Search

Paget-Schroetter syndrome (PSS) is an uncommon disorder which causes thrombosis of the subclavian vein (SV). This is due to compression of the SV by the surrounding anatomical structures. The optimal management of PSS remains subject to debate, with endovascular intervention and open surgical decompression being favoured current options. This review article evaluates both approaches to the management of PSS, while also presenting a case series with long-term follow-up of patients that underwent open surgical intervention for PSS.The clinical outcomes of PSS patients undergoing different 4 surgical approaches to perform surgical decompression are included. A literature review, across publications from PubMed, Embase, and Web of Science, was conducted with specific criteria to facilitate evaluation of both open surgical and endovascular approaches to the management of PSS.Evaluation of data from the included case series and available literature suggests that endovascular thrombolytic devices offer better clinical results, however, SV decompression is still required for successful resolution.An approach to PSS encompassing endovascular intervention followed by surgical anatomical decompression may provide optimal outcomes as both intrinsic lesions and extrinsic compression of the SV is treated. However, further prospective investigation into this field is warranted.

Chest X-ray (CXR) use in pre-MRI safety screening, such as for lead-less implanted electronic device (LLIED) recognition, is common. To assist CXR interpretation, we "pre-deployed" an artificial intelligence (AI) model to assess (1) accuracies in LLIED-type (and consequently safety-level) identification, (2) safety implications of LLIED nondetections or misidentifications, (3) infrastructural or workflow requirements, and (4) demands related to model adaptation to real-world conditions.A two-tier cascading methodology for LLIED detection/localization and identification on a frontal CXR was applied to evaluate the performance of the original nine-class AI model. With the unexpected early appearance of LLIED types during simulated real-world trialing, retraining of a newer 12-class version preceded retrialing. A zero footprint (ZF) graphical user interface (GUI)/viewer with DICOM-based output was developed for inference-result display and adjudication, supporting end-user engagement and model continuous learning and/or modernization.During model testing or trialing using both the nine-class and 12-class models, robust detection/localization was consistently 100%, with mAP 0.99 from fivefold cross-validation. Safety-level categorization was high during both testing (Our LLIED-related AI methodology supports (1) 100% detection sensitivity, (2) high identification (including MRI-safety) accuracy, and (3) future model deployment with facilitated inference-result display and adjudication for ongoing model adaptation to future real-world experiences.

This research examines the making of American drug policy and the Harrison Narcotics Act of 1914. Depending upon the analytical model employed, different explanations can be offered for early drug policy development. From a rational perspective, the goal of the Harrison Act was to improve relations with China; from an organizational perspective, the Act was intended to protect the financial interests of doctors and pharmacists; and from a political process perspective, the Act was the result of a Progressive-era crusade of a few policy entrepreneurs.

Acute type B aortic dissection (TBAD) is relatively uncommon with an estimated incidence of up to 8 cases per 100,000 individuals annually. It can be classified based on presenting clinical and radiological features into complicated and uncomplicated. Following the initial tear, the direction and extent of the dissection flap is unpredictable, possibly propagating proximally or distally. One consequence of a dissection flap is the occurrence of organ malperfusion by occlusion of the origin of the branch vessel. The 2 types of malperfusion in TBAD are static and dynamic, with the latter being the more common mechanism. Thoracic endovascular aortic repair (TEVAR) has demonstrated its high safety and efficacy when used for TBAD and subsequent malperfusion.This original study specifically examines patients diagnosed with acute TBAD and treated with TEVAR at a single vascular unit, focusing on those presenting with organ malperfusion.Over 16 years, 28 TBAD patients were admitted to a single center and treated using TEVAR. After clinical examination, all patients underwent computed tomography of the thorax and abdomen/pelvis to confirm the diagnosis and classify the extent of the dissection proximally and distally. Once diagnosed, patients were transferred to the high dependency unit and started on blood pressure medication. Subsequent computed tomography scans were performed to classify patients, after which TEVAR was performed.Twenty five patients underwent TEVAR for TBAD, of which 8 (32%) had symptoms of organ malperfusion. The majority of cases presented with hypertension (89%), describing a sudden onset of upper/midthoracic pain. The origin of the left subclavian artery was occluded in 14 (56%) patients with 9 (64%) needing an extra-anatomical bypass. There was only a single mortality due to a posterior circulation stroke 2 days after TEVAR. Median (range) length of coverage of thoracic aorta by the stent-graft was 33 (15-35) cm. The true lumen (TL) perfused the celiac artery in 6/8 malperfusion patients, superior mesenteric artery in 7/8, right renal artery in 6/8, and, conversely, left renal artery in only 2/8.Complicated TBADs behave in an unpredictable manner as it seems the propagating intimal flap invariably maintains vital organ perfusion via the TL. Maintenance of abdominal vessels perfusion from the TL following TEVAR is vital to ensuring optimal results.

Background and aim of study The origin of the vertebral artery (VA) from the left subclavian (LSA) is variable and must be considered when proximal ligation or embolization is performed post thoracic endovascular aortic repair (TEVAR) and extra-anatomical bypass (EAB). A retrospective study was conducted to understand the patency of the LSA and VAs after TEVAR and the relationship of the EAB to the LSA. Methods Fifty-six patients underwent TEVAR where the LSA origin was occluded. A comparison was performed between the length of the proximal LSA from the arch of the aorta to the origin of the VA. Patient outcomes included posterior or anterior circulation cerebrovascular accident, spinal cord ischemia (SCI), and symptoms and signs of left arm ischemia (LAI). Thirty one underwent EAB with 8 undergoing occlusion of the LSA proximal to the origin of the left VA. A further 25 underwent TEVAR with no EAB performed. The mean (standard deviation) of origin of the VA from the origin at the arch was 37.0 (12.9) mm compared to 34.0 (13.7) mm in those where no bypass was performed (p 0.45). Four patients underwent intraluminal plug occlusion and four had external ligation of the proximal LSA in those undergoing EAB. Conclusions Careful evaluation of the LSA is needed when planning TEVAR as occlusion techniques may be dependent on a minimum length of the VA from the aortic arch. The mean length of the VA from the aorta has high heterogeneity which may dictate the optimum occlusion method for LSA.

