Cardiac magnetic resonance in advanced heart failure.

Heart failure (HF) is a chronic and progressive disease that often progresses to an advanced stage where conventional therapy is insufficient to relieve patients' symptoms. Despite the availability of advanced therapies such as mechanical circulatory support or heart transplantation, the complexity of defining advanced HF, which requires multiple parameters and multimodality assessment, often leads to delays in referral to dedicated specialists with the result of a worsening prognosis. In this review, we aim to explore the role of cardiac magnetic resonance (CMR) in advanced HF by showing how CMR is useful at every step in managing these patients: from diagnosis to prognostic stratification, hemodynamic evaluation, follow-up and advanced therapies such as heart transplantation. The technical challenges of scanning advanced HF patients, which often require troubleshooting of intracardiac devices and dedicated scans, will be also discussed.

Cardiovascular Magnetic Resonance Reference Ranges From the Healthy Hearts Consortium.

BACKGROUND: The absence of population-stratified cardiovascular magnetic resonance (CMR) reference ranges from large cohorts is a major shortcoming for clinical care. OBJECTIVES: This paper provides age-, sex-, and ethnicity-specific CMR reference ranges for atrial and ventricular metrics from the Healthy Hearts Consortium, an international collaborative comprising 9,088 CMR studies from verified healthy individuals, covering the complete adult age spectrum across both sexes, and with the highest ethnic diversity reported to date. METHODS: CMR studies were analyzed using certified software with batch processing capability (cvi42, version 5.14 prototype, Circle Cardiovascular Imaging) by 2 expert readers. Three segmentation methods (smooth, papillary, anatomic) were used to contour the endocardial and epicardial borders of the ventricles and atria from long- and short-axis cine series. Clinically established ventricular and atrial metrics were extracted and stratified by age, sex, and ethnicity. Variations by segmentation method, scanner vendor, and magnet strength were examined. Reference ranges are reported as 95% prediction intervals. RESULTS: The sample included 4,452 (49.0%) men and 4,636 (51.0%) women with average age of 61.1 ± 12.9 years (range: 18-83 years). Among these, 7,424 (81.7%) were from White, 510 (5.6%) South Asian, 478 (5.3%) mixed/other, 341 (3.7%) Black, and 335 (3.7%) Chinese ethnicities. Images were acquired using 1.5-T (n = 8,779; 96.6%) and 3.0-T (n = 309; 3.4%) scanners from Siemens (n = 8,299; 91.3%), Philips (n = 498; 5.5%), and GE (n = 291, 3.2%). CONCLUSIONS: This work represents a resource with healthy CMR-derived volumetric reference ranges ready for clinical implementation.

ESR Essentials: ten steps to cardiac MR-practice recommendations by ESCR.

Cardiovascular MR imaging has become an indispensable noninvasive tool in diagnosing and monitoring a broad range of cardiovascular diseases. Key to its clinical success and efficiency are appropriate clinical indication triage, technical expertise, patient safety, standardized preparation and execution, quality assurance, efficient post-processing, structured reporting, and communication and clinical integration of findings. Technological advancements are driving faster, more accessible, and cost-effective approaches. This ESR Essentials article presents a ten-step guide for implementing a cardiovascular MR program, covering indication assessments, optimized imaging, post-processing, and detailed reporting. Future goals include streamlined protocols, improved tissue characterization, and automation for greater standardization and efficiency. CLINICAL RELEVANCE STATEMENT: The growing clinical role of cardiovascular MR in risk assessment, diagnosis, and treatment planning highlights the necessity for radiologists to achieve expertise in this modality, advancing precision medicine and healthcare efficiency. KEY POINTS: • Cardiovascular MR is essential in diagnosing and monitoring many acute and chronic cardiovascular pathologies. • Features such as technical expertise, quality assurance, patient safety, and optimized tailored imaging protocols, among others, are essential for a successful cardiovascular MR program. • Ongoing technological advances will push rapid multi-parametric cardiovascular MR, thus improving accessibility, patient comfort, and cost-effectiveness. KEY POINTS: • Cardiovascular MR is essential in diagnosing and monitoring a wide array of cardiovascular pathologies (Level of Evidence: High). • A successful cardiovascular MR program depends on standardization (Level of Evidence: Low). • Future developments will increase the efficiency and accessibility of cardiovascular MR (Level of Evidence: Low).

