Search Results (365)

Time-of-flight magnetic resonance angiography (TOF-MRA) is widely used for noninvasive visualization of arterial anatomy, but extracting hemodynamics like blood velocity typically requires supplementary phase-contrast scans, tagging or multi-TE images. This study proposes a novel, physics-informed computational framework to extract variable fluid velocity directly from standard TOF-MRA signal profiles. We analytically expand the approach-to-steady-state Bloch equations to include convective flow, establishing a mathematical relationship between the spatial decay of longitudinal magnetization and fluid velocity. The velocity derivation was further extended to pointwise estimation over a 1-D centerline, overcoming the limitations of constant-velocity assumptions. To validate and solve this problem, a MATLAB (R2025b) simulation framework was developed to model fluid flow in two variable-geometry flowing tube cases, i.e., continuous narrowing and focal stenosis, under synthetic scanner noise. A global inverse optimization approach utilizing Dual-Tikhonov regularization was applied to stably invert the ill-posed transit time integral, actively penalizing high-frequency numerical ringing while preserving structural curves. The computational simulations successfully recovered ground-truth point-wise velocities, tracking gradual hemodynamic accelerations and sharp stenotic jets. This theoretical framework and the example centerline TOF-MRA signal intensity provide a robust mathematical proof-of-concept that quantitative, localized functional hemodynamic metrics can be extracted from standard structural MRA imaging, establishing a foundation for advanced flow quantification without requiring additional scan time. Full article

Kounis syndrome (KS) is a largely underdiagnosed cause of acute coronary syndromes triggered by allergic or hypersensitivity reactions. The syndrome results from complex immune cell activation with the release of vasoactive and prothrombotic mediators leading to coronary vasospasm (type I KS) or thrombosis of plaque (type II KS), stent (type III KS) or coronary artery bypass graft (type IV KS). Despite increasing recognition over the past few decades, its pathophysiological mechanisms, diagnostic boundaries, and therapeutic implications remain incompletely understood. A comprehensive diagnostic approach, including signs, symptoms, biochemical findings, electrocardiography, echocardiography, coronary angiography, and multimodality imaging, as well as invasive assessment in selected cases, can be recommended, although its implementation in routine practice remains limited. Available data indicate that angiographically documented epicardial coronary spasm is observed in only a minority of patients, while normal or non-obstructive coronary arteries are frequently encountered. Emerging data from provocative testing, invasive coronary functional assessment, cardiac magnetic resonance and nuclear imaging suggests that coronary microvascular dysfunction may contribute substantially to the clinical phenotype, expanding the traditional concept of allergic epicardial vasospasm. Current evidence supports the recognition of type I KS as a distinct allergic vasomotor acute coronary syndrome within the myocardial infarction non-obstructive coronary artery (MINOCA) spectrum, deserving greater recognition in future diagnostic classifications and clinical practice guidelines. This narrative review critically appraises current evidence, integrating historical perspectives with contemporary insights into classification, pathophysiology, triggers, diagnostic strategies and therapeutic approaches, focusing on the most frequent manifestation represented by the vasospastic variant. Full article

Background/Objectives: This study aimed to explore whether perioperative changes in cognitive function following carotid artery revascularization, including carotid endarterectomy (CEA) and carotid artery stenting (CAS), are associated with subsequent clinical outcomes, focusing specifically on the Standard Verbal Paired Associate Learning Test (S-PA). Methods: This prospective, single-center study enrolled 69 patients who underwent CEA or CAS between June 2018 and June 2024. Neuropsychological assessments (Raven’s Colored Progressive Matrices (RCPM), Kohs Block Design Test for IQ (Kohs-IQ), the Trail Making Test (TMT)-A/B, and the Standard Verbal Paired Associate Learning Test (S-PA)) were conducted preoperatively and within seven days postoperatively. Patient characteristics and diagnostic imaging results, including magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), and single-photon emission computed tomography (SPECT), were evaluated. Multivariate Cox proportional hazards models and Kaplan–Meier survival analyses were used to identify predictors of adverse outcomes, defined as recurrent stroke, restenosis, or mortality, during outpatient follow-up. Results: Fifteen patients experienced adverse outcomes during follow-up. Perioperative neuropsychological assessment showed that 36 patients experienced S-PA decline, indicating a tendency towards lower mean cerebral blood flow. Receiver operating characteristic (ROC) curve for perioperative ΔS-PA decline associated with adverse outcomes. The area under the curve (AUC) was 0.728. The optimal cutoff determined by the Youden index was a decline of 2 points (ΔS-PA ≤ −2), yielding a sensitivity of 73.3% and specificity of 68.5%. In a time-to-event analysis, S-PA decline was associated with adverse outcomes in an unadjusted analysis. A similar trend was observed in limited multivariable models; however, effect estimates were imprecise (HR = 4.01, 95% CI: 1.01–15.91, p = 0.048). Conclusions: This study indicates that perioperative decline in S-PA may reflect underlying cerebrovascular vulnerability and may be associated with subsequent adverse outcomes. However, given the limited number of events and potential for residual confounding, these findings should be interpreted with caution. Larger multicenter studies are required to validate these findings. Full article

