Obese patients and radiography literature: what do we know about a big issue?

Venous thromboembolism in pregnant obese Individuals

Venous thrombosis and thromboembolism (VTE) remain the leading cause of direct maternal deaths, occurring within 42 days of the end of pregnancy in the UK. Pregnancy is associated with an overall 10-fold higher incidence of VTE than in the non-pregnant state and has been reported to reach up to 30-fold higher in the puerperium. This increased risk is further exacerbated by maternal obesity in a relationship that appears to be proportional with increasing Body Mass Index (BMI). Maternal obesity is the most common health problem in women of reproductive age with clinically significant health risks to women during pregnancy and after delivery. It is associated with poor perinatal and maternal outcomes, The incidence of maternal obesity has increased significantly worldwide over the last few decades and increasingly, pregnancy is being complicated by extreme or morbid obesity. In this review we discuss the challenges associated with the diagnosis and management of VTE in obese pregnant women and provide a review of the available current evidence.

The feasibility and outcomes of metabolic and bariatric surgery prior to neoplastic therapy

BACKGROUND

Metabolic and bariatric surgery (MBS) is a potent intervention for addressing obesity-related medical conditions and achieving sustainable weight loss. Beyond its conventional role, MBS has demonstrated potential to serve as a transitional step for patients requiring various interventions. However, the implications of MBS in the context of neoplasia remain understudied.

OBJECTIVES

To explore the feasibility of MBS as a possible attempt to reduce surgical and treatment risks in patients with benign tumors or low-grade cancers.

SETTING

Multicenter review from twelve tertiary referral centers spanning 8 countries.

METHODS

A retrospective review of patients with a diagnosis of primary neoplasia, deemed inoperable or high-risk due to obesity, and receiving primary MBS prior to neoplastic therapy. Data encompassed baseline characteristics, neoplasia characteristics, MBS outcomes, and neoplastic therapy outcomes.

RESULTS

Thirty-seven patients (median age 52 years, 75.7% female, median BMI of 49.1 kg/m2) were included. There were 9 distinct organs of origin of primary neoplasia, with the endometrium (43.2%) being the most common, followed by the pancreas, colon, kidney and breast. Sleeve gastrectomy (SG) was the most commonly performed MBS procedure (78.4%), with no MBS-related complications or mortalities reported over an average of 4.3 ± 3.9 years. Thirty-one patients (83.8%) eventually underwent neoplastic surgery, with a mean BMI decrease from 49.9 kg/m2 to 39.7 kg/m2 at surgery over an average of 5.8 ± 4.8 months. There were 2 (6.7%) documented mortalities associated with neoplastic surgical intervention.

CONCLUSIONS

This study highlights the potential feasibility of employing MBS prior to neoplastic therapy in patients with low-grade, less aggressive neoplasms in the context of obesity. This underscores the importance of providing a personalized, case-to-case multidisciplinary approach in the management of these patients.

Comparisons of Explicit Weight Bias Across Common Clinical Specialties of US Resident Physicians

BACKGROUND

Patients with high body weight are persistently stigmatized in medical settings, with studies demonstrating that providers endorse negative stereotypes of, and have lower regard for, higher-weight patients. Very little is known about how this weight bias varies across specialties.

OBJECTIVE

The purpose of this study is to examine how explicit weight bias varies between resident providers among sixteen of the largest residency specialties in the USA. The identification of these differences will guide the prioritization and targeting of interventions.

DESIGN

The current study utilized cross-sectional, observational data.

PARTICIPANTS

Forty-nine allopathic medical schools were recruited to participate in this national, longitudinal study. The current study utilized data from 3267 trainees in Year 2 of Residency among those who specialized in one of the most common sixteen residency programs in 2016.

MAIN MEASURES

Participants reported demographic information and residency specialties and completed three sets of measures pertaining to explicit weight bias.

KEY RESULTS

A significant minority (13-48%) of residents reported slight-to-strong agreement with each anti-fat statement. There was a significant relationship between residency specialty and anti-fat blame (F(15, 3189 = 12.87, p < .001), η2 = .06), anti-fat dislike (F(15, 3189 = 7.01, p < .001), η2 = .03), and attitudes towards obese patients (F(15, 3208 = 17.78, p < .001), η2 = .08). Primary care residents (e.g., family medicine, pediatrics) consistently reported lower levels of weight bias than those in specialty programs (e.g., orthopedic surgery, anesthesiology).

CONCLUSIONS

This study is the first to report on weight bias in a large, heterogeneous sample of US resident physicians. Problematic levels of weight bias were found in all specialties, with residents in specialty programs generally reporting more bias than those in primary care residencies. Future research should examine which factors contribute to these differences to guide intervention.

Obesity bias in diagnostic radiography students: A survey of attitudes, perceptions and technical confidence

INTRODUCTION

Obesity bias exists in healthcare professionals and students from numerous disciplines and negatively impacts the quality of care, outcomes, engagement, and satisfaction of their patients. With obesity rates continuing to rise in the United Kingdom (UK), more patients will be affected than ever, and it is becoming an increasingly important issue to tackle. This study aims to assess the attitudes to obesity of student diagnostic radiographers and determine if obesity bias exists in this population.

METHOD

Student radiographers (n = 140) at a single university in the UK were invited to complete an online survey comprising measures designed to assess levels of bias and attitudes towards obesity, including the Attitude Towards Obese Persons (ATOP) scale. Likert-type scales were used to collect quantitative data, and data analysis included descriptive statistics, frequencies, and Spearman's rank correlation coefficient.

