Imaging Genomics and Multiomics: A Guide for Beginners Starting Radiomics-Based Research.

Radiomics uses advanced mathematical analysis of pixel-level information from radiologic images to extract existing information in traditional imaging algorithms. It is intended to find imaging biomarkers related to the genomics of tumors or disease patterns that improve medical care by advanced detection of tumor response patterns in tumors and to assess prognosis. Radiomics expands the paradigm of medical imaging to help with diagnosis, management of diseases and prognostication, leveraging image features by extracting information that can be used as imaging biomarkers to predict prognosis and response to treatment. Radiogenomics is an emerging area in radiomics that investigates the association between imaging characteristics and gene expression profiles. There are an increasing number of research publications using different radiomics approaches without a clear consensus on which method works best. We aim to describe the workflow of radiomics along with a guide of what to expect when starting a radiomics-based research project.

Analysis of Medical Malpractice Claims Involving Interventional Radiologists: A Comprehensive Analysis From Two National Legal Databases.

PURPOSE: The nature of lawsuits involving interventional radiologists (IRs) is not well understood. The purposes of this article are to provide an overview of the causes of action underlying medical malpractice lawsuits related to IRs and to characterize the associated factors and outcomes. METHODS: Two large legal databases were used to search for US legal cases in which there were jury awards and settlements involving IRs in the United States. Cases were screened to include only those cases in which the cause of action involved negligence on the part of IRs. RESULTS: A total of 389 published case summaries were identified, of which 93 were eligible to be included in the analysis. In 46% of the cases (43 of 93), medical malpractice was alleged against an individual IR, whereas in 43% (40 of 93), it was alleged against both an individual IR and a health care institution. Thirty-five percent of IR malpractice cases (33 of 93) involved the performance of a vascular procedure, most commonly embolization procedures (30% [n = 10]), stenting or angioplasty (21% [n = 7]), and diagnostic arteriography and angiography (18% [n = 6]). Twenty-six percent of cases (24 of 93) involved IR performance of a biopsy. Eighteen percent of cases (17 of 93) involved a failure to gain informed consent in addition to an allegation of medical negligence during treatment. Eleven percent of cases (10 of 93) were resolved by settlement, with an average settlement amount of $877,500 (range, $200,000-$2,700,000). Among the 72 cases that went to trial, 74% (53 of 72) resulted in judgments for the defendants, and 26% (19 of 72) resulted in judgements for the plaintiffs, with an average award of $2,012,243 (range, $101,667-$6,400,000). CONCLUSIONS: Vascular procedures and biopsies were the most frequent reasons for malpractice lawsuits involving IRs. Failure to gain informed consent in addition to an allegation of medical negligence during treatment was not infrequent. Although the majority of published medical malpractice claims involving IRs resulted in judgments in favor of the defendants, the average amount awarded to plaintiffs was higher compared with previous data reported for all physicians.

The Importance of Optimal Thermal Ablation Margins in Colorectal Liver Metastases: A Systematic Review and Meta-Analysis of 21 Studies.

BACKGROUND: Colorectal cancer (CRC) is the second most common cause of cancer-related deaths in the US. Thermal ablation (TA) can be a comparable alternative to partial hepatectomy for selected cases when eradication of all visible tumor with an ablative margin of greater than 5 mm is achieved. This systematic review and meta-analysis aimed to encapsulate the current clinical evidence concerning the optimal TA margin for local cure in patients with colorectal liver metastases (CLM). METHODS: MEDLINE, EMBASE, and the CENTRAL databases were systematically searched from inception until 1 May 2023, in accordance with the PRISMA Guidelines. Measure of effect included the risk ratio (RR) with 95% confidence interval (CI) using the random-effects model. RESULTS: Overall, 21 studies were included, comprising 2005 participants and 2873 ablated CLMs. TA with margins less than 5 mm were associated with a 3.6 times higher risk for LTP (n = 21 studies, RR: 3.60; 95% CI: 2.58-5.03; p-value < 0.001). When margins less than 5 mm were additionally confirmed by using 3D software, a 5.1 times higher risk for LTP (n = 4 studies, RR: 5.10; 95% CI: 1.45-17.90; p-value < 0.001) was recorded. Moreover, a thermal ablation margin of less than 10 mm but over 5 mm remained significantly associated with 3.64 times higher risk for LTP vs. minimal margin larger than 10 mm (n = 7 studies, RR: 3.64; 95% CI: 1.31-10.10; p-value < 0.001). CONCLUSIONS: This meta-analysis solidifies that a minimal ablation margin over 5 mm is the minimum critical endpoint required, whereas a minimal margin of at least 10 mm yields optimal local tumor control after TA of CLMs.

