Use of Advanced Imaging for Radiographically Occult Hip Fracture in Elderly Patients: A Systematic Review and Meta-Analysis.

Background The overall rate of hip fractures not identified on radiographs but that require surgery (ie, surgical hip fractures) remains unclear in elderly patients who are suspected to have such fractures based on clinical findings. Moreover, the importance of advanced imaging in these patients has not been comprehensively assessed. Purpose To estimate the frequency of radiographically occult hip fracture in elderly patients, to define the higher-risk subpopulation, and to determine the diagnostic performance of CT and bone scanning in the detection of occult fractures by using MRI as the reference standard. Materials and Methods A literature search was performed to identify English-language observational studies published from inception to September 27, 2018. Studies were included if patients were clinically suspected to have hip fracture but there was no radiographic evidence of surgical hip fracture (including absence of any definite fracture or only presence of isolated greater trochanter [GT] fracture). The rate of surgical hip fracture was reported in each study in which MRI was used as the reference standard. The pooled rate of occult fracture, diagnostic performance of CT and bone scanning, and strength of evidence (SOE) were assessed. Results Thirty-five studies were identified (2992 patients; mean age, 76.8 years ± 6.0 [standard deviation]; 66% female). The frequency of radiographically occult surgical hip fracture was 39% (1110 of 2835 patients; 95% confidence interval [CI]: 35%, 43%) in studies of patients with no definite radiographic fracture and 92% (134 of 157 patients; 95% CI: 83%, 98%) in studies of patients with radiographic evidence of isolated GT fracture (moderate SOE). The frequency of occult fracture was higher in patients aged at least 80 years (44%, 529 of 1184), those with an equivocal radiographic report (58%, 71 of 126), and those with a history of trauma (41%, 977 of 2370) (moderate SOE). CT and bone scanning yielded comparable diagnostic performance in the detection of radiographically occult hip fracture (P = .67), with a sensitivity of 79% and 87%, respectively (low SOE). Conclusion Elderly patients with acute hip pain and negative or equivocal findings at initial radiography have a high frequency of occult hip fractures. Therefore, the performance of advanced imaging (preferably MRI) may be clinically appropriate in all such patients. © RSNA, 2020 Online supplemental material is available for this article.

What Physicians and Health Organizations Should Know About Mandated Imaging Appropriate Use Criteria.

The Appropriate Use Criteria Program, enacted by the Centers for Medicare & Medicaid Services in response to the Protecting Access to Medicare Act of 2014 (PAMA), aims to reduce inappropriate and unnecessary imaging by mandating use of clinical decision support (CDS) by all providers who order advanced imaging examinations (magnetic resonance imaging; computed tomography; and nuclear medicine studies, including positron emission tomography). Beginning 1 January 2020, documentation of an interaction with a certified CDS system using approved appropriate use criteria will be required on all Medicare claims for advanced imaging in all emergency department patients and outpatients as a prerequisite for payment. The Appropriate Use Criteria Program will initially cover 8 priority clinical areas, including several (such as headache and low back pain) commonly encountered by internal medicine providers. All providers and organizations that order and provide advanced imaging must understand program requirements and their options for compliance strategies. Substantial resources and planning will be needed to comply with PAMA regulations and avoid unintended negative consequences on workflow and payments. However, robust evidence supporting the desired outcome of reducing inappropriate use of advanced imaging is lacking.

Duodenal emergencies: utility of multidetector CT with 2D multiplanar reconstructions for challenging but critical diagnoses.

Duodenal pathology is an infrequent cause of acute abdominal pain for which patients present to the emergency department. Critical pathology on multidetector CT (MDCT) may be overlooked if the radiologist does not carefully evaluate the duodenum as part of the search pattern. Optimal MDCT protocols include intravenous contrast with multiplanar reconstructions (MPRs). A variety of etiologies ranging from infection to malignancy can involve the duodenum, for which interrogation with MPRs is most helpful given the anatomy and complex relationship with surrounding structures. The purpose of this review article is to highlight the importance of CT acquisition with multiplanar reconstructions and review the spectrum of emergent duodenal pathology, with the goal of ensuring accurate and timely diagnosis to best guide patient management.

