Ultra-High-Resolution and K-Edge Imaging of Prosthetic Heart Valves With Spectral Photon-Counting CT: A Phantom Study

BACKGROUND AND PURPOSE

The contribution of cardiac computed tomography (CT) for the detection and characterization of prosthetic heart valve (PHV) complications is still limited due mainly to artifacts. Computed tomography systems equipped with photon-counting detectors (PCDs) have the potential to overcome these limitations. Therefore, the aim of the study was to compare image quality of PHV with PCD-CT and dual-energy dual-layer CT (DEDL-CT).

MATERIALS AND METHODS

Two metallic and 3 biological PHVs were placed in a tube containing diluted iodinated contrast inside a thoracic phantom and scanned repeatedly at different angles on a DEDL-CT and PCD-CT. Two small lesions (~2 mm thickness; containing muscle and fat, respectively) were attached to the structure of 4 valves, placed inside the thoracic phantom, with and without an extension ring, and scanned again. Acquisition parameters were matched for the 2 CT systems and used for all scans. Metallic valves were scanned again with parameters adapted for tungsten K-edge imaging. For all valves, different metallic parts were measured on conventional images to assess their thickness and blooming artifacts. In addition, 6 parallelepipeds per metallic valve were drawn, and all voxels with density <3 times the standard deviation of the contrast media were recorded as an estimate of streak artifacts. For subjective analysis, 3 expert readers assessed conventional images of the valves, with and without lesions, and tungsten K-edge images. Conspicuity and sharpness of the different parts of the valve, the lesions, metallic, and blooming artifacts were scored on a 4-point scale. Measurements and scores were compared with the paired t test or Wilcoxon test.

RESULTS

The objective analysis showed that, with PCD-CT, valvular metallic structures were thinner and presented less blooming artifacts. Metallic artifacts were also reduced with PCD-CT (11 [interquartile (IQ) = 6] vs 40 [IQ = 13] % of voxels). Subjective analysis allowed noticing that some structures were visible or clearly visible only with PCD-CT. In addition, PCD-CT yielded better scores for the conspicuity and for the sharpness of all structures (all P s < 0.006), except for the conspicuity of the leaflets of the mechanical valves, which were well visible with either technique (4 [IQ = 3] for both). Both blooming and streak artifacts were reduced with PCD-CT ( P ≤ 0.01). Overall, the use of PCD-CT resulted in better conspicuity and sharpness of the lesions compared with DEDL-CT (both P s < 0.02). In addition, only with PCD-CT some differences between the 2 lesions were detectable. Adding the extension ring resulted in reduced conspicuity and sharpness with DEDL-CT ( P = 0.04 and P = 0.02, respectively) and only in reduced sharpness with PCD-CT ( P = 0.04). Tungsten K-edge imaging allowed for the visualization of the only dense structure containing it, the leaflets, and it resulted in images judged having less blooming and metallic artifacts as compared with conventional PCD-CT images ( P < 0.01).

CONCLUSIONS

With PCD-CT, objective and subjective image quality of metallic and biological PHVs is improved compared with DEDL-CT. Notwithstanding the improvements in image quality, millimetric lesions attached to the structure of the valves remain a challenge for PCD-CT. Tungsten K-edge imaging allows for even further reduction of artifacts.

CT imaging post-TAVI: Murphy's first law in action-preparing to recognize the unexpected

