Mean Computed Tomography Research Articles

Predicting mortality rate in ICU admitted COVID-19 patients implementing visual semi-quantitative CT severity scoring system

Objectives: The aim of this study was to identify the clinical and laboratory features and CT scan (CT intensity score and pleural effusion) associated with COVID-19 pneumonia to evaluate the relationship between CT scan findings and mortality by comparing deceased patients with normal patients. Methods: In this retrospective case-control study, 290 ICU admitted patients with RT-PCR confirmed COVID-19 pneumonia were investigated. Totally, 150 deceased patients (with confirmed COVID-19 related death) were extracted from the COVID-19 registry of the affiliated university hospital belonging to mentioned period of time (in-hospital mortality subgroup, case), and 150 patients who survived the admission course were randomly selected from the same data set (surviving subgroup, control). Available electronic records for each patient were enlisted, including laboratory and clinical information, and their on-admission Computed Tomography (CT) images were reviewed. Mortality-related risk factors were compared between case and control subgroups. Results: The mean age of deceased patients (68.20 ± 16.07) was significantly higher than that of the surviving patients (54.72 ± 19.50) (p<0.001). Diabetes, hypertension, and Chronic Kidney Disease (CKD) were significantly related with higher mortality rates (62.2%, 58.7%, and 80.4% mortality in diabetic, hypertensive, and CKD patients versus 41.7%, 42.1%, and 35.9% in non-diabetics, normotensives, and patients without CKD). Additionally, the mean on-admission air-room SPO2 level in deceased patients (90%) was significantly lower than that of the survivors (93%) (p = 0.001). Lymphocyte count, Neutrophil to Lymphocyte Ratio (NLR), Erythrocyte Sedimentation Rate (ESR), CReactive Protein (CRP), Lactate Dehydrogenase (LDH), Fasting Blood Sugar (BS), Blood Urea Nitrogen (BUN), and Creatinine (Cr), mean CT Severity Score (CT-ss), and O2 supportive therapy requirement were significantly higher in the mortality subgroup (p<0.05). Pleural effusion showed no significant correlation with short-term mortality. CTss of >11, in isolation or in combination with above-mentioned prognosticators, was 64% or 81.4% sensitive, and 60% or of 78.6% specific, to predict mortality. Conclusions: Factors such as advanced age, underlying diseases such as diabetes, hypertension, and CKD, decreased air-room SPO2 , and increased lymphocyte count, higher NLR, ESR, CRP, LDH, BS, BUN, and Cr level, as well as higher CT-ss and O2 supportive therapy, are all significantly correlated with higher mortality in ICU-admitted COVID-19 patients. Keywords: COVID-19; CT scan; CT Severity score; ICU; pneumonia.

Predicting Mortality Rate in ICU-Admitted COVID-19 Patients Implementing Visual Semi-Quantitative CT Severity Scoring System

Objectives: The aim of this study was to identify the clinical and laboratory features and CT scan (CT intensity score and pleural effusion) associated with COVID-19 pneumonia to evaluate the relationship between CT scan findings and mortality by comparing deceased patients with normal patients. Methods: In this retrospective case-control study, 290 ICU admitted patients with RT-PCR confirmed COVID-19 pneumonia were investigated. Totally, 150 deceased patients (with confirmed COVID-19 related death) were extracted from the COVID-19 registry of the affiliated university hospital belonging to mentioned period of time (in-hospital mortality subgroup, case), and 150 patients who survived the admission course were randomly selected from the same data set (surviving subgroup, control). Available electronic records for each patient were enlisted, including laboratory and clinical information, and their on-admission Computed Tomography (CT) images were reviewed. Mortalityrelated risk factors were compared between case and control subgroups. Results: The mean age of deceased patients (68.20 ± 16.07) was significantly higher than that of the surviving patients (54.72 ± 19.50) (p <0.001). Diabetes, hypertension, and Chronic Kidney Disease (CKD) were significantly related with higher mortality rates (62.2%, 58.7%, and 80.4% mortality in diabetic, hypertensive, and CKD patients versus 41.7%, 42.1%, and 35.9% in non-diabetics, normotensives, and patients without CKD). Additionally, the mean on-admission air-room SPO2 level in deceased patients (90%) was significantly lower than that of the survivors (93%) (p = 0.001). Lymphocyte count, Neutrophil to Lymphocyte Ratio (NLR), Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein (CRP), Lactate Dehydrogenase (LDH), fasting Blood Sugar (BS), Blood Urea Nitrogen (BUN), and Creatinine (Cr), mean CT severity score (CT-ss), and O2 supportive therapy requirement were significantly higher in the mortality subgroup (p <0.05). Pleural effusion showed no significant correlation with short-term mortality. CT-ss of >11, in isolation or in combination with abovementioned prognosticators, was 64% or 81.4% sensitive, and 60% or of 78.6% specific, to predict mortality. Conclusions: Factors such as advanced age, underlying diseases such as diabetes, hypertension, and CKD, decreased air-room SPO2, and increased lymphocyte count, higher NLR, ESR, CRP, LDH, BS, BUN, and Cr level, as well as higher CT-ss and O2 supportive therapy, are all significantly correlated with higher mortality in ICU-admitted COVID-19 patients.

