State of the art: iterative CT reconstruction techniques

Owing to recent advances in computing power, iterative reconstruction (IR) algorithms have become a clinically viable option in computed tomographic (CT) imaging. Substantial evidence is accumulating about the advantages of IR algorithms over established analytical methods, such as filtered back projection. IR improves image quality through cyclic image processing. Although all available solutions share the common mechanism of artifact reduction and/or potential for radiation dose savings, chiefly due to image noise suppression, the magnitude of these effects depends on the specific IR algorithm. In the first section of this contribution, the technical bases of IR are briefly reviewed and the currently available algorithms released by the major CT manufacturers are described. In the second part, the current status of their clinical implementation is surveyed. Regardless of the applied IR algorithm, the available evidence attests to the substantial potential of IR algorithms for overcoming traditional limitations in CT imaging

Dual energy imaging and intracycle motion correction for CT coronary angiography in patients with intermediate to high likelihood of coronary artery disease

We explored whether intracycle motion correction algorithms (MCAs) might be applicable to dual energy computed tomography coronary angiography in patients with intermediate to high likelihood of coronary artery disease. MCA reconstructions were associated with higher interpretability rates (96.7% vs 87.9%, P < .001), image quality scores (4.12±0.9 vs. 3.76±1.0; P < .0001), and diagnostic performance [area under the curve of 0.95 (95% confidence interval [CI] 0.92-0.97) vs 0.89 (95% CI 0.86-0.92); P < .0001] compared to conventional reconstructions. In conclusion, application of intracycle MCA reconstructions to dual energy computed tomography acquisitions was feasible and resulted in significantly higher image quality scores, interpretability, and diagnostic performance.Fil: Carrascosa, Patricia. Diagnóstico Maipú; ArgentinaFil: Deviggiano, Alejandro. Diagnóstico Maipú; ArgentinaFil: Leipsic, Jonathon A.. St. Paul's Hospital; CanadáFil: Capunay, Carlos. Diagnóstico Maipú; ArgentinaFil: De Zan, Macarena C.. Diagnóstico Maipú; ArgentinaFil: Goldsmit, Alejandro. Sanatorio Güemes; ArgentinaFil: Rodriguez Granillo, Gaston Alfredo. Diagnóstico Maipú; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; Argentin

Free-breathing Pulmonary (1)H and Hyperpolarized (3)He MRI: Comparison in COPD and Bronchiectasis.

RATIONALE AND OBJECTIVES: In this proof-of-concept demonstration, we aimed to quantitatively and qualitatively compare pulmonary ventilation abnormalities derived from Fourier decomposition of free-breathing (1)H magnetic resonance imaging (FDMRI) to hyperpolarized (3)He MRI in subjects with chronic obstructive pulmonary disease (COPD) and bronchiectasis. MATERIALS AND METHODS: All subjects provided written informed consent to a protocol approved by a local research ethics board and Health, Canada, and they underwent MRI, computed tomography (CT), spirometry, and plethysmography during a single 2-hour visit. Semiautomated segmentation was used to generate ventilation defect measurements derived from FDMRI and (3)He MRI, and these were compared using analysis of variance and Pearson correlations. RESULTS: Twenty-six subjects were evaluated including 12 COPD subjects (67 ± 9 years) and 14 bronchiectasis subjects (70 ± 11 years). For COPD subjects, FDMRI and (3)He MRI ventilation defect percent (VDP) was 7 ± 6% and 24 ± 14%, respectively (P \u3c .001; bias = -16 ± 9%). In COPD subjects, FDMRI was significantly correlated with (3)He MRI VDP (r = .88; P = .0001), (3)He MRI apparent diffusion coefficient (r = .71; P \u3c .05), airways resistance (r = .60; P \u3c .05), and RA950 (r = .80; P \u3c .01). In subjects with bronchiectasis, FDMRI VDP (5 ± 3%) and (3)He MRI VDP (18 ± 9%) were significantly different (P \u3c .001) and not correlated (P \u3e .05). The Dice similarity coefficient (DSC) for FDMRI and (3)He MRI ventilation was 86 ± 7% for COPD and 86 ± 4% for bronchiectasis subjects (P \u3e .05); the DSC for FDMRI ventilation defects and CT RA950 was 19 ± 20% in COPD and 2 ± 3% in bronchiectasis subjects (P \u3c .01). CONCLUSIONS: FDMRI and (3)He MRI VDP were strongly related in COPD but not in bronchiectasis subjects. In COPD only, FDMRI ventilation defects were spatially related with (3)He ventilation defects and emphysema