Transfemoral aortic valve implantation (TAVI) has been long considered the standard of therapy for high-risk patients with severe aortic-stenosis and is now effectively employed in place of surgical aortic valve replacement also in intermediate-risk patients. The potential lasting consequences of minor complications, which might have limited impact on elderly patients, could be more noteworthy in the longer term when occurring in younger individuals. That's why a greater focus on early diagnosis, correct management, and prevention of post-procedural complications is key to achieve satisfactory results. ECG-triggered multidetector computed tomography angiography (CTA) is the mainstay imaging modality for pre-procedural planning of TAVI and is also used for post-interventional early detection of both acute and long-term complications. CTA allows detailed morphological analysis of the valve and its movement throughout the entire cardiac cycle. Moreover, stent position, coronary artery branches, and integrity of the aortic root can be precisely evaluated. Imaging reliability implies the correct technical setting of the computed tomography scan, knowledge of valve type, normal post-interventional findings, and awareness of classic and life-threatening complications after a TAVI procedure. This educational review discusses the main post-procedural complications of TAVI with a specific imaging focus, trying to clearly describe the technical aspects of CTA Imaging in post-TAVI and its clinical applications and challenges, with a final focus on future perspectives and emerging technologies. CRITICAL RELEVANCE STATEMENT: This review undertakes an analysis of the role computed tomography angiography (CTA) plays in the assessment of post-TAVI complications. Highlighting the educational issues related to the topic, empowers radiologists to refine their clinical approach, contributing to enhanced patient care. KEY POINTS: Prompt recognition of TAVI complications, ranging from value issues to death, is crucial. Adherence to recommended scanning protocols, and the optimization of tailored protocols, is essential. CTA is central in the diagnosis of TAVI complications and functions as a gatekeeper to treatment.

Guidelines for the Evaluation of Prosthetic Valve Function With Cardiovascular Imaging: A Report From the American Society of Echocardiography Developed in Collaboration With the Society for Cardiovascular Magnetic Resonance and the Society of Cardiovascular Computed Tomography

In patients with significant cardiac valvular disease, intervention with either valve repair or valve replacement may be inevitable. Although valve repair is frequently performed, especially for mitral and tricuspid regurgitation, valve replacement remains common, particularly in adults. Diagnostic methods are often needed to assess the function of the prosthesis. Echocardiography is the first-line method for noninvasive evaluation of prosthetic valve function. The transthoracic approach is complemented with two-dimensional and three-dimensional transesophageal echocardiography for further refinement of valve morphology and function when needed. More recently, advances in computed tomography and cardiac magnetic resonance have enhanced their roles in evaluating valvular heart disease. This document offers a review of the echocardiographic techniques used and provides recommendations and general guidelines for evaluation of prosthetic valve function on the basis of the scientific literature and consensus of a panel of experts. This guideline discusses the role of advanced imaging with transesophageal echocardiography, cardiac computed tomography, and cardiac magnetic resonance in evaluating prosthetic valve structure, function, and regurgitation. It replaces the 2009 American Society of Echocardiography guideline on prosthetic valves and complements the 2019 guideline on the evaluation of valvular regurgitation after percutaneous valve repair or replacement.

Aortic root abscess from Enterococcus faecalis infective endocarditis: Case report and brief review of the literature

Infective endocarditis is a life-threatening disease that is associated with a significant risk of morbidity and mortality. One of the most serious complications of infective endocarditis is perivalvular and aortic root abscess formation. Due to the high propensity for rupture and continued spread within the aorta and surrounding organs, surgical management is recommended and can improve long-term survival. Imaging plays a critical role in diagnosis of infective endocarditis and its sequalae. Initial workup includes transthoracic and/or transesophageal echocardiography, as part of the modified Duke criteria for diagnosing infective endocarditis. If paravalvular abscesses are suspected, CTA chest can characterize invasion and spread of the abscess. Here, we present a 55-year-old male with recurrent infective endocarditis with an aortic root abscess. The abscess was first identified through transesophageal echocardiography and subsequently confirmed using CTA chest. Surgically, the patient required pulmonic and aortic valve replacement along with aortic root reconstruction.

Right Heart Failure as an Atypical Presentation of Chronic Type A Aortic Dissection - Multimodality Imaging for Accurate Diagnosis and Treatment. A case report and mini-review of literature

Background

An intrapericardial organized haematoma secondary to chronic type A aortic dissection is an extremely rare cause of right heart failure. Imaging studies are essential in recognising and diagnosis of this distinctive medical condition and guiding the anticipated treatment.