Background Majority of research and commercial efforts have focussed on use of artificial intelligence (AI) for fracture detection in adults, despite the greater long-term clinical and medicolegal implications of missed fractures in children. The objective of this study was to assess the available literature regarding diagnostic performance of AI tools for paediatric fracture assessment on imaging, and where available, how this compares with the performance of human readers. Materials and methods MEDLINE, Embase and Cochrane Library databases were queried for studies published between 1 January 2011 and 2021 using terms related to ‘fracture’, ‘artificial intelligence’, ‘imaging’ and ‘children’. Risk of bias was assessed using a modified QUADAS-2 tool. Descriptive statistics for diagnostic accuracies were collated. Results Nine eligible articles from 362 publications were included, with most (8/9) evaluating fracture detection on radiographs, with the elbow being the most common body part. Nearly all articles used data derived from a single institution, and used deep learning methodology with only a few (2/9) performing external validation. Accuracy rates generated by AI ranged from 88.8 to 97.9%. In two of the three articles where AI performance was compared to human readers, sensitivity rates for AI were marginally higher, but this was not statistically significant. Conclusions Wide heterogeneity in the literature with limited information on algorithm performance on external datasets makes it difficult to understand how such tools may generalise to a wider paediatric population. Further research using a multicentric dataset with real-world evaluation would help to better understand the impact of these tools.

SUMMARY: In the first part of this 2-part series, we described how to implement microscopy coil MR imaging of the orbits. Beyond being a useful anatomic educational tool, microscopy coil MR imaging has valuable applications in clinical practice. By depicting deep tissue tumor extension, which cannot be evaluated clinically, ophthalmic surgeons can minimize the surgical field, preserve normal anatomy when possible, and maximize the accuracy of resection margins. Here we demonstrate common and uncommon pathologies that may be encountered in orbital microscopy coil MR imaging practice and discuss the imaging appearance, the underlying pathologic processes, and the clinical relevance of the microscopy coil MR imaging findings.

Purpose Dual‐energy computed tomography (DECT) has been proposed for quantification of hepatic iron concentration (IC). However, the lower limit of quantification (LLOQ) has not been established, limiting the clinical adoption of this technology. In this study, we aim to (a) establish the LLOQ using phantoms and (b) investigate the effects of patient size, dose level, energy combination, and reconstruction method. Methods Three phantom sizes and eight vials of ferric nitrate solution with IC ranging from 0 to 10 mg/ml were used. DECT scans were performed at 80/140 and 100/140Sn kVp, and using five different levels of CT dose index (CTDI). An image‐domain three‐material‐decomposition algorithm was used to calculate the IC. The LLOQ was determined based on the coefficient of variation from repeated measurements. Results The measured IC correlated strongly with the true IC in the small and medium phantoms (R2 of linear regression > 0.99) and moderately in the large phantom (0.8

Objectives Takayasu's arteritis is a large vessel vasculitis which usually involves the aorta and its first generation branches. Aortic dissection, however, is a rare manifestation of Takayasu's arteritis and for this reason optimum management in both short and long term is unknown. Methods This is a case of a 31-year-old female presenting with acute type B AD in association with underlying TA which failed to respond to conservative management and underwent thoracic stent grafting (TEVAR). Results Despite successful coverage of the intimal breach in the thoracic aorta by TEVAR there were complications with delivery of the stent which required a conduit sutured to the right common iliac artery. Also post-TEVAR computed tomography showed a localised dissection of the origin of the left common carotid artery which may have been iatrogenic possibly due to the stiff guidewire used during delivery of the stent graft to the thoracic aorta. Conclusions The use of TEVAR for an acute type B AD in those with TA may be problematic. The fragility of the major arteries increases the likelihood of iatrogenic periprocedural complications and long-term surveillance is essential due to significant chance of further arterial complications in type B AD occurring in TA.

In mild cognitive impairment (MCI), identifying individuals at high risk for progressive cognitive deterioration can be useful for prognostication and intervention. This study quantitatively characterizes cognitive decline rates in MCI and tests whether volumetric data from baseline magnetic resonance imaging (MRI) can predict accelerated cognitive decline.The authors retrospectively examined Alzheimer Disease Neuroimaging Initiative data to obtain serial Mini-Mental Status Exam (MMSE) scores, diagnoses, and the following baseline MRI volumes: total intracranial volume, whole-brain and ventricular volumes, and volumes of the hippocampus, entorhinal cortex, fusiform gyrus, and medial temporal lobe. Subjects with24 months or4 measurements of MMSE data were excluded. Predictive modeling of fast cognitive decline (defined as0.6/year) from baseline volumetric data was performed on subjects with MCI using a single hidden layer neural network.Among 698 baseline MCI subjects, the median annual decline in the MMSE score was 1.3 for converters to dementia versus 0.11 for stable MCI (P0.001). A 0.6/year threshold captured dementia conversion with 82% accuracy (sensitivity 79%, specificity 85%, area under the receiver operating characteristic curve 0.88). Regional volumes on baseline MRI predicted fast cognitive decline with a test accuracy of 71%.An MMSE score decrease of0.6/year is associated with MCI-to-dementia conversion and can be predicted from baseline MRI.

Wound complications following arterial surgery in the groin are relatively common and can result in significant morbidity and mortality. Vascularised muscle flaps (VMF) may be used as an adjunct to aid healing, either to manage complications or prophylactically. This series describes 46 patients who received sartorius or gracilis muscle flaps, of which 70% were performed as a salvage procedure to treat complications ranging from wound breakdown to vascular graft infection. The remaining 30% were performed at the time of the arterial surgery in patients with risk factors such as re‐do surgery or immunosuppression. The peri‐operative mortality rate was 9% and the major amputation rate was 26%, reflecting the complexity of patients that require intervention. Overall, 85% achieved successful healing in the groin without the need for further treatment following VMF. Only one case of flap necrosis occurred. Wound healing complications occurred more commonly after sartorius muscle flaps. The gracilis muscle offers a bulkier mass and greater mobility and so may be preferable, particularly for larger groin defects. This series has shown that VMF offer a safe and reliable option for selected cases to achieve wound healing in the groin in patients with often significant co‐morbidities.

Microscopy coil MR imaging of the orbits has been described previously as a technique for anatomic depiction. In the first part of this 2-part series, the improvement in spatial resolution that the technique offers compared with conventional MR imaging of the orbits is demonstrated. We provide a guide to implementing the technique, sharing pearls and pitfalls gleaned from our own practice to make implementation of microscopy coil MR imaging at your own center easy. As a quick reference guide to the small-scale structures encountered when reading the studies, a short anatomy section is included, which doubles as a showcase for the high-quality imaging that can be obtained. In the second part, our experience of microscopy coil MR imaging in day-to-day clinical practice takes it far beyond being a useful anatomic educational tool. Through a series of interesting cases, we highlight the added benefit of microscopy coil MR imaging compared with standard orbital MR imaging.

