Bed Position Research Articles

Auto-level System on 3D Printer Bed Using Arduino and 3D Touch Probe Sensor

The development of technology today has emerged the latest technology in three-dimensional (3D) printer machines. Problems faced by 3D printers include the position of the printer bed that is not horizontal. The position of the printer bed that is not horizontal will cause the 3D print to be skewed. To overcome the problem of tilting the bed of a 3D printer, the auto-level system is needed, which is a system that can correct the position of the base so that it becomes horizontal. In this study, an auto-leveling system was designed and made for four 3D printing base support positions. The drive for the printing press uses a stepper motor with a worm gear transmission. The controller uses an Arduino board and tested various position sensors to determine the slope of the base. The sensor tested is a 3D touch probe sensor. From the test results, the 3D touch probe sensor has a height value difference of not more than 0.05mm from each measurement position. The print base slope reference point is at the center point of the print base. The position of the other corner of the base will be adjusted in height with a stepper motor drive.

Deep learning-assisted PET imaging achieves fast scan/low-dose examination

PurposeThis study aimed to investigate the impact of a deep learning (DL)-based denoising method on the image quality and lesion detectability of 18F-FDG positron emission tomography (PET) images.MethodsFifty-two oncological patients undergoing an 18F-FDG PET/CT imaging with an acquisition of 180 s per bed position were retrospectively included. The list-mode data were rebinned into four datasets: 100% (reference), 75%, 50%, and 33.3% of the total counts, and then reconstructed by OSEM algorithm and post-processed with the DL and Gaussian filter (GS). The image quality was assessed using a 5-point Likert scale, and FDG-avid lesions were counted to measure lesion detectability. Standardized uptake values (SUVs) in livers and lesions, liver signal-to-noise ratio (SNR) and target-to-background ratio (TBR) values were compared between the methods. Subgroup analyses compared TBRs after categorizing lesions based on parameters like lesion diameter, uptake or patient habitus.ResultsThe DL method showed superior performance regarding image noise and inferior performance regarding lesion contrast in the qualitative assessment. More than 96.8% of the lesions were successfully identified in DL images. Excellent agreements on SUV in livers and lesions were found. The DL method significantly improved the liver SNR for count reduction down to 33.3% (p < 0.001). Lesion TBR was not significantly different between DL and reference images of the 75% dataset; furthermore, there was no significant difference either for lesions of > 10 mm or lesions in BMIs of > 25. For the 50% dataset, there was no significant difference between DL and reference images for TBR of lesion with > 15 mm or higher uptake than liver.ConclusionsThe developed DL method improved both liver SNR and lesion TBR indicating better image quality and lesion conspicuousness compared to GS method. Compared with the reference, it showed non-inferior image quality with reduced counts by 25–50% under various conditions.

Healthcare worker choice and low back force between self-chosen and highest bed height when boosting a patient up in bed

Healthcare workers have a high rate of low back injury due to patient handling tasks. These workers receive training in patient handling methods such as adjusting bed height, but often ignore them. In this study, 35 healthcare workers completed patient boosts at a self-chosen bed height and again with the bed in a higher standardised position. Motion capture and force data were collected for analysis. Given the choice, less than half of participants adjusted the bed at all and none of them moved the bed to the highest position (99.1 cm). The self-chosen bed position yielded significantly higher low back force than the higher position at L4-L5 and L5-S1 (p = 0.02, p = 0.01 respectively). Low back forces can be reduced by raising the bed prior to engaging in patient handling tasks, which is a simple step that can reduce forces placed on healthcare workers’ low backs. Practitioner summary: Healthcare workers experience high rates of low back pain secondary to patient handling tasks. In this cross-sectional crossover study, healthcare workers consistently chose a low bed height when boosting a patient, which resulted in higher low back loads compared to the highest bed height.

Optimal activity of [18F]FDG for Hodgkin lymphoma imaging performed on PET/CT camera with BGO crystals.

