ACR Appropriateness Criteria® Chronic Chest Pain-High Probability of Coronary Artery Disease: 2021 Update.

Management of patients with chronic chest pain in the setting of high probability of coronary artery disease (CAD) relies heavily on imaging for determining or excluding presence and severity of myocardial ischemia, hibernation, scarring, and/or the presence, site, and severity of obstructive coronary lesions, as well as course of management and long-term prognosis. In patients with no known ischemic heart disease, imaging is valuable in determining and documenting the presence, extent, and severity of obstructive coronary narrowing and presence of myocardial ischemia. In patients with known ischemic heart disease, imaging findings are important in determining the management of patients with chronic myocardial ischemia and can serve as a decision-making tool for medical therapy, angioplasty, stenting, or surgery. This document summarizes the recent growing body of evidence on various imaging tests and makes recommendations for imaging based on the available data and expert opinion. This document is focused on epicardial CAD and does not discuss the microvascular disease as the cause for CAD. 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.

Preoperative Thoracic CT Findings Associated With Postoperative Mechanical Ventilation in Patients Undergoing Major Abdominal or Pelvic Surgery: A Matched Case-Control Study.

BACKGROUND. Postoperative prolonged mechanical ventilation is associated with increased morbidity and mortality. Reliable predictors of the need for postoperative mechanical ventilation after abdominal or pelvic surgeries are lacking. OBJECTIVE. The purpose of this study was to explore associations between preoperative thoracic CT findings and the need for postoperative mechanical ventilation after major abdominal or pelvic surgeries. METHODS. This retrospective case-control study included patients who underwent abdominal or pelvic surgeries during the period from January 1, 2014, through December 31, 2018, and had undergone preoperative thoracic CT. Case patients were patients who required postoperative mechanical ventilation. Control patients and case patients were matched at a 3:1 ratio on the basis of age, sex, body mass index, chronic obstructive pulmonary disease, smoking status, and surgery type. Two radiologists (readers 1 and 2) reviewed the CT images. Findings were compared between groups. RESULTS. The study included 165 patients (70 women, 95 men; mean age, 67.0 ± 9.7 [SD] years; 42 case patients and 123 matched control patients). Bronchial wall thickening and pericardial effusion were more frequent in case patients than control patients for reader 2 (10% vs 2%, p = .03; 17% vs 5%, p = .01) but not for reader 1. Pulmonary artery diameter (mean ± SD) was greater in case patients than control patients for reader 2 (2.9 ± 0.5 cm vs 2.8 ± 0.5 cm, p = .045) but not reader 1. Right lung height was lower in case patients than control patients for reader 1 (18.4 ± 2.9 cm vs 19.9 ± 2.7 cm, p = .01) and reader 2 (18.3 ± 2.9 cm vs 19.8 ± 2.7 cm, p = .01). Left lung height was lower in case patients than control patients for reader 1 (19.5 ± 3.1 cm vs 21.1 ± 2.6 cm, p = .01) and reader 2 (19.6 ± 2.4 cm vs 20.9 ± 2.6 cm, p = .01). Anteroposterior (AP) chest diameter was greater for case patients than control patients for reader 1 (14.0 ± 2.3 cm vs 12.9 ± 3.7 cm, p = .02) and reader 2 (14.2 ± 2.2 cm vs 13.2 ± 3.6 cm, p = .04). In a multivariable regression model using pooled reader data, bronchial wall thickening exhibited an odds ratio (OR) of 4.6 (95% CI, 1.3-16.5; p = .02); pericardial effusion, an OR of 5.1 (95% CI, 1.7-15.5; p = .004); pulmonary artery diameter, an OR of 1.4 per 1-cm increase (95% CI, 0.7-3.0; p = .32); mean lung height, an OR of 0.8 per 1-cm increase (95% CI, 0.7-1.001; p = .05); and AP chest diameter, an OR of 1.2 per 1-cm increase (95% CI, 1.013-1.4; p = .03). CONCLUSION. CT features are associated with the need for postoperative mechanical ventilation after abdominal or pelvic surgery. CLINICAL IMPACT. Many patients undergo thoracic CT before abdominal or pelvic surgery; the CT findings may complement preoperative clinical risk factors.

International Consensus Statement on Nomenclature and Classification of the Congenital Bicuspid Aortic Valve and Its Aortopathy, for Clinical, Surgical, Interventional and Research Purposes.

