The challenge of CT and MRI imaging of obese individuals who present to the emergency department: a national survey

The Impact of Class III Obesity on Outcomes for Vestibular Schwannoma Surgery: A Case Report

Background and Clinical Significance: Vestibular schwannomas (VS) are benign tumors arising from Schwann cells of the eighth cranial nerve. They represent approximately 8% of all intracranial tumors and have an increasing incidence. Larger VS can cause brainstem compression and hydrocephalus, and magnetic resonance imaging (MRI) is the diagnostic modality of choice. Individuals with VS and an elevated body mass index (BMI) can have more postoperative complications due to their weight, which can also negatively impact the preoperative diagnostic process and planning, as well as the surgery itself, as compromises must be made since optimal positioning of the patient is often not feasible. Increased BMI is a recognized risk factor for cerebrospinal fluid (CSF) leak after microscopic resection of a VS. Case Presentation: This report presents a case of a patient with class III obesity who had to undergo a right VS resection with preexisting hydrocephalus and the obstacles encountered by the surgical team throughout the diagnostics process since MRI could not be performed and preoperative planning had to be based on computed tomography (CT) scan; operative treatment, where suboptimal patient placement was achieved for a planned retrosigmoid approach to the pontocerebellar angle (PCA) and postoperative rehabilitation, which was hindered by his high BMI (55 kg/m2) with several complications, such as CSF leak, due to his extreme weight. Conclusions: Despite barriers, optimal tumor resection was obtained with a long neurorehabilitation process, with a favorable outcome, emphasizing the role of a multidisciplinary team.

Small bowel imaging in Crohn’s disease with a special focus on obesity, pregnancy and postsurgical assessment

Crohn’s disease (CD) is an immune-mediated, multisystem inflammatory disorder characterised by discontinuous transmural, sometimes granulomatous, inflammation of the gastrointestinal tract. Although it can occur anywhere in the gastrointestinal tract, it has a 70% predilection for the terminal ileum. Ileocolonoscopy with biopsy remains the gold standard for initial diagnosis and assessment of CD activity but has several limitations, including invasiveness, risk of complications and cost. With a shifting focus towards treatment targets including transmural healing, non-invasive imaging modalities are being used increasingly to assess the small bowel, particularly the terminal ileum. CT enterography, magnetic resonance enterography and gastrointestinal ultrasound are widely used for small bowel imaging in clinical practice and have relatively good sensitivity and specificity. Obesity is a growing problem for patients with CD and is associated with limitations in medical imaging. Equally, cross-sectional imaging in pregnant and postsurgical patients with CD has its own challenges. In this article, we review small bowel imaging in CD with a special focus on obesity, pregnancy and postsurgical assessment.

CT and MR utilization and morbidity metrics across Body Mass Index

OBJECTIVE

Obesity is a high-morbidity chronic condition and risk factor for multiple diseases that necessitate imaging. This study assesses the relationship between BMI and same-year utilization of CT and MR imaging in a large healthcare population.

METHODS

In this retrospective population-based study, all patients aged ≥18 years with a documented BMI in the multi-institutional Cosmos database were included. Cohorts were identified based on ≥1 documented BMI in 2021 within pre-defined ranges. For each cohort, we assessed the percentage of patients undergoing head, neck, chest, spine, or abdomen/pelvis CT and MR during the same year. Disease severity was quantified based on emergency department (ED) visits and mortality.

RESULTS

In our population of 49.6 million patients, same-year CT and MR utilization was 14.5 ±0.01% and 6.0±0.01%, respectively. The underweight cohort had the highest CT (25.8±0.1%) and MR (8.01 ± 0.05) imaging utilization. At high extremes of BMI (>50 kg/m2), CT utilization mildly increased (18.4±0.1%), but MR utilization decreased (5.3±0.04%). While morbidity differences may explain some BMI-utilization relationships, lower MR utilization in the BMI>50 cohort contrasts with higher age-adjusted mortality (1.8±0.03%) and ED utilization (32.4±0.1%) in this cohort relative to normal weight (1.5±0.01% and 25.7±0.02%, respectively).

