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Background RSNA COVID-19 chest CT consensus guidelines are widely used, but their true positive rate for COVID-19 pneumonia has not been assessed among vaccinated patients. Purpose To assess true positive rate of RSNA typical chest CT findings of COVID-19 among fully vaccinated subjects with PCR-confirmed COVID-19 infection compared with unvaccinated subjects. Materials and Methods Patients with COVID Typical chest CT findings and one positive or two negative PCR tests for COVID-19 within 7 days of their chest CT between January 2021 - January 2022 at a quaternary academic medical center were included. True positives were defined as chest CTs interpreted as COVID Typical and PCR-confirmed COVID-19 infection within 7 days. Logistic regression models were constructed to quantify the association between PCR results and vaccination status, vaccination status and COVID-19 variants, and vaccination status and months. Results 652 subjects (median age 59, [IQR, 48-72]); 371 [57%] men) with CT scans classified as COVID Typical were included. 483 (74%) were unvaccinated and 169 (26%) were fully vaccinated. The overall true positive rate of COVID Typical CTs was lower among vaccinated versus unvaccinated (70/169 [41%; 95% CI: 34, 49%] vs 352/483 [73%; 69, 77%]; OR (95% CI): 3.8 (2.6, 5.5); P.001). Unvaccinated subjects were more likely to have true positive CTs compared with fully vaccinated subjects during the peaks of COVID-19 variants Alpha (OR, 16 [95% CI: 6.1, 42]

While peripheral nerve stimulation (PNS) has shown promise in applications ranging from peripheral nerve regeneration after injury to therapeutic organ stimulation, clinical implementation has been impeded by various technological limitations, including surgical placement, lead migration, and atraumatic removal. Here, we describe the design and validation of a new platform for nerve regeneration and interfacing: Absorbable, Conductive, Electrotherapeutic Scaffolds (ACES). ACES are comprised of an alginate/poly-acrylamide interpenetrating network hydrogel optimized for both open and minimally invasive percutaneous approaches. In a rodent model of sciatic nerve repair, ACES significantly improved motor and sensory recovery (p < 0.05), increased muscle mass (p < 0.05), and increased axonogenesis (p < 0.05). Triggered dissolution of ACES enabled atraumatic, percutaneous removal of leads at forces significantly lower than controls (p < 0.05). In a porcine model, ultrasound-guided percutaneous placement of leads with an injectable ACES near the femoral and cervical vagus nerves facilitated stimulus conduction at significantly greater lengths than saline controls (p < 0.05). Overall, ACES facilitated lead placement, stabilization, stimulation and atraumatic removal enabling therapeutic PNS as demonstrated in small and large animal models.

To determine the pathologic response of computed tomography-guided percutaneous microwave ablation as bridging therapy for patients with hepatocellular carcinoma awaiting liver transplant, and its subsequent effect on survival. A single-center retrospective analysis was conducted on 62 patients (M:F = 50:12) with mean age of 59.6 years ± 7.2 months (SD). Sixty-four total MWA procedures were performed for hepatocellular carcinomas within Milan criteria as bridging therapy to subsequent orthotopic liver transplant between August 2014 and September 2018. The pathology reports of the explanted livers were reviewed to assess for residual disease. Residual disease was categorized as complete or incomplete necrosis. Patient demographics, tumor/procedural characteristics, and laboratory values were evaluated. Survival from time of ablation and time of transplantation were recorded and compared between cohorts using log rank tests. The mean tumor size was 2.4 cm ± 0.7 cm (SD), (range = 1–4.6 cm). 32 (50%) cases required hydrodissection. Histopathologic necrosis was seen in 66% of cases at time of liver transplantation. Median time to liver transplant post-MWA was 12.6 months. [IQR = 8.6–14.8 months]. The median survival from ablation was 60.8 months [IQR = 45.5–73.7 months], and the median survival from transplant was 49.3 months [IQR = 33.7–60.1 months]. There was no significant difference in survival for patients with complete versus incomplete necrosis from ablation or liver transplant (p = 0.49, p = 0.46, respectively). Computed tomography-guided percutaneous microwave ablation is an effective bridge to orthotopic liver transplantation for patients with hepatocellular carcinoma. Level 3, non-randomized controlled cohort study/follow-up study.

Purpose To analyze the effect of a patient’s renal failure status on acute outcomes after lower extremity endovascular interventions for peripheral artery disease. Materials and Methods A retrospective analysis of the American College of Surgery National Surgical Quality Improvement Program database from 2014 to 2017 was conducted. Patients were included based on current procedural terminology codes. They were divided into renal failure cohorts. Six thousand seven hundred and sixty-five patients were included in the analysis, 11.0% of whom had renal failure. A univariate analysis was performed using chi-squared test or Fischer’s exact test as appropriate. Multivariate logistic regression models were constructed, while controlling for relevant patient factors, to identify the effect of renal failure on several outcomes of interest after the intervention. A sensitivity analysis was performed with a propensity score-matched cohort. Results Patients with renal failure were more likely to have infrapopliteal interventions (38.0% vs 20.9%), critical limb ischemia with tissue loss (73.5% vs 38.9%), diabetes (70.9% vs 52.3%), preoperative wound infection (59.2% vs 30.7%), mortality (5.1% vs 1.3%), prolonged hospital stay (68.5% vs 46.5%), transfusion after the intervention (13.3% vs 9.1%), reoperation (18.3% vs 9.5%), and readmission (24.9% vs 12.6%), compared to patients without renal failure. The multivariate analysis found renal failure to be significant for mortality (odds ratio [OR] = 4.11, 95% confidence interval [CI] = 2.71–6.24), any complication (OR = 2.03, 95% CI = 1.72–2.39), extended length of stay (OR = 1.53, 95% CI = 1.28–1.83), sepsis (OR = 2.37, 95% CI = 1.60–3.51), readmission (OR = 1.89, 95% CI = 1.57–2.29), reoperation (OR = 1.84, 95% CI = 1.48–2.27), major adverse cardiovascular event (OR = 3.50, 95% CI = 2.54–4.84), and major adverse limb event (OR = 1.97, 95% CI = 1.55–2.51). P value was Conclusions Renal failure before the intervention places patients at a significantly elevated risk of morbidity and mortality following endovascular revascularization procedures for peripheral artery disease.

