Search

Purpose: Our aim is to assess the potential of an MR system with ultrahigh performance gradients (200 mT/m maximum gradient strength) to address two interrelated challenges in cardiac DTI: low SNR and sensitivity to bulk motion., Methods: Imaging was performed in 20 healthy volunteers, two patients, and one swine post-myocardial infarction. The impact of maximum gradient strength was assessed with spin echo cardiac DTI featuring second-order motion compensation and varying maximum system gradient strengths (40, 80, 200 mT/m). Motion compensation requirements at 200 mT/m were assessed with sequences featuring zeroth-, first-, and second-order motion compensation. SNR, mean diffusivity, fractional anisotropy, helix angle transmurality, and secondary eigenvector angle in the left ventricle were compared., Results: Increasing maximum system gradient strength from 40 and 80 mT/m to 200 mT/m increased SNR of b = 500 s/mm 2 images by 150% and 40% due to reductions in TE. Observed improvements in DTI metrics included reduction in variance in mean diffusivity and helix angle transmurality across healthy volunteers, improved visualization of myocardial borders and delineation of suspected scar. Whereas second-order motion compensation acquisitions were robust to motion-induced signal dropout, zeroth- and first-order motion compensation acquisitions suffered from severe signal loss and localized signal voids, respectively., Conclusion: Ultrahigh performance gradients (200 mT/m) enable high SNR DWIs of the heart and resultant improvements in diffusion tensor metrics. Despite reduced diffusion-encoding duration, second-order motion compensation is required to overcome sensitivity to cardiac motion., (© 2024 The Author(s). Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)

Competing Interests: Conflict of interest: None declared.

Optimizing MRI aortic flow quantification is crucial for accurate assessment of valvular disease severity. In this study, we sought to evaluate the accuracy of a novel method of contouring systolic aortic forward flow in comparison to standard contouring methods at various aortic levels. The study included a cohort of patients with native aortic valve (AoV) disease and a small control group referred to cardiac MRI over a 1-year period. Inclusion criteria included aortic flow quantification at aortic valve and one additional level, and no or trace mitral regurgitation (MR) documented both by the MRI AND an echocardiogram done within a year. In addition to flow quantification with standard contouring (SC), a novel Selective Systolic Contouring (SSC) method was performed at aortic valve level, contouring the area demarcated by the AoV leaflets in systole. The bias in each technique's estimate of aortic forward flow was calculated as the mean difference between aortic forward flow and left ventricular stroke volume (LV SV). 98 patients (mean age 56, 71% male) were included: 33 with tricuspid and 65 with congenitally abnormal (bicuspid or unicuspid) AoV. All methods tended to underestimate aortic forward flow, but the bias was smallest with the SSC method (p < 0.001). Therefore, SSC yielded the lowest estimates of mitral regurgitant volume (4.8 ml) and regurgitant fraction (3.9%) (p < 0.05). SSC at AoV level better approximates LV SV in our cohort, and may provide more accurate quantitative assessment of both aortic and mitral valve function., (© 2024. The Author(s).)

This document discusses preprocedural planning for transcatheter aortic valve replacement, evaluating the imaging modalities used in initial imaging for preprocedure planning under two variants 1) Preintervention planning for transcatheter aortic valve replacement: assessment of aortic root; and 2) Preintervention planning for transcatheter aortic valve replacement: assessment of supravalvular aorta and vascular access. US echocardiography transesophageal, MRI heart function and morphology without and with IV contrast, MRI heart function and morphology without IV contrast and CT heart function and morphology with IV contrast are usually appropriate for assessment of aortic root. CTA chest with IV contrast, CTA abdomen and pelvis with IV contrast, CTA chest abdomen pelvis with IV contrast are usually appropriate for assessment of supravalvular aorta and vascular access. 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., (Copyright © 2023 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Pediatric heart disease is a large and diverse field with an overall prevalence estimated at 6 to 13 per 1,000 live births. This document discusses appropriateness of advanced imaging for a broad range of variants. Diseases covered include tetralogy of Fallot, transposition of great arteries, congenital or acquired pediatric coronary artery abnormality, single ventricle, aortopathy, anomalous pulmonary venous return, aortopathy and aortic coarctation, with indications for advanced imaging spanning the entire natural history of the disease in children and adults, including initial diagnosis, treatment planning, treatment monitoring, and early detection of complications. 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., (Copyright © 2023 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Aim: The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes)., Methods: A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate., Structure: Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease., (Copyright © 2022 American College of Cardiology Foundation and the American Heart Association, Inc. Published by Elsevier Inc. All rights reserved.)

Pulmonary embolism (PE) remains a common and important clinical condition that cannot be accurately diagnosed on the basis of signs, symptoms, and history alone. The diagnosis of PE has been facilitated by technical advancements and multidetector CT pulmonary angiography, which is the major diagnostic modality currently used. Ventilation and perfusion scans remain largely accurate and useful in certain settings. MR angiography can be useful in some clinical scenarios and lower-extremity ultrasound can substitute by demonstrating deep vein thrombosis; however, if negative, further studies to exclude PE are indicated. In all cases, correlation with the clinical status, particularly with risk factors, improves not only the accuracy of diagnostic imaging but also overall utilization. Other diagnostic tests have limited roles. 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., (Copyright © 2022 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Cardiac magnetic resonance imaging plays a central role among multimodality imaging modalities in the assessment, diagnosis, and surveillance of pericardial diseases. Clinicians and imagers should have a foundational understanding of the utilities, advantages, and limitations of cardiac magnetic resonance imaging and how they integrate with other diagnostic tools involved in the evaluation and management of pericardial diseases. This review aims to outline the contemporary magnetic resonance imaging sequences used to evaluate the pericardium, followed by exploring the main clinical applications of magnetic resonance imaging for identifying pericardial inflammation, constriction, and effusion.

