Faculty Bibliography

OBJECTIVE:To evaluate the impact of structured recommendations on follow-up completion for incidental lung nodules (ILNs). METHODS:Patients with ILNs before and after implementation of structured Fleischner recommendations and electronic tracking were sampled randomly. The cohorts were compared for imaging follow-up. Multivariable logistic regression was used to assess appropriate follow-up and loss to follow-up, with independent variables including use of structured recommendations or tracking, age, gender, race, ethnicity, setting of the index test (inpatient, outpatient, emergency department), smoking history, and nodule features. RESULTS:In all, 1,301 patients met final inclusion criteria, including 255 patients before and 1,046 patients after structured recommendations or tracking. Baseline differences were found in the pre- and postintervention groups, with smaller ILNs and younger age after implementing structured recommendations. Comparing pre- versus postintervention outcomes, 40.0% (100 of 250) versus 29.5% (309 of 1,046) of patients had no follow-up despite Fleischner indications for imaging (P = .002), and among the remaining patients, 56.6% (82 of 145) versus 75.0% (553 of 737) followed up on time (P < .001). Delayed follow-up was more frequent before intervention. Differences postintervention were mostly accounted for by nodules ≤ 8 mm in the outpatient setting (P < .001). In multivariable analysis, younger age, White race, outpatient setting, and larger nodule size showed significant association with appropriate follow-up completion (P < .015), but structured recommendations did not. Similar results applied for loss to follow-up. DISCUSSION/CONCLUSIONS:Consistent use of structured reporting is likely key to mitigate selection bias when benchmarking rates of appropriate follow-up of ILN. Emergency department patients and inpatients are at high risk of missed or delayed follow-up despite structured recommendations.

OBJECTIVE:To evaluate the inter-observer consistency for subsolid pulmonary nodule radiomic features. MATERIALS AND METHODS/METHODS:Subsolid nodules were selected by reviewing radiology reports of CT examinations performed December 1, 2015 to April 1, 2016. Patients with CTs at two time points were included in this study. There were 55 patients with subsolid nodules, of whom 14 had two nodules. Of 69 subsolid nodules, 66 were persistent at the second time point, yielding 135 lesions for segmentation. Two thoracic radiologists and an imaging fellow segmented the lesions using a semi-automated volumetry algorithm (Syngo.via Vb20, Siemens). Coefficient of variation (CV) was used to assess consistency of 91 quantitative measures extracted from the subsolid nodule segmentations, including first and higher order texture features. The accuracy of segmentation was visually graded by an experienced thoracic radiologist. Influencing factors on radiomic feature consistency and segmentation accuracy were assessed using generalized estimating equation analyses and the Exact Mann-Whitney test. RESULTS:Mean patient age was 71 (38-93 years), with 39 women and 16 men. Mean nodule volume was 1.39mL, range .03-48.2mL, for 135 nodules. Several radiomic features showed high inter-reader consistency (CV<5%), including entropy, uniformity, sphericity, and spherical disproportion. Descriptors such as surface area and energy had low consistency across inter-reader segmentations (CV>10%). Nodule percent solid component and attenuation influenced inter-reader variability of some radiomic features. The presence of contrast did not significantly affect the consistency of subsolid nodule radiomic features. Near perfect segmentation, within 5% of actual nodule size, was achieved in 68% of segmentations, and very good segmentation, within 25% of actual nodule size, in 94%. Morphologic features including nodule margin and shape (each p <0.01), and presence of air bronchograms (p = 0.004), bubble lucencies (p = 0.02) and broad pleural contact (p < 0.01) significantly affected the probability of near perfect segmentation. Stroke angle (p = 0.001) and length (p < 0.001) also significantly influenced probability of near perfect segmentation. CONCLUSIONS:The inter-observer consistency of radiomic features for subsolid pulmonary nodules varies, with high consistency for several features, including sphericity, spherical disproportion, and first and higher order entropy, and normalized non-uniformity. Nodule morphology influences the consistency of subsolid nodule radiomic features, and the accuracy of subsolid nodule segmentation.