The influence of motion-compensated reconstruction on coronary artery analysis for a dual-layer detector CT system: a dynamic phantom study.

OBJECTIVES: Cardiac motion artifacts hinder the assessment of coronary arteries in coronary computed tomography angiography (CCTA). We investigated the impact of motion compensation reconstruction (MCR) on motion artifacts in CCTA at various heart rates (HR) using a dynamic phantom. MATERIALS AND METHODS: An artificial hollow coronary artery (5-mm diameter lumen) filled with iodinated contrast agent (400 HU at 120 kVp), positioned centrally in an anthropomorphic chest phantom, was scanned using a dual-layer spectral detector CT. The artery was translated at constant horizontal velocities (0-80 mm/s, increment of 10 mm/s). For each velocity, five CCTA scans were repeated using a clinical protocol. Motion artifacts were quantified using the in-plane motion area. Regression analysis was performed to calculate the reduction in motion artifacts provided by MCR, by division of the slopes of non-MCR and MCR fitted lines. RESULTS: Reference mean (95% confidence interval) motion artifact area was 24.9 mm2 (23.8, 26.0). Without MCR, motion artifact areas for velocities exceeding 20 mm/s were significantly larger (up to 57.2 mm2 (40.1, 74.2)) than the reference. With MCR, no significant differences compared to the reference were shown for all velocities, except for 70 mm/s (29.0 mm2 (27.0, 31.0)). The slopes of the fitted data were 0.44 and 0.04 for standard and MCR reconstructions, respectively, resulting in an 11-time motion artifact reduction. CONCLUSION: MCR may improve CCTA assessment in patients by reducing coronary artery motion artifacts, especially in those with elevated HR who cannot receive beta blockers or do not attain the targeted HR. CLINICAL RELEVANCE STATEMENT: This vendor-specific motion compensation reconstruction may improve coronary computed tomography angiography assessment in patients by reduction of coronary artery motion artifacts, especially in those with elevated various heart rates (HR) who cannot receive beta blockers or do not attain the targeted HR. KEY POINTS: • Motion artifacts are known to hinder the assessment of coronary arteries on coronary CT angiography (CCTA), leading to more non-diagnostic scans. • This dynamic phantom study shows that motion compensation reconstruction (MCR) reduces motion artifacts at various velocities, which may help to decrease the number of non-diagnostic scans. • MCR in this study showed to reduce motion artifacts 11-fold.

Automatic Coronary Artery Plaque Quantification and CAD-RADS Prediction Using Mesh Priors.

Coronary artery disease (CAD) remains the leading cause of death worldwide. Patients with suspected CAD undergo coronary CT angiography (CCTA) to evaluate the risk of cardiovascular events and determine the treatment. Clinical analysis of coronary arteries in CCTA comprises the identification of atherosclerotic plaque, as well as the grading of any coronary artery stenosis typically obtained through the CAD-Reporting and Data System (CAD-RADS). This requires analysis of the coronary lumen and plaque. While voxel-wise segmentation is a commonly used approach in various segmentation tasks, it does not guarantee topologically plausible shapes. To address this, in this work, we propose to directly infer surface meshes for coronary artery lumen and plaque based on a centerline prior and use it in the downstream task of CAD-RADS scoring. The method is developed and evaluated using a total of 2407 CCTA scans. Our method achieved lesion-wise volume intraclass correlation coefficients of 0.98, 0.79, and 0.85 for calcified, non-calcified, and total plaque volume respectively. Patient-level CAD-RADS categorization was evaluated on a representative hold-out test set of 300 scans, for which the achieved linearly weighted kappa ( κ ) was 0.75. CAD-RADS categorization on the set of 658 scans from another hospital and scanner led to a κ of 0.71. The results demonstrate that direct inference of coronary artery meshes for lumen and plaque is feasible, and allows for the automated prediction of routinely performed CAD-RADS categorization.

