Educational efforts and clinical practice guidelines are decreasing the rate of computed tomography scan use in pediatrics. Although considerable work is being done on the development of radiation-free imaging modalities, imaging that uses ionizing radiation will, in the near term, be necessary in specific circumstances to provide optimal care to pediatric orthopaedic patients. CONCLUSION: Knowledge of the ionizing radiation exposure associated with commonly used tests as well as radiation-reduction strategies is essential for the optimal and safe care of pediatric orthopaedic patients.

First-line therapy: insights from a real-world analysis of cryoablation in patients with atrial fibrillation.

AIMS: Pulmonary vein isolation (PVI) using cryoballoon ablation (CBA) is mainly reserved for patients with drug-refractory or drug-intolerant symptomatic atrial fibrillation. We evaluated a large cohort of patients treated in a real-world setting and examined the safety and efficacy profile of CBA when applied as a first-line treatment for atrial fibrillation. METHODS: In total, 249 patients (23% women; 56 ±â€Š13 years; mean left atrial diameter 41 ±â€Š7 mm; 73.5% paroxysmal atrial fibrillation; and 26.5% persistent atrial fibrillation) underwent an index PVI by CBA. Data were collected prospectively in the framework of the 1STOP ClinicalService project, involving 26 Italian cardiology centers. RESULTS: Median procedure and fluoroscopy times were 90.0 and 21.0 min, respectively. Acute procedural success was 99.8%. Acute/periprocedural complications were observed in seven patients (2.8%), including: four transient diaphragmatic paralyses, one pericardial effusion (not requiring any intervention), one transient ischemic attack, and one minor vascular complication. The Kaplan--Meier freedom from atrial fibrillation recurrence was 86.3% at 12 months and 76% at 24 months. Seventeen patients (6.8%) had a repeat catheter ablation procedure during the follow-up period. At last follow-up, 10% of patients were on an anticoagulation therapy, whereas 6.8% were on an antiarrhythmic drug. CONCLUSION: In our multicenter real-world experience, PVI by CBA in a first-line atrial fibrillation patient population was well tolerated, effective, and promising. CBA with a PVI strategy can be used to treat patients with paroxysmal and persistent atrial fibrillation with good acute procedural success, short procedure times, and acceptable safety. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov (NCT01007474).

Predictive Performance of Blood S100B in the Management of Patients Over 65 Years Old With Mild Traumatic Brain Injury.

BACKGROUND: We previously assessed the inclusion of S100B blood determination into clinical decision rules for mild traumatic brain injury (mTBI) management in the Emergency Department (ED) of Clermont-Ferrand Hospital. At the 0.10 µg/L threshold, S100B reduced the use of cranial computed tomography (CCT) scan in adults by at least 30% with a ~100% sensitivity. Older patients had higher serum S100B values, resulting in lower specificity (18.7%) and decreased CCT reduction. We conducted this study to confirm the age effect on S100B concentrations, and to propose new decisional thresholds for older patients. METHODS: A total of 1172 mTBI patients aged 65 and over were included. They were divided into 3 age groups: 65-79, 80-89, and ≥ 90 years old. S100B's performance to identify intracranial lesions (sensitivity [SE] and specificity [SP]) was assessed using the routine 0.10 µg/L threshold and also other more efficient thresholds established for each age group. RESULTS: S100B concentration medians were 0.18, 0.26, and 0.32 µg/L for the 65-79, 80-89, and ≥ 90 years old age groups, respectively (p < .001). The most efficient thresholds were 0.11 µg/L for the 65-79 age group and 0.15 µg/L for the other groups. At these new thresholds, SP was respectively 28.4%, 34.3%, and 20.5% for each age group versus 24.9%, 18.2%, and 10.5% at the 0.10 µg/L threshold. CONCLUSIONS: Adjustment of the S100B threshold is necessary in older patients' management. An increased threshold of 0.15 µg/L is particularly interesting for patients ≥ 80 years old, allowing a significant increase of CCT scan reduction (29.3%).

The role of computed tomography scan in the diagnosis of COVID-19 pneumonia.

PURPOSE OF REVIEW: To summarize current literature evidence on the role of computed tomography (CT) scan in the diagnosis and assessment of coronavirus disease 2019 (COVID-19) pneumonia. RECENT FINDINGS: Recent guidelines on the use of CT scans in COVID-19 vary between countries. However, the consensus is that it should not be used as the first line; a notion supported by the WHO. Currently, several investigations are being used including reverse transcription PCR testing, chest radiographs, and ultrasound scans, and CT scans. They are ideally performed later during the disease process as the sensitivity and specificity are highest by that time. Typical COVID-19 features on CT scans vary but include vascular enlargement, ground-glass opacities, and ground glass opacification together with consolidation. SUMMARY: Since COVID-19 was declared as a global pandemic, there was a push towards identifying appropriate diagnostic tests that are both reliable and effective. There is a general agreement that CT scans have a high sensitivity but low specificity in diagnosing COVID-19. However, the quality of available studies is not optimal, so this must always be interpreted with the clinical context in mind. Clinicians must aim to weigh up the practicalities and drawbacks of CT scans when considering their use for a patient. The ease and speed of use of CT scans must be balanced with their high radiation doses, and infection control considerations.

Diagnostic Imaging: Appropriate and Safe Use.

The use of diagnostic radiography has doubled in the past two decades. Image Gently (children) and Image Wisely (adults) are multidisciplinary initiatives that seek to reduce radiation exposure by eliminating unnecessary procedures and offering best practices. Patients with an estimated glomerular filtration rate less than 30 mL per minute per 1.73 m2 may have increased risk of nephropathy when exposed to iodinated contrast media and increased risk of nephrogenic systemic fibrosis when exposed to gadolinium-based contrast agents. American College of Radiology Appropriateness Criteria can help guide specific diagnostic imaging choices. Noncontrast head computed tomography is the first-line modality when a stroke is suspected. Magnetic resonance imaging stroke protocols and computed tomography perfusion scans can augment evaluation and potentially expand pharmacologic and endovascular therapy timeframes. Imaging should be avoided in patients with uncomplicated headache syndromes unless the history or physical examination reveals red flag features. Cardiac computed tomography angiography, stress echocardiography, and myocardial perfusion scintigraphy (nuclear stress test) are appropriate for patients with chest pain and low to intermediate cardiovascular risk and have comparable sensitivity and specificity. Computed tomography pulmonary angiography is the preferred test for high-risk patients or those with a positive d-dimer test result, and ventilation-perfusion scintigraphy is reserved for patients with an estimated glomerular filtration rate less than 30 mL per minute per 1.73 m2 or a known contrast allergy. Computed tomography with intravenous contrast is preferred for evaluating adults with suspected appendicitis; however, ultrasonography should precede computed tomography in children, and definitive treatment should be initiated if positive. Ultrasonography is the first-line modality for assessing right upper quadrant pain suggestive of biliary disease. Mass size and patient age dictate surveillance recommendations for adnexal masses. Imaging should not be performed for acute (less than six weeks) low back pain unless red flag features are found on patient history. Ultrasonography should be used for the evaluation of suspicious thyroid nodules identified incidentally on computed tomography.