Pancreatic pathologies are varied and wide-ranging, and a multidisciplinary approach is essential for effective diagnosis and management. We describe image-guided percutaneous (nonendoscopic) interventions in the management of pancreatic disease, with emphasis on inflammatory and neoplastic pancreatic pathologies and on the transplanted pancreas. Image-guided treatments for the complications of pancreatitis include percutaneous interventions on simple and complex peripancreatic collections, pseudocysts, and fistulas. Vascular interventions predominantly focus on the treatment of pseudoaneurysms, hemorrhagic pseudocysts, and arteriovenous malformations. Emerging ablative techniques for pancreatic cancer are promising and include percutaneous radiofrequency ablation, microwave ablation, irreversible electroporation, and electrochemotherapy. Image-guided interventions on the transplanted pancreas commonly include percutaneous biopsy and drainage in addition to endovascular treatments of vascular complications.

There is a wide range of available biological databases developed by bioinformatics experts, employing different methods to extract biological data. In this paper, we investigate and evaluate the performance of some of these methods in terms of their ability to efficiently access bioinformatics databases using web-based interfaces. These methods retrieve bioinformatics information using structured and semi-structured data tools, which are able to retrieve data from remote database servers. This study distinguishes each of these approaches and contrasts these tools. We used Sequence Retrieval System (SRS) and Entrez search tools for structured data, while Perl and BioPerl search programs were used for semi-structured data to retrieve complex queries including a combination of text and numeric information. The study concludes that the use of semi-structured data tools for accessing bioinformatics databases is a viable alternative to the structured tools, though each method is shown to have certain inherent advantages and disadvantages., 16 pages

The renal arteries (RAs) are important vessels that usually arise from the abdominal aorta and supply the kidneys; thus, these arteries play a vital role in physiologic functions such as hemofiltration and blood pressure regulation. An understanding of the basis for embryologic development and the frequently variable anatomy of the RAs is necessary to fully appreciate the range of diseases and the implications for procedural planning. Hemorrhage from an RA is relatively common and is typically traumatic or spontaneous, with the latter form often seen in association with underlying tumors or arteriopathy. Accurate diagnostic evaluation of RA disease due to conditions such as atherosclerosis, fibromuscular dysplasia, vasculitis, aneurysm, arteriovenous shunt, embolic disease, and dissection is dependent on the use of multimodality imaging and is essential for selecting appropriate clinical management, with endovascular therapy having a key role in treatment. Surgical considerations include extra-anatomic renal bypass, which remains an important treatment option even in this era of endovascular therapy, and RA embolization as an adjunct to tumor surgery. A novel area of research interest is the potential role of RA denervation in the management of refractory hypertension. ©RSNA, 2021.

Introduction Thoracic endovascular aortic repair (TEVAR) has become an accepted treatment for thoracic aortic disease. However, the principal complications relate to coverage of the thoracic aortic wall and deliberate occlusion of aortic branches over a potentially long segment. Complications include risk of stroke, spinal cord ischaemia (SCI) and arterial insufficiency to the left arm (left arm ischaemia (LAI)). This study specifically scrutinised the development of SCI and LAI after TEVAR for interventions for thoracic aortic disease from 1999 to 2020. In particular, those who underwent extra-anatomical bypass (both immediate and late) were compared to the length of thoracic aortic coverage by the stent graft. Materials and methods Ninety-eight patients underwent TEVAR. The presenting symptoms, pathology, procedural and follow-up data were collected prospectively with particular evidence of stroke, SCI and LAI both immediate onset and after 48 h of graft placement. Results Fifty underwent TEVAR for an aneurysm (thoracoabdominal aortic aneurysm), 22 for dissection, 19 for acute transection and 7 for intramural haematoma/pseudoaneurysm of the thoracic aorta. Twenty-nine (30%) required a debranching procedure to increase the proximal landing zone (1 aorto-carotid subclavian bypass, 10 carotid/carotid subclavian bypass and 18 carotid/subclavian bypass). Ten patients (10%) died within 30 days of TEVAR. Twenty-four grafts covered the left subclavian artery origin without a carotid/subclavian bypass. Five required a delayed carotid/subclavian bypass for LAI (4) and SCI (1). Six developed immediate signs of SCI after TEVAR and these 11 (group i) had a mean (SD) length of coverage of the thoracic aorta of 30.2 (10.6) cm compared to 21.5 (11.2) cm (group g) in those who had no LAI or SCI post TEVAR, p Conclusions In this series, delayed carotid/subclavian bypass may be required for chronic arm ischaemia and less so for SCI. The length of coverage of thoracic aorta during TEVAR is a factor in the development of delayed SCI and LAI occurrence. Carotid subclavian bypass is required for certain patients undergoing TEVAR (particularly if greater than 20 cm of thoracic aorta is covered).

Coronary computed tomography angiography (CCTA) evaluation of chest pain patients in an emergency department (ED) is considered appropriate. While a “negative” CCTA interpretation supports direct patient discharge from an ED, labor-intensive analyses are required, with accuracy in jeopardy from distractions. We describe the development of an artificial intelligence (AI) algorithm and workflow for assisting qualified interpreting physicians in CCTA screening for total absence of coronary atherosclerosis. The two-phase approach consisted of (1) phase 1—development and preliminary testing of an algorithm for vessel-centerline extraction classification in a balanced study population (n = 500 with 50% disease prevalence) derived by retrospective random case selection, and (2) phase 2—simulated clinical Trialing of developed algorithm on a per-case (entire coronary artery tree) basis in a more “real-world” study population (n = 100 with 28% disease prevalence) from an ED chest pain series. This allowed pre-deployment evaluation of the AI-based CCTA screening application which provides vessel-by-vessel graphic display of algorithm inference results integrated into a clinically capable viewer. Algorithm performance evaluation used area under the receiver operating characteristic curve (AUC-ROC); confusion matrices reflected ground truth vs AI determinations. The vessel-based algorithm demonstrated strong performance with AUC-ROC = 0.96. In both phase 1 and phase 2, independent of disease prevalence differences, negative predictive values at the case level were very high at 95%. The rate of completion of the algorithm workflow process (96% with inference results in 55–80 s) in phase 2 depended on adequate image quality. There is potential for this AI application to assist in CCTA interpretation to help extricate atherosclerosis from chest pain presentations.

Aortic compliance and distensibility reflect overall wall stiffness, an extremely important and fundamental parameter altered in multiple diseases including hypertension, coronary artery disease, aortic aneurysm, and so on. Magnetic resonance elastography (MRE) is an innovative noninvasive imaging technique used to estimate the stiffness of soft tissues, including those comprising the wall of the aorta. This chapter describes (1) the principle of aortic MRE; (2) the motivation for use of aortic MRE for vascular applications; and (3) the current state-of-the-art in the development of aortic MRE, including the required hardware and MR pulse sequences. Finally, applications of aortic MRE and future potential application in characterizing coronary artery stiffness are also discussed.