Dyspnea is the symptom of perceived breathing discomfort and is commonly encountered in a variety of clinical settings. Cardiac etiologies of dyspnea are an important consideration; among these, valvular heart disease (Variant 1), arrhythmia (Variant 2), and pericardial disease (Variant 3) are reviewed in this document. Imaging plays an important role in the clinical assessment of these suspected abnormalities, with usually appropriate procedures including resting transthoracic echocardiography in all three variants, radiography for Variants 1 and 3, MRI heart function and morphology in Variants 2 and 3, and CT heart function and morphology with intravenous contrast for Variant 3. 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., (Copyright © 2022 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Objective: To compare the diagnostic accuracy of transesophageal echocardiography (TEE) and cardiac computed tomography (CCT) in diagnosing infective endocarditis (IE)., Background: TEE is a mainstay imaging modality for IE, while the use of CCT is becoming increasingly prevalent. Data directly comparing the diagnostic performance of these two imaging modalities for IE are limited., Methods: We conducted a systematic review and meta-analysis of published literature in Embase, PubMed and Cochrane databases through October 1, 2020 for studies comparing diagnostic performance of CCT and TEE for the diagnosis of IE in the same patient populations. A meta-analysis of diagnostic accuracy was performed using the bivariate model based on studies that used surgical pathology as a reference standard for defining endocarditis. From a total of 10 studies included in the meta-analysis, a total of 872 patients were evaluated., Results: The pooled sensitivities and specificities of TEE for detecting vegetations were 96% and 83% respectively, whereas for CCT, they were 85% and 84%, respectively. In the prosthetic valve sub-group, the pooled sensitivities and specificities of TEE for detecting vegetations were 89% and 74% respectively, whereas for CCT, they were 78% and 94%, with CCT being more specific than TEE (p < 0.05). The pooled sensitivities and specificities of TEE for detecting periannular complications were 70% and 96% respectively, whereas for CCT, they were 88% and 93%, respectively. CCT showed a trend (p = 0.06) towards higher sensitivity than TEE for detection of periannular complications. The pooled sensitivities and specificities of TEE for detecting leaflet perforation were 79% and 93% respectively, whereas for CCT, they were 48% and 93% respectively, with TEE being more sensitive (p < 0.05). The two modalities also showed comparable diagnostic performance for detecting fistulae, paravalvular leaks and prosthetic valve dehiscence., Conclusion: In a contemporary comparative meta-analysis, TEE and CCT demonstrated both good diagnostic accuracy for detecting valvular involvement and complications of IE. TEE performed better for detecting leaflet defects, whereas CCT performed better in cases of prosthetic valve involvement, and showed a trend towards improved detection of periannular complications. Appropriate, complementary use of both TEE and CCT in a multimodality imaging approach in clinical practice may achieve the highest diagnostic performance., Competing Interests: Declaration of competing interest All authors declare that they have no relevant conflicts of interest to disclose., (Copyright © 2020 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Nonischemic cardiomyopathies encompass a broad spectrum of myocardial disorders with mechanical or electrical dysfunction without evidence of ischemia. There are five broad variants of nonischemic cardiomyopathies; hypertrophic cardiomyopathy (Variant 1), restrictive or infiltrative cardiomyopathy (Variant 2), dilated or unclassified cardiomyopathy (Variant 3), arrhythmogenic cardiomyopathy (Variant 4), and inflammatory cardiomyopathy (Variant 5). For variants 1, 3, and 4, resting transthoracic echocardiography, MRI heart function and morphology without and with contrast, and MRI heart function and morphology without contrast are the usually appropriate imaging modalities. For variants 2 and 5, resting transthoracic echocardiography and MRI heart function and morphology without and with contrast are the usually appropriate imaging modalities. 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., (Copyright © 2021 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Infective endocarditis (IE) can present with variable clinical and imaging findings and is associated with high morbidity and mortality. Substantial improvement of CT technology, most notably improved temporal and spatial resolution, has resulted in increased use of this modality in the evaluation of IE. The aim of this article is to review the potential role of cardiac CT in evaluating IE. Supplemental material is available for this article. © RSNA, 2021., Competing Interests: Disclosures of Conflicts of Interest: M.B.S. disclosed no relevant relationships. T.K.M.W. Activities related to the present article: disclosed no relevant relationships. Activities not related to the present article: institution received grant from National Heart Foundation of New Zealand (overseas clinical and research fellowship grant). Other relationships: disclosed no relevant relationships. P.C. disclosed no relevant relationships. A.R.W. disclosed no relevant relationships. R.P.J.B. disclosed no relevant relationships. S.U. disclosed no relevant relationships. G.B.P. disclosed no relevant relationships. M.A.B. disclosed no relevant relationships., (2021 by the Radiological Society of North America, Inc.)

