Diagnostic Utility of Restriction Spectrum Imaging in Head and Neck Tumors: A Pilot Study.

OBJECTIVE: Imaging is crucial in the assessment of head and neck cancers for site, extension, and enlarged lymph nodes. Restriction spectrum imaging (RSI) is a new diffusion-weighted magnetic resonance imaging (MRI) technique that enhances the ability to differentiate aggressive cancer from low-grade or benign tumors and helps guide treatment and biopsy. Its contribution to imaging of brain and prostate tumors has been previously published. However, there are no prior studies using RSI sequence in head and neck tumors. The purpose of this study was to evaluate the feasibility of performing RSI in head and neck cancer. METHODS: An additional RSI sequence was added in the routine MRI neck protocol for 13 patients diagnosed with head and neck cancer between November 2018 and April 2019. Restriction spectrum imaging sequence was performed with b values of 0, 500, 1500, and 3000 s/mm 2 and 29 directions on 1.5T magnetic resonance scanners.Diffusion-weighted imaging (DWI) images and RSI images were compared according to their ability to detect the primary malignancy and possible metastatic lymph nodes. RESULTS: In 71% of the patients, RSI outperformed DWI in detecting the primary malignancy and possible metastatic lymph nodes, whereas in the remaining cases, the 2 were comparable. In 66% of the patients, RSI detected malignant lymph nodes that DWI/apparent diffusion coefficient failed to detect. CONCLUSIONS: This is the first study of RSI in head and neck imaging and showed its superiority over the conventional DWI sequence. Because of its ability to differentiate benign and malignant lymph nodes in some cases, the addition of RSI to routine head and neck MRI should be considered.

Subacute neurological sequelae in mild COVID-19 outpatients.

Introduction: Neurological aspect of COVID-19 is less understood compared to its respiratory and systemic effects. We aimed to define subacute neurological sequelae in patients who recovered from mild COVID-19. Materials and Methods: This study enrolled long COVID patients who had mild infection, were non-hospitalized, and admitted to our hospital with neurological complaints occurring after COVID-19. The evaluation included detailed history of the symptoms, neurological examination, blood tests and necessary investigations relevant to their personal medical situation, and also a retrospective inquiry about their respiratory and neurological status during the acute phase of infection. Descriptive statistical measures, Chi-square and Student's t-test were utilized. Result: We identified 50 patients (29F/21M) with a mean age of 36.9 ± 1.6 (mean ± SEM). The average time from COVID-19 to admission was 99 days(min-max= 15-247). Most frequent neurological complaints were headache (42%) and cognitive dysfunction (42%). Sleep disturbance (36%), prolonged anosmia (30%), prolonged ageusia (22%), fatigue (22%), and dizziness (8%) followed. Most patients with headache experienced headache also as an acute manifestation of COVID-19 (p= 0.02). Acute-stage sleep disorders were found to be more associated with subacute cognitive symptoms than other central symptoms (p= 0.008). The most common neurological symptom in the acute phase was headache (74%). Six patients, despite the absence of any acute-stage neurological symptoms, presented with emergence of subacute neurological sequela. There were only five patients with pulmonary involvement during the acute stage, who were not different from the rest of the cohort in terms of neurological sequelae. There was no increase of inflammatory markers in the blood tests at the subacute stage, or no association of the symptoms to biochemical parameters. Conclusions: This study gives a description of neurological sequelae of mild COVID-19 at the subacute stage, in a relatively young group, and reveals that cognitive disturbances, as well as headache, are quite frequent.

Assessment of Plasma-Free Cortisol Concentrations by LC-MS/MS in Patients with Autonomous Cortisol Secretion.

