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Purpose To determine demographics, practice patterns, needs from Society of Interventional Radiology (SIR), and preferences of interventional radiologists (IRs) early in their careers. Methods A 28-question descriptive survey was used to identify demographic and practice composition, practice issues, and needs of early career IRs. The survey was distributed to SIR members in the United States (US) (n = 859) within the first 8 years of practice, with 213 respondents (25%). Results Respondents were primarily male (n = 181, 87%), less than 40 years old (n = 156, 73%), in practice for 6 years or less (n = 167, 79%), and satisfied with IR as a career (n = 183, 92.4%). The majority were in academic practice (n = 89, 43.2%) or large private practice group (n = 67, 32.5%). Most respondents read diagnostic imaging daily or weekly (n = 130, 61%). The majority of respondents perform complex procedures regularly including transarterial tumor therapy, percutaneous tumor ablation, peripheral arterial interventions, and biliary interventions monthly. Many respondents (n = 49, 23%) have changed jobs at least once citing career advancement, practice issues/disagreements, or compensation as reason. Most respondents would serve as mentors (n = 170, 80%) for trainees and were satisfied with their career mentorship (n = 166, 78%). Respondents felt that mentorship, identification of barriers facing early career IRs, and networking should be the most important functions of the Early Career Section (ECS)of the SIR. Conclusion As nearly all survey respondents indicated that early career IRs have different needs and priorities than established physicians, they felt that mentorship, identification of barriers facing early career IRs, and networking should be the most important functions of the ECS. Additionally, this same group of IRs report low comfort with the business side of medicine and may benefit from directed content provided by the SIR ECS.

The recognition of pain and the treatments used for it are vital for all practitioners. Many types of pain can be treated in a locoregional fashion, which has significant implications not just for any individual patient but for society as a whole. These treatments are most effective when performed in a minimally invasive, image-guided fashion. Interventional radiologists should play a central role in providing these lifestyle-limiting treatments. This article describes the medications most typically used for spinal and extra-axial treatments in the management of patients in pain.

Female physicians in academic medicine have faced barriers that potentially affect representation in different fields and delay promotion. Little is known about gender representation differences in United States academic radiology departments, particularly within the most pursued subspecialties.To determine whether gender differences exist in United States academic radiology departments across seven subspecialties with respect to academic ranks, departmental leadership positions, experience, and scholarly metrics.In this cross-sectional study from November 2018 to June 2020, a database of United States academic radiologists at 129 academic departments in seven subspecialties was created. Each radiologist's academic rank, departmental leadership position (executive-level - Chair, Director, Chief, and Department or Division Head vs vice-level - vice, assistant, or associate positions of executive level), self-identified gender, years in practice, and measures of scholarly productivity (number of publications, citations, and h-index) were compiled from institutional websites, Doximity, LinkedIn, Scopus, and official NPI profiles. The primary outcome, gender composition differences in these cohorts, was analyzed using ChiOverall, 5086 academic radiologists (34.7% women) with a median 14 years of practice (YOP) were identified and indexed. There were 919 full professors (26.1% women, p0.01) and 1055 executive-level leadership faculty (30.6% women, p0.01). Within all subspecialties except breast imaging, women were in the minority (35.4% abdominal, 79.1% breast, 12.1% interventional, 27.5% musculoskeletal, 22.8% neuroradiology, 45.1% pediatric, and 19.5% nuclear; p0.01). Relative to subspecialty gender composition, women full professors were underrepresented in abdominal, pediatric, and nuclear radiology (p0.05) and women in any executive-level leadership were underrepresented in abdominal and nuclear radiology (p0.05). However, after adjusting for h-index and YOP, gender did not influence rates of professorship or executive leadership. The strongest single predictors for professorship or executive leadership were h-index and YOP.Women academic radiologists in the United States are underrepresented among senior faculty members despite having similar levels of experience as men. Gender disparities regarding the expected number of women senior faculty members relative to individual subspecialty gender composition were more pronounced in abdominal and nuclear radiology, and less pronounced in breast and neuroradiology. Overall, h-index and YOP were the strongest predictors for full-professorship and executive leadership among faculty.● Though women comprise 34.7% of all academic radiologists, women are underrepresented among senior faculty members (26.1% of full professors and 30.6% of executive leadership) ● Women in junior faculty positions had higher median years of practice than their male counterparts (10 vs 8 for assistant professors, 21 vs 13 for vice leadership) ● Years of practice and h-index were the strongest predictors for full professorship and executive leadership.