Case presentation

A 70-year-old male patient was admitted for progressive symptoms of right heart failure. His cardiovascular history exposed an aortic valve replacement 22 years before with a Medtronic Hall 23 tilting valve with no regular follow-up. Classical signs of congestion were recognized at physical examination. Transthoracic two-dimensional echocardiography and thoraco-abdominal computed tomography angiography, as essential parts of multimodality imaging algorithm, established the underlying cause of right heart failure. Under total cardiopulmonary bypass and cardiac arrest, surgical removal of the haematoma and proximal repair of the ascending aorta with a patient-matched vascular graft were successfully performed. The patient was discharged in good condition with appropriate pharmacological treatment, guideline-directed; no imagistic signs of acute post-surgery complications were ascertained.

Conclusion

This paper highlights the importance of recognizing and providing a timely clinical and imagistic diagnosis of this very rare, potentially avoidable cause of right heart failure in patients with previous cardiac surgery.

Large aortic pseudoaneurysm after Bentall procedure in a patient with Marfan's syndrome

An 11-year-old male with Marfan's syndrome and aortic root dilatation underwent an uneventful Bentall procedure to replace his aortic root and valve. Five months later, surveillance echocardiogram revealed a slowly enlarging pseudoaneurysm arising from the ascending aorta. This finding was subsequently confirmed by computed tomographic angiogram. The patient had successful open surgical repair and paraaortic hematoma evacuation.

Multimodality Imaging in the Diagnosis of Prosthetic Valve Endocarditis: A Brief Review

Infective endocarditis is a common and treatable condition that carries a high mortality rate. Currently the workup of infective endocarditis relies on the integration of clinical, microbiological and echocardiographic data through the use of the modified Duke criteria (MDC). However, in cases of prosthetic valve endocarditis (PVE) echocardiography can be normal or non-diagnostic in a high proportion of cases leading to decreased sensitivity for the MDC. Evolving multimodality imaging techniques including leukocyte scintigraphy (white blood cell imaging), 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), multidetector computed tomographic angiography (MDCTA), and cardiac magnetic resonance imaging (CMRI) may each augment the standard workup of PVE and increase diagnostic accuracy. While further studies are necessary to clarify the ideal role for each of these imaging techniques, nevertheless, these modalities hold promise in determining the diagnosis, prognosis, and care of PVE. We start by presenting a clinical vignette, then evidence supporting various modality strategies, balanced by limitations, and review of formal guidelines, when available. The article ends with the authors' summary of future directions and case conclusion.

Best Practices for Imaging Cardiac Device-Related Infections and Endocarditis: A JACC: Cardiovascular Imaging Expert Panel Statement

The diagnosis of cardiac device infection and, more importantly, accurate localization of the infection site, such as defibrillator pocket, pacemaker lead, along the peripheral driveline or central portion of the left ventricular assist device, prosthetic valve ring abscesses, and perivalvular extensions, remain clinically challenging. Although transthoracic and transesophageal echocardiography are the first-line imaging tests in suspected endocarditis and for assessing hemodynamic complications, recent studies suggest that cardiac computed tomography (CT) or CT angiography and functional imaging with ¹⁸F-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) with CT (FDG PET/CT) may have an incremental role in technically limited or inconclusive cases on echocardiography. One of the key benefits of FDG PET/CT is in its detection of inflammatory cells early in the infection process, before morphological damages ensue. However, there are many unanswered questions in the literature. In this document, we provide consensus on best practices among the various imaging studies, which includes the detection of cardiac device infection, differentiation of infection from inflammation, image-guided patient management, and detailed recommendations on patient preparation, image acquisition, processing, interpretation, and standardized reporting.

Pseudoaneurysm of the aortic root following aortic valve endocarditis - a case with 2 rare life - threatening complications

Infective endocarditis can have peri-annular spread and involve the valvular annulus and adjacent cardiac structures, leading to tissue necrosis and peri-annular abscess. This process may cause pseudoaneurysm formation and other rare and potentially life-threatening complications, so their identification and correct diagnosis are crucial.

