Machine learning for malignant versus benign focal liver lesions on US and CEUS: a meta-analysis

OBJECTIVES

To perform a meta-analysis of the diagnostic performance of learning (ML) algorithms (conventional and deep learning algorithms) for the classification of malignant versus benign focal liver lesions (FLLs) on US and CEUS.

METHODS

Available databases were searched for relevant published studies through September 2022. Studies met eligibility criteria if they evaluate the diagnostic performance of ML for the classification of malignant and benign focal liver lesions on US and CEUS. The pooled per-lesion sensitivities and specificities for each modality with 95% confidence intervals were calculated.

RESULTS

A total of 8 studies on US, 11 on CEUS, and 1 study evaluating both methods met the inclusion criteria with a total of 34,245 FLLs evaluated. The pooled sensitivity and specificity of ML for the malignancy classification of FLLs were 81.7% (95% CI, 77.2-85.4%) and 84.8% (95% CI, 76.0-90.8%) for US, compared to 87.1% (95% CI, 81.8-91.0%) and 87.0% (95% CI, 83.1-90.1%) for CEUS. In the subgroup analysis of studies that evaluated deep learning algorithms, the sensitivity and specificity of CEUS (n = 4) increased to 92.4% (95% CI, 88.5-95.0%) and 88.2% (95% CI, 81.1-92.9%).

CONCLUSIONS

The diagnostic performance of ML algorithms for the malignant classification of FLLs was high for both US and CEUS with overall similar sensitivity and specificity. The similar performance of US may be related to the higher prevalence of DL models in that group.

Hematocrit and lactate trends help predict outcomes in trauma independent of CT and other clinical parameters

Background

Hematocrit and lactate have an established role in trauma as indicators of bleeding and cell death, respectively. The wide availability of CT imaging and clinical data poses the question of how these can be used in combination to predict outcomes.

Purpose

To assess the utility of hematocrit or lactate trends in predicting intensive care unit (ICU) admission and hospital length of stay (LOS) in patients with torso trauma combined with clinical parameters and injury findings on CT.

Materials and Methods

This was a single-center retrospective study of adults with torso trauma in one year. Trends were defined as a unit change per hour. CT findings and clinical parameters were explanatory variables. Outcomes were ICU admission and hospital LOS. Multivariate logistic and negative binomial regression models were used to calculate the odds ratio (OR) and incident rate ratio (IRR).

Results

Among 840 patients, 561 (72% males, age 39 ± 18) were included, and 168 patients (30%) were admitted to the ICU. Decreasing hematocrit trend [OR 2.54 (1.41-4.58), p = 0.002] and increasing lactate trend [OR 3.85 (1.35-11.01), p = 0.012] were associated with increased odds of ICU admission. LOS median was 2 (IQR: 1-5) days. Decreasing hematocrit trend [IRR 1.37 (1.13-1.66), p = 0.002] and increasing lactate trend [2.02 (1.43-2.85), p < 0.001] were associated with longer hospital LOS.

Conclusion

Hematocrit and lactate trends may be helpful in predicting ICU admission and LOS in torso trauma independent of organ injuries on CT, age, or admission clinical parameters.

Artificial intelligence CAD tools in trauma imaging: a scoping review from the American Society of Emergency Radiology (ASER) AI/ML Expert Panel

BACKGROUND

AI/ML CAD tools can potentially improve outcomes in the high-stakes, high-volume model of trauma radiology. No prior scoping review has been undertaken to comprehensively assess tools in this subspecialty.

PURPOSE

To map the evolution and current state of trauma radiology CAD tools along key dimensions of technology readiness.

METHODS

Following a search of databases, abstract screening, and full-text document review, CAD tool maturity was charted using elements of data curation, performance validation, outcomes research, explainability, user acceptance, and funding patterns. Descriptive statistics were used to illustrate key trends.

RESULTS

A total of 4052 records were screened, and 233 full-text articles were selected for content analysis. Twenty-one papers described FDA-approved commercial tools, and 212 reported algorithm prototypes. Works ranged from foundational research to multi-reader multi-case trials with heterogeneous external data. Scalable convolutional neural network-based implementations increased steeply after 2016 and were used in all commercial products; however, options for explainability were narrow. Of FDA-approved tools, 9/10 performed detection tasks. Dataset sizes ranged from < 100 to > 500,000 patients, and commercialization coincided with public dataset availability. Cross-sectional torso datasets were uniformly small. Data curation methods with ground truth labeling by independent readers were uncommon. No papers assessed user acceptance, and no method included human-computer interaction. The USA and China had the highest research output and frequency of research funding.

CONCLUSIONS

Trauma imaging CAD tools are likely to improve patient care but are currently in an early stage of maturity, with few FDA-approved products for a limited number of uses. The scarcity of high-quality annotated data remains a major barrier.