CONCLUSION

Underweight patients had disproportionately high CT/MR utilization, and high extremes of BMI are associated with mildly higher CT and lower MR utilization than the normal weight cohort. The elevated mortality and ED utilization in severely obese patients contrasts with their lower MR imaging utilization. Our findings may assist public health efforts to accommodate obesity trends.

The Effects of Obesity on Health Care Delivery

The rates of obesity continue to rise among adults and children in the United States; hence, it is natural that obesity is reshaping health care delivery. This is seen in numerous ways, including physiologic, physical, social, and economic impacts. This article reviews a broad range of topics, from the effects of increased adiposity on drug pharmacokinetics and pharmacodynamics to the changes health care environments are making to accommodate patients with obesity. The significant social impacts of weight bias are reviewed, as are the economic consequences of the obesity epidemic. Finally, a patient case that demonstrates the effects of obesity on health care delivery is examined.

Technical Challenges in Endovascular Treatment of Ruptured Aneurysm in a Patient with Body Mass Index >100

BACKGROUND

Morbid obesity can pose unique challenges in the endovascular treatment of cerebrovascular diseases, particularly in the management of ruptured aneurysms.

CASE DESCRIPTION

This technical report discusses the challenges faced during the treatment of a ruptured aneurysm in a morbidly obese patient with a body mass index of 101. The technical adaptations used included the utilization of Dyna CT for routine imaging, vacuum assist devices for patient transfer, and a transradial approach to avoid groin complications. The technical adaptations used in the management of the ruptured aneurysm in the morbidly obese patient were effective in overcoming the challenges posed by the patient's obesity.

CONCLUSION

This technical report and literature review can serve as a guide for physicians treating morbidly obese patients with cerebrovascular diseases. Utilization of advanced technology and innovative approaches can aid in overcoming the challenges posed by obesity and improving patient outcomes.

Confronting racially exclusionary practices in the acquisition and analyses of neuroimaging data

Across the brain sciences, institutions and individuals have begun to actively acknowledge and address the presence of racism, bias, and associated barriers to inclusivity within our community. However, even with these recent calls to action, limited attention has been directed to inequities in the research methods and analytic approaches we use. The very process of science, including how we recruit, the methodologies we utilize and the analyses we conduct, can have marked downstream effects on the equity and generalizability of scientific discoveries across the global population. Despite our best intentions, the use of field-standard approaches can inadvertently exclude participants from engaging in research and yield biased brain-behavior relationships. To address these pressing issues, we discuss actionable ways and important questions to move the fields of neuroscience and psychology forward in designing better studies to address the history of exclusionary practices in human brain mapping.

Infrastructure Design: A Critical Element in the Care of the Patient With Obesity

ABSTRACT

The worldwide rate of obesity continues to rise, causing healthcare systems to morph to meet the demands posed by the concomitant increase in comorbidities associated with this condition. Increasing patient weight imposes its own constraints on the safety of patients and providers; therefore, a sound healthcare facility infrastructure is required to properly address the medical needs of patients with obesity. Currently, most healthcare systems-in their attitudes, equipment, and facility design-are ill equipped to meet the needs of this epidemic. In this article, we discuss the facilities and equipment design considerations in providing medical care to patients with obesity. Extending beyond the physical plant, we also touch on organizational elements that enable the healthcare provider to safely care for this challenging patient population. The rising prevalence and disease burden of excess adiposity highlight the obligation to recognize that the design needs common to all of our patients must include the particular needs of the patient with obesity.

Comparison of SAR distribution of hip and knee implantable devices in 1.5T conventional cylindrical-bore and 1.2T open-bore vertical MRI systems

PURPOSE

There is increasing use of open-bore vertical MR systems that consist of two planar RF coils. A recent study showed that the RF-induced heating of a neuromodulation device was much lower in the open-bore system at the brain and the chest imaging landmarks. This study focused on the hip and knee implants and compared the specific absorption rate (SAR) distribution in human models in a 1.2T open-bore coil with that of a 1.5T conventional birdcage coil.

METHODS

Computational modeling results were compared against the measurement values using a saline phantom. The differences in RF exposure were examined between a 1.2T open-bore coil and a 1.5T conventional birdcage coil using SAR in an anatomical human model.

