Training and Verification Requirements for Interpretation of Cardiac CT and MRI: AJR Expert Panel Narrative Review.

The use of cardiac CT and MRI is rapidly expanding based on strong evidence from large international trials. The number of physicians competent to interpret cardiac CT and MRI may be unable to keep pace with the increasing demand. Societies and organizations have prescribed training requirements for interpreting cardiac CT and MRI, with recent updates focusing on the increased breadth of competency that is now required due to ongoing imaging advances. In this AJR Expert Panel Narrative Review, we discuss several aspects of cardiac CT and MRI training, focusing on topics that are uncertain or not addressed in existing society statements and guidelines, including determination of competency in different practice types in real-world settings and the impact of artificial intelligence on training and education. The article is intended to guide updates in professional society training requirements and also inform institutional verification processes.

Utility of CT and MRI in Cardiac Electrophysiology.

Cardiac electrophysiology involves the diagnosis and management of arrhythmias. CT and MRI play an increasingly important role in cardiac electrophysiology, primarily in preprocedural planning of ablation procedures but also in procedural guidance and postprocedural follow-up. The most common applications include ablation for atrial fibrillation (AF), ablation for ventricular tachycardia (VT), and for planning cardiac resynchronization therapy (CRT). For AF ablation, preprocedural evaluation includes anatomic evaluation and planning using CT or MRI as well as evaluation for left atrial fibrosis using MRI, a marker of poor outcomes following ablation. Procedural guidance during AF ablation is achieved by fusing anatomic data from CT or MRI with electroanatomic mapping to guide the procedure. Postprocedural imaging with CT following AF ablation is commonly used to evaluate for complications such as pulmonary vein stenosis and atrioesophageal fistula. For VT ablation, both MRI and CT are used to identify scar, representing the arrhythmogenic substrate targeted for ablation, and to plan the optimal approach for ablation. CT or MR images may be fused with electroanatomic maps for intraprocedural guidance during VT ablation and may also be used to assess for complications following ablation. Finally, functional information from MRI may be used to identify patients who may benefit from CRT, and cardiac vein mapping with CT or MRI may assist in planning access. ©RSNA, 2024 Supplemental material is available for this article.

Incidence of cryoballoon expansion dislodgement during pulmonary vein isolation-An underappreciated frequent cause of incomplete isolation.

BACKGROUND: Cryoballoon ablation for atrial fibrillation (AF) requires adequate contact between the pulmonary vein (PV) antrum and cryoballoon. The surge of intraballoon pressure during the initial phase of ablation may change the balloon's shape and compliance, resulting in balloon dislodgement and loss of PV occlusion. Without continuous monitoring, this phenomenon is often undetected but can be associated with incomplete PV isolation (PVI). METHODS: Primary cryoablation of AF was performed in 15 patients. PV occlusion status pre- and post-freezing were analyzed with intracardiac echocardiography (ICE) and dielectric imaging-based occlusion tool (DIOT) to calculate the incidence of expansion dislodgement of cryoballoon. RESULTS: A total of 105 cryoablation applications were performed on 57 veins, including three common ostiums of left pulmonary veins. In the evaluation of PV occlusion, both modalities reported consistent results in 86.7% of the assessments. Despite complete PV occlusion before ablation, peri-balloon leak after initiation of freezing was detected by ICE in 5/22 (22.7%) applications and by DIOT in 8/25 (32%) applications. CONCLUSION: Incidence of expansion dislodgement of the cryoballoon was detected in one-fourth to one-third of cryoablation applications depending on the imaging modality used, which was clinically frequent and significant.

Antithrombotic Therapy and Hematoma Risk during Image-guided Core-Needle Breast Biopsy.