Cardiac CT in CRT as a Singular Imaging Modality for Diagnosis and Patient-Tailored Management.

Between 30-40% of patients with cardiac resynchronization therapy (CRT) do not show an improvement in left ventricular (LV) function. It is generally known that patient selection, LV lead implantation location, and device timing optimization are the three main factors that determine CRT response. Research has shown that image-guided CRT placement, which takes into account both anatomical and functional cardiac properties, positively affects the CRT response rate. In current clinical practice, a multimodality imaging approach comprised of echocardiography, cardiac magnetic resonance imaging, or nuclear medicine imaging is used to capture these features. However, with cardiac computed tomography (CT), one has an all-in-one acquisition method for both patient selection and the division of a patient-tailored, image-guided CRT placement strategy. This review discusses the applicability of CT in CRT patient identification, selection, and guided placement, offering insights into potential advancements in optimizing CRT outcomes.

Cardiovascular Magnetic Resonance for Patients With COVID-19.

COVID-19 is associated with myocardial injury caused by ischemia, inflammation, or myocarditis. Cardiovascular magnetic resonance (CMR) is the noninvasive reference standard for cardiac function, structure, and tissue composition. CMR is a potentially valuable diagnostic tool in patients with COVID-19 presenting with myocardial injury and evidence of cardiac dysfunction. Although COVID-19-related myocarditis is likely infrequent, COVID-19-related cardiovascular histopathology findings have been reported in up to 48% of patients, raising the concern for long-term myocardial injury. Studies to date report CMR abnormalities in 26% to 60% of hospitalized patients who have recovered from COVID-19, including functional impairment, myocardial tissue abnormalities, late gadolinium enhancement, or pericardial abnormalities. In athletes post-COVID-19, CMR has detected myocarditis-like abnormalities. In children, multisystem inflammatory syndrome may occur 2 to 6 weeks after infection; associated myocarditis and coronary artery aneurysms are evaluable by CMR. At this time, our understanding of COVID-19-related cardiovascular involvement is incomplete, and multiple studies are planned to evaluate patients with COVID-19 using CMR. In this review, we summarize existing studies of CMR for patients with COVID-19 and present ongoing research. We also provide recommendations for clinical use of CMR for patients with acute symptoms or who are recovering from COVID-19.

Functional cardiac CT-Going beyond Anatomical Evaluation of Coronary Artery Disease with Cine CT, CT-FFR, CT Perfusion and Machine Learning.

The aim of this review is to provide an overview of different functional cardiac CT techniques which can be used to supplement assessment of the coronary arteries to establish the significance of coronary artery stenoses. We focus on cine-CT, CT-FFR, CT-myocardial perfusion and how developments in machine learning can supplement these techniques.

Deep learning from dual-energy information for whole-heart segmentation in dual-energy and single-energy non-contrast-enhanced cardiac CT.

