Computational framework for the generation of one-dimensional vascular models accounting for uncertainty in networks extracted from medical images.

One-dimensional (1D) cardiovascular models offer a non-invasive method to answer medical questions, including predictions of wave-reflection, shear stress, functional flow reserve, vascular resistance and compliance. This model type can predict patient-specific outcomes by solving 1D fluid dynamics equations in geometric networks extracted from medical images. However, the inherent uncertainty in in vivo imaging introduces variability in network size and vessel dimensions, affecting haemodynamic predictions. Understanding the influence of variation in image-derived properties is essential to assess the fidelity of model predictions. Numerous programs exist to render three-dimensional surfaces and construct vessel centrelines. Still, there is no exact way to generate vascular trees from the centrelines while accounting for uncertainty in data. This study introduces an innovative framework employing statistical change point analysis to generate labelled trees that encode vessel dimensions and their associated uncertainty from medical images. To test this framework, we explore the impact of uncertainty in 1D haemodynamic predictions in a systemic and pulmonary arterial network. Simulations explore haemodynamic variations resulting from changes in vessel dimensions and segmentation; the latter is achieved by analysing multiple segmentations of the same images. Results demonstrate the importance of accurately defining vessel radii and lengths when generating high-fidelity patient-specific haemodynamics models. KEY POINTS: This study introduces novel algorithms for generating labelled directed trees from medical images, focusing on accurate junction node placement and radius extraction using change points to provide haemodynamic predictions with uncertainty within expected measurement error. Geometric features, such as vessel dimension (length and radius) and network size, significantly impact pressure and flow predictions in both pulmonary and aortic arterial networks. Standardizing networks to a consistent number of vessels is crucial for meaningful comparisons and decreases haemodynamic uncertainty. Change points are valuable to understanding structural transitions in vascular data, providing an automated and efficient way to detect shifts in vessel characteristics and ensure reliable extraction of representative vessel radii.

Diagnosis of acute pulmonary embolism: when photon-counting-detector CT replaces energy-integrating-detector CT in daily routine.

PURPOSE: To compare the diagnostic approach of acute pulmonary embolism (PE) with photon-counting-detector CT (PCD-CT) and energy-integrating-detector CT (EID-CT). MATERIALS AND METHODS: Two cohorts underwent CT angiographic examinations with EID-CT (Group 1; n = 158) and PCD-CT (Group 2; n = 172), (b) with two options in Group 1, dual energy (Group 1a) or single energy (Group 1b) and a single option in Group 2 (spectral imaging with single source). RESULTS: In Group 2, all patients benefited from spectral imaging, only accessible to 105 patients (66.5%) in Group 1, with a mean acquisition time significantly shorter (0.9 ± 0.1 s vs 4.0 ± 0 .3 s; p < 0.001) and mean values of CTDIvol and DLP reduced by 46.3% and 47.7%, respectively. Comparing the quality of 70 keV (Group 2) and averaged (Group 1a) images: (a) the mean attenuation within pulmonary arteries did not differ (p = 0.13); (b) the image noise was significantly higher (p < 0.001) in Group 2 with no difference in subjective image noise (p = 0.29); and (c) 89% of examinations were devoid of artifacts in Group 2 vs 28.6% in Group 1a. The percentage of diagnostic examinations was 95.2% (100/105; Group 1a), 100% (53/53; Group 1b), and 95.3% (164/172; Group 2). There were 4.8% (5/105; Group 1a) and 4.7% (8/172; Group 2) of non-diagnostic examinations, mainly due to the suboptimal quality of vascular opacification with the restoration of a diagnostic image quality on low-energy images. CONCLUSION: Compared to EID-CT, morphology and perfusion imaging were available in all patients scanned with PCD-CT, with the radiation dose reduced by 48%. CLINICAL RELEVANCE STATEMENT: PCD-CT enables scanning patients with the advantages of both spectral imaging, including high-quality morphologic imaging and lung perfusion for all patients, and fast scanning-a combination that is not simultaneously accessible with EID-CT while reducing the radiation dose by almost 50%.

Thrombus or tumor? A case report of a rare sarcoma entity: intimal sarcoma of the pulmonary arteries.