Background: Prolonged dwell time of inferior vena cava (IVC) filter has shown to increase the need for the use of complex IVC filter retrieval techniques. Here we report complex retrieval of IVC filter with prolonged dwelling time which was temporarily associated with severe bradycardia and hypotension. Case Presentation: 59 years old male patient with past medical history of morbid obesity, atrial fibrillation status post ablation, obstructive sleep apnea and end-stage renal disease presented for IVC filter retrieval. When IVC filter was covered by sheaths and IVC was temporarily collapsed/occluded, the patient developed severe bradycardia and hypotension without compensatory tachycardia. Contrast injection through the common femoral vein sheath showed complete occlusion of IVC while IVC filter was covered by both sheaths likely due to embedment of the IVC filter in the wall by extensive fibrinous tissues. IVF filter was successfully retrieved, and the blood pressure and heart rate were improved immediately afterward. A large non occlusive IVC thrombus was identified on the final venogram, which was aspirated using mechanical thrombectomy device. Conclusion: Complex retrieval of IVC filter with prolonged dwelled time can result in acute severe bradycardia and hypotension due to vasovagal reaction and/or acute collapse/occlusion of IVC in setting of IVC filter adhesion/embedment in the wall by extensive fibrinous tissues.

Thoughtful and accurate dosimetry is critical to obtain the safest and most efficacious yttrium-90 (Y90) radioembolization of primary and secondary liver cancers. Three dosimetry models are currently used in clinical practice, namely, body surface area model, medical internal radiation dose model, and the partition model. The objective of this review is to briefly outline the history behind Y90 dosimetry and the difference between the aforementioned models. When applying these three models to a single case, the differences between them are further demonstrated. Each dosimetry model in clinical practice has its own benefits and limitations. Therefore, it is incumbent upon practicing interventional radiologists to be aware of these differences to optimize treatment outcomes for their patients.

Cirrhosis is a heterogeneous disease that cannot be studied as a single entity and is classified in two main prognostic stages: compensated and decompensated cirrhosis. Portal hypertension, characterized by a pathological increase of the portal pressure and by the formation of portal-systemic collaterals that bypass the liver, is the initial and main consequence of cirrhosis and is responsible for the majority of its complications. A myriad of treatment options exists for appropriately managing the most common complications of portal hypertension, including acute variceal bleeding and refractory ascites. 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.

Nontraumatic aortic disease can be caused by a wide variety of disorders including congenital, inflammatory, infectious, metabolic, neoplastic, and degenerative processes. Imaging examinations such as radiography, ultrasound, echocardiography, catheter-based angiography, CT, MRI, and nuclear medicine examinations are essential for diagnosis, treatment planning, and assessment of therapeutic response. Depending upon the clinical scenario, each of these modalities has strengths and weaknesses. Whenever possible, the selection of a diagnostic imaging examination should be based upon the best available evidence. 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 purpose of this document is to assist physicians select the most appropriate diagnostic imaging examination for nontraumatic aortic diseases.

Lymphatics have long been overshadowed by the remainder of the circulatory system. Historically, lymphatics were difficult to study because of their small and indistinct vessels, colorless fluid contents, and limited effective interventions. However, the past several decades have brought increased funding, advanced imaging technologies, and novel interventional techniques to the field. Understanding the history of lymphatic anatomy and physiology is vital to further realize the role lymphatics play in most major disease pathologies and innovate interventional solutions for them.

