Computed tomography and nuclear medicine for the assessment of coronary inflammation: clinical applications and perspectives.

There is increasing evidence that in patients with atherosclerotic cardiovascular disease (ASCVD) under optimal medical therapy, a persisting dysregulation of the lipid and glucose metabolism, associated with adipose tissue dysfunction and inflammation, predicts a substantial residual risk of disease progression and cardiovascular events. Despite the inflammatory nature of ASCVD, circulating biomarkers such as high-sensitivity C-reactive protein and interleukins may lack specificity for vascular inflammation. As known, dysfunctional epicardial adipose tissue (EAT) and pericoronary adipose tissue (PCAT) produce pro-inflammatory mediators and promote cellular tissue infiltration triggering further pro-inflammatory mechanisms. The consequent tissue modifications determine the attenuation of PCAT as assessed and measured by coronary computed tomography angiography (CCTA). Recently, relevant studies have demonstrated a correlation between EAT and PCAT and obstructive coronary artery disease, inflammatory plaque status and coronary flow reserve (CFR). In parallel, CFR is well recognized as a marker of coronary vasomotor function that incorporates the haemodynamic effects of epicardial, diffuse and small-vessel disease on myocardial tissue perfusion. An inverse relationship between EAT volume and coronary vascular function and the association of PCAT attenuation and impaired CFR have already been reported. Moreover, many studies demonstrated that 18F-FDG PET is able to detect PCAT inflammation in patients with coronary atherosclerosis. Importantly, the perivascular FAI (fat attenuation index) showed incremental value for the prediction of adverse clinical events beyond traditional risk factors and CCTA indices by providing a quantitative measure of coronary inflammation. As an indicator of increased cardiac mortality, it could guide early targeted primary prevention in a wide spectrum of patients. In this review, we summarize the current evidence regarding the clinical applications and perspectives of EAT and PCAT assessment performed by CCTA and the prognostic information derived by nuclear medicine.

CTPA ordering trends in local emergency departments: are they increasing and did they increase as a result of COVID-19?

PURPOSE: Ordering trends for computed tomographic pulmonary angiogram (CTPA) studies by local emergency departments were assessed, along with the impact of the COVID-19 pandemic on these ordering trends and CTPA positivity rates. METHODS: A retrospective quantitative analysis was performed on all CTPA studies ordered between February 2018 - January 2022 by three local tertiary care emergency rooms to investigate for pulmonary embolism. Data collected from the first two years of the COVID-19 pandemic was compared to the two years prior to the pandemic to assess for significant changes in ordering trends and positivity rates. RESULTS: The overall number of CTPA studies ordered increased from 534 studies in 2018-2019 to 657 in 2021-2022 and the rate of positive diagnosis of acute pulmonary embolism varied between 15.8% to 19.5% over the four years studied. There was no statistically significant difference in the number of CTPA studies ordered when comparing the first two years of the COVID-19 pandemic to the two years immediately prior; however, the positivity rate was significantly higher during the first two years of the pandemic. CONCLUSION: Over the studied period from 2018-2022, the overall number of CTPA studies ordered by local emergency departments has increased, in line with literature reports from other locations. There was also a correlation between the onset of the COVID-19 pandemic and CTPA positivity rates, possibly secondary to the prothrombotic nature of this infection or the increase in sedentary lifestyles during lockdown periods.

SARS-CoV-2 antibody research in patients with unprovoked pulmonary embolism in COVID-19 pandemic period.