BACKGROUND: Tumor embolism is a very rare primary manifestation of cancers and the diagnosis is challenging, especially if located in the pulmonary arteries, where it can mimic nonmalignant pulmonary embolism. Intimal sarcoma is one of the least commonly reported primary tumors of vessels with only a few cases reported worldwide. A typical location of this malignancy is the pulmonary artery. Herein, we present a case report of an intimal sarcoma with primary manifestation in the pulmonary arteries. A 53-year-old male initially presented with dyspnea. On imaging, a pulmonary artery embolism was detected and was followed by thrombectomy of the right ventricular outflow tract, main pulmonary artery trunk, and right pulmonary artery after ineffective lysis therapy. Complementary imaging of the chest and abdomen including a PET-CT scan demonstrated no evidence of a primary tumor. Subsequent pathology assessment suggested an intimal sarcoma further confirmed by DNA methylation based molecular analysis. We initiated adjuvant chemotherapy with doxorubicin. Four months after the completion of adjuvant therapy a follow-up scan revealed a local recurrence without distant metastases. DISCUSSION: Primary pulmonary artery intimal sarcoma (PAS) is an exceedingly rare entity and pathological diagnosis remains challenging. Therefore, the detection of entity-specific molecular alterations is a supporting argument in the diagnostic spectrum. Complete surgical resection is the prognostically most important treatment for intimal cardiac sarcomas. Despite adjuvant chemotherapy, the prognosis of cardiac sarcomas remains very poor. This case of a PAS highlights the difficulty in establishing a diagnosis and the aggressive natural course of the disease. CONCLUSION: In case of atypical presentation of a pulmonary embolism, a tumor originating from the great vessels should be considered. Molecular pathology techniques support in establishing a reliable diagnosis.

Bilateral ductal stenting in an infant with pulmonary atresia and ventricular septal defect, non-confluent pulmonary arteries, and bilateral arterial duct.

Pulmonary atresia with ventricular septal defect, non-confluent pulmonary arteries, and bilateral arterial duct is a rare and complex CHD. Physiologic ductal closure may lead to life-threatening hypoxia. We present a case of successful bilateral ductal stenting as a bridge to further lower-risk surgical repair.

Prenatal Diagnosis of Crossed Pulmonary Arteries with a Postnatal Diagnosis of CHARGE Syndrome.

Introduction: Crossed pulmonary arteries (CPA) is an abnormality in which the ostium of the left pulmonary artery is located rightward and the ostium of the right pulmonary artery is leftward. Case report: We diagnosed a fetus with CPA prenatally. In fetal echocardiography, left pulmonary artery was seen to pass beneath the ductus and directing toward the left side and pulmonary artery bifurcation could not be demonstrated at the same plane. Postnatal echocardiography reconfirmed the presence of CPA. Bilateral choanal atresia, genital hypoplasia, hearing loss with facial and external ear asymmetry and psychomotor delay of the newborn led to clinical diagnosis of CHARGE syndrome and was confirmed by gene analysis. Discussion/Conclusion: CPA may be one of the cardiac anomalies in CHARGE syndrome.

Right ventricular failure in pulmonary hypertension: recent insights from experimental models.

Right ventricular (RV) function is a critical determinant of the prognosis of patients with pulmonary hypertension (PH). Upon establishment of PH, RV dysfunction develops, leading to a gradual worsening of the condition over time, culminating in RV failure and premature mortality. Despite this understanding, the underlying mechanisms of RV failure remain obscure. As a result, there are currently no approved therapies specifically targeting the right ventricle. One contributing factor to the lack of RV-directed therapies is the complexity of the pathogenesis of RV failure as observed in animal models and clinical studies. In recent years, various research groups have begun utilizing multiple models, including both afterload-dependent and afterload-independent models, to investigate specific targets and pharmacological agents in RV failure. In this review, we examine various animal models of RV failure and the recent advancements made utilizing these models to study the mechanisms of RV failure and the potential efficacy of therapeutic interventions, with the ultimate goal of translating these findings into clinical practice to enhance the management of individuals with PH.

Computed tomography and magnetic resonance imaging for pulmonary embolus evaluation in children: up-to-date review on practical imaging protocols.