Background Disease severity on chest radiographs has been associated with higher risk of disease progression and adverse outcomes from coronavirus disease 2019 (COVID-19). Few studies have evaluated COVID-19-related racial and/or ethnic disparities in radiology. Purpose To evaluate whether non-White minority patients hospitalized with confirmed COVID-19 infection presented with increased severity on admission chest radiographs compared with White or non-Hispanic patients. Materials and Methods This single-institution retrospective cohort study was approved by the institutional review board. Patients hospitalized with confirmed COVID-19 infection between March 17, 2020, and April 10, 2020, were identified by using the electronic medical record (n = 326; mean age, 59 years ±17 [standard deviation]; male-to-female ratio: 188:138). The primary outcome was the severity of lung disease on admission chest radiographs, measured by using the modified Radiographic Assessment of Lung Edema (mRALE) score. The secondary outcome was a composite adverse clinical outcome of intubation, intensive care unit admission, or death. The primary exposure was the racial and/or ethnic category: White or non-Hispanic versus non-White (ie, Hispanic, Black, Asian, or other). Multivariable linear regression analyses were performed to evaluate the association between mRALE scores and race and/or ethnicity. Results Non-White patients had significantly higher mRALE scores (median score, 6.1; 95% confidence interval [CI]: 5.4, 6.7) compared with White or non-Hispanic patients (median score, 4.2; 95% CI: 3.6, 4.9) (unadjusted average difference, 1.8; 95% CI: 0.9, 2.8; P < .01). For both White (adjusted hazard ratio, 1.3; 95% CI: 1.2, 1.4; P < .001) and non-White (adjusted hazard ratio, 1.2; 95% CI: 1.1, 1.3; P < .001) patients, increasing mRALE scores were associated with a higher likelihood of experiencing composite adverse outcome with no evidence of interaction (P = .16). Multivariable linear regression analyses demonstrated that non-White patients presented with higher mRALE scores at admission chest radiography compared with White or non-Hispanic patients (adjusted average difference, 1.6; 95% CI: 0.5, 2.7; P < .01). Adjustment for hypothesized mediators revealed that the association between race and/or ethnicity and mRALE scores was mediated by limited English proficiency (P < .01). Conclusion Non-White patients hospitalized with coronavirus disease 2019 infection were more likely to have a higher severity of disease on admission chest radiographs than White or non-Hispanic patients, and increased severity was associated with worse outcomes for all patients. © RSNA, 2020 Online supplemental material is available for this article.

A radiology research interest group of medical students, with the necessary infrastructure and resident leadership, may create a productive environment for research and career development for all p...

Background Angiotensin-converting enzyme 2, a target of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), demonstrates its highest surface expression in the lung, small bowel, and vasculature, suggesting abdominal viscera may be susceptible to injury. Purpose To report abdominal imaging findings in patients with coronavirus disease 2019. Materials and Methods In this retrospective cross-sectional study, patients consecutively admitted to a single quaternary care center from March 27 to April 10, 2020, who tested positive for SARS-CoV-2 were included. Abdominal imaging studies performed in these patients were reviewed, and salient findings were recorded. Medical records were reviewed for clinical data. Univariable analysis and logistic regression were performed. Results A total of 412 patients (average age, 57 years; range, 18 to >90 years; 241 men, 171 women) were evaluated. A total of 224 abdominal imaging studies were performed (radiography, n = 137; US, n = 44; CT, n = 42; MRI, n = 1) in 134 patients (33%). Abdominal imaging was associated with age (odds ratio [OR], 1.03 per year of increase; P = .001) and intensive care unit (ICU) admission (OR, 17.3; P < .001). Bowel-wall abnormalities were seen on 31% of CT images (13 of 42) and were associated with ICU admission (OR, 15.5; P = .01). Bowel findings included pneumatosis or portal venous gas, seen on 20% of CT images obtained in patients in the ICU (four of 20). Surgical correlation (n = 4) revealed unusual yellow discoloration of the bowel (n = 3) and bowel infarction (n = 2). Pathologic findings revealed ischemic enteritis with patchy necrosis and fibrin thrombi in arterioles (n = 2). Right upper quadrant US examinations were mostly performed because of liver laboratory findings (87%, 32 of 37), and 54% (20 of 37) revealed a dilated sludge-filled gallbladder, suggestive of bile stasis. Patients with a cholecystostomy tube placed (n = 4) had negative bacterial cultures. Conclusion Bowel abnormalities and gallbladder bile stasis were common findings on abdominal images of patients with coronavirus disease 2019. Patients who underwent laparotomy often had ischemia, possibly due to small-vessel thrombosis. © RSNA, 2020.