Autonomous cortisol secretion (ACS) of an adrenal incidentaloma (AI) is associated with mild cortisol excess that could result in poor metabolic and cardiovascular outcomes. The biological activity of glucocorticoids depends on the unbound, free fraction. We aimed to evaluate plasma free cortisol (FC) concentrations in patients with ACS in this cross-sectional study. One hundred and ten AI patients in 3 groups; non-functioning (NFA, n=33), possible ACS (n=65), ACS (n=12) were enrolled. Following measurements were conducted: Clinical data and total serum cortisol (TC), plasma corticotrophin (ACTH), serum dehydroepiandrosterone sulfate (DHEA-S), cortisol after 1 mg dexamethasone by both immunoassay and LC-MS/MS (DexF), serum corticosteroid binding globulin (CBG), plasma dexamethasone concentration [DEX] and plasma FC by LC-MS/MS. Patients with ACS featured an unfavorable metabolic profile. Plasma [DEX] and serum CBG levels were similar between groups. Plasma FC was significantly higher in ACS when compared to NFA and possible ACS groups p<0.05 and p<0.01, respectively. In multiple regression analysis DexF (beta=0.402, p<0.001) and CBG (beta=-0.257, p=0.03) remained as the independent predictors of plasma FC while age, sex, BMI, smoking habit, and existing cardiovascular disease did not make a significant contribution to the regression model. In conclusion, the magnitude of cortisol excess in ACS could lead to increased plasma FC concentrations. Further studies in AI patients are needed to demonstrate whether any alterations of cortisol affinity for CBG exist and to establish whether plasma FC concentrations predict the unfavorable metabolic profile in ACS.

How high is the inter-observer reproducibility in the LIRADS reporting system?

PURPOSE: To investigate the reproducibility of LIRADS v2014 and contribute to its widespread use in clinical practice. MATERIAL AND METHODS: This retrospective, single-centre study was conducted between January 2010 and October 2015. A total of 132 patients who had dynamic magnetic resonance imaging (MRI)/computed tomography (CT) images in the Picture Archiving and Communication Systems (PACS) with liver nodule were included in the study, 37 of whom had histopathology results. Five radiologists who participated in the study, interpreted liver nodules independently on different PACS stations according to the LIRADS reporting system and its main parameters. RESULTS: We determined that level of inter-observer agreement in the LR-1, LR-5, and LR-5V categories was higher than in the LR-2, LR-3, and LR-4 categories (κ = 0.522, 0.442, and 0.600 in the LR-1, LR-5, and LR-5V categories, respectively; κ = 0.082, 0.298, and 0.143 in the LR-2, LR-3, and LR-4 categories, respectively). The parameter that we observed to have the highest level of inter-observer agreement was venous thrombus (κ = 0.600). CONCLUSIONS: Our study showed that LIRADS achieves an acceptable inter-observer reproducibility in terms of clinical practice although it is insufficient at intermediate risk levels. We think that the prevalence of its use will be further increased with training related to the subject and the assignment of numerical values that express the probability of malignancy for each category and including the ancillary features in the algorithm according to clearer rules.

Foreign body aspiration in a pregnant woman: successfully removed roasted chickpea.

Foreign body aspiration is a serious health problem in all age groups, and in pregnancy it may cause serious complications for the fetus as well as the pregnant woman. Here we present our case of a 36 years old 22 weeks pregnant woman, accidentally aspirating roasted chickpea upon laughing. She had the complaints of coughing and shortness of breath on admission, bronchoscopy was performed, and the roasted chickpea blocking the entrance of right lower lobe bronchus was removed without any complications. For foreign body aspiration in pregnancy, bronchoscopy is a rather safer procedure when performed by an experienced team.

Autonomous cortisol secretion in adrenal incidentalomas and increased visceral fat accumulation during follow-up.

OBJECTIVE: Autonomous cortisol secretion of adrenal incidentalomas (AIs) is associated with poor cardiovascular outcome. Because centripetal obesity is a cardiovascular risk factor, we aimed to investigate whether autonomous cortisol secretion is associated with increased visceral fat accumulation. DESIGN: Retrospective cohort study. PATIENTS: Patients with AIs who attended for follow-up between January 2014 and December 2016 were evaluated. Autonomous cortisol secretion was diagnosed when 1 mg overnight dexamethasone (post-DST) cortisol was >50 nmol/L at baseline and follow-up. Follow-up duration was 34 (12-105) months. Thirty patients with nonfunctioning AIs and 44 patients with autonomous cortisol secretion were included. Adrenalectomy was performed in five patients. Six patients with Cushing's syndrome were also recruited. MEASUREMENTS: Hormonal evaluation and assessment of total (T), visceral (V) and subcutaneous (S) fat area by computed tomography and calculation of V:S and V:T ratios at baseline and follow-up. RESULTS: V, V:S and V:T increased (P<.001 for each comparison, Wilcoxon signed rank test for repeated measures) in patients with autonomous cortisol secretion while did not change significantly in patients with nonfunctioning adenomas. Linear regression models including post-DST cortisol, gender, concomitant treatments and follow-up duration showed that both baseline and follow-up DST significantly predicted Δ(V:S) and Δ(V:T) (P<.01 for all models). CONCLUSIONS: In patients with AIs, a post-DST cortisol >50 nmol/L at both baseline and follow-up, was associated with a significant increase in visceral fat after a follow-up duration of ~3 years. This may be of importance to explain the link between autonomous cortisol secretion and poor cardiovascular outcome.