Adenocarcinoma in situ and minimally invasive adenocarcinoma in lungs of smokers: image feature differences from those in lungs of non-smokers

PurposeWe aimed to examine the characteristics of imaging findings of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) in the lungs of smokers compared with those of non-smokers.Materials and methodsWe included seven cases of AIS and 20 cases of MIA in lungs of smokers (pack-years ≥ 20) and the same number of cases of AIS and MIA in lungs of non-smokers (pack-years = 0). We compared the diameter of the entire lesion and solid component measured on computed tomography (CT) images, pathological size and invasive component diameter measured from pathological specimens, and CT values of the entire lesion and ground-glass opacity (GGO) portions between the smoker and non-smoker groups.ResultsThe diameters of AIS and MIA on CT images and pathological specimens of the smoker group were significantly larger than those of the non-smoker group (p = 0.036 and 0.008, respectively), whereas there was no significant difference in the diameter of the solid component on CT images or invasive component of pathological specimens between the two groups. Additionally, mean CT values of the entire lesion and GGO component of the lesions in the smoker group were significantly lower than those in the non-smoker group (p = 0.036 and 0.040, respectively).ConclusionAIS and MIA in smoker’s lung tended to have larger lesion diameter and lower internal CT values compared with lesions in non-smoker’s lung. This study calls an attention on smoking status in CT-based diagnosis for early stage adenocarcinoma.

Abstract 12314: Clinical Determinants of Low Attenuation Epicardial Adipose Tissue Volume in Type 2 Diabetes

Introduction: The accumulation of excess epicardial adipose tissue (EAT) is associated with the onset of specific heart failure phenotypes. Subsets of adipocytes in EAT produce an inflammatory secretome which alters the extracellular matrix of the epicardium and impairs myocardial contractility. Lipid-laden adipocytes have a low computed tomography (CT) attenuation and can be readily identified using cardiac CT. Objective: This study sought to identify the clinical and biomarker determinants of low attenuation EAT in participants with Type 2 diabetes (T2D) at risk of heart failure. Methods: Participants with T2D and non-diabetic controls were prospectively recruited to an observational multi-modality cardiovascular imaging study. Deep learning analytics (QFAT, Cedars-Sinai) measured EAT volume and CT attenuation from cardiac CT datasets. Adipose tissue with CT attenuation values of -90 to -190 Hounsfield Units (HU) were classified as low attenuation EAT regions. Comparison was made with anthropometric and blood biomarkers to evaluate determinants of low attenuation EAT. Results: Type 2 diabetic (n=151, median age 64 (59, 69) years, 65% male) and non-diabetic individuals (n=39, median age 59 (54, 66.5) years, 59% male) were recruited. Total EAT volume indexed to body surface area was 1.6-fold higher in diabetics (62.4 (49.1, 77.7) cm 3 /m 2 vs 38.8 (29.6, 51.9) cm 3 /m 2 , p <0.01) and mean CT attenuation was lower (-77.4 +/- 5.2 HU vs -70 +/- 5.4 HU, p <0.01). Larger indexed EAT volume was associated with a lower mean CT attenuation in all participants (r = -0.839, p <0.01). Multivariate analysis identified increasing age, white ethnicity and waist circumference as independent determinants of low attenuation EAT (adjusted R 2 = 0.2003, p <0.01). No association was found with dysglycemia (HbA1c, p = 0.2), dyslipidemia (Triglycerides, p = 0.1) and subclinical inflammation (neutrophil:lymphocyte ratio, p = 0.4). Conclusions: In patients with T2D, indexed EAT volumes are 1.6-fold higher with a lower mean CT attenuation. Age, white ethnicity and waist circumference are associated with low attenuation EAT. Prospective studies are required to determine whether interventions to reduce low attenuation EAT will prevent the onset of heart failure.

Age-related Changes in Computed Tomography Density of Thyroid Gland in Children: A Single-Center Retrospective Study in Northern China.

The thyroid gland normally presents as a hyperdense organ on noncontrast computed tomography (CT) in adults. The correlation between thyroid gland CT density and its functional status has been studied; however, little is known regarding its density in children with normal thyroid functions. We aimed to assess the correlation between thyroid gland CT density and age in children with normal thyroid functions. From April 2017 to March 2021, we enrolled 74 patients who had normal thyroid functions within 1 month before or after undergoing neck or cervical spine CT for trauma, neck masses, congenital diseases, and airway stenosis. Their CT images were retrospectively analyzed by 2 independent radiologists. Based on age, patients were divided into 4 groups: infant, preschool-aged, school-aged, and adolescence groups. Patients with thyroid gland hypodensity in the infant group (70%, 14 of 20) were significantly more numerous than those in preschool-aged (25%, 4 of 16), school-aged (20%, 5 of 25), and adolescence (15.4%, 2 of 13) groups (P = 0.007, 0.001, and 0.002, respectively, Fisher exact test). The mean CT density of the thyroid gland was also lower in the infant group compared with the densities in other age groups. There was a weak positive correlation between thyroid CT density and age (r = 0.264, P = 0.023, linear regression analysis). Thyroid CT density is related to age in children. The thyroid gland normally has a low density on noncontrast CT in most infants with normal thyroid function.