Wunderlich Syndrome: Comprehensive Review of Diagnosis and Management.

Wunderlich syndrome (WS), which was named after Carl Wunderlich, is a rare clinical syndrome characterized by an acute onset of spontaneous renal hemorrhage into the subcapsular, perirenal, and/or pararenal spaces, without a history of antecedent trauma. Patients may present with a multitude of symptoms ranging from nonspecific flank or abdominal pain to serious manifestations such as hypovolemic shock. The classic symptom complex of flank pain, a flank mass, and hypovolemic shock referred to as the Lenk triad is seen in a small subset of patients. Renal neoplasms such as angiomyolipomas and clear cell renal cell carcinomas that display an increased proclivity for hemorrhage and rupture contribute to approximately 60%-65% of all cases of WS. A plethora of renal vascular diseases (aneurysms or pseudoaneurysms, arteriovenous malformations or fistulae, renal vein thrombosis, and vasculitis syndromes) account for 20%-30% of cases of WS. Rare causes of WS include renal infections, cystic diseases, calculi, kidney failure, and coagulation disorders. Cross-sectional imaging modalities, particularly multiphasic CT or MRI, are integral to the detection, localization, and characterization of the underlying causes and facilitate optimal management. However, large-volume hemorrhage at patient presentation may obscure underlying causes, particularly neoplasms. If the initial CT or MRI examination shows no contributary causes, a dedicated CT or MRI follow-up study may be warranted to establish the cause of WS. Renal arterial embolization is a useful, minimally invasive, therapeutic option in patients who present with acute or life-threatening hemorrhage and can help avoid emergency radical surgery. Accurate diagnosis of the underlying cause of WS is critical for optimal patient treatment in emergency and nonemergency clinical settings. ©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

Image-Guided Percutaneous and Transarterial Therapies for Primary and Metastatic Lung Cancer.

Lung cancer is the leading cause of cancer mortality in the world. A significant proportion of patients with lung cancer are not candidates for surgery and must resort to other treatment alternatives. Rapid technological advancements in fields like interventional radiology have paved the way for valid treatment modalities like image-guided percutaneous and transarterial therapies for treatment of both primary and metastatic lung cancer. The rationale of ablative therapies relies on the fact that focused delivery of energy induces tumor destruction and pathological necrosis. Image-guided percutaneous thermal ablation therapies are established techniques in the local treatment of hepatic, renal, bone, thyroid, or uterine lesions. In the lung, the 3 main indications for lung ablation include local curative intent, a strategy to achieve a chemoholiday in oligometastatic disease, and recently, oligoprogressive disease. Transarterial therapies include a set of catheter-based treatments that involve delivering embolic and/or chemotherapeutic agents directed into the target tumor via the supplying arteries. This article provides a comprehensive review of the various techniques available and discusses their applications and associated complications in primary and metastatic lung cancer.

Clinical application of brain perfusion imaging in detecting stroke mimics: A review.

