Lung Abnormalities in Severe Acute Respiratory Syndrome Coronavirus 2 Infection: An Analysis of Paired Computed Tomography Scans Before and After Infection.

Background: Studies on the pulmonary consequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are impeded by limited access to pre-SARS-CoV-2 examinations. Methods: We invited Copenhagen General Population Study participants with a confirmed SARS-CoV-2 polymerase chain reaction (PCR) test during the first and second coronavirus disease 2019 waves in Denmark for a repeat chest computed tomography (CT) scan. Paired CT scans were independently assessed for interstitial and noninterstitial abnormalities by 2 trained radiologists. A semiquantitative CT score (ranging from 0 to 20) was used to quantify the extent of interstitial abnormalities. Results: Of 111 SARS-CoV-2-infected individuals, 102 (91.2%) experienced symptoms and 12 (11.2%) were hospitalized. Follow-up examination was performed at median of 5.4 (interquartile range, 4.1-7.8) months after a positive SARS-CoV-2 PCR test. Of 67 individuals with paired CT scans, ground glass opacities and reticulation were present in 31 (46.3%) individuals post-SARS-CoV-2 compared to 23 (34.1%) pre-SARS-CoV-2 (mean CT score, 3.0 vs 1.3; P = .011). Results were similar for nonhospitalized individuals. We did not detect development of bronchiectasis, emphysema, or nodules. Conclusions: SARS-CoV-2 infection in predominantly nonhospitalized individuals with mild disease was associated with a small increase in only interstitial lung abnormalities.

Assessment of sarcopenia in patients with upper gastrointestinal tumors: Prevalence and agreement between computed tomography and dual-energy x-ray absorptiometry.

BACKGROUND & AIMS: Sarcopenia is associated with an increased risk of complications to treatment and lower survival rates in patients with cancer, but there is a lack of agreement on cut-off values and assessment methods. We aimed to investigate the prevalence of sarcopenia assessed by dual-energy x-ray absorptiometry (DXA) and computed tomography (CT) as well as the agreement between the methods for identification of sarcopenia. METHODS: This cross-sectional study pooled data from two studies including patients scheduled for surgery for gastrointestinal tumors. We assessed sarcopenia using two different cut-off values derived from healthy young adults for DXA and two for CT. Additionally, we used one of the most widely applied cut-off values for CT assessed sarcopenia derived from obese cancer patients. The agreement between DXA and CT was evaluated using Cohen's kappa. The mean difference and range of agreement between DXA and CT for estimating total and appendicular lean soft tissue were assessed using Bland-Altman plots. RESULTS: In total, 131 patients were included. With DXA the prevalence of sarcopenia was 11.5% and 19.1%. Using CT, the prevalence of sarcopenia was 3.8% and 26.7% using cut-off values from healthy young adults and 64.1% using the widely applied cut-off value. The agreement between DXA and CT in identifying sarcopenia was poor, with Cohen's kappa values ranging from 0.05 to 0.39. The mean difference for estimated total lean soft tissue was 1.4 kg, with 95% limits of agreement from -8.6 to 11.5 kg. For appendicular lean soft tissue, the ratio between DXA and CT was 1.15, with 95% limits of agreement from 0.92 to 1.44. CONCLUSIONS: The prevalence of sarcopenia defined using DXA and CT varied substantially, and the agreement between the two modalities is poor.

Coronary CT angiography in clinical triage of patients at high risk of coronary artery disease.

OBJECTIVES: To test if cardiac computed tomography angiography (CCTA) can be used in the triage of patients at high risk of coronary artery disease. DESIGN: The diagnostic value of 64-detector CCTA was evaluated in 400 patients presenting with non-ST segment elevation myocardial infarction using invasive coronary angiography (ICA) as the reference method. The relation between the severity of disease by CCTA and a combined endpoint of death, re-hospitalization due to new myocardial infarction, or symptom-driven coronary revascularization was assessed. RESULTS: CCTA detects significant (>50%) coronary artery diameter stenosis with a sensitivity, specificity, and positive and negative predictive value of 99%, 81%, 96% and 95%, respectively. CCTA was used to triage patients into guideline defined treatment groups of "no or medical treatment", "referral to percutaneous coronary intervention" or to "coronary artery bypass graft surgery" and was compared to the index ICA. CCTA correctly triaged patients in 86% of cases. During a median follow-up of 50 months, the presence of an occluded artery by CCTA was associated with adverse outcome. CONCLUSION: CCTA has high diagnostic and prognostic value in patients with high likelihood of coronary artery disease and could, in theory, be used to triage high risk patients. As many obstacles remain, including logistical and safety issues, our study does not support the use of CCTA as an additional diagnostic test before ICA in an all-comer NSTEMI population.