RESULTS

Modeling setups were validated. The body placed closed to the coil elements led to high SAR values in the birdcage system compared with the open-bore system.

CONCLUSION

Our computational modeling showed that the 1.2T planar system demonstrated a lower intensity of SAR distribution adjacent to hip and knee implants compared with the 1.5T conventional birdcage system.

Accommodating patients with obesity and mobility difficulties: Observations from physicians

BACKGROUND

Given the growing population of U.S. adults with obesity and mobility disability, physicians will need to accommodate these patients.

OBJECTIVE

To explore attitudes and practices of US physicians related to caring for patients with obesity and mobility disability.

METHODS

Three open-ended, semi-structured, web-based focus group interviews with practicing physicians in selected specialties, which reached data saturation. Interviews were video recorded and transcribed for qualitative, conventional content analysis. Measurements included commonly expressed themes around caring for patients with obesity.

RESULTS

Physicians recognized obesity as a disability that poses challenges to high quality, safe, and efficient patient care. Observations coalesced around four themes: (1) difficulty routinely tracking weight; (2) reluctance to transfer obese patients to exam tables; (3) barriers to diagnostic testing; and (4) weight stigma. Physicians described difficulties accurately assessing weight, performing complete physical examinations, arranging diagnostic imaging, and providing prenatal care for obese patients. Lack of accessible medical diagnostic equipment impeded care for patients with obesity. Other participants did not contest comments of individual participants' that suggested weight stigma.

CONCLUSIONS

Our findings suggest that important gaps may remain in providing equitable access to care for patients with obesity, requiring additional training and accessible medical diagnostic equipment to safely accommodate these patients.

Radiation dose and image quality of high-pitch emergency abdominal CT in obese patients using third-generation dual-source CT (DSCT)

In this third-generation dual-source CT (DSCT) study, we retrospectively investigated radiation dose and image quality of portal-venous high-pitch emergency CT in 60 patients (28 female, mean age 56 years) with a body mass index (BMI) ≥ 30 kg/m2. Patients were dichotomized in groups A (median BMI 31.5 kg/m2; n = 33) and B (36.8 kg/m2; n = 27). Volumetric CT dose index (CTDIvol), size-specific dose estimate (SSDE), dose length product (DLP) and effective dose (ED) were assessed. Contrast-to-noise ratio (CNR) and dose-independent figure-of-merit (FOM) CNR were calculated. Subjective image quality was assessed using a five-point scale. Mean values of CTDIvol, SSDE as well as normalized DLP and ED were 7.6 ± 1.8 mGy, 8.0 ± 1.8 mGy, 304 ± 74 mGy * cm and 5.2 ± 1.3 mSv for group A, and 12.6 ± 3.7 mGy, 11.0 ± 2.6 mGy, 521 ± 157 mGy * cm and 8.9 ± 2.7 mSv for group B (p < 0.001). CNR of the liver and spleen as well as each calculated FOM CNR were significantly higher in group A (p < 0.001). Subjective image quality was good in both groups. In conclusion, third-generation abdominal high-pitch emergency DSCT yields good image quality in obese patients. Radiation dose increases in patients with a BMI > 36.8 kg/m2.

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.

Technical challenges of imaging & image-guided interventions in obese patients

Obese patients challenge imaging departments in their ability to obtain diagnostic quality images and to perform image-guided interventions. These technical challenges include properly accommodating large patients on imaging equipment, adjusting equipment settings to address imaging limitations, and pre-planning and preparation for image-guided interventions to insure safe and successful outcomes. Knowing and addressing these challenges can result in successfully addressing the imaging and image-guided interventions needs of obese patients.

A Survey on Coronary Atherosclerotic Plaque Tissue Characterization in Intravascular Optical Coherence Tomography

PURPOSE OF REVIEW

Atherosclerotic plaque deposition within the coronary vessel wall leads to arterial stenosis and severe catastrophic events over time. Identification of these atherosclerotic plaque components is essential to pre-estimate the risk of cardiovascular disease (CVD) and stratify them as a high or low risk. The characterization and quantification of coronary plaque components are not only vital but also a challenging task which can be possible using high-resolution imaging techniques.