We describe a case of an 81-year-old woman, with a history of aortic valve replacement and worsening of symptoms, that presents at the imaging a pseudoaneurysm of the aortic root complicated at the same time by 2 life-threatening conditions: fistulization in the Right Ventricular Outflow Tract (RVOT) and the compression of Right Coronary Artery (RCA).

This case underlines the importance of imaging, especially Coronary Computed Tomography Angiography (CCTA), in the diagnosis and follow-up of infective endocarditis and its complications, especially in a patient not eligible for surgery.

Catheter-based Closure of a Post-infective Aortic Paravalvular Pseudoaneurysm Fistula With Severe Regurgitation After Two Valve Replacement Surgeries: A Case Report

Backgsround: Infective endocarditis (IE) of prosthetic valves is a dire complication of cardiac valve replacement surgery and is associated with high rates of morbidity and mortality. Case Summary: A 72-year-old woman with multiple comorbidities underwent surgical replacement of the aortic valve with a mechanical prosthetic valve after recurrent IE. After 10 years, IE recurred and the mechanical valve was surgically replaced with a bioprosthetic valve. Ten years later, severe heart failure developed due to severe paravalvular leak (PVL) caused by an aortic annulus abscess complicated by a paravalvular pseudoaneurysm fistula (PPF). The patient was deemed at prohibitive surgical risk and a catheter-based PVL closure procedure was planned. However, the interventional procedure was delayed several months due to the Covid-19 pandemic with progressive heart failure worsening. Despite an acute satisfactory result of the PPF transcatheter closure and a significant clinical improvement, the patient died 10 months later due to multiorgan failure. It is likely that this was due, at least in part, to the long treatment delay caused by the unprecedented strain on the healthcare system. Discussion: In patients at high surgical risk, early diagnosis and prompt interventional treatment of severe PVL are crucial for improving expectancy and quality of life. However, the recent outbreak of COVID-19 caused deferral of elective and semi-elective structural heart disease procedures (SHD) as in our case. Thus, a proactive and vigilant stance on managing SHD should be a priority even in the context of the COVID-19 pandemic.

Transcatheter aortic valve implantation in patients with unruptured aortic root pseudoaneurysm: an observational study

AIMS

Unruptured aortic root pseudoaneurysm (UARP) is a rare complication of aortic valve endocarditis. Infectious spread to the valvular annulus or myocardium can cause septic complications that manifest as wall thickening, and spontaneous abscess drainage leads to pseudoaneurysm formation. We report the first patient series in which transcatheter aortic valve implantation (TAVI) using a single valve-resolved aortic valvulopathy associated with UARP was performed.

METHODS

At our center, from December 2017 to October 2019, 138 patients underwent TAVI for aortic valve stenosis and/or regurgitation, 20 of whom (12 female patients, 8 male patients) had associated incidental UARP and were considered as our study population. The average age of these patients was 76.9 ± 5.2 years. All patients were assessed using preprocedural and postprocedural multimodality imaging, including transthoracic echocardiography, transesophageal echocardiography, and cardiac computed tomography angiography (CCTA).

RESULTS

In all cases, the final angiographic examination showed correct valve positioning with complete coverage of the false aneurysm. Post-TAVI CCTA showed presence of total or subtotal UARP thrombosis. The mean follow-up period was 17.5 months (12-23 months). During follow-up, imaging showed normal prosthetic valve function, no significant leakage (trace or mild), and complete UARP exclusion in all patients, without any complications.

CONCLUSION

In conclusion, percutaneous valve positioning can simultaneously solve pseudoaneurysm complications by excluding the sac and promoting thrombosis.