Introduction Magnetic resonance elastography (MRE)-derived aortic stiffness is a potential biomarker for multiple cardiovascular diseases. Currently, gradient-recalled echo (GRE) MRE is a widely accepted technique to estimate aortic stiffness. However, multi-slice GRE MRE requires multiple breath-holds (BHs), which can be challenging for patients who cannot consistently hold their breath. The aim of this study was to investigate the feasibility of a multi-slice spin-echo echo-planar imaging (SE-EPI) MRE sequence for quantifying in vivo aortic stiffness using a free-breathing (FB) protocol and a single-BH protocol. Method On Scanner 1, 25 healthy subjects participated in the validation of FB SE-EPI against FB GRE. On Scanner 2, another 15 healthy subjects were recruited to compare FB SE-EPI with single-BH SE-EPI. Among all volunteers, five participants were studied on both scanners to investigate the inter-scanner reproducibility of FB SE-EPI aortic MRE. Bland-Altman analysis, Lin's concordance correlation coefficient (LCCC) and coefficient of variation (COV) were evaluated. The phase-difference signal-to-noise ratios (PD SNR) were compared. Results Aortic MRE using FB SE-EPI and FB GRE yielded similar stiffnesses (paired t-test, P = 0.19), with LCCC = 0.97. The FB SE-EPI measurements were reproducible (intra-scanner LCCC = 0.96) and highly repeatable (LCCC = 0.99). The FB SE-EPI MRE was also reproducible across different scanners (inter-scanner LCCC = 0.96). Single-BH SE-EPI scans yielded similar stiffness to FB SE-EPI scans (LCCC = 0.99) and demonstrated a low COV of 2.67% across five repeated measurements. Conclusion Multi-slice SE-EPI aortic MRE using an FB protocol or a single-BH protocol is reproducible and repeatable with advantage over multi-slice FB GRE in reducing acquisition time. Additionally, FB SE-EPI MRE provides a potential alternative to BH scans for patients who have challenges in holding their breath.

Purpose: Sharing medical images between institutions, or even inside the same institution, is restricted by various laws and regulations; research projects requiring large datasets may suffer as a result. These limitations might be addressed by an abundant supply of synthetic data that (1) are representative (i.e., the synthetic data could produce comparable research results as the original data) and (2) do not closely resemble the original images (i.e., patient privacy is protected). We introduce a framework that generates data with these requirements leveraging generative adversarial network (GAN) ensembles in a controlled fashion. Approach: To this end, an adaptive ensemble scaling strategy with the objective of representativeness is defined. A sampled Frechet distance-based constraint was then created to eliminate poorly converged candidates. Finally, a mutual information-based validation metric was embedded into the framework to confirm there are visual differences between the original and the generated synthetic images. Results: The applicability of the solution is demonstrated with a case study for generating three-dimensional brain metastasis (BM) from T1-weighted contrast-enhanced MRI studies. A previously published BM detection system was reported to produce 9.12 false-positives at 90% detection sensitivity based on the original data. By using the synthetic data generated with the proposed framework, the system produced 9.53 false-positives at the same sensitivity level. Conclusions: Achieving comparable algorithm performance relying solely on synthetic data unveils a significant potential to eliminate/reduce patient privacy concerns when sharing data in medical imaging.

Acute Proximal Femoral Fractures are a growing health concern among the aging population. These fractures are often associated with significant morbidity and mortality as well as reduced quality of life. Furthermore, with the increasing life expectancy owing to advances in healthcare, the number of proximal femoral fractures may increase by a factor of 2 to 3, since the majority of fractures occur in patients over the age of 65. In this paper, we show that by using transfer learning and leveraging pre-trained models, we can achieve very high accuracy in detecting fractures and that they can be localized utilizing class activation maps.

OBJECTIVES Using maximum diameter of an abdominal aortic aneurysm (AAA) alone for management can lead to delayed interventions or unnecessary urgent repairs. Abdominal aortic aneurysm stiffness plays an important role in its expansion and rupture. In vivo aortic magnetic resonance elastography (MRE) was developed to spatially measure AAA stiffness in previous pilot studies and has not been thoroughly validated and evaluated for its potential clinical value. This study aims to evaluate noninvasive in vivo aortic MRE-derived stiffness in an AAA porcine model and investigate the relationships between MRE-derived AAA stiffness and (1) histopathology, (2) uniaxial tensile test, and (3) burst testing for assessing MRE's potential in evaluating AAA rupture risk. MATERIALS AND METHODS Abdominal aortic aneurysm was induced in 31 Yorkshire pigs (n = 226 stiffness measurements). Animals were randomly divided into 3 cohorts: 2-week, 4-week, and 4-week-burst. Aortic MRE was sequentially performed. Histopathologic analyses were performed to quantify elastin, collagen, and mineral densities. Uniaxial tensile test and burst testing were conducted to measure peak stress and burst pressure for assessing the ultimate wall strength. RESULTS Magnetic resonance elastography-derived AAA stiffness was significantly higher than the normal aorta. Significant reduction in elastin and collagen densities as well as increased mineralization was observed in AAAs. Uniaxial tensile test and burst testing revealed reduced ultimate wall strength. Magnetic resonance elastography-derived aortic stiffness correlated to elastin density (ρ = -0.68; P < 0.0001; n = 60) and mineralization (ρ = 0.59; P < 0.0001; n = 60). Inverse correlations were observed between aortic stiffness and peak stress (ρ = -0.32; P = 0.0495; n = 38) as well as burst pressure (ρ = -0.55; P = 0.0116; n = 20). CONCLUSIONS Noninvasive in vivo aortic MRE successfully detected aortic wall stiffening, confirming the extracellular matrix remodeling observed in the histopathologic analyses. These mural changes diminished wall strength. Inverse correlation between MRE-derived aortic stiffness and aortic wall strength suggests that MRE-derived stiffness can be a potential biomarker for clinically assessing AAA wall status and rupture potential.