RECENT FINDING

Atherosclerotic plaque components such as thin cap fibroatheroma (TCFA), fibrous cap, macrophage infiltration, large necrotic core, and thrombus are the microstructural plaque components that can be detected with only high-resolution imaging modalities such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT). Light-based OCT provides better visualization of plaque tissue layers of coronary vessel walls as compared to IVUS. Three dominant paradigms have been identified to characterize atherosclerotic plaque components based on optical attenuation coefficients, machine learning algorithms, and deep learning techniques. This review (condensation of 126 papers after downloading 150 articles) presents a detailed comparison among various methodologies utilized for plaque tissue characterization, classification, and arterial measurements in OCT. Furthermore, this review presents the different ways to predict and stratify the risk associated with the CVD based on plaque characterization and measurements in OCT. Moreover, this review discovers three different paradigms for plaque characterization and their pros and cons. Among all of the techniques, a combination of machine learning and deep learning techniques is a best possible solution that provides improved OCT-based risk stratification.

Obesity and inflammatory bowel disease: diagnostic and therapeutic implications

PURPOSE OF REVIEW

The review summarizes our current understanding of how obesity impacts diagnostic studies and therapies used in inflammatory bowel disease (IBD) as well as the safety and efficacy of medical and surgical weight loss therapies in the obese IBD patient.

RECENT FINDINGS

Many of the diagnostic tools we rely on in the identification and monitoring of IBD can be altered by obesity. Obesity is associated with increased acute phase proteins and fecal calprotectin. It can be more difficult to obtain and interpret cross sectional imaging of obese patients. Recent studies have also shown that common therapies used to treat IBD may be less effective in the obese population and may impact comorbid disease. Our understanding of how best to measure obesity is evolving. In addition to BMI, studies now include measures of visceral adiposity and subcutaneous to visceral adiposity ratios. An emerging area of interest is the safety and efficacy of obesity treatment including bariatric surgery in patients with IBD. A remaining question is how weight loss may alter the course of IBD.

SUMMARY

The proportion of obese IBD patients is on the rise. Caring for this population requires a better understanding of how obesity impacts diagnostic testing and therapeutic strategies. The approach to weight loss in this population is complex and future studies are needed to determine the safety of medical or surgical weight loss and its impact on the course of disease.

Are English CT departments and radiographers prepared for the morbidly obese patient?

INTRODUCTION

Morbid obesity is increasing in England, as is the use of CT scanning. All CT scanners have weight and body width limits. It is imperative that the radiographer performing the scan is aware of these limits, particularly in an emergency. This study aim was to determine whether radiographers are aware of their scanner limits, where they may be able to send a patient who exceeds these limits and whether a formal protocol exists. The secondary aim of the study was to determine capacities of scanners in acute trusts throughout England.

METHODS

CT radiographers from 86 English Hospital Trusts with Emergency Departments were contacted and asked questions regarding their CT scanners and their practice of CT scanning morbidly obese patients.

RESULTS

21% of CT radiographers did not know the maximum width capacity of their scanner. Only 24% knew where a nearby larger capacity scanner was located and only 3% had a formal protocol for scanning obese patients. Weight capacities ranged from 147 to 305 kg. Width capacities ranged from 55 to 100 cm. 70% had weight capacity 226 kg or less and 70% had size capacity of 78 cm or less.

CONCLUSION

Patients over 226 kg or 78 cm may not be accommodated in most (70%) trusts in England. Lack of knowledge of scanner capacities and alternative scanners for morbidly obese patients could have consequences for these patients, particularly in an emergency. The authors advise that all acute trusts have a protocol regarding CT scanning morbidly obese to prevent delays in accessing imaging.