Background For image-guided core-needle breast biopsy (CNBB), it remains unclear whether antithrombotic medication should be withheld because of hematoma risk. Purpose To determine hematoma risk after CNBB in patients receiving antithrombotic medication and to stratify risk by antithrombotic type. Materials and Methods This HIPAA-compliant retrospective study included US-, stereotactic-, or MRI-guided CNBBs performed across six academic and six private practices between April 2019 and April 2021. Patients were instructed to continue antithrombotic medications, forming two groups: antithrombotic and nonantithrombotic. Hematomas were defined as new biopsy-site masses with a diameter of 2 cm or larger on postprocedure mammograms. Hematomas were considered clinically significant if management involved an intervention other than manual compression. Patient age, type of antithrombotic medication, practice type, image guidance modality, needle gauge and type, and outcome of pathologic analysis were recorded. Multivariable logistic regression analysis was used to analyze variables associated with hematomas. Results A total of 3311 biopsies were performed in 2664 patients (median age, 60 years; IQR, 48-70 years; 2658 women). The nonantithrombotic group included 2788 biopsies, and the antithrombotic group included 523 biopsies (328 low-dose aspirin, 73 full-dose antiplatelet drugs, 51 direct oral anticoagulants, 36 warfarin, 32 daily nonsteroidal anti-inflammatory drugs, three heparin or enoxaparin). The antithrombotic group had a higher overall hematoma rate (antithrombotic group: 49 of 523 biopsies [9.4%], nonantithrombotic group: 172 of 2788 biopsies [6.2%]; P = .007), but clinically significant hematoma rates were not different (antithrombotic group: two of 523 biopsies [0.4%], nonantithrombotic group: one of 2788 biopsies [0.04%]; P = .07). At multivariable analysis, age (odds ratio [OR], 1.02; 95% CI: 1.01, 1.03; P < .001), 9-gauge or larger needles (OR, 2.1; 95% CI: 1.28, 3.3; P = .003), and full-dose antiplatelet drugs (OR, 2.5; 95% CI: 1.29, 5.0; P = .007) were associated with higher hematoma rates. US guidance (OR, 0.26; 95% CI: 0.17, 0.40; P < .001) and 10-14-gauge needles (OR, 0.53; 95% CI: 0.36, 0.79; P = .002) were predictive of no hematoma. Conclusion Because clinically significant hematomas were uncommon, withholding antithrombotic medications before core-needle breast biopsy may be unnecessary. Postbiopsy hematomas were associated with full-dose antiplatelet drugs, patient age, and 9-gauge or larger needles. No association was found with other types of antithrombotic medication. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Chang and Yoen in this issue.

Role of advanced imaging with cardiac computed tomography and MRI in atrial and ventricular ablation.

PURPOSE OF REVIEW: Increasing evidence supports the use of advanced imaging with cardiac computed tomography (CCT) and cardiac magnetic resonance (CMR) in the work-up of patients with arrythmias being considered for ablation. RECENT FINDINGS: Advances in imaging technology and postprocessing are facilitating the use of advanced imaging before, during and after ablation in patients with both atrial and ventricular arrhythmias.In atrial arrythmias, quantitative assessment of left atrial wall thickness on CCT and quantification of late gadolinium enhancement (LGE) on CMR identify patients more likely to develop recurrent atrial arrythmias following ablation. In addition, in patients with recurrent arrythmia post ablation, LGE CMR can potentially identify targets for repeat ablation.In ventricular arrythmias, qualitative assessment of LGE can aide in determining the optimal ablation approach and predicts likelihood of ventricular arrythmias inducibility. Quantitative assessment of LGE can identify conduction channels that can be targeted for ablation. On CCT, quantitative assessment of left ventricular wall thickness can demonstrate myocardial ridges associated with re-entrant circuits for ablation. SUMMARY: This review focuses on the utility of CCT and CMR in identifying key anatomical components and arrhythmogenic substrate contributing to both atrial and ventricular arrhythmias in patients being considered for ablation. Advanced imaging has the potential to improve procedural outcomes, decrease complications and shorten procedural time.

Lessons learned from a delayed diagnosis of atrioesophageal fistula: A multidisciplinary approach.

