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.

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.

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.

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.

Running a Radiology Residency Program: Strategies for Success.

Running a successful radiology residency program requires departments to navigate the evolving educational landscape at the departmental, institutional, and national levels. To attract the best applicants, departments must invest time and money to support the leadership of the program and its faculty to provide innovative educational opportunities in a positive learning environment while simultaneously complying with all of the requirements of the Accreditation Council for Graduate Medical Education. The key administrative requirements of a successful radiology residency program are described and can be grouped into (a) essential administrative components, (b) the clinical learning environment review and self-study process, and (c) resident recruitment. Ten specific strategies for running a successful residency program are also presented. The goal is for this article to serve as a guide for not only existing diagnostic and interventional radiology residency programs but also newly formed programs that are in the process of seeking accreditation. ©RSNA, 2018.

MRI of Placenta Accreta, Placenta Increta, and Placenta Percreta: Pearls and Pitfalls.

OBJECTIVE: The purpose of this article is to provide a primer for radiologists performing MRI for suspected placenta accreta, illustrating normal and abnormal findings and diagnostic pitfalls. Appropriate examination indications and recommendations for optimizing image acquisition and interpretation are summarized. CONCLUSION: MRI increases the accuracy of the workup of high-risk patients and aids in multidisciplinary delivery planning to improve maternal outcome. Reader accuracy and confidence require adherence to examination performance, image interpretation criteria, and awareness of common pitfalls.

Value of diffusion-weighted imaging when added to magnetic resonance enterographic evaluation of Crohn disease in children.

BACKGROUND: MR enterography is increasingly utilized for noninvasive evaluation of disease activity in young patients with Crohn disease and has great impact on clinical management. Diffusion-weighted imaging (DWI) is a rapid MR imaging technique that measures molecular diffusion of water and is sensitive to the inflammatory process; however, its value to MR enterography has not been rigorously evaluated. OBJECTIVE: To determine whether the addition of DWI to MR enterography is helpful in evaluating Crohn disease activity in young patients when compared to a histological reference. MATERIALS AND METHODS: In this single-institution retrospective study, we searched an imaging database for the period January 2010 to December 2012 to identify patients age 19 years and younger who had MR enterography with diffusion-weighted imaging (DWI). We used an electronic medical record search to identify those who had MR enterography and colonoscopy performed within 28 days of each other. All MR enterography scans were performed on a 1.5-T or 3-T clinical MR scanner with phased-array torso coil configuration using standard pulse sequences as well as axial DWI with b values of 50, 400 and 800. Bowel segments were evaluated for disease activity based on standard MR enterography sequences; in addition, segmental apparent diffusion coefficient (ADC) values were calculated based on DWI. Histological reference for disease activity was based on assessment for mucosal inflammatory changes on endoscopic biopsy. MR enterography and DWI evaluation were performed in a blinded fashion with respect to histological results. RESULTS: We included imaging of 78 bowel segments from 27 patients (mean age 14.5 ± 3.02 years) with known Crohn disease in the study. The mean ADC for bowel segments with active disease was 1.56 ± 0.7 × 10(3) mm(2)/s compared with 2.58 ± 1.4 × 10(3) mm(2)/s for segments without active disease, a difference that was statistically significant (P < 0.01, Student's t-test). Using a threshold value of 2.0 × 10(3) mm(2)/s, DWI demonstrated lower accuracy (64.1%) but higher sensitivity (78.8%) for detecting active disease compared with standard MR enterography (69.2% and 54.6%, respectively). Combining DWI with MR enterography, using DWI as the initial screen and MR enterography afterward to reduce false negativity, led to a significant increase in accuracy (76.9%; P = 0.03, McNemar's test) compared with either imaging technique alone. CONCLUSION: Although DWI does not perform as well as standard MR enterography for detection of active Crohn disease, the combination of DWI and MR enterography increases imaging accuracy for determining disease activity compared with either technique alone. These results indicate that DWI adds value to MR enterography and supports the incorporation of DWI into MR enterography protocols for evaluation of Crohn disease in young patients.

Feasibility and effectiveness of image-guided percutaneous biopsy of the urinary bladder.