The Radiology: Artificial Intelligence Trainee Editorial Board: Initial Experience and Future Directions

In 2019, the journal Radiology: Artificial Intelligence introduced its Trainee Editorial Board (TEB) to offer formal training in medical journalism to medical students, radiology residents and fellows, and research-career trainees. The TEB aims to build a community of radiologists, radiation oncologists, medical physicists, and researchers in fields related to artificial intelligence (AI) in radiology. The program presented opportunities to learn about the editorial process, improve skills in writing and reviewing, advance the field of AI in radiology, and help translate and disseminate AI research. To meet these goals, TEB members contribute actively to the editorial process from peer review to publication, participate in educational webinars, and create and curate content in a variety of forms. Almost all of the contact has been mediated through the web. In this article, we share initial experiences and identify future directions and opportunities.

Risk factors for cardiovascular disease among individuals with hepatic steatosis

Cardiovascular disease (CVD) is the leading cause of mortality in adults with hepatic steatosis (HS). However, risk factors for CVD in HS are unknown. We aimed to identify factors associated with coronary artery disease (CAD) and incident major adverse cardiovascular events (MACE) in individuals with HS. We performed a nested cohort study of adults with HS detected on coronary computed tomography in the PROspective Multicenter Imaging Study for Evaluation of chest pain (PROMISE) trial. Obstructive CAD was defined as ≥50% coronary stenosis. MACE included hospitalization for unstable angina, nonfatal myocardial infarction, or all-cause death. Multivariate modeling, adjusted for age, sex, atherosclerotic CVD (ASCVD) risk score and body mass index, identified factors associated with obstructive CAD. Cox regression, adjusted for ASCVD risk score, determined the predictors of MACE. A total of 959 of 3,756 (mean age 59.4 years, 55.0% men) had HS. Obstructive CAD was present in 15.2% (145 of 959). Male sex (adjusted odds ratio [aOR] = 1.83, 95% confidence interval [CI] 1.18-1.2.84; p = 0.007), ASCVD risk score (aOR = 1.05, 95% CI 1.03-1.07; p < 0.001), and n-terminal pro-b-type natriuretic peptide (NT-proBNP; aOR = 1.90, 95% CI 1.38-2.62; p < 0.001) were independently associated with obstructive CAD. In the 25-months median follow-up, MACE occurred in 4.4% (42 of 959). Sedentary lifestyle (adjusted hazard ratio [aHR] = 2.53, 95% CI 1.27-5.03; p = 0.008) and NT-proBNP (aOR = 1.50, 95% CI 1.01-2.25; p = 0.046) independently predicted MACE. Furthermore, the risk of MACE increased by 3% for every 1% increase in ASCVD risk score (aHR = 1.03, 95% CI 1.01-1.05; p = 0.02). Conclusion: In individuals with HS, male sex, NT-pro-BNP, and ASCVD risk score are associated with obstructive CAD. Furthermore, ASCVD, NT-proBNP, and sedentary lifestyle are independent predictors of MACE. These factors, with further validation, may help risk-stratify adults with HS for incident CAD and MACE.

Gamification in Radiology Training Module Developed During the Society for Imaging Informatics in Medicine Annual Meeting Hackathon

The purpose of this manuscript is to report our experience in the 2021 SIIM Virtual Hackathon, where we developed a proof-of-concept of a radiology training module with elements of gamification. In the 50 h allotted in the hackathon, we proposed an idea, connected with colleagues from five different countries, and completed an operational proof-of-concept, which was demonstrated live at the hackathon showcase, competing with eight other teams. Our prototype involved participants annotating publicly available chest radiographs of patients with tuberculosis. We showed how we could give experience points to trainees based on annotation precision compared to ground truth radiologists' annotation, ranked in a live leaderboard. We believe that gamification elements could provide an engaging solution for radiology education. Our project was awarded first place out of eight participating hackathon teams.

Association of Hepatic Steatosis With Major Adverse Cardiovascular Events, Independent of Coronary Artery Disease

BACKGROUND & AIMS

Hepatic steatosis has been associated with increased risk of major adverse cardiovascular events (MACE) but it is not clear whether steatosis is independently associated with risk of MACE. We investigated whether steatosis is associated with risk of MACE independently of the presence and extent of baseline coronary artery disease, assessed by comprehensive contrast-enhanced computed tomography angiography (CTA).

METHODS

We conducted a nested cohort study of 3756 subjects (mean age, 60.6 years; 48.4% men) who underwent coronary CTA at 193 sites in North America, from July 2010 through September 2013, as part of the PROMISE study, which included noninvasive cardiovascular analyses of symptomatic outpatients without coronary artery disease. Independent core laboratory readers measured hepatic and splenic attenuation, using non-contrast computed tomography images to identify steatosis, and evaluated coronary plaques and stenosis in coronary CTA images. We collected data on participants' cardiovascular risk factors, presence of metabolic syndrome, and body mass index. The primary endpoint was an adjudicated composite of MACE (death, myocardial infarction, or unstable angina) during a median follow-up time of 25 months.