Background: Flow diverters (FDs) are widely used to treat intracranial aneurysms. Although effective, FD-related thrombosis or progressive stenosis may lead to acute or delayed cerebral hypoperfusion with significant neurological morbidity. Management options are limited when medical or endovascular rescue strategies fail. This study aims to evaluate the role of extracranial–intracranial bypass (EC-IC bypass) as a rescue strategy across the spectrum of FD-related cerebral hypoperfusion. Methods: We retrospectively reviewed all patients who underwent EC-IC bypass for FD-related cerebral hypoperfusion over a 10-year period in our institution. Both acute and chronic presentations were included. Clinical status was assessed using the modified Rankin Scale (mRS). Imaging evaluation included digital subtraction angiography (DSA), computed tomography angiography (CTA), magnetic resonance angiography (MRA) and quantitative magnetic resonance imaging for bypass flow assessment. Surgical technique, antiplatelet therapy, timing of intervention and clinical outcomes were analysed. Results: Five patients with FD-related cerebral hypoperfusion who underwent superficial temporal artery–middle cerebral artery bypass (STA-MCA bypass) were identified. Two distinct patterns emerged. Three patients developed early hypoperfusion within the first month of FD placement, presenting with acute neurological deficits and treated by emergent or urgent bypass under dual antiplatelet therapy. Two patients developed late hypoperfusion years after the procedure, presenting with progressive haemodynamic symptoms and treated by elective flow-augmentation bypass under aspirin monotherapy. At discharge, only one patient had an mRS ≥ 3. At one-year follow-up, a favourable outcome (mRS ≤ 2) was observed in all patients with available data. Follow-up data were missing for one patient. Conclusions: EC-IC bypass represents a feasible rescue strategy for FD-related cerebral hypoperfusion when medical or endovascular treatments fail. In our experience, though limited, STA-MCA bypass can provide sufficient cerebral reperfusion, even in urgent settings and under dual antiplatelet therapy, leading to favourable neurological outcomes. Full article

Visualization of coronary computed tomography angiography (CCTA) in standard cardiac planes requires reorientation of the three-dimensional image volume because the heart is double-oblique relative to the axial scan plane. To standardize this process across multi-phase cine CCTA, we developed an automated framework that segments cardiac structures and detects anatomic landmarks to define a patient-specific cardiac coordinate system. Landmark-derived left ventricular (LV) long-axis and LV-to-right ventricular transverse vectors were used to compute a rotation matrix for reorienting all 20 cine CCTA volumes. Six fixed slice planes were then defined to extract three long-axis (LAX) and three short-axis (SAX) slices at each phase. Matched CCTA and cardiac magnetic resonance (MR) slices were compared in 25 patients at diastasis, end-diastole (ED), and end-systole (ES), using automated segmentation-derived measurements of the combined LV cavity and LV myocardium area (LV + LVM). Agreement was evaluated with intraclass correlation coefficients (ICCs), Bland–Altman analysis, and repeated-measures mixed-effects models. ICCs were 0.927 (95% CI, 0.895 to 0.950) at diastasis, 0.950 (95% CI, 0.928 to 0.966) at ED, and 0.919 (95% CI, 0.887 to 0.943) at ES. Bland–Altman analysis showed small CT-positive biases of 1.05, 0.47, and 1.86 cm² at diastasis, ED, and ES, corresponding to relative biases of 2.8%, 1.2%, and 5.8% of the phase-specific mean MR LV + LVM area. Mixed-effects models showed no statistically significant phase-level bias at diastasis or ED, whereas ES showed a small but significant CT-positive bias. These findings support automated CCTA reorientation as an interpretable framework for reproducible LAX/SAX slice extraction and future quantitative functional cine CCTA analysis. Full article