PURPOSE: Deep learning-based whole-heart segmentation in coronary computed tomography angiography (CCTA) allows the extraction of quantitative imaging measures for cardiovascular risk prediction. Automatic extraction of these measures in patients undergoing only non-contrast-enhanced CT (NCCT) scanning would be valuable, but defining a manual reference standard that would allow training a deep learning-based method for whole-heart segmentation in NCCT is challenging, if not impossible. In this work, we leverage dual-energy information provided by a dual-layer detector CT scanner to obtain a reference standard in virtual non-contrast (VNC) CT images mimicking NCCT images, and train a three-dimensional (3D) convolutional neural network (CNN) for the segmentation of VNC as well as NCCT images. METHODS: Eighteen patients were scanned with and without contrast enhancement on a dual-layer detector CT scanner. Contrast-enhanced acquisitions were reconstructed into a CCTA and a perfectly aligned VNC image. In each CCTA image, manual reference segmentations of the left ventricular (LV) myocardium, LV cavity, right ventricle, left atrium, right atrium, ascending aorta, and pulmonary artery trunk were obtained and propagated to the corresponding VNC image. These VNC images and reference segmentations were used to train 3D CNNs in a sixfold cross-validation for automatic segmentation in either VNC images or NCCT images reconstructed from the non-contrast-enhanced acquisition. Automatic segmentation in VNC images was evaluated using the Dice similarity coefficient (DSC) and average symmetric surface distance (ASSD). Automatically determined volumes of the cardiac chambers and LV myocardium in NCCT were compared to reference volumes of the same patient in CCTA by Bland-Altman analysis. An additional independent multivendor multicenter set of single-energy NCCT images from 290 patients was used for qualitative analysis, in which two observers graded segmentations on a five-point scale. RESULTS: Automatic segmentations in VNC images showed good agreement with reference segmentations, with an average DSC of 0.897 ± 0.034 and an average ASSD of 1.42 ± 0.45 mm. Volume differences [95% confidence interval] between automatic NCCT and reference CCTA segmentations were -19 [-67; 30] mL for LV myocardium, -25 [-78; 29] mL for LV cavity, -29 [-73; 14] mL for right ventricle, -20 [-62; 21] mL for left atrium, and -19 [-73; 34] mL for right atrium, respectively. In 214 (74%) NCCT images from the independent multivendor multicenter set, both observers agreed that the automatic segmentation was mostly accurate (grade 3) or better. CONCLUSION: Our automatic method produced accurate whole-heart segmentations in NCCT images using a CNN trained with VNC images from a dual-layer detector CT scanner. This method might enable quantification of additional cardiac measures from NCCT images for improved cardiovascular risk prediction.

Surgically implanted aortic valve bioprostheses deform after implantation: insights from computed tomography.

OBJECTIVE: Little is known about the prevalence and degree of deformation of surgically implanted aortic biological valve prostheses (bio-sAVRs). We assessed bio-sAVR deformation using multidetector-row computed tomography (MDCT). METHODS: Three imaging databases were searched for patients with MDCT performed after bio-sAVR implantation. Minimal and maximal valve ring diameters were obtained in systole and/or diastole, depending on the acquired cardiac phase(s). The eccentricity index (EI) was calculated as a measure of deformation as (1 - (minimal diameter/maximal diameter)) × 100%. EI of < 5% was considered none or trivial deformation, 5-10% mild deformation, and > 10% non-circular. Indications for MDCT and implanted valve type were retrieved. RESULTS: One hundred fifty-two scans of bio-sAVRs were included. One hundred seventeen measurements were performed in systole and 35 in diastole. None or trivial deformation (EI < 5%) was seen in 67/152 (44%) of patients. Mild deformation (EI 5-10%) was seen in 59/152 (39%) and non-circularity was found in 26/152 (17%) of cases. Overall, median EI was 5.5% (IQR 3.4-7.8). In 77 patients, both systolic and diastolic measurements were performed from the same scan. For these scans, the median EI was 6.5% (IQR 3.4-10.2) in systole and 5.1% (IQR3.1-7.6) in diastole, with a significant difference between both groups (p = 0.006). CONCLUSIONS: Surgically implanted aortic biological valve prostheses show mild deformation in 39% of cases and were considered non-circular in 17% of studied valves. KEY POINTS: • Deformation of surgically implanted aortic valve bioprostheses (bio-sAVRs) can be adequately assessed using MDCT. • Bio-sAVRs show at least mild deformation (eccentricity index > 5%) in 56% of studied cases and were considered non-circular (eccentricity index > 10%) in 17% of studied valves. • The higher deformity rate found in bio-sAVRs with (suspected) valve pathology could suggest that geometric deformity may play a role in leaflet malformation and thrombus formation similar to that of transcatheter heart valves.

Suboptimal Quality and High Risk of Bias in Diagnostic Test Accuracy Studies at Chest Radiography and CT in the Acute Setting of the COVID-19 Pandemic: A Systematic Review.

