Abdominopelvic CT increases diagnostic certainty and guides management decisions: a prospective investigation of 584 patients in a large academic medical center. AJR Am J Roentgenol. 2011;196:238-243. [PMID: 21257870 DOI: 10.2214/AJR.10.4467]

Investigating the causes and pattern of peritoneal involvement in CT scan and comparison with ultrasound findings in peritoneal conditions: A two-center, cross-sectional study

Background and Aims

Ultrasound and computed tomography (CT) scans can be used as methods to help make a more accurate diagnosis in diseases involving the omentum and peritoneum. The present study was conducted to determine etiology and CT scan pattern of peritoneal involvement and compare it with ultrasound findings.

Methods

Patients referred to Ghaem and Imam Reza hospitals who had undergone CT scans and had involvement of peritoneum in abdominal CT scans were included in the study. The findings identified in the CT scan were recorded. According to the underlying cause determined by laparotomy or laparoscopy sample, each disease's most common pattern of involvement and types of patterns were examined. An ultrasound was conducted for every patient and the obtained information was analyzed.

Results

A total of 101 patients were included in the study, of which 61 patients (59.8%) were female and the rest were male. The most common involvement patterns in CT scans included nodular (37.6%), mixed (21.8%), and omental cake (17.8%), respectively. In 80 patients (79.2%), CT scan findings were consistent with ultrasound, but in 21 patients (20.8%), CT scan findings were not visible in ultrasound. The most common diagnoses of the patients were colorectal adenocarcinoma and gastric adenocarcinoma (20 cases, 19.8% each), followed by ovarian and uterine adenocarcinoma (19 cases, 18.8%).

Conclusion

The most common patterns of involvement of peritoneum in CT scans include nodular pattern, mix, and omental cake. The most common diseases that lead to the involvement of peritoneum are gastrointestinal cancers, uterine and ovarian cancers, and peritonitis.

The utility of the abdominal series in the emergency setting: a retrospective review

PURPOSE

The abdominal series (AXR) remains a frequently ordered test in the emergency department (ED), despite existing literature questioning its utility. The aim of this study was to characterize the use of the AXR in the ED by quantifying how often it is ordered and the frequency of subsequent imaging. Additionally, a time estimate in ED associated with the AXR was quantified. We hypothesized that there would be a low clinical utility of the AXR, and long associated time period spent in the ED.

METHODS

A retrospective audit of AXRs performed in the ED from January to December 2019 was performed. The local picture archiving and communication system (PACS) and electronic medical record were used to collect the variables.

RESULTS

Of 701 AXRs, 438 (62.4%) were reported normal, and 263 (37.6%) were abnormal. A Chi Squared test showed that the two variables (abdominal series result and follow up imaging completion) were significantly related, with p < 0.001. However, the effect size was small (Nagelkerke R square = 0.022). The average time spent in the ED for these patients was 7.27 h, and the average time between the AXR being ordered and interpreted was 1.31 h.

CONCLUSION

The majority of AXRs were reported as normal. Our results showed that AXR had a statistically significant, but low clinically significant predictive ability on subsequent imaging ordering. This supports our hypothesis that the AXR is of low clinical utility with respect to the rate of ordering follow up imaging. The AXR also translated to a quantifiable time interval during the patient's stay in ED. Minimizing overuse of the AXR may result in a decrease in patient duration in the ED.

Ionizing radiation protection and the linear No-threshold controversy: Extent of support or counter to the prevailing paradigm

This study has developed a relationship that categorized radiation protection and allows for a proper, clear, and concise review of the different classifications in terms of principles of protection, dose criteria, categories, fundamental tools, exposure situations, applications and control measures. With the groundwork laid, advances of the linear no-threshold (LNT) model which has attracted attention in the field of radiobiology and epidemiology were examined in detail. Various plausible dose-response relationship scenarios were x-rayed under low-dose extrapolation. Intensive review of factors opposing the LNT model involving radiophobia (including misdiagnosis, alternative surgery/imaging, suppression of ionizing radiation (IR) research); radiobiology (including DNA damage repair, apoptosis/necrosis, senescence protection) and cost issues (including-high operating cost of LNT, incorrect prioritization, exaggeration of LNT impact, risk-to-benefit analysis) were performed. On the other hand, factors supporting the use of LNT were equally examined, they include regulatory bodies' endorsement, insufficient statistical significance, partial DNA repair, variability of irradiated bodies, different latency periods for cancer, dynamic nature of threshold and conflicting interests. After considering the gaps in the scientific investigations that either support or counter the scientific paradigm on the use of LNT model, further research and advocacy is recommended that will ultimately lead to the acceptance of an alternative paradigm by the international regulators.

Abdominal Pain in the Emergency Department: How to Select the Correct Imaging for Diagnosis

Abdominal pain is a common presenting complaint in the emergency department, and utilization of diagnostic imaging is often a key tool in determining its etiology. Plain radiography has limited utility in this population. Computed tomography (CT) is the imaging modality of choice for undifferentiated abdominal pain. Ultrasound and magnetic resonance imaging may be helpful in specific scenarios, primarily in pediatrics and pregnancy, and offer the benefit of eliminating ionizing radiation risk of CT. Guidance for imaging selection is determined by location of pain, special patient considerations, and specific suspected etiologies. Expert guidance is offered by the American College of Radiology Appropriateness Criteria^® which outlines imaging options based on location of pain.

Factors affecting incorrect interpretation of abdominal computed tomography in non-traumatic patients by novice emergency physicians

Objective

Accurate interpretation of computed tomography (CT) scans is critical for patient care in the emergency department. We aimed to identify factors associated with an incorrect interpretation of abdominal CT by novice emergency residents and to analyze the characteristics of incorrectly interpreted scans.