Atrioesophageal fistulas are a rare complication of radiofrequency ablation (RFA) that requires rapid identification and emergent surgical repair to prevent morbidity and mortality. We report a case of a 32-year-old man with atrial fibrillation presenting with chest pain followed by rapidly progressive sepsis and embolic cerebrovascular accident 23 days after RFA. Subtle initially overlooked findings on multiple computed tomography caused a delay in diagnosis. Atrioesophageal fistulas remain diagnostically challenging. A high index of suspicion coupled with serial computed tomography of the chest with intravenous and oral contrast reviewed by a multimodal team is essential to make a timely diagnosis.

Altered pulmonary blood volume distribution as a biomarker for predicting outcomes in COVID-19 disease.

INTRODUCTION: Evidence suggests that vascular inflammation and thrombosis may be important drivers of poor clinical outcomes in patients with COVID-19. We hypothesised that a significant decrease in the percentage of blood volume in vessels with a cross-sectional area between 1.25 and 5 mm2 relative to the total pulmonary blood volume (BV5%) on chest computed tomography (CT) in COVID-19 patients is predictive of adverse clinical outcomes. METHODS: We performed a retrospective analysis of chest CT scans from 10 hospitals across two US states in 313 COVID-19-positive and 195 COVID-19-negative patients seeking acute medical care. RESULTS: BV5% was predictive of outcomes in COVID-19 patients in a multivariate model, with a BV5% threshold below 25% associated with OR 5.58 for mortality, OR 3.20 for intubation and OR 2.54 for the composite of mortality or intubation. A model using age and BV5% had an area under the receiver operating characteristic curve of 0.85 to predict the composite of mortality or intubation in COVID-19 patients. BV5% was not predictive of clinical outcomes in patients without COVID-19. CONCLUSIONS: The data suggest BV5% as a novel biomarker for predicting adverse outcomes in patients with COVID-19 seeking acute medical care.

Chromatographic evidence of silyl ether formation (SEF) in supercritical fluid chromatography.

In this article, we propose that silyl ether formation (SEF) is a major contribution to retention and selectivity variation over time for supercritical fluid chromatography (SFC). In the past, the variations were attributed to instrumentation, but high performance SFC systems have shed new light on the source of variation. As silyl ethers form on the particle surface, the hydrophilicity is decreased, significantly altering the retention and selectivity observed. SEF is expected to occur with any chromatographic particle containing silanols but is slowed on hybrid inorganic/organic particles. The SEF reaction is between alcohols on the particle surface and in the mobile phase solvent. We have found that storage conditions of a column are paramount, which can either prevent or accelerate the process. Because SEF exists as an equilibrium between the liquid phase and the particle surface, the process is also reversible. The silanols can be hydroxylated (regenerated) to their original state upon exposure to water. The next generation of stationary phases will either advantageously utilize SEF or effectively mitigate its effects. Mitigation of SEF would be a significant improvement in SFC that has the potential to vault their performance to levels of similar reproducibility and reliability observed for high performance liquid chromatography (HPLC). Further research in SEF may lead to a better understanding of the mechanism of interaction between the solutes and chromatographic surface.

MRI in Patients with Cardiovascular Implantable Electronic Devices and Fractured or Abandoned Leads.

Purpose To examine the clinical effect of lead length and lead orientation in patients with cardiac implantable electronic devices (CIEDs) and lead fragments or abandoned leads undergoing 1.5-T MRI. Materials and Methods This Health Insurance Portability and Accountability Act-compliant retrospective study included patients with CIEDs and abandoned leads or lead fragments undergoing 1.5-T MRI from March 2014 through July 2020. CIED settings before and after MRI were reviewed, with clinically significant variations defined as a composite of the change in capture threshold of at least 50%, in sensing of at least 40%, or in lead impedance of at least 30% between before MRI and after MRI interrogation. Adverse clinical events were assessed at MRI and up to 30 days after. Univariable and multivariable analysis was performed. Results Eighty patients with 126 abandoned CIED leads or lead fragments underwent 107 1.5-T MRI examinations. Sixty-seven patients (median age, 74 years; IQR, 66-78 years; 44 male patients, 23 female patients) had abandoned leads, and 13 (median age, 66 years; IQR, 52-74 years; nine male patients, four female patients) had lead fragments. There were no reported deaths, clinically significant arrhythmias, or adverse clinical events within 30 days of MRI. Three patients with abandoned leads had a significant change in the composite of capture threshold, sensing, or lead impedance. In a multivariable generalized estimating equation analysis, lead orientation, lead length, MRI type, and MRI duration were not associated with a significant change in the composite outcome. Conclusion Use of 1.5-T MRI in patients with abandoned CIED leads or lead fragments of varying length and orientation was not associated with adverse clinical events. Keywords: Cardiac Assist Devices, MRI, Cardiac Implantable Electronic Device Supplemental material is available for this article. © RSNA, 2024.