We aimed to find the minimum feasible activity of fluorodeoxyglucose ([18F]FDG) in positron emission tomography/computed tomography (PET/CT) of Hodgkin lymphoma patients performed on a camera with bismuth germanate (BGO) crystals. Ninety-one [18F]FDG PET/CT scans (each in seven Bayesian Penalized Likelihood [BPL] reconstructions with varying acquisition time per bed position - 2 min, 1.5 min, 1 min, 50 s, 40 s, 30 s, and 20 s) were independently assessed by three physicians to evaluate image quality. Mean administered activity was 3.0 ± 0.1 MBq/kg and mean uptake time was 54.0 ± 8.7 min. The series quality was subjectively marked on a 1-10 scale and then ranked 1-7 based on the mean mark. Interobserver rank correlation and intraclass correlation within each series for the three observers were calculated. Phantom studies were also performed to determine if reduced acquisition time can be directly translated into a reduced activity. Time series were marked and ranked unanimously - the longer the time of acquisition the higher the mark and rank. The interobserver agreement in the ranking was excellent (100%) with a kappa coefficient of 1.00 (95% CI [0.83-1.0]). The general intraclass correlation coefficient (agreement between the marks observers gave each time series) was very high (0.945, 95% CI [0.936-0.952]) and was higher the shorter the time per bed. According to all three observers only the series with 2 min and 1.5 min acquisition time were appropriate for assessment (mean mark ≥ 7). In phantom studies there was a linear correlation between time per bed, administered activity, and number of total prompts detected by a scanner. Hence, a reduction of acquisition time of 25% (from 2 min to 1.5 min) could be directly translated into a 25% activity reduction (from 3.0 to 2.25 MBq/kg). In patients with HL, [18F]FDG activity can be reduced by up to 25% when using a BGO crystal camera, without substantial impact on image quality.

Early mobilisation and rehabilitation in Swiss intensive care units: a cross-sectional survey.

Patients in intensive care units (ICUs) are at high risk of developing physical, functional, cognitive, and mental impairments. Early mobilisation aims to improve patient outcomes and is increasingly considered the standard of care. This survey aimed to investigate the characteristics, current use and variations of early mobilisation and rehabilitation in Swiss ICUs. We conducted a cross-sectional survey among all ICU lead physicians, who provided data on their institutional characteristics, early mobilisation and rehabilitation practices, and their perceptions of the use and variation of early rehabilitation practices in Switzerland. The survey response rate was 44% (37/84). Among ICUs caring for adults (34/37), 26 were in the German-speaking region, five in the French-speaking region, and three in the Italian-speaking region. All ICUs regularly involved physiotherapy in the rehabilitation process and 50% reported having a specialised physiotherapy team. All ICUs reported performing early mobilisation, starting within the first 7 days after ICU admission. About half reported the use of a rehabilitation (45%) or early mobilisation protocol (50%). Regular, structured, interdisciplinary rounds or meetings of the ICU care team to discuss rehabilitation measures and goals for patients were stated to be held by 53%. The respondents stated that 82% of their patients received early mobilisation measures during their ICU stay. Most frequently provided mobilisation measures included passive range of motion (97%), passive chair position in bed (97%), active range of motion muscle activation and training (88%), active side to side turning (91%), sitting on the edge of the bed (94%), transfer from bed to a chair (97%), and ambulation (94%). The proportion of ICUs providing a specific early mobilisation measure, the proportion of patients receiving it, and the time dedicated to it varied across language regions, hospital types, ICU types, and ICU sizes. Almost one third of the ICU lead physicians considered early rehabilitation to be underused in their own ICU and about half considered it to be underused in Switzerland more generally. ICU lead physicians stressed lack of personnel, financial resources, and time as key causes for underuse. Moreover, they highlighted the importance of early and systematic or protocol-based rehabilitation and interprofessional approaches that are adaptive to the patients' rehabilitation needs and potential. This survey suggests that almost all ICUs in Switzerland practice some form of early mobilisation with the aim of early rehabilitation. However, the described approaches, as well as the reported use of early mobilisation measures were heterogenous across Swiss ICUs.

68Ga-DOTA-DiPSMA PET/CT Imaging: Biodistribution, Dosimetry, and Preliminary Application in Prostate Cancer.

Purpose: This prospective trial aimed to evaluate the safety, dosimetry, and biodistribution of a novel theranostic probe 68Ga-DOTA-DiPSMA. Also, we have performed the first preliminary application with 68Ga-DOTA-DiPSMA in prostate cancer (PCa) patients. Methods: Five healthy volunteers and ten PCa patients were injected with an intravenous bolus of 68Ga-DOTA-DiPSMA. They received serial whole-body PET scans from the time of injection up to 60 min post-injection, with a second PET/CT scanning at 120 min post-injection. In PCa patients, low-dose CT scan and whole-body PET were performed with 2 min per bed position in 40 min post-injection. Absorbed organ doses and effective doses were calculated using OLINDA/EXM. Normal organ uptake and tumor lesion uptake were measured. A lesion-by-lesion analysis was performed. Results: 68Ga-DOTA-DiPSMA administration was safe and well-tolerated. The kidneys received the highest absorbed dose (114.46 ± 29.28 μSv/MBq), followed by the urinary bladder wall (100.82 ± 46.22 μSv/MBq) in accordance with the expected Prostate-Specific Membrane Antigen (PSMA) renal excretion of the tracer. The mean effective dose was 19.46 ± 1.73 μSv/MBq. The SUVmax of 68Ga-DOTA-DiPSMA PET/CT for PCa lesions, bone metastases, and lymph node metastases was 4.41 ± 2.72, 2.95 ± 1.11, and 3.26 ± 1.20, respectively. Conclusion: Injection of 68Ga-DOTA-DiPSMA is safe and associated with low absorbed and effective doses. 68Ga-DOTA-DiPSMA shows favorable kinetics and imaging characteristics in patients who warrant further head-to-head comparison to validate 68Ga-DOTA-DiPSMA as an alternative for gallium-68-labeled PSMA clinical PET. Low nonspecific uptake in normal organs of 68Ga-DOTA-DiPSMA indicates potential radioligand therapy (RLT) application when labeled with 177Lu, 90Y, or 225Ac.