Methods

This retrospective analysis of a prospective observational cohort was conducted at three urban emergency departments. Discrepancies between the interpretations by postgraduate year-1 (PGY-1) emergency residents and the final radiologists’ reports were assessed by independent adjudicators. Potential factors associated with incorrect interpretation included patient age, sex, time of interpretation, and organ category. Adjusted odds ratios (aORs) for incorrect interpretation were calculated using multivariable logistic regression analysis.

Results

Among 1,628 eligible cases, 270 (16.6%) were incorrect. The urinary system was the most correctly interpreted organ system (95.8%, 365/381), while the biliary tract was the most incorrectly interpreted (28.4%, 48/169). Normal CT images showed high false-positive rates of incorrect interpretation (28.2%, 96/340). Organ category was found to be a major determinant of incorrect interpretation. Using the urinary system as a reference, the aOR for incorrect interpretation of biliary tract disease was 9.20 (95% confidence interval, 5.0–16.90) and the aOR for incorrectly interpreting normal CT images was 8.47 (95% confidence interval, 4.85–14.78).

Conclusion

Biliary tract disease is a major factor associated with incorrect preliminary interpretations of abdominal CT scans by PGY-1 emergency residents. PGY-1 residents also showed high false-positive interpretation rates for normal CT images. Emergency residents’ training should focus on these two areas to improve abdominal CT interpretation accuracy.

Can obstructive urolithiasis be safely excluded on contrast CT? A retrospective analysis of contrast-enhanced and noncontrast CT

PURPOSE

The aim of this study was to determine if contrast-enhanced CT can safely exclude obstructive urolithiasis in patients with flank plain. We performed a retrospective cohort analysis to compare the negative predictive values of contrast-enhanced and non-contrast CTs for the detection of obstructing urolithiasis.

METHODS

Through report analysis, we identified all non-contrast and contrast-enhanced CT examinations of the abdomen and pelvis performed on adult patients in the emergency department at a single, multi-site academic medical institution in 2017 with an indication of flank pain. The prevalence of obstructive urolithiasis in each group was calculated. We subsequently analyzed 200 consecutive studies from each of these groups (reported negative for obstructive urolithiasis) for negative predictive value calculation. Follow up abdominal imaging within 7 days from original presentation was used as a reference standard for analysis.

RESULTS

In the noncontrast group, 1 study out of 200 was false negative (negative predictive value = 99.5%). In the contrast-enhanced group, there were no false negatives (negative predictive value = 100%). The prevalence of obstructive urolithiasis was 44.0% (351/797) in the noncontrast group and 18.7% (86/459) in the contrast-enhanced group.

CONCLUSION

Our results suggest that contrast-enhanced CT can safely exclude obstructing ureteral calculi in the setting of acute flank pain. This finding is of clinical relevance given the inherent benefit of IV contrast in diagnosing abdominopelvic pathology.

Impact of clinical information on CT diagnosis by radiologist and subsequent clinical management by physician in acute abdominal pain

OBJECTIVE

The impact of clinical information on radiological diagnoses and subsequent clinical management has not been sufficiently investigated. This study aimed to compare diagnostic performance between radiological reports made with and without clinical information and to evaluate differences in the clinical management decisions based on each of these reports.

METHODS

We retrospectively reviewed 410 patients who presented with acute abdominal pain and underwent unenhanced (n = 248) or enhanced CT (n = 162). Clinical information including age, sex, current and past history, physical findings, and laboratory tests were collected. Six radiologists independently interpreted CTs that were randomly assigned with or without clinical information, made radiological diagnoses, and scored the diagnostic confidence level. Four general and emergency physicians simulated clinical management (i.e., followed up in the outpatient clinic, hospitalized for conservative therapy, or referred to other departments for invasive therapy) based on reports made with or without the clinical information. Reference standards for the radiological diagnoses and clinical management were defined by an independent expert panel.

RESULTS

The radiological diagnoses made with clinical information were more accurate than those made without clinical information (93.7% vs. 87.8%, p = 0.008). Median interpretation time for radiological reporting with clinical information was significantly shorter than that without clinical information (median 122.0 vs. 139.0 s, p < 0.001). Clinical simulation better matched the reference standard for clinical management when radiological diagnoses were made with reference to clinical information (97.3% vs. 87.8%, p < 0.001).

CONCLUSION

Access to adequate clinical information enables accurate radiological diagnoses and appropriate subsequent clinical management of patients with acute abdominal pain.

KEY POINTS

• Radiological interpretation improved diagnostic accuracy and confidence level when clinical information was provided. • Providing clinical information did not extend the interpretation time required by radiologists. • Radiological interpretation with clinical information led to correct clinical management by physicians.

Prevalence of Appendicoliths Detected at CT in Adults With Suspected Appendicitis

OBJECTIVE. With heightened interest in nonoperative antibiotic management of uncomplicated appendicitis, appendicoliths become a more relevant issue, and because of higher failure rates their presence may be considered a contraindication. The purpose of this study was to investigate the prevalence of appendicoliths at CT in adults with suspected appendicitis. MATERIALS AND METHODS. Among adults undergoing MDCT for suspected appendicitis, 248 patients (134 women, 114 men; mean age, 35.2 years) consecutively registered over a 3-year period constituted a cohort with surgically proven appendicitis. A cohort of 248 patients (175 women, 73 men; mean age, 37.7 years) without appendicitis consecutively registered over a 1-year period served as control subjects. CT examinations were reviewed for the presence, size, and attenuation of appendicoliths and whether the appendicoliths were obstructing. In the cohort with appendicitis, degree of inflammation (3-point scale) and likelihood for perforation (5-point scale) were scored. RESULTS. The prevalence of appendicoliths at CT was 38.7% (96/248) among patients with appendicitis and 4.4% (11/248) among control subjects (p < .001). Among the 96 patients with appendicitis who had visible appendicoliths, mean width, length, and maximum attenuation of the dominant appendicolith were 6.0 mm, 8.2 mm, and 313 HU, respectively. In 70.8% (68/96) of patients appendicoliths were obstructing, and 32.3% (31/96) of patients had more than one appendicolith. Inflammation (1.75 vs 1.43) and likelihood of perforation (2.07 vs 1.51) (p < .05) scores were higher among patients with appendicitis who had appendicoliths. Extraluminal appendicoliths were seen in five cases of perforated appendicitis. CONCLUSION. Appendicoliths were identified at CT in nearly 40% of adults with proven appendicitis, compared with slightly more than 4% of those without appendicitis, and were associated with increased inflammation and risk of perforation.