Background: Cardiac computed tomography (CT) is emerging as an adjunctive modality to echocardiography in the evaluation of infective endocarditis (IE) and surgical planning. CT studies in IE have, however, focused on its diagnostic rather than prognostic utility, the latter of which is important in high-risk diseases like IE. We evaluated the associations between cardiac CT and transesophageal echocardiography (TEE) findings and adverse outcomes after IE surgery., Methods: Of 833 consecutive patients with surgically proven IE during May 1, 2014 to May 1, 2019, at Cleveland Clinic, 155 underwent both preoperative ECG-gated contrast-enhanced CT and TEE. Multivariable analyses were performed to identify CT and TEE biomarkers that predict adverse outcomes after IE surgery, adjusting for EuroSCORE II (European System for Cardiac operative Risk Evaluation II)., Results: CT and TEE were positive for IE in 123 (75.0%) and 124 (75.6%) of patients, respectively. Thirty-day mortality occurred in 3 (1.9%) patients and composite mortality or morbidities in 72 (46.5%). Pseudoaneurysm or abscess detected on TEE was the only imaging biomarker to show independent association with composite mortality or morbidities in-hospital, with odds ratio (95% CI) of 3.66 (1.76-7.59), P =0.001. There were 17 late deaths, and both pseudoaneurysm or abscess detected on CT and fistula detected on CT were the only independent predictors of total mortality during follow-up, with hazards ratios (95% CI) of 3.82 (1.25-11.7), P <0.001 and 9.84 (1.89-51.0), P =0.007, respectively., Conclusions: We identified cardiac CT and TEE features that predicted separate adverse outcomes after IE surgery. Imaging biomarkers can play important roles incremental to conventional clinical factors for risk stratification in patients undergoing IE surgery.

Chest pain is a frequent cause for emergency department visits and inpatient evaluation, with particular concern for acute coronary syndrome as an etiology, since cardiovascular disease is the leading cause of death in the United States. Although history-based, electrocardiographic, and laboratory evaluations have shown promise in identifying coronary artery disease, early accurate diagnosis is paramount and there is an important role for imaging examinations to determine the presence and extent of anatomic coronary abnormality and ischemic physiology, to guide management with regard to optimal medical therapy or revascularization, and ultimately to thereby improve patient outcomes. A summary of the various methods for initial imaging evaluation of suspected acute coronary syndrome is outlined in this document. 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., (Copyright © 2020 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Background: Imaging plays a key role in the workup of patients with clinically suspected fibromuscular dysplasia (FMD), and research has highlighted the potential of computed tomography angiography (CTA) in screening for thoracic, abdominal, and pelvic arterial abnormalities in these patients. We sought to evaluate imaging findings from patients with suspected or diagnosed FMD who underwent screening CTA at our institution with a novel single-acquisition protocol that offers increased anatomic coverage, with images obtained from the skull vertex to the pelvis., Methods: Images from 80 consecutive patients scanned with the novel single-session CTA protocol covering the skull vertex to the pelvis were compared with images from 20 additional consecutive patients who underwent CTA for the head and neck separate from CTA of the chest, abdomen, and pelvis., Results: Compared with CTA performed in separate sessions, the single-session CTA protocol decreased the radiation dose by 38% (P<0.001) and decreased the contrast dose by 39% (P<0.001), with satisfactory image quality noted in all instances. Additionally, higher mean contrast attenuation was noted in the aortic arch with use of the novel protocol (409±76 HU) versus with use of the dual-acquisition protocol (260±38 HU; P<0.001)., Conclusions: These results suggest that use of a novel single-session CTA protocol extending from the skull vertex to the pelvis provides effective screening imaging in patients with suspected or diagnosed FMD as compared with multisession, standard-pitch CTA., Competing Interests: Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/cdt.2020.02.06). The authors have no conflicts of interest to declare., (2020 Cardiovascular Diagnosis and Therapy. All rights reserved.)

Objectives: This study sought to retrospectively investigate outcomes of lead extraction by using pre-operative computed tomography (CT) scans to identify risk of complicated lead extraction to aid in pre-procedural planning., Background: Transvenous lead extractions remain high-risk procedures requiring specialized operators, equipment, and surgical backup. Data are lacking for how to identify difficult lead extractions. CT scans, which can illustrate the proximity of the lead to adherent venous structures can potentially aid in identifying difficult lead extractions., Methods: All cases of patients who were undergoing transvenous lead extractions at the authors' institution between 2015 and 2018, who had a pre-operative CT scan prior to lead extraction, were reviewed. The images were retrospectively reviewed to examine adherence of leads to the surrounding vein and obtained procedural outcomes., Results: A total of 203 cases were reviewed of patients undergoing transvenous lead extraction who had a pre-operative CT scan, and scans were separated based on lead location in the superior vena cava, as assessed by CT imaging. Scans were divided into 3 groups: those in a central location or <1 cm adherence (n = 28); those that had at least 1 lead with tip adherent >1 cm (n = 137); or those that had at least 1 lead outside the vein contour (n = 38). Although there was only 1 serious complication requiring vascular surgery intervention, patients with at least 1 lead outside the vein contour required significantly longer procedural time (190.8 ± 86.6 min vs. 158.1 ± 73.7 min vs. 142.8 ± 52.2 min; p = 0.019) and fluoroscopy time (33.1 ± 24.2 min vs. 19.6 ± 18.4 min vs. 18.3 ± 16.4 min; p = 0.0006) than those with leads adhering >1 cm and centrally located leads, respectively., Conclusions: Pre-operative CT scanning can identify difficult lead extractions prior to performing the procedure. This information may aid electrophysiologists in the planning of extraction procedures. Future prospective studies are needed to confirm these findings., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: Recurrences of pericarditis (RP) are often difficult to diagnose due to lack of clinical signs and symptoms during subsequent episodes. We aimed to investigate the value of quantitative assessment of pericardial delayed hyperenhancement (DHE) in diagnosing ongoing recurrences of pericarditis., Methods: Quantitative DHE was measured in 200 patients with established diagnosis of RP using cardiac MRI. Conventional clinical criteria for diagnosis of pericarditis were ≥2 of the following: chest pain, pericardial rub, ECG changes and new or worsening pericardial effusion., Results: A total of 67 (34%) patients were identified as having ongoing episode of recurrence at the time of DHE measurements. In multivariable analysis, chest pain (OR: 10.9, p<0.001) and higher DHE (OR: 1.32, p<0.001) were associated with ongoing recurrence of RP. Addition of DHE to conventional clinical criteria significantly increased the ability to diagnose ongoing recurrence (net reclassification improvement (NRI): 0.80, p<0.001; integrated discrimination improvement (IDI): 0.12, p<0.001). Among 150 patients with history of RP who presented with chest pain, higher DHE was still independently associated with ongoing recurrence (OR: 1.28, p<0.001), showed incremental value over clinical criteria (NRI: 0.76, p<0.001; IDI: 0.13, p<0.001) and demonstrated a sensitivity of 70% and specificity of 74%., Conclusion: Among patients with RP, quantitative DHE provided incremental information to diagnose ongoing recurrences over conventional clinical criteria of pericarditis. Quantitative DHE demonstrated acceptable test characteristics to diagnose ongoing recurrence even in RP patients presenting with chest pain., Competing Interests: Competing interests: None declared.