Neonatal thromboembolic (TE) disease is an increasingly recognized clinical entity, driven by the physiological uniqueness of developmental hemostasis, improved survival of preterm infants, and the widespread use of invasive supportive technologies. Most neonatal thrombotic events are associated with central venous and arterial catheterization which are considered the most significant modifiable risk factors. The clinical spectrum encompasses catheter-related thrombosis, perinatal stroke and site-specific entities such as renal vein and portal vein thrombosis. Each condition presents distinct challenges such as neurological complications, chronic organ dysfunction and portal hypertension. Diagnosis relies primarily on Doppler ultrasonography, though its sensitivity is limited in deep-vessel scenarios, often requiring advanced modalities like magnetic resonance imaging (MRI) or magnetic resonance angiography (MRA). Therapeutic interventions remain controversial due to a lack of high-quality evidence, with current guidelines largely based on observational data. Ultimately, managing neonatal TE requires a nuanced, individualized approach that balances the risk of thrombus extension against the inherent hemorrhagic vulnerability of the neonate. This review aims to provide a comprehensive and up-to-date overview of neonatal TE, emphasizing major clinical entities and diagnostic strategies. It highlights current evidence gaps and outlines future directions, including the need for standardized management protocols and high-quality prospective research. Full article

As abdominal aortic aneurysms (AAA) rupture results in a high mortality rate, early detection and risk stratification are critical for timely elective intervention. Although the maximum diameter is the sole imaging metric used to assess risk, other factors may provide complementary information. This study investigated the role of inflammation and hemodynamics in AAA progression. Methods: Patients with AAA underwent hybrid 18F-fluorodeoxyglucose ([18F]FDG) PET/CMR imaging, including a four-dimensional flow sequence and contrast-enhanced magnetic resonance angiography, and were followed to assess AAA diameter growth rate. Abdominal aorta hemodynamics and [18F]FDG PET target-to-background (TBR) were quantified at 28 standardized regions. Correlations between AAA diameter, hemodynamics, PET and growth rate were assessed. Results: Thirty-two AAA patients (84.4% men) with a median age of 73 and an interquartile range of [68; 77] years were prospectively recruited. The AAA maximum diameter was 48.1 [44.8; 55.0] mm, and the growth rate was 2.7 [1.3; 4.0] mm/year during a follow-up of 2 [1.1; 3.5] years. The AAA maximum diameter (R = 0.443, p = 0.011) and flow vorticity (R = 0.453, p = 0.009) showed significant bivariate correlation with the growth rate. When correcting for the aneurysm diameter, the helicity density was significantly correlated with the growth rate (p = 0.045), while the AAA thrombus volume was inversely associated with it (p = 0.042). Aneurysms with negative helicity density (counterclockwise rotation) grew significantly faster (p = 0.042) than those with positive helicity. In multivariable analysis, beyond the AAA diameter, the thrombus volume, helicity density and TBR were inversely related to the growth rate. Conclusions: Integrating flow, inflammatory and thrombus information may improve AAA growth rate prediction beyond the maximum aneurysm diameter. Full article