This International Consensus Classification and Nomenclature for the congenital bicuspid aortic valve condition recognizes 3 types of bicuspid valves: 1. The fused type (right-left cusp fusion, right-non-coronary cusp fusion and left-non-coronary cusp fusion phenotypes); 2. The 2-sinus type (latero-lateral and antero-posterior phenotypes); and 3. The partial-fusion (forme fruste) type. The presence of raphe and the symmetry of the fused type phenotypes are critical aspects to describe. The International Consensus also recognizes 3 types of bicuspid valve-associated aortopathy: 1. The ascending phenotype; 2. The root phenotype; and 3. Extended phenotypes. © 2021 Jointly between the RSNA, the European Association for Cardio-Thoracic Surgery, The Society of Thoracic Surgeons, and the American Association for Thoracic Surgery. The articles are identical except for minor stylistic and spelling differences in keeping with each journal's style. All rights reserved. Keywords: Bicuspid Aortic Valve, Aortopathy, Nomenclature, Classification.

Summary: international consensus statement on nomenclature and classification of the congenital bicuspid aortic valve and its aortopathy, for clinical, surgical, interventional and research purposes.

This International evidence-based nomenclature and classification consensus on the congenital bicuspid aortic valve and its aortopathy recognizes 3 types of bicuspid aortic valve: 1. Fused type, with 3 phenotypes: right-left cusp fusion, right-non cusp fusion and left-non cusp fusion; 2. 2-sinus type with 2 phenotypes: Latero-lateral and antero-posterior; and 3. Partial-fusion or forme fruste. This consensus recognizes 3 bicuspid-aortopathy types: 1. Ascending phenotype; root phenotype; and 3. extended phenotypes.

International consensus statement on nomenclature and classification of the congenital bicuspid aortic valve and its aortopathy, for clinical, surgical, interventional and research purposes.

This International Consensus Classification and Nomenclature for the congenital bicuspid aortic valve condition recognizes 3 types of bicuspid valves: 1. The fused type (right-left cusp fusion, right-non-coronary cusp fusion and left-non-coronary cusp fusion phenotypes); 2. The 2-sinus type (latero-lateral and antero-posterior phenotypes); and 3. The partial-fusion (forme fruste) type. The presence of raphe and the symmetry of the fused type phenotypes are critical aspects to describe. The International Consensus also recognizes 3 types of bicuspid valve-associated aortopathy: 1. The ascending phenotype; 2. The root phenotype; and 3. Extended phenotypes.

Summary: International Consensus Statement on Nomenclature and Classification of the Congenital Bicuspid Aortic Valve and Its Aortopathy, for Clinical, Surgical, Interventional and Research Purposes.

This International evidence-based nomenclature and classification consensus on the congenital bicuspid aortic valve and its aortopathy recognizes 3 types of bicuspid aortic valve: 1. Fused type, with 3 phenotypes: right-left cusp fusion, right-non cusp fusion and left-non cusp fusion; 2. 2-sinus type with 2 phenotypes: Latero-lateral and antero-posterior; and 3. Partial-fusion or forme fruste. This consensus recognizes 3 bicuspid-aortopathy types: 1. Ascending phenotype; root phenotype; and 3. extended phenotypes.

International Consensus Statement on Nomenclature and Classification of the Congenital Bicuspid Aortic Valve and Its Aortopathy, for Clinical, Surgical, Interventional and Research Purposes.

This International Consensus Classification and Nomenclature for the congenital bicuspid aortic valve condition recognizes 3 types of bicuspid valves: 1. The fused type (right-left cusp fusion, right-non-coronary cusp fusion and left-non-coronary cusp fusion phenotypes); 2. The 2-sinus type (latero-lateral and antero-posterior phenotypes); and 3. The partial-fusion (forme fruste) type. The presence of raphe and the symmetry of the fused type phenotypes are critical aspects to describe. The International Consensus also recognizes 3 types of bicuspid valve-associated aortopathy: 1. The ascending phenotype; 2. The root phenotype; and 3. Extended phenotypes.

Summary: International consensus statement on nomenclature and classification of the congenital bicuspid aortic valve and its aortopathy, for clinical, surgical, interventional, and research purposes.

This International evidence-based nomenclature and classification consensus on the congenital bicuspid aortic valve and its aortopathy recognizes 3 types of bicuspid aortic valve: 1. Fused type, with 3 phenotypes: right-left cusp fusion, right-non cusp fusion and left-non cusp fusion; 2. 2-sinus type with 2 phenotypes: Latero-lateral and antero-posterior; and 3. Partial-fusion or forme fruste. This consensus recognizes 3 bicuspid-aortopathy types: 1. Ascending phenotype; root phenotype; and 3. extended phenotypes.