RESULTS

Responses were received from n = 38 students. The mean ATOP score for participants was 70.37 (SD = 19.26). With 26 % (n = 10) scoring below 60, demonstrating strong negative attitudes towards obese individuals. Additionally, students (76.3 %; n = 29) indicated that they observed high levels of obesity bias whilst on clinical placement. There was a statistically significant correlation between levels of weight bias and students' confidence in working with obese patients (r(36) = 0.4, p 0.01). Students who are less confident working with obese patients had higher levels of obesity bias.

CONCLUSIONS

Obesity bias exists in radiography students at levels comparable to those that have been found previously in other healthcare professionals and students. Furthermore, radiography students lacked confidence in their technical ability to work with obese patients and lower confidence levels were associated with higher levels of obesity bias.

IMPLICATIONS FOR PRACTICE

The findings of this study provide preliminary knowledge upon which future research can be built.

Availability of CT, MRI, and endoscopy procedures for Polish individuals with morbid obesity: cross-sectional telephone survey study

Purpose

The rise in morbid obesity presents diagnostic challenges in computed tomography (CT), magnetic resonance imaging (MRI), and endoscopy. Research on the availability of these procedures for people with extreme obesity is limited. We aimed to analyse the accessibility of CT, MRI, and endoscopy procedures for people with extreme obesity in a significant sample of facilities serving in the Polish public healthcare system.

Material and methods

A telephone-based survey was conducted on healthcare facilities offering CT, MRI, or endoscopy procedures, identified using the Polish National Health Fund (NFZ) API. A refined questionnaire was utilized after a pilot study to collect details on the equipment's weight and diameter capacities, among other parameters. Of the initial 312 facilities sampled, 195 were eligible and successfully contacted, representing 9.4% of the facilities offering the procedures in the NFZ database.

Results

Of the 195 facilities, 86.4% of CT departments knew their scanner's maximum weight, 57.6% its diameter; 76.5% of MRI departments recognized their scanner's weight, and 59.2% its diameter, while 77.3% of endoscopy departments were aware of their maximum weight capacity. Approximately 28% of CT, 5% of MRI, and 39% of endoscopy departments could perform the procedure if the patient's weight was over 200 kg. Facilities knowledgeable about CT's maximum diameter and MRI's maximum weight often provided private CT/MRI services.

Conclusions

A significant proportion of Polish facilities providing CT, MRI, and endoscopic examinations in the Polish public healthcare system were unaware of their equipment's weight and diameter limits. Merely 5% of the surveyed MRI facilities could potentially accommodate a patient weighing over 200 kg.

The impact of body mass index on patient radiation dose in general radiography

The aim of the present study was to determine the influence of the body mass index (BMI) on the dose area product (DAP) and effective dose (ED) in overweight and obese patients. We also wanted to determine the typical dose values as well as suggest adjustments to clinical practice for overweight and obese patients. In this study we considered 597 patients referred for imaging of the chest in posteroanterior and lateral projection, the lumbar spine in anteroposterior (AP) and lateral projection, the pelvis, the knee in AP and lateral projection, and the shoulder in AP projection. For each examination, the image field size, tube voltage, mAs product, source-to-image receptor distance and values of DAP were collected. Based on their BMI, the patients were divided into three groups (normal weight, overweight and obese). At the end, PCXMC 2.0 software was used to calculate the ED. The study showed a statistically significant DAP and ED increase in overweight and obese patients by 28.9% up to 275.4% in the case of DAP and an increase in ED from 11.0% to 241.9% in all mentioned examinations except knee and shoulder imaging. Typical DAP values ranged from 2.2 to 54.8µGym²for normal-weight patients, from 2.2 to 87.6µGym²for overweight patients, and from 2.2 to 172.5µGym²for obese patients. Spearman's correlation coefficient revealed very weak to very strong correlations when comparing BMI and DAP, as well as when comparing BMI and ED. A strong and very strong correlation was found in the case of examinations of the torso (except for the comparison of BMI and ED in the case of lateral lumbar spine projection).

Effect of Different Anthropometric Body Indexes on Radiation Exposure in Patients Undergoing Cardiac Catheterisation and Percutaneous Coronary Intervention

Background: Patient factors, such as sex and body mass index (BMI), are known to influence patient radiation exposure. Body surface area (BSA) and its association with patient radiation exposure has not been well studied. Methods and Results: We analysed height, weight, BMI and BSA in consecutive patients undergoing cardiac catheterisation and percutaneous coronary intervention (PCI) at a high-volume Australian centre between September 2016 and April 2020 to assess their association with dose–area product (DAP, Gycm²). The mean age of the cohort was 64.5 ± 12.3 years with males comprising 68.8% (n = 8100, 5124 diagnostic cardiac catheterisation cases and 2976 PCI cases). Median male BMI was 28.4 kg/m² [IQR 25.2–32.1] versus 28.8 kg/m² [24.7–33.7] for females, p = 0.01. Males had higher BSA (2.0 ± 0.2 m²) than females (1.78 ± 0.2 m²), p = 0.001. Each 0.4 m² increase in BSA conferred a 1.32x fold change in DAP (95% CI 1.29–1.36, p ≤ 0.001). Each 5 kg/m² increase in BMI was linked to a 1.13x DAP fold change (1.12–1.14, p ≤ 0.001). Male sex conferred a 1.23x DAP fold change (1.20–1.26, p ≤ 0.001). Multivariable modelling with BMI or BSA explained 14% of DAP variance (R² 0.67 vs. 0.53 for both, p ≤ 0.001). Conclusions: BSA is an important anthropometric measure between the sexes and a key predictor of radiation dose and radiation exposure beyond sex, BMI, and weight.