RESULTS

Among the 959 subjects who had steatosis (25.5% of the cohort), 42 had MACE (4.4%), whereas among the 2797 subjects without steatosis, 73 had MACE (2.6%) (hazard ratio [HR] for MACE in subjects with steatosis, 1.69; 95% CI, 1.16-2.48; P = .006 for MACE in subjects with vs without steatosis). This association remained after adjustment for atherosclerotic cardiovascular disease risk scores, significant stenosis, and metabolic syndrome (adjusted HR, 1.72; 95% CI, 1.16-2.54; P = .007) or obesity (adjusted HR, 1.75; 95% CI, 1.19-2.59; P = .005). Steatosis remained independently associated with MACE after adjustment for all CTA measures of plaques and stenosis.

CONCLUSIONS

Hepatic steatosis is associated with MACE independently of other cardiovascular risk factors or extent of coronary artery disease. Strategies to reduce steatosis might reduce risk of MACE. ClinicalTrials.gov no: NCT01174550.

How to Use YouTube for Radiology Education

YouTube, the most commonly used free video-sharing platform globally, is increasingly being used as an educational tool in Radiology. Trainees worldwide now have the opportunity to learn about medical imaging at their own pace in the comfort of their homes, without geographical and financial constraints. Unfortunately, because YouTube is an easily accessible platform, it also incurs the risk of disseminating erroneous medical information or low-quality educational content. This article outlines the primary considerations when creating educational content on YouTube, including technical aspects, best practices, and measures to maximize effectiveness and success. Additionally, we discuss the current usage of the platform for Radiology education and its advantages and disadvantages and list some of the most popular Radiology YouTube channels.

Solitary intramuscular myofibroma in an adult: Case report and MR imaging findings

Myofibroma is a benign, soft tissue neoplasm that predominantly affects infants and young children. Most occur in the skin or subcutaneous tissues, with a predilection for the head and neck regions. We describe the magnetic resonance (MR) imaging and histophathologic findings of a rare case of intramuscular myofibroma of the right deltoid in a healthy 30-year-old male. MR imaging revealed a well-circumscribed intramuscular mass, with isointense signal on T1-weighted images, hyperintense signal on T2-weighed images, and a "target-sign" with peripheral rim enhancement after gadolinium administration. The lesion was surgically excised with no complications, and the histopathologic analysis revealed the typical morphologic and histochemical markers of a myofibroma. We conclude that, although rare, myofibroma can be considered in the differential diagnosis of adults with lesions the above signal characteristics.

Early trends and predictors of renal function following computed tomography-guided percutaneous cryoablation of a renal mass in patients with and without prior renal impairment

OBJECTIVE

To assess trends and predictors of the glomerular filtration rate (GFR) after renal mass cryoablation in patients with and without history of renal impairment.

MATERIALS AND METHODS

This was a retrospective study of 39 patients who underwent computed tomography-guided percutaneous cryoablation of a renal mass, divided into two groups: those with prior renal impairment (PRI+); and those without prior renal impairment (PRI-). The GFR trend and the chronic kidney disease stage were evaluated at baseline, as well as at 1, 6, and 12 months after cryoablation. Predictors of GFR at 1 and 6 months were modeled with linear regression.

RESULTS

In both groups, the mean GFR at 1 month and 6 months was significantly lower than at baseline (p < 0.001 and p = 0.01, respectively). Although the GFR was lower across all time points in the PRI+ group (-26.1; p < 0.001), the overall trend was not statistically different from that observed in the PRI- group (p = 0.89). Univariate analysis showed that the decline in GFR at 1 and 6 months correlated with the baseline GFR (0.77 and 0.63; p < 0.001 and p = 0.03, respectively) and with the size of the ablation zone (-7.6 and -12.84, respectively; p = 0.03 for both). However, in the multivariate model, baseline GFR was predictive only of GFR at 1 month (p < 0.001).

CONCLUSION

The trend in GFR decline after cryoablation is similar for patients with and without a history of renal impairment. Baseline GFR predicts the mean GFR in the early post-cryoablation period.

Amyloidosis in the head and neck: CT findings with clinicopathological correlation

PURPOSE

To characterize the CT imaging features of head and neck amyloidosis and correlate with extent of disease and clinical outcomes.

MATERIALS AND METHODS

This retrospective study included 80 patients with head and neck amyloidosis who underwent soft tissue neck CT imaging between November 2003 and April 2018. The CT imaging features including lesion distribution, morphology (focal, diffuse/circumferential, or combined), presence and pattern of calcification, (punctate or diffuse), and thickness of airway lesion were evaluated and compared with the extent of amyloidosis (localized or systemic), and clinical course (stable, no recurrence, or progression requiring repeated surgical treatment).