Imaging Pulmonary Blood Vessels and Ventilation-Perfusion Mismatch in COVID-19.

COVID-19 hypoxemic patients although sharing a same etiology (SARS-CoV-2 infection) present themselves quite differently from one another. Patients also respond differently to prescribed medicine and to prone Vs supine bed positions. A severe pulmonary ventilation-perfusion mismatch usually triggers moderate to severe COVID-19 cases. Imaging can aid the physician in assessing severity of COVID-19. Although useful for their portability X-ray and ultrasound serving on the frontline to evaluate lung parenchymal abnormalities are unable to provide information about pulmonary vasculature and blood flow redistribution which is a consequence of hypoxemia in COVID-19. Advanced imaging modalities such as computed tomography, single-photon emission tomography, and electrical impedance tomography use a sharp algorithm visualizing pulmonary ventilation-perfusion mismatch in the abnormal and in the apparently normal parenchyma. Imaging helps to access the severity of infection, lung performance, ventilation-perfusion mismatch, and informs strategies for medical treatment. This review summarizes the capacity of these imaging modalities to assess ventilation-perfusion mismatch in COVID-19. Despite having limitations, these modalities provide vital information on blood volume distribution, pulmonary embolism, pulmonary vasculature and are useful to assess severity of lung disease and effectiveness of treatment in COVID-19 patients.

F-18 DOPA PET/CT in pediatric patients with hyperinsulinemic hypoglycemia: A correlation with genetic analysis.

Persistent hyperinsulinemic hypoglycemia is a rare but life-threatening disease of infancy and childhood. 18F-DOPA PET/CT has been shown to be a useful modality in the localization of focal pancreatic lesions in these patients. We aimed to assess the role of 18F-DOPA PET/CT in such patients at our institution. In this prospective study, 18F-DOPA PET/CT scans and clinical details of 20 children with clinical diagnosis of hyperinsulinemic hypoglycemia were reviewed. Scans were acquired at 5 min postinjection of 2-3 mCi of 18F-DOPA on dedicated PET/CT scanners (Biograph mCT, Siemens Inc and Discovery PET/CT, GE). Abdominal spot images over 1-2 bed positions were acquired. Additionally, genetic mutation status, where available, was correlated to the scan findings. Out of 20 children (7 female and 13 male), 13 were infants. The age of the children ranged from 3 months to 8 years. Fifteen children had undergone gene analysis, 12 were positive for mutation in ABCC8, 1 for GLUD-1, 1 for GCK mutations and 1 had not shown any mutation. 18F-DOPA PET/CT scan showed 5 focal pancreatic lesions in 5 children (1 in each), two focal lesions in 1 child and diffuse pancreatic uptake in 14 children. 18F-DOPA PET/CT is a useful modality for localizing focal pancreatic lesions in children with persistent hyperinsulinemic hypoglycemia. The detection rate is significantly higher in patients with ABCC8 paternal monoallelic recessive gene mutation. 18F-DOPA PET/CT scan consequent to findings on genetic analysis appears to be useful in planning the management of children with hyperinsulinism.