Chronic chest pain (CCP) of a cardiac etiology is a common clinical problem. The diagnosis and classification of the case of chest pain has rapidly evolved providing the clinician with multiple cardiac imaging strategies. Though scintigraphy and rest echocardiography remain as appropriate imaging tools in the diagnostic evaluation, new technology is available. Current evidence supports the use of alternative imaging tests such as coronary computed tomography angiography (CCTA), cardiac MRI (CMRI), or Rb-82 PET/CT. Since multiple imaging modalities are available to the clinician, the most appropriate noninvasive imaging strategy will be based upon the patient's clinical presentation and clinical status. 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., (Copyright © 2018 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

There is a need to review the multimodality imaging techniques, as well as the emerging role of the newer noninvasive imaging modalities in the field of constrictive pericarditis (CP). Therefore, the aim of this review is to summarize the current available techniques that are useful for the diagnosis and differentiation of CP from restrictive cardiomyopathy. Also, we provide illustrative images and videos of typical CP noninvasive imaging findings, as well as a diagnostic and management algorithm. CP is a challenging diagnosis; therefore, cardiologists need adequate knowledge about the application of multimodality noninvasive imaging in a systematic and guideline-oriented fashion whenever CP is suspected.

While there is no single diagnostic test for heart failure (HF), imaging plays a supportive role beginning with confirmation of HF, especially by detecting ventricular dysfunction (Variant 1). Ejection fraction (EF) is important in HF classification, and imaging plays a subsequent role in differentiation between HF with reduced EF (HFrEF) versus preserved EF (HFpEF) (Variant 2). Once HFrEF is identified, distinction between ischemic and nonischemic etiologies with imaging support (Variant 3) facilitates further planning. Imaging approaches which are usually appropriate include: both resting transthoracic echocardiography (TTE) and chest radiography for Variant 1; resting TTE and/or MRI (including functional, without absolute need for contrast) for Variant 2; and for Variant 3, a. Coronary CTA or coronary arteriography (if high pretest probability/symptoms for ischemic disease) for coronary assessment; b. Rest/vasodilator stress SPECT/CT, PET/CT, or MRI for myocardial perfusion assessment; c. Rest/exercise or inotropic stress TTE for myocardial contraction assessment; or d. MRI (including morphologic with contrast) for myocardial characterization. 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., (Copyright © 2018 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

The aim of this brief report is to determine the safety and reliability of minimally invasive video-assisted thoracic surgery (VATS) resection without the aid of intraoperative fluoroscopy after computed tomography (CT)-guided microcoil localization of small peripheral pulmonary nodules. Twenty patients with peripheral lung nodules underwent percutaneous needle localization with a microcoil that was tagged back to the visceral pleural surface. Same-day VATS resection was performed without the use of intraoperative fluoroscopy. All 20 nodules were successfully localized in the CT procedure room, and all 20 nodules were resected with negative margins and no major complications., (Copyright © 2018 SIR. Published by Elsevier Inc. All rights reserved.)

Background: The purpose of this study was to compare the qualitative and quantitative assessment of perfusion on dual-energy CT (DECT) and planar and single photon emission computed tomography (SPECT)-CT V/Q scanning in patients with chronic thromboembolic pulmonary hypertension (CTEPH)., Methods: Nineteen patients with known CTEPH underwent both DECT and SPECT-CT V/Q scanning. Sixteen of these patients underwent planar V/Q imaging concurrently. Two readers independently graded DECT-perfused blood volume (PBV) defects on a four-point scale (0= normal, 1= mild <25%, 2= moderate 25-50%, 3= severe >50%). A grade was given for each lung lobe and for each of 18 lung segments. One reader graded the SPECT-CT images similarly. Quantitative measurements of lung perfusion were calculated with DECT and planar V/Q scanning for 16 of these patients., Results: The inter-reader agreement on DECT was strong with agreement in 85% (258/304) of segments (kappa =0.86) and 84% (80/95) of lobes (kappa =0.82). The inter-modality agreement between DECT and SPECT-CT was lower. Readers 1 and 3 agreed in only 34% (103/304) of segments (kappa =0.25) and 33% (31/94) of lobes (kappa =0.22). Agreement between readers 2 and 3 was similar. Correlation between quantitative measurements with DECT and planar V/Q imaging was poor and ranged from 0.01 to 0.45., Conclusions: Inter-observer agreement in subjective grading of PBV maps is excellent. However, inter-modality agreement between DECT and SPECT-CT is modest. Automated quantification values of PBV maps correlate poorly with established tools like planar V/Q imaging. These differences need to be kept in mind during clinical decision making., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.