Pulmonary embolism (PE) is a potentially life-threatening condition that requires immediate medical intervention. Although PE was previously thought to occur infrequently in the pediatric population, recent studies have found a higher-than-expected prevalence of PE in the pediatric population of up to 15.5%. The imaging modality of choice for detecting PE in the pediatric population is multi-detector CT angiography, although MRI is assuming a growing and more important role as a potential alternative modality. Given the recent advances in both computed tomography pulmonary angiography (CTPA) and MRI techniques, a growing population of pediatric patients with complex comorbidities (such as children with a history of surgeries for congenital heart disease repair), and the recent waves of coronavirus disease 2019 (COVID-19) and multisystem inflammatory syndrome in children (MIS-C), which are associated with increased risk of PE, there is new and increased need for an up-to-date review of practical CT and MRI protocols for PE evaluation in children. This article provides guidance for up-to-date CT and MR imaging techniques, reviews key recent studies on the imaging of pediatric PE, and discusses relevant pediatric PE imaging pearls and pitfalls, in hopes of providing readers with up-to-date and accurate practice for imaging evaluation of PE in children.

Risk Factors and Outcome of Pulmonary Artery Stenting After Bidirectional Cavopulmonary Connection (BDCPC) in Single Ventricle Circulation.

After bidirectional cavopulmonary connection (BDCPC) central pulmonary arteries (PAs) of single ventricle (SV) patients can be affected by stenosis or even closure. Aim of this study is to compare SV patients with and without PA-stent implantation post-BDCPC regarding risk factors for stent implantation and outcome. Single center, retrospective (2006-2021) study of 136 SV consecutive patients with and without PA-stent implantation post-BDCPC. Patient characteristics, risk factors for PA-stent implantation and PA growth were assessed comparing angiographic data pre-BDCPC and pre-TCPC. A total of 40/136 (29%) patients underwent PA-stent implantation at median (IQR) 14 (1.1-39.0) days post-BDCPC. 37/40 (92.5%) underwent LPA-stenting. Multiple regression analysis showed single LV patients to receive less likely PA-stents than single RV patients (OR 0.41; p = 0.05). Reduced LPA/BSA (mm/m2) and larger diameter of neo-ascending aorta pre-BDCPC were associated with an increased likelihood of PA-stent implantation post-BDCPC (OR 0.89, p = 0.03; OR 1.05, p = 0.001). Stent re-dilatation was performed in 36/40 (89%) after 1 (0.8-1.5) year. Pulmonary artery diameters pre-BDCPC were lower in the PA-stent group: McGoon (p < 0.001), Nakata (p < 0.001). Indexed pulmonary artery diameters increased equally in both groups but remained lower pre-TCPC in the PA-stent group: McGoon (p < 0.001), Nakata (p = 0.009), and Lower Lobe Index (p = 0.003). LPA and RPA grew symmetrically in both groups. Single RV, larger neo-ascending aorta, and small LPA pre- BDCPC are independent risk factors for PA-stent implantation post-BDCPC. Pulmonary artery diameters after PA-stent implantation and stent re-dilatation showed significant growth together with the contralateral side, but the PA-system remained symmetrically smaller in the stent group.

Cross my heart: ventriculoatrial shunt migration into the pulmonary arteries.

We present here a rare complication of ventriculoatrial shunt: migration of the distal catheter into both pulmonary arteries. The patient showed no cardiorespiratory symptoms. The catheter was removed by endovascular technic, the most usual procedure in these cases.

Crossed pulmonary arteries: An underestimated cardiovascular variant with a strong association with genetic syndromes-A report of 74 cases with systematic review of the literature.

Crossed pulmonary arteries (CPAs) represent an uncommon anatomic variant, usually associated with some specific syndromes and conotruncal defects. This finding has been described in 22q11.2 Deletion Syndrome (22q11.2DS). We evaluated the correlation between CPAs and genetic diseases, in order to better define the characteristics of this variant, considered a rare anatomic pattern. An in-depth analysis of CPAs genotype-phenotype correlations was performed via a literature review. We detected 74 CPAs patients through echocardiography. Of these 74 patients, 35.1% of patients showed additional intracardiac malformations, while 29.7% showed extracardiac vascular anomalies, of which 16.2% were associated with intracardiac defects and 13.5% were not. In all, 62.2% of patients were diagnosed with genetic diseases and 52.2% of them were 22q11.2DS patients. In conclusions, CPAs represent a cardiovascular variant, which is detectable in nonsyndromic individuals, but especially in various genetic syndromes and in particular in 22q11.2DS patients. Data on the real prevalence of this morphology is lacking in literature. Knowledge of this anatomic variant is useful to interpret the unusual course of the pulmonary branches and is helpful information before cardiovascular surgical correction. Moreover, due to the strong association of CPAs with some genetic syndromes, the identification of this anatomic pattern can indicate the utility of a genetic assessment of these patients.