Imaging of Cardiac Infections: A Comprehensive Review and Investigation Flowchart for Diagnostic Workup

Infections of the cardiovascular system may present with nonspecific symptoms, and it is common for patients to undergo multiple investigations to arrive at the diagnosis. Echocardiography is central to the diagnosis of endocarditis and pericarditis. However, cardiac computed tomography (CT) and magnetic resonance imaging also play an additive role in these diagnoses; in fact, magnetic resonance imaging is central to the diagnosis of myocarditis. Functional imaging (fluorine-18 fluorodeoxyglucose-positron emission tomography/CT and radiolabeled white blood cell single-photon emission computed tomography/CT) is useful in the diagnosis in prosthesis-related and disseminated infection. This pictorial review will detail the most commonly encountered cardiovascular bacterial and viral infections, including coronavirus disease-2019, in clinical practice and provide an evidence basis for the selection of each imaging modality in the investigation of native tissues and common prostheses.

Endocarditis in Patients with Aortic Valve Prosthesis: Comparison between Surgical and Transcatheter Prosthesis

The interventional treatment of aortic stenosis is currently based on transcatheter aortic valve implantation/replacement (TAVI/TAVR) and surgical aortic valve replacement (SAVR). Prosthetic valve infective endocarditis (PVE) is the most worrisome complication after valve replacement, as it still carries high mortality and morbidity rate. Studies have not highlighted the differences in the occurrence of PVE in SAVR as opposed to TAVR, but the reported incidence rates are widely uneven. Literature portrays different microbiological profiles for SAVR and TAVR PVE: Staphylococcus, Enterococcus, and Streptococcus are the pathogens that are more frequently involved with differences regarding the timing from the date of the intervention. Imaging by means of transoesophageal echocardiography, and computed tomography (CT) Scan is essential in identifying vegetations, prosthesis dysfunction, dehiscence, periannular abscess, or aorto-ventricular discontinuity. In most cases, conservative medical treatment is not able to prevent fatal events and surgery represents the only viable option. The primary objectives of surgical treatment are radical debridement and the removal of infected tissues, the reconstruction of cardiac and aortic morphology, and the restoration of the aortic valve function. Different surgical options are discussed. Fast diagnosis, the adequacy of antibiotics treatment, and prompt interventions are essential in preventing the negative consequences of infective endocarditis (IE).

CT and MR Imaging Findings of Structural Heart Diseases Associated with Sudden Cardiac Death

급성 심장사는 증상이 시작된 후 한 시간 이내에 발생하는 심장 원인으로 인한 사망이다. 급성 심장사의 원인은 주로 부정맥이지만 동반할 수 있는 기저 심질환들을 사전에 진단하는 것은 장기적 위험을 예측하는 데 중요하다. 심장 CT와 심장 MR은 구조적 심질환을 진단하고 평가하는데 중요한 정보를 제공하여 급성 심장사의 위험을 예측하고 대비할 수 있게 한다. 따라서 임상적으로 중요한 급성 심장사의 위험을 증가시키는 다양한 원인과 영상 소견의 중요성에 대하여 중점적으로 살펴보고자 한다.

Cardiac CT angiography: normal and pathological anatomical features-a narrative review

The normal and pathological anatomy of the heart and coronary arteries are nowadays widely developed topics and constitute a fundamental part of the cultural background of the radiologist. The introduction of cardiac ECG-gated synchronized CT scanners with an ever-increasing number of detectors and with increasingly high structural characteristics (increase in temporal resolution, increase in contrast resolution with dual-source, dual energy scanners) allows the virtual measurement of anatomical in vivo structures complying with heart rate with submillimetric precision permitting to clearly depict the normal anatomy and follow the pathologic temporal evolution. Accordingly to these considerations, cardiac computed tomography angiography (CCTA) asserts itself as a gold standard method for the anatomical evaluation of the heart and permits to evaluate, verify, measure and characterize structural pathological alterations of both congenital and acquired degenerative diseases. Accordingly, CCTA is increasingly used as a prognostic model capable of modifying the outcome of diseased patients in planning interventions and in the post-surgical/interventional follow-up. The profound knowledge of cardiac anatomy and function through highly detailed CCTA analysis is required to perform an efficient and optimal use in real-world clinical practice.