PURPOSE: To synthesize the literature on diagnostic test accuracy of chest radiography, CT, and US for the diagnosis of coronavirus disease 2019 (COVID-19) in patients suspected of having COVID-19 in a hospital setting and evaluate the extent of suboptimal reporting and risk of bias. MATERIALS AND METHODS: A systematic search was performed (April 26, 2020) in EMBASE, PubMed, and Cochrane to identify chest radiographic, CT, or US studies in adult patients suspected of having COVID-19, using reverse-transcription polymerase chain reaction test or clinical consensus as the standard of reference. Two × two contingency tables were reconstructed, and test sensitivity, specificity, positive predictive values, and negative predictive values were recalculated. Reporting quality was evaluated by adherence to the Standards for Reporting of Diagnostic Accuracy Studies (STARD), and risk of bias was evaluated by adherence to the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). RESULTS: Thirteen studies were eligible (CT = 12; chest radiography = 1; US = 0). Recalculated CT sensitivity and specificity ranged between 0.57 and 0.97, and 0.37 and 0.94, respectively, and positive predictive values and negative predictive values ranged between 0.59 and 0.92 and 0.57 and 0.96, respectively. On average, studies complied with only 35% of the STARD-guideline items. No study scored low risk of bias for all QUADAS-2 domains (patient selection, index test, reference test, and flow and timing). High risk of bias in more than one domain was scored in 10 of 13 studies (77%). CONCLUSION: Reported CT test accuracy for COVID-19 diagnosis varies substantially. The validity and generalizability of these findings is complicated by poor adherence to reporting guidelines and high risk of bias, which are most likely due to the need for urgent publication of findings in the first months of the COVID-19 pandemic.Supplemental material is available for this article.© RSNA, 2020.

Radiation dose reduction in pediatric great vessel stent computed tomography using iterative reconstruction: A phantom study.

BACKGROUND: To study dose reduction using iterative reconstruction (IR) for pediatric great vessel stent computed tomography (CT). METHODS: Five different great vessel stents were separately placed in a gel-containing plastic holder within an anthropomorphic chest phantom. The stent lumen was filled with diluted contrast gel. CT acquisitions were performed at routine dose, 52% and 81% reduced dose and reconstructed with filtered back projection (FBP) and IR. Objective image quality in terms of noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) as well as subjective image quality were evaluated. RESULTS: Noise, SNR and CNR were improved with IR at routine and 52% reduced dose, compared to FBP at routine dose. The lowest dose level resulted in decreased objective image quality with both FBP and IR. Subjective image quality was excellent at all dose levels. CONCLUSION: IR resulted in improved objective image quality at routine dose and 52% reduced dose, while objective image quality deteriorated at 81% reduced dose. Subjective image quality was not affected by dose reduction.

Diagnostic evaluation and treatment strategy in patients with suspected prosthetic heart valve dysfunction: The incremental value of MDCT.

BACKGROUND: In patients with suspected prosthetic heart valve (PHV) dysfunction, routine evaluation echocardiography and fluoroscopy may provide unsatisfactory results for identifying the cause of dysfunction. This study assessed the value of MDCT as a routine, complementary imaging modality in suspected PHV-dysfunction for diagnosing the cause of PHV dysfunction and proposing a treatment strategy. METHODS: Patients with suspected PHV dysfunction were prospectively recruited. All patients underwent routine diagnostic work-up (TTE, TEE ± fluoroscopy) and additional MDCT imaging. An expert panel reviewed all cases and assessed the diagnosis and treatment strategy, first based on routine evaluation only, second with additional MDCT information. RESULTS: Forty-two patients were included with suspected PHV obstruction (n = 30) and PHV regurgitation (n = 12). The addition of MDCT showed incremental value to routine evaluation in 26/30 (87%) cases for detecting the specific cause of PHV obstruction and in 7/12 (58%) regurgitation cases for assessment of complications and surgical planning. The addition of MDCT resulted in treatment strategy change in 8/30 (27%) patients with suspected obstruction and 3/12 (25%) patients with regurgitation. CONCLUSION: In addition to echocardiography and fluoroscopy, MDCT may identify the cause of PHV dysfunction and alter the treatment strategy.

