Advancements in Neuroendocrine Neoplasms: Imaging and Future Frontiers.

Neuroendocrine neoplasms (NENs) are a diverse group of tumors with varying clinical behaviors. Their incidence has risen due to increased awareness, improved diagnostics, and aging populations. The 2019 World Health Organization classification emphasizes integrating radiology and histopathology to characterize NENs and create personalized treatment plans. Imaging methods like CT, MRI, and PET/CT are crucial for detection, staging, treatment planning, and monitoring, but each of them poses different interpretative challenges and none are immune to pitfalls. Treatment options include surgery, targeted therapies, and chemotherapy, based on the tumor type, stage, and patient-specific factors. This review aims to provide insights into the latest developments and challenges in NEN imaging, diagnosis, and management.

Renal bleeding: imaging and interventions in patients with tumors.

In patients with cancer, spontaneous renal bleeding can stem from a range of underlying factors, necessitating precise diagnostic tools for effective patient management. Benign and malignant renal tumors are among the primary culprits, with angiomyolipomas and renal cell carcinomas being the most common among them. Vascular anomalies, infections, ureteral obstructions, and coagulation disorders can also contribute to renal-related bleeding. Cross-sectional imaging techniques, particularly ultrasound and computed tomography (CT), play pivotal roles in the initial detection of renal bleeding. Magnetic resonance imaging and CT are preferred for follow-up evaluations and aid in detecting underlying enhancing masses. IV contrast-enhanced ultrasound can provide additional information for active bleeding detection and differentiation. This review article explores specific disorders associated with or resembling spontaneous acute renal bleeding in patients with renal tumors; it focuses on the significance of advanced imaging techniques in accurately identifying and characterizing renal bleeding in these individuals. It also provides insights into the clinical presentations, imaging findings, and treatment options for various causes of renal bleeding, aiming to enhance the understanding, diagnosis, and management of the issue.

Cholangiocarcinoma imaging: from diagnosis to response assessment.

Cholangiocarcinoma (CCA), a highly aggressive primary liver cancer arising from the bile duct epithelium, represents a substantial proportion of hepatobiliary malignancies, posing formidable challenges in diagnosis and treatment. Notably, the global incidence of intrahepatic CCA has seen a rise, necessitating a critical examination of diagnostic and management strategies, especially due to presence of close imaging mimics such as hepatocellular carcinoma (HCC) and combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA). Hence, it is imperative to understand the role of various imaging modalities such as ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), elucidating their strengths, and limitations in diagnostic precision and staging accuracy. Beyond conventional approaches, there is emerging significance of functional imaging tools including positron emission tomography (PET)-CT and diffusion-weighted (DW)-MRI, providing pivotal insights into diagnosis, therapeutic assessment, and prognostic evaluation. This comprehensive review explores the risk factors, classification, clinical features, and role of imaging in the holistic spectrum of diagnosis, staging, management, and restaging for CCA, hence serving as a valuable resource for radiologists evaluating CCA.

An Illustrated Review of the Recent 2019 World Health Organization Classification of Neuroendocrine Neoplasms: A Radiologic and Pathologic Correlation.

ABSTRACT: Recent advances in molecular pathology and an improved understanding of the etiology of neuroendocrine neoplasms (NENs) have given rise to an updated World Health Organization classification. Since gastroenteropancreatic NENs (GEP-NENs) are the most common forms of NENs and their incidence has been increasing constantly, they will be the focus of our attention. Here, we review the findings at the foundation of the new classification system, discuss how it impacts imaging research and radiological practice, and illustrate typical and atypical imaging and pathological findings. Gastroenteropancreatic NENs have a highly variable clinical course, which existing classification schemes based on proliferation rate were unable to fully capture. While well- and poorly differentiated NENs both express neuroendocrine markers, they are fundamentally different diseases, which may show similar proliferation rates. Genetic alterations specific to well-differentiated neuroendocrine tumors graded 1 to 3 and poorly differentiated neuroendocrine cancers of small cell and large-cell subtype have been identified. The new tumor classification places new demands and creates opportunities for radiologists to continue providing the clinically most relevant report and on researchers to design projects, which continue to be clinically applicable.

Society of Radiologists in Ultrasound Consensus Conference Recommendations for Incidental Gallbladder Polyp Management: Interreader Agreement Among 10 Radiologists.