Stroke mimics constitute a significant proportion of patients with suspected acute ischemic stroke. These conditions may resemble acute ischemic stroke and demonstrate abnormalities on perfusion imaging sequences. The most common stroke mimics include seizure/epilepsy, migraine with aura, brain tumors, functional disorders, infectious encephalopathies, Wernicke's encephalopathy, and metabolic abnormalities. Brain perfusion imaging techniques, particularly computed tomography perfusion and magnetic resonance perfusion, are being widely used in routine clinical practice for treatment selection in patients presenting with large vessel occlusion. At the same time, the utilization of these imaging modalities enables the opportunity to better diagnose patients with stroke mimics in a time-sensitive setting, leading to appropriate management, decision-making, and resource allocation. In this review, we describe patterns of perfusion abnormalities that could discriminate patients with stroke mimics from those with acute ischemic stroke and provide specific case examples to illustrate these perfusion abnormalities. In addition, we discuss the challenges associated with interpretation of perfusion images in stroke-related pathologies. In general, perfusion imaging can provide additional information in some cases-when used in combination with conventional magnetic resonance imaging and computed tomography-and might help in detecting stroke mimics among patients who present with acute onset focal neurological symptoms.

Racial and Ethnic Disparities among Participants in Hepatocellular Carcinoma Clinical Studies Evaluating Transarterial Therapies.

PURPOSE: To evaluate the racial and ethnic representation of transarterial therapy for hepatocellular carcinoma (HCC) clinical trials in the United States. MATERIALS AND METHODS: The ClinicalTrials.gov database was examined to identify all completed studies with transarterial therapies for the management of HCC in the United States and extract information about the observed number of participants for each racial and ethnic group (based on the Office of Management and Budget definitions). The expected number of participants was calculated by multiplying the total number of participants in a trial with the U.S.-population HCC-based proportion for each group. The effects of the study phase, funding source, number of centers involved in the study, and the location of the participating center on racial and ethnic distribution were explored. RESULTS: Seventy-nine relevant studies were identified, of which 27 (34.2%) and 18 (22.8%) reported ethnic and race characteristics, respectively. Most study participants were White (81%, 1,591/1,964) by ethnicity and not Hispanic or Latino (93%, 937/1,008) by race. In terms of the observed-to-expected ratios by race and ethnicity in all trials, White and not Hispanic or Latino participants were overrepresented with a ratio of 1.22 (1.10-1.37) and 1.33 (1.26-1.41), respectively, and all other racial and ethnic groups were underrepresented. The enrollment of African Americans and Asian Americans varied by the study phase, and a higher enrollment of African Americans was noted in the National Institutes of Health-funded and multicenter studies (P < .05). CONCLUSIONS: This cross-sectional study demonstrates that in HCC transarterial therapy clinical trials, racial and ethnic minorities were underrepresented and the majority of the studies identified failed to report this demographic information.

Association of True Positivity with Serum Prostate-Specific Antigen Levels and Other Clinical Factors in Indeterminate PSMA-RADS-3A Lesions Identified on 18F-DCFPyL PET/CT Scans.

The use of prostate-specific membrane antigen targeted PET imaging for the evaluation of prostate cancer has increased significantly in the last couple of decades. When evaluating these imaging findings based on the PSMA reporting and data system version 1.0, which categorize lesions based on their likelihood of prostate cancer involvement, PSMA-RADS-3A lesions are commonly seen, which are indeterminate for the presence of disease. A total of 28 patients with 171 PSMA-RADS-3A lesions on 18F-DCFPyL PET/CT scans from June 2016 to May 2017 who had follow-up cross-sectional imaging over time were included in this study. The PSA levels of patients with PSMA-RADS-3A lesions were categorized into four groups, 0-0.2, 0.2-1, 1-2, and >2 ng/mL. The pre-operative Gleason score of these patients was categorized into two groups, Gleason score < 7 or ≥7. The median age for these patients was 72.5 years (range 59-81). The median PSA value for patients with positive lesions was significantly higher than those with negative lesions (5.8 ng/mL vs. 0.2 ng/mL, p < 0.0001). The lesion positivity rate was significantly higher in patients with PSA > 1 ng/mL (18.2% vs. 81.9%, p < 0.001). On ROC analysis, the highest classification accuracy was seen at PSA ≥ 0.6 ng/mL of 80.12% (95% CI = 73.69-86.16%), and the area under the curve was 71.32% (95% CI = 61.9-80.7%, p < 0.0001). A total of 96.4% (108/112) of patients with positive lesions and 86.4% (51/59) of patients with negative lesions had a PSMA-RADS-4/5 lymph node on the initial 18F-DCFPyL PET/CT scan (p = 0.02). In patients with a Gleason score ≥ 7, the presence of positive PSMA-RADS-3A lesions was higher, compared to negative PSMA-RADS-3A lesions (p = 0.049). Higher PSA levels in patients with PSMA-RADS-3A lesions can point towards the presence of true positivity. PSA levels may be considered in deciding whether to call an indeterminate lesion on PSMA PET.