INTRODUCTIONS: ECMO is a treatment modality known to alter drug pharmacokinetics (PK). The purpose of this study was to determine the impact of the Quadrox-i pediatric and adult oxygenators on the PK of peramivir (PRV) in contemporary ECMO circuits.
METHOD(S):Two 1/4-in. and two 3/8-in. closed loop ECMO circuits were prepared using custom tubing with polyvinylchloride and superTygon (Medtronic Inc., Minneapolis, MN) and a Quadrox-i adult or pediatric oxygenator (Maquet). Additionally, two 1/4-in. and two 3/8-in. closed loop ECMO circuits wer assembled without an oxygenator in series. The circuits were carbon dioxide primed, evacuated, and then crystalloid primed. After debubbling the circuit, 50 mL of 5% albumin was added and then displaced with the priming solution (whole blood), tromethamine, heparin, and calcium gluconate. The circuit pH was adjusted to a range of 7.35-7.45. The closed-loop design was established by connecting the ends of the arterial and venous cannulae to a reservoir bag, allowing continuous flow of the priming fluid around the circuit. PRV was added to the circuit and levels were obtained pre-and post-oxygenator at the following time intervals; 5 mins, 1, 2, 3, 4, 5, 6, 8, 12, and 24 hrs. PRV was also maintained in a glass vial and samples obtained at the same time periods for control purposes. PRV samples were analyzed by liquid chromatography tandem mass spectrometry.
RESULT(S): For the 3/8-in. circuits with an oxygenator, there was < 15% PRV loss during the study period. For the 3/8-in. circuits without an oxygenator, there was < 3% PRV loss during the study period. For the 1/4-in. circuits with an oxygenator, there was < 15% PRV loss during the study period. For the 1/4-in. circuits without an oxygenator, there was < 3% PRV loss during the study period.
CONCLUSION(S): There was no significant PRV loss over the 24-hour study period in either the 1/4-in. or 3/8-in circuit, regardless of the presence of the oxygenator. The concentrations obtained pre- and post-oxygenator appeared to approximate each other suggesting there may be no drug loss via the oxygenator. This preliminary data suggests PRV dosing may not need to be adjusted for concern of drug loss via the oxygenator. Additional single and multiple dose studies are needed to validate these findings

Chest pain is a common reason that patients may present for evaluation in both ambulatory and emergency department settings, and is often of musculoskeletal origin in the former. Chest wall syndrome collectively describes the various entities that can contribute to chest wall pain of musculoskeletal origin and may affect any chest wall structure. Various imaging modalities may be employed for the diagnosis of nontraumatic chest wall conditions, each with variable utility depending on the clinical scenario. We review the evidence for or against use of various imaging modalities for the diagnosis of nontraumatic chest wall pain. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Diffuse lung disease, frequently referred to as interstitial lung disease, encompasses numerous disorders affecting the lung parenchyma. The potential etiologies of diffuse lung disease are broad with several hundred established clinical syndromes and pathologies currently identified. Imaging plays a critical role in diagnosis and follow-up of many of these diseases, although multidisciplinary discussion is the current standard for diagnosis of several DLDs. This document aims to establish guidelines for evaluation of diffuse lung diseases for 1) initial imaging of suspected diffuse lung disease, 2) initial imaging of suspected acute exacerbation or acute deterioration in cases of confirmed diffuse lung disease, and 3) clinically indicated routine follow-up of confirmed diffuse lung disease without acute deterioration. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Extracorporeal membrane oxygenation (ECMO) is known to alter drug pharmacokinetics (PK). The PK changes can result from drug binding to the oxygenator, alterations in clearance, and drug sequestration but the published literature is outdated. There is limited data regarding the impact of the oxygenator on drug changes in ECMO circuits in comparison to the other components of the ECMO circuit. The purpose of this study was to determine the impact of the Quadrox-i pediatric and adult oxygenators on the PK of peramivir (PRV) in contemporary ECMO circuits. Two of both 1/4-in. and 3/8-in. closed loop ECMO circuits were prepared with a Quadrox-i adult or pediatric oxygenator (Getinge) and two of both sizes without an oxygenator in series. The circuits were primed with 20 mL of 5% albumin, packed red blood cells, heparin, sodium bicarbonate and calcium gluconate. Circuits were run at 1L/minute continuously. PRV was added to the circuit and levels were obtained pre-and postoxygenator at the following time intervals; 5 mins,1, 2, 3, 4, 5, 6, 8,12, and 24 hrs. PRV was also maintained in a glass vial and samples obtained at the same time periods. The results were consistent in both circuit sizes with no significant PRV loss over the 24-hour study period (<15% loss with oxygenator and <3% loss without oxygenator). This preliminary data suggests PRV dosing may not need to be adjusted for concern of drug loss via the oxygenator. Additional single and multiple dose studies are needed to validate these findings

ABSTRACT/UNASSIGNED:Percutaneous computed tomography-guided transthoracic lung biopsy is an effective and minimally invasive procedure to achieve tissue diagnosis. Radiologists are key in appropriate referral for further workup, with percutaneous computed tomography-guided transthoracic lung biopsy performed by both thoracic and general interventionalists. Percutaneous computed tomography-guided transthoracic lung biopsy is increasingly performed for both diagnostic and research purposes, including molecular analysis. Multiple patient, lesion, and technique-related variables influence diagnostic accuracy and complication rates. A comprehensive understanding of these factors aids in procedure planning and may serve to maximize diagnostic yield while minimizing complications, even in the most challenging scenarios.