Popliteal artery aneurysms (PAA) lose their pulsatility once thrombosed and may therefore be mistaken for a Baker cyst or a soft-tissue tumor. A 58-year-old male presented with a 6-month history of progressive right popliteal swelling and pain, accompanied by right foot paresthesia and diminished distal pulses for two months. The presence of accompanying neurovascular deficits shifted the diagnostic consideration from a benign soft-tissue lesion to a vascular disorder. In this patient, non-contrast imaging protocol integrating grayscale ultrasound, power Doppler, and magnetic resonance imaging (MRI) successfully identified a chronically thrombosed popliteal artery aneurysm, supporting a vascular rather than neoplastic etiology. While ultrasound cannot replace contrast-enhanced MRI for definitive tissue characterization, its real-time capability established a vascular etiology and guided subsequent diagnostic digital subtraction angiography with urgent endovascular stent-graft reconstruction. Furthermore, serial ultrasonographic surveillance at three and 18 months confirmed long-term stent-graft patency and favorable aneurysmal sac remodeling. Neurovascular deficits accompanying a popliteal mass should redirect the workup toward vascular imaging. This case underscores a critical diagnostic pitfall, demonstrating that a stepwise strategy combining real-time ultrasound and non-contrast MRI ensures rapid definitive management for complex popliteal masses while preserving the unique role of sonography in non-invasive follow-up. Full article

Background: Autopsy pathology remains the reference standard for determining the cause of death, reconstructing disease and injury mechanisms, ensuring diagnostic quality, and supporting medical education and forensic investigations. However, declining autopsy rates, workforce shortages, biosafety concerns, increasing diagnostic complexity, and the rapid evolution of digital technologies have stimulated the development of complementary investigative approaches. This review critically examines whether artificial intelligence (AI) and emerging technologies are driving a genuine paradigm shift toward digitally integrated death investigation. Methods: A structured narrative review informed by a systematic literature search was conducted in PubMed/MEDLINE, Embase, Scopus, and Web of Science, covering publications from January 2000 through June 2026. Evidence addressing postmortem imaging, virtopsy, digital pathology, computational pathology, molecular autopsy, robotics, artificial intelligence, machine learning, and emerging omics technologies was critically appraised. Owing to the methodological heterogeneity of the available literature, findings were synthesized qualitatively according to technological maturity, forensic applicability, validation status, and implementation readiness. Results: The reviewed evidence demonstrates substantial progress in postmortem computed tomography, postmortem CT angiography, postmortem magnetic resonance imaging, whole-slide imaging, molecular autopsy, robotic-assisted postmortem procedures, three-dimensional reconstruction, and AI-assisted forensic analysis. These technologies enhance trauma evaluation, vascular imaging, ballistic reconstruction, digital documentation, remote consultation, diagnostic reproducibility, and multimodal integration of forensic evidence. Nevertheless, the level of evidence varies considerably across technological domains. Postmortem imaging represents the most mature and extensively validated technology, whereas most AI applications remain supported predominantly by retrospective proof-of-concept studies with limited multicenter external validation. Current systematic evidence further indicates that AI should presently be regarded as an assistive technology that augments expert forensic interpretation rather than replacing conventional autopsy or autonomous medicolegal decision-making. Conclusions: Contemporary autopsy pathology is evolving toward a hybrid model of digitally integrated death investigation in which conventional autopsy, imaging, digital pathology, molecular diagnostics, robotics, and AI function as complementary components of a unified forensic workflow. Current evidence supports a conceptual paradigm shift characterized by transformation of evidence acquisition, preservation, interpretation, and integration, while reaffirming that conventional autopsy remains the indispensable biological reference standard for the development, validation, and medicolegal interpretation of all emerging technologies. Future implementation should prioritize multicenter validation, standardized forensic datasets, explainable AI, digital chain-of-custody procedures, and robust regulatory governance to ensure safe and scientifically reliable integration into forensic practice. Full article

The carotid and vertebral arteries are critical components of the cerebral circulation, supplying the brain and spinal cord. Their embryologic development involves complex transformations of the aortic arches, paired dorsal aortae, and cervical intersegmental arteries. Congenital anomalies and variations involving their origin, course, and branching patterns are relatively common and are increasingly recognized using modern imaging. While many of these variants are incidental, some carry important clinical implications, particularly in contexts of stroke imaging, head and neck surgery, and neurointerventional procedures. This article reviews the embryologic development of the carotid and vertebral arterial systems, highlights normal and variant anatomy, and presents a case-based, illustrated overview of these congenital anomalies. Emphasis is placed on key findings utilizing computed tomography angiography (CTA), magnetic resonance angiography (MRA), and catheter angiography. Particular attention is given to structural and pathway variations, including vessel agenesis or hypoplasia, the aberrant internal carotid artery within the temporal bone, abnormal branching patterns, fenestrations, and persistent fetal anastomoses (such as the primitive trigeminal, hypoglossal, and proatlantal intersegmental arteries). Ultimately, familiarity with these anomalies, their embryological origins, and their distinct imaging characteristics is essential for ensuring accurate interpretation and avoiding diagnostic pitfalls and procedural complications. Full article