Purpose: Our study investigates whether a machine-learning-based system can predict the rate of cognitive decline in mildly cognitively impaired patients by processing only the clinical and imaging data collected at the initial visit. Approach: We built a predictive model based on a supervised hybrid neural network utilizing a three-dimensional convolutional neural network to perform volume analysis of magnetic resonance imaging (MRI) and integration of nonimaging clinical data at the fully connected layer of the architecture. The experiments are conducted on the Alzheimer's Disease Neuroimaging Initiative dataset. Results: Experimental results confirm that there is a correlation between cognitive decline and the data obtained at the first visit. The system achieved an area under the receiver operator curve of 0.70 for cognitive decline class prediction. Conclusion: To our knowledge, this is the first study that predicts "slowly deteriorating/stable" or "rapidly deteriorating" classes by processing routinely collected baseline clinical and demographic data [baseline MRI, baseline mini-mental state examination (MMSE), scalar volumetric data, age, gender, education, ethnicity, and race]. The training data are built based on MMSE-rate values. Unlike the studies in the literature that focus on predicting mild cognitive impairment (MCI)-to-Alzheimer's disease conversion and disease classification, we approach the problem as an early prediction of cognitive decline rate in MCI patients.

BACKGROUND Open surgery for abdominal aortic aneurysms in the UK is usually performed via a midline transperitoneal incision. However, the left retroperitoneal (RP) approach may be beneficial for juxtarenal abdominal aortic aneurysms and certain physiological reasons. One potential disadvantage is that the left kidney usually requires mobilization anteromedially risking injury to the renal tract and possibly the ureter. METHODS In this retrospective study, the time of onset, clinical presentation and treatment of left renal tract complications are scrutinized and discussed. Reasons for open aortic surgery as opposed to endovascular repair being undertaken were documented. Also, the aortic cross-clamp positions and type of reconstruction were examined. RESULTS A total of 208 patients underwent RP aortic surgery for aneurysmal disease. The aortic cross-clamp positions were infrarenal in 115 (55%), suprarenal in 78 (38%) and supra-superior mesenteric artery or supracoeliac in 15 (7%). Two percent (4/208) sustained ureteric complications and all occurred in the upper third of the left ureter. The time of onset of symptoms ranged from 2 to 14 days post-operatively with a median of 3.5. Clinical signs were non-specific including pyrexia, tachycardia and flank pain. CONCLUSION Ureteric complications following left RP aortic surgery is uncommon and usually occurs in the upper third of the renal tract. Trauma appears to be the most common cause, although ureteric ischaemia can occur but presents later particularly in those with comorbidities.

Building robust deep learning-based models requires large quantities of diverse training data. In this study, we investigate the use of federated learning (FL) to build medical imaging classification models in a real-world collaborative setting. Seven clinical institutions from across the world joined this FL effort to train a model for breast density classification based on Breast Imaging, Reporting & Data System (BI-RADS). We show that despite substantial differences among the datasets from all sites (mammography system, class distribution, and data set size) and without centralizing data, we can successfully train AI models in federation. The results show that models trained using FL perform 6.3% on average better than their counterparts trained on an institute’s local data alone. Furthermore, we show a 45.8% relative improvement in the models’ generalizability when evaluated on the other participating sites’ testing data.

Chronic chest pain (CCP) of a cardiac etiology is a common clinical problem. The diagnosis and classification of the case of chest pain has rapidly evolved providing the clinician with multiple cardiac imaging strategies. Though scintigraphy and rest echocardiography remain as appropriate imaging tools in the diagnostic evaluation, new technology is available. Current evidence supports the use of alternative imaging tests such as coronary computed tomography angiography (CCTA), cardiac MRI (CMRI), or Rb-82 PET/CT. Since multiple imaging modalities are available to the clinician, the most appropriate noninvasive imaging strategy will be based upon the patient's clinical presentation and clinical status. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

While there is no single diagnostic test for heart failure (HF), imaging plays a supportive role beginning with confirmation of HF, especially by detecting ventricular dysfunction ( Variant 1 ). Ejection fraction (EF) is important in HF classification, and imaging plays a subsequent role in differentiation between HF with reduced EF (HFrEF) versus preserved EF (HFpEF) ( Variant 2 ). Once HFrEF is identified, distinction between ischemic and nonischemic etiologies with imaging support ( Variant 3 ) facilitates further planning. Imaging approaches which are usually appropriate include: both resting transthoracic echocardiography (TTE) and chest radiography for Variant 1 ; resting TTE and/or MRI (including functional, without absolute need for contrast) for Variant 2 ; and for Variant 3 , a. Coronary CTA or coronary arteriography (if high pretest probability/symptoms for ischemic disease) for coronary assessment; b. Rest/vasodilator stress SPECT/CT, PET/CT, or MRI for myocardial perfusion assessment; c. Rest/exercise or inotropic stress TTE for myocardial contraction assessment; or d. MRI (including morphologic with contrast) for myocardial characterization. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The mechanical properties of soft tissues are closely associated with a variety of diseases. This motivates the development of elastography techniques in which tissue mechanical properties are quantitatively estimated through imaging. Magnetic resonance elastography (MRE) is a noninvasive phase-contrast MR technique wherein shear modulus of soft tissue can be spatially and temporally estimated. MRE has recently received significant attention due to its capability in noninvasively estimating tissue mechanical properties, which can offer considerable diagnostic potential. In this work, recent technology advances of MRE, its future clinical applications, and the related limitations will be discussed.

Purpose To quantify the burden and distribution of asymptomatic atherosclerosis in a population with a low to intermediate risk of cardiovascular disease. Materials and Methods Between June 2008 and February 2013, 1528 participants with 10-year risk of cardiovascular disease less than 20% were prospectively enrolled. They underwent whole-body magnetic resonance (MR) angiography at 3.0 T by using a two-injection, four-station acquisition technique. Thirty-one arterial segments were scored according to maximum stenosis. Scores were summed and normalized for the number of assessable arterial segments to provide a standardized atheroma score (SAS). Multiple linear regression was performed to assess effects of risk factors on atheroma burden. Results A total of 1513 participants (577 [37.9%] men; median age, 53.5 years; range, 40-83 years) completed the study protocol. Among 46 903 potentially analyzable segments, 46 601 (99.4%) were interpretable. Among these, 2468 segments (5%) demonstrated stenoses, of which 1649 (3.5%) showed stenosis less than 50% and 484 (1.0%) showed stenosis greater than or equal to 50%. Vascular stenoses were distributed throughout the body with no localized distribution. Seven hundred forty-seven (49.4%) participants had at least one stenotic vessel, and 408 (27.0%) participants had multiple stenotic vessels. At multivariable linear regression, SAS correlated with age (B = 3.4; 95% confidence interval: 2.61, 4.20), heart rate (B = 1.23; 95% confidence interval: 0.51, 1.95), systolic blood pressure (B = 0.02; 95% confidence interval: 0.01, 0.03), smoking status (B = 0.79; 95% confidence interval: 0.44, 1.15), and socioeconomic status (B = -0.06; 95% confidence interval: -0.10, -0.02) (P < .01 for all). Conclusion Whole-body MR angiography identifies early vascular disease at a population level. Although disease prevalence is low on a per-vessel level, vascular disease is common on a per-participant level, even in this low- to intermediate-risk cohort. © RSNA, 2018 Online supplemental material is available for this article.