The heterogeneity and continuous genetic adaptation of tumours complicate their detection and treatment via the targeting of genetic mutations. However, hallmarks of cancer such as aberrant protein phosphorylation and calcium-mediated cell signalling provide broadly conserved molecular targets. Here, we show that, for a range of solid tumours, a cyclic octapeptide labelled with a near-infrared dye selectively binds to phosphorylated Annexin A2 (pANXA2), with high affinity at high levels of calcium. Because of cancer-cell-induced pANXA2 expression in tumour-associated stromal cells, the octapeptide preferentially binds to the invasive edges of tumours and then traffics within macrophages to the tumour's necrotic core. As proof-of-concept applications, we used the octapeptide to detect tumour xenografts and metastatic lesions, and to perform fluorescence-guided surgical tumour resection, in mice. Our findings suggest that high levels of pANXA2 in association with elevated calcium are present in the microenvironment of most solid cancers. The octapeptide might be broadly useful for selective tumour imaging and for delivering drugs to the edges and to the core of solid tumours.

Objective: To predict short-term outcomes in hospitalized COVID-19 patients using a model incorporating clinical variables with automated convolutional neural network (CNN) chest radiograph analysis. Methods: A retrospective single center study was performed on patients consecutively admitted with COVID-19 between March 14 and April 21 2020. Demographic, clinical and laboratory data were collected, and automated CNN scoring of the admission chest radiograph was performed. The two outcomes of disease progression were intubation or death within 7 days and death within 14 days following admission. Multiple imputation was performed for missing predictor variables and, for each imputed data set, a penalized logistic regression model was constructed to identify predictors and their functional relationship to each outcome. Cross-validated area under the characteristic (AUC) curves were estimated to quantify the discriminative ability of each model. Results: 801 patients (median age 59; interquartile range 46–73 years, 469 men) were evaluated. 36 patients were deceased and 207 were intubated at 7 days and 65 were deceased at 14 days. Cross-validated AUC values for predictive models were 0.82 (95% CI, 0.79–0.86) for death or intubation within 7 days and 0.82 (0.78–0.87) for death within 14 days. Automated CNN chest radiograph score was an important variable in predicting both outcomes. Conclusion: Automated CNN chest radiograph analysis, in combination with clinical variables, predicts short-term intubation and death in patients hospitalized for COVID-19 infection. Chest radiograph scoring of more severe disease was associated with a greater probability of adverse short-term outcome. Advances in knowledge: Model-based predictions of intubation and death in COVID-19 can be performed with high discriminative performance using admission clinical data and convolutional neural network-based scoring of chest radiograph severity.

Objectives: The purpose of this study is to compare the role of bronchial artery embolization (BAE) in hemoptysis due to malignant and non-malignant etiologies. Material and Methods: Data from patients who underwent BAE at a tertiary care center from October 2002 to 2018 were retrospectively reviewed. Variables evaluated include procedural indication, technical success, clinical success, re-embolization, intensive care unit (ICU) admission, length of stay, and thirty-day readmission. Categorical and continuous variables were analyzed using Pearson’s Chi-squared and two sample t-tests, respectively. Post-procedure survival and re-embolization were analyzed using Kaplan–Meier curves and Cox proportional hazard models. Results: 114 BAE procedures from 93 unique patients with hemoptysis were identified, with 29.8% of procedures being performed for hemoptysis secondary to malignancy and 70.2% for benign causes. The technical and clinical success rates of the procedure were similar between benign and malignant etiologies (benign/malignant: 92.5% vs. 91.2% and 82.5% vs. 73.5%, respectively). There were no statistically significant differences in rates of need for re-embolization, ICU admission, 30-day readmission, mean hospital length of stay, or mortality between benign and malignant groups. Clinically successful embolization was protective against death (HR = 0.19, P < 0.001) and re-embolization (HR = 0.04, P = 0.001), while higher American Society of Anesthesiologists’ (ASA) score, female sex, and primary pulmonary malignancy were associated with risk of death. Conclusion: While patients with a malignant cause of hemoptysis had an increased risk of mortality and decreased survival time, BAE for malignant hemoptysis is effective with outcomes comparable to that for benign hemoptysis as indicated by high clinical and technical success rates and low rates of re-embolization.

To identify the variables associated with patient discharge disposition to optimize postprocedural care and discharge planning following lower extremity arterial interventions for peripheral artery disease (PAD).The 2014-2017 American College of Surgeons National Surgical Quality Improvement Program database was queried using current procedural terminology codes for endovascular infrainguinal interventions for PAD. The main outcome variable of interest was nonhome discharge. Covariates included patient sociodemographic variables, age quartile (upper quartile, ≥77 years), comorbidities (diabetes, renal disease, bleeding disorder, congestive heart failure [CHF], and chronic obstructive pulmonary disease), presence of an open wound before a procedure, type of procedure, operative time, symptom severity, American Society of Anesthesiologists class, and baseline functional status. Univariate analysis and multivariate logistic regression were performed on Stata/SE 15.1.A total of 3,190 patients met the inclusion criteria, of whom 664 (20.8%) had nonhome discharge. Multivariate regression revealed that age (odds ratio [OR], 1.9 for the upper age quartile [77 years]; 95% confidence interval [CI], 1.46-2.50), operative time (OR, 1.2 per increase in quartile; 95% CI, 1.09-1.30), preoperative wound (OR, 1.5; 95% CI, 1.24-1.90), renal failure (OR, 1.7; 95% CI, 1.30-2.14), CHF (OR, 2.2; 95% CI, 1.51-3.24), symptom severity (OR, 1.7; 95% CI, 1.46-1.98), and independent functional status (OR, 0.74; 95% CI, 0.59-0.92; P = .007) were associated with nonhome discharge. All P values were ≤.001 unless otherwise stated.Prolonged procedural time, the presence of preprocedural wound and patient comorbidities, symptomatology, and baseline functional status may be used to identify patients who will require a nonhome discharge and early discharge planning.