Percutaneous Cholangioscopy for the Diagnosis and Management of Biliary Pathology in Pediatric Patients: A Single-Center Experience.

Transhepatic percutaneous cholangioscopy (PC) can be used for the diagnosis and treatment of biliary pathology. It allows for direct visualization of the biliary system to identify pathologic changes, perform biopsies, and treat biliary obstruction. The effectiveness and safety of PC in adults have been established. However, the data on the use of PC in pediatric patients are limited. In this case series, the outcomes in 4 pediatric patients (3 girls; mean age, 4 [range, 1-8] years) who underwent 6 PC procedures were examined. Three out of the 6 (50%) PC procedures were performed for diagnostic visualization of the biliary tree and/or small intestine, whereas the remaining 3 (50%) were performed for the treatment of biliary obstruction causing chronic cholestasis. The technical and procedural success rate was 100%, and no complications were encountered during or 30 days after the procedure. This study supports the feasibility and safety of PC in pediatric patients for the management of biliary pathology.

Intraarterial Therapies for the Management of Hepatocellular Carcinoma.

Image-guided locoregional therapies play a crucial role in the management of patients with hepatocellular carcinoma (HCC). Transarterial therapies consist of a group of catheter-based treatments where embolic agents are delivered directly into the tumor via their supplying arteries. Some of the transarterial therapies available include bland embolization (TAE), transarterial chemoembolization (TACE), drug-eluting beads-transarterial chemoembolization (DEB-TACE), selective internal radioembolization therapy (SIRT), and hepatic artery infusion (HAI). This article provides a review of pre-procedural, intra-procedural, and post-procedural aspects of each therapy, along with a review of the literature. Newer embolotherapy options and future directions are also briefly discussed.

Techniques for Profiling the Cellular Immune Response and Their Implications for Interventional Oncology.

In recent years there has been increased interest in using the immune contexture of the primary tumors to predict the patient's prognosis. The tumor microenvironment of patients with cancers consists of different types of lymphocytes, tumor-infiltrating leukocytes, dendritic cells, and others. Different technologies can be used for the evaluation of the tumor microenvironment, all of which require a tissue or cell sample. Image-guided tissue sampling is a cornerstone in the diagnosis, stratification, and longitudinal evaluation of therapeutic efficacy for cancer patients receiving immunotherapies. Therefore, interventional radiologists (IRs) play an essential role in the evaluation of patients treated with systemically administered immunotherapies. This review provides a detailed description of different technologies used for immune assessment and analysis of the data collected from the use of these technologies. The detailed approach provided herein is intended to provide the reader with the knowledge necessary to not only interpret studies containing such data but also design and apply these tools for clinical practice and future research studies.

Percutaneous Cryoablation for Symptomatic Peripheral Congenital Hemangioma.

Congenital hemangiomas (CHs) are rare, benign vascular tumors that are present at birth. They are divided into 3 major subtypes: rapidly involuting CHs, partially involuting CHs, and noninvoluting CHs (NICHs). There is a paucity of data in the literature regarding NICH and its management. Most symptomatic patients with NICH are managed with surgery. However, endovascular embolization, direct percutaneous sclerotherapy, or laser treatment can be used on a case-by-case basis. In this report, 3 cases with peripheral symptomatic NICH treated with percutaneous cryoablation are presented.

Image-Guided Percutaneous Ablation for Primary and Metastatic Tumors.