OBJECTIVES/OBJECTIVE:To assess the impact of percutaneous dilational tracheostomy in coronavirus disease 2019 patients requiring mechanical ventilation and the risk for healthcare providers. DESIGN/METHODS:Prospective cohort study; patients were enrolled between March 11, and April 29, 2020. The date of final follow-up was July 30, 2020. We used a propensity score matching approach to compare outcomes. Study outcomes were formulated before data collection and analysis. SETTING/METHODS:Critical care units at two large metropolitan hospitals in New York City. PATIENTS/METHODS:Five-hundred forty-one patients with confirmed severe coronavirus disease 2019 respiratory failure requiring mechanical ventilation. INTERVENTIONS/METHODS:Bedside percutaneous dilational tracheostomy with modified visualization and ventilation. MEASUREMENTS AND MAIN RESULTS/RESULTS:Required time for discontinuation off mechanical ventilation, total length of hospitalization, and overall patient survival. Of the 541 patients, 394 patients were eligible for a tracheostomy. One-hundred sixteen were early percutaneous dilational tracheostomies with median time of 9 days after initiation of mechanical ventilation (interquartile range, 7-12 d), whereas 89 were late percutaneous dilational tracheostomies with a median time of 19 days after initiation of mechanical ventilation (interquartile range, 16-24 d). Compared with patients with no tracheostomy, patients with an early percutaneous dilational tracheostomy had a higher probability of discontinuation from mechanical ventilation (absolute difference, 30%; p < 0.001; hazard ratio for successful discontinuation, 2.8; 95% CI, 1.34-5.84; p = 0.006) and a lower mortality (absolute difference, 34%, p < 0.001; hazard ratio for death, 0.11; 95% CI, 0.06-0.22; p < 0.001). Compared with patients with late percutaneous dilational tracheostomy, patients with early percutaneous dilational tracheostomy had higher discontinuation rates from mechanical ventilation (absolute difference 7%; p < 0.35; hazard ratio for successful discontinuation, 1.53; 95% CI, 1.01-2.3; p = 0.04) and had a shorter median duration of mechanical ventilation in survivors (absolute difference, -15 d; p < 0.001). None of the healthcare providers who performed all the percutaneous dilational tracheostomies procedures had clinical symptoms or any positive laboratory test for severe acute respiratory syndrome coronavirus 2 infection. CONCLUSIONS:In coronavirus disease 2019 patients on mechanical ventilation, an early modified percutaneous dilational tracheostomy was safe for patients and healthcare providers and associated with improved clinical outcomes.

Pulmonary nodules are the most common incidental finding in the chest, particularly on computed tomographs that include a portion or all of the chest, and may be encountered more frequently with increasing utilization of cross-sectional imaging. Established guidelines address the reporting and management of incidental pulmonary nodules, both solid and subsolid, synthesizing nodule and patient features to distinguish benign nodules from those of potential clinical consequence. Standard nodule assessment is essential for the accurate reporting of nodule size, attenuation, and morphology, all features with varying risk implications and thus management recommendations.

Lung transplant is increasingly performed for the treatment of end-stage lung disease. As the number of lung transplants and transplant centers continues to rise, radiologists will more frequently participate in the care of patients undergoing lung transplant, both before and after transplant. Potential donors and recipients undergo chest radiography and CT as part of their pretransplant assessment to evaluate for contraindications to transplant and to aid in surgical planning. After transplant, recipients undergo imaging during the postoperative hospitalization and also in the long-term outpatient setting. Radiologists encounter a wide variety of conditions leading to end-stage lung disease and a myriad of posttransplant complications, some of which are unique to lung transplantation. Familiarity with these pathologic conditions, including their imaging findings and their temporal relationship to the transplant, is crucial to accurate radiologic interpretation. Knowledge of the surgical techniques and expected postoperative appearance prevents confusing normal posttransplant imaging findings with complications. A basic understanding of the indications, contraindications, and surgical considerations of lung transplant aids in imaging interpretation and protocoling and also facilitates communication between radiologists and transplant physicians. Despite medical and surgical advances over the past several decades, lung transplant recipients currently have an average posttransplant life expectancy of only 6.7 years. As members of the transplant team, radiologists can help maximize patient survival and hopefully increase posttransplant life expectancy and quality of life in the coming decades. ^©RSNA, 2021 An invited commentary by Bierhals is available online. Online supplemental material is available for this article.