Post-operative lymphatic injuries are uncommon but increase morbidity and mortality in vulnerable patient populations. Post-surgical lymphatic leaks are most commonly a consequence of radical neck dissection, esophagectomy, and lung cancer resections or retroperitoneal surgeries such as radical nephrectomy and lymphadenectomy. Injury may occur anywhere along the lymphatic chains with most serious leaks occurring along the axial skeleton between the inguinal region and the left venous angle. The resultant clinical manifestations of a lymphatic leak are dependent on the location and severity of the lymphatic injury as well as patient factors. Treatment strategies are tailored toward the causative etiology, symptom severity, and daily leak volume with higher volume leaks warranting a more aggressive approach. Lymphangiography and lymphatic interventions, such as embolization, are increasingly applied for both the diagnosis and as a minimally invasive therapy for lymphatic injuries. Herein, a review of lymphatic anatomy, lymphangiography, and lymphatic interventions for the treatment of post-operative chylothorax, chylous ascites, and lymphocele is presented.

Purpose Predictive 3-dimensional dosimetry requires spatial concordance between diagnostic and therapeutic activity distributions. We assess similarity between theranostic pairs ( 99m Tc–macroaggregated albumin [MAA] single photon emission computed tomography [SPECT] and 90 Y microsphere positron emission tomography [PET]) in patients using criteria that account for spatial resolution differences and misregistration. Methods and Materials Phantom-based acceptance criteria were determined using a liver phantom filled with 99m Tc and 90 YCl 3 and scanned with SPECT/computed tomography [CT] and PET/CT, respectively. Gaussian blurring was applied to PET to match 99m Tc phantom scan image quality. After rigid registration between SPECT/CT and PET/CT, perturbations up to ±3 voxels were applied to determine the similarity metric (SM) sensitivity. 99m Tc-MAA SPECT/CT and 90 Y microsphere PET/CT image pairs/patients (n = 23) were processed analogously. SMs calculated included the Pearson correlation coefficient ( ρ r ), Lin's concordance correlation coefficient ( ρ c ), Spearman's rank correlation coefficient ( ρ s ), the mean squared difference, and the Dice similarity coefficient (DSC). Patient-specific acceptance criteria were determined by evaluating the SMs of the blurred PET compared with itself misregistered. Results After transforming PET to SPECT resolution, high similarity was found in phantom, with ρ c , ρ r , ρ s > 0.98 ± 0.01, a mean squared difference of (4.1 ± 0.3) × 10 −4 and DSC > 0.85 ± 0.01 for investigated thresholds (5%, 30%, and 50%). SMs for patients varied from poor to good. A small percentage (13%-30%) of patient scans were acceptable using phantom-based acceptance criteria. The percentage increased slightly (17%-35%) using patient-specific acceptance criteria. DSC for most patients were substantially lower (average 0.95 vs 0.61 for 5% threshold) than phantom values. Conclusions At best, 35% of patients had an SM within the acceptance criteria established to account for imaging-related effects impacting spatial concordance between 99m Tc-MAA SPECT and 90 Y PET. Additional clinical factors should be evaluated in the future. The procedure of accounting for image-related effects when assessing spatial concordance can be applied to other theranostic pairs.

A broad range of nonatherosclerotic diseases affect the peripheral arteries. The appropriate initial diagnostic imaging studies vary, depending upon the clinical presentation and suspicion of disease. Accurate vascular imaging relies upon visualization of the vessel lumen, vessel wall, and surrounding soft-tissue structures, with some modalities also offering the ability to characterize blood flow direction and velocity. Furthermore, nonvascular findings are often paramount in supporting a suspected clinical syndrome or guiding surgical management. The scenarios discussed in this document include the initial evaluation of suspected popliteal entrapment syndrome, external iliac artery endofibrosis, lower-extremity inflammatory vasculitides, dissection or connective tissue disease, noninflammatory vascular disease, and vascular trauma. 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.

Abdominal aortic aneurysm (AAA) is defined as aneurysmal dilation of the abdominal aorta to 3 cm or greater. A high degree of morbidity and mortality is associated with AAA rupture, and imaging surveillance plays an essential role in mitigating the risk of rupture. Aneurysm size and growth rate are factors associated with the risk of rupture, thus surveillance imaging studies must be accurate and reproducible to characterize aneurysm size. Ultrasound, CT angiography, and MR angiography provide an accurate and reproducible assessment of size, while radiographs and aortography provide limited evaluation. 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.