Imaging evaluation using computed tomography after ascending aortic graft repair

Prosthetic aortic graft repair is employed in the management of various conditions such as annuloaortic ectasia, ascending aortic aneurysm, type A aortic dissection, and aortic root abscess. Correct interpretation of post-surgical prosthetic graft complications requires familiarity with the expected normal cross-sectional imaging appearance as well knowledge of additional surgical materials used in the repair, which could influence the imaging appearance. Multiple life-threatening complications of a prosthetic ascending aortic graft can be seen in the aorta and vicinity of the operative field. Complications can arise from involvement of the prosthetic aortic graft per se or secondary involvement of the coronary arteries, mediastinum, and sternotomy site. The optimal imaging protocol using multidetector computed tomography allows accurate interpretation of the expected benign postoperative changes as well as complications associated with the prosthetic graft, and differentiation of true complications from their mimickers. This review focuses on the normal imaging appearance of a prosthetic aortic graft on multidetector computed tomography, and imaging evaluation of multiple post-surgical complications that could arise after repair of the ascending aorta and the aortic valve.

Aortic valvular imaging with cardiovascular magnetic resonance: seeking for comprehensiveness

Cardiovascular magnetic resonance (CMR) has an emerging role in aortic valve disease evaluation, becoming an all-in-one technique. CMR evaluation of the anatomy and flow through the aortic valve has a higher reproducibility than echocardiography. Its unique ability of in vivo myocardial tissue characterization, significantly improves the risk stratification and management of patients. In addition, CMR is equivalent to cardiac CT angiography for trans-aortic valvular implantation and surgical aortic valve replacement planning; on the other hand, its role in the evaluation of ventricular function improving and post-treatment complications is undisputed. This review encompasses the existing literature regarding the role of CMR in aortic valve disease, exploring all the aspects of the disease, from diagnosis to prognosis.

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.

A Sensible Approach to Diagnosing Cardiac Aneurysms, Pseudoaneurysms and Common Mimickers

The heart can manifest a spectrum of focal convexities that range from insignificant crypts and diverticula to clinically relevant aneurysms and pseudoaneurysms. The distinction of a clinically significant lesion from a minor focal convexity can be challenging. This article outlines the various types of focal convexities on the basis of location within the heart and discusses unique morphologic and functional features to further characterize these entities. We also highlight the most critical clinical consequences of cardiac aneurysms and pseudoaneurysms such as thromboembolic events, aneurysm ruptures, intracardiac shunting, hemopericardium, and arrhythmias.

Hybrid cardiac imaging using PET/MRI: a joint position statement by the European Society of Cardiovascular Radiology (ESCR) and the European Association of Nuclear Medicine (EANM)

Positron emission tomography (PET) and magnetic resonance imaging (MRI) have both been used for decades in cardiovascular imaging. Since 2010, hybrid PET/MRI using sequential and integrated scanner platforms has been available, with hybrid cardiac PET/MR imaging protocols increasingly incorporated into clinical workflows. Given the range of complementary information provided by each method, the use of hybrid PET/MRI may be justified and beneficial in particular clinical settings for the evaluation of different disease entities. In the present joint position statement, we critically review the role and value of integrated PET/MRI in cardiovascular imaging, provide a technical overview of cardiac PET/MRI and practical advice related to the cardiac PET/MRI workflow, identify cardiovascular applications that can potentially benefit from hybrid PET/MRI, and describe the needs for future development and research. In order to encourage its wide dissemination, this article is freely accessible on the European Radiology and European Journal of Hybrid Imaging web sites.

KEY POINTS

• Studies and case-reports indicate that PET/MRI is a feasible and robust technology. • Promising fields of application include a variety of cardiac conditions. • Larger studies are required to demonstrate its incremental and cost-effective value. • The translation of novel radiopharmaceuticals and MR-sequences will provide exciting new opportunities.