Spontaneous coronary artery dissection (SCAD) and Takotsubo syndrome (TTS) are two conditions presenting as acute coronary syndromes that predominantly affect women and are frequently triggered by emotional or physical stress. While traditionally considered distinct entities, emerging evidence suggests that these conditions may coexist more frequently than previously recognized, sharing common pathophysiological mechanisms centered on catecholamine-mediated pathways, vascular vulnerability, and hormonal influences. Their overlapping presentations create significant diagnostic challenges that may lead to misdiagnosis and suboptimal management. This narrative review examines the pathophysiological convergence between SCAD and TTS, addresses the diagnostic complexity arising when these entities coexist, and proposes a novel stepwise diagnostic algorithm integrating clinical risk stratification, coronary angiography, intracoronary imaging, and cardiac magnetic resonance imaging. The review also provides scenario-dependent management guidance and outlines priorities for future research. Full article

Background: Invasive coronary angiography has historically been the reference standard for coronary, valvular, and structural heart disease. Over the past decade, coronary computed tomography angiography (CCTA), CT-derived fractional flow reserve (CT-FFR), photon-counting detector computed tomography (PCCT), and cardiac magnetic resonance (CMR) have expanded the range of clinical questions answerable without an intra-arterial catheter, but this shift has been uneven across clinical domains. Methods: We performed a narrative review and synthesis of randomized trials, registries, society guidelines, and consensus documents (2009–2026) identified through PubMed and major cardiovascular guideline databases, written from a joint cardiology and cardiac-surgical standpoint. Results: The boundary has shifted asymmetrically, by which we mean a domain-dependent rather than uniform displacement of invasive angiography. Non-invasive imaging is now established as the first-line approach for stable chest pain at low-to-moderate pretest probability, for pre-transcatheter aortic valve replacement (TAVR) and structural procedural planning, and for aortic disease. It remains contested for stable multivessel disease and pre-coronary artery bypass grafting (CABG) planning, where CCTA- or CT-FFR-only planning is still investigational. Invasive angiography stays first-line for ST-elevation myocardial infarction (STEMI), cardiogenic shock, and complex percutaneous coronary intervention (PCI), where diagnosis and therapy are inseparable. Conclusions: Invasive and non-invasive modalities are complementary rather than competing. The appropriate first-line investigation depends on the disease domain, pretest probability, anatomical complexity, imaging quality, and whether diagnosis and treatment can be separated. We propose a complexity-stratified, heart-team framework and identify the surgical research gaps that remain. Full article

Objective: Systemic hypertension is a well-established risk factor for the development, growth, and rupture of intracranial aneurysms. However, its association with aneurysm recanalization after endovascular coil embolization remains unclear. This study aimed to evaluate the relationship between systemic hypertension and recanalization after coil embolization, and to identify additional risk factors associated with recanalization. Methods: We retrospectively analyzed 226 patients with 239 intracranial aneurysms treated by endovascular coil embolization between January 2010 and December 2017. Clinical, angiographic, and procedural variables were assessed. Hypertension was defined according to the Korean Society of Hypertension criteria based on a documented diagnosis or regular antihypertensive treatment. Radiological follow-up was performed primarily with magnetic resonance angiography, with digital subtraction angiography findings reviewed when available. Recanalization was assessed using the Raymond–Roy classification. Hierarchical multivariable logistic regression models were constructed using clinically selected covariates. Results: Of 239 aneurysms, 171 (71.5%) were treated in patients with hypertension, and recanalization occurred in 76 (31.8%) during a mean follow-up of 30.9 ± 14.0 months. Hypertension was not independently associated with recanalization (adjusted odds ratio (OR), 0.929; 95% confidence interval (CI), 0.447–1.930; p = 0.843). Ruptured presentation, larger aneurysm size, lower packing density, and an initial residual sac were independently associated with recanalization. Conclusions: Clinically defined systemic hypertension was not independently associated with recanalization after coil embolization. Ruptured presentation, larger aneurysm size, lower packing density, and an initial residual sac were independently associated with recurrence and may help inform post-treatment surveillance. Full article