OBJECTIVE: Due to the coronavirus disease 2019 (COVID-19) pandemic, a significant increase has been observed in patients diagnosed with pulmonary embolism (PE) in our clinic. In addition to COVID-19-related PE, the increase in the number of patients with unprovoked or idiopathic PE was also noteworthy. Although it is not surprising that PE due to immobilization was observed in elderly patients and patients with comorbidities at risk for PE during the pandemic, it is important to investigate the increase in the number of unprovoked PE. Thus, we aimed to show that a previous COVID-19 infection may be a risk factor in these patients by examining the presence of severe acute respiratory syndrome-causing coronavirus (SARS-CoV-2) antibodies in patients diagnosed with unprovoked PE. MATERIALS AND METHODS: The participants of the study consisted of 45 consecutive patients who were diagnosed with PE in our clinic, had no risk factors for PE, were considered unprovoked (idiopathic) PE, and had no history of COVID-19. SARS-CoV-2 antibody titers were measured in the serum samples of the patients for detecting immunity as a result of encountering COVID-19. RESULTS: Of the 45 patients diagnosed with PE, 24 (53.3%) patients were diagnosed with computed tomography pulmonary angiogram (CTPA), and 21 (46.7%) patients were diagnosed with perfusion single-photon emission computed tomography (Q-SPECT/CT). Immunity acquired after encountering COVID-19 was checked with the NCP kit, which revealed positive results in 9 (20%) patients. CONCLUSION: It should be kept in mind that some of the patients diagnosed with idiopathic PE during the pandemic may have embolism due to asymptomatic COVID-19. In addition, it is now known that COVID-19 also creates a tendency toward thrombosis in asymptomatic patients.

Computed Tomography Pulmonary Angiography Utilization in the Emergency Department During the COVID-19 Pandemic.

PURPOSE: To determine if computed tomography pulmonary angiography (CTPA) ordering increased significantly during the COVID-19 pandemic in an emergency department (ED) setting; if positive findings for pulmonary embolism (PE) increased to the same degree; and whether COVID-positive patients have a higher incidence of PE than COVID-negative patients at ED presentation. MATERIALS AND METHODS: We conducted a retrospective review of CTPA performed in our ED between June and December in 2019 and 2020. We collected data on patient demographics, symptoms, COVID-19 status, lab and imaging results, and risk factors for PE. We used a Wilcoxon rank sum to analyze quantitative variables and χ2 or Fisher test for categorical variables. We used logistic regression to identify predictive factors for PE. RESULTS: CTPA ordering increased from 432 studies in 2019 to 699 in 2020 (+61.8%, P<0.0001), but detection rates for PE remained stable (11.3% vs. 10.2%, P=0.61). In 2020, 10 of 91 COVID-positive patients undergoing CTPA had positive studies. On regression analysis, COVID-19 was not a significant predictor of PE at ED presentation (odds ratio 1.029, 95% confidence interval: 0.959-1.103). COVID-positive patients were more likely to have nondiagnostic imaging (7.7% vs. 2.5% [COVID-negative] and 0.8% [not tested], P=0.007). CONCLUSIONS: While CTPA ordering increased significantly during the pandemic, our positivity rate remained stable, suggesting that this increase was appropriate. COVID-positive patients who underwent CTPA in the ED did not have a higher incidence of PE than other patients. Clinicians should use clinical judgment to weigh the likelihood of PE against the risk of nondiagnostic results when determining whether to expose COVID-positive patients to high-dose radiation and contrast with CTPA on initial presentation.

Bilateral pediatric pial arteriovenous fistulas accompanying a giant arachnoid cyst with torticollis: A case report.

RATIONALE: Pial arteriovenous fistula (PAVF) occurs when intracranial arteries communicate directly with veins. PAVFs are very rare congenital vascular lesions that are commonly seen in infants and children. Arachnoid cysts are congenital cavitation often filled with cerebrospinal fluid. We present a very rare associated occurrence of bilateral pediatric PAVF and a giant arachnoid cyst presenting as torticollis in a child. So far, this is the first case. PATIENT CONCERNS: A 6-year-old male child was referred to our facility from a local hospital due to severe torticollis. DIAGNOSES: An enhanced computed tomography scan revealed 2 slightly high-density masses at the anterior pontine cistern, right circumferential cistern, as well as left posterior occipital region. The same computed tomography scan revealed a giant arachnoid cyst in the left occipital as well as the temporal region with a thin cerebral cortex adjacent to the cyst. INTERVENTIONS: Digital subtraction angiography confirmed that the 2 high-flow lesions were PAVFs. The patient was treated with a combination of detachable coils and Onyx Liquid Embolic System (Onyx HD-500) (Covidien/ev3 Neurovascular) via the transarterial endovascular route while the giant arachnoid cyst was managed conservatively. OUTCOMES: The torticollis resolved 2 days after the procedure. He is currently well with no neurologic deficit. LESSONS: We advocate that in cases of PAVF with accompanying cyst, the cyst should be managed conservatively if it is not associated with intracranial hemorrhage or focal neurologic deficit.