Utility of chest CT after a chest X-ray in patients presenting to the ED with non-traumatic thoracic emergencies.

BACKGROUND: Chest radiography is the initial choice for thoracic imaging. However, the wide availability of computed tomography (CT) has led to a substantial increase in its use in the emergency department (ED). We evaluated the utility of chest CT after a chest X-ray in patients presenting to the ED with non-traumatic thoracic emergencies, and determined if the diagnosis and management decision changed after CT. METHODS: The study enrolled 500 consecutive patients with both chest X-rays and CT who presented to the ED with non-traumatic complaints. Chest X-rays and CT images obtained within 12h before any definitive treatment were randomly evaluated in consensus by two radiologists blinded to the clinical information. RESULTS: The chest X-ray and CT image findings were concordant in 49.2% of the 500 patients and this concordance was negatively correlated with patient age. Leading diagnosis and management decisions based on the chest radiograph changed after CT in 35.4% of the study group and this finding was also correlated with age. In 55% of 205 patients, pneumonic infiltrations were undiagnosed with radiography. Pulmonary edema was the most specific (93.3%) and sensitive (85.4%) radiography finding. Posteroanterior chest radiographs taken in the upright position had higher concordance with CT than anteroposterior (AP) radiographs taken in the supine position. CONCLUSIONS: Chest CT may be an appropriate imaging choice in patients presenting to the ED for non-traumatic reasons, particularly for elderly patients and when the radiograph is taken with the AP technique in a supine position.

The Effect of Rapid Antigen Detection Test on Antibiotic Prescription Decision of Clinicians and Reducing Antibiotic Costs in Children with Acute Pharyngitis.

We aimed to investigate the effect of rapid antigen detection test (RADT) in the diagnosis of streptococcal pharyngitis, its impact on antibiotic prescription decision of pediatricians and influence on reduction of antibiotic treatment costs in children with pharyngitis. The study group consisted of 223 patients who were diagnosed with pharyngitis by pediatricians. The sensitivity and specificity of RADT were 92.1% (95% Cl: 78.6-98.3%) and 97.3% (95% Cl: 93.8-99.1%), respectively. In the first assessment, before performing RADT, pediatricians decided to prescribe antibiotics for 178 (79.8%) patients with pharyngitis. After learning RADT results, pediatricians finally decided to prescribe antibiotics for 83 (37.2%) patients with pharyngitis, and antibiotic prescription decreased by 42.6%. Antibiotic costs in non-Group A streptococcus pharyngitis, Group A streptococcus pharyngitis and all subjects groups decreased by 80.8%, 48%, and 76.4%, respectively. Performing RADT in children with pharyngitis has an important impact on treatment decision of clinicians, reduction of unnecessary antibiotic prescriptions and antibiotic costs.

Many Faces of Adrenal Lesions in a Large Patient Cohort: What Has Changed Over the Last Two Decades?

OBJECTIVE: To review the presentation characteristics, clinical and hormonal evaluations, and histopathological results of patients with adrenal lesions over a 21-year period and evaluate the changes across the two decades. METHODS: This single-center, retrospective study included 1003 patients with adrenal lesions who presented to our department between 2000 and 2021. Clinical, metabolic, hormonal, radiological, and pathological data of the patients were collected. RESULTS: Forty-seven percent of the lesions were non-functioning adrenal adenomas. Possible autonomous and autonomous cortisol secretion were detected in 22.2% of the patients. The percentages of the patients diagnosed with pheochromocytoma, primary hyperaldosteronism, adrenal Cushing syndrome, adrenocortical carcinoma, and adrenal metastasis were 7.4%, 4.8%, 4.7%, 0.9%, and 5.6%, respectively. Adrenalectomy was performed in 31.3% of the patients. Functional adrenal lesions were the leading cause of surgery (46.5%), followed by large size and/or suspicious imaging features (38.6%). Among the patients referred to surgery due to large size (≥6 cm), the diagnosis in 19% was metastasis, and in 12.1%, it was primary adrenocortical carcinoma. In patients with adrenal lesions with a size of 4-6 cm and suspicious imaging properties, the rates of metastasis and primary adrenocortical carcinoma were 44.4% and 4.8%, respectively. From the first to the second decade, major differences in presentation characteristics were increased detection of bilateral lesions and increased prevalence of possible autonomous and autonomous cortisol secretion. CONCLUSIONS: Adrenal lesions are common in the adult population, and while it is important to avoid overtreatment, hormone secretion, and malignancy should not be overlooked.