Interprofessional education for safe patient handling during mobilization

Background: Inter-professional education (IPE) highlights collaborative practices aimed at promoting the working relationship between two or more healthcare professions1. IPE achieves together more than what individuals can achieve to improve healthcare practices at an organizational level1. In order to reduce the risk of injury during positioning and transfers of children admitted in the Almaha units, nursing, physical therapy, and occupational therapy professionals designed and implemented a competency training program to improve safe handling and mobilization of children. The novelty in this program is that the training was conducted in the wardrooms with the children where the actual practice occurs2. This context-specific training was designed after careful assessment of the real-time environment, complex needs of our children, and the presence of cumbersome life-saving equipment connected to their bodies. The education was delivered by rehabilitation professionals on five topics for a total of 134 nurses in Almaha units. Each session lasted 60 minutes with hands-on practice with a real patient. Methods: A pre-test/post-test design was used on a convenience sample of nurses for this pilot study. An observation-based checklist was designed by the authors to measure the nursing competencies in five tasks: Chair positioning, Bed positioning, Bed-to-chair and Chair-to-bed transfers, splint application, and utilizing powered wheelchairs. A rehabilitation professional completed the checklist for all participants by observation before the education. The same checklist was completed for 30 nurses, 6 months after the training. Results: The mean percentage scores improved for all tested patient handling competencies (Table 1; Figure 1). The mean percentage in improvement was 61.2% for the task of bed positioning. No further statistical tests were performed due to the small sample size. Conclusion: Inter-professional education provided in real-life settings was found to be effective in improving the safe handling and mobilization of children with complex needs.

A time- and space-resolved catalyst deactivation study on the conversion of glycerol to aromatics using H-ZSM-5

A time- and space-resolved deactivation study on the conversion of glycerol to aromatics over H-ZSM-5 was performed. For this purpose, glycerol was vaporized/pyrolyzed in a pyrolysis section followed by a catalytic aromatization step. Benchmark performance showed an induction period of ca. 20 min, followed by a rather constant BTX yield of ca. 25.4 ± 2.2C.% for 3–4 h time on stream (TOS). Subsequently, a rapid drop in BTX yield was observed due to catalyst deactivation. Severe coking leads to coverage of catalyst surface area and blockage of micropores, particularly at the entrance of the catalyst bed at short TOS, indicating the presence of an axial coke gradient in the fixed bed reactor. At longer TOS, coke was formed throughout the bed and negligible BTX yield was shown to be associated with the presence of coke at all bed positions. Besides coking, the acidity of the catalyst was also reduced, and dealumination occurred, both with a similar time–space evolution. The results were explained by a conversion-zone migration model, which includes a deactivation zone (with severely coked catalyst), a conversion zone (BTX formation), and an induction zone (a.o. (de-)alkylation reactions), and describes the time- and space-resolved evolution of coking and relevant changes in other catalyst characteristics.

Modeling of nursing care-associated airborne transmission of SARS-CoV-2 in a real-world hospital setting

Respiratory transmission of SARS-CoV-2 from one older patient to another by airborne mechanisms in hospital and nursing home settings represents an important health challenge during the COVID-19 pandemic. However, the factors that influence the concentration of respiratory droplets and aerosols that potentially contribute to hospital- and nursing care-associated transmission of SARS-CoV-2 are not well understood. To assess the effect of health care professional (HCP) and patient activity on size and concentration of airborne particles, an optical particle counter was placed (for 24 h) in the head position of an empty bed in the hospital room of a patient admitted from the nursing home with confirmed COVID-19. The type and duration of the activity, as well as the number of HCPs providing patient care, were recorded. Concentration changes associated with specific activities were determined, and airway deposition modeling was performed using these data. Thirty-one activities were recorded, and six representative ones were selected for deposition modeling, including patient’s activities (coughing, movements, etc.), diagnostic and therapeutic interventions (e.g., diagnostic tests and drug administration), as well as nursing patient care (e.g., bedding and hygiene). The increase in particle concentration of all sizes was sensitive to the type of activity. Increases in supermicron particle concentration were associated with the number of HCPs (r = 0.66; p < 0.05) and the duration of activity (r = 0.82; p < 0.05), while submicron particles increased with all activities, mainly during the daytime. Based on simulations, the number of particles deposited in unit time was the highest in the acinar region, while deposition density rate (number/cm2/min) was the highest in the upper airways. In conclusion, even short periods of HCP-patient interaction and minimal patient activity in a hospital room or nursing home bedroom may significantly increase the concentration of submicron particles mainly depositing in the acinar regions, while mainly nursing activities increase the concentration of supermicron particles depositing in larger airways of the adjacent bed patient. Our data emphasize the need for effective interventions to limit hospital- and nursing care-associated transmission of SARS-CoV-2 and other respiratory pathogens (including viral pathogens, such as rhinoviruses, respiratory syncytial virus, influenza virus, parainfluenza virus and adenoviruses, and bacterial and fungal pathogens).