Establishment of diagnostic reference level for computed tomography of head pediatrics in Morocco: A pilot study

Pediatric patients are well documented to be at higher risk of developing radiation-induced cancer than the average adult. This pilot study aims to estimate the radiation doses to pediatric patients during head Computed Tomography (CT), in order to establish local Diagnostic Reference Level (DRL).Data from 300 pediatric head CT examinations from 6 public hospitals were analyzed. The age group concerned is 5–10 years. The CT facilities were 64, 16, 4 and dual slice type. CT data included scanner acquisition parameters, the number of series, use of the contrast medium, rotation time, slice thickness, as well as the displayed CT Dose Index (CTDIvol) and the Dose Length Product (DLP). The effective dose and DRL were evaluated using the formalism and conversion factor of the International Commission on Radiological Protection (ICRP).The overall mean CT dose per procedure from different facilities was 44,97 mGy, 883,67 mGy.cm and 2,81 mSv for CTDIvol, DLP and effective dose, respectively. The mean third quartile dose per head CT procedure from all facilities was 40,94 mGy and 969,90 mGy.cm cm for CTDI and DLP, in that order. These results proved that pediatric patients are exposed to unnecessary doses of radiation during CT examination in public healthcare institution of Morocco.The DRL obtained was slightly higher than those established in some countries. Pediatric radiation dose per procedure indicated a wide variation between various hospitals and even in the same hospital for different patients. This pilot study showed the need for practices unification and radiation doses optimization during CT scan acquisition for pediatric patients in radiology departments.

Evaluation of Apparent Noise on CT Images Using Moving Average Filters.

This study aims to devise a simple method for evaluating the magnitude of texture noise (apparent noise) observed on computed tomography (CT) images scanned at a low radiation dose and reconstructed using iterative reconstruction (IR) and deep learning reconstruction (DLR) algorithms, and to evaluate the apparent noise in CT images reconstructed using the filtered back projection (FBP), IR, and two types of DLR (AiCE Body and AiCE Body Sharp) algorithms. We set a square region of interest (ROI) on CT images of standard- and obese-sized low-contrast phantoms, slid different-sized moving average filters in the ROI vertically and horizontally in steps of 1 pixel, and calculated the standard deviation (SD) of the mean CT values for each filter size. The SD of the mean CT values was fitted with a curve inversely proportional to the filter size, and an apparent noise index was determined from the curve-fitting formula. The apparent noise index of AiCE Body Sharp images for a given mAs value was approximately 58, 23, and 18% lower than that of the FBP, AIDR 3D, and AiCE Body images, respectively. The apparent noise index was considered to reflect noise power spectrum values at lower spatial frequency. Moreover, the apparent noise index was inversely proportional to the square roots of the mAs values. Thus, the apparent noise index could be a useful indicator to quantify and compare texture noise on CT images obtained with different scan parameters and reconstruction algorithms.

Assessment and Prognostic Value of Immediate Changes in Post-Ablation Intratumor Density Heterogeneity of Pulmonary Tumors via Radiomics-Based Computed Tomography Features.

ObjectivesTo retrospectively observe the instantaneous changes in intratumor density heterogeneity after microwave ablation (MWA) of lung tumors and to determine their prognostic value in predicting treatment response and local tumor progression (LTP).MethodsPre- and post-MWA computed tomography (CT) images of 50 patients (37-males; 13-females; mean-age 65.9 ± 9.7y, 39 primary and 11 metastasis) were analyzed to evaluate changes in intratumor density. Global, regional, and local scale radiomics features were extracted to assess intratumor density heterogeneity. In four to six weeks, chest enhanced CT was used as the baseline evaluation of treatment response. The correlations between the parametric variation immediately after ablation and the visual score of ablation response (Rvisu) were analyzed by nonparametric Spearman correlation analysis. The 1-year LTP discrimination power was assessed using the area under the receiver operating characteristic (ROC) curves. A Cox proportional hazards regression model was used to identify the independent prognostic features.ResultsAlthough no significant volume changes were observed after ablation, the radiomics parameters changed in different directions and degrees. The mean intensity value from baseline CT image was 30.3 ± 23.2, and the post-MWA CT image was -60.9 ± 89.8. The ratio of values change was then calculated by a unified formulation. The largest increase (522.3%) was observed for cluster prominence, while the mean CT value showed the largest decline (321.4%). The pulmonary tumors had a mean diameter of 3.4 ± 0.8 cm. Complete ablation was documented in 36 patients. Significant correlations were observed between Rvisu and quantitative features. The highest correlations were observed for changes in local features after MWA, with r ranging from 0.594 to 0.782. LTP developed in 22 patients. The Cox regression model revealed Δcontrast% and response score as independent predictors (Δcontrast%: odds ratio [OR]=5.61, p=0.001; Rvisu: OR=1.73, p=0019). ROC curve analysis showed that Δcontrast% was a better predictor of 1-year LTP. with higher sensitivity (83.5% vs. 71.2%) and specificity (87.1% vs. 76.8%) than those for Rvisu.ConclusionsThe changes in intratumor density heterogeneity after MWA could be characterized by analysis of radiomics features. Real-time density changes could predict treatment response and LTP in patients with pulmonary tumors earlier, especially for tumors with larger diameters.