Computed tomography and magnetic resonance imaging of vascular rings and other things: a pictorial review.

Compression of the airway, esophagus or both by aortic and pulmonary vessels can be caused by a variety of anatomical situations. Vascular rings are the most commonly encountered entity; however, compression can also occur from less common anomalies such as a left pulmonary artery sling or innominate artery compression. Vascular rings and other vascular compression abnormalities can be challenging to visualize and image and often require advanced imaging by CT or MRI to better understand the cause and extent of compression. Atretic vascular structures, such as the ligamentum arteriosum or atretic arch, play a key role in creating a vascular ring and do not enhance with contrast agent in a typical fashion. Despite these imaging challenges, classic and useful signs can indicate the presence or absence of a vascular ring or compression.

Evaluation of cardiovascular morphology and associated anomalies in patients with crossed pulmonary arteries on multidetector computed tomography angiography.

AIM: The present study sought to study morphology and associated cardiovascular anomalies in patients with crossed pulmonary arteries on multidetector computed tomography (CT) angiography. MATERIALS AND METHODS: We retrospectively evaluated all CT angiography studies performed at a tertiary medical center from January 2014 to December 2021 to identify patients with crossed pulmonary arteries. The associated cardiovascular anomalies as identified on CT angiography were evaluated. RESULTS: Out of 4773 patients who had undergone CT angiography for evaluation of congenital heart diseases, we identified 24 (0.5%) patients (18 males; mean age: 7.7 years) with crossed pulmonary arteries. Tetralogy of Fallot was associated in seven (29.17%) patients, double outlet right ventricle in one (4.17%) patient, and common arterial trunk in four (16.67%) patients. An aortopulmonary window was seen in three (12.5%) patients while atrial septal defect and ventricular septal defect were seen in two (8.33%) and 16 (66.67%) patients, respectively. Aortic arch anomalies were present in 16 (66.67%) patients including interrupted aortic arch and coarctation of aorta with hypoplastic aortic arch seen in two (8.33%) patients each. A double aortic arch with an atretic left arch was seen in one (4.17%) patient. Coronary artery anomalies were seen in three (12.5%) patients. CONCLUSION: Crossed pulmonary arteries are a rare anomaly and their presence suggests the coexistence of a variety of cardiovascular anomalies, including aortic arch anomalies and outflow tract malformations. Comprehensive CT angiography-based evaluation of cardiovascular morphology is imperative in the presence of crossed pulmonary arteries to facilitate presurgical planning.

A neonate with crossed pulmonary arteries: a case report and literature review of 115 cases worldwide.

Malposition of the branch pulmonary arteries (MBPA) is an unusual malformation characterised by anomalous origin of both pulmonary arteries from the main pulmonary trunk. To date, only few cases have been reported. Herein, we present the first case report of a 3-day-old, full-term male neonate with the lesser form of crossed pulmonary arteries in Saudi Arabia detected by echocardiography and confirmed by cardiac CT. Crossed pulmonary arteries is not a rare anomaly, but it is a somewhat underreported anomaly, and their recognition is important because it is usually associated with other CHDs, airway obstruction, extra-cardiac anomalies, and certain genetic syndromes.

Crossed pulmonary arteries and DiGeorge syndrome: case reports and literature review.

DiGeorge syndrome has heterogeneous clinical presentation, and for this reason, its diagnosis can be challenging and may be missed. Since CHDs are very common in this patients, they can be considered pillars of clinical diagnosis of the syndrome. Therefore, accurate echocardiography is needed to detect even minor cardiac anomalies, as some specific malformation like crossed pulmonary arteries can be associated with 22q11 syndrome. We report two cases of newborns where the diagnosis of DiGeorge syndrome was suspected after finding crossed pulmonary arteries on echocardiography. In order to reach a timely diagnosis of DiGeorge syndrome, we suggest a careful echocardiographic examination of the pulmonary arteries position in all patients and genetic analysis for 22q11.2 microdeletion in patients in whom malposition has been detected.