The present study was funded by the Souter Charitable Foundation and the Chest, Heart and Stroke Scotland Charity. The statistician was funded by TENOVUS, Tayside. JRWM is supported by the Wellcome Trust through the Scottish Translational Medicine and Therapeutics Initiative (Grant no. WT 085664) in the form of a Clinical Research Fellowship. Background: Arteriosclerosis (arterial stiffening) is associated with future cardiovascular events, with this effect postulated to be due to its effect on cardiac afterload, atherosclerosis (plaque formation) progression or both, but with limited evidence examining these early in disease formation. The aim of the current study is to examine the association between arteriosclerosis, atherosclerosis and ventricular remodelling in a population at low-intermediate cardiovascular risk. Methods: One thousand six hundred fifty-one subjects free of clinical cardiovascular disease and with a

This article discusses imaging guidelines for five dyspnea variants: (1) dyspnea due to heart failure, ischemia not excluded; (2) dyspnea due to suspected nonischemic heart failure, ischemia excluded; (3) dyspnea due to suspected valvular heart disease, ischemia excluded; (4) dyspnea due to suspected cardiac arrhythmia, ischemia excluded; and (5) dyspnea due to suspected pericardial disease, ischemia excluded. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Purpose Aortic stiffness plays an important role in evaluating and predicting the progression of systemic arterial hypertension (SAH). The aim of this study is to determine the stiffness of aortic wall using MR elastography (MRE) in a hypertensive porcine model and compare it against invasive aortic pressure measurements. Methods Renal wrapping surgery was performed on eight pigs to induce SAH. Aortic MRE was performed at baseline and 2 months postsurgery using a retrospectively pulse-gated gradient-echo MRE sequence on a 1.5 tesla scanner. Mechanical waves of 70 Hz were introduced into the aorta. Invasive central aortic pressure measurements were obtained prior to each scan to calculate mean arterial pressure (MAP). MRE data were analyzed to obtain effective aortic stiffness. Spearman's rank correlation analysis was performed to assess the relationship between MAP and MRE-derived aortic stiffness. Results Significant increase in effective aortic stiffness was observed between baseline and 2 months postsurgery measurements (paired t test; P = 0.004). The average MAP, determined by pooling all animals, was 65.24 ± 9.42 mm Hg at baseline and 92.57 ± 11.80 mm Hg 2 months postsurgery with P

PURPOSE: To delineate image data curation needs and describe a locally designed graphical user interface (GUI) to aid radiologists in image annotation for artificial intelligence (AI) applications in medical imaging. MATERIALS AND METHODS: GUI components support image analysis toolboxes, picture archiving and communication system integration, third-party applications, processing of scripting languages, and integration of deep learning libraries. For clinical AI applications, GUI components included two-dimensional segmentation and classification; three-dimensional segmentation and quantification; and three-dimensional segmentation, quantification, and classification. To assess radiologist engagement and performance efficiency associated with GUI-related capabilities, image annotation rate (studies per day) and speed (minutes per case) were evaluated in two clinical scenarios of varying complexity: hip fracture detection and coronary atherosclerotic plaque demarcation and stenosis grading. RESULTS: For hip fracture, 1050 radiographs were annotated over 7 days (150 studies per day; median speed: 10 seconds per study [interquartile range, 3–21 seconds per study]). A total of 294 coronary CT angiographic studies with 1843 arteries and branches were annotated for atherosclerotic plaque over 23 days (15.2 studies [80.1 vessels] per day; median speed: 6.08 minutes per study [interquartile range, 2.8–10.6 minutes per study] and 73 seconds per vessel [interquartile range, 20.9–155 seconds per vessel]). CONCLUSION: GUI-component compatibility with common image analysis tools facilitates radiologist engagement in image data curation, including image annotation, supporting AI application development and evolution for medical imaging. When complemented by other GUI elements, a continuous integrated workflow supporting formation of an agile deep neural network life cycle results. Supplemental material is available for this article. © RSNA, 2019

Rationale and Objectives The purpose of this study was to investigate the potential effects of patient size and radiation dose on the accuracy of iodine quantification using dual-source dual-energy computed tomography (CT). Materials and Methods Three phantoms representing different patient sizes were constructed, containing iodine inserts with concentrations from 0 to 20 mg/ml. Dual-energy CT scans were performed at six dose levels from 2 to 30 mGy. Iodine concentrations were measured using a three-material-decomposition algorithm and their accuracy was assessed. Results In a small phantom, iodine quantification was accurate and consistent at all dose levels. In a medium phantom, minor underestimations were observed, and the results were consistent except at low dose. In the large phantom, more significant underestimation of iodine concentration was observed at higher doses (≥15 mGy), which was attributed to the beam-hardening effect. At lower doses, increasing upward bias was observed in the CT number, leading to significant overestimations of both iodine concentration and fat fraction, which was attributed to the photon-starvation effect. The severity of the latter effect was determined by mA instead of mAs, suggesting that the electronic noise, rather than the quantum noise, was responsible for the bias. Using higher kVp for the low-energy tube was found to alleviate these effects. Conclusion Reliable iodine quantification can be achieved using dual-source CT, but the result can be affected by patient size and dose rate. In large patients, biases may occur due to the beam-hardening and the photon-starvation effects, in which case higher dose rate and higher kVp are recommended to minimize these effects.

AIM To investigate the feasibility of applying a deep convolutional neural network (CNN) for detection/localisation of acute proximal femoral fractures (APFFs) on hip radiographs. MATERIALS AND METHODS This study had institutional review board approval. Radiographs of 307 patients with APFFs and 310 normal patients were identified. A split ratio of 3/1/1 was used to create training, validation, and test datasets. To test the validity of the proposed model, a 20-fold cross-validation was performed. The anonymised images from the test cohort were shown to two groups of radiologists: musculoskeletal radiologists and diagnostic radiology residents. Each reader was asked to assess if there was a fracture and localise it if one was detected. The area under the receiver operator characteristics curve (AUC), sensitivity, and specificity were calculated for the CNN and readers. RESULTS The mean AUC was 0.9944 with a standard deviation of 0.0036. Mean sensitivity and specificity for fracture detection was 97.1% (81.5/84) and 96.7% (118/122), respectively. There was good concordance with saliency maps for lesion identification, but sensitivity was lower for characterising location (subcapital/transcervical, 84.1%; basicervical/intertrochanteric, 77%; subtrochanteric, 20%). Musculoskeletal radiologists showed a sensitivity and specificity for fracture detection of 100% and 100% respectively, while residents showed 100% and 96.8%, respectively. For fracture localisation, the performance decreased slightly for human readers. CONCLUSION The proposed CNN algorithm showed high accuracy for detection of APFFs, but the performance was lower for fracture localisation. Overall performance of the CNN was lower than that of radiologists, especially in localizing fracture location.