Influence of Nutritional Status and Physical Exercise on Immune Response in Metabolic Syndrome

Metabolic Syndrome (MetS) is a cluster of metabolic alterations mostly related to visceral adiposity, which in turn promotes glucose intolerance and a chronic systemic inflammatory state, characterized by immune cell infiltration. Such immune system activation increases the risk of severe disease subsequent to viral infections. Strong correlations between elevated body mass index (BMI), type-2-diabetes and increased risk of hospitalization after pandemic influenza H1N1 infection have been described. Similarly, a correlation between elevated blood glucose level and SARS-CoV-2 infection severity and mortality has been described, indicating MetS as an important predictor of clinical outcomes in patients with COVID-19. Adipose secretome, including two of the most abundant and well-studied adipokines, leptin and interleukin-6, is involved in the regulation of energy metabolism and obesity-related low-grade inflammation. Similarly, skeletal muscle hormones—called myokines—released in response to physical exercise affect both metabolic homeostasis and immune system function. Of note, several circulating hormones originate from both adipose tissue and skeletal muscle and display different functions, depending on the metabolic context. This review aims to summarize recent data in the field of exercise immunology, investigating the acute and chronic effects of exercise on myokines release and immune system function.

The Bone Strain Index: An Innovative Dual X-ray Absorptiometry Bone Strength Index and Its Helpfulness in Clinical Medicine

Bone strain Index (BSI) is an innovative index of bone strength that provides information about skeletal resistance to loads not considered by existing indexes (Bone Mineral Density, BMD. Trabecular Bone Score, TBS. Hip Structural Analysis, HSA. Hip Axis Length, HAL), and, thus, improves the predictability of fragility fractures in osteoporotic patients. This improved predictability of fracture facilitates the possibility of timely intervention with appropriate therapies to reduce the risk of fracture. The development of the index was the result of combining clinical, radiographical and construction-engineering skills. In fact, from a physical point of view, primary and secondary osteoporosis, leading to bone fracture, are determined by an impairment of the physical properties of bone strength: density, internal structure, deformation and fatigue. Dual X-ray absorptiometry (DXA) is the gold standard for assessing bone properties, and it allows measurement of the BMD, which is reduced mainly in primary osteoporosis, the structural texture TBS, which can be particularly degraded in secondary osteoporosis, and the bone geometry (HSA, HAL). The authors recently conceived and developed a new bone deformation index named Bone Strain Index (BSI) that assesses the resistance of bone to loads. If the skeletal structure is equated to engineering construction, these three indexes are all considered to determine the load resistance of the construct. In particular, BSI allows clinicians to detect critical information that BMD and TBS cannot explain, and this information is essential for an accurate definition of a patient’s fracture risk. The literature demonstrates that both lumbar and femoral BSI discriminate fractured osteoporotic people, that they predict the first fragility fracture, and further fragility fractures, monitor anabolic treatment efficacy and detect patients affected by secondary osteoporosis. BSI is a new diagnostic tool that offers a unique perspective to clinical medicine to identify patients affected by primary and, specially, secondary osteoporosis. This literature review illustrates BSI’s state of the art and its ratio in clinical medicine.

Imaging patients with obesity

Obesity is a major global health issue, which directly impacts on health and is associated with multiple comorbidities. This editorial explores the challenges and clinical decision making relating to imaging patients with obesity.

Understanding radiographic decision-making when imaging obese patients: A Think-Aloud study

Introduction

The incidence of obesity has been steadily rising over the last few decades and is having a significant impact upon the health system. In radiography, a particular challenge of imaging obese patients is implementing the as low as reasonably achievable (ALARA) principle when determining radiation dose, and technical and patient‐care adaptations. This study aimed to better understand the decision‐making strategies of experienced radiographers in determining imaging and exposure factor selection in the context of imaging obese patients.

Methods

This study employed a ‘think‐aloud,’ methodology, and eight experienced diagnostic radiographers working in clinical education were recruited to perform routine AP abdominal X‐ray projections on an anthropomorphic phantom. They were asked to simultaneously verbalise emerging thoughts as they considered positioning, exposure selection and image evaluation. This process was repeated with three different phantom sizes, each representing an increased BMI from ‘healthy,’ to, ‘morbidly obese.’ Audio recordings were transcribed and interpreted via Bowman’s (1997) theory of radiographic judgement and decision‐making.

Results

Analysis of interview transcripts identified 12 key concepts considered by experienced radiographers. Differences in radiographic concepts were considered when imaging phantoms of different sizes was demonstrated. A shift from segmental (e.g. positioning) to more environmental factors (e.g. patient comfort) and an increase in the number of verbal considerations with increasing phantom size were identified. The shift in focus of decision‐making stages identified the greater need to consider contextual factors such as patient comfort and repeatability when imaging obese patients.

Conclusion

Experienced radiographers find imaging obese patients challenging and alter their perception of image quality to accommodate for patient presentation. The findings will help inform future research, practice guidelines and learning resources to provide optimal imaging and care for obese patients, especially for student education.