Background: Significant improvement of computed tomography (CT) technology in the last decade has led to more use of this modality for evaluating infective endocarditis (IE) especially since the introduction of high resolution electrocardiogram (ECG) synchronized multiphasic (4D) acquisition. While there are a number of reports on the accuracy and value of 4D CT for evaluation of IE, there is no published data regarding the performance of single-phase ECG gated CT for assessment of IE. The purpose of this study is to evaluate the sensitivity and specificity of preoperative single-phase ECG-gated CT imaging versus transesophageal echocardiography (TEE) in the assessment of complications related to IE, with comparison to surgical findings., Methods: Among 899 patients with surgically proven IE in our database, 122 underwent contrast-enhanced ECG cardiac CT and were included in the study; 84 of these patients also underwent TEE., Results: Overall, there was no significant difference between CT and TEE in the identification of pseudoaneurysm/abscess and dehiscence. For the detection of pseudoaneurysm/abscess in prosthetic valves, CT demonstrated higher sensitivity (81% vs. 64%) and specificity (75% vs. 33%) in patients with mechanical aortic valves; TEE demonstrated marginally higher sensitivity (72% vs. 63%) and specificity (80% vs. 73%) in patients with bioprosthetic aortic valves, although the differences are not statistically significant. TEE demonstrated significantly higher sensitivity (85% vs. 16%) in identifying vegetation in all patients (P<0.0001), including patients with prosthetic valves (sensitivity, 78% vs. 19%). The combined imaging findings of CT and TEE demonstrated improved sensitivity in identifying pseudoaneurysm/abscess and slightly improved detection of prosthesis dehiscence., Conclusions: Preoperative single-phase gated CT can be seen as complementary to TEE in assessing complications of suspected IE or may be substituted for TEE when vegetation or dehiscence is depicted on transthoracic echocardiography and the patient has a contraindication to TEE., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.

Purpose To compare the diagnostic yield and complication rates of electromagnetic navigational bronchoscopic (ENB)-guided and computed tomography (CT)-guided percutaneous tissue sampling of lung nodules. Materials and Methods Retrospectively identified were 149 patients sampled percutaneously with CT guidance and 146 patients who underwent ENB with transbronchial biopsy of a lung lesion between 2013 and 2015. Clinical data, incidence of complications, and nodule pathologic analyses were assessed through electronic medical record review. Lung nodule characteristics were reviewed through direct image analysis. Molecular marker studies and pathologic analyses from surgical excision were reviewed when available. Multiple-variable logistic regression models were built to compare the diagnostic yield and complication rates for each method and for different patient and disease characteristics. Results CT-guided sampling was more likely to be diagnostic than ENB-guided biopsy (86.0% [129 of 150] vs 66.0% [99 of 150], respectively), and this difference remained significant even after adjustments were made for patient and nodule characteristics (P < .001). Age, American Society of Anesthesiologists class, emphysema grade, nodule size, and distance from pleura were not significant predictors of increased diagnostic yield. Intraprocedural time for physicians was significantly lower with CT-guided sampling (P < .001). Similar yield for molecular analyses was noted with the two approaches (ENB-guided sampling, 88.9% [32 of 36]; CT-guided sampling, 82.0% [41 of 50]). The two groups had similar rates of major complications (symptomatic hemorrhage, P > .999; pneumothorax requiring chest tube and/or admission, P = .417). Conclusion CT-guided transthoracic biopsy provided higher diagnostic yield in the assessment of peripheral pulmonary nodules than navigational bronchoscopy with a similar rate of clinically relevant complications. © RSNA, 2017 Online supplemental material is available for this article.