The influence of patient race on the use of diagnostic imaging in United States emergency departments: data from the National Hospital Ambulatory Medical Care survey

BACKGROUND

An established body of literature has shown evidence of implicit bias in the health care system on the basis of patient race and ethnicity that contributes to well documented disparities in outcomes. However, little is known about the influence of patient race and ethnicity on the decision to order diagnostic radiology exams in the acute care setting. This study examines the role of patient race and ethnicity on the likelihood of diagnostic imaging exams being ordered during United States emergency department encounters.

METHODS

Publicly available data from the National Hospital Ambulatory Medical Care Survey Emergency Department sample for the years 2006-2016 was compiled. The proportion of patient encounters where diagnostic imaging was ordered was tabulated by race/ethnicity, sub-divided by imaging modality. A multivariable logistic regression model was used to evaluate the influence of patient race/ethnicity on the ordering of diagnostic imaging controlling for other patient and hospital characteristics. Survey weighting variables were used to formulate national-level estimates.

RESULTS

Using the weighted data, an average of 131,558,553 patient encounters were included each year for the 11-year study period. Imaging was used at 46% of all visits although this varied significantly by patient race and ethnicity with white patients receiving medical imaging at 49% of visits and non-white patients at 41% of visits (p < 0.001). This effect persisted in the controlled regression model and across all imaging modalities with the exception of ultrasound. Other factors with a significant influence on imaging use included patient age, gender, insurance status, number of co-morbidities, hospital setting (urban vs non-urban) and hospital region. There was no evidence to suggest that the disparate use of imaging by patient race and ethnicity changed over the 11-year study time period.

CONCLUSION

The likelihood that a diagnostic imaging exam will be ordered during United States emergency department encounters differs significantly by patient race and ethnicity even when controlling for other patient and hospital characteristics. Further work must be done to understand and mitigate what may represent systematic bias and ensure equitable use of health care resources.

Use of CT Scans for Abdominal Pain in the ED: Factors in Choice

Overutilization of healthcare resources is a threat to long-term healthcare sustainability and patient outcomes. CTis a costly but efficient means of assessing abdominal pain; however, 97 per cent of ED physicians acknowledge its overutilization. This study sought to understand factors that influence ED providers’ decision regarding CT use in the evaluation of abdominal pain. After evaluating a patient for acute abdominal pain, ED providers filled in a form in which the primary diagnosis and index of suspicion were recorded. Bivariate and multivariate analyses were used to identify predictors of outcomes. The CT scan utilization rate was 54.82 per cent. Whereas 34.11 per cent of CT scans were normal, 30 per cent yielded an acute abdominal pathology. Tenderness and rebound tenderness were positive predictors of high index of suspicion [odds ratio (OR) 2.09 and 2.54, respectively]. These variables were also predictive of obtaining a CT scan [OR 2.64 and 3.41, respectively]. Compared with whites, the index of suspicion was 26 per cent and 56 per cent less likely to be high when patients were black [OR 0.73] or Hispanic [OR 0.44] respectively. Blacks and Hispanics were less likely to have CT scans performed than whites [OR 0.58 and 0.48, respectively]. Leukocytosis significantly affected the index of suspicion for acute abdominal pathology, obtaining a CTscan and the acuity of CTscan diagnosis on multivariate analysis. Patients aged ≥60 years had 2.03 odds of acute CT finding compared with those aged <60 years. There is a need for committed efforts to optimize CT scan utilization and eliminate socioeconomic disparities in health care.

Death of the ALARA Radiation Protection Principle as Used in the Medical Sector

ALARA is the acronym for "As Low As Reasonably Achievable." It is a radiation protection concept borne from the linear no-threshold (LNT) hypothesis. There are no valid data today supporting the use of LNT in the low-dose range, so dose as a surrogate for risk in radiological imaging is not appropriate, and therefore, the use of the ALARA concept is obsolete. Continued use of an outdated and erroneous principle unnecessarily constrains medical professionals attempting to deliver high-quality care to patients by leading to a reluctance by doctors to order images, a resistance from patients/parents to receive images, subquality images, repeated imaging, increased radiation exposures, the stifling of low-dose radiation research and treatment, and the propagation of radiophobia and continued endorsement of ALARA by regulatory bodies. All these factors result from the fear of radiogenic cancer, many years in the future, that will not occur. It has been established that the dose threshold for leukemia is higher than previously thought. A low-dose radiation exposure from medical imaging will likely upregulate the body's adaptive protection systems leading to the prevention of future cancers. The ALARA principle, as used as a radiation protection principle throughout medicine, is scientifically defunct and should be abandoned.

Retrospective cohort study on clinical predictors for acute abnormalities on CT scan in adult patients with abdominal pain

PURPOSE

Identification of clinical predictors of acute and surgical pathologies on abdominal CT in patients with non-traumatic abdominal pain (NTAP).

METHODS

Retrospective chart review cohort study of adults who had abdominal CT scans for investigation of NTAP in the Emergency Department in a tertiary care center in Lebanon. Multivariate analyses were performed to identify predictors of pathologies on CT scan.

RESULTS

This study included 147 patients who had abdominal CT scans for NTAP. Mean age was 39.8 ± 15.1 years and 58.5 % of patients were females. Less than half (44.9 %) had normal scans. Women had significantly higher rates of normal scans compared to males. Right lower quadrant (RLQ) tenderness was associated with significantly higher odds of having acute abnormalities on CT and of having surgical diagnoses, while epigastric tenderness was negatively associated with these two outcomes. Right and left upper quadrants and diffuse abdominal tenderness, and an abnormal neutrophil count were found to be associated with surgical diagnoses on CT.