Imaging after laparoscopic sleeve gastrectomy - literature review with practical recommendations

In the XXI century obesity has become one of the most demanding epidemiological threats worldwide. At the same time, bariatric surgery has established itself as an effective treatment for morbidly obese patients, with laparoscopic sleeve gastrectomy (LSG) emerging as the most popular bariatric procedure. This paper reviews the role of imaging studies of patients after LSG. Computed tomography is widely considered as the method of choice in detection of complications in early postoperative period. The dynamic character of upper gastrointestinal examination allows for the assessment of passage through the gastric remnant. The paper also discusses evaluation of the shape and volume of the gastric remnant assessed by imaging studies.

Beyond Bone Mineral Density: A New Dual X-Ray Absorptiometry Index of Bone Strength to Predict Fragility Fractures, the Bone Strain Index

For a proper assessment of osteoporotic fragility fracture prediction, all aspects regarding bone mineral density, bone texture, geometry and information about strength are necessary, particularly in endocrinological and rheumatological diseases, where bone quality impairment is relevant. Data regarding bone quantity (density) and, partially, bone quality (structure and geometry) are obtained by the gold standard method of dual X-ray absorptiometry (DXA). Data about bone strength are not yet readily available. To evaluate bone resistance to strain, a new DXA-derived index based on the Finite Element Analysis (FEA) of a greyscale of density distribution measured on spine and femoral scan, namely Bone Strain Index (BSI), has recently been developed. Bone Strain Index includes local information on density distribution, bone geometry and loadings and it differs from bone mineral density (BMD) and other variables of bone quality like trabecular bone score (TBS), which are all based on the quantification of bone mass and distribution averaged over the scanned region. This state of the art review illustrates the methodology of BSI calculation, the findings of its in reproducibility and the preliminary data about its capability to predict fragility fracture and to monitor the follow up of the pharmacological treatment for osteoporosis.

Investigating perceptions of 'dose creep' amongst student radiographers: A grounded theory study

INTRODUCTION

The dose creep phenomenon is now a widely recognized concept in diagnostic radiography in light of recent technological advancements transnationally. However, this still remains underexplored amongst radiography students preparing to enter the radiography profession. In response, this study explores the perceptions of dose creep amongst undergraduate student radiographers.

METHODS

The methodological approach utilized in this research study was grounded theory. The qualitative approach aimed to uncover findings from a higher education institution in Australia. Six students were recruited and took part in semi-structured interviews. This enabled the exploration of previously uncovered data, leading to the construction of original theory within the clinical and academic environment. The data analysis employed was constant comparative analysis (CCA).

RESULTS

A number of insights emerged from the qualitative data set. For instance, the radiography students understanding of the term 'dose creep' and decision making leading to dose creep in the clinical environment is captured. This is further supported with assessment of image evaluation determining appropriate exposure factor selection and future impact upon graduation as diagnostic radiographers. The findings identify some important learning needs and actions for both clinical and academic settings which may help foster good use of X-ray exposures.

CONCLUSION

This paper concludes by affirming some challenges surrounding optimal exposure selection and the known phenomenon, dose creep. Further, this study identifies the importance of learning and teaching in the clinical environment whereby learned behaviour leads to suboptimum practices.

IMPLICATIONS FOR PRACTICE

This study advances the existing evidence base by providing a unique lens into the knowledge and understanding of dose creep amongst radiography students in both academic and clinical contexts. It is anticipated this paper will help practitioners and educators better understand potential instances of dose creep within the clinical environment.

An audit of radiographers’ practice of left-right image annotation in film-screen radiography and after installation of computed radiography in a tertiary hospital in Africa

Background

Errors in radiographic image annotation by radiographers could potentially lead to misdiagnoses by radiologists and wrong side surgery by surgeons. Such medical negligence has dire medico-legal consequences. It was hypothesized that newer technology of computed radiography (CR) and direct digital radiography (DDR) image annotation would potentially lead to a change in practice with subsequent reduction in annotation errors. Following installation of computed radiography, a modality with electronic, post-processing image annotation, the hypothesis was investigated in our study centre.

Results

A total of 72,602 and 126,482 images were documented for film-screen radiography (FSR) and computed radiography (CR), respectively in the department. From these, a sample size of 9452 made up of 4726 each for FSR and CR was drawn. Anatomical side marker errors were common in every anatomy imaged, with more errors seen in FSR (4.6%) than CR (0.6%). Collectively, an error rate of 3.0% was observed. Errors noticed were as a result of marker burnout due to over-exposure as well as marker cone off due to tight beam collimation.

Conclusion

Error rates were considerably reduced following a change from film-screen radiography (FSR) to computed radiography (CR) at the study centre. This change was, however, influenced more by a team of quality control radiographers stationed at CR workstation than by actual practice in x-ray imaging suite. Presence of anthropomorphic phantom in the teaching laboratories in the universities for demonstrations will significantly inculcate the skill needed to completely eliminate anatomical side marker (ASM) error in practice.

Radiologic assessment of abdominal aortic calcifications, atherosclerotic burden levels and statistical bias affecting the reliability

INTRODUCTION

AAC-8 and AAC-24 are two widely used scales to evaluate abdominal aortic calcification (AAC) on X-ray images. Levels of ≥3 (AAC-8) and ≥5 points (AAC-24) are of high relevance since they are associated with greater risk of cardiovascular events. Given that it is unknown, our aim was to determine the reliability of both scales at those levels of atherosclerotic burden.