RESULTS

Localized disease (83.8%, 67/80) was most common with AL type (97.6%, 41/42) representing nearly all cases of head and neck amyloidosis. The larynx was the most frequently affected organ (60.0%, 48/80), specifically the glottis (43.8%, 35/80). Calcification was seen in 65.0% of cases (52/80). Non-airway or tongue lesions were significantly associated with systemic (92.3%, 12/13) as opposed to localized amyloidosis (4.5%, 3/67; P < 0.001). Repeated surgical treatment was significantly associated with laryngeal amyloidosis (35.3%, 12/34; P = 0.002) and multi-centric disease (33.3%, 10/30; P = 0.048). Airway wall thickness in patients who required repeated surgical treatment was significantly greater than in patients with stable or no recurrent disease (P = 0.016).

CONCLUSION

Knowledge of the imaging features of head and neck amyloidosis can aid the diagnosis, disease monitoring, and prediction of patients requiring repeated surgical intervention.

Prognostic Value of Coronary CTA in Stable Chest Pain: CAD-RADS, CAC, and Cardiovascular Events in PROMISE

OBJECTIVES

The purpose of this study was to compare Coronary Artery Disease Reporting and Data System (CAD-RADS) to traditional stenosis categories and the coronary artery calcium score (CACS) for predicting cardiovascular events in patients with stable chest pain and suspected coronary artery disease (CAD).

BACKGROUND

The 2016 CAD-RADS has been established to standardize the reporting of CAD on coronary CT angiography (CTA).

METHODS

PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) trial participants' CTAs were assessed by a central CT core laboratory for CACS, traditional stenosis-based categories, and modified CAD-RADS grade including high-risk coronary plaque (HRP) features. Traditional stenosis categories and CAD-RADS grade were compared for the prediction of the composite endpoint of death, myocardial infarction, or hospitalization for unstable angina over a median follow-up of 25 months. Incremental prognostic value over traditional risk factors and CACS was assessed.

RESULTS

In 3,840 eligible patients (mean age: 60.4 ± 8.2 years; 49% men), 3.0% (115) experienced events. CAD-RADS (concordance statistic [C-statistic] 0.747) had significantly higher discriminatory value than traditional stenosis-based assessments (C-statistic 0.698 to 0.717; all p for comparison ≤0.001). With no plaque (CAD-RADS 0) as the baseline, the hazard ratio (HR) for an event increased from 2.43 (95% confidence interval [CI]: 1.16 to 5.08) for CAD-RADS 1 to 21.84 (95% CI: 8.63 to 55.26) for CAD-RADS 4b and 5. In stepwise nested models, CAD-RADS added incremental prognostic value beyond ASCVD risk score and CACS (C-statistic 0.776 vs. 0.682; p < 0.001), and added incremental value persisted in all CACS strata.

CONCLUSIONS

These data from a large representative contemporary cohort of patients undergoing coronary CTA for stable chest pain support the prognostic value of CAD-RADS as a standard reporting system for coronary CTA.

Using CT texture analysis to differentiate cystic and cystic-appearing odontogenic lesions

PURPOSE

Cystic and cystic-appearing odontogenic lesions of the jaw may appear similar on CT imaging. Accurate diagnosis is often difficult although the relationship of the lesion to the tooth root or crown may offer a clue to the etiology. The purpose of this study was to evaluate CT texture analysis as an aid in differentiating cystic and cystic-appearing odontogenic lesions of the jaw.

METHODS

This was an IRB-approved retrospective study including 42 pathology-proven dentigerous cysts, 37 odontogenic keratocysts, and 19 ameloblastomas. Each lesion was manually segmented on axial CT images, and textural features were analyzed using an in-house-developed Matlab-based texture analysis program that extracted 47 texture features from each segmented volume. Statistical analysis was performed comparing all pairs of the three types of lesions.

RESULTS

Pairwise analysis revealed that nine histogram features, one GLCM feature, three GLRL features, two Laws features, four GLGM features and two Chi-square features showed significant differences between dentigerous cysts and odontogenic keratocysts. Four histogram features and one Chi-square feature showed significant differences between odontogenic keratocysts and ameloblastomas. Two histogram features showed significant differences between dentigerous cysts and ameloblastomas.

CONCLUSIONS

CT texture analysis may be useful as a noninvasive method to obtain additional quantitative information to differentiate cystic and cystic-appearing odontogenic lesions of the jaw.

CT Texture Analysis and Machine Learning Improve Post-ablation Prognostication in Patients with Adrenal Metastases: A Proof of Concept

INTRODUCTION

To assess the performance of pre-ablation computed tomography texture features of adrenal metastases to predict post-treatment local progression and survival in patients who underwent ablation using machine learning as a prediction tool.