Immunotherapy has revolutionized the contemporary oncology landscape, with durable responses possible across a range of cancer types. However, the majority of cancer patients do not respond to immunotherapy due to numerous immunosuppressive barriers. Efforts to overcome these barriers and increase systemic immunotherapy efficacy have sparked interest in the local intratumoral delivery of immune stimulants to activate the local immune response and subsequently drive systemic tumor immunity. While clinical evaluation of many therapeutic candidates is ongoing, development is hindered by a lack of imaging confirmation of local delivery, insufficient intratumoral drug distribution, and a need for repeated injections. The use of polymeric drug delivery systems, which have been widely used as platforms for both image guidance and controlled drug release, holds promise for delivery of intratumoral immunoadjuvants and the development of an in situ cancer vaccine for patients with metastatic cancer. In this review, we explore the current state of the field for intratumoral delivery and methods for optimizing controlled drug release, as well as practical considerations for drug delivery design to be optimized for clinical image guided delivery particularly by CT and ultrasound.

To assess the utility of the radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, and location relative to polar lines (RENAL) nephrometry scoring system at predicting adverse events and outcomes in percutaneous microwave ablation (MWA) of renal tumors.A retrospective review of 116 patients who underwent MWA from 2004 to 2018 at 2 large university hospitals was conducted. Patient demographics and tumor characteristics were collected. The RENAL nephrometry scores were calculated, and procedure-related adverse events were stratified into minor and major (the Society of Interventional Radiology classification of class C or higher). Technical and oncologic outcomes were based on follow-up magnetic resonance imaging and computed tomography scans after ablation.The mean RENAL score was 6.6 (range, 4-11), and the mean tumor size was 24 mm. Follow-up ranged between 16 and 161 weeks (median, 50 weeks; mean, 65 weeks). Oncologic control was achieved in 96% (n = 111) of patients. The major and minor adverse event rates were 8.6% (n = 10) and 17% (n = 19), respectively. The mean RENAL score for patients with recurrent and/or residual tumor (8.2 ± 2.7) was higher than that for patients without disease recurrence (6.5 ± 3.5, P = .05). However, in a multivariate analysis, the RENAL score was not found to be an independent predictor of oncologic outcomes (odds ratio, 1.548; P = .092).The RENAL nephrometry score has minimal utility for predicting outcomes and adverse events in MWA of renal tumors. The inconsistent nature of RENAL nephrometry scoring in percutaneous ablation procedures underscores the need for an ablation-specific risk stratification system.

BACKGROUND. Previous studies compared CT findings of COVID-19 pneumonia with those of other infections; however, to our knowledge, no studies to date have included noninfectious organizing pneumonia (OP) for comparison. OBJECTIVE. The objectives of this study were to compare chest CT features of COVID-19, influenza, and OP using a multireader design and to assess the performance of radiologists in distinguishing between these conditions. METHODS. This retrospective study included 150 chest CT examinations in 150 patients (mean [± SD] age, 58 ± 16 years) with a diagnosis of COVID-19, influenza, or non-infectious OP (50 randomly selected abnormal CT examinations per diagnosis). Six thoracic radiologists independently assessed CT examinations for 14 individual CT findings and for Radiological Society of North America (RSNA) COVID-19 category and recorded a favored diagnosis. The CT characteristics of the three diagnoses were compared using random-effects models; the diagnostic performance of the readers was assessed. RESULTS. COVID-19 pneumonia was significantly different (p < .05) from influenza pneumonia for seven of 14 chest CT findings, although it was different (p < .05) from OP for four of 14 findings (central or diffuse distribution was seen in 10% and 7% of COVID-19 cases, respectively, vs 20% and 21% of OP cases, respectively; unilateral distribution was seen in 1% of COVID-19 cases vs 7% of OP cases; non-tree-in-bud nodules was seen in 32% of COVID-19 cases vs 53% of OP cases; tree-in-bud nodules were seen in 6% of COVID-19 cases vs 14% of OP cases). A total of 70% of cases of COVID-19, 33% of influenza cases, and 47% of OP cases had typical findings according to RSNA COVID-19 category assessment (p < .001). The mean percentage of correct favored diagnoses compared with actual diagnoses was 44% for COVID-19, 29% for influenza, and 39% for OP. The mean diagnostic accuracy of favored diagnoses was 70% for COVID-19 pneumonia and 68% for both influenza and OP. CONCLUSION. CT findings of COVID-19 substantially overlap with those of influenza and, to a greater extent, those of OP. The diagnostic accuracy of the radiologists was low in a study sample that contained equal proportions of these three types of pneumonia. CLINICAL IMPACT. Recognized challenges in diagnosing COVID-19 by CT are furthered by the strong overlap observed between the appearances of COVID-19 and OP on CT. This challenge may be particularly evident in clinical settings in which there are substantial proportions of patients with potential causes of OP such as ongoing cancer therapy or autoimmune conditions.

The COVID-19 pandemic has led to delays in cancer diagnosis, in part due to postponement of cancer screening. We used Google Trends data to assess public attention to cancer screening during the first peak of the COVID-19 pandemic. Search volume for terms related to established cancer screening tests (“colonoscopy,” “mammogram,” “lung cancer screening,” and “pap smear”) showed a marked decrease of up to 76% compared to the pre-pandemic period, a significantly greater drop than for search volume for terms denoting common chronic diseases. Maintaining awareness of cancer screening during future public health crises may decrease delays in cancer diagnosis.