BACKGROUND. The 2022 Society of Radiologists in Ultrasound (SRU) consensus conference recommendations for small gallbladder polyps support management that is less aggressive than earlier approaches and may help standardize evaluation of polyps by radiologists. OBJECTIVE. The purpose of the present study was to assess the interreader agreement of radiologists in applying SRU recommendations for management of incidental gallbladder polyps on ultrasound. METHODS. This retrospective study included 105 patients (75 women and 30 men; median age, 51 years) with a gallbladder polyp on ultrasound (without features highly suspicious for invasive or malignant tumor) who underwent cholecystectomy between January 1, 2003, and January 1, 2021. Ten abdominal radiologists independently reviewed ultrasound examinations and, using the SRU recommendations, assessed one polyp per patient to assign risk category (extremely low risk, low risk, or indeterminate risk) and make a possible recommendation for surgical consultation. Five radiologists were considered less experienced (< 5 years of experience), and five were considered more experienced (≥ 5 years of experience). Interreader agreement was evaluated. Polyps were classified pathologically as nonneoplastic or neoplastic. RESULTS. For risk category assignments, interreader agreement was substantial among all readers (k = 0.710), less-experienced readers (k = 0.705), and more-experienced readers (k = 0.692). For surgical consultation recommendations, inter-reader agreement was substantial among all readers (k = 0.795) and more-experienced readers (k = 0.740) and was almost perfect among less-experienced readers (k = 0.811). Of 10 readers, a median of 5.0 (IQR, 2.0-8.0), 4.0 (IQR, 2.0-7.0), and 0.0 (IQR, 0.0-0.0) readers classified polyps as extremely low risk, low risk, and indeterminate risk, respectively. Across readers, the percentage of polyps classified as extremely low risk ranged from 32% to 72%; as low risk, from 24% to 65%; and as indeterminate risk, from 0% to 8%. Of 10 readers, a median of zero change to 0 (IQR, 0.0-1.0) readers recommended surgical consultation; the percentage of polyps receiving a recommendation for surgical consultation ranged from 4% to 22%. Of a total of 105 polyps, 102 were nonneo-plastic and three were neoplastic (all benign). Based on readers' most common assessments for nonneoplastic polyps, the risk category was extremely low risk for 53 polyps, low risk for 48 polyps, and indeterminate risk for one polyp; surgical consultation was recommended for 16 polyps. CONCLUSION. Ten abdominal radiologists showed substantial agreement for polyp risk categorizations and surgical consultation recommendations, although areas of reader variability were identified. CLINICAL IMPACT. The findings support the overall reproducibility of the SRU recommendations, while indicating opportunity for improvement.

Imaging of Urinary Bladder and Ureteral Endometriosis with Emphasis on Diagnosis and Technique.

Endometriosis is a chronic inflammatory gynecological condition affecting 10-15% of women in the reproductive age group. The urinary tract is the second most common extragenital organ system affected by endometriosis, and the urinary bladder and ureter are the two most common sites involved. Involvement of the urinary bladder can cause chronic debilitating symptoms, whereas ureteral involvement may lead to asymptomatic loss of renal function. Both conditions are frequently unsuspected, leading to a delay in diagnosis. Therefore, it is important to recognize this entity early, for which knowledge of imaging appearances and techniques is helpful. In this review article, we describe (a) endometriosis background, pathogenesis, definitions and clinical symptoms, (b) imaging appearance, with emphasis on ultrasound and MRI findings of urinary bladder and ureteric endometriosis, (c) ultrasound technique and MRI sequences useful for making the correct diagnosis, (d) overview of the treatment options and key imaging findings that are important to the surgeon for surgical planning, and (e) a structured reporting template useful for multidisciplinary patient management.

Understanding the role of radiologists in complex treatment decisions for patients with hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver and represents a significant global health burden. Management of HCC can be challenging due to multiple factors, including variable expectations for treatment outcomes. Several treatment options are available, each with specific eligibility and ineligibility criteria, and are provided by a multidisciplinary team of specialists. Radiologists should be aware of the types of treatment options available, as well as the criteria guiding the development of individualized treatment plans. This awareness enables radiologists to contribute effectively to patient-centered multidisciplinary tumor boards for HCC and play a central role in reassessing care plans when the treatment response is deemed inadequate. This comprehensive review aims to equip radiologists with an overview of HCC staging systems, treatment options, and eligibility criteria. The review also discusses the significance of imaging in HCC diagnosis, treatment planning, and monitoring treatment response. Furthermore, we highlight the crucial branch points in the treatment decision-making process that depend on radiological interpretation.

