Pandemics and Health Crisis in ICU of Two Greek Public Hospitals.

The purpose of this study was to collect and analyze information on the operating conditions of intensive care units of Greek Public Hospital during the COVID-19 pandemic. The need to improve the Greek healthcare sector was widely recognized prior to and was clearly demonstrated during the pandemic when the Greek medical and nursing staff dealt with numerous problems on a daily basis. Two questionnaires were developed for data collection. One addressed issues faced by the ICUs Head Nurses and the other by the hospitals' Biomedical Engineers. The questionnaires aimed at identifying needs and weaknesses in workflow, ergonomics, care delivery protocols, system maintenance and repair. The findings from the ICUs of two reference COVID-19 Greek hospitals are reported here. Significant differences were observed in the biomedical engineering services but both hospitals encountered similar ergonomic issues. Data collection from other Greek hospitals is in progress. Final results will be used as a guide to develop novel, time and cost-efficient strategies in ICU care delivery.

Tumor Size Measurements for Predicting Hodgkin's and Non-Hodgkin's Lymphoma Response to Treatment.

The purpose of this study was to investigate the value of tumor size measurements as prognostic indicators of treatment outcome of Hodgkin's and Non-Hodgkin's lymphomas. 18F-FDG PET/CT exams before and after treatment were analyzed and metabolic and anatomic parameters-tumor maximum diameter, tumor maximum area, tumor volume, and maximum standardized uptake value (SUVmax)-were determined manually by an expert and automatically by a computer algorithm on PET and CT images. Results showed that the computer algorithm measurements did not correlate well with the expert's standard maximum tumor diameter measurements but yielded better three dimensional metrics that could have clinical value. SUVmax was the strongest prognostic indicator of the clinical outcome after treatment, followed by the automated metabolic tumor volume measurements and the expert's metabolic maximum diameter measurements. Anatomic tumor measurements had poor prognostic value. Metabolic volume measurements, although promising, did not significantly surpass current standard of practice, but automated measurements offered a significant advantage in terms of time and effort and minimized biases and variances in the PET measurements. Overall, considering the limited value of tumor size in predicting response to treatment, a paradigm shift seems necessary in order to identify robust prognostic markers in PET/CT; radiomics, namely combinations of anatomy, metabolism, and imaging, may be an option.

Clinical Perspectives for 18F-FDG PET Imaging in Pediatric Oncology: Μetabolic Tumor Volume and Radiomics.

Pediatric cancer, although rare, requires the most optimized treatment approach to obtain high survival rates and minimize serious long-term side effects in early adulthood. 18F-FDG PET/CT is most helpful and widely used in staging, recurrence detection, and response assessment in pediatric oncology. The well-known 18F-FDG PET metabolic indices of metabolic tumor volume (MTV) and tumor lesion glycolysis (TLG) have already revealed an independent significant prognostic value for survival in oncologic patients, although the corresponding cut-off values remain study-dependent and not validated for use in clinical practice. Advanced tumor "radiomic" analysis sheds new light into these indices. Numerous patterns of texture 18F-FDG uptake features can be extracted from segmented PET tumor images due to new powerful computational systems supporting complex "deep learning" algorithms. This high number of "quantitative" tumor imaging data, although not decrypted in their majority and once standardized for the different imaging systems and segmentation methods, could be used for the development of new "clinical" models for specific cancer types and, more interestingly, for specific age groups. In addition, data from novel techniques of tumor genome analysis could reveal new genes as biomarkers for prognosis and/or targeted therapies in childhood malignancies. Therefore, this ever-growing information of "radiogenomics", in which the underlying tumor "genetic profile" could be expressed in the tumor-imaging signature of "radiomics", possibly represents the next model for precision medicine in pediatric cancer management. This paper reviews 18F-FDG PET image segmentation methods as applied to pediatric sarcomas and lymphomas and summarizes reported findings on the values of metabolic and radiomic features in the assessment of these pediatric tumors.

Association of antipsychotic use with raised eosinophil count.