Bariatric CT Imaging: Challenges and Solutions

The obesity epidemic in the adult and pediatric populations affects all aspects of health care, including diagnostic imaging. With the increasing prevalence of obese and morbidly obese patients, bariatric computed tomographic (CT) imaging is becoming common in day-to-day radiology practice, and a basic understanding of the unique problems that bariatric patients pose to the imaging community is crucial in any setting. Because larger patients may not fit into conventional scanners, having a CT scanner with an adequate table load limit, a large gantry aperture, a large scan field of view, and a high-power generator is a prerequisite for bariatric imaging. Iterative reconstruction methods, high tube current, and high tube voltage can reduce the image noise that is frequently seen in bariatric CT images. Truncation artifacts, cropping artifacts, and ring artifacts frequently complicate the interpretation of CT images of larger patients. If recognized, these artifacts can be easily reduced by using the proper CT equipment, scan acquisition parameters, and postprocessing options. Lastly, because of complex contrast material dynamics, contrast material-enhanced studies of bariatric patients require special attention. Understanding how the rate of injection, the scan timing, and the total mass of iodine affect vascular and parenchymal enhancement will help to optimize contrast-enhanced studies in the bariatric population. This article familiarizes the reader with the challenges that are frequently encountered at CT imaging of bariatric patients, beginning with equipment selection and ending with a review of the most commonly encountered obesity-related artifacts and the technical considerations in the acquisition of contrast-enhanced images. (©)RSNA, 2016.

Body composition and functional assessment of nutritional status in adults: a narrative review of imaging, impedance, strength and functional techniques

The accurate and valid assessment of body composition is essential for the diagnostic evaluation of nutritional status, identifying relevant outcome measures, and determining the effectiveness of current and future nutritional interventions. Developments in technology and our understanding of the influences of body composition on risk and outcome will provide practitioners with new opportunities to enhance current practice and to lead future improvements in practice. This is the second of a two-part narrative review that aims to critically evaluate body composition methodology in diverse adult populations, with a primary focus on its use in the assessment and monitoring of under-nutrition. Part one focused on anthropometric variables [Madden and Smith (2016) J Hum Nutr Diet 29: 7-25] and part two focuses on the use of imaging techniques, bioelectrical impedance analysis, markers of muscle strength and functional status, with particular reference to developments relevant to practice.

Critical care of obese patients during and after spine surgery

Obesity is one of the most prevalent health problems facing the United States today, with a recent JAMA article published in 2014 estimating the prevalence of one third of all adults in the United States being obese. Also, due to technological advancements, the incidence of spine surgeries is growing. Considering these overall increases in both obesity and the performance of spinal surgeries, it can be inferred that more spinal surgery candidates will be obese. Due to this, certain factors must be taken into consideration when dealing with spine surgeries in the obese. Obesity is closely correlated with additional medical comorbidities, including hypertension, coronary artery disease, congestive heart failure, and diabetes mellitus. The pre-operative evaluation may be more difficult, as a more extensive medical evaluation may be needed. Also, adequate radiographic images can be difficult to obtain due to patient size and equipment limitations. Administering anesthesia becomes more difficult, as does proper patient positioning. Post-operatively, the obese patient is at greater risk for reintubation, difficulty with pain control, wound infection and deep vein thrombosis. However, despite these concerns, appropriate clinical outcomes can still be achieved in the obese spine surgical candidate. Obesity, therefore, is not a contraindication to spine surgery, and appropriate patient selection remains the key to obtaining favorable clinical outcomes.

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

Obesity is a global health issue with obese patients requiring specialised diagnosis, treatment and care through the health service. The practical and social difficulties associated with medical imaging of obese patients are an increasingly common problem and it is currently unknown how student and qualified radiographers perceive and respond to these challenges. By better understanding challenges presented in providing quality imaging and care of imaging obese patients, education for both qualified and student radiographers can be enhanced. Radiographers are heavily reliant on visual and tactile senses to locate the position of anatomical structures for diagnostic imaging and determine radiation exposure through a delicate consideration of dose, image quality and anatomical attenuation. However, obese patients require modifications to routine radiographic practice in terms of movement/assisted positioning, equipment capabilities to take increased weight or coverage. These patients may also be subject to compromised radiological diagnosis through poor visualisation of structures. In this paper, the professional and educational literature was narratively reviewed to assess gaps in the evidence base related to the skill and care knowledge for obese patients. Literature was sourced relating to discrete radiographic considerations such as the technical factors of imaging obese patients, exposure and the impact of obesity on imaging departments’ service provisions. The recent literature (post-2000 to coincide with the sharp increase in global obesity) on the perceptions of health professionals and student health practitioners has also been explored because there are no specific radiographer studies to report. By understanding the research in similar fields, we may identify what common attitudes qualified and student radiographer's hold and what challenges, technical and care related, can be prepared for.