Baseline MDCT findings after prosthetic heart valve implantation provide important complementary information to echocardiography for follow-up purposes.

OBJECTIVES: Recent studies have proposed additional multidetector-row CT (MDCT) for prosthetic heart valve (PHV) dysfunction. References to discriminate physiological from pathological conditions early after implantation are lacking. We present baseline MDCT findings of PHVs 6 weeks post implantation. METHODS: Patients were prospectively enrolled and TTE was performed according to clinical guidelines. 256-MDCT images were systematically assessed for leaflet excursions, image quality, valve-related artefacts, and pathological and additional findings. RESULTS: Forty-six patients were included comprising 33 mechanical and 16 biological PHVs. Overall, MDCT image quality was good and relevant regions remained reliably assessable despite mild-moderate PHV-artefacts. MDCT detected three unexpected valve-related pathology cases: (1) prominent subprosthetic tissue, (2) pseudoaneurysm and (3) extensive pseudoaneurysms and valve dehiscence. The latter patient required valve surgery to be redone. TTE only showed trace periprosthetic regurgitation, and no abnormalities in the other cases. Additional findings were: tilted aortic PHV position (n = 3), pericardial haematoma (n = 3) and pericardial effusion (n = 3). Periaortic induration was present in 33/40 (83 %) aortic valve patients. CONCLUSIONS: MDCT allowed evaluation of relevant PHV regions in all valves, revealed baseline postsurgical findings and, despite normal TTE findings, detected three cases of unexpected, clinically relevant pathology. KEY POINTS: • Postoperative MDCT presents baseline morphology relevant for prosthetic valve follow-up. • 83 % of patients show periaortic induration 6 weeks after aortic valve replacement. • MDCT detected three cases of clinically relevant pathology not found with TTE. • Valve dehiscence detection by MDCT required redo valve surgery in one patient. • MDCT is a suitable and complementary imaging tool for follow-up purposes.

Does the aortic annulus undergo conformational change throughout the cardiac cycle? A systematic review.

Accurate annular sizing in transcatheter aortic valve implantation (TAVI) planning is essential. It is now widely recognized that the annulus is an oval structure in most patients, but it remains unclear if the annulus undergoes change in size and shape during the cardiac cycle that may impact prosthesis size selection. Our aim was to assess whether the aortic annulus undergoes dynamic conformational change during the cardiac cycle and to evaluate possible implications for prosthesis size selection. We performed a systematic search in PubMed and Embase databases and reviewed all available literature on aortic annulus measurements in at least two cardiac phases. Twenty-nine articles published from 2001 to 2014 were included. In total, 2021 subjects with and without aortic stenosis were evaluated with a mean age ranging from 11 ± 3.6 to 84.9 ± 7.2 years. Two- and three-dimensional echocardiography was performed in six studies each, magnetic resonance imaging was used in one and computed tomography in 17 studies. In general, the aortic annulus was more circular in systole and predominantly oval in diastole. Whereas the annular long-axis diameter showed insignificant change throughout the cycle, the short-axis diameter, area, and perimeter were significantly larger in systole compared with diastole. Hence, the aortic annulus does undergo dynamic changes during the cardiac cycle. In patients with large conformational changes, diastolic compared with systolic measurements can result in undersizing TAVI prostheses. Due to the complex annular anatomy and dynamic change, three-dimensional assessment in multiple phases has utmost importance in TAVI planning to improve prosthesis sizing.

Multimodality Imaging Assessment of Prosthetic Heart Valves.