The current study aimed to assess the possibility of an association between first and second generation antipsychotic medication and raised eosinophil count. A total of 22 in-patients at the psychiatric unit of the University General Hospital 'Attikon', a tertiary hospital, were included in the present study. Patients had received antipsychotic monotherapy and did not have any co-morbidities or require additional treatments. Patients were monitored weekly and their eosinophil count was assessed. One-way ANOVA and summary measures analysis were applied to study the effect of time and medication type on the absolute eosinophil concentration (or relative percentage) for each patient. The differences in mean eosinophil concentrations or relative percentage by patient and time were also assessed. An increase in the absolute concentration and the relative percentage of eosinophils over time was observed in patients receiving Olanzapine, Haloperidol and Aripiprazole. However, there was no difference between individual medications. In conclusion, antipsychotics may be associated with increased eosinophil count over time; however, larger studies involving more patients and a longer follow-up are required to reach a definitive conclusion.

Personalized Biomechanic Models: Factors Affecting Shoulder Motion.

The design and development of personalized prosthetics or rehabilitation treatments of extremities disorders relies on accurate mathematical models. The effect of various parameters on shoulder joint mobility was investigated in order to develop more accurate, adaptive models. Active and passive abduction at the frontal plane and active and passive flexion at the sagittal plane were studied on two different age groups. Results showed statistically significant differences in shoulder movement between the two groups. The range of movement decreased considerably in older volunteers while no significant differences were observed within the same age group. Active and passive movements differed significantly while flexion was easier to perform than abduction. Movement was independent of weight, height, BMI, gender, and handedness. Exercise had a significant positive impact on the elderly and may counterbalance age effects. Age and exercise parameters should be included in prosthetics modeling and rehabilitation to improve and personalize care.

18 F-FDG PET/CT brain glucose metabolism as a marker of different types of depression comorbidity in chronic heart failure patients with impaired systolic function.

AIMS: Depression is an important issue in heart failure (HF). The study investigated whole-brain and regional brain glucose metabolism in HF patients and its association with depression comorbidity. METHODS AND RESULTS: Twenty-nine hospitalized patients with symptomatic systolic HF (left ventricular ejection fraction <40%), New York Heart Association (NYHA) class II-IV and mean age of 55.5 ± 12.0 years, had psychometric questionnaires before discharge and an 18 F-FDG PET/CT brain scan after discharge. Semi-automated image analysis was performed on all cases and 30 matched controls. The metabolic parameter mean standardized uptake value (SUVmean ) was calculated for the whole brain and three brain regions implicated in depression pathogenesis. A standardized SUVmean was also estimated by dividing regional brain SUVmean with whole-brain SUVmean . Cases had lower average whole-brain SUVmean (3.90 ± 1.49 vs. 5.10 ± 1.35, P = 0.001) and average regional brain SUVmean (4.57 ± 2.31 vs. 9.96 ± 3.58, P < 0.001) compared to controls. Whole-brain SUVmean had a significant correlation with patient age, NYHA class, diabetes, creatinine levels, depression, and cognitive impairment. Regional brain SUVmean was correlated with whole-brain SUVmean and depression. The standardized SUVmean , in particular, was found to be a robust index that could differentiate HF patients with 'epiphenomenal' (>0.93) or 'real' (≤0.93) depression. CONCLUSION: Heart failure patients with more severe disease showed whole-brain and regional brain hypometabolism in 18 F-FDG PET/CT. Depressed HF patients (Beck Depression Inventory score >13) exhibited different metabolic patterns that could be used to differentiate between 'epiphenomenal' and 'real' depression. Namely, presence of whole-brain hypometabolism suggested 'epiphenomenal' depression, whereas absence suggested 'real' depression. Presence of significant relative regional brain hypometabolism enhanced the likelihood of 'real' depression diagnosis.

Prevalence, distribution and clinical significance of joints, muscles and bones in sarcoidosis: an 18F-FDG-PET/CT study.