Imaging obese patients: problems and solutions

Obesity is an epidemic in the United States and Western World with an associated increasing impact on radiology departments. The increased prevalence of obesity in conjunction with the growing use and success of bariatric surgery results in an influx of obese patients into the health system in need of hospital services and care. Imaging services in particular are in demand in this patient population. Obese patients place special needs upon facilities and imaging equipment and also create technical challenges. This manuscript will address problems and potential solutions for imaging obese patients, specifically with regards to the modalities of radiography, fluoroscopy, computed tomography, and magnetic resonance imaging.

Challenges of pelvic imaging in obese women

Obesity is a major global health concern affecting all ages, socioeconomic groups, and countries. Although men have higher rates of overweight, women have higher rates of obesity. In the United States, more than 60% of women are overweight or obese, with slightly more than one-third considered frankly obese. Obesity is a major risk factor for noncommunicable diseases such as diabetes mellitus, cardiovascular disease, hypertension, stroke, and specific cancers. Obesity is associated with increased mortality for all cancers, with the highest death rates occurring in the heaviest women. Obesity can contribute to missed diagnoses, nondiagnostic results of imaging studies, imaging examination cancellation because of weight or girth restrictions, scheduling of inappropriate examinations, and increased radiation dose exposure. The utility of the clinical examination is often limited in the obese woman, which results in an even greater reliance on imaging; however, the obese woman may experience a lowered quality of and less access to medical imaging. Recognition of equipment limitations, imaging artifacts, optimization techniques, and appropriateness of modality choices is critical to providing good patient care to this health-challenged group. The clinical indication, the patient's weight, and the body diameters are three key factors to consider when choosing the most appropriate examination. Familiarity with the optimization of imaging techniques across all modalities is important to convert potentially suboptimal examinations into diagnostic-quality studies. The aim of this review is to identify key areas in which obesity affects the imaging care of women with pelvic conditions and to outline strategies to address these areas.

Obesity Overview: Causes, Epidemiology, Mortality, and Autopsy

Obesity is now recognized as a major health epidemic in the United States and around the world, both in adults and children, and has coincided with the increase in the availability of high calorie/low nutrient foods and changes in lifestyle, particularly the decrease in physical activity. Obese individuals have shorter life spans, increased risk for sudden cardiac death and a number of comorbidities such as diabetes mellitus, venous thromboembolism and respiratory dysfunction, which can negatively affect their quality of life. The increased prevalence of obesity has affected every field of medicine and the costs of treating obesity and its complications are staggering. Forensic pathology has been impacted as well, with obese and morbidly obese decedents posing major technical and practical challenges in transport, handling and autopsy procedures. This article will review the epidemiology and causes of obesity and address the impact of obesity on mortality and the everyday practice of forensic pathology.

Impact of obesity on orthopaedics

The prevalence of obesity among children and adults is increasing worldwide. There are substantial health risks and financial costs associated with the obesity epidemic that impact the practice of orthopaedic surgery. Patients with increased body mass index are more prone to sustaining distal extremity injuries than are those with a normal body mass index. Obese individuals are more likely than nonobese individuals to seek treatment for osteoarthritis of the knee.

Difficulties in diagnosing pulmonary embolism in the obese patient: a literature review

Several of the signs and symptoms of pulmonary embolism, such as dyspnea, tachypnea, and tachycardia, are common in the obese population, so these patients are frequently suspected of having a pulmonary embolism. Establishing an accurate diagnosis in this situation is often difficult. We performed a review of the literature examining the difficulty of diagnosing pulmonary embolism in obese patients. Several factors compromise the ability of clinicians to accurately diagnose pulmonary embolism in obese patients. When patients weigh over 350 lbs (159 kg), thoracic imaging often cannot be performed because of the weight limitations of the scanning equipment. If equipment is available that can scan these patients, image quality is often poor. The literature that is available to guide the clinician in this difficult clinical scenario is sparse. Access to radiology equipment that can image morbidly obese patients is improving, but questions about image quality remain. Further research on both imaging and outcomes is needed.