MATERIALS AND METHODS

This is a pilot retrospective study of patients with adrenal metastases undergoing ablation. Clinical variables were collected. Thirty-two texture features were extracted from manually segmented adrenal tumors. A univariate cox proportional hazard model was used for prediction of local progression and survival. A linear support vector machine (SVM) learning technique was applied to the texture features and clinical variables, with leave-one-out cross-validation. Receiver operating characteristic analysis and the area under the curve (AUC) were used to assess performance between using clinical variables only versus clinical variables and texture features.

RESULTS

Twenty-one patients (61% male, age 64.1 ± 10.3 years) were included. Mean time to local progression was 29.8 months. Five texture features exhibited association with progression (p < 0.05). The SVM model based on clinical variables alone resulted in an AUC of 0.52, whereas the SVM model that included texture features resulted in an AUC 0.93 (p = 0.01). Mean overall survival was 35 months. Fourteen texture features were associated with survival in the univariate model (p < 0.05). While the trained SVM model based on clinical variables resulted in an AUC of 0.68, the SVM model that included texture features resulted in an AUC of 0.93 (p = 0.024).

DISCUSSION

Pre-ablation texture analysis and machine learning improve local tumor progression and survival prediction in patients with adrenal metastases who undergo ablation.

Acute promyelocytic leukaemia presenting as necrotising fasciitis of the perineum (Fournier gangrene)

We present a case of an unusual presentation of acute promyelocytic leukaemia (APML), which presented with Fournier gangrene (FG). A 38-year-old man presented with malaise, groin swelling, anal bleeding, fever and was found to have FG. Initial workup revealed pancytopaenia, borderline low fibrinogen, prolonged international normalized ratio (INR), which raised the suspicion for leukaemia. The peripheral blood differential revealed leucopaenia with absolute neutropaenia and a 5% abnormal promyelocytes but no blasts, suspicious for APML. Bone marrow biopsy was performed and fluorescence in situ hydridization (FISH), karyotype and PCR confirmed a t(15;17) translocation, establishing a diagnosis of APML. After 1 month of therapy for intermediate risk APML with All-trans retinoic acid (ATRA) and arsenic trioxide (ATO), repeat chromosomal analysis and repeat bone marrow biopsy revealed no evidence of residual APML. After the consolidation phase was started with ATRA and ATO regimen, the wound healed after 2 months and the patient achieved complete remission.

The effect of emphysema on readmission and survival among smokers with heart failure

Heart Failure (HF) and chronic obstructive pulmonary disease (COPD) are morbid diseases that often coexist. In patients with coexisting disease, COPD is an independent risk factor for readmission and mortality. However, spirometry is often inaccurate in those with active heart failure. Therefore, we investigated the association between the presence of emphysema on computed tomography (CT) and readmission rates in smokers admitted with heart failure (HF). The cohort included a consecutive group of smokers discharged with HF from a tertiary center between January 1, 2014 and April 1, 2014 who also had a CT of the chest for dyspnea. The primary endpoint was any readmission for HF before April 1, 2016; secondary endpoints were 30-day readmission for HF, length of stay and all-cause mortality. Over the study period, there were 225 inpatient smokers with HF who had a concurrent chest CT (155 [69%] males, age 69±11 years, ejection fraction [EF] 46±18%, 107 [48%] LVEF of < 50%). Emphysema on CT was present in 103 (46%) and these were older, had a lower BMI, more pack-years, less diabetes and an increased afterload. During a follow-up of 2.1 years, there were 110 (49%) HF readmissions and 55 (24%) deaths. When separated by emphysema on CT, any readmission, 30-day readmission, length of stay and mortality were higher among HF patients with emphysema. In multivariable regression, emphysema by CT was associated with a two-fold higher (adjusted HR 2.11, 95% CI 1.41–3.15, p < 0.001) risk of readmission and a trend toward increased mortality (adjusted HR 1.70 95% CI 0.86–3.34, p = 0.12). In conclusion, emphysema by CT is a frequent finding in smokers hospitalized with HF and is associated with adverse outcomes in HF. This under recognized group of patients with both emphysema and heart failure may benefit from improved recognition and characterization of their co-morbid disease processes and optimization of therapies for their lung disease.