OBJECTIVES: In Sarcoidosis joints-muscles-bones (JMBs) localizations are of the least common. 18F-FDG-PET/CT imaging revolutionized detection of JMBs involvement by adding metabolic activity information and allowing for a comprehensive, whole-body mapping of the disease. AIM AND METHODS: This study investigated prevalence, distribution, and clinical significance of JMBs sarcoidosis in 195 consecutive patients that underwent 18F-FDG PET/CT examination. RESULTS: Joint and bone involvement were encountered in 15% of patients with a mean of the maximum-standardized-uptake-value (SUVmax) of 6.1. Most common location was the axial skeleton. Hypercalciuria was significantly more frequent in patients with osseous involvement (p = 0.003). Muscle activity (SUVmax = 2.4) was encountered in 20% of the patients, most frequently in treatment-naïve (p = 0.02). The muscles of the lower extremities were affected the most. Muscle and bone localization coexist in 50% of the cases. JMBs disease was almost asymptomatic, not related to chronicity but to pulmonary, nodal, and systemic disease. Long-term follow-up and treatment response of affected patients confirmed sarcoidosis. CONCLUSION: 18F-FDG-PET/CT revealed JMBs localizations and coexistence with other organ sites supporting the concept that sarcoidosis is a systemic disease. By allowing an integrative interpretation of multi-organ involvement in the context of a pattern highly suggestive of sarcoidosis, it strongly keeps-off the diagnosis of malignancy.

Emerging phenotypes of sarcoidosis based on 18F-FDG PET/CT: a hierarchical cluster analysis.

Objectives: In sarcoidosis, the definition of organ involvement with traditional means appears laborious and somewhat controversial, and phenotyping by the above overlapping. 18F-FDG PET/CT defines disease extent by activity more precisely, and may result in a better understanding of sarcoidosis disease behavior and phenotypes expression. We hypothesized that 18F-FDG PET/CT could add in the phenotyping of sarcoidosis patients by unveiling in detail sites of involvement even in clinically and physiologically silent disease.Methods: This study was designed to investigate the role of 18F-FDG PET/CT in phenotyping sarcoidosis using cluster analysis by adding this new means in the routine work-up of 195 sarcoidosis patients of a single academic center.Results: 18F-FDG PET/CT succeeded to identify despite the random distribution of the disease, an ordered stratification into 4 phenotypes: I) thoracic nodal hilar-mediastinal, II) thoracic nodal hilar-mediastinal and lungs, III) an extended thoracic and extra-thoracic only nodal phenotype including inguinal-abdominal-supraclavicular stations, and IV) all the above plus systemic organs and tissues such as muscles-bones-spleen and skin.Conclusion: Though further studies are necessary to confirm findings as patterns of disease behavior; the proposed phenotypes may prove useful in the design of future studies with homogeneous cohorts facilitating in sarcoidosis patients a personalized medicine approach.

18F-FDG PET/CT in Pulmonary Sarcoidosis:Quantifying Inflammation by the TLG index.

Objectives: In sarcoidosis progressive pulmonary disease affects prognosis. Pulmonary disease activity estimated by classic means poorly predicts severity and progressiveness. 18F-fluoro-2-deoxyglucose-positron-emission-tomography computed-tomography (18F-FDG-PET/CT) estimates pulmonary activity by inflammatory-cells metabolism. We aimed to investigate pulmonary sarcoidosis by 18F-FDG-PET/CT and evaluate the role of total-lesion-glycolysis (TLG) value, as an index quantifying the whole burden of lung inflammation.Methods: This is a retrospective study of sequentially gathered data. From a Greek cohort of 195 sarcoidosis-patients, 87 were identified with lung increased 18F-FDG uptake and further studied.Results: Visualizing lung by 18F-FDG-PET/CT identified new imaging patterns and revealed activity in all Scadding stages. Ever-smokers presented significantly higher TLG and lower DLCO compared to never-smokers. However, TLG value did not correlate with functional indices and did not differ between symptomatic and non-symptomatic patients. Among treatment-naïve patients, TLG did not differ significantly in those requiring therapy compared to those remained off.Conclusion: 18F-FDG PET/CT improved imaging and detection of pulmonary involvement and through TLG value revealed the deleterious smoking effect. The fact that TLG neither detected patients with clinical symptoms and functional impairment nor identified those requiring treatment once again confirms that in pulmonary sarcoidosis the link between activity, severity and decision to treat still eludes us.