International consensus statement on nomenclature and classification of the congenital bicuspid aortic valve and its aortopathy, for clinical, surgical, interventional and research purposes.

This International Consensus Classification and Nomenclature for the congenital bicuspid aortic valve condition recognizes 3 types of bicuspid valves: 1. The fused type (right-left cusp fusion, right-non-coronary cusp fusion and left-non-coronary cusp fusion phenotypes); 2. The 2-sinus type (latero-lateral and antero-posterior phenotypes); and 3. The partial-fusion (forme fruste) type. The presence of raphe and the symmetry of the fused type phenotypes are critical aspects to describe. The International Consensus also recognizes 3 types of bicuspid valve-associated aortopathy: 1. The ascending phenotype; 2. The root phenotype; and 3. Extended phenotypes.

Differentiating combined pulmonary fibrosis and emphysema from pure emphysema: utility of late gadolinium-enhanced MRI.

BACKGROUND: Differentiating combined pulmonary fibrosis with emphysema (CPFE) from pure emphysema can be challenging on high-resolution computed tomography (HRCT). This has antifibrotic therapy implications. METHODS: Twenty patients with suspected CPFE underwent late gadolinium-enhanced (LGE) thoracic magnetic resonance imaging (LGE-MRI) and HRCT. Data from twelve healthy control subjects from a previous study who underwent thoracic LGE-MRI were included for comparison. Quantitative LGE signal intensity (SI) was retrospectively compared in regions of fibrosis and emphysema in CPFE patients to similar lung regions in controls. Qualitative comparisons for the presence/extent of reticulation, honeycombing, and traction bronchiectasis between LGE-MRI and HRCT were assessed by two readers in consensus. RESULTS: There were significant quantitative differences in fibrosis SI compared to emphysema SI in CPFE patients (25.8, IQR 18.4-31.0 versus 5.3, IQR 5.0-8.1, p < 0.001). Significant differences were found between LGE-MRI and HRCT in the extent of reticulation (12.5, IQR 5.0-20.0 versus 25.0, IQR 15.0-26.3, p = 0.038) and honeycombing (5.0, IQR 0.0-10.0 versus 20.0, IQR 10.6-20.0, p = 0.001) but not traction bronchiectasis (10.0, IQR 5-15 versus 15.0, IQR 5-15, p = 0.878). Receiver operator curve analysis of fibrosis SI compared to similarly located regions in control subjects showed an area under the curve of 0.82 (p = 0.002). A SI cutoff of 19 yielded a sensitivity of 75% and specificity of 86% in differentiating fibrosis from similarly located regions in control subjects. CONCLUSION: LGE-MRI can differentiate CPFE from pure emphysema and may be a useful adjunct test to HRCT in patients with suspected CPFE.

A Comprehensive CT Radiation Dose Reduction and Protocol Standardization Program in a Complex, Tertiary Hospital System.

PURPOSE: To present our experience in reducing CT radiation doses in a complex tertiary health system through CT protocol standardization and optimization. METHODS: A CT radiation task force was created to reduce CT protocol heterogeneity and radiation doses. Redundant protocols were eliminated. By an iterative process, protocols with least radiation dose were identified. Radiation dose tracking software was used to store and analyze radiation doses. CT protocols were published in an intranet site after training of technologists. SOPs were established for maintaining and changing protocols. The radiation doses for each CT protocol before and after optimization were compared using geometric means. RESULTS: A total of 222 CT protocols were reviewed, with elimination of 86 protocols. One-year follow-up showed homogeneous protocols with lower radiation doses. The improvement in radiation doses ranged from 23% to 58% (P< 0.001). CONCLUSION: CT radiation dose reduction of up to 58% can be achieved by homogenizing and optimizing CT protocols through a comprehensive CT operations program.

Translation of Quantitative Imaging Biomarkers into Clinical Chest CT.

Quantitative imaging has been proposed as the next frontier in radiology as part of an effort to improve patient care through precision medicine. In 2007, the Radiological Society of North America launched the Quantitative Imaging Biomarkers Alliance (QIBA), an initiative aimed at improving the value and practicality of quantitative imaging biomarkers by reducing variability across devices, sites, patients, and time. Chest CT occupies a strategic position in this initiative because it is one of the most frequently used imaging modalities, anatomically encompassing the leading causes of mortality worldwide. To date, QIBA has worked on profiles focused on the accurate, reproducible, and meaningful use of volumetric measurements of lung lesions in chest CT. However, other quantitative methods are on the verge of translation from research grounds into clinical practice, including (a) assessment of parenchymal and airway changes in patients with chronic obstructive pulmonary disease, (b) analysis of perfusion with dual-energy CT biomarkers, and (c) opportunistic screening for coronary atherosclerosis and low bone mass by using chest CT examinations performed for other indications. The rationale for and the key facts related to the application of these quantitative imaging biomarkers in cardiothoracic chest CT are presented. ©RSNA, 2019 See discussion on this article by Buckler (pp 977-980).