Rehabilitation of COVID 19 Patients, Bangladesh Perspective

The global outbreak of COVID 19 has created an unprecedented challenge to the society. America, Europe and India were catastrophic sufferers from this virus next to China. They had highest number of daily morbidity and mortality in the global context. Bangladesh is facing terrible experiences of dealing with this pandemic and making a tremendous turmoil in health and economic sector. Our healthcare system is overburdened with critically ill patients. Disability arising out of neurological, pulmonary, neuromuscular, and cognitive complications, need to be addressed by rehabilitation professionals. Many patients presenting with COVID-19 will have no specific airway clearance needs.There have been no reports of COVID-19 positive patients having high secretion loads that would require intensive chest physiotherapy or postural drainage. In Bangladesh in ICU settings physiatrist or physiotherapists are not directly involve in respiratory care management. In mild to moderate cases advice about a post-acute care breathing exercises, other musculoskeletal exercises, bed positioning and pressure sore care are helpful. In Bangladesh medical care facilities are not adequate in corona care hospitals especially in peripheral medical college or hospital. Many patients are dying of shortage in oxygen supplies and lack of availability of ICU. Post discharged plans of comprehensive rehabilitation are grossly neglected in discharged certificate. Our national guidelines on corona management do not have any instructions on rehabilitation management at any point. The objectives of this fast review article on corona pandemic are to highlight the global scenario and our limitations in the rehabilitation management of COVID 19 patients particularly post discharged patients and patients with long COVID complications. J Bangladesh Coll Phys Surg 2022; 40: 52-56

PET-CT scan can be a reliable alternative to bone marrow Biopsy? Comparison of PET CT scan and marrow biopsy finding in diagnosed cases of lymphoma for staging

Objectives: To determine the diagnostic accuracy of 18F-labeled fluoro-2-deoxyglucose (18FDG) positron emission tomography/ computed tomography (18FDG-PET/CT) scan for identifying bone marrow involvement in diagnosed patients with lymphoma keeping bone marrow biopsy (BMB) as gold standard. Study Design: cross-sectional study. Setting: Department of Radiology, Armed Forces Institute of Radiological Imaging (AFIRI), Rawalpindi from April 26, 2021 to October 25, 2021. Materials &amp; Methods: A total of 128 cases of lymphoma of age 20-85 years and both genders were included. Patients who had taken treatment for lymphoma or were using bone marrow-stimulant factors or drugs before undergoing PET/CT scanning were excluded. PET/CT imaging was done at AFIRI 6 HD True point PET/CT 1 hour after intravenous injection of 0.2 mCi/kg 18FDG. PET acquisition was performed for 4 minutes per bed position for seven to eight bed positions. Bone marrow was classified into three types based on signal intensity and localization by FDG uptake on PT/CT as diffuse involvement, focal involvement, and normal bone marrow. Findings from 18FDG PET/CT were compared with BMB results for determining the diagnostic accuracy of abdominal FDG PET-CT. Results: Overall sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of 18FDG-PET/CT scan for identifying bone marrow involvement in diagnosed patients with lymphoma keeping BMB as gold standard was 95.45%, 93.55%, 94.03%, 95.08%, and 94.53%, respectively. Conclusion: This study concluded that the diagnostic accuracy of 18FDG-PET/CT scan for identifying bone marrow involvement in diagnosed patients with lymphoma is very high.

Assessment of Indoor Levels of Carbon Monoxide Emission from Smoldering Mosquito Coils Used in Nigeria.

Mosquito coils are commonly burnt in indoor environments to drive away mosquitoes which are vectors for malaria parasites. The levels of carbon monoxide (CO) emitted and human health implications during smoldering of 5 different brands of mosquito coils commonly used in Nigeria were investigated in 4 microenvironments of different sizes. The experiments were done by taking a scenario of a sleeping arrangement and the farthest distance between the coil burning and an arbitrary bed position in 4 different bedrooms of different sizes in poor ventilation condition of closed doors and windows. With monitoring device, ALTAIR 5X portable gas analyzer, at the position of the bed, measurements were taking at 2 minutes interval from start to the end of burning of each coil. The emission profile was determined by making concentration-time plots of CO emission to determine its levels from the burning of each brand of the mosquito coils in each microenvironment. From the emission profile, coils A, C, and D showed that CO levels exceeded Nigeria’s Federal Ministry of Environment (FMEnv) and the World Health Organization (WHO) statutory limit of 9.0 ppm for indoor environments in each of the microenvironments between 3 and 7 hours after the burning commenced. It was concluded that the CO concentrations from smoldering mosquito coils is a function of the size of the microenvironment in which it is used. It was recommended that the size of a microenvironment be determined for consumption of a mosquito coil before it is released into the market.

Lutetium background radiation in total-body PET-A simulation study on opportunities and challenges in PET attenuation correction.