A Longitudinal Study of Alterations of S100B, sRAGE and Fas Ligand in Association to Olanzapine Medication in a Sample of First Episode Patients with Schizophrenia.

BACKGROUND & OBJECTIVE: Neuroinflammation has been proposed as a major mechanism in schizophrenic disorder. Specifically, an increase in the inflammatory response in the central nervous system is capable of activating microglial cells, leading to the release of pro-inflammatory cytokines and thus activating apoptotic signaling. An increase in apoptosis may underlie a potential role of immune neuropathology in the etiopathogenesis of schizophrenia and specifically, the onset of the disorder. We analyzed in whole blood, levels of S100B, the receptor for advanced glycation end products (RAGE) and the apoptotic marker Fas Ligand in a sample of 13 first episode of schizophrenia twice at baseline before the initiation of any antipsychotic medication (A) and 6 weeks later following an antipsychotic monotherapy with olanzapine (B) and in a sample of 10 healthy controls. The S100B, RAGE and Fas Ligand showed statistically significant differences before and after treatment; the S100B measurements yielded a p-value of 0.004 while the soluble RAGE and Fas Ligand measurements yielded a p=0.03, and p=0.04 respectively. The differences between cases and controls were not statistically significant for all measurements, with the only exception being the S100B values where both samples A and B showed significantly higher values than the controls with p=8.5x10-8 and p=2.9x10-10 respectively. CONCLUSION: The levels of S100B, RAGE, and Fas Ligand of drug-naive first episode psychosis patients with schizophrenia were significantly higher than that of the same medicated first episode psychosis patients, indicating that an increase of apoptotic signaling is present at the onset of schizophrenia and is also associated with treatment progress.

The effect of patient anxiety and depression on motion during myocardial perfusion SPECT imaging.

BACKGROUND: Patient motion during myocardial perfusion SPECT imaging (MPI) may be triggered by a patient's physical and/or psychological discomfort. The aim of this study was to investigate the impact of state anxiety (patient's reaction to exam-related stress), trait anxiety (patient's personality characteristic) and depression on patient motion during MPI. METHODS: All patients that underwent MPI in our department in a six-month period were prospectively enrolled. One hundred eighty-three patients (45 females; 138 males) filled in the State-Trait Anxiety Inventory (STAI) and the Beck Depression Inventory (BDI), along with a short questionnaire regarding their age, height and weight, level of education in years, occupation, and marital status. Cardiovascular and other co-morbidity factors were also evaluated. Through inspection of raw data on cinematic display, the presence or absence of patient motion was registered and classified into mild, moderate and severe, for both phases involved in image acquisition. RESULTS: The correlation of patient motion in the stress and delay phases of MPI and each of the other variables was investigated and the corresponding Pearson's coefficients of association were calculated. The anxiety-motion (r = 0.43, P < 0.0001) and depression-motion (r = 0.32, P < 0.0001) correlation results were moderately strong and statistically significant for the female but not the male patients. All the other variables did not demonstrate any association with motion in MPI, except a weak correlation between age and motion in females (r = 0.23, P < 0.001). CONCLUSIONS: The relationship between anxiety-motion and depression-motion identified in female patients represents the first supporting evidence of psychological discomfort as predisposing factor for patient motion during MPI.

Association between bone scintigraphy features of spinal degeneration and anthropometric and demographic variables.