Transjugular Intrahepatic Portosystemic Shunt and Thrombectomy (TIPS-Thrombectomy) for Symptomatic Acute Noncirrhotic Portal Vein Thrombosis.

PURPOSE: To report the safety and effectiveness of transjugular intrahepatic portosystemic shunt and mechanical thrombectomy (TIPS-thrombectomy) for symptomatic acute noncirrhotic portal vein thrombosis (NC-PVT). MATERIALS AND METHODS: Patients with acute NC-PVT who underwent TIPS-thrombectomy between 2014 and 2021 at a single academic medical center were retrospectively reviewed. Thirty-two patients were included (men, 56%; median age, 51 years [range, 39-62 years]). The causes for PVT included idiopathic (n = 12), prothrombotic disorders (n = 11), postsurgical sequelae (n = 6), pancreatitis (n = 2), and Budd-Chiari syndrome (n = 1). The indications for TIPS-thrombectomy included refractory abdominal pain (n = 14), intestinal venous ischemia (n = 9), ascites (n = 4), high-risk varices (n = 3), and variceal bleeding (n = 2). Variables studied included patient, disease, and procedure characteristics. Patients were monitored over the course of 1-year follow-up. RESULTS: Successful recanalization of occluded portal venous vessels occurred in all 32 patients (100%). Compared with pretreatment patency, recanalization with TIPS-thrombectomy resulted in an increase in patent veins (main portal vein [28% vs 97%, P < .001], superior mesenteric vein [13% vs 94%, P < .001], and splenic vein [66% vs 91%, P < .001]). Three procedure-related adverse events occurred (Society of Interventional Radiology grade 2 moderate). Hepatic encephalopathy developed in 1 (3%) of 32 patients after TIPS placement. At 1-year follow-up, return of symptoms occurred in 3 (9%) of 32 patients: (a) ascites (n = 1), (b) variceal bleeding (n = 1), and (c) intestinal venous ischemia (n = 1). The intention-to-treat 1-year portal vein and TIPS primary and secondary patency rates were 78% (25/32) and 100% (32/32), respectively. Seven patients required additional procedures, and the 1-year mortality rate was 3% (1/32). CONCLUSIONS: TIPS-thrombectomy is a safe and effective method for treating patients with symptomatic acute NC-PVT.

Imaging modalities and optimized imaging protocols in pregnant patients with cancer.

Medical imaging during pregnancy may be necessary to diagnose conditions that affect the outcome of the mother and fetus. Diagnosis and staging of cancer in pregnant women can be particularly challenging due to fear of inherent risk to the fetus, lack of standardized imaging protocols, and ethical challenges posed while choosing the best imaging option. Ultrasound and MRI, due to lack of ionizing radiation, are preferred over CT and nuclear imaging. The latter may be considered only if the benefits of imaging outweigh maternal and fetal risk without exceeding the cumulative established fetal radiation dose threshold. This article provides an overview of all currently available imaging options that can be used for imaging cancer during pregnancy to support the best possible maternal and fetal outcomes.

Mimics of cancer in pregnancy.

Pregnancy is a remarkable time of pronounced growth and development of the fetus. Benign pathologies outside of the uterus, including those containing hormonally responsive tissue which undergo physiologic changes and other incidentally identified lesions, may mimic malignancy on clinical evaluation and imaging. A detailed history and physical exam, ultrasound and non-contrast magnetic resonance imaging features and comparison with prior imaging if available may help to narrow the list of potential differential diagnoses. Follow-up imaging in the postpartum period is often vital to confirm benignity and, in some cases, sampling to confirm the diagnosis is necessary. This review will cover the clinical, pathological and multimodality imaging features of numerous potential mimickers of cancer in the setting of pregnancy organized by organ systems. The goal is to better equip abdominal radiologists to accurately identify benign disease and help guide further imaging or follow-up recommendations to avoid unnecessarily aggressive intervention and improve patient care.

Radiology trainee and attending satisfaction with virtual readouts during the COVID-19 pandemic.