Headache and cognitive disturbance correlate with ganglion cell layer thickness in patients who recovered from COVID-19.

BACKGROUND: Retinal abnormalities are being increasingly reported in COVID-19, in addition to the well-known symptoms of this disease accounting for the neurological involvement. In this study, we aimed to investigate whether ganglion cell layer thickness (GCLT) was different in recovered COVID-19 patients compared to controls in the subacute stage and to determine whether it correlated with COVID-19-related neurological symptoms or pneumonia. METHODS: This study involved 40 patients who had recovered from COVID-19 and 40 age- and sex-matched healthy controls. All the participants underwent ophthalmological examination, spectral domain optical coherence tomography and neurological examination. The clinical and biochemical properties of the patients were noted and their correlations with GCLT were sought. RESULTS: The duration after COVID-19 infection was 113 ± 62 (mean ± SD) days. At this subacute stage, there was no significant difference between the GCLT measurements of the COVID-19 patients and the controls (14 ± 4.0 µm [median ± IQR] vs 16 ± 4.8 µm, respectively). When we analyzed the relationships with neurological symptoms in the patient group, we found that patients with cognitive symptoms had lower GCLT values compared to those without (13 ± 3 µm vs. 16 ± 4 µm, respectively; p = 0.002). Patients who suffered headache during the acute infection also had lower GCLT values compared to those without (14 ± 4 µm vs. 18 ± 5 µm, respectively; p = 0.015). The GCLT values did not differ significantly with respect to anosmia, ageusia, sleep disturbances, having had COVID-19 pneumonia, or smoking status. Age, duration after COVID-19, and blood levels of thyroid stimulating hormone, glucose, vitamin D and vitamin B12 were not in correlation with GCLT in our study. CONCLUSION: Our findings highlight an association between GCLT values and neurological symptoms such as cognitive disturbance (brain fog) and headache in patients who had recovered after non-severe COVID-19 infection. Neuroretinal involvement by SARS-CoV2 might be linked to central neurological symptoms. The patients with lower GCLT values may benefit from close monitoring for neurological problems.

Effect of bivalirudin on neointimal hyperplasia and endothelial proliferation in rabbit.

BACKGROUND: The aim of this study was to investigate the effects of bivalirudin on endothelial cell proliferation and neointimal hyperplasia in a rabbit carotid artery model. METHODS: "New Zealand rabbits (n = 12)" weighing 2-3 kg were randomly divided into two groups. Arteriotomy was performed to the rabbit carotid artery and closed with continuous suture technique. Group B (n = 6) as a control group received 150 U/kg heparin sodium; however, group A (n = 6) was given 0.75 mg/kg bivalirudin i.v. bolus and infusion 1.75 mg/kg/hour (B01AE06-Bivalirudin 250 mg) during perioperation period. At the end of the 28th day, the carotid artery segment was excised and evaluated histologically. RESULTS: All histological and immune staining analyzes were performed by two blind researchers in the treatment of rabbits. In the control group rabbit carotid artery sections, tunica intima was observed to thicken. In the bivalirudin group, intimal hyperplasia was less observed compared to the control group. No significant difference was observed between groups in tunica media thickness. Lumen diameter and lumen area were found to be wider in the experimental group. P value was found to be less than 0.05. CONCLUSION: Our study demonstrates that bivalirudin significantly affects and prevents neointimal hyperplasia and endothelial cell proliferation.

The effect of environmental diesel exhaust pollution on SARS-CoV-2 infection: The mechanism of pulmonary ground glass opacity.