Outcome of Patients After Transcatheter Aortic Valve Embolization

ObjectivesThis study aims to assess the mid- to long-term follow-up of patients after valve embolization at the time of transcatheter aortic valve implantation (TAVI).BackgroundTranscatheter heart valve (THV) embolization is a rare but serious complication during TAVI. Although various techniques have been developed to manage acute complications and reduce periprocedural morbidity/mortality, long-term clinical and hemodynamic consequences after these events are unknown.MethodsPatients who developed THV embolization after TAVI were prospectively assessed. Clinical and echocardiographic characteristics were recorded at baseline and after successful TAVI/surgical aortic valve replacement. The THV migration and strut fractures/degeneration were assessed by computed tomography.ResultsA total of 7 patients had THV embolization, all of which occurred immediately after valve deployment. The embolized THV was repositioned in the aortic arch proximal to the left subclavian artery (n = 2), immediately distal to the left subclavian artery (n = 2), and in the abdominal aorta (n = 3). A second THV was implanted successfully at the same sitting in 4 patients and at the time of a second procedure in 2 patients. Elective conventional aortic valve replacement was performed in 1 patient. Median follow-up was 1,085 days. One patient died during follow-up from an unrelated cause. The remaining 6 survivors were in New York Heart Association functional class I or II at final follow-up. Mid-term computed tomography follow-up (n = 4,591 to 1,548 days) showed that the leaflets of the embolized THV remain open in all phases of the cardiac cycle. There was also no strut fracture or migration of these valves.ConclusionsClinical outcomes remain good when THV embolization is managed effectively. There are no apparent hemodynamic consequences of a second valve placed in the series. These embolized valves remain in a stable position with no evidence of strut fractures at mid-term follow-up

Clinical Research on Transcatheter Aortic Valve Replacement for Bicuspid Aortic Valve Disease: Principles, Challenges, and an Agenda for the Future

Bicuspid aortic valve disease (BAVD) is present in up to half of all patients referred for surgical aortic valve replacement (SAVR) yet was an exclusion criterion for all randomized controlled trials (RCTs) comparing transcatheter aortic valve replacement (TAVR) to SAVR. Nonetheless, approximately 10% of patients currently treated with TAVR have BAVD and available observational data for performing TAVR in these patients are limited by selection bias. Many in the cardiovascular community have advocated for RCTs in this population, but none have been performed. The Heart Valve Collaboratory (HVC) is a multidisciplinary community of stakeholders with the aim of creating significant advances in valvular heart disease by stimulating clinical research, engaging in educational activities, and advancing regulatory science. In December 2020, the HVC hosted a Global Multidisciplinary workshop involving over 100 international experts in the field. Following this 2-day symposium, working groups with varied expertise were convened to discuss BAVD, including the need for and design of RCTs. This review, conducted under the auspices of the HVC, summarizes available data and knowledge gaps regarding procedural therapy for BAVD, outlining specific challenges for trials in this population. We also propose several potential studies that could be performed and discuss respective strengths and weaknesses of each approach. Finally, we present a roadmap for future directions in clinical research in TAVR for BAVD with an emphasis both on RCTs and also prospective registries focused on disease phenotyping to develop parameters and risk scores that could ultimately be applied to patients to inform clinical decision-making

Kedudukan Anak Akibat Batalnya Perkawinan Karena Hubungan Darah Menurut Hukum Positif

Penelitian ini dilakukan dengan tujuan untuk mengetahui bagaimana pengaturan hukum tentang Pembatalan Perkawinan karena hubungan darah menurut Hukum Positif Di Indonesia dan bagaimana kedudukan hukum anak yang lahir setelah pembatalan perkawinan menurut Hukum Positif di Indonesia. Dengan menggunakan metode penelitian yuridis normatif, maka dapat disimpulkan: 1. Pengaturan hukum mengenai pembatalan perkawinan di Indonesia masih beragam walaupun Undang-Undang perkawinan yaitu Undang-Undang Nomor 1 Tahun 1974 seringkali disebut unifikasi hukum perkawinan. Pembatalan perkawinan merupakan putusnya perkawinan disebabkan persyaratan perkawinan yang diatur dalam undang-undang dan larangan perkawinan tidak dipenuhi. 2. Status hukum anak yang lahir dalam perkawinan yang telah batal pada dasarnya merupakan anak yang sah sebagaimana diatur dalam Undang-Undang Nomor 1 Tahun 1974 dalam Pasal 28. Berdasarkan Putusan Mahkamah Konstitusi Nomor 46/PUU-VIII/2010 Tentang Pengujian pasal 2 ayat 2 dan pasal 43 ayat 1 Undang-Undang Perkawinan yaitu Undang-Undang Nomor 1 Tahun 1974 yang menyatakan bahwa pasal 43 ayat Undang-Undang Nomor 1 Tahun 1974 melanggar Undang-Undang Dasar Republik Indonesia pasal 28 B ayat 1 dan 2 dan pasal 28 D ayat 1

Ex vivo 18F-fluoride uptake and hydroxyapatite deposition in human coronary atherosclerosis