RATIONALE AND OBJECTIVES: In response to COVID-19, our institution implemented three virtual readout systems: a commercial HIPAA compliant web-based video conferencing platform used for screen-sharing (Starleaf), an interactive control sharing system integrated into PACS allowing simultaneous multi-user mouse control over images (Collaborate), and the telephone. Our aim was to assess overall satisfaction with and perceived effectiveness of these virtual readout methods to optimize best practices for the future. MATERIALS AND METHODS: An IRB-exempt survey was electronically distributed to 64 trainees and 76 attendings at one tertiary-care institution via Survey Monkey. Questions focused on overall satisfaction, perceived effectiveness, technical difficulties, and continued future use of the three virtual readout strategies. Answers were collected with Likert scales, tick boxes, and open-ended questions. RESULTS: 32/64 trainees (50%) and 32/76 attendings (42%) completed the survey. Trainees and attendings were more satisfied with screen sharing (Starleaf) and perceived it more effective than control sharing (Collaborate) or the telephone (p < 0.0001). Respondents experienced more technical difficulties with control sharing versus screen sharing (p = 0.0004) with a negative correlation between level of technical difficulties and satisfaction with screen sharing (r = -0.50, p < 0.0001) and control sharing (r = -0.38, p = 0.0006). Trainees and faculty supported a combination of in-person and virtual readouts in the future (p < 0.0001). CONCLUSION: Platforms mirroring in-person readouts, such as Starleaf, are preferred by both trainees and attendings over non-screen sharing platforms such as the telephone. However, technical stability determines satisfaction between similar platforms. Both trainees and attendings support incorporation of virtual readout methods in combination with traditional in-person readouts in the post-COVID-19 era.

Spectrum of MRI Features of Mucin-producing Neoplasms in the Abdomen and Pelvis.

Mucin-producing neoplasms in the abdomen and pelvis are a distinct entity, separate from simple fluid-containing neoplasms and loculated fluid collections. Mucin is a thick gelatinous substance and-owing to its high water content-has imaging features that can be mistaken for those of simple fluid-containing neoplasms with multiple imaging modalities. However, mucin-producing neoplasms arise from specific organs in the abdomen and pelvis, with unique imaging appearances, knowledge of which is important to guide accurate diagnosis and management. With its large field of view and high soft-tissue resolution, MRI has advantages over other imaging modalities in characterizing these neoplasms. The authors focus on the spectrum of MRI features of such mucin-producing neoplasms and illustrate how-despite a varied organ origin-some of these neoplasms share similar MRI and histopathologic features, thereby helping narrow the differential diagnosis. One common finding in these tumors is that the presence of internal complexity and solid enhancing components increases as the degree of malignant transformation increases. Lack of internal complexity generally indicates benignity. These tumors have a varied range of prognosis; for example, a low-grade appendiceal mucinous neoplasm is indicative of a good prognosis, while a mucinous tumor of the rectum is known to manifest at an early age with aggressive behavior and poorer prognosis compared with its nonmucinous counterpart. Online supplemental material is available for this article. ©RSNA, 2022.

Neoadjuvant Yttrium-90 Transarterial Radioembolization with Resin Microspheres Prescribed Using the Medical Internal Radiation Dose Model for Intrahepatic Cholangiocarcinoma.

PURPOSE: To evaluate outcomes of patients with intrahepatic cholangiocarcinoma (iCCA) undergoing neoadjuvant yttrium-90 (90Y) transarterial radioembolization (TARE) with resin microspheres prescribed using the Medical Internal Radiation Dose (MIRD) model. MATERIALS AND METHODS: This retrospective institutional review board-approved study included 37 patients with iCCA treated with 90Y-TARE from October 2015 to September 2020. The primary outcome was overall survival (OS) from 90Y-TARE. The secondary outcomes were progression-free survival (PFS), Response Evaluation Criteria In Solid Tumors 1.1 imaging response, and downstaging to resection. Patients with tumor proximity to the middle hepatic vein (<1 cm) and/or insufficient future liver remnant were treated with neoadjuvant intent (n = 21). Patients were censored at the time of surgery or at the last follow-up for the Kaplan-Meier survival analysis. RESULTS: For 31 patients (69 years; interquartile range, 64-74 years; 20 men [65%]) included in the study, the first-line therapy was 90Y-TARE for 23 (74%) patients. Imaging assessment at 6 months showed a disease control rate of 86%. The median PFS was 5.4 months (95% confidence interval [CI], 3-not reached). The PFS was higher after first-line 90Y-TARE (7.4 months [95% CI, 5.3-not reached]) than that after subsequent 90Y-TARE (2.7 months [95% CI, 2-not reached]) (P = .007). The median OS was 22 months (95% CI, 7.3-not reached). The 1- and 2-year OS rates were 60% (95% CI, 41%-86%) and 40% (95% CI, 19.5%-81%). In patients treated with neoadjuvant intent, 11 of 21 patients (52%) underwent resections. The resection margins were R0 and R1 in 8 (73%) and 3 (27%) of 11 patients, respectively. On histological review in 10 patients, necrosis of ≥90% tumor was achieved in 7 of 10 patients (70%). CONCLUSIONS: First-line 90Y-TARE prescribed using the MIRD model as neoadjuvant therapy for iCCA results in good survival outcome and R0 resection for unresectable patients.