Efficacy of the spiral flow generating extended tube during paediatric CCTA

IntroductionTo compare the computed tomography (CT) number for paediatric cardiac computed tomography angiography (CCTA) and visualisation score of the three-dimensional (3D) images using the conventional T-shaped extended tube (T-tube) and spiral flow-generating extended tube (spiral-tube) connected between the contrast injector and cannula. MethodsIn total, 108 patients suspected to have congenital heart disease (CHD) were considered for inclusion. We utilised the T-tube for intravenous contrast and spiral-tube in 54 patients each. Observers individually inspected randomized volume rendering images of the internal thoracic artery, each acquired from the with or without spiral-tube groups, using a four-point scale. We compared the mean CT number of the ascending aorta (AAO) and pulmonary artery (PA), contrast noise ratio (CNR), CT number for the AAO and PA enhancement ratio, and the visualisation scores between the groups. ResultsThere were no significant differences in patient characteristics between the with or without spiral-tube groups (p > 0.05). The mean CT number ±standard deviation for the AAO and PA, and the CNR without or with spiral-tube groups were 441.2 ± 89.2 and 489.8 ± 86.1 HU for the AAO, 436.3 ± 100.6 and 475.3 ± 85.2 HU for the PA, and 9.5 ± 2.2 and 10.8 ± 2.4 for the CNR, respectively (p < 0.05). In the spiral-tube group, the CT number, CNR, and visualisations score of the 3D images were significantly higher for the AAO and PA than those in the T-tube group (p < 0.05). ConclusionThe spiral-tube proved to be beneficial in improving the CT number for the AAO and PA, CNR, and visualisation score compared with the conventional T-tube during paediatric CCTA. Implications for practiceThe spiral-tube may allow the visualisation of smaller blood vessels than those visualised by the conventional T-tube for paediatric patients in CCTA.

Values of Sinogram Affirmed Iterative Reconstruction Algorithm-Based Low-Dose Computed Tomography Imaging in Clinical Diagnosis of Cerebral Hemorrhage

In this study, the sinogram affirmed iterative reconstruction (SAFIRE) technology combined with low-dose computed tomography (CT) scanning technology was applied to scan patients with cerebral hemorrhage to evaluate the application value of this combined technology in the diagnosis of patients with cerebral hemorrhage. 132 patients with cerebral hemorrhage admitted to the hospital were selected randomly as the research objects in this study. According to the patients’ wishes, all of them were rolled into an experimental group and a control group. Besides, patients who were willing to use low-dose CT imaging scanning technology based on the SAFIRE algorithm were classified into the experimental group, and those who received simple low-dose CT scans were classified into the control group. Subjective score, objective score (mean CT value), image noise (SD), signal-to-noise ratio (SNR), and contrast-noise ratio (CNR) were used to analyze and compare the two groups of detection methods. The results showed the following: (1) The average result of CT images was 4.05 ± 0.28 points for the control group and 4.43 ± 0.59 points for the experimental group. According to the classification, the excellent and good rates of the experimental group (89.9%) were markedly higher than the rates of the control group (65.8%), with a statistically obvious difference ( P &lt; 0.05). (2) The standard deviation (SD), image signal-to-noise ratio (SNR), and contrast-noise ratio (CNR) results of gray matter, white matter, and cerebral hemorrhage lesions of patients from the experimental group were better than those of the control group, and the differences were statistically significant ( P &lt; 0.05). In conclusion, the image quality of a low-dose CT scan reconstructed by the SAFIRE algorithm was superior to that of a simple low-dose CT scan. In other words, the image quality of CT images could be guaranteed by the SAFIRE technology under the condition of reducing radiation dose. It enabled patients with cerebral hemorrhage to carry out diagnostic examinations with guaranteed accuracy under the risk of low radiation and provided better imaging services for patients with cerebral hemorrhage.