Image-guided percutaneous ablation methods have been further developed during the recent two decades and have transformed the minimally invasive and precision features of treatment options targeting primary and metastatic tumors. They work by percutaneously introducing applicators to precisely destroy a tumor and offer much lower risks than conventional methods. There are usually shorter recovery periods, less bleeding, and more preservation of organ parenchyma, expanding the treatment options of patients with cancer who may not be eligible for resection. Image-guided ablation techniques are currently utilized for the treatment of primary and metastatic tumors in various organs including the liver, pancreas, kidneys, thyroid and parathyroid, prostate, lung, bone, and soft tissue. This article provides a brief review of the various imaging modalities and available ablation techniques and discusses their applications and associated complications in various organs.

Gastrointestinal duplication cysts: what a radiologist needs to know.

Gastrointestinal tract duplication cysts are rare congenital malformations which can be diagnosed as early as the prenatal period but are frequently found in infancy or incidentally in adulthood. They can be seen throughout the alimentary tract with the most common involving the distal ileum and second most common the esophagus. Many duplication cysts are asymptomatic and thus discovered as an incidental imaging finding, though they can also be symptomatic with an array of clinical presentations dependent largely on their location. The vast majority of duplication cysts are benign; however, there are rare instances of malignant transformation reported. The aim of this review is to show how multimodality imaging can help in the diagnosis of duplication cysts at various anatomical locations. Duplication cyst can become symptomatic and in rare cases undergo malignant transformation; therefore, they are typically managed with surgical excision, particularly if found prenatally or during infancy. Given the diversity of anatomic locations, multiple differential diagnoses, and the need for surgical intervention, it is valuable to comprehend the role of multimodality imaging role in diagnosing duplication cysts.

Management of Patients when Superficial Venous Disease Arises from Pelvic Escape Points.

Chronic pelvic pain (CPP) is a common condition in women that carries with it significant morbidity. It is commonly seen in patients presenting to obstetrics and gynecology outpatient clinic visits. CPP is a presenting symptom of various pathologies including pelvic varicocele, pelvic adhesions, spastic colon syndrome, uterine fibroids, endometriosis, and psychosomatic disorders. Pelvic congestion syndrome has more recently been termed "pelvic venous insufficiency (PVI)" due to the underlying retrograde flow through incompetent ovarian and pelvic veins that are thought to cause the symptoms of CPP. Pelvic varices can commonly present alongside vulvar, perineal, and lower extremity varices. There are some predictable "escape pathways" for these varices that may present for interventional treatment. This article introduces the reader to current terminology, clinical presentation, diagnosis, and treatment of patients with pelvic varices due to PVI.

Temporal and geospatial variations among the interventional radiology physician workforce in the United States.

OBJECTIVE: To analyze the temporal trends and state-wide geospatial variations in Vascular and Interventional Radiology (VIR) workforce in the United States. METHODS: The State Physician Workforce Data from the AAMC website was accessed for years 2015, 2017, and 2019. The variables collected for each state included total number of active physicians, total number of physicians per specialty and total number of female physicians in VIR. Comparative data was obtained for vascular surgery (VS), diagnostic radiology (DR), and radiation oncology (RO). The annual growth rate for total physicians and sub-analysis of female physicians in each state was computed for each specialty. RESULTS: From 2015 to 2019, the total number of active physicians in the United States grew by 1.8% per year. Growth of active physicians in VIR grew by 8.3%, DR 0.06%, VS 4.4%, and RO 1.9% per year. Colorado and Minnesota had the highest growth rate for VIR physicians (15%). VIR physicians per 100,000 people increased from 0.84 (2015) to 1.10 (2019) in the US. In comparison, VS physicians increased from 0.99 (2015) to 1.14 (2019), DR physicians decreased from 8.61 (2015) to 8.43 (2019), and RO physicians grew from 1.48 (2015) to 1.56 (2019). Women represented 6.8% of the VIR workforce in the US in 2019 and increased by a rate of 16% annually in the US from 2015 to 2019. In comparison, the number of women in VS has grown by 21%, DR by 2%, and RO by 2.4% during the same period. The state of Maryland has the highest proportion of women in VIR at 18%. CONCLUSION: The number of VIR physicians is increasing at a higher rate than the national overall physician growth, and while female VIR physicians makeup a small fraction of the VIR workforce, their numbers have increased at a faster rate than overall VIR physicians.