The COVID-19 pandemic has challenged the capacity of interventional radiology departments worldwide to effectively treat COVID-19 and non-COVID-19 patients while preventing disease transmission among patients and healthcare workers. In this review, we describe the various data driven infection control measures implemented by the interventional radiology department of a large tertiary care center in the United States including the use and novel re-use of personal protective equipment, COVID-19 testing strategies, modifications in procedural workflows and the leveraging of telehealth visits. Herein, we provide effective triage, procedural, and management algorithms that may guide other interventional radiology departments during the ongoing COVID-19 pandemic and in future infectious disease outbreaks.

To determine the pathologic response of computed tomography-guided percutaneous microwave ablation as bridging therapy for patients with hepatocellular carcinoma awaiting liver transplant, and its subsequent effect on survival.A single-center retrospective analysis was conducted on 62 patients (M:F = 50:12) with mean age of 59.6 years ± 7.2 months (SD). Sixty-four total MWA procedures were performed for hepatocellular carcinomas within Milan criteria as bridging therapy to subsequent orthotopic liver transplant between August 2014 and September 2018. The pathology reports of the explanted livers were reviewed to assess for residual disease. Residual disease was categorized as complete or incomplete necrosis. Patient demographics, tumor/procedural characteristics, and laboratory values were evaluated. Survival from time of ablation and time of transplantation were recorded and compared between cohorts using log rank tests.The mean tumor size was 2.4 cm ± 0.7 cm (SD), (range = 1-4.6 cm). 32 (50%) cases required hydrodissection. Histopathologic necrosis was seen in 66% of cases at time of liver transplantation. Median time to liver transplant post-MWA was 12.6 months. [IQR = 8.6-14.8 months]. The median survival from ablation was 60.8 months [IQR = 45.5-73.7 months], and the median survival from transplant was 49.3 months [IQR = 33.7-60.1 months]. There was no significant difference in survival for patients with complete versus incomplete necrosis from ablation or liver transplant (p = 0.49, p = 0.46, respectively).Computed tomography-guided percutaneous microwave ablation is an effective bridge to orthotopic liver transplantation for patients with hepatocellular carcinoma.Level 3, non-randomized controlled cohort study/follow-up study.

Rationale and Objectives While affiliated imaging centers play an important role in healthcare systems, little is known of how their operations are impacted by the COVID-19 pandemic. Our goal was to investigate imaging volume trends during the pandemic at our large academic hospital compared to the affiliated imaging centers. Materials and Methods This was a descriptive retrospective study of imaging volume from an academic hospital (main hospital campus) and its affiliated imaging centers from January 1 through May 21, 2020. Imaging volume assessment was separated into prestate of emergency (SOE) period (before SOE in Massachusetts on March 10, 2020), “post-SOE” period (time after “nonessential” services closure on March 24, 2020), and “transition” period (between pre-SOE and post-SOE). Results Imaging volume began to decrease on March 11, 2020, after hospital policy to delay nonessential studies. The average weekly imaging volume during the post-SOE period declined by 54% at the main hospital campus and 64% at the affiliated imaging centers. The rate of imaging volume recovery was slower for affiliated imaging centers (slope = 6.95 for weekdays) compared to main hospital campus (slope = 7.18 for weekdays). CT, radiography, and ultrasound exhibited the lowest volume loss, with weekly volume decrease of 41%, 49%, and 53%, respectively, at the main hospital campus, and 43%, 61%, and 60%, respectively, at affiliated imaging centers. Mammography had the greatest volume loss of 92% at both the main hospital campus and affiliated imaging centers. Conclusion Affiliated imaging center volume decreased to a greater degree than the main hospital campus and showed a slower rate of recovery. Furthermore, the trend in imaging volume and recovery were temporally related to public health announcements and COVID-19 cases.

N95 filtering facepiece respirators (FFR) and surgical masks are essential in reducing airborne disease transmission, particularly during the COVID-19 pandemic. However, currently available FFR's and masks have major limitations, including masking facial features, waste, and integrity after decontamination. In a multi-institutional trial, we evaluated a transparent, elastomeric, adaptable, long-lasting (TEAL) respirator to evaluate success of qualitative fit test with user experience and biometric evaluation of temperature, respiratory rate, and fit of respirator using a novel sensor. There was a 100% successful fit test among participants, with feedback demonstrating excellent or good fit (90% of participants), breathability (77.5%), and filter exchange (95%). Biometric testing demonstrated significant differences between exhalation and inhalation pressures among a poorly fitting respirator, well-fitting respirator, and the occlusion of one filter of the respirator. We have designed and evaluated a transparent elastomeric respirator and a novel biometric feedback system that could be implemented in the hospital setting., NIH(Grants K23DA044874, R44DA051106), NIH (Grants K23DA044874, R44DA051106, 5T32DK007191-4)