PURPOSE: To evaluate the indications, technique, results, and complications of image-guided percutaneous biopsy of the urinary bladder. METHODS: This retrospective study included 15 patients (10 male, 5 female) who underwent image-guided percutaneous biopsy of the urinary bladder between January 1999 and December 2013. The medical records, imaging studies, procedural details, and long-term follow-up of each patient were reviewed in detail to assess the feasibility of percutaneous bladder biopsy. RESULTS: Ten patients had focal bladder masses and 5 patients had asymmetric or diffuse bladder wall thickening. Eleven patients had either negative or unsatisfactory cystoscopies prior to the biopsy. Percutaneous biopsies were performed under computed tomography guidance in 12 patients and ultrasound in 3 patients. All procedures were technically successful and there were no procedural complications. Malignancy was confirmed in 8 patients, among whom 6 had transitional cell carcinoma, 1 cervical cancer, and 1 prostate cancer metastasis. Seven patients had a benign diagnosis, including 3 that were later confirmed by pathology following surgery and 2 patients with a false-negative result. The overall sensitivity was 80% and accuracy was 87%. CONCLUSIONS: Image-guided percutaneous biopsy of the urinary bladder is a safe and technically feasible procedure with a high sensitivity and accuracy rate. Although image-guided bladder biopsy is an uncommon procedure, it should be considered in selected cases when more traditional methods of tissue sampling are either not possible or fail to identify abnormalities detected by cross-sectional imaging.

Preliminary results: prospective clinical study to assess image-based iterative reconstruction for abdominal computed tomography acquired at 2 radiation dose levels.

OBJECTIVE: The objective of this study was to compare image quality for abdominal computed tomographic (CT) images acquired at 200 and 50 mA s and reconstructed with image-based iterative reconstruction. MATERIALS AND METHODS: In this institutional review board-approved prospective study, 22 patients (mean [SD] age, 64.3 [14.4] years; male-female ratio, 12:10) gave informed consent for acquisition of additional abdominal CT images on 64-slice multi-detector CT (MDCT) (Siemens Definition Flash). Standard-dose images were acquired at 200 quality reference mA s, whereas low-dose images were acquired at 50 mA s (all series: 120 kV; 5-mm section thickness; pitch, 0.9:1). The low-dose images were reconstructed with a nonlinear 3-dimensional iterative image reconstruction (3D-IIR) (SafeCT; MedicVision, Tirat Carmel, Israel) (4 settings, namely, A1, A2, A3, and A4) and were assessed by 3 abdominal radiologists for lesion detection, image noise, and visibility of small structures. CATPHAN 500 was scanned at the respective doses to obtain noise spectral density and modulation transfer function. RESULTS: Subjective image noise was unacceptable at 50-mA s filtered back projection and improved to average in 50-mA s A1 and minimal or no noise in 50-mA s A4. However, the visibility of small structures was similar to standard-dose filtered back projection images on 50-mA s A2. Objective image noise was reduced to 66% for the 50-mA s 3D-IIR images (9.08 [2.3]/26.75 [6.8]). The modulation transfer function curve demonstrated resolution improvement in the low-dose images with the 3D-IIR technique, whereas the noise spectral density curve confirmed noise suppression in the 50-mA s 3D-IIR images. CONCLUSIONS: Three-dimensional iterative image reconstruction helps to lower image noise without affecting the visibility of small structures at "moderate" settings. Diagnostically acceptable abdominal CT examinations can be acquired at 75% lower-radiation dose with the help of the image-based iterative reconstruction technique.

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.

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.

Percutaneous biopsy of focal lesions of the gastrointestinal tract.

PURPOSE: To evaluate the technical success and diagnostic accuracy of image-guided percutaneous biopsy of the gastrointestinal (GI) tract. MATERIALS AND METHODS: An interventional radiology database was used to retrospectively identify patients who underwent image-guided percutaneous biopsy of the GI tract. The medical and imaging records were reviewed to assess biopsy results and complications. RESULTS: Twenty-nine patients (M:F = 19:10, mean age 65 years) were identified who underwent image-guided (CT/US) percutaneous biopsies of the GI tract. All biopsies were performed using coaxial technique with 18 g core and 22 g FNA needles. Twenty-two biopsies (76 %) were for circumferential or segmental wall thickening; the remaining were wall thickening with exophytic mass. Mean tumor diameter was 7.4 cm (SD = 3.4 cm), average wall thickening was 2.1 cm (SD 7.2), and exophytic mass was 10.0 cm (SD = 4.2). Tumor locations included stomach (n = 5), small bowel (n = 8), and colon (n = 16). Malignancy was confirmed in 22 patients, 12 of whom underwent excision, with 3 false positive samples. Benign disease was diagnosed in 7 patients, including 3 with pathology confirmation, with one false negative sample. The overall sensitivity was 83 % and accuracy was 84 %. There was one complication presenting as bleeding at the biopsy site, treated conservatively. CONCLUSION: Percutaneous biopsy of the GI tract is an uncommon procedure. The results of this study suggest that it is a safe and sensitive procedure that may be considered for small bowel lesions in which endoscopy is not feasible, for submucosal lesions, or in the setting of patients with previously negative endoscopic biopsies.

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.

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.