Interventional Radiology (IR) was officially approved by the American Board of Medical Specialties in 2012 and the Accreditation Council of Graduate Medical Education as a unique, integrated residency in 2014. Its establishment and distinction from diagnostic radiology was compelled by the increasing emphasis on clinical care delivery by IRs. The shift in the IR training paradigm, as exemplified in the Integrated IR residency programs, appeals to a distinct cohort of applicants, prompting the need to re-evaluate the recruitment and selection process. This article discusses selection criteria for identifying ideal candidates for the new IR training model (focusing on Integrated IR residency training), highlights the importance of collaboration between the IR and DR selection committees, and illustrates the changes made at a single institution over the course of 4 selection cycles prior to the COVID-19 pandemic as well as significant changes in the current climate of the global pandemic.

Lymphangiography as a diagnostic procedure dates back to the 1950s and was widely performed for several decades until being supplanted by other advanced imaging techniques. With the advent of thoracic duct embolization to treat chylothorax, Constantin Cope ushered in a transition from lymphangiography as a diagnostic procedure to a precursor for lymphatic intervention. Subsequently, technical modifications and applications of lymphatic embolization to other medical conditions have greatly expanded the scope and application of lymphangiography and lymphatic intervention. Although there is increasing familiarity with lymphatic interventions, few interventionalists have performed a high enough volume to be aware of potential complications and their management. Potential complications of lymphangiography and those encountered while performing lymphatic interventions are discussed along with approaches to minimize their risk and management strategies should they occur.

Traumatic chylothorax occurs more often now than in historic reports. In part, this is due to the increased ability to perform more advanced and aggressive thoracic resections and cardiovascular surgeries as well as the improved mortality of cancer patients. If untreated, chylothorax can result in significant morbidity and mortality, particularly in patients with underlying malignancy. Thoracic duct embolization for chylothorax was the first successful lymphatic intervention and has been performed for over 20 years. An overview of the clinical and technical approach to thoracic duct embolization for traumatic chylothorax is presented in addition to a review of outcomes.

To evaluate the efficacy and safety of Y90 radiation segmentectomy (RS) vs. percutaneous microwave ablation (MWA) in patients with solitary HCC ≤ 4 cm.From 2014 to 2017, 68 consecutive treatment naïve patients were included (34 per treatment arm). Chi-square and t-test were used to evaluate differences in baseline demographics between groups. Objective response was evaluated using mRECIST and toxicity using CTCAE. Overall survival (OS) and progression free survival (PFS) in the targeted tumor and the remainder of liver from initial treatment was calculated using Kaplan-Meier estimation. Propensity score matching was then performed with n = 24 patients matched in each group. Similar outcome analysis was then pre-formed.In the overall study population, both groups had similar baseline characteristics with the exception of larger lesions in the RS group. There was no difference in toxicity, objective tumor response, OS and non-target liver PFS between the MWA and RS group (p's 0.05). In the matched cohort, the objective tumor response was 82.6% in MWA vs. 90.9%% in RS (p = 0.548). The mean OS in the MWA group (44.3 months) vs RS (59.0 months; p = 0.203). The targeted tumor mean PFS for the MWA groups was 38.6 months vs. 57.8 months in RS group (p = 0.005). There was no difference overall PFS and toxicity between the 2 matched groups.Our data suggest Y90 RS achieves similar tumor response and OS with a similar safety compared to MWA in the management of HCC lesions ≤ 4 cm. Additionally, targeted tumor PFS appears to be prolonged in the RS group with similar non-target liver PFS between RS and MWA group.

Trauma remains one of the leading causes of death in the United States in patients younger than 45 years. Blunt trauma is most commonly a result of high-speed motor vehicular collisions or high-level fall. The liver and spleen are the most commonly injured organs, with the liver being the most commonly injured organ in adults and the spleen being the most affected in pediatric blunt trauma. Liver injuries incur a high level of morbidity and mortality mostly secondary to hemorrhage. Over the past 20 years, angiographic intervention has become a mainstay of treatment of hepatic trauma. As there is an increasing need for the interventional radiologists to embolize active hemorrhage in the setting of blunt and penetrating hepatic trauma, this article aims to review the current level of evidence and contemporary management of hepatic trauma from the perspective of interventional radiologists. Embolization techniques and associated outcome and complications are also reviewed.