The current generation of total-body positron emission tomography (PET) scanners offer significant sensitivity increase with an extended axial imaging extent. With the large volume of lutetium-based scintillation crystals that are used as detector elements in these scanners, there is an increased flux of background radiation originating from 176Lu decay in the crystals and higher sensitivity for detecting it. Combined with the ability of scanning the entire body in a single bed position, this allows more effective utilization of the lutetium background as a transmission source for estimating 511 keV attenuation coefficients. In this study, utilization of the lutetium background radiation for attenuation correction in total-body PET was studied using Monte Carlo simulations of a 3D whole-body XCAT phantom in the uEXPLORER PET scanner, with particular focus on ultralow-dose PET scans that are now made possible with these scanners. Effects of an increased acceptance angle, reduced scan durations, and Compton scattering on PET quantification were studied. Furthermore, quantification accuracy of lutetium-based attenuation correction was compared for a 20-min scan of the whole body on the uEXPLORER, a one-meter-long, and a conventional 24-cm-long scanner. Quantification and lesion contrast were minimally affected in both long axial field-of-view scanners and in a whole-body 20-min scan, the mean bias in all analyzed organs of interest were within a ±10% range compared to ground-truth activity maps. Quantification was affected in certain organs, when scan duration was reduced to 5 min or a reduced acceptance angle of 17° was used. Analysis of the Compton scattered events suggests that implementing a scatter correction method for the transmission data will be required, and increasing the energy threshold from 250 keV to 290 keV can reduce the computational costs and data rates, with negligible effects on PET quantification. Finally, the current results can serve as groundwork for transferring lutetium-based attenuation correction into research and clinical practice.

The effect of modern PET technology and techniques on the EANM paediatric dosage card

AimRecent advancements in PET technology have brought with it significant improvements in PET performance and image quality. In particular, the extension of the axial field of view of PET systems, and the introduction of semiconductor technology into the PET detector, initially for PET/MR, and more recently available long-field-of-view PET/CT systems (≥ 25 cm) have brought a step change improvement in the sensitivity of PET scanners. Given the requirement to limit paediatric doses, this increase in sensitivity is extremely welcome for the imaging of children and young people. This is even more relevant with PET/MR, where the lack of CT exposures brings further dose reduction benefits to this population. In this short article, we give some details around the benefits around new PET technology including PET/MR and its implications on the EANM paediatric dosage card.Material and methods Reflecting on EANM adult guidance on injected activities, and making reference to bed overlap and the concept of MBq.min bed−1 kg−1, we use published data on image quality from PET/MR systems to update the paediatric dosage card for PET/MR and extended axial field of view (≥ 25 cm) PET/CT systems. However, this communication does not cover the expansion of paediatric dosing for the half-body and total-body scanners that have recently come to market.ResultsIn analogy to the existing EANM dosage card, new parameters for the EANM paediatric dosage card were developed (class B, baseline value: 10.7 MBq, minimum recommended activity 10 MBq). The recommended administered activities for the systems considered in this communication range from 11 MBq [18F]FDG for a child with a weight of 3 kg to 149 MBq [18F]FDG for a paediatric patient weight of 68 kg, assuming a scan of 3 min per bed position. The mean effective dose over all ages (1 year and older) is 2.85 mSv.ConclusionWith this, recommendations for paediatric dosing are given for systems that have not been considered previously.

Effect of Trendelenburg position during prone ventilation in fifteen COVID-19 patients. Observational study