ACR Appropriateness Criteria® Workup of Pleural Effusion or Pleural Disease.

Pleural effusions are categorized as transudative or exudative, with transudative effusions usually reflecting the sequala of a systemic etiology and exudative effusions usually resulting from a process localized to the pleura. Common causes of transudative pleural effusions include congestive heart failure, cirrhosis, and renal failure, whereas exudative effusions are typically due to infection, malignancy, or autoimmune disorders. This document summarizes appropriateness guidelines for imaging in four common clinical scenarios in patients with known or suspected pleural effusion or pleural disease. 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 process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Aortic annulus measurement and relevance to successful transcatheter aortic valve replacement: a new technique using 3D TEE.

BACKGROUND: There are limitations of using 2D imaging to accurately size the aortic annulus. This article highlights the limitations of 2D technology and proposes a new 3D TEE method for sizing of the aortic annulus. METHODS: Three-dimensional echocardiography with the method described can identify the "true" aortic annulus with precision. A 3D dataset of the aortic annulus is collected. The 3D quantification program is then activated. The three multiplanar reconstruction planes (the aortic short-axis, long-axis, and coronal planes) are aligned during systole, to obtain the 3 nadirs of the sinuses of Valsalva simultaneously in the short-axis MPR. Rotating the sagittal and coronal planes to identify the hinge points is necessary to measure the diameter of the "true" annulus. The "true" aortic annulus is defined by the blood-tissue interface in the aortic short-axis MPR. RESULTS: This method has been prospectively validated with surgical AVR sizing in a small study of 10 patients. During surgical AVR, the annulus was directly measured using a sizer. This served as a gold standard for comparison. The annulus was measured using the method described in a blinded fashion by the cardiac anesthesiologist and then confirmed offline by a blinded echocardiographer. In this small study, the Pearson correlation coefficient was 0.9833 with 23.4 and 23.22 mm being the mean measurements with the 2 methods. DISCUSSION: The method described in this article is complementary to multidetector computed tomography and provides a real-time measurement of the annulus during the TAVR procedure without need for radiographic contrast.

Does the presence of mediastinal adenopathy confer a risk for disseminated infection in immunocompetent persons with pulmonary coccidioidomycosis?

Pulmonary coccidioidomycosis is caused by inhaling airborne arthroconidia of Coccidioides, a soil-dwelling fungus endemic to the desert southwestern United States. Although uncommon, disseminated coccidioidal infection can be associated with well-defined risk factors, such as cell-mediated immunodeficiency, certain racial heritages (e.g. African or Filipino), male sex, or pregnancy. Before widespread use of computed tomography (CT), the presence or persistence of mediastinal lymphadenopathy was postulated to be a risk factor for disseminated coccidioidal infection. To investigate the use of CT scanning to identify the presence of mediastinal lymphadenopathy in patients with pulmonary coccidioidomycosis, and to correlate such lymphadenopathy with disseminated coccidioidal infection, we performed a retrospective review of patients with pulmonary coccidioidomycosis who were evaluated by chest CT. Two radiologists independently interpreted 150 CT scans from patients with pulmonary coccidioidomycosis. Forty-nine patients met CT criteria for mediastinal lymphadenopathy, whereas 101 patients did not. Disseminated coccidioidal infection was observed in 5 (10%) of the 49 patients with mediastinal lymphadenopathy and in 6 of the 101 (6%; P = .34) without such adenopathy. Among patients with coccidioidomycosis, patients with mediastinal lymphadenopathy, as assessed by CT, had a higher rate of disseminated infection, but the difference was not statistically significant.