Multimodality Imaging of Complications of Cardiac Valve Surgeries.

Replacement with a prosthetic heart valve (PHV) remains the definitive surgical procedure for management of severe cardiac valve disease. PHV dysfunction is uncommon but can be a life-threatening condition. The broad hemodynamic and pathophysiologic manifestations of PHV dysfunction are stenosis, regurgitation, and a stuck leaflet. Specific structural abnormalities that cause PHV dysfunction include prosthetic valve-patient mismatch, structural failure, valve calcification, dehiscence, paravalvular leak, infective endocarditis, abscess, pseudoaneurysm, abnormal connections, thrombus, hypoattenuating leaflet thickening, and pannus. Multiple imaging modalities are available for evaluating a PHV and its dysfunction. Transthoracic echocardiography is often the first-line imaging modality, with additional modalities such as transesophageal echocardiography, CT, MRI, cine fluoroscopy, and nuclear medicine used for further characterization and establishing a specific cause. The authors review PHVs and the role of imaging modalities in evaluation of PHV dysfunction and illustrate the imaging appearances of different complications. Online supplemental material is available for this article. ©RSNA, 2019.

Electronic Cigarette or Vaping-associated Lung Injury (EVALI): The Tip of the Iceberg.

The Centers for Disease Control and Prevention, the U.S. Food and Drug Administration, and state and local health departments have begun an investigation into the lung injury attributed to the use of electronic cigarette (e-cigarette) or vaping products. A clinical case of a 24-year-old man who used e-cigarette products regularly and presented with shortness of breath, productive cough, chest pain, and fever for 1 week was discussed. Radiographic and CT findings in that patient were reviewed. Recent cases of e-cigarette-associated lung injury from the literature were summarized to continue the dialogue and encourage radiologists to research this relatively new and specific type of lung injury. © RSNA, 2019.

Radiation dose reduction for musculoskeletal computed tomography of the pelvis with preserved image quality.

OBJECTIVE: To analyze the impact of pelvic computed tomography (CT) technique optimization on estimated dose and subjective and objective image quality. MATERIALS AND METHODS: An institutional review board (IRB)-approved retrospective records review was performed with waived informed consent. Five CT scanners (various manufacturers/models) were standardized to match the lowest dose profile on campus via subjective assessment of clinical images by experienced musculoskeletal radiologists. The lowest dose profile had previously been established through image assessment by experienced musculoskeletal radiologists after a department-wide radiation dose reduction initiative. A consecutive series of 60 pre- and 59 post-optimization bony pelvis CTs were analyzed by two residents, who obtained signal-to-noise ratio for femoral cortex and marrow, gluteus medius muscle, and subcutaneous and visceral fat in a standardized fashion. Two blinded attending radiologists ranked image quality from poor to excellent. RESULTS: Pre- and post-optimization subjects exhibited no difference in gender, age, or BMI (p > 0.2). Mean CT dose index (CTDIvol) and dose-length product (DLP) decreased by approximately 45%, from 39± 14 to 18± 12 mGy (p < 0.0001) and 1,227± 469 to 546± 384 mGy-cm (p < 0.0001). Lower body mass index (BMI) was associated with a larger dose reduction and higher BMI with higher DLP regardless of pre- or post-optimization examination. Inter-observer agreement was 0.64-0.92 for SNR measurements. Cortex SNR increased significantly for both observers (p < 0.02). Although qualitative image quality significantly decreased for one observer (p < 0.01), adequate mean quality (3.3 out of 5) was maintained for both observers. CONCLUSION: Subjective and objective image quality for pelvic CT examination remains adequate, despite a substantially reduced radiation dose.

Coronary computed tomographic imaging in women: An expert consensus statement from the Society of Cardiovascular Computed Tomography.