The purpose of this article was to report the utility of computed tomography (CT) for detecting unsuspected cases of Coronavirus disease 2019 (COVID-19) and the utility of the Radiological Society of North America (RSNA)/Society of Thoracic Radiology (STR)/American College of Radiology (ACR) consensus guidelines for COVID-19 reporting.A total of 22 patients of the 156 reverse transcriptase polymerase chain reaction confirmed COVID-19 patients who were hospitalized between March 27, 2020 and March 31, 2020 at our quaternary care academic medical center and who underwent CT imaging within 1 week of admission were included in this retrospective study. Demographics and clinical data were extracted from the electronic medical record system. Two thoracic radiologists independently categorized each CT study on the basis of RSNA/STR/ACR consensus guidelines. Disagreement in categorization was resolved by consensus discussion with a third thoracic radiologist.At the time of imaging, 16 patients (73%) were suspected of COVID-19, and 6 patients (27%) were not. Common symptoms at presentation were fever (73%), cough (77%), and gastrointestinal symptoms (59%). An overall 63% of suspected COVID-19 patients exhibited shortness of breath, whereas 0 unsuspected COVID-19 patients did (P=0.02). On the basis of the RSNA consensus guidelines, 68%, 18%, 9%, and 5% of studies were categorized as "typical appearance," "indeterminate appearance," "atypical appearance," and "negative for pneumonia," respectively. There was no difference of category distribution between suspected and unsuspected COVID-19 patients (P=0.20), with "typical appearance" being the most prevalent in both (69% vs. 67%, respectively).It is important to recognize imaging features of COVID-19 pneumonia even in unsuspected patients. Implementation of the RSNA/STR/ACR consensus guidelines may increase consistency of reporting and convey the level of suspicion for COVID-19 to other health care providers, with "typical appearance" especially warranting further attention.

PURPOSE: The purpose of this article was to report the utility of computed tomography (CT) for detecting unsuspected cases of Coronavirus disease 2019 (COVID-19) and the utility of the Radiological Society of North America (RSNA)/Society of Thoracic Radiology (STR)/American College of Radiology (ACR) consensus guidelines for COVID-19 reporting. MATERIALS AND METHODS: A total of 22 patients of the 156 reverse transcriptase polymerase chain reaction confirmed COVID-19 patients who were hospitalized between March 27, 2020 and March 31, 2020 at our quaternary care academic medical center and who underwent CT imaging within 1 week of admission were included in this retrospective study. Demographics and clinical data were extracted from the electronic medical record system. Two thoracic radiologists independently categorized each CT study on the basis of RSNA/STR/ACR consensus guidelines. Disagreement in categorization was resolved by consensus discussion with a third thoracic radiologist. RESULTS: At the time of imaging, 16 patients (73%) were suspected of COVID-19, and 6 patients (27%) were not. Common symptoms at presentation were fever (73%), cough (77%), and gastrointestinal symptoms (59%). An overall 63% of suspected COVID-19 patients exhibited shortness of breath, whereas 0 unsuspected COVID-19 patients did (P=0.02). On the basis of the RSNA consensus guidelines, 68%, 18%, 9%, and 5% of studies were categorized as "typical appearance," "indeterminate appearance," "atypical appearance," and "negative for pneumonia," respectively. There was no difference of category distribution between suspected and unsuspected COVID-19 patients (P=0.20), with "typical appearance" being the most prevalent in both (69% vs. 67%, respectively). CONCLUSIONS: It is important to recognize imaging features of COVID-19 pneumonia even in unsuspected patients. Implementation of the RSNA/STR/ACR consensus guidelines may increase consistency of reporting and convey the level of suspicion for COVID-19 to other health care providers, with "typical appearance" especially warranting further attention.

Objectives: During the COVID-19 pandemic, there was a perceived increase in the number of cholecystostomy tube placements. We have retrospectively analyzed the incidence and outcomes of cholecystostomy tube placement during the COVID-19 pandemic surge. Material and Methods: Cholecystostomy tube placement and overall interventional radiology (IR) case volume were analyzed at our tertiary care center during the pandemic (March 15, 2020–July 30, 2020) and compared to the same time period in 2019. In addition, an age- and gender-matched control study of outcomes for 40 patients (25 from our home institution and 15 from our affiliated hospitals) grouped by COVID-19 status who received percutaneous cholecystostomy tubes between March 15, 2020, and July 30, 2020, was performed. Results: We observed a significant increase in relative cholecystostomy tube volume during the pandemic, despite a decrease in total IR case volume. There was no significant difference in pre- or post-procedural laboratory data, vital signs, imaging, or mortality between COVID-positive and COVID-negative patients who received cholecystostomy tubes. Conclusion: Percutaneous cholecystostomy tube placement is likely a safe treatment for acalculous cholecystitis in patients with COVID-19 with equivalent outcomes to patients without COVID-19.

Purpose: Our goal was to review the incidence and outcomes of cholecystostomy tube placement during the COVID pandemic as compared to matched controls. Materials and Methods: Monthly interventional radiology (IR) case volume was evaluated during the COVID pandemic through July 30, 2020, and was compared to monthly IR case volume during the same time period in 2019. A retrospective review of 40 patients who received percutaneous cholecystostomy tubes between March 2020 and July 2020 (first COVID pandemic peak in Boston, MA) was compared in a propensity matched controlled study. 14 COVID-positive patients were matched to 26 control patients who received a cholecystostomy tube. Outcomes such as positive cholecystostomy tube microbiology, pre-procedural ICU status, and death were evaluated. Results: During March to July 30, 2020, cholecystostomy tube placement constituted 0.43%, average 6 (range 2-10) cases/month of 1389 (range 672-1777) cases/month, whereas in the year prior for the same period it constituted 0.28%, 5.8 (range 4-8) cases/month of 2103 (range 1998-2146) cases/month. We find the average age was 66.5 ± 17.7 (SD) for COVID-negative and 66.0 ± 17.7 (SD) years for COVID-positive patients. Pre-procedure 19% (5/26) of COVID-negative patients and 50% (7/14) of COVID-positive patients were intubated at the time of placement, P = 0.04. Post-procedure, 54% (14/26) of COVID-negative patients and 50% (7/14) of COVID-positive patients had positive cholecystostomy tube fluid microbiology cultures, P = 0.82. 38% (10/26) of COVID-negative patients and 57% (8/14) of COVID-positive patients were in the ICU at the time of placement, P = 0.26. 23% (6/26) of the COVID-negative patients and 36% (5/14) of COVID-positive patients died post-procedure, P = 0.41. 15.4% (4/26) COVID-negative and 14.3% (2/14) of COVID-positive patients had any complications reported, P = 0.93. Conclusions: During the COVID-19 pandemic, we observed a relative increase in the number of cholecystostomy tube referrals despite a drop in total IR case volume. There were no significant differences in post-procedure long-term outcomes and the microbial culture results in our matched control review. Our study suggests that this perceived increase in cholecystostomy tube placements is not secondary to unique COVID pathophysiology, but rather a persistent incidence of acalculous cholecystitis in the setting of chronic ICU stays seen during the COVID pandemic. With the continuation of the pandemic, cholecystostomy tube placement incidence may increase with continued COVID patient care and chronic ICU stays for these patients.