Brain Metastases (BM) complicate 20–40% of cancer cases. BM lesions can present as punctate (1 mm) foci, requiring high-precision Magnetic Resonance Imaging (MRI) in order to prevent inadequate or delayed BM treatment. However, BM lesion detection remains challenging partly due to their structural similarities to normal structures (e.g., vasculature). We propose a BM-detection framework using a single-sequence gadolinium-enhanced T1-weighted 3D MRI dataset. The framework focuses on the detection of smaller (

The American College of Cardiology's Executive Committee and Cardiovascular Imaging Section Leadership Council convened a discussion regarding the future of cardiac imaging among thought leaders in the field during a 2 day Think Tank. Participants were charged with thinking broadly about the future of imaging and developing a roadmap to address critical challenges. Key areas of discussion included: 1) how can cardiac imaging services thrive in our new world of value-based health care? 2) Who is the cardiac imager of the future and what is the role of the multimodality imager? 3) How can we nurture innovation and research in imaging? And 4) how can we maximize imaging information and optimize outcomes? This document describes the proceedings of this Think Tank.

Purpose Aortic wall shear stress (WSSFlow) alters endothelial function, which in-turn changes aortic wall stiffness leading to remodeling in different disease states. Therefore, the aims of this study are to determine normal physiologic correlations between: (1) Magnetic Resonance Elastography (MRE)-derived aortic wall stiffness (WSMRE) and WSSFlow; (2) WSMRE and mean velocity; (3) WSMRE and pulse wave velocity (PWV);( 4) WSMRE and mean peak flow; and (5) WSMRE, WSSFlow and age using MRE and 4D-flow MRI in the abdominal aorta in healthy human subjects. Materials and Methods Cardiac-gated aortic MRE and 4D-flow MRI data were acquired in 24 healthy volunteers using a 3 Tesla scanner. For MRE, 70 Hz external motion was applied to obtain wave images in all spatial directions in a separate breathhold. Whereas, 4D-flow data was acquired under free-breathing. Wave images in all the directions were processed to obtain three-dimensional-weighted stiffness map at end-systole (ES). WSSFlow, mean velocity, PWV and mean peak flow were obtained using 4D-flow data. Pearson correlation was performed to determine association between all variables. Results A significant negative correlation was observed between: (1) ES WSMRE and WSSFlow in both axial (r = -0.62; P = 0.006) and circumferential (r = -0.52; P = 0.016) directions; (2) ES WSMRE and mean velocity (r = -0.58; P = 0.012); and (3) age and WSSFlow in both axial (r = -0.71; P

Purpose To determine alteration in left ventricular (LV) myocardial stiffness (MS) with hypertension (HTN). Cardiac MR elastography (MRE) was used to estimate MS in HTN induced pigs and MRE-derived MS measurements were compared against LV pressure, thickness and circumferential strain. Materials and Methods Renal-wrapping surgery was performed to induce HTN in eight pigs. LV catheterization (to measure pressure) and cardiac MRI (1.5 Tesla; gradient echo-MRE and tagging) was performed pre-surgery at baseline (Bx), and post-surgery at month 1 (M1) and month 2 (M2). Images were analyzed to estimate LV-MS, thickness, and circumferential strain across the cardiac cycle. The associations between end-diastolic (ED) and end-systolic (ES) MS and (i) mean LV pressure; (ii) ED and ES thickness, respectively; and (iii) circumferential strain were evaluated using Spearman's correlation method. Results From Bx to M2, mean pressure, MRE-derived stiffness, and thickness increased while circumferential strain decreased significantly (slope test, P ≤ 0.05). Both ED and ES MS had significant positive correlation with (i) mean pressure (ED MS: ρ = 0.56; P = 0.005 and ES MS: ρ = 0.45; P = 0.03); (ii) ED thickness ( ρ = 0.73; P

Purpose To estimate change in left ventricular (LV) end-systolic and end-diastolic myocardial stiffness (MS) in pigs induced with myocardial infarction (MI) with disease progression using cardiac magnetic resonance elastography (MRE) and to compare it against ex vivo mechanical testing, LV circumferential strain, and magnetic resonance imaging (MRI) relaxometry parameters (T1, T2, and extracellular volume fraction [ECV]). Materials and Methods MRI (1.5T) was performed on seven pigs, before surgery (Bx), and 10 (D10), and 21 (D21) days after creating MI. Cardiac MRE-derived MS was measured in infarcted region (MIR) and remote region (RR), and validated against mechanical testing-derived MS obtained postsacrifice on D21. Circumferential strain and MRI relaxometry parameters (T2, T1, and ECV) were also obtained. Multiparametric analysis was performed to determine correlation between cardiac MRE-derived MS and 1) strain, 2) relaxometry parameters, and 3) mechanical testing. Results Mean diastolic (D10: 5.09 ± 0.6 kPa; D21: 5.45 ± 0.7 kPa) and systolic (D10: 5.72 ± 0.8 kPa; D21: 6.34 ± 1.0 kPa) MS in MIR were significantly higher (P < 0.01) compared to mean diastolic (D10: 3.97 ± 0.4 kPa; D21: 4.12 ± 0.2 kPa) and systolic (D10: 5.08 ± 0.6 kPa; and D21: 5.16 ± 0.6 kPa) MS in RR. The increase in cardiac MRE-derived MS at D21 (MIR) was consistent and correlated strongly with mechanical testing-derived MS (r(diastolic) = 0.86; r(systolic) = 0.89). Diastolic MS in MIR demonstrated a negative correlation with strain (r = 0.58). Additionally, cardiac MRE-derived MS demonstrated good correlations with post-contrast T1 (r(diastolic) = –0.549; r(systolic) = –0.741) and ECV (r(diastolic) = 0.548; r(systolic) = 0.703), and no correlation with T2. Conclusion As MI progressed, cardiac MRE-derived MS increased in MIR compared to RR, which significantly correlated with mechanical testing-derived MS, T1 and ECV. Level of Evidence: 1 J. Magn. Reson. Imaging 2017;45:1024–1033