Echocardiography and fluoroscopy are the main techniques for prosthetic heart valve (PHV) evaluation, but because of specific limitations they may not identify the morphological substrate or the extent of PHV pathology. Cardiac computed tomography (CT) and magnetic resonance imaging (MRI) have emerged as new potential imaging modalities for valve prostheses. We present an overview of the possibilities and pitfalls of CT and MRI for PHV assessment based on a systematic literature review of all experimental and patient studies. For this, a comprehensive systematic search was performed in PubMed and Embase on March 24, 2015, containing CT/MRI and PHV synonyms. Our final selection yielded 82 articles on surgical valves. CT allowed adequate assessment of most modern PHVs and complemented echocardiography in detecting the obstruction cause (pannus or thrombus), bioprosthesis calcifications, and endocarditis extent (valve dehiscence and pseudoaneurysms). No clear advantage over echocardiography was found for the detection of vegetations or periprosthetic regurgitation. Whereas MRI metal artifacts may preclude direct prosthesis analysis, MRI provided information on PHV-related flow patterns and velocities. MRI demonstrated abnormal asymmetrical flow patterns in PHV obstruction and allowed prosthetic regurgitation assessment. Hence, CT shows great clinical relevance as a complementary imaging tool for the diagnostic work-up of patients with suspected PHV obstruction and endocarditis. MRI shows potential for functional PHV assessment although more studies are required to provide diagnostic reference values to allow discrimination of normal from pathological conditions.

Reliability, Agreement, and Presentation of a Reference Standard for Assessing Implanted Heart Valve Sizes by Multidetector-Row Computed Tomography.

The implanted prosthetic heart valve (PHV) size is vital for the evaluation of suspected PHV dysfunction and in case of reoperation or valve-in-valve transcatheter approaches. The labeled size is not always known, and discrepancies exist between manufacturers' labeled sizes and true sizes. Reproducible methods for noninvasive PHV size assessment are lacking. We determined the reliability and agreement of PHV size measurements using multidetector-row computed tomography (MDCT) and provide reference values of MDCT measurements compared with manufacturer specifications. In vitro, 15 different PHV types in available sizes (total n = 63) were imaged. In vivo, available MDCT acquisitions of patients with PHVs were retrospectively gathered in 2 centers, and 230 patients with 249 PHVs were included. Inner valve area and area-derived diameter were measured in all PHVs. For mechanical PHVs, the inner diameter was also measured. Data were analyzed using the intraclass correlation coefficient and Bland-Altman plots and related to manufacturer specifications. Measurements could be obtained for all PHV types, except the Björk-Shiley (n = 7) because of severe valve-related artifacts hampering the image quality. Intrarater and interrater reliability was excellent for biological and mechanical PHVs (intraclass correlation coefficients ≥0.903). Agreement was good for all measurements with an overall maximal mean difference (95% confidence interval) of -2.61 mm(2) (-37.9 to 32.7), -0.1 mm (-1.1 to 1.0), and 0 mm (-0.4 to 0.3) for valve area, area-derived diameter, and inner diameter, respectively. MDCT reliably discriminated consecutive PHV sizes as labeled by the manufacturer because the absolute ranges for the measurements never overlapped. In conclusion, MDCT allows assessment of the implanted PHV size with excellent reliability and agreement and can discriminate between PHV sizes for contemporary prostheses. MDCT can be used to noninvasively identify the manufacturer-labeled PHV size.

Sublingual Nitroglycerin Administration in Coronary Computed Tomography Angiography: a Systematic Review.