Takotsubo syndrome (TTS) is an acute disorder characterized by transient left ventricular dysfunction with typical regional wall motion abnormalities, most commonly apical ballooning. It accounts for 1–3% of all suspected acute coronary syndromes and up to 5–6% in women presenting with ST-segment elevation myocardial infarction requiring coronary angiography to exclude obstructive coronary artery disease. The pathophysiology of TTS is complex and not fully elucidated, with sympathetic hyperactivation playing a central role through calcium dysregulation, oxidative stress, and metabolic alterations. Both clinical and experimental data demonstrate the importance of inflammation, with cell infiltration and persistent immune activation exceeding the acute phase. Increasing evidence highlights the impact of coronary microvascular disfunction (CMVD) as a secondary phenomenon, with some findings that support its role as a causative substrate. Beyond well-known predisposing conditions such as female sex, postmenopausal age, and neurological and psychiatric disorders with the trigger of a physical or psychological event, numerous case reports associate the syndrome with chronic autoimmune diseases, even if clear experimental evidence remains poor and worthy of further study. Echocardiography and advanced imaging techniques, including cardiac magnetic resonance and positron emission tomography, have provided insights into transient CMVD, reversible myocardial edema, and metabolic impairment, strengthening our knowledge of the syndrome as a dynamic process. It is also of growing interest to perform invasive hemodynamic assessment to explain the increase in microvascular resistance. This review offers a comprehensive and up-to-date overview of these techniques in the context of TTS. Since clinically, TTS may be associated with significant morbidity and mortality, with some unexplained cases of long-term myocardial disfunction or even recurrence, a deeper understanding of the interplay between catecholamines, inflammation, immune substrate, and CMVD may improve risk stratification and lead to the development of targeted therapeutic strategies. Full article

Myocardial infarction with non-obstructive coronary arteries (MINOCA) accounts for approximately 5–15% of all myocardial infarctions and disproportionately affects women. Once treated as a diagnosis of exclusion, MINOCA is now recognised as a heterogeneous, mechanism-based syndrome encompassing atherosclerotic plaque disruption, epicardial and microvascular vasospasm, microvascular dysfunction, coronary thromboembolism, and spontaneous coronary artery dissection (SCAD). Despite the absence of obstructive disease, it carries substantial morbidity and mortality, underscoring the need for accurate aetiological characterisation and tailored therapy. Our aim is to review the contemporary evidence of the role of advanced imaging modalities—cardiac magnetic resonance imaging (CMR), optical coherence tomography (OCT), intravascular ultrasound (IVUS) and invasive functional testing—in the diagnosis, prognostic stratification, and therapeutic guidance of patients with MINOCA. CMR is the non-invasive reference standard for differentiating true ischaemic MINOCA from non-ischaemic mimics such as myocarditis and Takotsubo syndrome, reclassifying the working diagnosis in up to two-thirds of cases. OCT and IVUS provide intracoronary characterisation of culprit substrates that are invisible via angiography, particularly plaque rupture, erosion, intramural haematoma and SCAD, while acetylcholine and adenosine testing identify endothelium-dependent vasospasm and endothelium-independent microvascular dysfunction respectively. Coronary Computed Tomography Angiography (CCTA) could also play an additional role in the diagnosis of epicardial CAD. Each modality additionally carries independent prognostic value, with abnormal findings consistently linked to higher rates of major adverse cardiovascular events. The recently completed PROMISE trial provided the first randomised evidence that stratified, imaging-guided treatment might have some positive impact on angina status and quality of life compared with empirical standard care. In conclusion, advanced imaging has transformed MINOCA from a diagnosis of exclusion into a mechanism-based syndrome amenable to personalised therapy. Broader integration of these modalities into routine practice, supported by further randomised trials, is needed to optimise outcomes. Full article