CONCLUSIONS

Women are less likely to have acute and surgical pathologies on CT ordered for non traumatic abdominal pain. Epigastric tenderness is negatively associated with abnormal and surgical CT results while RLQ tenderness is associated with an abnormal CT that is likely surgical in nature. These findings should help improve diagnostic accuracy of ordering providers and improve resource utilization.

Positive Oral Contrast Material for Abdominal CT: Current Clinical Indications and Areas of Controversy

OBJECTIVE. The use of positive oral contrast material for abdominal CT is a frequent protocol issue. Confusion abounds regarding its use, and practice patterns often appear arbitrary. Turning to the existing literature for answers is unrewarding, because most studies are underpowered or not designed to address key endpoints. Even worse, many decisions are now being driven by nonradiologists for throughput gains rather than patient-specific considerations. Herein, the current indications for positive oral contrast material are discussed, including areas of controversy. CONCLUSION. As radiologists, we owe it to our patients to drive the appropriate use of positive oral contrast material. At the very least, we should not allow nonradiologists to restrict its use solely on the basis of throughput concerns; rather, we should allow considerations of image quality and diagnostic confidence to enter into the decision process. Based on differences in prior training and practice patterns, some radiologists will prefer to limit the use of positive oral contrast material more than others. However, for those who believe (as I do) that it can genuinely increase diagnostic confidence and can sometimes (rather unpredictably) make a major impact on diagnosis, it behooves us to keep fighting for its use.

Acute non-traumatic abdominal pain by quadrant: relative yield of CT and clinical evaluation for diagnosis in 1000 patients

OBJECTIVE

To determine the relative diagnostic yield of contrast-enhanced CT in adults presenting with symptoms referable to a specific abdominal quadrant.

METHODS

Electronic health records review systematically identified patients meeting the following inclusion criteria: adults (≥ 18 years) undergoing IV contrast-enhanced abdominopelvic CT for acute non-traumatic symptoms referable to a specific abdominal quadrant (RLQ/LLQ/LUQ/RUQ). The CT-based diagnosis and any clinical diagnosis in the absence of CT diagnosis were recorded. The final cohort of 1000 subjects (mean age, 48.1 years; 647F/353M) consisted of consecutive sub-cohorts of 250 patients for each abdominal quadrant. Positive oral contrast was utilized in 91.6% (916/1000) of cases.

RESULTS

A positive CT diagnosis was provided in 47.3% (473/1000) of all patients, and was highest for LLQ (58.8%) and RLQ (58.0%) symptoms, including diverticulitis and appendicitis in 23.6% and 24.8% cases, respectively. CT positivity was lower for the LUQ (34.4%) and RUQ (38.0%) (p < 0.0001), with no single diagnosis representing > 5% of cases. However, all quadrants provided valuable triage of 218 hospital admissions (21.8%), 83.0% were CT positive, whereas 62.7% of 782 discharged patients were CT negative. Only 7.0% of CT-negative patients were admitted. A clinical-only diagnosis was provided in 9.3% of the total cohort (93/1000), representing 17.6% of the CT-negative cohort (93/527).

CONCLUSION

The rate of positive CT diagnosis is considerably higher for the lower abdominal quadrants, predominately due to appendicitis and diverticulitis. However, CT results (positive vs. negative) for all four quadrants strongly correlated with hospital admission versus discharge. Clinical-only diagnosis represented < 10% of all cases.

Effect of intravenous contrast for CT abdomen and pelvis on detection of urgent and non-urgent pathology: can repeat CT within 72 hours be avoided?

PURPOSE

To determine if administering IV contrast for CT abdomen and pelvis improves detection of urgent and clinically important non-urgent pathology in patients with urgent clinical symptoms compared to patients not receiving IV contrast, and in turn to determine whether repeat CT exams on the same patient within 72 h were of low diagnostic benefit if the first CT was performed with IV contrast.

METHODS

We evaluated 400 consecutive patients who had CT abdomen and pelvis (CT AP) examinations repeated within 72 h. For each patient, demographic data, reason for examination, examination time stamps, and examination technique were documented. CT AP radiology reports were reviewed and both urgent and non-urgent pathology was extracted.

RESULTS

Of 400 patients, 63% had their initial CT AP without contrast. Administration of IV contrast for the first CT AP was associated with increased detection of urgent findings compared with non-contrast CT (p = 0.004) and a contrast-enhanced CT AP following an initial non-contrast CT AP examination better characterized both urgent (p = 0.002) and non-urgent findings (p < 0.001). Adherence to ACR appropriateness criteria for IV contrast administration was associated with increased detection of urgent pathology on the first CT (p = 0.02), and the second CT was more likely to be performed with IV contrast if recommended by the radiologist reading the first CT (p = 0.0006).

CONCLUSION

In the absence of contraindications, encouraging urgent care physicians to preferentially order IV contrast-enhanced CT AP examinations in adherence with ACR appropriateness criteria may increase detection of urgent pathology and avoid short-term repeat CT AP.

Impact of emergency physician experience on decision-making in patients with suspected community-acquired pneumonia and undergoing systematic thoracic CT scan

Objectives

To determine whether the impact of a thoracic CT scan on community-acquired pneumonia (CAP) diagnosis and patient management varies according to emergency physician’s experience (≤10 vs >10 years).

Methods

Early thoracic CT Scan for Community-Acquired Pneumonia at the Emergency Department is an interventional study conducted from November 2011 to January 2013 in four French emergency departments, and included suspected patients with CAP. We analysed changes in emergency physician CAP diagnosis classification levels before and after CT scan; and their agreement with an adjudication committee. We performed univariate analysis to determine the factors associated with modifying the diagnosis classification level to be consistent with the radiologist’s CT scan interpretation.