Aortic stenosis is a common valvular condition with increasing prevalence in aging populations. When severe and symptomatic, the downstream prognosis is poor without surgical or transcatheter aortic valve replacement. Transcatheter aortic valve replacement is now considered a viable alternative to surgical aortic valve replacement in patients considered high and intermediate risk for surgery. Pre-intervention imaging with echocardiography and CT are essential for procedure planning and device selection to help optimize clinical outcomes with MR angiography playing largely a complementary role. Modern 3-D cross-sectional imaging has consistently shown to help reduce procedural complications from vascular access injury to paravalvular regurgitation and coronary obstruction. 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., (Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Objectives: This study sought to evaluate the diagnostic yield of a dedicated computed tomography angiography (CTA) protocol of the chest, abdomen, and pelvis in patients with fibromuscular dysplasia (FMD)., Background: FMD is an uncommon vascular disease that may result in stenosis, dissection, or aneurysm of nearly all arterial distributions, typically affecting medium-sized arteries. Findings from the United States Registry for Fibromuscular Dysplasia have suggested the potential need to perform screening imaging of the aorta and medium branch vessels., Methods: A total of 113 consecutive patients enrolled in our institutional FMD registry who received a tailored CTA protocol at our institution between March 2013 and June 2015 were included in this study. Arterial phase contrast-enhanced images were obtained on a dual-source scanner using high pitch and electrocardiogram trigger. Images were analyzed by 2 readers., Results: Abnormalities including beading, aneurysm, dissection, and stenosis/occlusion were noted in aortic, renal, mesenteric, and iliac distributions. The most commonly affected vessels were the renal arteries (n = 76 [67%]), followed by the lower extremity/iliac arteries (n = 37 [32%]). Aortic abnormalities were less frequently encountered (n = 3 [3%]), including 1 case with mild dilation (4.2 cm) of the ascending aorta and 2 cases of dissection involving the descending aorta, 1 with mild dilation (4.4 cm). Incremental findings beyond those known at patient intake were commonly noted, including new areas of arterial beading (n = 55 [49%]), new aneurysms (n = 21 [19%]), and new dissections (n = 3 [3%]). Reformatted images were crucial, affecting final assessment in 56% of cases evaluated by reader 1 and 36% evaluated by reader 2., Conclusions: Screening chest, abdomen, and pelvis CTA in patients with FMD showed substantial and incremental diagnostic yield. Reformatted images should routinely be included in imaging analysis. Abnormalities in the aorta were not common, so screening of the thoracic aorta may not be indicated., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Interventional pulmonology (IP) is a relatively new field that uses endoscopy and other technologies for both the diagnosis and treatment of pulmonary and thoracic conditions. IP is a continually developing field driven by clinical need as well as technological and therapeutic innovation. Developments in IP have increased both the efficacy and breadth of procedures that may be encountered by radiologists on periprocedural and postprocedural imaging. In this article, we will describe commonly performed IP procedures, with a focus on relevant imaging implications for radiologists., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Introduction: Although positron emission tomography PET-MR imaging is emerging into clinical practice, many aspects of this imaging technique such as attenuation correction have yet to be validated for myocardial imaging. Thus, it is uncertain whether PET-MR FDG images provide clinical information which is comparable to PET-CT FDG images. The study goal was to systematically compare relative myocardial FDG concentrations obtained from cardiac PET-MR images to those derived from same day PET-CT images., Methods: Myocardial FDG images of 27 patients undergoing PET-CT imaging, followed by PET-MR imaging 42 ± 13 minutes later as part of a prospective oncology study were analyzed. Mean segmental standardized uptake measurements (SUVmean) were obtained in each of the 17 standard myocardial segments and normalized to the brightest segment., Results: Normalized segmental SUVmean values did not differ significantly between the PET-MR and PET-CT images (mean difference 0.002, P = .826). The specific segment was a marginally significant predictor of the differences (P = .057), with the largest difference in the anteroseptal basal segment., Conclusions: PET-MR, vis-à-vis PET-CT, does not significantly raise segmental uptake relative to the brightest segment, suggesting that PET-MR can be used similarly to PET-CT for applications where relative uptake is important.

Valvular heart disease is a group of complex entities with varying etiologies and clinical presentations. There are a number of imaging tools available to supplement clinical evaluation of suspected valvular heart disease, with echocardiography being the most common and clinically established, and more recent emergence of computed tomography and magnetic resonance imaging as additional supportive techniques. Yet even with these newer and more sophisticated modalities, chest radiography remains one of the earliest and most common diagnostic examinations performed during the triage of patients with suspected cardiac dysfunction. Recognizing the anatomic and pathologic features of cardiac radiography including the heart's adaptation to varying hemodynamic changes can provide clues to the radiologist regarding the underlying etiology. In this article, we will elucidate several principles relating to chamber modifications in response to pressure and volume overload as well as radiographic appearances associated with pulmonary fluid status and cardiac dysfunction. We will also present a pattern approach to optimize analysis of the chest radiograph for valvular heart disease, which will help guide the radiologist down a differential diagnostic pathway and create a more meaningful clinical report.

To assess the utility of cardiac magnetic resonance (MR) imaging in the diagnosis of constrictive pericarditis (CP). This study was approved by the institutional review board, with a waiver of informed consent. A total of 42 consecutive patients (mean age, 55 ± 16 years; 3 women, 39 men) with CP treated with pericardiectomy who had undergone cardiac MR before surgery were evaluated retrospectively. An additional 21 patients were evaluated as a control group; of these, 10 consecutive patients received cardiac MR for reasons other than suspected pericardial disease, and 11 consecutive patients had a history of pericarditis but no clinical suspicion of pericardial constriction. MR imaging parameters were analyzed independently and with a decision tree algorithm for usefulness in the prediction of CP. Catheterization data were also reviewed when available. A model combining pericardial thickness and relative interventricular septal (IVS) excursion provided the best overall performance in prediction of CP (C statistic, 0.98, 100% sensitivity, 90% specificity). Several individual parameters also showed strong predictive value in the assessment of constriction, including relative IVS excursion (sensitivity, 93%; specificity, 95%), pericardial thickness (sensitivity, 83%; specificity, 100%), qualitative assessment of pathologic coupling (sensitivity, 88%; specificity, 100%), diastolic IVS bounce (sensitivity, 90%; specificity, 85%), left ventricle area change (sensitivity, 86%; specificity, 100%), and eccentricity index (sensitivity, 86%; specificity, 90%; all P < 0.001). Strong agreement was observed between catheterization and surgical findings of constriction (97%). Cardiac MR provides robust quantitative and qualitative analysis for the diagnosis of CP.

Heart failure is recognized with increasing frequency worldwide and often progresses to an advanced refractory state. Although the reference standard for treatment of advanced heart failure remains cardiac transplantation, the increasing shortage of donor organs and the unsuitability of many patients for transplantation surgery has led to a search for alternative therapies. One such therapy is mechanical circulatory support, which helps relieve the load on the ventricle and thereby allows it to recover function. In addition, there is increasing evidence supporting the use of mechanical devices as a bridge to recovery in patients with acute refractory heart failure. In this article, the imaging evaluation of various commonly used short- and long-term cardiac assist devices is discussed, and their relevant mechanisms of action and physiology are described. Imaging, particularly computed tomography (CT), plays a crucial role in preoperative evaluation for assessment of candidacy for implantation of a left ventricular assist device (LVAD) or total artificial heart (TAH). Also, echocardiography and CT are indispensable in assessment of complications associated with cardiac devices. Complications commonly associated with short-term assist devices include bleeding and malpositioning, whereas long-term devices such as LVADs may be associated with infection, pump thrombosis, and cannula malfunction, as well as bleeding. CT is also commonly performed for preoperative planning before LVAD or TAH explantation, replacement of a device or one of its components, and cardiac transplantation. Online supplemental material is available for this article., ((©)RSNA, 2015.)