This expert consensus statement from the Society of Cardiovascular Computed Tomography (SCCT) provides an evidence synthesis on the use of computed tomography (CT) imaging for diagnosis and risk stratification of coronary artery disease in women. From large patient and population cohorts of asymptomatic women, detection of any coronary artery calcium that identifies females with a 10-year atherosclerotic cardiovascular disease risk of >7.5% may more effectively triage women who may benefit from pharmacologic therapy. In addition to accurate detection of obstructive coronary artery disease (CAD), CT angiography (CTA) identifies nonobstructive atherosclerotic plaque extent and composition which is otherwise not detected by alternative stress testing modalities. Moreover, CTA has superior risk stratification when compared to stress testing in symptomatic women with stable chest pain (or equivalent) symptoms. For the evaluation of symptomatic women both in the emergency department and the outpatient setting, there is abundant evidence from large observational registries and multi-center randomized trials, that CT imaging is an effective procedure. Although radiation doses are far less for CT when compared to nuclear imaging, radiation dose reduction strategies should be applied in all women undergoing CT imaging. Effective and appropriate use of CT imaging can provide the means for improved detection of at-risk women and thereby focus preventive management resulting in long-term risk reduction and improved clinical outcomes.

Pseudoenhancement effects on iodine quantification from dual-energy spectral CT systems: A multi-vendor phantom study regarding renal lesion characterization.

PURPOSE: To measure the effect of pseudoenhancement on spectral CT iodine quantification as a function of lesion size, lesion iodine level, background iodine level, helical versus axial scanning, and spectral CT scanner type in a phantom model. MATERIALS AND METHODS: A custom-built water-filled cylindrical phantom contained either six small vials (8 mm diameter) or six large vials (27 mm diameter) of aqueous iopamidol solutions (0, 0.5, 1.0, 2.0, 4.0 and 6.0 mg iodine/mL). The background iodine concentration was 0, 5, or 10 mg iodine/mL. Helical and axial scans were taken on three different dual-energy spectral CT scanners (two image-based and one projection-based) with the scan parameters consistent between the systems. ROIs were used to measure the average iodine concentration of the vials in the 36 individual scans. Linear fits of the true versus measured iodine values were used for pvalue statistical analysis. Having a y-intercept or slope p-value less than 0.05 implied statistically significant iodine quantification errors. RESULTS: Iodine quantification pseudoenhancement effects are inversely proportional to lesion size and lesion enhancement and are directly proportional to background attenuation level. No significant differences between helical and axial scans were observed. 100% and 88% of the slope and y-intercept p-values were below 0.05 for the two image-based systems, while 13% of the slope and y-intercept p-values were below 0.05 for the projection-based system. CONCLUSIONS: Pseudoenhancement can artificially increase spectral CT iodine quantification levels most notably for small low-enhancing lesions (<5.0 mg iodine/mL) surrounded by a high attenuating background (10 mg iodine/mL). In this study we found iodine quantification to be more accurate on projection-based spectral CT systems than image-based systems.

Dual-layer spectral detector CT: non-inferiority assessment compared to dual-source dual-energy CT in discriminating uric acid from non-uric acid renal stones ex vivo.

PURPOSE: To assess the non-inferiority of dual-layer spectral detector CT (SDCT) compared to dual-source dual-energy CT (dsDECT) in discriminating uric acid (UA) from non-UA stones. METHODS: Fifty-seven extracted urinary calculi were placed in a cylindrical phantom in a water bath and scanned on a SDCT scanner (IQon, Philips Healthcare) and second- and third-generation dsDECT scanners (Somatom Flash and Force, Siemens Healthcare) under matched scan parameters. For SDCT data, conventional images and virtual monoenergetic reconstructions were created. A customized 3D growing region segmentation tool was used to segment each stone on a pixel-by-pixel basis for statistical analysis. Median virtual monoenergetic ratios (VMRs) of 40/200, 62/92, and 62/100 for each stone were recorded. For dsDECT data, dual-energy ratio (DER) for each stone was recorded from vendor-specific postprocessing software (Syngo Via) using the Kidney Stones Application. The clinical reference standard of X-ray diffraction analysis was used to assess non-inferiority. Area under the receiver-operating characteristic curve (AUC) was used to assess diagnostic performance of detecting UA stones. RESULTS: Six pure UA, 47 pure calcium-based, 1 pure cystine, and 3 mixed struvite stones were scanned. All pure UA stones were correctly separated from non-UA stones using SDCT and dsDECT (AUC = 1). For UA stones, median VMR was 0.95-0.99 and DER 1.00-1.02. For non-UA stones, median VMR was 1.4-4.1 and DER 1.39-1.69. CONCLUSION: SDCT spectral reconstructions demonstrate similar performance to those of dsDECT in discriminating UA from non-UA stones in a phantom model.