Data on the quantitative assessment pulmonary ground-glass opacification from coronary computed tomography angiography datasets.

We assessed the CT attenuation density of the pulmonary tissue adjacent to the heart in patients with acute non-ST segment elevation myocardial infarction (J.T. Kuhl, T.S. Kristensen, A.F. Thomsen et al., 2016) [1]. This data was related to the level of ground-glass opacification evaluated by a radiologist, and data on the interobserver variability of semi-automated assessment of pulmonary attenuation density was provided.

Clinical and prognostic correlates of pulmonary congestion in coronary computed tomography angiography data sets.

BACKGROUND: Signs of pulmonary congestion obtained from cardiac computed tomography angiographic (coronary CTA) images have not previously been related to clinical congestion or outcome and the clinical value is, therefore, unknown. Our objective was to test the hypothesis that signs of pulmonary congestion predict clinical heart failure and adverse outcome in patients with myocardial infarction. METHODS: Coronary CTA was performed before invasive treatment in 400 prospectively included patients with non ST segment elevation myocardial infarction in an observational study. Using a previously described chest computed tomography evaluation algorithm, patients were classified as having "no congestion", "mild to moderate congestion" or "severe congestion". RESULTS: Using multivariate analyses, presence of pulmonary congestion on coronary CTA images was associated with age, female gender, left ventricular ejection fraction (LVEF) and left atrial size. The diagnostic accuracy for predicting clinical heart failure, defined as Killip class >1, was: sensitivity: 83%, specificity: 69%, positive predictive value: 25%, and negative predictive value: 97%. The median follow-up time was 50 months and the study end-point of death or hospitalization due to heart failure was reached in 68 (16%) patients. In a Cox proportional hazards model with adjustments for known risk factors and Killip class, the presence of "mild to moderate congestion" and "severe congestion" was independently associated with adverse outcome (Hazard ratio: 2.6 (95% CI:1.3-5.0) and 3.2 (1.3-7.5)). CONCLUSION: Signs of pulmonary congestion on coronary CTA images are closely correlated to cardiac dysfunction, predict clinical heart failure, and provide prognostic value independent of LVEF and Killip class.

Dynamic Contrast-Enhanced CT in Patients with Pancreatic Cancer.

The aim of this systematic review is to provide an overview of the use of Dynamic Contrast-enhanced Computed Tomography (DCE-CT) in patients with pancreatic cancer. This study was composed according to the PRISMA guidelines 2009. The literature search was conducted in PubMed, Cochrane Library, EMBASE, and Web of Science databases to identify all relevant publications. The QUADAS-2 tool was implemented to assess the risk of bias and applicability concerns of each included study. The initial literature search yielded 483 publications. Thirteen articles were included. Articles were categorized into three groups: nine articles concerning primary diagnosis or staging, one article about tumor response to treatment, and three articles regarding scan techniques. In exocrine pancreatic tumors, measurements of blood flow in eight studies and blood volume in seven studies were significantly lower in tumor tissue, compared with measurements in pancreatic tissue outside of tumor, or normal pancreatic tissue in control groups of healthy volunteers. The studies were heterogeneous in the number of patients enrolled and scan protocols. Perfusion parameters measured and analyzed by DCE-CT might be useful in the investigation of characteristic vascular patterns of exocrine pancreatic tumors. Further clinical studies are desired for investigating the potential of DCE-CT in pancreatic tumors.

Assessing Tumor Response to Treatment in Patients with Lung Cancer Using Dynamic Contrast-Enhanced CT.

The aim of this study was to provide an overview of the literature available on dynamic contrast-enhanced computed tomography (DCE-CT) as a tool to evaluate treatment response in patients with lung cancer. This systematic review was compiled according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only original research articles concerning treatment response in patients with lung cancer assessed with DCE-CT were included. To assess the validity of each study we implemented Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). The initial search yielded 651 publications, and 16 articles were included in this study. The articles were divided into groups of treatment. In studies where patients were treated with systemic chemotherapy with or without anti-angiogenic drugs, four out of the seven studies found a significant decrease in permeability after treatment. Four out of five studies that measured blood flow post anti-angiogenic treatments found that blood flow was significantly decreased. DCE-CT may be a useful tool in assessing treatment response in patients with lung cancer. It seems that particularly permeability and blood flow are important perfusion values for predicting treatment outcome. However, the heterogeneity in scan protocols, scan parameters, and time between scans makes it difficult to compare the included studies.