Results

319 suspected patients with CAP and 136 emergency physicians (75% less experienced with ≤10 years, 25% with >10 years of experience) were included. The percentage of patients whose classification was modified to become consistent with CT scan radiologist’s interpretation was higher among less-experienced than experienced emergency physicians (54.2% vs 40.2%; p=0.02). In univariate analysis, less emergency physician experience was the only factor associated with changing a classification to be consistent with the CT scan radiologist’s interpretation (OR 1.77, 95% CI 1.01 to 3.10, p=0.04). After CT scan, the agreement between emergency physicians and adjudication committee was moderate for less-experienced emergency physicians and slight for experienced emergency physicians (k=0.457 and k=0.196, respectively). After CT scan, less-experienced emergency physicians modified patient management significantly more than experienced emergency physicians (36.1% vs 21.7%, p=0.01).

Conclusions

In clinical practice, less-experienced emergency physicians were more likely to accurately modify their CAP diagnosis and patient management based on thoracic CT scan than more experienced emergency physicians.

Trial registration number

NCT01574066

Concomitant leukocytosis and lymphopenia predict significant pathology at CT of acute abdomen: a case-control study

BACKGROUND

Acute abdominal pain accounts for about 10% of emergency department visits and has progressively become the primary indication for CT scanning in most centers. The goal of our study is to identify biological or clinical variables able to predict or rule out significant pathology (conditions requiring urgent medical or surgical treatment) on abdominal CT in patients presenting to an emergency department with acute abdominal pain.

METHODS

This was a retrospective cohort study performed in the emergency department of an academic center with an annual census of 60'000 patients. One hundred and-nine consecutive patients presenting with an acute non-traumatic abdominal pain, not suspected of appendicitis or renal colic, during the first semester of 2013, who underwent an abdominal CT were included. Two medical students, completing their last year of medical school, extracted the data from patients' electronic health record. Ambiguities in the formulations of clinical symptoms and signs in the patients' records were solved by consulting a board certified emergency physician. Nine clinical and biological variables were extracted: shock index, peritonism, abnormal bowel sounds, fever (> 38 °C), intensity and duration of the pain, leukocytosis (white blood cell count >11G/L), relative lymphopenia (< 15% of total leukocytes), and C-reactive Protein (CRP). These variables were compared to the CT results (reference standard) to determine their ability to predict a significant pathology.

RESULTS

Significant pathology was detected on CT in 71 (65%) patients. Only leukocytosis (odds ratio 3.3, p = 0.008) and relative lymphopenia (odds ratio 3.8, p = 0.002) were associated with significant pathology on CT. The joint presence of these two anomalies was strongly associated with significant pathology on CT (odds ratio 8.2, p = 0.033). Leukocytosis with relative lymphopenia had a specificity of 89% (33/37) and sensitivity of 48% (33/69) for the detection of significant pathology on CT.

CONCLUSION

The high specificity of the association between leukocytosis and relative lymphopenia amongst the study population suggests that these parameters would be sufficient to justify an emergency CT. However, none of the parameters could be used to rule out a significant pathology.

Emergency Department Computed Tomography Use for Non-traumatic Abdominal Pain: Minimal Variability

Introduction

Variability in the use of computed tomography (CT) between providers in the emergency department (ED) suggests that CT is ordered on a provider rather than a patient level. We aimed to evaluate the variability of CT ordering practices for non-traumatic abdominal pain (NTAP) across physicians in the ED using patient-visit and physician-level factors.

Methods

We conducted a retrospective study among 6,409 ED visits for NTAP from January 1 to December 31, 2012, at a large, urban, academic, tertiary-care hospital. We used a two-level hierarchical logistic regression model to estimate inter-physician variation. Intraclass correlation coefficient (ICC) was calculated.

Results

The hierarchical logistic regression analyses showed that patient-visit factors including younger age, arrival mode by ambulance, prior CT, >79 ED arrivals in the previous four hours, and ultrasound had statistically significant negative associations with physician CT ordering, while surgical team admission and white blood count (WBC) >12.5 K/millimeter cubed (mm³) had statistically significant positive associations with physician CT ordering. With physician-level factors, only physicians with >21 years experience after medical school graduation showed statistical significance negatively associated with physician CT ordering. Our data demonstrated increased CT ordering from the mean in only one out of 43 providers (2.3%), which indicated limited variation across physicians to order CT. After adjusting for patient-visit and physician-level factors, the calculated ICC was 1.46%.

Conclusion

We found minimal physician variability in CT ordering practices for NTAP. Patient-visit factors such as age, arrival mode, admission team, prior CT, ED arrivals in previous four hours, ultrasound, and WBC count were found to largely influence CT ordering practices.

Clinical impact of computed tomography in the emergency department in nontraumatic chest and abdominal conditions

AIM

To evaluate the clinical impact of CT scan in modifying the clinical management in patients referred to the emergency department.

METHODS

We prospectively evaluated 300 patients (177 males, 63 ± 18 years old) admitted in the emergency department (ED) of a single institution, who underwent a CT examination for thoracic and/or abdominal complains. Demographic and clinical data were collected. Hypothesized outcome prior to CT scan and final management (i.e., discharge, short observation in the ED, hospitalization, and department of admission) were compared.

RESULTS

After CT examination, a major variation in diagnosis occurred in 37% of cases and clinical management changed in 43%, occurring in 51% of patients who underwent abdominal CT, in 40% of chest CT, and in 29% of chest/abdominal CT (P = 0.015). Department of hospitalization changed in 26% of cases (P < 0.001). Clinical impact of CT scan was significantly associated (P = 0.001) with the color code at admission. In particular, the more severe was the clinical condition, the lower was the variation of management after CT examination.

CONCLUSIONS

This work confirms the crucial role of CT examination in the management of nontraumatic patients admitted to the ED, both in terms of better clarifying the diagnosis and in influencing the clinical management.

Magnitude of non-operative surgical emergency admissions; service implications for surgical and radiological practice

BACKGROUND

Financial sustainability is an area of sharp ongoing focus across the broad spectrum of the Irish Health Service. Recent attention has been drawn to the financial implications of non-operative surgical admissions, suggesting that some of these may be unnecessary.