METHODS

The sample (93 subjects, 67.3 ± 9.7 years, BMI 28.8 ± 3.8, 57.6% smokers, 64.1% with hypertension) was classified according to quartiles of calcification. Six clinicians evaluated AAC independently with both scales on lateral lumbar spine X-ray images. We analyzed inter-rater agreement with the intraclass correlation coefficient (ICC) and the Bland-Altman scatterplots.

RESULTS

We assessed 15 pairs of raters. Scores in both scales were significantly correlated with cardiovascular risk (r = 0.31 and r = 0.32; p < 0.005). Agreement was very high in the first quartile and moderate in the rest (p < 0.05). At cut-off points, ICC = 0.70 (95%CI, 0.54-0.86) and ICC = 0.68 (95%CI, 0.60-0.85) with AAC-8 and AAC-24. With the Bland-Altman method, mean of the differences ranged between 0 and 0.4 (AAC-8), and between 0.2 and 1 (AAC-24), while 95% limits of agreement showed values between 2.9 and 4.4 (AAC-8), and between 6 and 11.2 (AAC-24). Analyzing entire scales, ICC = 0.97 (95%CI, 0.97-0.98) and ICC = 0.98 (95%CI, 0.97-0.98) for AAC-8 and AAC-24, respectively.

CONCLUSION

Both scales presented only moderate reliability at levels of atherosclerotic burden. Analyzing quartiles with ICC and the Bland-Altman plot showed concordant results. High global ICC values traditionally reported with both scales are likely biased.

IMPLICATIONS FOR PRACTICE

AAC predicts subsequent vascular morbidity and mortality and should implicate evaluation of cardiovascular risk. Optimal visualisation of AAC and its correct assessment are mandatory in order to maximize patient care.

RADIATION DOSE DURING PELVIC RADIOGRAPHY IN RELATION TO BODY MASS INDEX

The purpose of this research was to investigate the impact of body mass index (BMI) on dose area product (DAP), effective dose (E), dose to the organs and image quality (IQ) on 200 patients referred to pelvic radiography. Patients were classified into three groups according to BMI: normal (<24.99), overweight (25.0-29.99) and obese (>30). The results showed 52% and 135% higher DAP for overweight and obese patients compared to normal-weight patients (p < 0.001). A 46 and 123% rise of E for overweight and obese patients compared to normal-weight patients (p < 0.001) was discovered. Overweight patients received 37% higher dose and obese patients 107% higher dose to the organs compared to normal-weight patients. There were no statistically significant differences between IQ, except between normal weight and overweight patients. A strong correlation (r = 0.733) was found between BMI and DAP and between BMI and E (r = 0.776).

LOW BMI PATIENT DOSE IN DIGITAL RADIOGRAPHY

In this study, the radiation dose received by 364 low body mass index (BMI) adult patients undergoing chest, abdomen, lumbar spine, kidneys and urinary bladder (KUB) and pelvis X-ray examinations in an X-ray room with a digital radiography system was evaluated. The patients' kerma area product (KAP) values were recorded, and the entrance surface air kerma (ESAK) was calculated based on the X-ray tube output, exposure parameters and technical data. The 75th percentiles of the distribution of ESAK and KAP values were also estimated. The dose values were compared with the corresponding values for normal patients obtained from a previous survey in our hospital, as well as with the national and UK diagnostic reference levels (DRLs). The correlation of dose values with patient size metrics (mass, height, BMI) was also investigated. A statistically significant difference was found in KAP and the ESAK values between low BMI and normal patients (Mann-Whitney test, p < 0.05), for all examinations studied. The percentage difference for chest PA, chest LAT, abdomen PA, lumbar spine AP, lumbar spine LAT, pelvis AP and KUB AP examinations was 40, 36, 48, 68, 57, 46 and 67% for median KAP and 26, 43, 52, 48, 19, 44 and 51% for median ESAK, respectively. The corresponding 75th percentiles for low BMI patients were 0.065, 0.349, 0.683, 1.54, 3.92, 1.11, 0.67 mGy and 0.042, 0.218, 0.450, 0.280, 0.598, 0.597, 0.267 Gycm2 in terms of ESAK and KAP values, respectively. They were 74-90% lower compared to the national diagnostic reference levels (DRLs), 35-84% and 58-82% compared to the UK DRLs, for ESAK and KAP values, respectively. Regarding the gender of the patients, no statistically significant difference was found in the dose values between female and male patients (Mann-Whitney test, p > 0.05), for all examinations studied. A statistically significant correlation was found between ESAK and KAP values with BMI for KUB AP, pelvis AP, lumbar spine AP, lumbar spine LAT and chest PA, while for chest LAT examinations, only the ESAK were significantly correlated with BMI. They also significantly correlated with the mass for KUB AP, lumbar spine LAT, abdomen PA and chest PA examinations, while no significant correlation was found between the dose values and patients' height. It can be concluded that the low BMI patients received a significantly reduced radiation dose compared to normal patients. Additional studies need to be conducted for these patient groups, which could contribute to the further development of a radiation protection culture in diagnostic radiography.