Role of CT angiography in detecting acute pulmonary embolism associated with COVID-19 pneumonia.

PURPOSE: Recently coronavirus disease (COVID-19) caused a global pandemic, characterized by acute respiratory distress syndrome (ARDS). The aim of our study was to detect pulmonary embolism (PE) in patients with severe form of COVID-19 infection using pulmonary CT angiography, and its associations with clinical and laboratory parameters. METHODS: From March to December 2020, we performed a prospective monocentric study collecting data from 374 consecutive patients with confirmed SARS-CoV-2 infection, using real-time reverse-transcriptase polymerase-chain-reaction (rRT-PCR) assay of nasopharyngeal swab specimens. We subsequently selected patients with at least two of the following inclusion criteria: (1) severe acute respiratory symptoms (such as dyspnea, persistent cough, fever > 37.5 °C, fatigue, etc.); (2) arterial oxygen saturation ≤ 93% at rest; (3) elevated D-dimer (≥ 500 ng/mL) and C-reactive protein levels (≥ 0.50 mg/dL); and (4) presence of comorbidities. A total of 63/374 (17%) patients met the inclusion criteria and underwent CT angiography during intravenous injection of iodinated contrast agent (Iomeprol 400 mgI/mL). Statistical analysis was performed using Wilcoxon rank-sum and Chi-square tests. RESULTS: About, 26/60 patients (40%) were found positive for PE at chest CT angiography. In these patients, D-dimer and CRP values were significantly higher, while a reduction in SaO2 < 93% was more common than in patients without PE (P < 0.001). Median time between illness onset and CT scan was significantly longer (15 days; P < 0.001) in patients with PE. These were more likely to be admitted to the Intensive Care Unit (19/26 vs. 11/34 patients; P < 0.001) and required mechanical ventilation more frequently than those without PE (15/26 patients vs. 9/34 patients; P < 0.001). Vascular enlargement was significantly more frequent in patients with PE than in those without (P = 0.041). CONCLUSIONS: Our results pointed out that patients affected by severe clinical features of COVID-19 associated with comorbidities and significant increase of D-dimer levels developed acute mono- or bi-lateral pulmonary embolism in 40% of cases. Therefore, the use of CT angiography rather than non-contrast CT should be considered in these patients, allowing a better evaluation, that can help the management and improve the outcomes.

Malignant cerebral infarction after ChAdOx1 nCov-19 vaccination: a catastrophic variant of vaccine-induced immune thrombotic thrombocytopenia.

Vaccine-induced thrombotic thrombocytopenia with cerebral venous thrombosis is a syndrome recently described in young adults within two weeks from the first dose of the ChAdOx1 nCoV-19 vaccine. Here we report two cases of malignant middle cerebral artery (MCA) infarct and thrombocytopenia 9-10 days following ChAdOx1 nCoV-19 vaccination. The two cases arrived in our facility around the same time but from different geographical areas, potentially excluding epidemiological links; meanwhile, no abnormality was found in the respective vaccine batches. Patient 1 was a 57-year-old woman who underwent decompressive craniectomy despite two prior, successful mechanical thrombectomies. Patient 2 was a 55-year-old woman who developed a fatal bilateral malignant MCA infarct. Both patients manifested pulmonary and portal vein thrombosis and high level of antibodies to platelet factor 4-polyanion complexes. None of the patients had ever received heparin in the past before stroke onset. Our observations of rare arterial thrombosis may contribute to assessment of possible adverse effects associated with COVID-19 vaccination.