Invasive Lobular Carcinoma: A Review of Imaging Modalities with Special Focus on Pathology Concordance.

Invasive lobular cancer (ILC) is the second most common type of breast cancer. It is characterized by a unique growth pattern making it difficult to detect on conventional breast imaging. ILC can be multicentric, multifocal, and bilateral, with a high likelihood of incomplete excision after breast-conserving surgery. We reviewed the conventional as well as newly emerging imaging modalities for detecting and determining the extent of ILC- and compared the main advantages of MRI vs. contrast-enhanced mammogram (CEM). Our review of the literature finds that MRI and CEM clearly surpass conventional breast imaging in terms of sensitivity, specificity, ipsilateral and contralateral cancer detection, concordance, and estimation of tumor size for ILC. Both MRI and CEM have each been shown to enhance surgical outcomes in patients with newly diagnosed ILC that had one of these imaging modalities added to their preoperative workup.

ACR Appropriateness Criteria® Incidentally Detected Indeterminate Pulmonary Nodule.

Incidental pulmonary nodules are common. Although the majority are benign, most are indeterminate for malignancy when first encountered making their management challenging. CT remains the primary imaging modality to first characterize and follow-up incidental lung nodules. This document reviews available literature on various imaging modalities and summarizes management of indeterminate pulmonary nodules detected incidentally. 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 process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Lung Cancer Screening: 2022 Update.

Lung cancer remains the leading cause of cancer-related mortality for men and women in the United States. Screening for lung cancer with annual low-dose CT is saving lives, and the continued implementation of lung screening can save many more. In 2015, the CMS began covering annual lung screening for those who qualified based on the original United States Preventive Services Task Force (USPSTF) lung screening criteria, which included patients 55 to 77 year of age with a 30 pack-year history of smoking, who were either currently using tobacco or who had smoked within the previous 15 years. In 2021, the USPSTF issued new screening guidelines, decreasing the age of eligibility to 80 years of age and pack-years to 20. Lung screening remains controversial for those who do not meet the updated USPSTF criteria, but who have additional risk factors for the development of lung cancer. 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 process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

CT findings and long-term mortality after pulmonary embolism.

OBJECTIVE: The utility of CT findings in predicting long-term mortality in patients with acute pulmonary embolism (PE) is unknown. The purpose of this study is to retrospectively determine whether three CT findings--increased embolic burden, interventricular septal bowing toward the left ventricle, and right ventricle-to-left ventricle (RV/LV) diameter ratio greater than 1--are independent predictors of long-term all-cause mortality after acute PE. MATERIALS AND METHODS: A total of 1105 patients (47% female; mean age, 63 ± 16 years) with CT scans positive for PE from January 1, 1997, to December 31, 2002, were included. Scans were independently interpreted by two observers, with a third independent observer reviewing discrepant cases. CT findings and clinical information were compared with all-cause mortality using univariate and multivariate logistic regression analyses. RESULTS: The median duration of survival was 6.2 years following acute PE, with estimated 10-year survival of 37.4%. CT-derived embolic burden was associated with a very small decrease in long-term all-cause mortality in both univariate (hazard ratio [HR], 0.97; p < 0.001) and multivariate (HR, 0.97; p < 0.001) analyses. Interventricular septal bowing and RV/LV diameter ratio were not significantly associated with long-term all-cause mortality. CONCLUSION: CT findings are not predictive of decreased long-term survival after acute PE.

ACR Appropriateness Criteria® Suspected Pulmonary Hypertension: 2022 Update.

Pulmonary hypertension may be idiopathic or related to a large variety of diseases. Various imaging examinations may be helpful in diagnosing and determining the etiology of pulmonary hypertension. Imaging examinations discussed in this document include chest radiography, ultrasound echocardiography, ventilation/perfusion scintigraphy, CT, MRI, right heart catheterization, and pulmonary angiography. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.