LI-RADS treatment response lexicon: review, refresh and resolve with emerging data.

The imaging findings after loco regional treatment of hepatocellular carcinoma are variable based on the type of treatment used, the timing interval of imaging after treatment, and the cross-sectional modality used for treatment response assessment. Liver Imaging Reporting and Data System (LI-RADS) Treatment Response Algorithm (TRA) is a relatively new standardized method of evaluating treatment response after loco regional therapy to hepatocellular carcinoma. In this article, we provide an overview of the evolution of the treatment response algorithm, its current applicability and its outlook for the future. We will review current guidelines and discuss proposed changes to the algorithm as a means to continually improve LI-RADS TRA as an assessment tool post-loco regional treatment of hepatocellular carcinoma.

Role of the radiologist at HCC multidisciplinary conference and use of the LR-TR algorithm for improving workflow.

Multidisciplinary conferences (MDCs) play a major role in management and care of oncology patients. Hepatocellular carcinoma (HCC) is a complex disease benefiting from multidisciplinary discussions to determine optimal patient management. A multitude of liver-directed locoregional therapies have emerged allowing for more options for treatment of HCC. A radiologist dedicated to HCC-MDC is an important member of the team contributing to patient care in multiple ways. The radiologist plays a key role in image interpretation guiding initial therapy discussions as well as interpreting post-treatment imaging following liver-directed therapy. Standardization of image interpretation can lead to more consistent treatment received by the patient as well as accurate assessment of transplant eligibility. The radiologist can facilitate this process using structured reporting that is also supported by stakeholders involved in interdisciplinary management of liver diseases. The Liver Imaging Reporting and Data System (LI-RADS), is a living document which offers a standardized reporting algorithm for consistent communication of radiologic findings for HCC screening and characterization of liver observations in patients at risk for HCC. The LI-RADS post-treatment algorithm (LR-TR algorithm) has been developed to standardize liver observations following liver-directed locoregional therapy. This review article focuses on the role of the radiologist at HCC-MDC and implementation of the LR-TR algorithm for improving workflow.

Resident Experiences With Virtual Radiology Learning During the COVID-19 Pandemic.

RATIONALE AND OBJECTIVES: COVID-19 has disrupted radiology education and forced a transition from traditional in-person learning to a virtual platform. As a result of hospital and state mandates, our radiology residency program quickly transitioned to a virtual learning platform to continue dissemination of knowledge, maintain resident engagement, and ensure professional development. The goal of this study is to assess the strengths and weaknesses of the virtual learning platform at our institution using resident ratings. MATERIALS AND METHODS: This institutional IRB-exempt study involved a survey of 17 questions which was electronically distributed to 45 radiology residents using SurveyMonkey. Questions encompassed resident satisfaction with teaching and professional development, scheduling changes, and engagement with the virtual platform. Answers to most questions were submitted on a Likert scale. RESULTS: A total of 31 of 45 respondents completed the survey (response rate = 69%). Most residents were satisfied with the virtual platform with teaching activities identified as a strength and the incorporation of professional development as a weakness. The most frequent barriers to attending the virtual curriculum were technical difficulties (43%) and childcare (36%). Residents who reported experiencing barriers were less likely to adhere to the virtual curriculum (p = 0.004). Most respondents (81%) reported a desire to maintain elements of the virtual learning practice postpandemic. CONCLUSION: The majority of residents reported high satisfaction with virtual learning during the COVID-19 pandemic. Teaching activities are a curricular strength. Weaknesses identified include the incorporation of professional development and extrinsic barriers, such as technical difficulties and family obligations, which require further support for trainees.