Pericardial mass in a 71-year-old man

CLINICAL INTRODUCTION: A 71-year-old man, with a history of chronic aortic regurgitation and negative follow-up after bladder cancer resection 10 months before, had an aortic valve surgery. Two months after, a mass near the right side of the heart had been detected by transthoracic echocardiography performed for dyspnoea, without a cough or fever. The quality of ultrasound images did not allow for an appropriate evaluation due to the outcomes of the sternotomy and the presence of calcified pachypleurite. In order to evaluate this finding, coronary CT (CCT) (figure 1A,B) and positron-emission tomography with 2-[18F] fluoro-2-deoxy-D-glucose (FDG-PET) (figure 1C) were performed. Finally, a cardiac magnetic resonance (CMR) was requested (figure 1D-F, see online supplementary videos).heartjnl;104/23/1936/F1F1F1Figure 1(A) Short axis image of early contrast enhancement phase coronary CT (CCT); (B) short axis of delayed phase of the same CCT; (C) lesion on positron-emission tomography with 2-[18F] fluoro-2-deoxy-D-glucose image (white arrow); CMR short axis (D) T2-weighted image with fat saturation; (E) T1-weighted image with fat-saturation; (F) T1-weighted image without fat-saturation. QUESTION: Which of the following is the most likely diagnosis of the pericardial mass?Primary pericardial tumour.Pericardial metastasis.Intrapericardial abscess.Intrapericardial haematoma.

Cardiac Computed Tomography: Before and After Cardiac Surgery

Cardiac computed tomography angiography (CCTA) is a noninvasive imaging technique that has been rapidly adopted into clinical practice. Over the past decade, technological advances have improved CCTA accuracy, and there is an increasing amount of data supporting its prognostic value in the assessment of coronary artery disease. Recently, "appropriate use criteria" has been used as a tool to minimize inappropriate testing and reduce patient exposure to unnecessary risk and inconclusive studies. This review will summarize the appropriate uses of CCTA in patients before and after cardiac surgery. Although the most common indication for CCTA is assessment of patency of native coronary arteries, other potential perioperative uses (eg, assessment of congenital heart disease, valvular heart disease, pericardial disease, myocardial disease, cardiac anatomy, bypass grafts, aortic disease, and cardiac masses) will be reviewed.

A Review of the Use of Cardiac Computed Tomography for Evaluating the Mitral Valve before and after Mitral Valve Repair

The role of cardiac computed tomography (CT) for evaluating the mitral valve (MV) has been limited since echocardiography is the main method of evaluation. However, recent advances in cardiac CT have enable detailed evaluation of the anatomy and geometry of the MV. We describe assessments of the anatomy and coaptation geometric parameters of normal MVs, and also review repair of diseased/damaged MV. We also discuss pre- and post-surgical imaging of MV pathology using cardiac CT and various CT images. We found that cardiac CT could be used as an alternative imaging modality to echocardiography for pre-operative MV evaluation and to predict clinical outcomes following repair.

Diagnostic value of imaging in infective endocarditis: a systematic review

Sensitivity and specificity of the modified Duke criteria for native valve endocarditis are both suboptimal, at approximately 80%. Diagnostic accuracy for intracardiac prosthetic material-related infection is even lower. Non-invasive imaging modalities could potentially improve diagnosis of infective endocarditis; however, their diagnostic value is unclear. We did a systematic literature review to critically appraise the evidence for the diagnostic performance of these imaging modalities, according to PRISMA and GRADE criteria. We searched PubMed, Embase, and Cochrane databases. 31 studies were included that presented original data on the performance of electrocardiogram (ECG)-gated multidetector CT angiography (MDCTA), ECG-gated MRI, ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET/CT, and leucocyte scintigraphy in diagnosis of native valve endocarditis, intracardiac prosthetic material-related infection, and extracardiac foci in adults. We consistently found positive albeit weak evidence for the diagnostic benefit of ¹⁸F-FDG PET/CT and MDCTA. We conclude that additional imaging techniques should be considered if infective endocarditis is suspected. We propose an evidence-based diagnostic work-up for infective endocarditis including these non-invasive techniques.