A bleeding patient is a common consult for interventional radiologists. Prompt triage, preprocedural evaluation specific to the site of hemorrhage, and knowledge of resuscitative strategies allow for a potentially life-saving procedure to be appropriately and safely performed. Having a firm understanding of the clinical work-up and management of a bleeding patient has never been more important. In this article, a discussion of the clinical approach and work-up of a bleeding patient for whom interventional radiology is consulted is followed by a discussion of etiology-specific preprocedural work-up.

We report two cases of peripartum ruptured ovarian artery aneurysms (OAA). One patient was treated through endovascular embolization and the other with percutaneous thrombin injection. Multiple additional unruptured OAAs were incidentally discovered in each patient. We describe the pathophysiologic basis for OAA rupture, approaches to treatment, and suggest management strategies for incidentally discovered ovarian aneurysms.

Peripheral arterial disease (PAD) affects millions across the world and in the United States between 9% to 23% of all patients older than 55 years. The refinement of surgical techniques and evolution of endovascular approaches have improved the success rates of revascularization in patients afflicted by lower extremity PAD. However, restenosis or occlusion of previously treated vessels remains a pervasive issue in the postoperative setting. A variety of different imaging options are available to evaluate patients and are reviewed within the context of asymptomatic and symptomatic patients with PAD who have previously undergone endovascular or surgical revascularization. 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.

Inferior vena cava filter (IVCF) placement is indicated in patients with acute venous thromboembolism who cannot be adequately anticoagulated or have failed anticoagulation. Prompt IVCF retrieval decreases the risk of complications associated with longer dwell times including fracture, penetration, and further thromboembolic events. Endovascular IVCF retrieval has been performed despite penetration into adjacent structures including the aorta; however, penetration into the false lumen of an aortic dissection is rarely seen. This case report describes endovascular management of an 11 year old IVCF that caused iliocaval thrombosis and penetrated the false lumen of a chronic type B aortic dissection.

Purpose In 90Y microsphere radioembolization (RE), accurate post-therapy imaging-based dosimetry is important for establishing absorbed dose versus outcome relationships for developing future treatment planning strategies. Additionally, accurately assessing microsphere distributions is important because of concerns for unexpected activity deposition outside the liver. Quantitative 90Y imaging by either SPECT or PET is challenging. In 90Y SPECT model based methods are necessary for scatter correction because energy window-based methods are not feasible with the continuous bremsstrahlung energy spectrum. The objective of this work was to implement and evaluate a scatter estimation method for accurate 90Y bremsstrahlung SPECT/CT imaging. Methods Since a fully Monte Carlo (MC) approach to 90Y SPECT reconstruction is computationally very demanding, in the present study the scatter estimate generated by a MC simulator was combined with an analytical projector in the 3D OS-EM reconstruction model. A single window (105 to 195-keV) was used for both the acquisition and the projector modeling. A liver/lung torso phantom with intra-hepatic lesions and low-uptake extra-hepatic objects was imaged to evaluate SPECT/CT reconstruction without and with scatter correction. Clinical application was demonstrated by applying the reconstruction approach to 5 patients treated with RE to determine lesion and normal liver activity concentrations using a (liver) relative calibration. Results There was convergence of the scatter estimate after just 2 updates, greatly reducing computational requirements. In the phantom study, compared with reconstruction without scatter correction, with MC scatter modeling there was substantial improvement in activity recovery in intra-hepatic lesions (from > 55% to > 86%), normal liver (from 113% to 104%) and lungs (from 227% to 104%) with only a small degradation in noise (13% vs. 17%). Similarly, with scatter modeling contrast improved substantially both visually and in terms of a detectability index, which was especially relevant for the low uptake extra-hepatic objects. The trends observed for the phantom were also seen in the patient studies where lesion activity concentrations and lesion-to-liver concentration ratios were lower for SPECT without scatter correction compared with reconstruction with just two MC scatter updates: in eleven lesions the mean uptake was 4.9 vs. 7.1 MBq/mL (P=0.0547), the mean normal liver uptake was 1.6 vs. 1.5 MBq/mL (P = 0.056) and the mean lesion-to-liver uptake ratio was 2.9 vs. 4.2 (P=0.0402) for reconstruction without and with scatter correction, respectively. Conclusions Quantitative accuracy of 90Y bremsstrahlung imaging can be substantially improved with MC scatter modeling without significant degradation in image noise or intensive computational requirements. This article is protected by copyright. All rights reserved.