Background Prone position ventilation has shown to improve oxygenation and mortality in severe ARDS. The data of prone position ventilation during severe ARDS secondary to COVID-19 have shown similar benefit in oxygenation and mortality. Usually, patient placed in prone position are placed flat or in reverse Trendelenburg positioning to decrease risk of aspiration and abdominal girth compressing the chest. To date, no studies are available to compare the effects of positioning the bed in different angles during the prone position ventilation. Methods An observational study in fifteen patients with severe ARDS secondary to COVID-19 who were placed in the prone position for the first time. All the patients were sedated and chemically paralyzed with no spontaneous effort. All patients were ventilated with the pressure-controlled mode with set PEEP according to the pressure-volume curves. Five patients had esophageal balloon manometry to estimate pleural pressures and trans-pulmonary pressures. Patients were initially placed in reverse Trendelenburg position and later in Trendelenburg position. Tidal volume and respiratory compliance were observed for 30 minutes after bed positioning has been achieved. Tidal volume and total respiratory compliance in both Trendelenburg and reverse Trendelenburg position were compared. Ventilator settings were not changed during the observation. No patients were suspected of increased intra-cranial or intra-ocular pressures. T-test was done to compare the values. Results Tidal volume significantly increased by 80.26 ± 23.4 ml/breath (95% CI 37.7 - 122.9) from 391.3 ± 52.7 to 471.6 ± 60.9 (20.5%) P 0.001. The respiratory system compliance significantly increased by 4.9 ml/cmH2O (95% CI 1.4 - 8.4) from 34.6 ± 4.7 to 39.5 ± 4.6 (14%) P 0.001. Of the five patients with esophageal balloon, the lung compliance significantly increased by 16.7 ml/cmH2O (95% CI 12.8 – 20.6) from 66.6 ± 1.7 to 83.3 ± 3.3 (25%) P 0.001. The chest wall compliance had small but non-significant increase by 1.5 ml/cmH2O (95% CI -1.3 – 4.3) from 65 ± 1.4 to 66.5 ± 2.3 (2%) P 0.085. Conclusion In this study, statistically significant increase in tidal volume, lung and respiratory system compliance were observed in patients placed in the Trendelenburg position during prone position ventilation. The results reflect the effect of body positioning during prone position ventilation. These effects may be the reflection of altered ventilation distribution throughout the lungs and change in pleural pressure as well as trans-pulmonary pressure during body positioning. More studies need to be done to confirm and examine this phenomenon. Precautions should be taken as this maneuver can increase the intra-cranial and intra-ocular pressures. Keywords: COVID-19, Trendelenburg, Reverse Trendelenburg, ARDS

Reduced Acquisition Time per Bed Position for PET/MRI Using 68Ga-RM2 or 68Ga-PSMA-11 in Patients With Prostate Cancer: A Retrospective Analysis.

BACKGROUND. Growing clinical adoption of PET/MRI for prostate cancer (PC) evaluation has increased interest in reducing PET/MRI scanning times. Reducing acquisition time per bed position below current times of at least 5 minutes would allow shorter examination lengths. OBJECTIVE. The purpose of this study was to evaluate the effect of different reduced PET acquisition times in patients with PC who underwent 68Ga-PSMA-11 or 68Ga-RM2 PET/MRI using highly sensitive silicon photomultiplier-based PET detectors. METHODS. This study involved retrospective review of men with PC who underwent PET/MRI as part of one of two prospective trials. Fifty men (mean [± SD] age, 69.9 ± 6.8 years) who underwent 68Ga-RM2 PET/MRI and 50 men (mean age, 66.6 ± 5.7 years) who underwent 68Ga-PSMA-11 PET/MRI were included. PET/MRI used a time-of-flight-enabled system with silicon photomultiplier-based detectors. The acquisition time was 4 minutes per bed position. PET data were reconstructed using acquisition times of 30 seconds, 1 minute, 2 minutes, 3 minutes, and 4 minutes. Three readers independently assessed image quality for each reconstruction using a 5-point Likert scale (with 1 denoting nondiagnostic and 5 indicating excellent quality). One reader measured SUVmax for up to six lesions per patient. Two readers independently assessed lesion conspicuity using a a 3-point Likert scale (with 1 indicating that lesions were not visualized and 3 denoting that they were definitely visualized). RESULTS. Mean image quality across readers at 30 seconds, 1 minutes, 2 minutes, 3 minutes, and 4 minutes was, for 68Ga-RM2 PET/MRI, from 1.0 ± 0.2 to 1.7 ± 0.7, 2.0 ± 0.3 to 2.6 ± 0.8, 3.1 ± 0.5 to 3.9 ± 0.8, 4.6 ± 0.6 to 4.7 ± 0.6, and 4.8 ± 0.4 to 4.8 ± 0.5, respectively, and for 68Ga-PSMA-11 PET/MRI it was from 1.2 ± 0.4 to 1.8 ± 0.6, 2.2 ± 0.4 to 2.8 ± 0.7, 3.6 ± 0.6 to 4.1± 0.8, 4.8 ± 0.4 to 4.9 ± 0.4, and 4.9 ± 0.3 to 5.0 ± 0.2, respectively. The mean lesion SUVmax for 68Ga-RM2 PET/MRI was 11.1 ± 12.4, 10.2 ± 11.7, 9.6 ± 11.3, 9.5 ± 11.6, and 9.4 ± 11.6, respectively, and for 68Ga-PSMA-11 PET/MRI it was 14.7 ± 8.2, 12.9 ± 7.4, 12.1 ± 7.8, 11.7 ± 7.9, and 11.6 ± 7.9, respectively. Mean lesion conspicuity (reader 1/reader 2) was, for 68Ga-RM2 PET/MRI, 2.4 ± 0.5/2.7 ± 0.5, 2.9 ± 0.3/2.9 ± 0.3, 3.0 ± 0.0/3.0 ± 0.0, 3.0 ± 0.0/3.0 ± 0.0, and 3.0 ± 0.0/3.0 ± 0.0, respectively, and for 68Ga-PSMA-11 PET/MRI it was 2.6 ± 0.5/2.8 ± 0.4, 3.0 ± 0.2/2.9 ± 0.3, 3.0 ± 0.1/3.0 ± 0.2, 3.0 ± 0.0/3.0 ± 0.0, and 3.0 ± 0.0/3.0 ± 0.0, respectively. CONCLUSION. Our data support routine 3-minute acquisitions, which provided results very similar to those for 4-minute acquisitions. Two-minute acquisitions, although they lowered quality somewhat, provided acceptable performance and warrant consideration. CLINICAL IMPACT. When PC is evaluated using modern PET/MRI equipment, time per bed position may be reduced compared with historically used times. TRIAL REGISTRATION. ClinicalTrials.gov NCT02624518 and NCT02678351.