Accuracy of multi-slice computed tomography for measurement of left ventricular ejection fraction compared with cardiac magnetic resonance imaging and two-dimensional transthoracic echocardiography: a systematic review and meta-analysis.

BACKGROUND: Multi-slice computed tomography (MSCT) allows non-invasive assessment of the coronary arteries and simultaneously can provide measurement of left ventricular ejection fraction (LVEF). The accuracy of newer MSCT generations (64-slice or more) for assessment of LVEF compared with magnetic resonance imaging (MRI) and two-dimensional transthoracic echocardiography (TTE) has not been evaluated in a meta-analysis. PURPOSE: To evaluate, via a systematic literature review and meta-analysis, whether MSCT can assess LVEF with high accuracy compared with MRI and TTE. METHODS: Electronic databases and reference lists for relevant published studies were searched. Twenty-seven eligible studies provided mean LVEF% with its standard deviation (SD) measured by MSCT versus MRI and TTE. Meta-analysis of weighted mean difference (WMD) and Bland-Altman method were used to quantify the mean difference and agreement between MSCT compared with MRI and TTE. RESULTS: The results of combining 12 studies showed no significant difference in LVEF% between MSCT and MRI with a WMD of -0.11 (-1.48, 1.26, 95% CI), p=0.88. Bland-Altman analysis showed excellent agreement between MSCT and MRI with a bias of 0.0 (-3.7, 3.7 ± 1.96SD) with 95% CI. The results of combining 15 studies showed no significant difference in LVEF between MSCT versus TTE measurements with a WMD of 0.19 (-1.13 to 1.50; 95% CI), p=0.87. Bland-Altman analysis showed excellent agreement between MSCT and TTE with a bias of 0.3 (-4.7, 5.7 ± 1.96SD) with 95% CI. CONCLUSION: The newer MSCT generations can provide accurate LVEF measurement compared to MRI and TTE. MSCT represents a valid technique for the combined evaluation of LVEF and coronary artery disease.

Patterns of myocardial perfusion in humans evaluated with contrast-enhanced 320 multidetector computed tomography.

Left ventricular (LV) myocardial contrast enhancement can be recorded using 320 multi detector computed tomography (MDCT). We aimed to (1) assess patterns of regional myocardial perfusion at rest and compare them with NH(3) positron emission tomography (PET) (2) and to assess the effect of intravenous adenosine infusion on regional myocardial perfusion. To evaluate myocardial perfusion patterns at rest, we scanned 14 healthy subjects with PET and 14 age and gender matched subjects with 320 MDCT. To evaluate the effect of adenosine stress on relative perfusion patterns 14 subjects with near-normal epicardial coronary arteries were studied at rest and during adenosine stress. Relative perfusion was assessed as attenuation density (AD) in 16 segments of the LV, and each segment was divided into 3 layers: endo-, mid- and epi-cardial. During rest the relative AD by MDCT was lower in the lateral wall compared with the remainder of the LV (P < 0.002). A similar pattern was found by PET-imaging. LV endocardial AD was higher than mid- and epicardial AD (P < 0.05). At rest the endocardial/epicardial ratio in the septum was 0.99 compared with 1.23 in non-septal segments (P < 0.001). During adenosine infusion transmural AD increased due to significant increases in the mid- and epicardium and the endocardial/epicardial ratio decreased by 18% in non-septal segments (from 1.23 to 1.05 P < 0.001). Relative perfusion at rest is lower in the lateral wall of the LV with both PET and MDCT compared to the remainder of the myocardium. During adenosine stress endocardial/epicardial ratio decrease significantly.

Left atrial function and mortality in patients with NSTEMI an MDCT study.

OBJECTIVES: We sought to test the hypothesis that measures of left atrial (LA) function are independent predictors of mortality in patients with acute myocardial infarction. BACKGROUND: Left atrial maximal volume (LAmax) is known to predict mortality in patients with acute myocardial infarction. In a previous pilot study, however, we found that LA function in terms of fractional change and left atrial ejection fraction (LAEF) assessed by multidetector computed tomography (MDCT) is more closely related to clinical heart failure than LAmax. METHODS: We prospectively included 384 patients presenting with non-ST-segment elevation myocardial infarction (NSTEMI) who underwent retrospectively gated, 64-slice MDCT coronary angiography and subsequent measurements of LA size and function. All patients were treated according to the current guidelines based on invasive coronary angiography. Patients were followed for a minimum of 2 years. The study endpoint was all-cause mortality. RESULTS: The median follow-up time was 36 months (range 10 to 1,551 days). During follow-up, 35 (9%) patients died. Overall, 1- and 2-year survival in the study cohort was 97% and 94%. LA size and mechanical function was obtained in all patients: mean LAmax was 55 ± 11 ml/m(2), LA minimal volume 31 ± 11 ml/m(2), fractional change 45 ± 9%, and LAEF 32 ± 9%. Using a Cox proportional hazards model with adjustments for age, number of diseased coronary vessels, left ventricular ejection fraction (LVEF), and Killip class, both fractional change (hazard ratio [HR]: 0.65; 95% confidence interval [CI]: 0.45 to 0.94) and LAEF (HR: 0.63; 95% CI: 0.44 to 0.91) remained independent predictors of mortality. In contrast to this, LAmax was not significantly associated with an increased risk of mortality in this population. CONCLUSIONS: In a low-risk group of patients with NSTEMI, reduced LA function is an independent predictor of mortality and provides prognostic value incremental to that of LAmax.