AIMS

In this study, we aim to determine the volume of emergency surgical admissions to Mayo University Hospital (MUH), in particular, to identify the scale of non-operative admissions and to assess the wider inherent implications for acute hospital services.

METHODS

An electronic handover system for emergency surgical admissions was introduced in MUH in September 2014. All surgical admissions from September 1st 2014 to August 31st 2015 were identified from this prospectively maintained database. HIPE (Hospital Inpatient Enquiry) data were not used in this study. Theatre logbooks confirmed those patients who required operative intervention.

RESULTS

1466 patients were admitted as emergencies during the study period. 58 % (850) were male and median age was 48 years (0-100). Average length of stay was 5 days (range 1-125). 327 patients (22.3 %) required operative intervention. The most commonly performed procedure was appendicectomy (52.5 %). 48 (3.3 %) patients were transferred to other hospitals. 131 (8.9 %) admissions related to the acute urological conditions. Of the 1466 admissions, 546 underwent a CT scan, while 342 patients proceeded to ultrasound.

CONCLUSION

Almost 80 % of all surgical emergency admissions were discharged without undergoing a formal operative procedure while generating a significant workload for the radiology department. Changes in working practices and hospital network structures will be required to reduce the burden of non-operative emergency admissions.

Acute Abdomen in the Emergency Department: Is CT a Time-Limiting Factor?

OBJECTIVE

The purpose of this study was to quantify and integrate key emergency department (ED) and radiology department workflow time intervals within the ED length of stay (LOS) for patients presenting with acute abdomen who require CT.

MATERIALS AND METHODS

An 11-month retrospective review was performed of all patients presenting to the ED with an acute abdomen who required abdominal CT. Nine key time points associated with ED LOS and CT workflow were collected: triage, physician assessment, CT request, porter schedule, CT start, CT complete, provision of first CT report, ED disposition decision, and physical discharge. The median and 90th percentile times for each interval were reported.

RESULTS

Ninety-six percent (2194/2292) of ED encounters during the study period met the inclusion criteria. The median ED LOS was 9.22 hours (90th percentile, 15.7 hours). Intervals associated with CT workflow accounted for 29% of the total LOS. Radiology turnaround time accounted for 32% of the entire CT workflow interval. Timeline analysis found three unique patterns of ED disposition: disposition after initial imaging report, disposition before report, and disposition before CT.

CONCLUSION

To our knowledge, this study is the first to quantify the contribution of CT-related workflow time intervals within the context of ED LOS. We have shown that patients do not have identical ED transit pathways, and this may under- or overestimate time interval calculations. These results show the importance of site-specific ED LOS timeline analysis to identify potential targets for quality improvement and serve as baseline targets for measuring future quality improvement initiatives.

Incidental findings detected on emergency abdominal CT scans: a 1-year review

INTRODUCTION

In recent years, there has been a substantial rise in the use of computed tomography (CT) in the emergency medicine setting. Accordingly, with increased CT usage there has been an upsurge in incidental pathology detection.

METHODS

A retrospective review of all emergency CT abdominal scans performed at a university teaching hospital was examined. The frequency of incidental findings, their clinical significance and workload effect for the radiology department was assessed.

RESULTS

1155 patients had an emergency abdominal CT scan of which 700 had incidental findings detected. Of the incidental findings, 143 were deemed indeterminate requiring urgent investigations. Twenty-four occult neoplasms were confirmed subsequently. Additionally, 259 patients were recommended for additional diagnostics. The cumulative effect of the initial emergency abdominal CT was 15,015 relative value units (RVU). Subsequent imaging of incidental findings resulted in another 1674 RVU workload for radiology.

CONCLUSION

Incidental findings cause considerable debate and concern over which patients require significant follow-up, investigations, and/or surveillance. This exerts significant pressures on sub-specialties for their expert input, with increased workload and implications on healthcare service provision.

Comparative Effectiveness Research: Alternatives to "Traditional" Computed Tomography Use in the Acute Care Setting

Computed tomography (CT) scanning is an essential diagnostic tool and has revolutionized care of patients in the acute care setting. However, there is widespread agreement that overutilization of CT, where benefits do not exceed possible costs or harms, is occurring. The goal was to seek consensus in identifying and prioritizing research questions and themes that involve the comparative effectiveness of "traditional" CT use versus alternative diagnostic strategies in the acute care setting. A modified Delphi technique was used that included input from emergency physicians, emergency radiologists, medical physicists, and an industry expert to achieve this.

Concurrent presentation of appendicitis and acute cholecystitis: diagnosis of rare occurrence

A 67-year-old woman presented with a 2-day history of central abdominal pain migrating to the right upper and lower abdomen. On examination she was normothermic but tachycardic. Inflammatory markers were noted to be elevated with a white cell count of 18.5×10(9)/L and C reactive protein of 265 mg/L. A CT scan revealed dual pathology of appendicitis and acute cholecystitis, which was confirmed intraoperatively and histologically.

Facial Fracture in the Setting of Whole-Body CT for Trauma: Incidence and Clinical Predictors

OBJECTIVE

The objective of our study was to identify the incidence and clinical predictors of facial fracture in the setting of whole-body MDCT for trauma.

MATERIALS AND METHODS

The clinical data from the electronic medical records, including the final radiology reports, of 486 consecutive patients who underwent MDCT for trauma (head, cervical spine, chest, abdomen, and pelvis examinations) with dedicated maxillofacial reconstructions from October 1, 2011, to July 31, 2013, were studied. The clinical variables were compared between cohorts of patients with and those without facial fracture. The two-sample t test was used to compare continuous variables, and the Fisher exact test was used to compare categoric variables.