Correlation between fluoroscopy and tomographic aortic-root measurements in the decision of the transcatheter heart valve size in patients undergoing transcatheter aortic valve implantation

Abstract Introduction and hypothesis Transcatheter aortic valve implantation (TAVI) has become the standard treatment in intermediate and high-risk patients with high degree aortic stenosis (AS).(1–2) These has been also extended to low-risk and younger patients.(3–5) Besides the use of computed-tomography (CT) as diagnostic method to measure the aortic anatomy for transcatheter heart valve (THV) size decision and the radiation exposure (RE) during TAVI, younger patients are more exposed to radiation and contrast media (CM) complications due to a potentially second procedure.(6) Reducing RE and CM using only angiography aortic measurement could reduce the risk of RE and CM related complications without compromising the efficacy of the THV. We hypothesize that angiographic aortic root (AR) measure has good correlation with CT measure without compromising safety and efficacy of the THV. Methods Observational analysis: 1250 transfemoral TAVI patients with balloon or self-expandable valves were included. Aortic root CT measurement was done in all patients. AR measurement using Follow the right cup rule (7) was additionally done in 505 patients. Correlation between CT only (Group I n=745) versus CT and AR measurement (Group II n=505) was done. An inter and intraobserver validation analysis was done. Primary endpoint was VARC-2 device success. Secondary safety endpoints were composite of in-hospital and 30-days complications. Results Really good intra (0.86, p&amp;lt;0.001) and interobserver (0.81, p&amp;lt;0.001) correlation between CT (mean aortic diameter, distance between non (NC-HP) and left cusp hinge points (LC-HP) distance) and angiographic (LC-HP distance) measurements was observed. CT and AR measurement had a very good correlation between the two groups (CT mean aortic diameter vs CT NC-HP and LC-HP distance, 0.724 p&amp;lt;0.001; CT NC-HP and LC-HP distance vs angiographic NC-HP and LC-HP distance manual calibration 0.808 p&amp;lt;0.001; angiographic NC-HP and LC-HP distance manual calibration vs angiographic NC-HP and LC-HP distance automatic calibration 0.930 p&amp;lt;0.001). No differences in primary endpoint were observed between groups (device success Group I 98% vs Group II 99%, p 0.18). In-hospital complications were similar between two groups except in major bleeding (13% vs 19%, p 0.004), major vascular (10.9% vs 16.6%, p 0.004) and minor vascular (14% vs 21%, p 0.001) between group I and II respectively. Valve safety (86% vs 77%, p&amp;lt;0.001, OR 0.89, 95% CI 0.85–0.95) and clinical efficacy (84% vs 60.8%, p&amp;lt;0.001, OR 0.72, 95% CI 0.67–0.77) at 30 days were more common in group II. No difference in valve dysfunction was observed (Group I 10.3% vs Group II 7.3%, p 0.042, OR 1.41, 95% CI 0.97–2.05). Conclusions Compared to CT, AR measurement is a good option selecting THV size. No differences regarding device success and in-hospital and 30 days follow-up complications were observed. AR measurement could replace CT in specific cases. Funding Acknowledgement Type of funding sources: None. Angiographic and CT measurementsEndpoints

MA10.05 Potential of CT and PET-Based Radiomics for the Diagnosis of Lung Adenocarcinomas Indicated for Limited Resection

We previously developed radiomics technology using computed tomography (CT) to identify cases of preinvasive lung adenocarcinoma that may be indicated for limited resection. This study aimed to investigate whether the maximum standardized uptake value (SUVmax) on positron emission tomography (PET) has an add-on effect for this technology. This retrospective observational study was conducted at two medical centers. The resected pulmonary lesions were reviewed between April 2014 and March 2020. Patients with clinical stage IA lung adenocarcinomas were included. Thin-section CT images (less than 2.5 mm) were used to assess the clinical stage. For the image analysis algorithm of plain CT-based radiomics, we previously selected seven parameters: tumor volume (cm3), volume rate of the solid component (%solid; %), mean CT value (Hounsfield units), kurtosis, skewness, variance, and entropy. In this study, a new prediction model based on multiple logistic regression comprising eight parameters (CT＋PET-based radiomics) was generated, including SUVmax, after standardization to eliminate inter-facility bias. Next, stepwise variable selection was applied to the prediction model to evaluate whether SUVmax was a more important factor for identifying pathological preinvasive adenocarcinomas. A bootstrap method for randomized selection was used to assess the accuracy of the results. A total of 262 lung adenocarcinomas were categorized into the invasive group (n = 166 [63%]) or a preinvasive group (n = 96 [37%]), the latter of which comprised adenocarcinomas in situ (n = 32 [33%]) and minimally invasive adenocarcinomas (n = 64 [67%]). Before the surgery, the mean total tumor size of the invasive group (17.0 ± 6.5 mm) was significantly greater than that of the preinvasive group (13.9 ± 5.6 mm; p < 0.001). The pathological T factors were Tis (n = 32), T1mi (n = 64), T1a (n = 83), T1b (n = 66), and T1c (n = 17). Although spread through air spaces (STAS) was observed in 24 specimens (9.2%), five STAS-positive cases (5.2%) were noted in the preinvasive group. Upstaging was confirmed in one patient with lymph node-positive metastasis (N1) after pathological diagnosis. However, there were no cases of upstaging among the preinvasive tumors. Before standardization, the median SUVmax was 0.6 (interquartile range [IQR], 0.00–1.40) in the preinvasive group and 1.7 [IQR, 0.99–2.85]) in the invasive group (p < 0.001). After a stepwise method involving the eight factors, %solid (odds ratio [OR], 0.30; 95% confidence interval [CI], 0.20–0.46; p < 0.001) and entropy (OR, 0.46; 95% CI, 0.32–0.67; p < 0.001) were selected, but not SUVmax. The area under the curve was 0.83 (95% CI, 0.78–0.88). In the bootstrapping analysis, SUVmax was never selected as a key factor compared with the original parameters of CT-based radiomics. Even when the five STAS-positive cases in the preinvasive group were reclassified into the invasive group, SUVmax did not remain a key factor in the discrimination. In the identification of cases of preinvasive adenocarcinomas for which limited resection may be indicated, SUVmax did not increase the diagnostic efficacy of the original CT-based radiomics.