Very preterm and very low birthweight infant with pulmonary atresia intact ventricular septum, right ventricle-dependent coronary circulation, and discontinuous pulmonary arteries.

Prematurity and low birthweight are associated with increased mortality in infants undergoing cardiac surgery. Pulmonary atresia with intact ventricular septum and right ventricle-dependent coronary circulation carries one of the highest risks of mortality. We present a patient who was born at 28 weeks of gestation at 1.2 kg, with pulmonary atresia intact ventricular septum, right ventricle-dependent coronary circulation, coronary artery atresia, and discontinuous pulmonary arteries, who successfully underwent palliation with a modified Blalock-Taussig shunt, pulmonary arterioplasty, and subsequently a bidirectional Glenn.

Overview of Cardiopulmonary Bypass Techniques and the Incidence of Postoperative Complications in Pediatric Patients Undergoing Complex Pulmonary Artery Reconstruction.

Cardiopulmonary bypass (CPB) is routinely used for performing congenital heart operations. While most congenital heart operations can be performed with bypass times under 2 hours, complex pulmonary artery reconstructions require longer periods of CPB to facilitate the surgical repair. This article is intended to summarize the surgical and perfusion techniques utilized in patients undergoing complex pulmonary artery reconstructions at our institution. The initial portion of this manuscript provides an in-depth description of the surgical techniques employed for pulmonary artery reconstructions. This information is important in order to understand why prolonged CPB is a necessary requirement. The manuscript then provides a detailed description of the perfusion techniques and the modifications to the CPB circuit. Finally, the manuscript provides a summary of data from a clinical study evaluating the application of these techniques in 100 consecutive children undergoing complex pulmonary artery reconstruction. The data from this study demonstrated that there was a poor correlation between duration of CPB and both the number of postoperative complications and hospital length of stay. Major adverse cardiac events occurred in 11 (11%) patients with one hospital mortality. These results suggest that prolonged CPB does not predispose to adverse outcomes in this select population of patients.

[Chronic thromboembolic pulmonary hypertension: from pathogenesis to the choice of treatment tactics].

Presents data on the pathogenesis of chronic thromboembolic pulmonary hypertension (CTEPH), which serve as a rationale for approaches to the choice of treatment. CTEPH usually begins with persistent obstruction of the large and/or medium pulmonary arteries by organized thrombi. Impaired lysis of thrombi may be associated with abnormal fibrinolysis, hematological or autoimmune diseases. The molecular processes underlying the lesions of small vessels are not fully understand. The degree of small-vessel disease has a significant impact on the severity of CTEPH and postoperative outcomes. The CTEPH treatment has evolved with the development of three directions pulmonary endarterectomy, balloon angioplasty of pulmonary arteries and the use of specific therapy used for pulmonary arterial hypertension. The paper demonstrates the possibilities of a multimodal approach in the treatment of this category of patients.

Cystamine Treatment Fails to Prevent the Development of Pulmonary Hypertension in Chronic Hypoxic Rats.

INTRODUCTION: Pulmonary hypertension is characterized by vasoconstriction and remodeling of pulmonary arteries, leading to right ventricular hypertrophy and failure. We have previously found upregulation of transglutaminase 2 (TG2) in the right ventricle of chronic hypoxic rats. The hypothesis of the present study was that treatment with the transglutaminase inhibitor, cystamine, would inhibit the development of pulmonary arterial remodeling, pulmonary hypertension, and right ventricular hypertrophy. METHODS: Effect of cystamine on transamidase activity was investigated in tissue homogenates. Wistar rats were exposed to chronic hypoxia and treated with vehicle, cystamine (40 mg/kg/day in mini-osmotic pumps), sildenafil (25 mg/kg/day), or the combination for 2 weeks. RESULTS: Cystamine concentration-dependently inhibited TG2 transamidase activity in liver and lung homogenates. In contrast to cystamine, sildenafil reduced right ventricular systolic pressure and hypertrophy and decreased pulmonary vascular resistance and muscularization in chronic hypoxic rats. Fibrosis in the lung tissue decreased in chronic hypoxic rats treated with cystamine. TG2 expression was similar in the right ventricle and lung tissue of drug and vehicle-treated hypoxic rats. DISCUSSION/CONCLUSIONS: Cystamine inhibited TG2 transamidase activity, but cystamine failed to prevent pulmonary hypertension, right ventricular hypertrophy, and pulmonary arterial muscularization in the chronic hypoxic rat.