Prognostic implications of nonobstructive coronary plaques in patients with non-ST-segment elevation myocardial infarction: a multidetector computed tomography study.

OBJECTIVES: We sought to determine whether the amount of noncalcified plaque (NCP) in nonobstructive coronary lesions as detected by multidetector computed tomography (MDCT) was a predictor of future coronary events. BACKGROUND: Patients presenting with non-ST-segment elevation myocardial infarction (NSTEMI) frequently have multiple coronary plaques, which may be detected with MDCT. METHODS: We included 312 consecutive patients presenting with NSTEMI, who underwent 64-slice MDCT coronary angiography and coronary artery calcium scoring before invasive coronary angiography. All patients were treated according to current guidelines based on an invasive treatment approach. Quantitative measurements of plaque composition and volume were performed by MDCT in all nonobstructive coronary lesions. The endpoint was cardiac death, acute coronary syndrome, or symptom-driven revascularization. RESULTS: After a median follow-up of 16 months, 23 patients had suffered a cardiac event. Age, male sex, and diabetes mellitus were all associated with an increasing amount of NCP. In a multivariate regression analysis for events, the total amount of NCP in nonobstructive lesions was independently associated with an increased hazard ratio (1.18/100-mm(3) plaque volume increase, p = 0.01). Contrary to this, neither Agatston score nor the amount of calcium in nonobstructive lesions was associated with an increased risk. CONCLUSIONS: Multidetector computed tomography plaque imaging identified patients at increased risk of recurrent coronary events after NSTEMI by measuring the total amount of NCP in nonobstructive lesions. The amount of calcified plaque was not associated with an increased risk.

Quantitative assessment of left ventricular systolic wall thickening using multidetector computed tomography.

BACKGROUND: Multidetector computed tomography (MDCT) of the heart provides both anatomical and functional information. The objective of this study was to evaluate the accuracy of quantitative assessment of left ventricular contractile function in relation to two-dimensional transthoracic echocardiography (TTE). MATERIALS AND METHODS: Sixty-four patients with known or suspected coronary artery disease underwent ECG-gated 64-slice MDCT and TTE. Regional left ventricular contractile function was measured by percent systolic wall thickening (SWT) in 16 myocardial segments using MDCT, and compared with visual evaluation of wall motion score (WMS) by TTE. Global SWT by MDCT was calculated as the mean SWT of all myocardial segments and compared with wall motion index (WMI) by TTE. RESULTS: Eight hundred and eleven segments (81%) were classified as normokinetic, 142 (14%) as hypokinetic, 41 (4%) as akinetic and 5 (0.5%) as dyskinetic by TTE. A significant inverse linear trend was found between regional SWT by MDCT and WMS by TTE (p<0.001). Sensitivity and specificity for the identification of regional abnormalities of contractile function were 76% and 78%, respectively. A linear correlation between global SWT by MDCT and WMI by TTE was found (r=-0.8, p<0.001). Sensitivity and specificity for the identification of WMI>1.5 using global SWT was 91% and 94%, respectively. CONCLUSION: Quantification of systolic wall thickening by MDCT provides functional information, which is well correlated to visual assessment of global left ventricular contractile function by TTE.

Acute stent thrombosis after bifurcation stenting with the crush technique visualized with 64-slice computed tomography.

Acute stent thrombosis remains a potential complication after stent implantation. With the introduction of electrocardiographic gated multidetector row computed tomography (MDCT), a new nonnvasive imaging modality has become available that may contribute to the detection of complications after complex interventional procedures. We present a case where CT angiography was performed just prior to the clinical presentation of acute stent thrombosis in a 55-year-old male who was treated with the crush technique in a bifurcation lesion.