Influencia del realce de contraste al inyectar un medio de contraste en el brazo o la pierna en pacientes neonatos y lactantes durante la angiografía por cardiotomografía

Introduction and ObjectivesObtaining CCTA images with optimal injection location such as the arm or leg is important to avoid the artifacts caused by the CM. This study compares the computed tomography (CT) numbers and visualization scores of the three-dimensional (3D) images of the lumens of the blood vessels in the arm or leg during cardiac computed tomography angiography (CCTA) in neonatal and infant patients. Patients or Materials and MethodsBetween January 2017 and January 2020, 253 consecutive patients were considered for inclusion. We used the estimated propensity scores as a function of the demographic data, including age, body weight, and injection location (right or left side) in the arm (n=58) and leg (n=58) of neonatal and infant patients. We compared the mean CT numbers of the pulmonary artery, ascending aorta, and left superior vena cava; contrast–noise ratios (CNR); and visualization scores between the arm and leg as the injection locations. ResultsThe mean CT numbers during CCTA for the arm and leg were 479.4 and 461.3 HU in the ascending aorta, 464.2 and 448.1 HU in the pulmonary artery, and 232.8 and 220.1 HU in the left superior vena cava, respectively. The mean image noise (SD) and CNR values, respectively, were 38.9 HU and 12.1 for the arm as the injection location and 39.1 HU and 12.3 for the leg as the injection location. The median visualization scores of volume rendering of the 3D images were 3.0 and 3.0 for the arm and leg injection sites, respectively. There were no significant differences in the mean CT numbers of the ascending aorta, pulmonary artery, and left superior vena cava; SD value; CNR; and visualization scores between the arm and leg injection locations. ConclusionsThe CT numbers of the lumen of the blood vessel and visualization scores of the 3D images of the arm and leg injection locations are equal during CCTA in neonatal and infant patients with congenital heart disease.

Chest CT Scan Findings in Symptomatic Patients Infected with COVID-19 in Norvic International Hospital, Nepal

Background Coronavirus disease (COVID-19) is the recent global health emergency making it crucial for rapid diagnosis and intervention. Computed tomography (CT) is important for screening, diagnosis and evaluating severity and disease progress.&#x0D; Objective To assess the CT changes in COVID patients and study its relationship with various factors.&#x0D; Method A retrospective study was conducted at Norvic International hospital from August 2020 to November 2020 among RT-PCR positive symptomatic COVID cases who had positive CT changes. CT imaging data were analyzed by radiology expertise. Statistical analysis was carried out with the help of SPSS 16.&#x0D; Result Out of 120 patients, 75% were males and mean age was 54.70±15.56 years. The mean CT severity score was 18.35±6.87. Pure ground glass opacities was seen in 74(61.7%), reticulations 89(74.2%) and crazy-paving pattern 28(23.3%). CT scans with bilateral 118(98.3%) and peripheral involvement 109(90.8%) in all five lobes. CT- severity score was positively correlated with oxygen and mechanical ventilation requirement (P-value &lt; 0.05 and 0.011 respectively).&#x0D; Conclusion CT findings including pure ground glass opacities, reticulations, bilateral and peripheral involvement involving all five lobes were more frequent. Our data suggest that CT-severity score significantly correlates with oxygen and mechanical ventilation requirements.

A Triphasic Split-bolus Contrast Injection Protocol for Artery-vein Separation During Pulmonary Computed Tomographic Angiography.