The effect of megavoltage field size on intrafraction cone-beam CT image quality

To investigate the effects of scatter from a megavoltage treatment beam on intrafraction cone beam CT (CBCT) image quality. The effects of treatment beam field size and phantom geometry were investigated as well as the clinical success of IFI. Intrafraction imaging (IFI) was performed on four phantoms with four different MV field sizes using a 6 MV FFF source. The image quality of the intrafraction CBCT images was compared to that of a baseline CBCT (i.e. with no treatment beam on) and quantified using noise and low contrast visibility. Increasing the kV tube current was explored as a possible method to reduce noise induced by the MV photon scatter in the intrafraction-CBCTs. The clinical success of all IFI patients over a 2 month period was reviewed. Intrafraction-CBCT image quality and low-contrast visibility deteriorated as MV field size increased. The extent of image degradation was found to depend on the mass of the phantom resulting in a more pronounced effect for a pelvic phantom than a thoracic phantom. While increasing the tube current could reduce the noise in the intrafraction-CBCT images, increasing the current by a factor of 4 failed to reach baseline image quality. Anatomy was found to be the primary indication of clinical IFI failure with all observed failures occurring during abdominal treatments. Image quality was found to decrease with increasing MV field size and decrease with increasing treatment anatomy mass. When considering intrafraction imaging clinically, the primary indicator of IFI failure is treatment anatomy. IFI can be used during chest treatments with high success rates but care must be taken for abdominal treatments and failures should be expected.

Complexities of spine surgery in obese patient populations: a narrative review

The obese population is particularly challenging to the spine surgeon in all phases of care. A narrative literature review was performed to review difficulties in spine surgery on the obese patient population and techniques for mitigation. We specifically aimed to assess several topics with regard to this population: patient selection and preoperative care; intraoperative and surgical techniques; and postoperative care, outcomes, and complications. The literature review demonstrated that obese patients are at increased surgical risk with spine surgery due to a variety of factors at all stages of intervention. Preoperatively, obese patients have worse outcomes with physical therapy and present technical difficulties for injections. Transport to a hospital, imaging, resuscitation, and intubation are all challenged by increased body habitus. Intraoperatively, obese patients have increased operative times, blood loss, surgical site infections, and nerve palsies. Patient positioning and intraoperative imaging may be limited. Surgery itself may be technically challenging due to body habitus and minimally invasive techniques are becoming more prevalent in this population. Postoperatively, several studies demonstrate that obese patients have inferior outcomes compared with nonobese counterparts. Patient selection is a key for elective interventions, and appropriate infrastructure aids in the ultimate outcomes for both elective and nonelective surgical treatments. Overall, obese patients present several challenges to the spine surgeon, and certain precautions can be undertaken preoperatively, intraoperatively, and postoperatively to mitigate the associated risks to optimize outcomes.

Challenges and impact of patient obesity in radiation therapy practice

INTRODUCTION

The prevalence of obesity is rapidly increasing globally and has tripled between 1975 and 2016. Obesity is reported within the literature as having a significant impact on medical practice, professionals, imaging departments and healthcare systems. It is not known how this epidemic will impact radiation therapists' working environment and practice. The aim of this study is to explore the perceived challenges and impacts of patient obesity on radiation therapy practice from the perception of radiation therapists.

METHODS

All radiation therapists working in the Republic of Ireland were invited to participate. Two focus groups were conducted with 6 and 7 participants respectively. A seven staged method of analysis, using a computerised long table approach was developed and used to analyse the data and create themes related to radiation therapists' perception of managing obese patients.

RESULTS

Perceived challenges from the radiation therapists were difficulties; (1) Setting up the patient (2) Imaging (3) communication and emotional impact.

CONCLUSION

An array of concerns were raised during this research about the increase and impact of obese patients on radiation therapists working environment. This study suggests that obese patients can present additional challenges to radiation therapists' current work practices. It is imperative that we recognise the additional challenges this patient cohort add to daily workflow. Further research is needed to identify the common key issues and how to manage this specific patient group.

IMPLICATIONS FOR PRACTICE

At the moment there are no specific management strategies/policies in place for managing obese patients; this study suggests that it is something we need to consider implementing as standard in radiation therapy departments.

Rapid kVp switching dual-energy CT in the assessment of urolithiasis in patients with large body habitus: preliminary observations on image quality and stone characterization

PURPOSE

The purpose of this study was to investigate the image quality (IQ) considerations of rapid kVp switching dual-energy CT (rsDECT) in the assessment of urolithiasis in patients with large body habitus and to evaluate whether it allows stone characterization.

MATERIALS AND METHODS

In this IRB-approved, HIPAA compliant retrospective study, 93 consecutive patients (M/F = 72/21, mean age 56.9 years, range 23-83 years) with large body habitus (> 90 kg/198 lbs) who underwent dual-energy (DE) stone protocol CT on a rapid kVp switching DECT scanner between January 2013 and December 2016 were included. Scan acquisition protocol included an initial unenhanced single-energy CT (SECT) scan of KUB followed by targeted DECT in the region of stones. Two readers evaluated both CT data sets (axial 5 mm 120 kVp/140 kVp QC/70 keV monoenergetic, material density water/iodine images and coronal/sagittal 3 mm images) for the assessment of image quality (Scores: 1-4) and characterization of stone composition (reference standard: crystallography).