BACKGROUND AND OBJECTIVES: Bone scintigraphy is a molecular imaging technique routinely used for the evaluation of benign and malignant bone abnormalities. This study aimed at evaluating spinal degenerative changes detected by bone scintigraphy and determining associations between image features and patients' anthropometric and demographic variables. MATERIAL AND METHOD: In a cross-sectional study, 64 men and 52 women underwent bone scintigraphy. Experts identified all image regions suggesting degenerative joint disease (DJD) and classified region intensity on a 3-point scale. Image characteristics were correlated to the patients' body mass index (BMI), age, weight, height, activity level, and sex. Data analysis included descriptive statistics and association coefficients. RESULTS: DJD was found in 53 patients (46%). In men, there was weak but statistically significant correlation between DJD and activity level, and DJD and age, but not BMI or weight. In women, only a weak, not statistically significant, linear correlation was found between DJD and BMI, and DJD and weight. CONCLUSION: Molecular imaging with bone scintigraphy showed that spinal degenerations are associated with different anthropometric and demographic features in men and women. Interestingly, no association was found between DJD and increased body weight in men while a weak association may exist in women. The results prompt for additional studies to better determine the risk factors for DJD and low back pain in male and female patients. LEVEL OF EVIDENCE: Diagnostic study, Level II (retrospective study).

Recurrent thyroid cancer diagnosis: ROC study of the effect of a high-resolution head and neck 18F-FDG PET/CT scan.

RATIONALE AND OBJECTIVES: (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) has demonstrated significant value in the evaluation of patients with indication of recurrent thyroid cancer with negative conventional workup. The hypothesis of this study was that the addition of a dedicated, high-resolution head and neck scan (HNS) to the standard whole-body scan (WBS) improves the accuracy of the detection and diagnosis of recurrent thyroid cancer. MATERIALS AND METHODS: Forty-three consecutive patients suspected for recurrent thyroid cancer, as indicated by increased tumor markers, prospectively underwent a WBS and a HNS with (18)F-FDG PET/CT. The patients were followed up to establish ground truth. A receiver operator characteristic (ROC) study with two observers was conducted to evaluate the impact of the additional HNS on the detection and diagnosis of recurrent thyroid cancer. Indices of performance included the area under the ROC curve (AUC), the number of detected abnormal foci, and the size of the detected foci without and with the HNS images. RESULTS: ROC results showed that the addition of the HNS to the standard WBS increased the average AUC index of performance from 0.69 to 0.96, a statistically significant difference with a confidence interval (CI) of -0.33 to -0.19. Diagnosis was also improved with the average AUC increasing from 0.79 to 0.87 but differences were not statistically significant (CI, -0.19 to 0.04). Interreader agreement was "good" in the detection task and "excellent" in the diagnostic task. The addition of the HNS increased the number of detected foci in the positive patients by an average of 37%, whereas false-positive detections in the negative patients increased by an average of 10%. Reported average maximum lesion size also increased with the HNS addition by an average of 11%. CONCLUSIONS: The addition of a high-resolution HNS to the standard whole-body PET/CT imaging improves readers' performance in the detection and diagnosis of recurrent thyroid cancer and could greatly benefit patient care.

Choosing a radiology workstation: technical and clinical considerations.

Choosing a workstation for daily use in the interpretation of digital radiologic images can be a daunting task. There are numerous products available on the market, but differentiating among them and deciding on what is best for a particular environment can be confusing and frustrating. There is no "one-size-fits-all" workstation, so users must consider a variety of factors when choosing a workstation. This review summarizes the critical elements in a radiology workstation and the characteristics one should be aware of and look for in the selection of a workstation. Issues pertaining to both hardware and software aspects of medical workstations, including interface design, are reviewed, particularly as they may affect the interpretation process.

Computerized analysis of tissue density effect on missed cancer detection in digital mammography.

This paper presents a study of the analysis of breast density in missed cancer cases and the effect of tissue density on cancer detection. A total of 100 missed cancer cases were collected. The breast density tissue was segmented with a statistical-based method. A set of tests was then applied to examine: (1) the differences in density between the mammograms at the detected stage and that at missed stage; (2) the density difference between the cancerous mammograms and their contra-lateral normal mammograms in the missed cancer cases; (3) the effect of breast density on CAD cancer detection. The results demonstrate that breast density is an important factor affecting not only radiologist's reading but also CAD performance. In order to improve early detection of breast cancer, a special effort should be directed to the high dense breast cases in CAD system design.

High-performance wavelet compression for mammography: localization response operating characteristic evaluation.