Perivascular Epicardial Fat Stranding at Coronary CT Angiography: A Marker of Acute Plaque Rupture and Spontaneous Coronary Artery Dissection

Purpose To evaluate the frequency and implications of perivascular fat stranding on coronary computed tomography (CT) angiograms obtained for suspected acute coronary syndrome (ACS). Materials and Methods This retrospective registry study was approved by the institutional review board. The authors reviewed the medical records and images of 1403 consecutive patients (796 men, 607 women; mean age, 52.8 years) who underwent coronary CT angiography at the emergency department from February 2012 to March 2016. Fat attenuation, length and number of circumferential quadrants of the affected segment, and attenuation values in the unaffected epicardial and subcutaneous fat were measured. "Cases" were defined as patients with perivascular fat stranding. Patients with significant stenosis but without fat stranding were considered control subjects. Baseline imaging characteristics, ACS frequency, and results of subsequent downstream testing were compared between cases and control subjects by using two-sample t, Mann-Whitney U, and Fisher tests. Results Perivascular fat stranding was seen in 11 subjects, nine with atherosclerotic lesions and two with spontaneous coronary artery dissections, with a mean fat stranding length of 19.2 mm and circumferential extent averaging 2.9 quadrants. The mean attenuation of perivascular fat stranding, normal epicardial fat, and normal subcutaneous fat was 17, -93.2, and -109.3 HU, respectively (P < .001). Significant differences (P < .05) between cases and control subjects included lower Agatston score, presence of wall motion abnormality, and initial elevation of serum troponin level. ACS frequency was 45.4% in cases and 3.8% in control subjects (P = .001). Conclusion Recognition of perivascular fat stranding may be a helpful additional predictor of culprit lesion and marker of risk for ACS in patients with significant stenosis or spontaneous coronary artery dissection. ^© RSNA, 2018 Online supplemental material is available for this article.

Incidental Statin Use and the Risk of Stroke or Transient Ischemic Attack after Radiotherapy for Head and Neck Cancer

Background and Purpose

Interventions to reduce the risk for cerebrovascular events (CVE; stroke and transient ischemic attack [TIA]) after radiotherapy (RT) for head and neck cancer (HNCA) are needed. Among broad populations, statins reduce CVEs; however, whether statins reduce CVEs after RT for HNCA is unclear. Therefore, we aimed to test whether incidental statin use at the time of RT is associated with a lower rate of CVEs after RT for HNCA.

Methods

From an institutional database we identified all consecutive subjects treated with neck RT from 2002 to 2012 for HNCA. Data collection and event adjudication was performed by blinded teams. The primary outcome was a composite of ischemic stroke and TIA. The secondary outcome was ischemic stroke. The association between statin use and events was determined using Cox proportional hazard models after adjustment for traditional and RT-specific risk factors.

Results

The final cohort consisted of 1,011 patients (59±13 years, 30% female, 44% hypertension) with 288 (28%) on statins. Over a median follow-up of 3.4 years (interquartile range, 0.1 to 14) there were 102 CVEs (89 ischemic strokes and 13 TIAs) with 17 in statin users versus 85 in nonstatins users. In a multivariable model containing known predictors of CVE, statins were associated with a reduction in the combination of stroke and TIA (hazard ratio [HR], 0.4; 95% confidence interval [CI], 0.2 to 0.8; P=0.01) and ischemic stroke alone (HR, 0.4; 95% CI, 0.2 to 0.8; P=0.01).

Conclusions

Incidental statin use at the time of RT for HNCA is associated with a lower risk of stroke or TIA.

Identification of coronary artery calcification can optimize risk stratification in patients with acute chest pain

BACKGROUND

The number of patients presenting to the emergency department (ED) with suspected acute coronary syndrome (ACS) is substantial. We tested whether identification of coronary artery calcium (CAC) can improve the negative predictive value (NPV) of clinical risk assessment for ACS in patients with acute chest pain.

METHODS AND RESULTS

We included 826 consecutive patients (mean age: 53±11years; 42% female) without known coronary artery disease (CAD) or initially elevated serum biomarkers, whom underwent non-contrast CT, to assess the CAC score, and CT angiography (CTA), to detect coronary stenosis. We analyzed the diagnostic performance of CAC and the Thrombolysis In Myocardial Infarction (TIMI) risk score for our primary outcomes (ACS and obstructive CAD). No CAC was found in 54% (n=444) of all patients, 63% (n=524) had a TIMI score of 0 and 40% (n=328) had both. The prevalence of obstructive CAD was 16% for ≥50% stenosis and 8.7% for ≥70% stenosis. The incidence of ACS was 7.9%, (MI=11, UAP=54). The NPV of CAC=0 was 99.5% for ACS. The NPV of a combination of TIMI score=0 and no CAC was 89% for any CAD (any plaque or stenosis) and 99.7% for ≥50% stenosis. A 100% NPV was found for ≥70% stenosis and ACS, correctly identifying 328 (40%) patients.

CONCLUSIONS

The exclusion of CAC, in combination with clinical risk assessment, has high clinical value in patients with acute chest pain, as it identifies patients at low risk for ACS and obstructive CAD more accurately as compared to clinical risk assessment alone.