Accurate artery-vein separation on pulmonary computed tomographic (CT) angiography is desirable for preoperative 3-dimensional image simulation, while using a minimal amount of contrast medium. This study aimed to verify whether a split-bolus contrast enhancement protocol with test-bolus tracking would provide contrast differentiation between the pulmonary arteries (PA) and pulmonary veins (PV) during high-pitch single-pass CT angiography. Fifty patients underwent pulmonary CT angiography with a triphasic split-bolus injection protocol with the main bolus of contrast medium for 6 seconds, followed by a subsequent bolus of 20% diluted contrast medium/80% saline for another 6 seconds and a 5-second saline chaser. The single-scan timing was individually tailored to the peak enhancement at the left atrium, that is, the pulmonary-venous dominant phase, by monitoring a time-enhancement curve with test bolus. Time-enhancement curves of the test bolus demonstrated that the interval times between the peak enhancements at the PA and PV were ~6 seconds. For contrast enhancement image analyses with our protocol, the attenuation measurements at the main PA and left atrium were performed. The mean (SD) CT numbers were 246.4 (50.0) HU at the main PA, and 410.8 (59.0) HU at the left atrium. The mean difference in the CT numbers was 164.4 HU (95% confidence interval: 149.2-179.6, P <0.001) between the main PA and left atrium. Our contrast enhancement protocol for high-pitch single-pass pulmonary CT angiography could provide the desired artery-vein separation while maintaining adequate attenuations of the pulmonary vasculature.

Method for determining slice sensitivity profile of iterative reconstruction CT images using low-contrast sphere phantom.

A novel method for measuring the slice sensitivity profile (SSP) of computed tomography (CT) images reconstructed using an iterative reconstruction (IR) algorithm is proposed herein. A phantom that included a low-contrast spherical object was scanned and consecutive cross-sectional images were reconstructed. The mean CT values in a region including the sphere were measured for all images and plotted as a function of slice position along the longitudinal [Formula: see text] direction to yield a mean CT value profile [Formula: see text]. Next, we numerically generated an object function corresponding to the sphere and obtained the mean CT value profile [Formula: see text]. Subsequently, the SSP was modeled as a product of the Gaussian and cosine functions. We convolved [Formula: see text] with the modeled SSP to obtain [Formula: see text]. The difference between [Formula: see text] and [Formula: see text] was evaluated using the root mean square error (RMSE), which was minimized via optimization of the SSP model parameters. To validate the methodology, we first used filtered back projection (FBP) images to compare the SSPs determined using the proposed and standard coin methods. Subsequently, the proposed method was applied to measure the SSPs of four types of IR algorithms in two scanners. The SSPs of the FBP images determined using the proposed and coin methods showed good agreement. Additionally, in the SSP measurements using the proposed method, [Formula: see text] agreed well with [Formula: see text] for every IR algorithm. The RMSEs for all measurements were less than 0.7 HU, indicating the accuracy of the SSPs. Thus, the proposed method is effective for obtaining valid SSPs.

Ultrasonic Heating Detects Lipiodol Deposition within Liver Tumors after Transarterial Embolization: An In Vivo Approach.

Simple SummaryThe accumulation of Lipiodol (ethiodized oil) after transarterial embolization is known to reflect tumor necrosis. In general, the treatment effect is evaluated by computed tomography; there has been no development in imaging modalities for several decades. A new technique, ultrasonic heating, can differentiate biological tissues based on the fact that tissues’ characteristic sound velocity varies depending on the temperature. This technique could have the potential to evaluate treatment effect after transarterial embolization as an alternative to computed tomography.Computed tomography (CT) is the standard method to evaluate Lipiodol deposition after transarterial embolization (TAE) for a long period. However, iodine but not Lipiodol can be observed on CT. A minimally invasive other method to detect Lipiodol has been needed to evaluate accurate evaluation after procedure. The purpose of this study was to evaluate the efficacy of using the rate of change in sound velocity caused by ultrasonic heating to reflect Lipiodol accumulation after TAE in a rat liver tumor model. We analyzed the association of this developed technique with CT images and histological findings. Eight rats bearing N1S1 cells were prepared. After confirmation of tumor development in a rat liver, Lipiodol was injected via the hepatic artery. Seven days after TAE, CT scan and sound velocity changes caused by ultrasonic heating were measured, and then the rats were sacrificed. An ultrasonic pulse-echo method was used to measure the sound velocity. The temperature coefficient of the sound velocity in each treated tumor was evaluated and compared with the mean CT value and the histological Lipiodol accumulation ratio. Pearson’s correlation coefficients were calculated to assess the correlation between the measured values. The correlation coefficient (r) of the mean CT value and histological Lipiodol accumulation ratio was 0.835 (p = 0.010), which was considered statistically significant. Also, those of the temperature coefficient of the sound velocity and the histological Lipiodol accumulation ratio were statistically significant (r = 0.804; p = 0.016). To our knowledge, this is the first study that reported the efficacy of ultrasonic heating to detect Lipiodol accumulation in rat liver tumors after TAE. Our results suggest that the rate of change in sound velocity caused by ultrasonic heating can be used to evaluate Lipiodol accumulation in liver tumors after TAE, and thus could represent an alternative to CT in this application. This new innovative technique is easy to treat and less invasive in terms of avoiding radiation compared with CT.