Aim: CaCO3 nanoparticles (nano-CaCO3) can neutralize the acidic pHe of solid tumors, but the lack of intrinsic imaging signal precludes noninvasive monitoring of pH-perturbation in tumor microenvironment. We aim to develop a theranostic version of nano-CaCO3 to noninvasively monitor pH modulation and subsequent tumor response. Materials & methods: We synthesized ferromagnetic core coated with CaCO3 (magnetite CaCO3). Magnetic resonance imaging (MRI) was used to determine the biodistribution and pH modulation using murine fibrosarcoma and breast cancer models. Results: Magnetite CaCO3-MRI imaging showed that nano-CaCO3 rapidly raised tumor pHe, followed by excessive tumor-associated acid production after its clearance. Continuous nano-CaCO3 infusion could inhibit metastasis. Conclusion: Nano-CaCO3 exposure induces tumor metabolic reprogramming that could account for the failure of previous intermittent pH-modulation strategies to achieve sustainable therapeutic effect.

Antacids are crucial in the treatment of gastro-esophageal reflux disease and peptic ulcers. Antacids based on the calcite phase of bulk calcium carbonate have been the standard for over fifty years. More recent research has shown that nanomaterial forms of such bulk materials often have improved properties. However, the metastable vaterite form of calcium carbonate is particularly difficult to synthesize as a nanomaterial, and thus has not been extensively studied. Here, we describe the synthesis of these particles and investigate them for antacid applications. Experimental and computational approaches show that nanoscale vaterite particles maintain neutral gastric pH values three times longer than commercial antacids.

Enhanced glycolysis and poor perfusion in most solid malignant tumors create an acidic extracellular environment, which enhances tumor growth, invasion, and metastasis. Complex molecular systems have been explored for imaging and treating these tumors. Here, we report the development of a small molecule, LS662, that emits near-infrared (NIR) fluorescence upon protonation by the extracellular acidic pH environment of diverse solid tumors. Protonation of LS662 induces selective internalization into tumor cells and retention in the tumor microenvironment. Noninvasive NIR imaging demonstrates selective retention of the pH sensor in diverse tumors, and two-photon microscopy of ex vivo tumors reveals significant retention of LS662 in tumor cells and the acid tumor microenvironment. Passive and active internalization processes combine to enhance NIR fluorescence in tumors over time. The low background fluorescence allows tumors to be detected with high sensitivity, as well as dead or dying cells to be delineated from healthy cells. In addition to demonstrating the feasibility of using small molecule pH sensors to image multiple aggressive solid tumor types via a protonation-induced internalization and retention pathway, the study reveals the potential of using LS662 to monitor treatment response and tumor-targeted drug delivery.

Background Parenchymal findings in COVID-19 pneumonia on computed tomography (CT) have been well characterized. However, the role of pulmonary vascular pathology in COVID-19 pneumonia is still not well understood. Purpose To investigate pulmonary vascular abnormalities on CT pulmonary angiography in patients with COVID-19 pneumonia. Materials and Methods In this retrospective study, 48 patients with RT-PCR confirmed COVID-19 infection who had undergone CT pulmonary angiography between 3/22/20 and 4/5/20 in our large urban health care system were included. Patient demographics and clinical data were collected through the electronic medical record system. Twenty-five patients underwent dual energy CT (DECT) as part of the standard CT pulmonary angiogram protocol at a subset of the hospitals. Two thoracic radiologists independently assessed all studies. Disagreement in assessment was resolved by consensus discussion with a third thoracic radiologist. Results Of the 48 patients, 45 patients required admission, with 18 admitted to the ICU, and 13 requiring intubation. Seven patients (15%) were found to have pulmonary emboli. Dilated vessels were seen in 41 cases (85%), with 38 (78%) and 27 (55%) of cases demonstrating vessel enlargement within and outside of lung opacities, respectively. Dilated distal vessels extending to the pleura and fissures were seen in 40 cases (82%) and 30 cases (61%), respectively. On DECT, mosaic perfusion pattern was observed in 24 cases (96%), regional hyperemia overlapping with areas of pulmonary opacities or immediately surrounding the opacities were seen in 13 cases (52%), opacities associated with corresponding oligemia were seen in 24 cases (96%), and hyperemic halo was seen in 9 cases (36%). Conclusion Pulmonary vascular abnormalities such as vessel enlargement and regional mosaic perfusion patterns are common in COVID-19 pneumonia. Perfusion abnormalities are also frequently observed at DECT in COVID-19 pneumonia and may suggest an underlying vascular process.