Diesel exhaust particles (DEP) are the major components of atmospheric particulate matter (PM) and chronic exposure is recognized to enhance respiratory system complications. Although the spread of SARS-CoV-2 was found to be associated with the PMs, the mechanism by which exposure to DEP increases the risk of SARS-CoV-2 infection is still under discussion. However, diesel fine PM (dPM) elevate the probability of SARS-CoV-2 infection, as it coincides with the increase in the number of ACE2 receptors. Expression of ACE2 and its colocalized activator, transmembrane protease serine 2 (TMPRSS2) facilitate the entry of SARS-CoV-2 into the alveolar epithelial cells exposed to dPM. Thus, the coexistence of PM and SARS-CoV-2 in the environment augments inflammation and exacerbates lung damage. Increased TGF-ß1 expression due to DEP accompanies the proliferation of the extracellular matrix. In this case, "multifocal ground-glass opacity" (GGO) in a CT scan is an indication of a cytokine storm and severe pneumonia in COVID-19.

Evaluation of 99mTechnetium-Vancomycin Imaging Potential in Experimental Rat Model for the Diagnosis of Infective Endocarditis.

BACKGROUND: Infective endocarditis (IE) is an infection of the heart's endocardial surface. In recent years, nuclear imaging methods have gained importance in the diagnosis of IE. The present study aims to investigate the imaging potential of 99mTc-labeled vancomycin (99mTc-Vancomycin) as a new agent that would enable the diagnosis of IE in its early stages when it is difficult to diagnose or has small vegetation in the experimental rat model. METHODS: 99mTc-Vancomycin scintigraphy was evaluated for its accumulation in IE with Staphylococcus aureus performed in an experimental rat model. Serial planar scintigraphic and biodistribution analysis of infected vegetations are compared to rats with sterile vegetations. The heart was identified as an infected organ, the liver was identified as a non-infected organ and the heart/liver uptake ratio (T / NT ratio) was compared between infective endocarditis and sterile endocarditis groups. RESULTS: Planar scintigrams (in vivo measurements) showed more uptake in the heart of rats in the infective endocarditis group compared to the uptake in the heart of rats in the sterile endocarditis group, but this difference was not statistically significant (p>0.05). From the ex vivo measurements, the 99mTc-Vancomycin heart uptake increased significantly (p = 0.016), liver uptake was significantly decreased (p = 0.045) and the T/NT ratio was significantly higher (p = 0.014) in the infective endocarditis group compared to the sterile endocarditis group. CONCLUSION: In this experimental study, 99mTc-Vancomycin scintigraphy ensured the detection of ex vivo infected tissue in a rat model of IE. In addition, the absence of significant 99mTc-Vancomycin uptake in the sterile endocarditis group indicates that this agent targeted the infected tissue instead of the sterile inflammatory tissue. Finally, this agent should also be evaluated with animal- specific imaging devices.

CHAOS Challenge - combined (CT-MR) healthy abdominal organ segmentation.

Segmentation of abdominal organs has been a comprehensive, yet unresolved, research field for many years. In the last decade, intensive developments in deep learning (DL) introduced new state-of-the-art segmentation systems. Despite outperforming the overall accuracy of existing systems, the effects of DL model properties and parameters on the performance are hard to interpret. This makes comparative analysis a necessary tool towards interpretable studies and systems. Moreover, the performance of DL for emerging learning approaches such as cross-modality and multi-modal semantic segmentation tasks has been rarely discussed. In order to expand the knowledge on these topics, the CHAOS - Combined (CT-MR) Healthy Abdominal Organ Segmentation challenge was organized in conjunction with the IEEE International Symposium on Biomedical Imaging (ISBI), 2019, in Venice, Italy. Abdominal organ segmentation from routine acquisitions plays an important role in several clinical applications, such as pre-surgical planning or morphological and volumetric follow-ups for various diseases. These applications require a certain level of performance on a diverse set of metrics such as maximum symmetric surface distance (MSSD) to determine surgical error-margin or overlap errors for tracking size and shape differences. Previous abdomen related challenges are mainly focused on tumor/lesion detection and/or classification with a single modality. Conversely, CHAOS provides both abdominal CT and MR data from healthy subjects for single and multiple abdominal organ segmentation. Five different but complementary tasks were designed to analyze the capabilities of participating approaches from multiple perspectives. The results were investigated thoroughly, compared with manual annotations and interactive methods. The analysis shows that the performance of DL models for single modality (CT / MR) can show reliable volumetric analysis performance (DICE: 0.98 ± 0.00 / 0.95 ± 0.01), but the best MSSD performance remains limited (21.89 ± 13.94 / 20.85 ± 10.63 mm). The performances of participating models decrease dramatically for cross-modality tasks both for the liver (DICE: 0.88 ± 0.15 MSSD: 36.33 ± 21.97 mm). Despite contrary examples on different applications, multi-tasking DL models designed to segment all organs are observed to perform worse compared to organ-specific ones (performance drop around 5%). Nevertheless, some of the successful models show better performance with their multi-organ versions. We conclude that the exploration of those pros and cons in both single vs multi-organ and cross-modality segmentations is poised to have an impact on further research for developing effective algorithms that would support real-world clinical applications. Finally, having more than 1500 participants and receiving more than 550 submissions, another important contribution of this study is the analysis on shortcomings of challenge organizations such as the effects of multiple submissions and peeking phenomenon.