RESULTS

One hundred and five CT examinations were performed in 93 patients (mean body weight 105.12 ± 13.53 kg, range 91-154 kg), and a total of 321 urinary tract calculi (mean size-4.8 ± 3.2 mm, range 1.2-22 mm) were detected. Both SECT and targeted monoenergetic images were of acceptable image quality (mean IQ: 3.77 and 3.83, kappa 0.79 and 0.87 respectively). Material density water and iodine images had lower IQ scores (mean IQ: 2.97 and 3.09 respectively) with image quality deterioration due to severe photon starvation/streak artifacts in 20% (21/105) and 17% (18/105) scans, respectively. Characterization of stone composition into uric acid/non-uric acid stones was achieved in 93.14% (299/321) of calculi (mean size: 4.99 ± 3.3 mm, range 1.2-22 mm), while 7% (22/321) stones could not be characterized (mean size 3.03 ± 1.16 mm, range 1.6-6.4 mm) (p < 0.001). Most common reason for non-characterization was image quality deterioration of the material density iodine images due to severe photon starvation artifacts. On multivariate regression, stone size and patient weight were predictors of stone composition determination on DECT (p < 0.05). The transverse diameter had a weak negative correlation with stone composition determination, but it was not statistically significant. Stone characterization into uric acid vs. non-uric acid stones was accurate in 95% (n = 38/40) of stones in comparison with crystallography.

CONCLUSION

In patients with large body habitus, rsDECT allowed characterization of most calculi (93%) despite image quality deterioration due to photon starvation/streak artifacts in up to 20% of material density images. Stone size and patient weight were predictors of stone composition determination on DECT, and small calculi in very large patients may not be characterized.

Dual-Source Dual-Energy CT in Detection and Characterization of Urinary Stones in Patients With Large Body Habitus: Observations in a Large Cohort

OBJECTIVE

The objective of our study was to investigate the impact of large body habitus on dual-energy CT (DECT) image quality and stone characterization.

MATERIALS AND METHODS

We retrospectively included 105 consecutive patients with large body habitus (> 90 kg) who underwent stone protocol DECT between 2015 and 2017. The evaluation of DECT datasets was performed for image quality assessment based on European Guidelines on Quality Criteria for Computed Tomography and for determination of stone composition (i.e., uric acid vs non-uric acid). Correlation between DECT characterization and crystallography results was performed when available. The cohort was divided into two groups on the basis of body weight (≤ 104 kg and > 104 kg), and comparisons were made for image quality and stone characterization.

RESULTS

One hundred ninety-seven urinary tract calculi (size: mean ± SD, 5.7 ± 5.3 mm; range, 1.4-56 mm) were detected in 73% (79/108) of examinations in 105 patients (weight: mean ± SD, 104.0 ± 12.7 kg; range, 91-163 kg). The overall mean image quality score of blended images and color maps was 3.7 and 3.9, respectively, and the effective dual-energy FOV limitation did not hamper stone characterization. The diagnostic acceptability scores of blended images and color maps were slightly lower in patients weighing > 104 kg than in patients ≤ 104 kg (mean scores [highest score, 4 points]: blended images, 3.62 vs 3.82 [p = 0.0314]; color maps, 3.75 vs 3.98 [p = 0.0034]), but the scores were within acceptable range. Stone characterization as uric acid versus non-uric acid was achieved in 80% (158/197) of calculi (size: mean ± SD, 6.4 ± 5.7 mm; range, 1.6-56 mm), and DECT stone characterization was (95.6%) accurate with reference to crystallography. Twenty percent (39/197) of calculi could not be characterized on DECT, and these calculi were significantly smaller in size (size: mean ± SD, 2.8 ± 1.4 mm; range, 1.4-8.2 mm; p < 0.001) than those that could be characterized. The mean size of uncharacterized calculi was slightly larger in patients weighing > 104 kg (3.3 ± 1.6 mm) than in those weighing ≤ 104 kg (2.2 ± 0.6 mm).

CONCLUSION

In patients with large body habitus, dual-source DECT provides acceptable image quality and allows characterization of almost all clinically significant calculi.

Dual-Source Dual-Energy CT Portal Venous Phase Abdominal CT Scans in Large Body Habitus Patients: Preliminary Observations on Image Quality and Material Decomposition

PURPOSE

Our objective was to evaluate image quality (IQ) and material decomposition in patients with large body habitus undergoing portal venous phase abdominal computed tomography (CT) scans on dual-source dual-energy CT (dsDECT) scanners.

METHODS

This retrospective analysis included 30 scans from consecutive patients (19 males/11 females, mean ± SD age = 55.3 ± 17.5 years, range = 27-87 years) with large body habitus (≥90 kg, mean ± SD weight = 105.4 ± 12.35, range = 91-145 kg) who underwent portal venous phase abdominal DECT examinations on dsDECT scanner between Jan 2015 and Dec 2015. Qualitative and quantitative evaluation of IQ of DECT data sets (blended, iodine, and virtual noncontrast images) was performed. The patients were categorized into 2 groups (group A, ≤104 kg; group B, >104 kg).