NEW FINDINGS What is the central question of this study? To what extent focal abdominal aortic aneurysmal (AAA) disease is associated with systemic remodelling of the vascular tree remains unknown. The present study examined whether anatomical differences exist between distances of the intervisceral artery origins and AAA location/size in patients with disease compared with healthy patients. What is the main finding and its importance? Intervisceral artery distances were shown to be consistently greater in AAA patients, highlighting the systemic nature of AAA disease that extends proximally to the abdominal aorta and its branches. The anatomical description of the natural variation in visceral artery origins has implications for the design of stent grafts and planning complex open aortic surgery. The initial histopathology of abdominal aortic aneurysmal (AAA) disease is atherosclerotic, later diverting towards a distinctive dilating rather than occlusive aortic phenotype. To what extent focal AAA disease is associated with systemic remodelling of the vascular tree remains unknown. The present study examined whether anatomical differences exist between the intervisceral artery origins and AAA location/size in patients with AAA disease (AAA+) relative to those without (AAA-). Preoperative contrast-enhanced computerized tomograms were reviewed in 90 consecutive AAA+ patients scheduled for open repair who underwent an infrarenal (n = 45), suprarenal (n = 26) or supracoeliac clamp (n = 19). These were compared with 39 age-matched AAA- control patients. Craniocaudal measurements were recorded from the distal origin of the coeliac artery to the superior mesenteric artery and from the origin of the superior mesenteric artery to both renal artery origins. Serial blood samples were obtained for estimation of the glomerular filtration rate before and after surgery. Intervisceral artery origins were shown to be consistently greater in AAA+ patients (P 0.05). Postoperative renal function became progressively more impaired the more proximal the clamp placement (estimated glomerular filtration rate for supracoeliac < suprarenal < infrarenal clamps, P

Purpose: To scan a volunteer population using 3.0T magnetic resonance imaging (MRI). MRI of the left ventricular (LV) structure and function in healthy volunteers has been reported extensively at 1.5T. Materials and Methods: A population of 1528 volunteers was scanned. A standardized approach was taken to acquire steady-state free precession (SSFP) LV data in the short-axis plane, and images were quantified using commercial software. Six observers undertook the segmentation analysis. Results: Mean values (±standard deviation, SD) were: ejection fraction (EF) = 69 ± 6%, end diastolic volume index (EDVI) = 71 ± 13 ml/m, end systolic volume index (ESVI) = 22 ± 7 ml/m, stroke volume index (SVI) = 49 ± 8 ml/m, and LV mass index (LVMI) = 55 ± 12 g/m. The mean EF was slightly larger for females (69%) than for males (68%), but all other variables were smaller for females (EDVI 68v77 ml/m, ESVI 21v25 ml/m, SVI 46v52 ml/m, LVMI 49v64 g/m, all P < 0.05). The mean LV volume data mostly decreased with each age decade (EDVI males: –2.9 ± 1.3 ml/m, females: –3.1 ± 0.8 ml/m; ESVI males: –1.3 ± 0.7 ml/m, females: –1.7 ± 0.5 ml/m; SVI males: –1.7 ± 0.9 ml/m, females: –1.4 ± 0.6 ml/m; LVMI males: –1.6 ± 1.1 g/m, females: –0.2 ± 0.6 g/m) but the mean EF was virtually stable in males (0.6 ± 0.6%) and rose slightly in females (1.2 ± 0.5%) with age. Conclusion: LV reference ranges are provided in this population-based MR study at 3.0T. The variables are similar to those described at 1.5T, including variations with age and gender. These data may help to support future population-based MR research studies that involve the use of 3.0T MRI scanners. J. Magn. Reson. Imaging 2016;44:1186–1196.

While there is no single diagnostic test for heart failure (HF), imaging plays a supportive role beginning with confirmation of HF, especially by detecting ventricular dysfunction (Variant 1). Ejection fraction (EF) is important in HF classification, and imaging plays a subsequent role in differentiation between HF with reduced EF (HFrEF) versus preserved EF (HFpEF) (Variant 2). Once HFrEF is identified, distinction between ischemic and nonischemic etiologies with imaging support (Variant 3) facilitates further planning. Imaging approaches which are usually appropriate include: both resting transthoracic echocardiography (TTE) and chest radiography for Variant 1; resting TTE and/or MRI (including functional, without absolute need for contrast) for Variant 2; and for Variant 3, a. Coronary CTA or coronary arteriography (if high pretest probability/symptoms for ischemic disease) for coronary assessment; b. Rest/vasodilator stress SPECT/CT, PET/CT, or MRI for myocardial perfusion assessment; c. Rest/exercise or inotropic stress TTE for myocardial contraction assessment; or d. MRI (including morphologic with contrast) for myocardial characterization. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Chronic chest pain (CCP) of a cardiac etiology is a common clinical problem. The diagnosis and classification of the case of chest pain has rapidly evolved providing the clinician with multiple cardiac imaging strategies. Though scintigraphy and rest echocardiography remain as appropriate imaging tools in the diagnostic evaluation, new technology is available. Current evidence supports the use of alternative imaging tests such as coronary computed tomography angiography (CCTA), cardiac MRI (CMRI), or Rb-82 PET/CT. Since multiple imaging modalities are available to the clinician, the most appropriate noninvasive imaging strategy will be based upon the patient's clinical presentation and clinical status. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary artery pressure (PAP), altered pulmonary artery (PA) hemodynamics, and vessel wall characteristics that affect the right ventricular (RV) function. Magnetic resonance imaging (MRI) has recently been considered in PAH and has shown promising results for estimating PAP, measuring PA hemodynamic parameters, assessing PA vessel wall stiffness, and evaluating RV global and regional functions. In this article, we review various MRI techniques and image analysis methods for evaluating PAH, with an emphasis on the resulting images and how they are interpreted for both qualitatively and quantitatively assessing the PA and RV conditions.

Introduction: In this era of rapidly expanding endovascular techniques, the use of hepatorenal bypass as treatment for a critically compromised renal perfusion has largely been forgotten. This article highlights the benefits of the technique both as a bailout strategy following complications from angioplasty and as a primary treatment in cases deemed unsuitable for endovascular intervention. Materials and Methods: Two patients are described whose renal viability was threatened by vascular compromise. One patient had a single functioning kidney with significant renal artery stenosis secondary to severe atherosclerotic disease and developed acute renal function deterioration following unsuccessful angioplasty. The second patient developed renal artery occlusion 3 years following open thoracoabdominal aortic aneurysm surgery. Both patients underwent successful hepatorenal bypass surgery and remain off dialysis 6 months after admission. Results: Both cases demonstrated the success of hepatorenal bypass with significant improvement in their renal function following open surgical repair. Conclusion: Hepatorenal bypass, although now seldom used because of available endovascular alternatives, remains an effective method of treating complicated cases of threatened kidney secondary to vascular insult.