High-Value Multidetector CT Angiography of the Superior Mesenteric Artery: What Emergency Medicine Physicians and Interventional Radiologists Need to Know.

The superior mesenteric artery (SMA) provides vital blood supply to the midgut, and an acute abnormality can rapidly precipitate bowel ischemia and infarction and lead to morbidity and mortality. Vascular diseases that acutely compromise the SMA threaten its tributaries and include occlusion, dissection, aneurysm rupture, pseudoaneurysm, vasculitis, and SMA branch hemorrhage into the bowel. Emergency medicine physicians rely on the radiologist to identify SMA abnormalities, to characterize them, and to detail findings that guide the appropriate triage of these patients. As such, radiologists must be cognizant of the features that influence patient treatment to assist vascular surgeons and interventional radiologists in decision making. Some patients can be treated medically, while clinical and radiographic findings may suggest the need for interventional or surgical repair of the artery. In the latter case, multidetector CT findings aid in determining which of the various surgical and endovascular treatment options is optimal, and both vascular and gastrointestinal sequelae of acute SMA abnormalities contribute to these determinations. The authors review acute life-threatening conditions involving the SMA including acute occlusion, dissection, aneurysm, pseudoaneurysm, and hemorrhage and discuss the vascular and gastrointestinal multidetector CT findings in each of these conditions that help to guide surgical and interventional management. ©RSNA, 2019.

Gastric volvulus: unraveling the diagnosis with MPRs.

Gastric volvulus is a rare entity with a spectrum of acute and chronic clinical presentations. Body radiologists must be cognizant of the subtypes of gastric volvulus and identify potential complications. Mortality can be high if unrecognized from gastric necrosis, perforation, and sepsis. CT with multiplanar reformations is critical for complete evaluation beyond radiography and fluoroscopy. This article reviews clinical and imaging features of uncomplicated and complicated gastric volvulus, with the aim of guiding appropriate management.

Radiology Resident Assessment and Feedback Dashboard.

Assessment of residents is optimally performed through processes and platforms that provide daily feedback, which can be immediately acted on. Given the documentation required by the Accreditation Council for Graduate Medical Education (ACGME), effective data management, integration, and presentation are crucial to ease the burden of manual documentation and increase the timeliness of actionable information. To this end, the authors modeled the learning activities of residents using the Experience Application Programming Interface (xAPI) framework, which is a standard framework for the learning community. On the basis of the xAPI framework and using open-source software to extend their existing infrastructure, the authors developed a Web-based dashboard that provides residents with a more holistic view of their educational experience. The dashboard was designed around the ACGME radiology milestones and provides real-time feedback to residents using various assessment metrics derived from multiple data sources. The purpose of this article is to describe the dashboard's architecture and components, the design and technical considerations, and the lessons learned in implementing the dashboard. ©RSNA, 2018.

State-of-the-Art Diagnosis and Treatment of Melanoma: Optimal Multidetector Computed Tomographic Practice to Identify Metastatic Disease and Review of Innovative Therapeutic Agents.

The incidence of melanoma has risen dramatically over the past several decades. Oncologists rely on the ability of radiologists to identify subtle radiographic changes representing metastatic and recurrent melanoma in uncommon locations on multidetector computed tomography (MDCT) as the front-line imaging surveillance tool. To accomplish this goal, MDCT acquisition and display must be optimized and radiologist interpretation and search patterns must be tailored to identify the unique and often subtle metastatic lesions of melanoma. This article describes MDCT acquisition and display techniques that optimize the visibility of melanoma lesions, such as high-contrast display windows and multiplanar reconstructions. In addition, innovative therapies for melanoma, such as immunotherapy and small-molecule therapy, have altered clinical management and outcomes and have also changed the spectrum of therapeutic complications that can be detected on MDCT. Recent advances in melanoma therapy and potential complications that the radiologist can identify on MDCT are reviewed.

MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury.

Acute aortic injuries are not common in the setting of severe blunt trauma, but lead to significant morbidity and mortality. High-quality MDCT with 2D MPRs and 3D rendering are essential to identify aortic trauma and distinguish anatomic variants and other forms of aortic pathology from an acute injury. Misinterpretation of mimics of acute aortic injury can lead to unnecessary arteriography and thoracic surgery. Since most traumatic injuries occur in the distal arch, radiologists must be cognizant of the range of appearances of variants related to the ductus diverticulum. Cinematic rendering (CR) is a new 3D post-processing tool that provides even greater anatomic detail than traditional volume rendering. In this case series, CR is used to impart to radiologists a better understanding of various anatomic configurations that can be seen with a ductus diverticulum.

Evaluation of Kawasaki's disease-associated coronary artery aneurysms with 3D CT cinematic rendering.

Kawasaki's disease (KD) is a vasculitis that predominantly affects children and can lead to the development of coronary artery aneurysms. These aneurysms can subsequently thrombose and occlude, which may lead to chest pain and other signs and symptoms of acute coronary syndrome in young patients. Coronary CT angiography, including 3D visualization techniques, is a common modality used in the follow-up of KD patients. In this series of three patients, we present the typical coronary artery imaging findings that can appear in these patients, with an emphasis on the use of the novel 3D technique of cinematic rendering (CR). CR utilizes a different lighting model than other 3D methods and is able to produce highly-detailed, photorealistic images. The potential advantages of CR images in understanding the complex mediastinal vascular anatomy and the relationships of coronary artery aneurysms to other anatomic structures are emphasized.

MDCT Angiography With 3D Rendering: A Novel Cinematic Rendering Algorithm for Enhanced Anatomic Detail.

OBJECTIVE: The two most widely used postprocessing 3D tools in clinical practice are volume rendering (VR) and maximum intensity projection (MIP). With the use of current-generation MDCT, these techniques enable accurate characterization of arterial anatomy and pathology in all anatomic regions. Recently, the VR algorithm has been enhanced by the incorporation of a new lighting model. This new technique-called cinematic rendering-generates photorealistic images with the potential to more accurately depict anatomic detail. CONCLUSION: As an enhancement of the technology championed in VR, cinematic rendering promises to provide additional anatomic detail for MDCT interpretation and display. Future investigations must be conducted to evaluate the diagnostic accuracy of cinematic rendering and determine whether interpretative pitfalls result from its unique lighting model in practice.

Pulmonary CTA in sickle cell patients: quantitative assessment of enhancement quality.

PURPOSE: The purpose of this study was to validate the observation that pulmonary artery (PA) enhancement is often decreased in sickle cell disease (SCD) patients imaged with MDCT for suspected pulmonary embolism and determine whether contrast infusion parameters are accountable for lower enhancement levels. MATERIALS AND METHODS: Retrospective comparison of 35 adult SCD patients imaged for suspected pulmonary embolism (PE) in our emergency department using 128-slice dual source MDCT scanner to 34 age and weight matched adult controls. Bolus tracking data was recorded, and enhancement levels of the main PA and descending aorta were measured. Electronic records were reviewed for demographics, imaging and lab correlation, and infusion parameters. RESULTS: Age, weight, contrast infusion rate, and contrast volume were similar for both SCD and control patients. SCD patients had significantly lower main PA enhancement (mean 233 HU, range 151-361 HU) than the control subjects (mean 290 HU, range 138-487 HU) (p < 0.001). Most (74%) SCD subjects had PA enhancement that was <250 HU, while most (68%) control patients had PA enhancement ≥250 HU. Change in PA enhancement per second during bolus tracking was lower in SCD patients (12 HU/s, range -24 to 91 HU/s) than control patients (mean 30 HU/s, range -37 to 138 HU/s), although the difference was not statistically significant (p = 0.08). Hemoglobin levels were significantly lower in the SCD cohort (p < 0.001). CONCLUSION: In this series of adult SCD patients with suspected PE imaged with MDCT, main PA enhancement level was lower than controls. Quality improvement investigations should focus on protocol optimization to improve enhancement quality and likelihood of a definitive diagnosis.