RESULTS

Two hundred sixteen (44.4%) patients had at least one fracture on the dedicated maxillofacial CT examinations, 215 of whom had facial physical examination findings (sensitivity = 99.5%). Of the 28 patients without documented physical examination findings, 27 did not have a facial fracture (negative predictive value = 96.4%). Statistically significant differences were found between positive and negative cases of facial fracture in patients with a Glasgow coma scale (GCS) score of 8 or less (p < 0.0001), an injury severity score of 16 or greater (p < 0.0001), acute alcohol intoxication according to blood alcohol concentration (BAC) (p = 0.0387), intubation at presentation (p < 0.0001), positive physical examination findings (p < 0.0001), and loss of consciousness (p = 0.0364). Falls from a height greater than standing height and open-vehicle collisions had the highest fracture rates (80.0% and 58.3%, respectively).

CONCLUSION

A negative finding at facial physical examination reliably excluded fracture. Clinical variables positively associated with facial fracture included the following: GCS score of 8 or less, ISS of 16 or greater, alcohol intoxication according to BAC, intubation at presentation, loss of consciousness, and the presence of abnormal facial findings at physical examination.

Renal stones on portal venous phase contrast-enhanced CT: does intravenous contrast interfere with detection?

PURPOSE

To determine the sensitivity of portal venous phase contrast-enhanced CT for the detection of renal stones.

METHODS

This retrospective study included 97 CT examinations of the abdomen without and with intravenous contrast, including 85 (87.6%) examinations with at least one renal stone on the "gold standard" noncontrast images, as scored by a single radiologist. Three other radiologists each independently reviewed only the contrast-enhanced images from all 97 examinations and recorded all renal stones. Reviewer sensitivity for stones was categorized by stone diameter. Reviewer sensitivity and specificity for stone disease were also calculated on a per-kidney basis.

RESULTS

The 97 cases included a total of 238 stones ≥1 mm, with a mean (±SD) of 1.2 ± 1.9 stones per kidney and a stone diameter of 3.5 ± 3.0 mm. Pooling data for the three reviewers, sensitivity for all stones was 81%; sensitivity for stones ≥2, ≥3, ≥4, and ≥5 mm was 88%, 95%, 99%, and 98%, respectively. Sensitivity for stone disease on a per-kidney basis was 94% when considering all stones; when considering only stones ≥2, ≥3, and ≥4 mm, sensitivity was 96%, 99%, and 100%, respectively. Specificity for stone disease on a per-kidney basis was 98% overall, 99% when considering only stones ≥2 mm, and 100% when considering only stones ≥3 mm.

CONCLUSION

Contrast-enhanced CT is highly sensitive for the detection of renal stones ≥3 mm in diameter and less sensitive for smaller stones. In cases where the clinical diagnosis is uncertain and performance of a CT examination is being contemplated, intravenous contrast utilization would allow assessment for stone disease while also optimizing evaluation for other conditions.

Do we really need additional contrast-enhanced abdominal computed tomography for differential diagnosis in triage of middle-aged subjects with suspected biliary pain

Enhanced computed tomography (CT) is widely used for evaluating acute biliary pain in the emergency department (ED). However, concern about radiation exposure from CT has also increased. We investigated the usefulness of pre-contrast CT for differential diagnosis in middle-aged subjects with suspected biliary pain.A total of 183 subjects, who visited the ED for suspected biliary pain from January 2011 to December 2012, were included. Retrospectively, pre-contrast phase and multiphase CT findings were reviewed and the detection rate of findings suggesting disease requiring significant treatment by noncontrast CT (NCCT) was compared with cases detected by multiphase CT.Approximately 70% of total subjects had a significant condition, including 1 case of gallbladder cancer and 126 (68.8%) cases requiring intervention (122 biliary stone-related diseases, 3 liver abscesses, and 1 liver hemangioma). The rate of overlooking malignancy without contrast enhancement was calculated to be 0% to 1.5%. Biliary stones and liver space-occupying lesions were found equally on NCCT and multiphase CT. Calculated probable rates of overlooking acute cholecystitis and biliary obstruction were maximally 6.8% and 4.2% respectively. Incidental significant finding unrelated with pain consisted of 1 case of adrenal incidentaloma, which was also observed in NCCT.NCCT might be sufficient to detect life-threatening or significant disease requiring early treatment in young adults with biliary pain.

Diagnostic emergency imaging utilization at an academic trauma center from 1996 to 2012

PURPOSE

The aim of this study was to retrospectively review the growth rate in emergency radiology volume at an urban academic trauma center from 1996 to 2012.

METHODS

The authors reviewed aggregated billing data, for which the requirement for institutional review board approval was waived, from 1,458,230 diagnostic radiologic examinations ordered for emergency department (ED) visits from 1996 to 2012. The growth rate was calculated as the average annual percentage change in imaging examinations per ED visits. The growth rates between 1996 to 2003 and 2004 to 2012 were statistically compared using a t test.

RESULTS

ED patient visits showed continual growth at an average of 3% per year. Total imaging per ED visit grew from 1996 to 2003 at 4 ± 4% per year but significantly decreased from 2004 to 2012 at -2 ± 3% per year (P = .01). By modality, statistically significant decreased growth was observed in CT and MRI from 2004 to 2012. Ultrasound and x-ray showed unchanged growth from 1996 through 2012. ED physician ultrasound data available for 2002 to 2011 also showed increased growth.

CONCLUSIONS

When adjusting ED imaging volume by ED visits, significantly decreased growth of overall ED imaging, specifically CT and MRI, was observed during the past 9 years. This may be due to slowing of new imaging indications, improved awareness of practice guidelines, and increased use of ultrasound. Although the national health care discussion focuses on continual imaging growth, these results demonstrate that long-term stability in ED imaging utilization is achievable.