Reversible 3D compression of segmented medical volumes: usability analysis for teleradiology and storage.

BACKGROUND: DICOM standard does not have modules that provide the possibilities of two-dimensional Presentation States to three-dimensional (3D). Once the final 3D rendering is obtained, only video/image exporting or snapshots can be used. To increase the utility of 3D Presentation States in clinical practice and teleradiology, the storing and transferring the segmentation results, obtained after tedious procedures, can be very effective. PURPOSE: To propose a strategy for preserving interaction and mobility of visualizations for teleradiology by storing and transferring only binary segmented data, which is effectively compressed by modern adaptive and context-based reversible methods. MATERIAL AND METHODS: A diverse set of segmented data, which include four abdominal organs (liver, spleen, right, and left kidneys) from 20 T1-DUAL and 20 T2-SPIR MRI, liver from 20 CT, and abdominal aorta with aneurysms (AAA) from 19 computed tomography-angiography datasets, are collected. Each organ is segmented manually by expert physicians, and binary volumes are created. The well-established reversible binary compression methods PNG, JPEG-LS, JPEG-XR, CCITT-G4, LZW, JBIG2, and ZIP are applied to medical datasets. Recently proposed context-based (3D-RLE) and adaptive (ABIC) algorithms are also employed. The performance assessment has been presented in terms of the compression ratio that is a universal compression metric. RESULTS: Reversible compression of binary volumes results with substantial decreases in file size such as 254 to 2.14 MB for CT-AAA, 56.7 to 0.3 MB for CT-liver. Moreover, compared to the performance of well-established methods (i.e., mean 76.14%), CR is observed to be increased significantly for all segmented organs from both CT and MRI datasets when ABIC (95.49%) and 3D-RLE (94.98%) are utilized. The hypothesis is that morphological coherence of scanning procedure and adaptation between the segmented organs, that is, bi-level images, contributes to compression performance. Although the performance of well-established techniques is satisfactory, the sensitivity of ABIC to modality type and the advantage of 3D-RLE when the spatial coherence between the adjacent slices are high results with up to 10 times more CR performance. CONCLUSION: Adaptive and context-based compression strategies allow effective storage and transfer of segmented binary data, which can be used to re-produce visualizations for better teleradiology practices preserving all interaction mechanisms.

COVID-19 S: A new proposal for diagnosis and structured reporting of COVID-19 on computed tomography imaging.

PURPOSE: Because of the widespread use of CT in the diagnosis of COVID 19, indeterminate presentations such as single, few or unilateral lesions amount to a considerable number. We aimed to develop a new classification and structured reporting system on CT imaging (COVID-19 S) that would facilitate the diagnosis of COVID-19 in the most accurate way. METHODS: Our retrospective cohort included 803 patients with a chest CT scan upon suspicion of COVID 19. The patients' history, physical examination, CT findings, RT PCR, and other laboratory test results were reviewed, and a final diagnosis was made as COVID 19 or non-COVID 19. Chest CT scans were classified according to the COVID 19 S CT diagnosis criteria. Cohen's kappa analysis was used. RESULTS: Final clinical diagnosis was COVID-19 in 98 patients (12%). According to the COVID-19 S CT diagnosis criteria, the number of patients in the normal, compatible with COVID 19, indeterminate and alternative diagnosis groups were 581 (72.3%), 97 (12.1%), 16 (2.0%) and 109 (13.6%). When the indeterminate group was combined with the group compatible with COVID 19, the sensitivity and specificity of COVID-19 S were 99.0% and 87.1%, with 85.8% positive predictive value (PPV) and 99.1% negative predictive value (NPV). When the indeterminate group was combined with the alternative diagnosis group, the sensitivity and specificity of COVID-19 S were 93.9% and 96.0%, with 94.8% PPV and 95.2% NPV. CONCLUSION: COVID-19 S CT classification system may meet the needs of radiologists in distinguishing COVID-19 from pneumonia of other etiologies and help optimize patient management and disease control in this pandemic by the use of structured reporting.