RESULTS

The mean ± SD patient body weight in group A was 97.2 ± 4.5 kg (range = 91-104 kg) and 114.8 ± 11.7 kg (range = 104.3-145.2 kg) for patients in group B. The diagnostic acceptability of the blended images in patients > 104 kg was lower (3.6 vs 4, <3 in 4/14 vs 0/16, P = 0.03). The extension of visceral anatomy beyond DE field of view (DEFOV) was seen in 60% (28 organs in 18 patients), the most common organs being liver and spleen. The incidence of visceral organs outside DEFOV was significantly higher in patients > 104 kg (18 vs 10, P = 0.03). Outside the DEFOV, blended images demonstrated higher image noise (mean: 14.48, range = 10.09-26.83 vs mean: 9.5, range = 7.3-15.8) P < 0.001) and lower signal-to-noise ratio (mean: 4.15, range = 1.5-7.6 vs mean: 7.5, range = 4.2-9.9) P < 0.001), and material-specific information was not available in this region. Within the DEFOV, the IQ of iodine maps and virtual non-contrast images were diagnostically acceptable with diagnostic acceptability of 3 or greater in nearly all patients. A 40-cm transverse diameter cut-off provided a good predictor of extension of visceral anatomy outside the effective DEFOV.

CONCLUSIONS

Dual-source DECT allows diagnostically acceptable IQ and material separation in patients with large body habitus with the major limitation of exclusion of patient anatomy and organs outside the effective dual-energy field of view.

Imaging of suspected pulmonary embolism and deep venous thrombosis in obese patients

Obesity is a growing problem around the world, and radiology departments frequently encounter difficulties related to large patient size. Diagnosis and management of suspected venous thromboembolism, in particular deep venous thrombosis (DVT) and pulmonary embolism (PE), are challenging even in some lean patients, and can become even more complicated in the setting of obesity. Many obstacles must be overcome to obtain imaging examinations in obese patients with suspected PE and/or DVT, and to ensure that these examinations are of sufficient quality to diagnose or exclude thromboembolic disease, or to establish an alternative diagnosis. Equipment limitations and technical issues both need to be acknowledged and addressed. Table weight limits and scanner sizes that readily accommodate obese and even morbidly obese patients are not in place at many clinical sites. There are also issues with image quality, which can be substantially compromised. We discuss current understanding of the effects of patient size on imaging in general and, more specifically, on the imaging modalities used for the diagnosis and treatment of DVT and PE. Emphasis will be placed on the technical parameters and protocol nuances, including contrast dosing, which are necessary to refine and optimize images for the diagnosis of DVT and PE in obese patients, while remaining cognizant of radiation exposure. More research is necessary to develop consistent high-level evidence regarding protocols to guide radiologists, and to help them effectively utilize emerging technology.

Just the tip of the iceberg: difficulties in assessing and managing extreme obesity in routine clinical care

As obesity prevalence increases worldwide, healthcare professionals are often faced with challenging cases associated with massive obesity. A 33-year-old woman (weight 342 kg, body mass index = 100 kg/m²) presented with respiratory failure, limb edema and ascites. Abdominal CT scan became feasible after initial weight loss and showed a large pelvic mass in contact with the left ovary. The surgical removal performed despite a high-risk profile led to the diagnosis of a giant mucinous borderline tumor whose growth was due to delayed care and responsible for multiple severe complications: sepsis, anemia, esophagitis, constipation, anorexia due to mechanical compression, undernutrition, sarcopenia and lower limb edema contributing to a severe disability. After 7 months under specialized care, her weight decreased to 180 kg, complications were treated and disability improved. This case, showing that, despite barriers, a multidisciplinary approach makes quality of care possible even in massively obese patients, is an educational example to reduce stigma.

Osteoporosis, obesity, and sarcopenia on abdominal CT: a review of epidemiology, diagnostic criteria, and management strategies for the reporting radiologist

Abdominal computed tomography (CT) is a widely performed examination, with many indications. Assessment of bone, fat, and muscle on abdominal CT can be performed in a quantitative manner. Published studies have developed diagnostic cutoffs for osteoporosis, obesity, and sarcopenia, which are summarized with pictorial examples. The epidemiological and prognostic significance of these disease states are outlined. Further diagnostic steps and treatment strategies are outlined to inform both the managing clinician and reporting radiologist. This article summarizes an unglamorous yet information-rich field, which is ripe for assessment in the dawning era of personalized medicine, and one in which the radiologist is well placed to add value to patient care.

Ultrasound Guidance to Assist Percutaneous Nephrolithotomy Reduces Radiation Exposure in Obese Patients

OBJECTIVE

To evaluate the impact of body mass index (BMI) on perioperative outcomes and radiation exposure for ultrasound (US)-guided percutaneous nephrolithotomy (PCNL).

PATIENTS AND METHODS

Data were prospectively collected for consecutive patients who underwent PCNL at the University of California, San Francisco, from July 2013 to November 2015. Patients were divided into 3 groups according to their BMI: <25 (normal weight), 25-29.9 (overweight), and >30 (obese) kg/m². Perioperative outcomes were compared between patients who underwent US-guided vs fluoroscopy-guided PCNL.

RESULTS

One hundred thirty-five patients were enrolled; 93 cases were performed under US and 42 under fluoroscopic guidance. US successfully guided renal access in 76.9% of normal weight, 79.0% of overweight, and 45.7% of obese patients (P < .05). Mean fluoroscopic screening time and radiation exposure dose were reduced for US compared to fluoroscopy cases across all BMI categories (P < .05). As BMI increased, radiation exposure dose rose disproportionately faster compared to screening time (P < .001). No significant differences among the BMI groups were found with regard to complication rate, hospital stay, and stone-free status.

CONCLUSION

US-guided PCNL may be more difficult in obese patients, but with its use, the overweight and obese experience the largest absolute reduction in radiation exposure. Because these patients are inherently at greater risk for radiation exposure compared to normal weight patients, they may benefit the most from adoption of US for PCNL.