Pulmonary Embolism in Hospitalized Patients with COVID-19: A Multicenter Study.

Background Pulmonary embolism (PE) commonly complicates SARS-CoV-2 infection, but incidence and mortality reported in single-center studies, along with risk factors, vary. Purpose To determine the incidence of PE in patients with COVID-19 and its associations with clinical and laboratory parameters. Materials and Methods In this HIPAA-compliant study, electronic medical records were searched retrospectively for demographic, clinical, and laboratory data and outcomes among patients with COVID-19 admitted at four hospitals from March through June 2020. PE found at CT pulmonary angiography and perfusion scintigraphy was correlated with clinical and laboratory parameters. The d-dimer level was used to predict PE, and the obtained threshold was externally validated among 85 hospitalized patients with COVID-19 at a fifth hospital. The association between right-sided heart strain and embolic burden was evaluated in patients with PE undergoing echocardiography. Results A total of 413 patients with COVID-19 (mean age, 60 years ± 16 [standard deviation]; age range, 20-98 years; 230 men) were evaluated. PE was diagnosed in 102 (25%; 95% CI: 21, 29) of 413 hospitalized patients with COVID-19 who underwent CT pulmonary angiography or perfusion scintigraphy. PE was observed in 21 (29%; 95% CI: 19, 41) of 73 patients in the intensive care unit (ICU) versus 81 (24%; 95% CI: 20, 29) of 340 patients who were not in the ICU (P = .37). PE was associated with male sex (odds ratio [OR], 1.74; 95% CI: 1.1, 2.8; P = .02); smoking (OR, 1.86; 95% CI: 1.0, 3.4; P = .04); and increased d-dimer (P < .001), lactate dehydrogenase (P < .001), ferritin (P = .001), and interleukin-6 (P = .02) levels. Mortality in hospitalized patients was similar between patients with PE and those without PE (14% [13 of 102]; 95% CI: 8, 22] vs 13% [40 of 311]; 95% CI: 9, 17; P = .98), suggesting that diagnosis and treatment of PE were not associated with excess mortality. The d-dimer levels greater than 1600 ng/mL [8.761 nmol/L] helped predict PE with 100% sensitivity and 62% specificity in an external validation cohort. Embolic burden was higher in patients with right-sided heart strain among the patients with PE undergoing echocardiography (P = .03). Conclusion Pulmonary embolism (PE) incidence was 25% in patients hospitalized with COVID-19 suspected of having PE. A d-dimer level greater than 1600 ng/mL [8.761 nmol/L] was sensitive for identification of patients who needed CT pulmonary angiography. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Ketai in this issue.

Upper extremity arterial thromboembolism in a patient with severe COVID-19 pneumonia: A case report.

Although novel coronavirus-2019 (COVID-19) primarily affects the respiratory system, it can affect multiple organ systems, leading to serious complications, such as acute respiratory distress syndrome (ARDS) and multiple organ failure. Nearly 20 to 55% of patients with COVID-19 experience coagulation disorders that cause high mortality in line with the severity of the clinical picture. Thromboembolism can be observed in both venous and arterial systems. The vast majority of thromboembolic events are associated with the venous system and are often observed as pulmonary embolism. Arterial thromboembolisms often involve the arteries in the lower extremities, followed by those in the upper extremities. Herein, we report a rare case of COVID-19 pneumonia whose left arm was amputated at the forearm level after arterial thromboembolism in the left upper extremity. This case report is valuable, as it is the first reported case of upper extremity arterial thromboembolism in Turkey, as well as the only case in the literature in which the patient underwent four surgical interventions and is still alive.

Risk of acute pulmonary embolism in COVID-19 pneumonia compared to community-acquired pneumonia: a retrospective case-control study.