Reference Values for Ventricular Volumes and Pulmonary Artery Dimensions in Pediatric Patients with Transposition of the Great Arteries After Arterial Switch Operation.

BACKGROUND: Pulmonary artery (PA) anatomy in patients with transposition of the great arteries (TGA) after arterial switch operation (ASO) with Lecompte manoeuvre is different compared to healthy subjects, and stenoses of the PA are common. Magnetic resonance imaging (MRI) is an excellent imaging modality to assess PA anatomy in TGA patients. However, disease-specific reference values for PA size are scarce. PURPOSE: To establish disease-specific reference ranges for PA dimensions and for biventricular volumes and mass. STUDY TYPE: Retrospective. SUBJECTS: A total of 69 pediatric patients with TGA after ASO (median age 12.6 years; range 5-17.8 years; 13 females and 56 males). FIELD STRENGTH/SEQUENCE: 3.0 T, steady-state free precession (SSFP) and gradient echo cine sequences and four-dimensional time-resolved magnetic resonance angiography with keyhole. ASSESSMENT: Right and left PA (RPA, LPA) were each measured at three locations during its course around the aorta. Ventricular volumes, mass, and ejection fraction were measured from a stack of short axis cine images. STATISTICAL TESTS: The lambda-mu-sigma (LMS) method of Cole and Green, univariate and multivariate linear models, and t-test. RESULTS: Centile graphs and tables for PA dimensions, biventricular volumes, mass, and ejection fraction were created. Univariate linear analysis showed significant associations (P < 0.05) between body surface area (BSA), height, and weight with systolic MPA and RPA diameter. In multivariate linear analysis, only BSA remained a strong predictor for main PA and RPA diameters. For biventricular volumes, the univariate linear model revealed a strong influence of BSA, height, weight, and age (all P < 0.05). On multivariate linear analysis, only body height remained associated. DATA CONCLUSION: Uni- and multivariate linear analyses showed a strong association between BSA and PA diameters, as well as between height and biventricular volumes, and therefore, centile tables and graphs are presented accordingly. Our data may improve MR image interpretation and may serve as a reference in future studies. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY STAGE: 2.

Prostanoid receptor subtypes involved in treprostinil-mediated vasodilation of rat pulmonary arteries and in treprostinil-mediated inhibition of collagen gene expression of human lung fibroblasts.

Treprostinil (TRE) is a potent pulmonary vasodilator with effects on other pathological aspects of pulmonary arterial hypertension. In this study, the prostanoid receptors involved in TRE-induced relaxation of isolated rat pulmonary arteries and TRE-induced inhibition of increased gene expression in collagen synthesis and contractility of human lung fibroblasts were determined. TRE (0.01-100 µM) relaxed prostaglandin F2α-precontracted rat pulmonary arteries which was attenuated by denudation of the vascular endothelium. TRE-induced relaxation was predominantly blocked by the IP receptor antagonist RO3244194 (1 µM), with slightly greater inhibition in endothelium-denuded tissue. At higher TRE concentrations (> 1 µM), the DP1 receptor antagonist BW A868C (1 µM) also inhibited relaxation reaching significance above 10 µM. In contrast, the EP3 receptor antagonist L798106 (1 µM) accentuated TRE-induced relaxation of pulmonary arteries with intact endothelium. In human lung fibroblasts, the EP2 receptor antagonist PF-04418948 (1 µM) blocked transforming growth factor ß1 (TGF-ß1)-increased expression of collagen synthesis (COL1A1 and COL1A2) and fibroblast contractility (ACTG2) genes in presence of TRE (0.1 µM). In conclusion, the IP receptor located on rat pulmonary vascular smooth muscle and endothelium is the primary receptor mediating vasorelaxation, while the DP1 receptor present on the rat endothelium is involved only at higher TRE concentrations. In human lung fibroblasts, the EP2 receptor is the dominant receptor subtype involved in suppression of increased collagen synthesis and fibroblast contractility gene expression induced by TGF-ß1 in the presence of TRE.