Appropriateness and imaging utilization: "computerized provider order entry and decision support"

Modern imaging methods have been transformative in improving medical care. Cross-sectional imaging has largely eliminated the need for invasive "exploratory" surgery and is widely used to triage acutely ill patients. However, how to best use medical imaging with ongoing concerns related to overall costs and radiation risks remains controversial. Imaging saves lives, but overuse of imaging can add unnecessary costs to the health system and add to the radiation burden of the population. In this article, the American College of Radiology Appropriateness Criteria (ACRAC) are reviewed, while the Massachusetts General Hospital experience with a computerized physician (provider) order entry system and other approaches to utilization management are discussed. There are strong evidence-based indicators of appropriateness for a substantial percentage of common imaging applications and where this is the case, decision support systems based on ACRAC or other criteria can and should be used. Standardize health care delivery and elimination of wasteful practice variation can be achieved without the art of medicine being ignored or devalued.

Predictive factors for clinically actionable computed tomography findings in inflammatory bowel disease patients seen in the emergency department with acute gastrointestinal symptoms

BACKGROUND

The wide use of abdomino-pelvic computed tomography (APCT) in emergency departments (ED) has raised the concern for radiation exposure, costs and potential reactions to contrast agents. The aim of this study was to determine the yield and predictive factors for clinically actionable findings (CAF) in APCTs performed in patients with inflammatory bowel disease (IBD) who visit the ED.

METHODS

We performed a cross-sectional study including patients with IBD who visited the ED. Variables considered were demographics, IBD phenotype, clinical symptoms, IBD medication use prior to ED visit, laboratory values, and imaging results. The primary outcome was a composite of CAF, defined as new, intra-abdominal abscess or tumor, bowel obstruction, fistulae, diverticulitis, choledocholithiasis, or appendicitis.

RESULTS

354 patients were included. One or more CAF were reported in 26.6% of the APCTs (32.1% in CD and 12.8% in UC [p<0.01]). Independent predictive variables of CAF in CD were: CRP level ≥5mg/dl (p=0.04), previous history of IBD surgery (p=0.037), Black race (p<0.01) and low body mass index (p<0.01). None of the study variables predicted CAF in UC.

CONCLUSIONS

The yield for CAF with APCT in the ED was high for CD patients but minimal for those with UC and was not improved by the use of contrast. Elevated CRP, low BMI, Black race and previous history of IBD surgery predicted CAF in CD but no variables were predictive of CAF in UC.

Journal club: Acute abdominal pain in elderly patients: effect of radiologist awareness of clinicobiologic information on CT accuracy

OBJECTIVE

The purpose of this study was to assess whether the availability of clinicobiologic findings would affect the diagnostic performance of CT of elderly emergency department patients with nontraumatic acute abdominal pain.

MATERIALS AND METHODS

The cases of 333 consecutively registered patients 75 years old or older presenting to the emergency department with acute abdominal pain and who underwent CT were retrospectively reviewed by two radiologists blinded or not to the patient's clinicobiologic results. Diagnostic accuracy was calculated according to the level of correctly classified cases in both the entire cohort and a surgical subgroup and was compared between readings performed with and without knowledge of the clinicobiologic findings. Agreement between each reading and the reference diagnosis and interobserver agreement were assessed with kappa statistics.

RESULTS

In both the entire cohort (87.4% vs 85.3%, p = 0.07) and the surgical group (94% vs 91%, p = 0.15), there was no significant difference in CT accuracy between diagnoses made when the radiologist was aware and those made when the radiologist was not aware of the clinicobiologic findings. Agreement between the CT diagnosis and the final diagnosis was excellent whether or not the radiologist was aware of the clinicobiologic findings.

CONCLUSION

In the care of elderly patients, CT is accurate for diagnosing the cause of acute abdominal pain, particularly when it is of surgical origin, regardless of the availability of clinical and biologic findings. Thus CT interpretation should not be delayed until complete clinicobiologic data are available, and the images should be quickly transmitted to the emergency physician so that appropriate therapy can be begun.

Clinical value of CT in early diagnosis and treatment of acute abdomen

It is critical to select a fast and accurate method for the early diagnosis and treatment of acute abdomen. CT displays important application value in the early diagnosis and treatment of acute abdomen because of its convenient and intuitive features, advantages in terms of sensitivity and specificity compared with other methods, and the relatively low economic cost. In this paper, we summarize the application value of abdominal CT in the early diagnosis and treatment of acute abdomen by analyzing the characteristics of acute abdomen, comparing CT examination with other methods, and presenting several specific cases.

CT of urolithiasis: comparison of image quality and diagnostic confidence using filtered back projection and iterative reconstruction techniques

RATIONALE AND OBJECTIVES

To compare the image quality and diagnostic confidence of low-dose computed tomography (CT) of urololithiasis using filtered back projection (FBP) and iterative reconstruction techniques (IRT).

MATERIALS AND METHODS

A 4.8 × 4.3 × 5.2 mm(3) uric acid ureteral stone was placed inside an anthropomorphic Alderson phantom at the pelvic level. Fifteen scans were performed on a 64-row dual-source CT system using different tube voltages (80, 100, and 120 kV) and current-time products (8, 15, 30, 70, and 100 mAs). Image reconstruction using FBP and IRT (iterative reconstruction in image space) resulted in 30 data sets. Objective image quality was evaluated by noise measurements. Effective doses were estimated for each data set with use of an established dosimetry program. Subjective image quality and confidence level were rated by two radiologists.

RESULTS

Noise was systematically lower for images reconstructed with IRT compared to FBP (55 ± 30 vs 65 ± 26 Hounsfield units; P = .004) for volume CT dose index values above about 0.6 mGy (or an effective dose of about 0.4 mSv for both sexes). For the 14 scans rated to have diagnostic image quality, the estimated effective doses ranged from 0.3 to 2.5 mSv for males and from 0.4 to 3.1 mSv for females. Subjective image quality and diagnostic confidence for IRT was not significantly better than those for FBP.

CONCLUSIONS

In a phantom study for CT of urolithiasis, IRT improves objective image quality compared to FBP above a certain dose threshold. However, this does not translate into improved subjective image quality or a higher degree of confidence for the diagnosis of high-contrast urinary stones.