Nontraumatic Subclavian Artery Abnormalities: Spectrum of MDCT Findings.

OBJECTIVE: The subclavian arteries (SCAs) may exhibit a wide spectrum of nontraumatic pathologic conditions ranging from common diseases, such as atherosclerosis, to vascular emergencies that are associated with a high morbidity and high mortality, such as type A aortic dissection and acute arterial thrombosis. MDCT angiography is an excellent modality to diagnose pathologic conditions of the SCAs. CONCLUSION: Optimization of CT acquisition protocols and interactive interpretation with 2D multiplanar reformatting and 3D rendering techniques are critical for diagnostic accuracy.

Adrenal Adenoma and Pheochromocytoma: Comparison of Multidetector CT Venous Enhancement Levels and Washout Characteristics.

PURPOSE: The aim of the study was to compare multidetector CT venous enhancement level and washout characteristics of adrenal adenoma and pheochromocytoma, with the goal of defining a venous enhancement level predictive of pheochromocytoma. METHODS: Retrospective review of medical records between 2002 and 2012 was performed to identify adrenal masses measuring less than 4 cm. Inclusion criteria for adrenal adenomas was venous phase contrast-enhanced computed tomography (CT), confirmatory adrenal CT (precontrast ± washout), 1 to 2 years stability, and absence of clinical indicators of pheochromocytoma. All pathologically proven pheochromocytomas with venous phase CT imaging were evaluated. Nodule size and attenuation (venous ± precontrast, delayed) were recorded. Student t test analysis compared venous enhancement levels. RESULTS: One hundred eighty-three subjects with 200 adenomas were compared with 22 subjects with 26 pheochromocytomas. The mean (SD) venous enhancement level for all adenomas (58 [26] Hounsfield units [HU]) and lipid-poor adenomas (76 [25]) was lower than that of pheochromocytomas (111 [38] HU, P < 0.01). No adenomas enhanced greater than 130 HU, compared with 38% (10/26) of the pheochromocytomas. A threshold of 130 HU to identify pheochromocytoma was 38% sensitive and 100% specific for pheochromocytoma. Of the 17 pheochromocytomas with washout imaging, rapid washout was identified in all (10/10, 100%) that enhanced greater than 130 HU on the venous phase, compared with 43% (3/7) that enhanced less than 130 HU. CONCLUSIONS: An indeterminate adrenal lesion that enhances greater than 130 HU on multidetector CT cannot be assumed to be an adenoma. Hypervascular pheochromocytoma (>130 HU) mimics adenoma washout pattern; absolute venous phase enhancement level must be considered.

The Role of Neoadjuvant Therapy in Characterizing Indeterminate Lung Lesions in Patients with Resectable Colorectal Liver Metastases.