Background: Preprocedural 3-dimensional CT imaging of the aortic annular plane plays a critical role for transcatheter aortic valve replacement (TAVR) planning; however, manual reconstructions are complex. Automated analysis software may improve reproducibility and agreement between readers but is incompletely validated., Methods: In 110 TAVR patients (mean age, 81 years; 37% female) undergoing preprocedural multidetector CT, automated reconstruction of the aortic annular plane and planimetry of the annulus was performed with a prototype of now commercially available software (syngo.CT Cardiac Function-Valve Pilot; Siemens Healthcare, Erlangen, Germany). Fully automated, semiautomated, and manual annulus measurements were compared. Intrareader and inter-reader agreement, intermodality agreement, and interchangeability were analyzed. Finally, the impact of these measurements on recommended valve size was evaluated., Results: Semiautomated analysis required major correction in 5 patients (4.5%). In the remaining 95.5%, only minor correction was performed. Mean manual annulus area was significantly smaller than fully automated results (P < .001 for both readers) but similar to semiautomated measurements (5.0 vs 5.4 vs 4.9 cm(2), respectively). The frequency of concordant recommendations for valve size increased if manual analysis was replaced with the semiautomated method (60% agreement was improved to 82.4%; 95% confidence interval for the difference [69.1%-83.4%])., Conclusions: Semiautomated aortic annulus analysis, with minor correction by the user, provides reliable results in the context of TAVR annulus evaluation., (Copyright © 2015 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.)

Objectives: We investigated the effects of lung transplantation on right ventricular (RV) function as well as the prognostic value of pre- and post-transplantation RV function., Background: Although lung transplantation success has improved over recent decades, outcomes remain a challenge. Identifying predictors of mortality in lung transplant recipients may lead to improved long-term outcomes after lung transplantation., Methods: Eighty-nine (age 60 ± 6 years, 58 men) consecutive patients who underwent single or double lung transplantation and had pre- and post-transplantation echocardiograms between July 2001 and August 2012 were evaluated. Echocardiographic measurements were performed before and after lung transplantation. Left ventricular (LV) and RV longitudinal strains were analyzed using velocity vector imaging. Cox proportional prognostic hazard models predicting all-cause death were built., Results: There were 46 all-cause (52%) and 17 cardiac (19%) deaths during 43 ± 33 months of follow-up. After lung transplantation, echocardiography showed improved systolic pulmonary artery pressure (SPAP) (50 ± 19 mm Hg to 40 ± 13 mm Hg) and RV strain (-17 ± 5% to -18 ± 4%). No pre-transplantation RV parameter predicted all-cause mortality. After adjustment for age, sex, surgery type, and etiology of lung disease in a Cox proportional hazards model, both post-transplantation RV strain (hazard ratio: 1.13, 95% confidence interval: 1.04 to 1.23, p = 0.005), and post-transplantation SPAP (hazard ratio: 1.03, 95% confidence interval: 1.01 to 1.05, p = 0.011) were independent predictors of all-cause mortality. When post-transplantation RV strain and post-transplantation SPAP were added the clinical predictive model based on age, sex, surgery type, and etiology, the C-statistic improves from 0.60 to 0.80 (p = 0.002)., Conclusions: Alterations of RV function and pulmonary artery pressure normalize, and post-transplantation RV function may provide prognostic data in patients after lung transplantation. Our study is based on a highly and retrospectively selected group. We believe that larger prospective studies are warranted to confirm this result., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objective: Transcatheter aortic valve implantation has emerged as a viable treatment alternative for patients with severe aortic stenosis who are not surgical candidates. Multidimensional (3D and 4D) MDCT angiography plays a critical role in the safety, success, and outcome of an institutional transcatheter aortic valve implantation program., Conclusion: Given the increasing therapeutic role of this innovative technique, an understanding of essential imaging concepts in its context is critical for appropriate image acquisition and interpretation.

Although 3-T magnetic resonance (MR) imaging is well established in neuroradiology and musculoskeletal imaging, it is in the nascent stages in cardiovascular imaging applications, and there is limited literature on this topic. The primary advantage of 3 T over 1.5 T is a higher signal-to-noise ratio (SNR), which can be used as such or traded off to improve spatial or temporal resolution and decrease acquisition time. However, the actual gain in SNR is limited by other factors and modifications in sequences adapted for use at 3 T. Higher resonance frequencies result in improved spectral resolution, which is beneficial for fat suppression and spectroscopy. The higher T1 values of tissues at 3 T aid in myocardial tagging, angiography, and perfusion and delayed-enhancement sequences. However, there are substantial challenges with 3-T cardiac MR imaging, including higher magnetic field and radiofrequency inhomogeneities and susceptibility effects, which diminish image quality. Off-resonance artifacts are particularly challenging, especially with steady-state free precession sequences. These artifacts can be managed by using higher-order shimming, frequency scouts, or low repetition times. B1 inhomogeneities can be managed by using radiofrequency shimming, multitransmit coils, or adiabatic pulses. Chemical shifts are also increased at 3 T. The higher radiofrequency results in higher radiofrequency deposition power and a higher specific absorption rate. MR angiography, dynamic first-pass perfusion sequences, myocardial tagging, and MR spectroscopy are more effective at 3 T, whereas delayed-enhancement, flow quantification, and black-blood sequences are comparable at 1.5 T and 3 T. Knowledge of the relevant physics helps in identifying artifacts and modifying sequences to optimize image quality. Online supplemental material is available for this article.