Jejunal diverticular disease complicated with spontaneous perforation: A rare case of acute abdomen and literature review

Introduction: The jejunal diverticular disease is an uncommon clinical pathology. In general, these diverticula are an incidentaloma found on imaging exams that can be seen in elective surgeries for other purposes. In a minority of cases it causes symptoms which result from serious complications such as perforation. Case report: A 56-year-old male patient, previously healthy and without comorbidities, was admitted to the emergency department due to abdominal pain which had started 24 hours ago, without improvement. On examination, the patient was in pain and in Mohammedan prayer's position in bed and had a distended abdomen with signs of peritoneal irritation. An abdominal tomography showed massive distension of intestinal loops and free fluid in the peritoneal cavity. He underwent exploratory laparotomy which showed multiple diverticula in the jejunum and one of them was perforated. Segmental enterectomy with primary anastomosis was performed. Conclusion: Complicated jejunal diverticular disease should be ranked among the differential diagnoses in acute perforating abdomen. Segmental jejunal resection is the treatment of choice. Keywords: small bowel diverticulum; jejuno-ileal diverticula; diverticulitis; perforation; acute abdomen; surgery.

Radioembolization Dosimetry with Total-Body 90Y PET.

Transarterial radioembolization (TARE) is a locoregional radiopharmaceutical therapy based on the delivery of radioactive 90Y microspheres to liver tumors. The importance of personalized dosimetry to make TARE safer and more effective has been demonstrated in recent clinical studies, stressing the need for quantification of the dose-response relationship to ultimately optimize the administered activity before treatment and image it after treatment. 90Y dosimetric studies are challenging because of the lack of accurate and precise methods but are best realized with PET combined with Monte Carlo simulations and other image modalities to calculate a segmental dose distribution. The aim of this study was to assess the suitability of imaging 90Y PET patients with the total-body PET/CT uEXPLORER and to investigate possible improvements in TARE 90Y PET-based dosimetry. The uEXPLORER is the first commercially available ultra-high-resolution (171 cps/kBq) total-body digital PET/CT device with a 194-cm axial PET field of view that enables the whole body to be scanned at a single bed position. Methods: Two PET/CT scanners were evaluated in this study: the Biograph mCT and the total-body uEXPLORER. Images of a National Electrical Manufacturers Association (NEMA) image-quality phantom and 2 patients were reconstructed using our standard clinical oncology protocol. A late portal phase contrast-enhanced CT scan was used to contour the liver segments and create corresponding volumes of interest. To calculate the absorbed dose, Monte Carlo simulations were performed using Geant4 Application for Tomographic Emission (GATE). The absorbed dose and dose-volume histograms were calculated for all 6 spheres (diameters ranging from 10 to 37 mm) of the NEMA phantom, the liver segments, and the entire liver. Differences between the phantom doses and an analytic ground truth were quantified through the root mean squared error. Results: The uEXPLORER showed a higher signal-to-noise ratio at 10- and 13-mm diameters, consistent with its high spatial resolution and system sensitivity. The total liver-absorbed dose showed excellent agreement between the uEXPLORER and the mCT for both patients, with differences lower than 0.2%. Larger differences of up to 60% were observed when comparing the liver segment doses. All dose-volume histograms were in good agreement, with narrower tails for the uEXPLORER in all segments, indicating lower image noise. Conclusion: This patient study is compelling for the use of total-body 90Y PET for liver dosimetry. The uEXPLORER scanner showed a better signal-to-noise ratio than mCT, especially in lower-count regions of interest, which is expected to improve dose quantification and tumor dosimetry.