Introduction Owing to its capacity to perform remote assessments, telemedicine is rising as a new force in chronic obstructive pulmonary disease (COPD) management. We conducted an eight month randomised-controlled-trial to study the effect of an automated telemedicine intervention on patients’ time-to-hospitalisation. Methods A total of 168 patients with a diagnosis of COPD in the past 24 months were enrolled to receive the intervention at a primary care clinic. The treatment group received daily phone messages from an automated system asking them to report if they were breathing better than, worse than, or the same as the day prior. Patients reported their breathing status by responding to the text message or call. If a patient reported breathing worse, an alert was sent directly to that patient’s provider within the clinic. The control group received the same daily phone messages as the treatment group. However, no proactive breathing alerts were ever generated to the provider for these subjects. The primary outcome was the subjects’ time-to-first-COPD-related hospitalisation following the start of messages. Results The treatment group’s time-to-hospitalisation was significantly different than the control group’s with a hazard ratio of 2.36 (95% confidence interval 1.02–5.45, p = 0.0443). The number needed-to-treat ratio was 8.62. Subject engagement consistently ranged between 60% and 75%. The treatment group received both proactive monitoring and follow-up care from the providers. Discussion Active monitoring with provider feedback enables the detection of exacerbation events early enough for subjects to avoid admissions. The use of non-smartphone interventions reduces barriers to care presented by more complicated and expensive technologies. This intervention represents a simple, innovative, and inexpensive tool for improved COPD management.

Comorbidities and socioeconomic barriers often limit patient adherence and self-management with hemodialysis. Missed sessions, often associated with communication barriers, can result in emergency dialysis and avoidable hospitalizations. This proof of concept study explored using a novel digital-messaging platform, EpxDialysis, to improve patient-to-dialysis center communication via widely available text messaging and telephone technology. A randomized controlled trial was conducted through Washington University-affiliated hemodialysis centers involving ESRD patients with poor attendance, defined as missing 2–6 sessions over the preceding 12 weeks. A cross-over study design evaluated appointment adherence between intervention and control groups. Comparing nonadherence rates eight weeks prior to enrollment, median appointment adherence after using the system increased by 75%, and median number of unintended hospitalization days fell by 31%. A conservative cost-benefit analysis of EpxDialysis demonstrates a 1:36 savings ratio from appointment adherence. EpxDialysis is a low-risk, cost-effective, intervention for increasing hemodialysis adherence in high-risk patients, especially at centers caring for vulnerable and low-income patients.

Background: Medication adherence remains a difficult problem to both assess and improve in patients. It is a multifactorial problem that goes beyond the commonly cited reason of forgetfulness. To date, eHealth (also known as mHealth and telehealth) interventions to improve medication adherence have largely been successful in improving adherence. However, interventions to date have used time- and cost-intensive strategies or focused solely on medication reminding, leaving much room for improvement in using a modality as flexible as eHealth. Objective: Our objective was to develop and implement a fully automated short message service (SMS)-based medication adherence system, EpxMedTracking, that reminds patients to take their medications, explores reasons for missed doses, and alerts providers to help address problems of medication adherence in real time. Methods: EpxMedTracking is a fully automated bidirectional SMS-based messaging system with provider involvement that was developed and implemented through Epharmix, Inc. Researchers analyzed 11 weeks of de-identified data from patients cared for by multiple provider groups in routine community practice for feasibility and functionality. Patients included were those in the care of a provider purchasing the EpxMedTracking tool from Epharmix and were enrolled from a clinic by their providers. The primary outcomes assessed were the rate of engagement with the system, reasons for missing doses, and self-reported medication adherence. Results: Of the 25 patients studied over the 11 weeks, 3 never responded and subsequently opted out or were deleted by their provider. No other patients opted out or were deleted during the study period. Across the 11 weeks of the study period, the overall weekly engagement rate was 85.9%. There were 109 total reported missed doses including “I forgot” at 33 events (30.3%), “I felt better” at 29 events (26.6%), “out of meds” at 20 events (18.4%), “I felt sick” at 19 events (17.4%), and “other” at 3 events (2.8%). We also noted an increase in self-reported medication adherence in patients using the EpxMedTracking system. Conclusions: EpxMedTracking is an effective tool for tracking self-reported medication adherence over time. It uniquely identifies actionable reasons for missing doses for subsequent provider intervention in real time based on patient feedback. Patients enrolled on EpxMedTracking also self-report higher rates of medication adherence over time while on the system. [JMIR Res Protoc 2017;6(5):e87]

The acidic extracellular environment of tumors potentiates their aggressiveness and metastasis, but few methods exist to selectively modulate the extracellular pH (pHe) environment of tumors. Transient flushing of biological systems with alkaline fluids or proton pump inhibitors is impractical and nonselective. Here we report a nanoparticles-based strategy to intentionally modulate the pHe in tumors. Biochemical simulations indicate that the dissolution of calcium carbonate nanoparticles (nano-CaCO3) dissolution in vivo increases pH asymptotically to 7.4. We developed two independent facile methods to synthesize monodisperse non-doped vaterite nano-CaCO3 with distinct size range between 20 and 300 nm. Using murine models of cancer, we demonstrate that the selective accumulation of nano-CaCO3 in tumors increases tumor pH over time. The associated induction of tumor growth stasis is putatively interpreted as a pHe increase. This study establishes an approach to prepare nano-CaCO3 over a wide particle size range, a formulation that stabilizes the nanomaterials in aqueous solutions, and a pH-sensitive nano-platform capable of modulating the acidic environment of cancer for potential therapeutic benefits.