Objective: The purpose of this study was to compare high-pitch ECG-synchronized pulmonary CT angiography (CTA) with standard pulmonary CTA with regard to radiation dose and image quality in patients with suspected pulmonary embolism., Subjects and Methods: This prospective study was approved by the institutional review board, and participants provided informed consent. Patients with suspected pulmonary embolism (60% women; mean age, 57 ± 14 years) were randomized to undergo high-pitch ECG-synchronized pulmonary CTA (n = 26) or standard pulmonary CTA (n = 21). Two independent readers assessed subjective image quality of pulmonary arteries, cardiovascular structures, and pulmonary parenchyma. Signal intensity (SI) was measured in one segmental and three central pulmonary arteries., Results: High-pitch ECG-synchronized pulmonary CTA showed higher SI (p < 0.001) for pulmonary arteries. Image quality scores indicated improvement in assessment of cardio-vascular structures (p < 0.001), minimization of motion of central (p < 0.001) pulmonary arteries, and an increase in pulmonary arterial enhancement (p = 0.01) with high-pitch ECG-synchronized pulmonary CTA. Image quality scores for lung assessment were higher for standard pulmonary CTA (p < 0.001). The amount of contrast agent administered was similar between techniques (p = 0.86). Radiation dose was lower for high-pitch ECG-synchronized pulmonary CTA (p < 0.001)., Conclusion: High-pitch ECG-synchronized pulmonary CTA provides higher pulmonary arterial SI, decreased motion of central pulmonary arteries, and improved assessment of cardiovascular structures with similar contrast dose and lower radiation compared with standard pulmonary CTA.

Background: The aim of our study was to compare myocardial mechanics of constrictive pericarditis (CP) with restrictive cardiomyopathy (RCM), or healthy controls; to assess the impact of pericardial thickening detected by cardiac magnetic resonance on regional myocardial mechanics in CP; and to quantitate the effect of pericardiectomy on myocardial mechanics in CP., Methods and Results: Myocardial mechanics were evaluated by 2-dimensional speckle tracking in 52 consecutive patients with CP who underwent cardiac magnetic resonance examination before pericardiectomy, 35 patients with RCM, and 26 control subjects. CP patients had selectively depressed left ventricular (LV) anterolateral wall strain (LWS) and right ventricular (RV) free wall longitudinal systolic strain (FWS) but preserved LV septal wall systolic strain (SWS). In a comparison of RCM and normals, CP patients had significantly lower regional longitudinal systolic strain ratios (CP versus RCM and normal; LVLWS/LVSWS: 0.8±0.2 versus 1.1±0.2 and 1.0±0.2; P<0.001, RVFWS/LVSWS: 0.8±0.4 vs. 1.4±0.5 and 1.2±0.2; P<0.001). LVLWS/LVSWS was more robust than the LV lateral wall to LV septal wall ratio of early diastolic velocities at the LV base (LE'/SE') in differentiating CP from RCM (area under the curve=0.91 versus 0.76; P=0.011). There was a significant inverse correlation between pericardial thickness and respective ventricular strains (P=0.001). Pericardiectomy resulted in the improvement of the depressed LVLWS/LVSWS (0.83±0.18-0.95±0.12; P<0.001)., Conclusions: Regional longitudinal systolic strain ratios are robust novel diagnostic tools for CP. Regional myocardial mechanics inversely correlates with adjacent pericardial segment thickness detected by cardiac magnetic resonance, and pericardiectomy leads to systolic strain improvement, which is more pronounced in right ventricular and LV free walls.

Flow assessment with phase contrast magnetic resonance imaging (PC-MRI) protocols is an important component of a comprehensive cardiovascular MR (CMR) assessment. Breath-hold (BH) and non-breath-hold (NBH) PC-MRI protocols are widely available for this imaging modality. Because flow in the great vessels is known to vary with the respiratory cycle, we hypothesized that these 2 approaches might yield different results in the clinical assessment of forward and regurgitant flow in the ascending aorta. Further, given renewed awareness of the possible effect of velocity offsets in PC-MRI, we also sought to evaluate the impact of BH and NBH protocols on this potential source of error. A prospective observational study was performed in 55 consecutive patients referred for clinical CMR of the thoracic aorta. Both BH and NBH protocols were performed at the sinotubular junction and at the mid ascending aorta. Ten additional patients underwent repeated scanning at the mid ascending aorta with both BH and NBH protocols so that protocol variability could be assessed. Finally, ten patients were scanned with both BH and NBH protocols, and phantoms were then imaged with identical imaging parameters so that offset errors associated with each protocol could be evaluated. Forward flow was generally greater with the NBH protocol than with the BH protocol (mean values 102.1 mL vs. 97.9 mL; P = 0.0004). The Bland-Altman limits of agreement were quite wide for all indices (e.g, forward flow, -26.7 mL, +18.2 mL), which suggests that results from BH and NBH protocols cannot be interchanged with confidence. Estimated phase offset errors were similar for both protocols and were generally within acceptable ranges at the mid ascending level, with slightly higher values observed at the sinotubular junction for the BH technique. We observed differences in flow values with BH and NBH protocols for PC-MRI. This finding is relevant to patients imaged serially for the evaluation of cardiac output or valve (aortic or mitral) insufficiency, for whom adherence to one PC-MRI breathing protocol is likely most effective.