[Challenges for computed tomography of overweight patients]

In morbidly obese patients, computed tomography frequently represents the only viable option for non-invasive imaging diagnostics. The aim of this study was to analyze the weight limits, dose and image quality with standard CT scanners and to determine the diagnostic value and dose with a dual source XXL mode.A total of 15 patients (average body weight 189.6 ± 42 kg) were retrospectively identified who had been examined with the XXL mode. Of these patients 7 (average body weight 176.4 ± 56 kg) had been examined using both the XXL and standard protocols allowing for an intraindividual comparison in this subcollective. Additionally 14 patients weighing between 90 and 150 kg (average 106.1 ± 19 kg) examined with standard protocols were included as references. Dose, image noise and subjectively assessed image quality (rating scale 1-4) were determined. Additionally, a large abdomen phantom of 48 cm diameter was examined with both protocols at equivalent tube current-time product in order to compare the dose efficiency.The patient groups differed significantly in dose (CTDI(vol) XXL 72.9 ± 23 versus standard 16.7 ± 11 mGy; intraindividual 64.1 ± 20 versus 27.0 ± 15 mGy). The image noise was generally somewhat higher in the XXL group but significantly lower in the intraindividual comparison (liver 24.2 ± 14 HU versus 36.3 ± 20 HU; p = 0.03; fat 15.5 ± 8 HU versus 26.2 ± 12 HU; p=0.02). With ratings of 1.9 ± 0.7 and 1.8 ± 0.7 image quality did not differ significantly in general, whereas there was a clear difference in the intraindividual comparison (1.8 ± 0.8 versus 3.0 ± 1.2) and only the XXL protocol achieved diagnostic quality in all cases, while 43% of the examinations with the standard protocol were rated as non-diagnostic. The quantification of dose efficiency in the phantom scans yielded no significant difference between the protocols.Up to 150 kg body weight, CT can be performed with the standard technique at 120 kVp with tube current modulation. In larger patients diagnostic image quality can only be achieved reliably with the dual source XXL mode, although at considerably increased calculated dose. However, standard conversion factors yield false high values so that the estimation of the biologically relevant equivalent dose is very difficult.

The obese emergency patient: imaging challenges and solutions

The dramatic rise in the prevalence of obesity among children and adults in the United States over the last several decades has brought several new challenges to the delivery of healthcare. The increased utilization of and dependence on imaging for accurate and timely diagnosis has placed the radiology department in a unique position in the provision of care for the obese emergency patient. Radiology practices must be cognizant of the imaging challenges presented by the obese patient and adjust their imaging algorithms accordingly to optimize all types of diagnostic studies. The article systematically reviews common pitfalls and offers methods to improve image quality when using radiography, ultrasonography, and computed tomography to image the obese patient population.

Open treatment of pelvic and acetabular fractures

The open operative management of pelvic and acetabular fractures in the obese is technically demanding, with a significantly higher rate of complications compared with patients who are nonobese. The decision to perform surgery should involve a thorough understanding of risks, and patients should be counseled. Careful attention should be paid to patient factors; coexisting systemic conditions and patient positioning to reduce complications. Wound complications are most commonly seen, and techniques to reduce risk should be incorporated. When complications occur, aggressive management can result in successful salvage. Future areas of study should include methods to reduce risk of surgical site infections and improving our understanding of the physiologic alterations that occur with obesity. This article summarizes the current literature on open treatment of pelvic and acetabular fractures in the obese patient, reviews the physiologic adaptations of obesity as they relate to pelvic surgery, highlights risk factors for complications, and provides recommendations to reduce the incidence of complications.

Evaluation and treatment of spinal injuries in the obese patient

Given the increasing incidence and severity of obesity in the adult population, orthopaedic surgeons are evaluating and treating more acutely injured obese patients. Management of obese patients is complicated given their body habitus and associated medical comorbidities. Although evaluation and treatment are almost the same as for nonobese patients, some special considerations are necessary to prevent errors in diagnosis and treatment of obese trauma patients. This article focuses on spine injuries in obese patients. Predisposition to spinal injury, effective evaluation and early management, principles of treatment planning, operative technical pearls, and postoperative management are discussed.