AIM: To compare the incidence of pulmonary embolism (PE) in COVID-19 pneumonia and non-COVID-19-related community-acquired pneumonia (CAP) in hospitalised patients. MATERIALS AND METHODS: A retrospective case-control study was conducted. This included patients hospitalised with pneumonia and investigated for suspected PE with computed tomography pulmonary angiogram (CTPA). Cases were defined as patients with COVID-19 pneumonia from 1 March 2020 to 17 May 2020; controls were patients with CAP from 5 July 2019 to 31 January 2020. The primary outcome was to determine the risk of developing PE in both groups. Multivariable logistic regression was used to calculate the adjusted odds ratio for PE. RESULTS: One hundred and forty-four patients were included; 72 cases (47% male; mean age 59 (±15) years), and 72 controls (56% male; mean age 58 (±20) years). PE was diagnosed in 23.6% of the cases versus 6.9% of the controls. The adjusted odds ratio for PE in hospitalised patients with COVID-19 pneumonia compared with those with CAP was 3.23 (95% confidence interval [CI] 1.04-10.04, p=0.04). CONCLUSION: The odds of developing PE in hospitalised patients with COVID-19 pneumonia are three-times higher than in those with CAP. The results provide a quantitative assessment of the risk of PE in COVID-19 pneumonia, a condition new to healthcare, compared to other forms of pneumonia with a well-established scientific basis.

Pulmonary Artery Filling Defects in COVID-19 Patients Revealed Using CT Pulmonary Angiography: A Predictable Complication?

PURPOSE: This study is aimed at assessing the prevalence of pulmonary artery filling defects (PAFDs) consistent with pulmonary artery embolism (PAE) in patients with SARS-CoV-2 infection and at investigating possible radiological or clinical predictors. MATERIALS AND METHODS: Computed Tomography Pulmonary Angiographies (CTPAs) from 43 consecutive patients with a confirmed COVID-19 infection were retrospectively reviewed, taking into consideration the revised Geneva score and the D-dimer value for each patient. Filling defects within the pulmonary arteries were recorded along with pleural and parenchymal findings such as ground glass opacities, consolidation, crazy paving, linear consolidation, and pleural effusion. All these variables were compared between patients with and without PAFD. The predictive performance of statistically different parameters was investigated using the receiver operating characteristics (ROC). RESULTS: Pulmonary embolism was diagnosed in 15/43 patients (35%), whereas CTPA and parenchymal changes related to pulmonary COVID-19 disease were evident in 39/43 patients (91%). The revised Geneva score and the mean D-dimer value obtained using two consecutive measurements were significantly higher in patients with PAFD. The ROC analysis demonstrated that a mean D-dimer value is the parameter with the higher predictivity (AUC 0.831) that is a cut-off value > 1800 µg/l which predicts the probability of PAFD with a sensitivity and specificity of 70% and 78%, respectively. CONCLUSIONS: This single centre retrospective report shows a high prevalence of pulmonary artery filling defects revealed using CTPA in COVID-19 patients and demonstrates that the mean value of multiple D-dimer measurements may represent a predicting factor of this complication.

CT coronary angiography and COVID-19: inpatient use in acute chest pain service.

OBJECTIVES: CT coronary angiography (CTCA) is a well-validated clinical tool in the evaluation of chest pain. In our institution, CTCA availability was increased in January 2020, and subsequently, expanded further to replace all exercise testing during the COVID-19 pandemic. Our objective was to assess the impact of increased utilisation of CTCA on length of stay in patients presenting with chest pain in the prepandemic era and during the COVID-19 pandemic. METHODS: Study design was retrospective. Patients referred for cardiology review between October 2019 and May 2020 with chest pain and/or dyspnoea were broken into three cohorts: a baseline cohort, a cohort with increased CTCA availability and a cohort with increased CTCA availability, but after the national lockdown due to COVID-19. Coronary angiography and revascularisation, length of stay and 30-day adverse outcomes were assessed. RESULTS: 513 patients (35.3% female) presented over cohorts 1 (n=179), 2 (n=182), and 3 (n=153). CTCA use increased from 7.8% overall in cohort 1% to 20.4% in cohort 3. Overall length of stay for the patients undergoing CTCA decreased from a median of 4.2 days in cohort 1 to 2.5 days in cohort 3, with no increase in 30 days adverse outcomes. Invasive coronary angiogram rates were 45.8%, 39% and 34.2% across the cohorts. 29.6% underwent revascularisation in cohort 1, 15.9% in cohort 2 and to 16.4% in cohort 3. CONCLUSIONS: Increased CTCA availability was associated with a significantly reduced length of stay both pre-COVID-19 and post-COVID-19 lockdown, without any increase in 30-day adverse outcomes.