Percutaneous image-guided ablation is performed throughout many areas of the body for various pathologies including hepatic malignancies. Heat and cold-based ablative technologies are effective and well-tolerated with an acceptable safety profile. However, ablative therapies may be technically more challenging and cause collateral thermal injury if the targeted lesion is adjacent to critical organs. Previously, techniques including artificial ascites and pneumoperitoneum have been utilized to displace or insulate critical structures from the ablation zone. This technical innovation describes (10-30 mL) fibrillar collagen dissolved in fluid as a focal thermal insulation technique. Small volume fibrillar collagen instillation, and thermal ablation were technically successful in three cases without complication. Clinical follow-up and 3-month imaging confirmed complete ablation of all hepatic malignancies without collateral injury.

Clinical palpation of a pulsating abdominal mass alerts the clinician to the presence of a possible abdominal aortic aneurysm (AAA). Imaging studies are important in diagnosing and categorizing the extent of the aneurysm and may aid in treatment planning. The consensus of the literature supports the use of ultrasound as the initial screening test in patients with suspected AAA. Population-based ultrasound screening studies have been recommended and have proved effective for male patients > 65 years of age. For diagnosis and pre-intervention evaluation, either multidetector CT or CT angiography is the optimal choice for detailed characterization of the aneurysm. MR angiography may be substituted if CT cannot be performed (for example, because the patient is allergic to iodinated contrast material). Invasive angiography has little role in the diagnosis of AAA and PET and CT remain experimental in patients with suspected aneurysms. The ACR 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.

Chylothorax is an uncommon but serious medical condition, which arises when intestinal lymphatic fluid leaks into the pleural space. Treatment strategies depend on the daily output and underlying etiology, which may be due to direct injury to lymphatic vessels or a nontraumatic disorder. Chest radiographs confirm the presence of pleural fluid and lateralize the process. In the setting of direct injury, lymphangiography can often be both diagnostic and facilitate a minimally invasive attempt at therapy. CT and MRI in this setting may be appropriate for cases when lymphangiography is not diagnostic. When the etiology is nontraumatic or unknown, CT or MRI can narrow the differential diagnosis, and lymphangiography is useful if a minimally invasive approach to treatment is desired. 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.

Acute limb ischemia (ALI) requires urgent diagnosis and treatment to prevent limb loss. Invasive digital subtraction arteriography (DSA) is the gold standard for diagnosing ALI. DSA is the only diagnostic modality that permits simultaneous treatment of acute arterial occlusion. Noninvasive imaging with MRA or CT angiography may also be appropriate before treatment, especially when the diagnosis of ALI is in doubt or where DSA is unavailable. Other imaging and noninvasive physiologic tests may prove important for longer term management but are less recommended in the acute setting. 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.

N-butyl cyanoacrylate glue is well established as a transcatheter or direct injection embolic agent. Herein, targeted glue embolization was performed by direct needle injection into peripheral portal branches and along the surface of the liver to directly treat actively extravasating portal venous injury. In both cases, hemodynamically unstable patients underwent exploratory laparotomy, which was not able to definitively treat the hemorrhage. Subsequently, emergent visceral angiography and indirect portography revealed active portal phase extravasation. Transhepatic direct needle injection of the peripheral portal active extravasation with glue was successful in both cases and the patients stabilized, demonstrating this as an efficacious salvage approach.