Comparison of semi-automatic and deep learning-based automatic methods for liver segmentation in living liver transplant donors.

PURPOSE: To compare the accuracy and repeatability of emerging machine learning based (i.e. deep) automatic segmentation algorithms with those of well-established semi-automatic (interactive) methods for determining liver volume in living liver transplant donors at computerized tomography (CT) imaging. METHODS: A total of 12 (6 semi-, 6 full-automatic) methods are evaluated. The semi-automatic segmentation algorithms are based on both traditional iterative models including watershed, fast marching, region growing, active contours and modern techniques including robust statistical segmenter and super-pixels. These methods entail some sort of interaction mechanism such as placing initialization seeds on images or determining a parameter range. The automatic methods are based on deep learning and they include three framework templates (DeepMedic, NiftyNet and U-Net) the first two of which are applied with default parameter sets and the last two involve adapted novel model designs. For 20 living donors (6 training and 12 test datasets), a group of imaging scientists and radiologists created ground truths by performing manual segmentations on contrast material-enhanced CT images. Each segmentation is evaluated using five metrics (i.e. volume overlap and relative volume errors, average/RMS/maximum symmetrical surface distances). The results are mapped to a scoring system and a final grade is calculated by taking their average. Accuracy and repeatability were evaluated using slice by slice comparisons and volumetric analysis. Diversity and complementarity are observed through heatmaps. Majority voting and Simultaneous Truth and Performance Level Estimation (STAPLE) algorithms are utilized to obtain the fusion of the individual results. RESULTS: The top four methods are determined to be automatic deep models having 79.63, 79.46 and 77.15 and 74.50 scores. Intra-user score is determined as 95.14. Overall, deep automatic segmentation outperformed interactive techniques on all metrics. The mean volume of liver of ground truth is found to be 1409.93 mL ± 271.28 mL, while it is calculated as 1342.21 mL ± 231.24 mL using automatic and 1201.26 mL ± 258.13 mL using interactive methods, showing higher accuracy and less variation on behalf of automatic methods. The qualitative analysis of segmentation results showed significant diversity and complementarity enabling the idea of using ensembles to obtain superior results. The fusion of automatic methods reached 83.87 with majority voting and 86.20 using STAPLE that are only slightly less than fusion of all methods that achieved 86.70 (majority voting) and 88.74 (STAPLE). CONCLUSION: Use of the new deep learning based automatic segmentation algorithms substantially increases the accuracy and repeatability for segmentation and volumetric measurements of liver. Fusion of automatic methods based on ensemble approaches exhibits best results almost without any additional time cost due to potential parallel execution of multiple models.

A heart atlas for breast radiation therapy and the influence of delination education on both intra and interobserver variability.

PURPOSE: We developed a heart atlas for breast radiation therapy and evaluated the influence of education on intra and inter-observer similarity, and cardiac dose reporting. MATERIALS AND METHODS: The data of 16 left breast cancer patients were analyzed. Eight observers delineated heart and cardiac subunits [left (LCA) and right (RCA) coronary arteries, left anterior descending artery (LAD), bilateral atrium and ventricles] before the education. A radiologist and radiation oncologist developed the atlas and delineated the gold standard (GS) volumes. Observers repeated the delineation after education. RT plans were made for pre/post-atlas contours. The similarity was assessed by Dice (DSC) and Jaccard (JSC) similarity coefficient indices. The absolute difference rate was calculated for the dose analysis. RESULTS: The inter-observer similarity increased in heart and all subunits. The intra-observer similarity showed a heterogeneous distribution. The absolute difference rate in dose reporting was statistically significant for the bilateral atrium, right ventricle, LAD, LCA + LAD, RCA's maximum doses (p < 0.05). The maximum dose reporting differences from the GS decreased from 16.9 to 8.9% for LAD (p = 0.011); from 14.8 to 9.3% for LCA + LAD (p = 0.010). CONCLUSION: The cardiac atlas reduces the intra-interobserver differences and improves dose reporting consistency. The first intra-observer similarity analysis was made in our study and revealed the need for repeated education to increase the consistency.