BACKGROUND: Incidental pulmonary lesions are frequently found during the preoperative evaluation of patients considered for resection of colorectal liver metastases (CRLM), and their presence can confound management decisions. This study investigates the role of clinical and radiologic factors, including response to preoperative systemic chemotherapy, in determining the malignant probability of these lesions. METHODS: Computed tomography (CT) scans of 33 patients with small (≤1 cm) lung lesions undergoing resection for CRLM after preoperative chemotherapy were reviewed. Radiological features were recorded from three sequential CT scans (baseline, postchemotherapy, and follow-up). Malignancy was diagnosed either by resection or serial imaging. Chemotherapy response comparing lung lesions and CRLM was categorized as: (1) concordant or (2) discordant. Chemotherapy response, imaging features, and other clinical factors were evaluated in multivariate analyses as predictors of malignancy. RESULTS: Among the 86 indeterminate lung lesions identified, 23 % (20/86) were found to be metastases on follow-up. Lesions 6-10 mm were more likely to be metastases (odds ratio [OR] = 3.14, p = 0.045), as were lesions located in the lower lobes (OR = 4.50, p = 0.018). Concordant chemotherapy response was found in 13 of 86 (15 %) and was independently associated with metastatic disease (OR = 19.87, p < 0.001), with 11 of 13 (85 %) lesions determined to be metastases. In contrast, only 9 of 73 lesions (12 %) with discordant response were found to be metastases. CONCLUSIONS: Lesion size, location, and chemotherapy response pattern were independent predictors of malignancy for patients with resectable CRLM and small indeterminate lung lesions. Utilization of preoperative chemotherapy can be a useful method of ruling out pulmonary metastases in these patients.

Abdominal aortic aneurysms revisited: MDCT with multiplanar reconstructions for identifying indicators of instability in the pre- and postoperative patient.

Rupture of an abdominal aortic aneurysm is commonly a fatal event. Multidetector computed tomographic (CT) signs of frank aortic rupture are usually readily apparent and widely understood. However, diagnosing an impending aortic rupture on the basis of imaging findings can prove more difficult. CT is the primary modality used for serial imaging in patients with aortic aneurysm and may show findings indicative of aortic instability. Therefore, it is critical that radiologists be familiar with the CT findings of aortic instability to avert the potential complications of hemorrhage, end organ or limb ischemia, and death. Various preoperative CT indicators have been previously described in both research investigations and review articles. A large baseline aneurysm size and a rapid increase in size over time are associated with a higher risk for rupture. The importance of obtaining accurate measurements with multiplanar reconstructions and the role of new semiautomated tools for obtaining accurate, reproducible measurements are discussed. Additional CT findings that reflect aortic aneurysm instability include luminal expansion with lysis of thrombus, intramural hemorrhage (ie, the crescent sign), periaortic hemorrhage, a penetrating atherosclerotic ulcer, and contained rupture (ie, the draped aorta sign). After open or endovascular aneurysm repair, CT is routinely used to monitor for graft complications. In this setting, radiologists should understand that the presence of an endoluminal stent or surgical graft does not preclude aortic rupture. Online supplemental material is available for this article.

Arterial pseudoaneurysms complicating pancreatitis: literature review.

Arterial pseudoaneurysm formation of visceral arteries as a vascular complication of pancreatitis, either acute or chronic, is an uncommon phenomenon. This review article discusses the incidence, pathophysiology, imaging, treatment strategies, and prognosis of mesenteric pseudoaneurysms complicating pancreatitis.

Review of visceral aneurysms and pseudoaneurysms.

Abdominal aneurysms and pseudoaneurysms represent an important finding every emergency radiologist must detect. True aneurysms are usually incidental to the presenting complaint, whereas pseudoaneurysms are nearly always symptomatic. We review the demographics, pathophysiology, clinical presentation, computed tomographic appearance, treatment approaches, and prognosis of visceral aneurysms and pseudoaneurysms involving splenic, gastroduodenal, hepatic, superior mesenteric, and renal arteries.

Nuances of the unenhanced abdominal CT: careful inspection discloses critical findings.

Patients who have unenhanced abdominal CT scans are often critically ill. The unenhanced CT may reveal many unsuspected subtle abnormalities in the lower chest, abdomen, and pelvis and accordingly warrants careful attention. This article reviews unenhanced CT findings in the setting of pulmonary embolus, acute aortic syndromes, mesenteric and deep venous thrombosis, gastrointestinal hemorrhage, pancreatitis and its complications, as well as pyelonephritis.