Changes in the Mean Intrahepatic Target Computed Tomography Attenuation Value During Treatment May Be a Useful New Predictor of the Post-progression Survival Associated with Lenvatinib Treatment.

Objective The relationship between the prognosis and magnitude of a decrease in tumor blood flow according to estimated tumor differentiation remains unclear. This study investigated the relationship between reductions in the rate of mean computed tomography (CT) attenuation values and the clinical prognosis. Methods We evaluated 63 consecutive patients who received lenvatinib treatment for unresectable hepatocellular carcinoma (HCC). The oncological aggressiveness of the tumors was estimated using classification by dynamic CT enhancement patterns. The utility of changes in mean CT attenuation values of intra-hepatic targets during treatment to estimate the prognosis was investigated by calculating the progression-free survival (PFS) and post-progression survival (PPS). A multivariate analysis was used to identify potential confounders for the survival after progression during lenvatinib therapy. Results The rate of decrease in the mean CT attenuation value gradually increased according to the degree of deterioration in estimated tumor differentiation, and the rate of a decrease in attenuation ≥40% showed a tendency to increase (p=0.064). This trend was reflected by a better objective response in oncological aggressiveness heterogeneous enhancement patterns (Type-3 and Type-4) than a homogeneous enhancement pattern (Type-2) (83% vs. 56% of modified Response Evaluation Criteria in Solid Tumors). This resulted in a similar PFS between the groups (p=0.773), whereas the PPS was significantly worse when the rate of decrease in the attenuation value was ≥40% (p=0.012). A multivariate analysis confirmed that a rate of decease in attenuation value ≥40% was a poor prognostic factor for the PPS (hazard ratio, 2.993; 95% confidence interval, 1.196-7.490; p=0.019). Conclusion A rate of decrease in attenuation ≥40% may reflect a good response of a highly malignant tumor to lenvatinib. Therefore, this value may have utility as a surrogate marker for estimating the oncological aggressiveness of tumors and their associated prognosis.

Computed Tomography-Determined Body Composition Abnormalities Usefully Predict Long-term Mortality in Patients With Liver Cirrhosis.

We evaluated the prognostic impacts of body composition components measured by computed tomography (CT) in patients with liver cirrhosis. A total of 160 cirrhotic patients who underwent CT and hepatic venous pressure gradient measurements were retrospectively enrolled. Cross-sectional areas of skeletal muscle, visceral and subcutaneous fat, and mean CT attenuation of trabecular bone of the fourth lumbar vertebral level (L4HU) were measured. Multivariate analysis showed model for end-stage liver disease score [hazard ratio (HR), 1.086; 95% confidence interval (CI), 1.020-1.156; P = 0.010], hepatic venous pressure gradient (HR, 1.076; 95% CI, 1.021-1.135; P = 0.006), sarcopenia (HR, 1.890; 95% CI, 1.032-3.462; P = 0.039), and L4HU (HR, 1.960 for L4HU <145 Hounsfield units; 95% CI, 1.094-3.512; P = 0.024) were independently associated with long-term mortality. In patients with decompensated cirrhosis, subcutaneous adipose tissue index was the only independent predictor (HR, 0.984; 95% CI, 0.969-0.999; P = 0.039). Body composition abnormalities determined by CT are associated with long-term prognosis in cirrhotic patients.

Computed tomography measured psoas muscle attenuation predicts mortality after transcatheter aortic valve implantation.

The aim of this study was to determine if computed tomography (CT) psoas muscular attenuation measurements may predict all-cause mortality in patients undergoing TAVI. Ninety-four consecutive patients undergoing TAVI were analysed. The CT axial slice at the level of the fourth lumbar vertebra was selected. The psoas muscle areas were manually contoured. The circumferential surface area (CSA) of both psoas muscles was determined by selecting the voxels with attenuation values, ranging from 0 to 100 Hounsfield Units (HU). The mean CT attenuation coefficient of the psoas muscle (Psoas mean HU) was measured. The muscle was subdivided into a low-density muscle (LDM) (0-29 HU) and high-density muscle (HDM) (30-100 HU) portion. The HDM/LDM ratio was calculated. We searched for a correlation between HDM/LDM, CSA LDM (%), Psoas mean HU and all-cause mortality. The mean age was 81.2 ± 7.5 years. Thirty patients had adverse outcome (all-cause mortality). Compared with patients with the lowest CSA LDM (%), patients in the third and second tertiles had an increased hazard ratio for mortality (2.871; 95% confidence interval 0.880-9.371 and 5.044; 95% confidence interval 1.641-15.795, respectively) in a multivariable model with EuroSCORE II, Barthel frailty index and CSA LDM (%) (P = 0.231, 0.097 and 0.019, respectively). HDM/LDM and Psoas mean HU (as continuous variable) were also independent predictors of all-cause mortality (P = 0.019, P = 0.013, respectively). CSA LDM (%), Psoas mean HU and HDM/LDM are independent and incremental predictors of all-cause mortality in patients undergoing TAVI.