Early microcalcification is a feature of coronary plaques with an increased propensity to rupture and to cause acute coronary syndromes. In this ex vivo imaging study of coronary artery specimens, the non-invasive imaging radiotracer, 18F-fluoride, was highly selective for hydroxyapatite deposition in atherosclerotic coronary plaque. Specifically, coronary 18F-fluoride uptake had a high signal to noise ratio compared with surrounding myocardium that makes it feasible to identify coronary mineralisation activity. Areas of 18F-fluoride uptake are associated with osteopontin, an inflammation-associated glycophosphoprotein that mediates tissue mineralisation, and Runt-related transcription factor 2, a nuclear protein involved in osteoblastic differentiation. These results suggest that 18F-fluoride is a non-invasive imaging biomarker of active coronary atherosclerotic mineralisation

Transcatheter heart valve commissural alignment: an updated review

Transcatheter aortic valve replacement (TAVR) indications recently extended to lower surgical risk patients with longer life expectancy. Commissural alignment (CA) is one of the emerging concepts and is becoming one of the cornerstones of the TAVR procedure in a patient with increased longevity. Indeed, CA may improve transcatheter heart valve (THV) hemodynamics, future coronary access, and repeatability. The definition of CA has been recently standardized by the ALIGN-TAVR consortium using a four-tier scale based on CT analysis. Progress has been made during the index TAVR procedure to optimize CA, especially with self-expandable platforms. Indeed, specific delivery catheter orientation, THV rotation, and computed-tomography-derived views have been proposed to achieve a reasonable degree of CA. Recent data demonstrate feasibility, safety, and a significant reduction in coronary overlap using these techniques, especially with self-expandable platforms. This review provides an overview of THV CA including assessment methods, alignment techniques during the index TAVR procedure with different THV platforms, the clinical impact of commissural misalignment, and challenging situations for CA

MULTI-MODALITY IMAGING IN AORTIC STENOSIS:AN EACVI CLINICAL CONSENSUS DOCUMENT

International audienceIn this EACVI clinical scientific update, we will explore the current use of multi-modality imaging in the diagnosis, risk stratification, and follow-up of patients with aortic stenosis, with a particular focus on recent developments and future directions. Echocardiography is and will likely remain the key method of diagnosis and surveillance of aortic stenosis providing detailed assessments of valve haemodynamics and the cardiac remodelling response. Computed tomography (CT) is already widely used in the planning of transcutaneous aortic valve implantation. We anticipate its increased use as an anatomical adjudicator to clarify disease severity in patients with discordant echocardiographic measurements. CT calcium scoring is currently used for this purpose; however, contrast CT techniques are emerging that allow identification of both calcific and fibrotic valve thickening. Additionally, improved assessments of myocardial decompensation with echocardiography, cardiac magnetic resonance, and CT will become more commonplace in our routine assessment of aortic stenosis. Underpinning all of this will be widespread application of artificial intelligence. In combination, we believe this new era of multi-modality imaging in aortic stenosis will improve the diagnosis, follow-up, and timing of intervention in aortic stenosis as well as potentially accelerate the development of the novel pharmacological treatments required for this disease

Aortic Annulus Diameter Determination by Multidetector Computed Tomography Reproducibility, Applicability, and Implications for Transcatheter Aortic Valve Implantation

ObjectivesThis study sought to determine the most reproducible multidetector computed tomography (MDCT) measurements of the aortic annulus and to determine methods to improve the applicability of these measurements for transcatheter aortic valve implantation.BackgroundThe reproducibility and applicability of MDCT annular measurements to guide transcatheter aortic valve implantation remain unclear.MethodsAnnular measurements were performed in 50 patients planed for transcatheter aortic valve implantation in multiple planes: basal ring (short- and long-axis, mean diameter, area-derived diameter), coronal, sagittal, and 3-chamber projections. A theoretical model was developed taking into account the differences between the most reproducible MDCT measurements and transesophageal echocardiography to guide valve size choice.ResultsThe most reproducible measurements were the area-derived diameter and basal ring average diameter (inter-reader intraclass correlation coefficient: 0.87 [95% confidence interval: 0.81 to 0.92] and 0.80 [95% confidence interval: 0.70 to 0.87]; respectively; intrareader >0.90 for all readers). These were generally larger than transesophageal echocardiography diameters (mean difference of 1.5 ± 1.6 mm and 1.1 ± 1.7 mm, respectively). When a strategy of valve-sizing is undertaken using these CT measurements using an echocardiographic sizing scale, a different THV size would be selected in 44% and 40% of cases, respectively. When adjusting the sizing cutoffs to account for the differences in observed diameters, this was reduced to 10% to 12% (p < 0.01 for both, respectively).ConclusionsThe most reproducible MDCT measurements of the annulus are the area-derived diameter and basal ring average diameter, with derived values generally larger than those obtained with echocardiography. If MDCT is used for valve sizing, a strategy incorporating these differences may be important. MDCT using these easily derived measurements may be ideally suited to sizing transcatheter aortic valves as they account for the eccentricity of the aortic annulus, are reproducible, and are noninvasive