Presence, Characteristics, and Prognostic Associations of Carotid Plaque Among People Living With HIV

BACKGROUND

Data from broad populations have established associations between incidental carotid plaque and vascular events. Among people living with HIV (PLWHIV), the risk of vascular events is increased; however, whether incidental carotid plaque is increased and there is an association between incidental carotid plaque, plaque characteristics, and vascular events among PLWHIV is unclear.

METHODS AND RESULTS

Data from the multi-institutional Research Patient Data Registry were used. Presence and characteristics (high-risk plaque, including spotty calcification and low attenuation) of carotid plaque by computerized tomography among PLWHIV without known vascular disease were described. Data were compared with uninfected controls similar in age, sex, and cardiovascular risk factors, including diabetes mellitus, hyperlipidemia, and cigarette smoking to cases. Primary outcome was an atherosclerotic cardiovascular disease event, and secondary outcome was ischemic stroke. Cohort consisted of 209 PLWHIV (45±10 years, 72% male) and 168 controls. Using computerized tomography, PLWHIV without vascular disease had higher rates of any carotid plaque (34% versus 25%; P=0.04), noncalcified (18% versus 5%; P<0.001) and high-risk plaque (25% versus 16%; P=0.03). Over a follow-up of 3 years, 19 atherosclerotic cardiovascular disease events (9 strokes) occurred. Carotid plaque was independently associated with a 3-fold increase in atherosclerotic cardiovascular disease events among PLWHIV (hazard ratio, 2.91; confidence interval, 1.10-7.7, P=0.03) and a 4-fold increased risk of stroke (hazard ratio, 4.43; confidence interval, 1.17-16.70; P=0.02); high-risk plaque was associated with a 3-fold increased risk of atherosclerotic cardiovascular disease events and a 4-fold increased risk of stroke.

CONCLUSIONS

There is an increase in incidental carotid plaque, noncalcified plaque, and high-risk plaque among PLWHIV, and the presence and characteristics of carotid plaque are associated with subsequent vascular events.

Human Papillomavirus Status and the Risk of Cerebrovascular Events Following Radiation Therapy for Head and Neck Cancer

Background

Radiation therapy (RT) is a standard treatment for head and neck cancer; however, it is associated with inflammation, accelerated atherosclerosis, and cerebrovascular events (CVEs; stroke or transient ischemic attack). Human papillomavirus (HPV) is found in nearly half of head and neck cancers and is associated with inflammation and atherosclerosis. Whether HPV confers an increased risk of CVEs after RT is unknown.

Methods and Results

Using an institutional database, we identified all consecutive patients treated with RT from 2002 to 2012 for head and neck cancer who were tested for HPV. The outcome of interest was the composite of ischemic stroke and transient ischemic attack, and the association between HPV and CVEs was assessed using Cox proportional hazard models, competing risk analysis, and inverse probability weighting. Overall, 326 participants who underwent RT for head and neck cancer were tested for HPV (age 59±12 years, 75% were male, 9% had diabetes mellitus, 45% had hypertension, and 61% were smokers), of which 191 (59%) were tumor HPV positive. Traditional risk factors for CVEs were similar between HPV‐positive and ‐negative patients. Over a median follow‐up of 3.4 years, there were 18 ischemic strokes and 5 transient ischemic attacks (event rate of 1.8% per year). The annual event rate was higher in the HPV‐positive patients compared with the HPV‐negative patients (2.6% versus 0.9%, P=0.002). In a multivariable model, HPV‐positive status was associated with a >4 times increased risk of CVEs (hazard ratio: 4.4; 95% confidence interval, 1.5–13.2; P=0.008).

Conclusions

In this study, HPV‐positive status is associated with an increased risk of stroke or transient ischemic attack following RT for head and neck cancer.

Clinical implementation of an emergency department coronary computed tomographic angiography protocol for triage of patients with suspected acute coronary syndrome

OBJECTIVES

To evaluate the efficiency and safety of emergency department (ED) coronary computed tomography angiography (CTA) during a 3-year clinical experience.

METHODS

Single-center registry of coronary CTA in consecutive ED patients with suspicion of acute coronary syndrome (ACS). The primary outcome was efficiency of coronary CTA defined as the length of hospitalization. Secondary endpoints of safety were defined as the rate of downstream testing, normalcy rates of invasive coronary angiography (ICA), absence of missed ACS, and major adverse cardiac events (MACE) during follow-up, and index radiation exposure.

RESULTS

One thousand twenty two consecutive patients were referred for clinical coronary CTA with suspicion of ACS. Overall, median time to discharge home was 10.5 (5.7-24.1) hours. Patient disposition was 42.7 % direct discharge from the ED, 43.2 % discharge from emergency unit, and 14.1 % hospital admission. ACS rate during index hospitalization was 9.1 %. One hundred ninety two patients underwent additional diagnostic imaging and 77 underwent ICA. The positive predictive value of CTA compared to ICA was 78.9 % (95 %-CI 68.1-87.5 %). Median CT radiation exposure was 4.0 (2.5-5.8) mSv. No ACS was missed; MACE at follow-up after negative CTA was 0.2 %.