Multimodality imaging in a late septic infection of aortic graft

A 70-year-old diabetic female patient presented with fatigue, headaches, hallucinations and shivers following a history of sinusitis and ophthalmitis. She had an aortic surgery performed 7 years ago for a stenotic and regurgitant aortic valve with aneurysm of the ascending aorta. Work-up brain MRI revealed septic–embolic encephalitis. Multimodality cardiovascular imaging showed abnormal anterior wall of the ascending aortic graft with vegetation extending into the lumen. Blood culture was only positive for Aggregatibacter actinomycetemcomitans, an uncommon cause of infective endocarditis. During aortic surgery, the intraluminal vegetation with suppurated perigraft tissue was confirmed.

Novel imaging strategies for the detection of prosthetic heart valve obstruction and endocarditis

Prosthetic heart valve (PHV) dysfunction remains difficult to recognise correctly by two-dimensional (2D) transthoracic and transoesophageal echocardiography (TTE/TEE). ECG-triggered multidetector-row computed tomography (MDCT), 18-fluorine-fluorodesoxyglucose positron emission tomography including low-dose CT (FDG-PET) and three-dimensional transoesophageal echocardiography (3D-TEE) may have additional value. This paper reviews the role of these novel imaging tools in the field of PHV obstruction and endocarditis.

For acquired PHV obstruction, MDCT is of additional value in mechanical PHVs to differentiate pannus from thrombus as well as to dynamically study leaflet motion and opening/closing angles. For biological PHV obstruction, additional imaging is not beneficial as it does not change patient management. When performed on top of 2D-TTE/TEE, MDCT has additional value for the detection of both vegetations and pseudoaneurysms/abscesses in PHV endocarditis. FDG-PET has no complementary value for the detection of vegetations; however, it appears more sensitive in the early detection of pseudoaneurysms/abscesses. Furthermore, FDG-PET enables the detection of metastatic and primary extra-cardiac infections. Evidence for the additional value of 3D-TEE is scarce.

As clinical implications are major, clinicians should have a low threshold to perform additional MDCT in acquired mechanical PHV obstruction. For suspected PHV endocarditis, both FDG-PET and MDCT have complementary value.

ECG-gated MDCT after aortic and mitral valve surgery

OBJECTIVE

The purpose of this article is to review the utility of ECG-gated MDCT in evaluating postsurgical findings in aortic and mitral valves. Normal and pathologic findings after aortic and mitral valve corrective surgery are shown in correlation with the findings of the traditionally used imaging modalities echocardiography and fluoroscopy to assist in accurate noninvasive anatomic and dynamic evaluation of postsurgical valvular abnormalities.

CONCLUSION

Because of its superior spatial and adequate temporal resolution, ECG-gated MDCT has emerged as a robust diagnostic tool in the evaluation and treatment of patients with postsurgical valvular abnormalities.

Multidetector CT findings of complications of surgical and endovascular treatment of aortic aneurysms

Aortic aneurysms remain a significant problem in the population, and there is a concerted effort to identify, define, image, and treat these conditions to ultimately improve outcomes. The rapid development of diagnostic modalities, operative strategies, and endovascular techniques within the realm of this aortic disease has transformed the field and broadened the spectrum of patients that can be treated with minimally invasive techniques. This investigation has a broad spectrum of normal expected findings that must be differentiated from early or late complications in which intervention is required. In this article, normal and abnormal postoperative and post-TEVAR/EVAR MDCT findings are described.

[Imaging following valve replacement]

Patients who undergo heart valve replacement require lifelong cardiac follow-up care. Although the primary pathology of the patient is treated by valve replacement, the risk of postoperative complications and structural failure of the implanted device requires regular check-ups where imaging plays an important role. Immediately after surgery reference values regarding prosthetic and cardiac function for further check-ups are obtained. Transthoracic and transesophageal echocardiography are the imaging modalities of choice for standard examination and follow-up due to their availability and low costs. However, when it comes to identification of complications they are often insufficient. Magnetic resonance imaging (MRI) and computed tomography (CT) play an increasingly important role as complementary modalities for the detection and monitoring of complications after valve replacement. The following article gives an overview of the current non-invasive examination methods and the use in the investigation of postoperative complications.