Qualitative and quantitative DECT pulmonary angiography in COVID-19 pneumonia and pulmonary embolism.

AIM: To assess differences in qualitative and quantitative parameters of pulmonary perfusion from dual-energy computed tomography (CT) pulmonary angiography (DECT-PA) in patients with COVID-19 pneumonia with and without pulmonary embolism (PE). MATERIALS AND METHODS: This retrospective institutional review board-approved study included 74 patients (mean age 61±18 years, male:female 34:40) with COVID-19 pneumonia in two countries (one with 68 patients, and the other with six patients) who underwent DECT-PA on either dual-source (DS) or single-source (SS) multidetector CT machines. Images from DS-DECT-PA were processed to obtain virtual mono-energetic 40 keV (Mono40), material decomposition iodine (MDI) images and quantitative perfusion statistics (QPS). Two thoracic radiologists determined CT severity scores based on type and extent of pulmonary opacities, assessed presence of PE, and pulmonary parenchymal perfusion on MDI images. The QPS were calculated from the CT Lung Isolation prototype (Siemens). The correlated clinical outcomes included duration of hospital stay, intubation, SpO2 and death. The significance of association was determined by receiver operating characteristics and analysis of variance. RESULTS: One-fifth (20.2%, 15/74 patients) had pulmonary arterial filling defects; most filling defects were occlusive (28/44) located in the segmental and sub-segmental arteries. The parenchymal opacities were more extensive and denser (CT severity score 24±4) in patients with arterial filling defects than without filling defects (20±8; p=0.028). Ground-glass opacities demonstrated increased iodine distribution; mixed and consolidative opacities had reduced iodine on DS-DECT-PA but increased or heterogeneous iodine content on SS-DECT-PA. QPS were significantly lower in patients with low SpO2 (p=0.003), intubation (p=0.006), and pulmonary arterial filling defects (p=0.007). CONCLUSION: DECT-PA QPS correlated with clinical outcomes in COVID-19 patients.

New onset severe right ventricular failure associated with COVID-19 in a young infant without previous heart disease.

We present our recent experience with a 6-month-old infant with a personal history of short bowel syndrome that presented with fever, cyanosis, and cardiogenic shock secondary to severe pulmonary hypertension and right ventricular failure without pulmonary thromboembolism. He did not present signs of toxin-mediated disease or Kawasaki disease. He was finally diagnosed with SARS-CoV-2 infection. If this presentation is confirmed in future research, the severe cardiovascular impairment in children with COVID-19 could be also attributable to the primary pulmonary infection, not only to a multisystem inflammatory syndrome but also in children without heart disease.

Aortoenteric fistula after endovascular mycotic aortic aneurysm exclusion: lessons learned during the COVID-19 era.

We report a case of aortoenteric fistula 2 years following endovascular aortic aneurysm repair (EVAR) for mycotic aneurysm presenting as upper gastrointestinal bleeding. Initial CT angiogram did not reveal the bleeding or connection to bowel, but endoscopy was suspicious of endograft in the duodenum. Management required a multidisciplinary approach. To stabilise the patient and to control bleeding, a 'bridging' endograft extension was performed. This was followed by open surgical removal of the EVAR endograft and lower limb in situ revascularisation. During postoperative recovery, the patient developed atypical, staged multisystemic symptoms (cardiac, pulmonary and neurological). With increasing awareness of the COVID-19 pandemic, the patient was found SARS-CoV-2-positive, which explained the progression of his symptoms. This was also reflected on other case reports in literature later.