PURPOSE: To evaluate the accuracy of a visually lossless, image-adaptive, wavelet-based compression method for achievement of high compression rates at mammography. MATERIALS AND METHODS: The study was approved by the institutional review board of the University of South Florida as a research study with existing medical records and was exempt from individual patient consent requirements. Patient identifiers were obliterated from all images. The study was HIPAA compliant. An algorithm based on scale-specific quantization of biorthogonal wavelet coefficients was developed for the compression of digitized mammograms with high spatial and dynamic resolution. The method was applied to 500 normal and abnormal mammograms from 278 patients who were 32-85 years old, 85 of whom had biopsy-proved cancer. Film images were digitized with a charge-coupled device-based digitizer. The original and compressed reconstructed images were evaluated in a localization response operating characteristic experiment involving three radiologists with 2-10 years of experience in reading mammograms. RESULTS: Compression rates in the range of 14:1 to 2051:1 were achieved, and the rates were dependent on the degree of parenchymal density and the type of breast structure. Ranges of the area under the receiver operating characteristic curve were 0.70-0.83 and 0.72-0.86 for original and compressed reconstructed mammograms, respectively. Ranges of the area under the localization response operating characteristic curve were 0.39-0.65 and 0.43-0.71 for original and compressed reconstructed mammograms, respectively. The localization accuracy increased an average of 6% (0.04 of 0.67) with the compressed mammograms. Localization performance differences were statistically significant with P = .05 and favored interpretation with the wavelet-compressed reconstructed images. CONCLUSION: The tested wavelet-based compression method proved to be an accurate approach for digitized mammography and yielded visually lossless high-rate compression and improved tumor localization.

Breast Tissue Density and CAD Cancer Detection in Digital Mammography.

This study is part of the research of improving early detection of breast cancer in screening mammograms by focusing on computerized analysis and detection of cancers missed by radiologists. It is directed to the analysis of breast density in missed cancer cases and the effect of tissue density on cancer detection. A total of 100 missed cancer cases were collected which were used to generate three different datasets including mammograms with missed cancer, mammograms with screening-detected cancer and normal mammograms. A statistical-based method was applied to segment the breast density tissue. The percentage of the segmented density tissue area out of the whole breast area is calculated as the index of breast density. A set of tests was applied to examine (1) the differences in density between the mammograms at the detected stage and that at missed stage, (2) the density difference between the normal mammograms and the cancerous mammograms; (3) the effect of breast density on CAD cancer detection. The results demonstrate that (1) no significant difference in breast density between the detected and missed stages; (2) the density of cancerous mammograms is significantly higher than normal mammograms; (3) similar to mammogram screening by radiologists, the lesions occurred in dense breasts are more likely to be missed in CAD detection especially at their early stage.

Clinical evaluation of a new digitizing device for improved film mammography.

RATIONALE AND OBJECTIVES: The study was designed to evaluate a new digitizing device, the iView (Maxxvision, LLC, Gainesville, FL), which aims to replace the magnifying glass in mammography with real-time film digitization, display, and processing. MATERIALS AND METHODS: A receiver operating characteristic (ROC) experiment was performed with 5 certified mammographers and 114 mammograms that were read with and without the iView. A satisfaction survey was also conducted on the system's features and usefulness. RESULTS: Data analysis suggested that (1) Cancer sensitivity could improve with the use of the iView system. ROC area differences showed improvements from 2% to 24% although these were not always statistically significant. At a false positive rate of 0.2, the true positive rate increased up to 60% depending on the set of cases and the observer's experience. (2) Specificity could also be improved. At a true positive rate of 0.9, the false positive rate decreased by as much as 55%. (3) Most observers felt more confident in their decisions when using the iView, although the prototype's ergonomic problems did not allow full utilization of its capabilities. CONCLUSION: Our pilot clinical study showed that the iView has the potential to improve mammogram interpretation. In addition, the system could broaden the applicability of electronic information and provide wider access to digital technology through a relatively simple and cost-effective approach. Observers recommended several improvements in the ergonomics and default display of the system that are currently implemented by the company. A larger clinical study of the improved system is necessary to clearly demonstrate its clinical value for mammography.