CONCLUSIONS

Coronary CTA in an experienced tertiary care setting allows for efficient and safe management of patients with suspicion for ACS.

KEY POINTS

• ED Coronary CTA using advanced systems is associated with low radiation exposure. • Negative coronary CTA is associated with low rates of MACE. • CTA in ED patients enables short median time to discharge home. • CTA strategy is characterized by few downstream tests including unnecessary ICA.

Characterization of the Changes in Cardiac Structure and Function in Mice Treated With Anthracyclines Using Serial Cardiac Magnetic Resonance Imaging

BACKGROUND

Anthracyclines are cardiotoxic; however, there are limited data characterizing the serial changes in cardiac structure and function after anthracyclines. The aim of this study was to use cardiac magnetic resonance to characterize anthracycline-induced cardiotoxicity in mice.

METHODS AND RESULTS

This was a longitudinal cardiac magnetic resonance and histological study of 45 wild-type male mice randomized to doxorubicin (n=30, 5 mg/kg of doxorubicin/week for 5 weeks) or placebo (n=15). A cardiac magnetic resonance was performed at baseline and at 5, 10, and 20 weeks after randomization. Measures of primary interest included left ventricular ejection fraction, myocardial edema (multiecho short-axis spin-echo acquisition), and myocardial fibrosis (Look-Locker gradient echo). In doxorubicin-treated mice versus placebo, there was an increase in myocardial edema at 5 weeks (T2 values of 32±4 versus 21±3 ms; P<0.05), followed by a reduction in left ventricular ejection fraction (54±6 versus 63±5%; P<0.05) and an increase in myocardial fibrosis (extracellular volume of 0.34±0.03 versus 0.27±0.03; P<0.05) at 10 weeks. There was a strong association between the early (5 weeks) increase in edema and the subacute (10 weeks) increase in fibrosis (r=0.90; P<0.001). Both the increase in edema and fibrosis predicted the late doxorubicin-induced mortality in mice (P<0.001).

CONCLUSIONS

Our data suggest that, in mice, anthracycline-induced cardiotoxicity is associated with an early increase in cardiac edema and a subsequent increase in myocardial fibrosis. The early increase in edema and subacute increase in fibrosis are strongly linked and are both predictive of late mortality.

Coronary CT angiography in the emergency department utilizing second and third generation dual source CT

BACKGROUND

Coronary computed tomography angiography (coronary CTA) allows efficient triage of low to intermediate risk patients with suspected acute coronary syndrome (ACS) in the emergency department (ED). Techniques for coronary CTA acquisition in the ED continue to evolve with the establishment of standardized scan protocols and the introduction of newer generations of CT hardware.

OBJECTIVES

To evaluate qualitative and quantitative image quality and radiation dose exposure of coronary CTA acquired on 2nd versus 3rd generation dual source CT (DSCT) scanners using a standardized institutional scan protocol designed for the ED.

METHODS

A retrospective observational case-control study was performed of 246 ED patients referred to coronary CTA with suspicion of ACS (56.5% male; mean age 53.3 ± 11.6 years) between October 2013 and August 2015.123 consecutive patients were scanned on 3rd generation DSCT, and a cohort of 123 patients matched by age, BMI and heart rate were identified who had undergone 2nd generation DSCT imaging utilizing the same standard clinical protocol. Qualitative and quantitative image quality parameters and radiation exposures were evaluated.

RESULTS

Qualitative image quality was significantly higher using 3rd generation DSCT as compared to 2nd generation (p < 0.001). Mean attenuation in the proximal coronary arteries was also significantly higher on 3rd generation DSCT than for 2nd generation (586 HU vs. 426 HU in the left main coronary artery (LM), p < 0.001). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) values, however, were lower in 3rd generation DSCT than 2nd generation (SNR 11.2 [9.9-13.4] vs 13.5 [11.0-15.5] and CNR 12.4 [10.9-14.8] vs 15.2 [12.8-17.9] in the LM, p < 0.001). Median effective dose was also lower for 3rd generation DSCT than for 2nd generation (2.9 [2.3-5.0] mSv and 3.7 mSv [2.5-5.7], respectively) although this trend did not reach statistical significance (p = 0.065).

CONCLUSION

Qualitative image quality and mean CT attenuation values of the assessed coronary segments were significantly higher using 3rd generation DSCT. SNR and CNR were lower on 3rd generation DSCT, however this was accompanied by a trend toward lower radiation dose exposure when using the same standard institutional protocol.