Evaluation of ocular pulse amplitude in patients with carotid artery stenosis using the Pascal dynamic contour tonometer.

BACKGROUND: To evaluate ocular pulse amplitude (OPA) in patients with carotid artery stenosis (CAS) using the Pascal dynamic contour tonometer (DCT). METHODS: Consecutive patients who underwent ultrasound Doppler examination of the carotid artery for the suspicion of CAS were prospectively enrolled in the study. Each patient underwent a complete ocular examination. OPA was measured using Pascal DCT. The participants were divided into four groups according to the degree of CAS: Group 1 (no occlusion, control group), Group 2 (mild occlusion: < 50 per cent), Group 3 (moderate occlusion: 50-69 per cent), and Group 4 (severe occlusion: ≥ 70 per cent). RESULTS: A total of 161 eyes of 81 patients were included in the study. Of the 81 patients, 50 (61.7 per cent) were male, and 31 (38.3 per cent) were female. The mean age was 66.6 ± 12.3 years (range, 20-91 years). Mean OPA values were found to be 2.68 ± 0.97 mmHg in Group 1 (n = 64 eyes), 2.62 ± 0.83 mmHg in Group 2 (n = 49 eyes), 2.30 ± 0.97 mmHg in Group 3 (n = 27 eyes) and 1.66 ± 0.59 mmHg in Group 4 (n = 21 eyes). There was no statistically significant difference in mean OPA levels between Group 1 and Group 2 (p = 0.73). However, statistically significant differences were found between the other groups when they were compared with each other (Groups 1 and 3, p = 0.02; Groups 1 and 4, p < 0.001; Groups 2 and 3, p = 0.02; Groups 2 and 4, p < 0.001; Groups 3 and 4, p = 0.002). CONCLUSION: OPA decreases in patients with moderate to severe CAS. OPA measurement with Pascal DCT can be used as a screening test for CAS.

Clinical and hemodynamic profiles of elderly patients with pulmonary arterial hypertension: a single center, prospective study.

BACKGROUNDS: Pulmonary arterial hypertension (PAH) was previously considered an illness that affects mostly the young, but now it is also increasingly recognized in the elderly. The aim of this study was to compare the features of elderly versus younger patients diagnosed with PAH, and to define the prognostic factors which affect their long-term survival. METHODS: In this prospective, single center study, the clinical, echocardiographic, hemodynamic characteristics, and the outcomes of younger (18-65 years) and elderly (≥ 65 years) patients with definitive diagnosis of precapillary PAH were compared. RESULTS: A total of 119 patients were analyzed in this study; 43 were elderly (mean age: 71.5 ± 5.5 years), while 76 were non-elderly (mean age 44.5 ± 15.2 years). During the mean follow-up duration of 26.8 ± 25.0 months, 43 deaths occurred, 17 of which were among the elderly group, with 28 among non-elderly group. Comparison of baseline parameters showed that 6 min walking distance, hemoglobin levels, pulmonary artery pressures and pulmonary vascular resistance were significantly lower; and estimated glomerular filtration rate, body mass index, E/e' and pulmonary capillary wedge pressure were significantly higher in the elderly group than in the younger group. Survival analysis demonstrated that the independent predictors of death were tricuspid plane annular systolic excursion (TAPSE; HR: 1.272, 95% CI: 1.079-1.499, P = 0.004) and uric acid (HR: 1.291, 95% CI: 1.042-1.600, P = 0.019) in the elderly group. In contrast, in the non-elderly group, higher brain natriuretic peptide (HR: 1.002, 95% CI: 1.001-1.004, P < 0.001) and higher right atrial pressure (HR: 1.128, 95% CI: 1.026-1.241, P = 0.013) values were the only parameters associated with mortality. CONCLUSIONS: Our data suggest that elderly PAH patients have a unique clinical and hemodynamic profile, with totally different prognostic markers compared to younger PAH patients.