OBJECTIVE: To systematically investigate the literature for the influence of sublingual nitroglycerin administration on coronary diameter, the number of evaluable segments, image quality, heart rate and blood pressure, and diagnostic accuracy of coronary computed tomography (CT) angiography. METHODS: A systematic search was performed in PubMed, EMBASE and Web of Science. The studies were evaluated for the effect of sublingual nitroglycerin on coronary artery diameter, evaluable segments, objective and subjective image quality, systemic physiological effects and diagnostic accuracy. Due to the heterogeneous reporting of outcome measures, a narrative synthesis was applied. RESULTS: Of the 217 studies identified, nine met the inclusion criteria: seven reported on the effect of nitroglycerin on coronary artery diameter, six on evaluable segments, four on image quality, five on systemic physiological effects and two on diagnostic accuracy. Sublingual nitroglycerin administration resulted in an improved evaluation of more coronary segments, in particular, in smaller coronary branches, better image quality and improved diagnostic accuracy. Side effects were mild and were alleviated without medical intervention. CONCLUSION: Sublingual nitroglycerin improves the coronary diameter, the number of assessable segments, image quality and diagnostic accuracy of coronary CT angiography without major side effects or systemic physiological changes. KEY POINTS: • Sublingual nitroglycerin administration results in significant coronary artery dilatation. • Nitroglycerin increases the number of evaluable coronary branches. • Image quality is improved the most in smaller coronary branches. • Nitroglycerin increases the diagnostic accuracy of coronary CT angiography. • Most side effects are mild and do not require medical intervention.

Multidetector-row computed tomography for prosthetic heart valve dysfunction: is concomitant non-invasive coronary angiography possible before redo-surgery?

OBJECTIVES: Retrospective ECG-gated multidetector-row computed tomography (MDCT) is increasingly used for the assessment of prosthetic heart valve (PHV) dysfunction, but is also hampered by PHV-related artefacts/cardiac arrhythmias. Furthermore, it is performed without nitroglycerine or heart rate correction. The purpose was to determine whether MDCT performed before potential redo-PHV surgery is feasible for concomitant coronary artery stenosis assessment and can replace invasive coronary angiography (CAG). METHODS: PHV patients with CAG and MDCT were identified. Based on medical history, two groups were created: (I) patients with no known coronary artery disease (CAD), (II) patients with known CAD. All images were scored for the presence of significant (>50 %) stenosis. CAG was the reference test. RESULTS: Fifty-one patients were included. In group I (n = 38), MDCT accurately ruled out significant stenosis in 19/38 (50 %) patients, but could not replace CAG in the remaining 19/38 (50 %) patients due to non-diagnostic image quality (n = 16) or significant stenosis (n = 3) detection. In group II (n = 13), MDCT correctly found no patients without significant stenosis, requiring CAG imaging in all. MDCT assessed patency in 16/19 (84 %) grafts and detected a hostile anatomy in two. CONCLUSION: MDCT performed for PHV dysfunction assessment can replace CAG (100 % accurate) in approximately half of patients without previously known CAD. KEY POINTS: • Retrospective MDCT is increasingly used for prosthetic heart valve dysfunction assessment • In case of PHV reoperation, invasive coronary angiography is also required • MDCT can replace CAG in 50 % of patients without coronary artery disease • When conclusive for coronary assessment, MDCT stenosis rule out is highly accurate • Replacing CAG saves associated risks of distant embolization of thrombi or vegetations.

Multidetector-row computed tomography allows accurate measurement of mechanical prosthetic heart valve leaflet closing angles compared with fluoroscopy.

PURPOSE: The purpose of this study was to compare multidetector-row computed tomography (MDCT) leaflet restriction measurements with fluoroscopy measurements in commonly used mechanical prosthetic heart valves (PHVs). METHODS: Four mechanical PHVs (ON-X, Carbomedics, St. Jude, and Medtronic Hall) were imaged in a pulsatile model using fluoroscopy and 64-detector-row computed tomography. Five image acquisitions of each PHV without (1) and with (4) restricted leaflet closure were made. Three observers measured closure angles on fluoroscopy and MDCT. Data were analyzed using intraclass correlation coefficient (ICC) and Bland-Altman plots. RESULTS: Interobserver agreement was high in restricted and non-restricted leaflets on both modalities (ICCs >0.995). MDCT and fluoroscopy showed high agreements (ICCs >0.989). Median MDCT closure angle measurements differed at most -2 to +2 degrees from fluoroscopy in the restricted and -1 to +2 degrees in the non-restricted leaflets. CONCLUSIONS: MDCT allows measurement of leaflet motion with a maximal median discrepancy of 2 degrees. Both MDCT and fluoroscopy detect restricted leaflet closure with great accuracy.