Smooth Muscle Tumors of the Uterus at MRI: Focus on Leiomyomas and FIGO Classification.

Leiomyomas are smooth muscle tumors of the uterus and are the most common uterine neoplasm. Although leiomyomas are usually asymptomatic, they can manifest with symptoms such as pain or uterine bleeding. Leiomyomas are classified on the basis of their anatomic location and morphology. Localization of leiomyomas relative to the endometrium, myometrium, and uterine serosa with use of the International Federation of Gynecology and Obstetrics (FIGO) classification system is helpful for guiding management in symptomatic patients. The FIGO system is a practical and universally accepted approach for classifying leiomyomas to guide radiologists and clinicians in deciding management. The MRI appearance of conventional leiomyomas is related to their tissue contents of smooth muscle and fibrous tissue and is well established. The MRI features of some leiomyoma subtypes and forms of degeneration also have been described. Other smooth muscle tumors of the uterus recognized in the 2020 World Health Organization classification system include intravenous leiomyomatosis, smooth muscle tumors of uncertain malignant potential, and metastasizing leiomyoma. At the far end of the spectrum are leiomyosarcomas, which are frankly malignant and therefore must be managed accordingly. Although MRI features that suggest a diagnosis of leiomyosarcoma have been proposed, these features overlap with those of some leiomyoma subtypes and degeneration. © RSNA, 2023 See the invited commentary by Fennessy and Gargiulo in this issue. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Quiz questions for this article are available through the Online Learning Center.

Urinary Bladder Masses, Rare Subtypes, and Masslike Lesions: Radiologic-Pathologic Correlation.

Urinary bladder masses are commonly encountered in clinical practice, with 95% arising from the epithelial layer and rarer tumors arising from the lamina propria, muscularis propria, serosa, and adventitia. The extent of neoplastic invasion into these bladder layers is assessed with multimodality imaging, and the MRI-based Vesical Imaging Reporting and Data System is increasingly used to aid tumor staging. Given the multiple layers and cell lineages, a diverse array of pathologic entities can arise from the urinary bladder, and distinguishing among benign, malignant, and nonneoplastic entities is not reliably feasible in most cases. Pathologic assessment remains the standard of care for classification of bladder masses. Although urothelial carcinoma accounts for most urinary bladder malignancies in the United States, several histopathologic entities exist, including squamous cell carcinoma, adenocarcinoma, melanoma, and neuroendocrine tumors. Furthermore, there are variant histopathologic subtypes of urothelial carcinoma (eg, the plasmacytoid variant), which are often aggressive. Atypical benign bladder masses are diverse and can have inflammatory or iatrogenic causes and mimic malignancy. © RSNA, 2022 Online supplemental material is available for this article.

MRI Evaluation of Patients Before and After Interventions for Benign Prostatic Hyperplasia: An Update.

Transurethral resection of the prostate is the most commonly performed procedure for the management of patients with lower urinary tract symptoms attributed to benign prostatic hyperplasia (BPH). However, in recent years, various minimally invasive surgical therapies have been introduced to treat BPH. These include laser-based procedures such as holmium laser enucleation of the prostate and photoselective vaporization of the prostate as well as thermal ablation procedures such as water vapor thermal therapy (Rezum), all of which result in volume reduction of periurethral prostatic tissue. In comparison, a permanent metallic device (UroLift) can be implanted to pull open the prostatic urethra without an associated decrease in prostate size, and selective catheter-directed prostate artery embolization results in a global decrease in prostate size. The goal of this article is to familiarize radiologists with the underlying anatomic changes that occur in BPH as visualized on MRI and to describe the appearance of the prostate on MRI performed after these procedures. Complications encountered on imaging after these procedures are also discussed. Although MRI is not currently used in the routine preprocedural evaluation of BPH, emerging data support a role for MRI in predicting postprocedure outcomes.

Tumor Evolution in a Patient with Recurrent Endometrial Cancer and Synchronous Neuroendocrine Cancer and Response to Checkpoint Inhibitor Treatment.

Both metachronous and synchronous tumors pose a diagnostic and clinical challenge, more so when one of the specimens demonstrates the rare neuroendocrine histology. We describe a patient with sarcoidosis who was treated for endometrial and ovarian neoplasm, recurred with two separate histologies (adenocarcinoma and high grade neuroendocrine), both associated with microsatellite instability (MSI)-high status. Targeted next-generation sequencing of tumor with synonymous somatic alterations pointed to a common ancestry of all three tumors and patient was successfully treated with a tailored immunotherapy regimen. Her sarcoidosis worsened only slightly, and immunotherapy did not need to be discontinued. This case highlights the importance of molecular testing for the optimal therapy of complex synchronous tumors and the need for communication between surgical and medical oncologists in patients with MSI-high cancer. KEY POINTS: The case of a patient with a recurrent gynecological cancer presenting as microsatellite instability (MSI)-high endometrial adenocarcinoma and MSI-high neuroendocrine tumor is reported. This case demonstrated a common genetic lineage with good response to checkpoint inhibition without clinical worsening of autoimmune disease. This article adds to the literature, suggesting tumor evolution with neuroendocrine differentiation in some cancers, and argues that a molecular-based approach to treatment might achieve better understanding and possibly superior treatment outcomes.

Imaging of the Vagina: Spectrum of Disease with Emphasis on MRI Appearance.

The vagina is a median fibromuscular structure of the female reproductive system that extends from the vulva inferiorly to the uterine cervix superiorly. As most vaginal lesions are detected at gynecologic examination, imaging performed for nongynecologic indications can frequently cause concomitant vaginal pathologic conditions to be overlooked. The vagina is often underevaluated at routinely performed pelvic transvaginal US because of a narrow scan area and probe positioning. MRI has progressively become the imaging method of choice for vaginal pathologic conditions, as it provides excellent soft-tissue detail with unparalleled delineation of the complex pelvic floor anatomy and helps establish a diagnosis for most vaginal diseases. It is important that radiologists use a focused approach toward understanding and correctly recognizing different vaginal entities that may otherwise go unnoticed. In this case-based review, the authors discuss the key imaging features of wide-ranging vaginal pathologic conditions, with emphasis on appearance at MRI. Knowledge of vaginal anatomy and embryology is helpful in evaluating congenital anomalies at imaging. Often seen incidentally, vaginal inflammation can cause diagnostic confusion. Because of its central location in the pelvis, the vagina can form fistulas to the urinary bladder, colon, rectum, or anus. Vaginal masses can be neoplastic and nonneoplastic and include a myriad of benign and malignant conditions, some of which have characteristic imaging features. Therapeutic and nontherapeutic vaginal foreign bodies include pessaries, vaginal mesh, and packing that can be seen with or without associated complications. Online supplemental material is available for this article. ©RSNA, 2021.

Feasibility and safety of non-operative management of portal vein aneurysms: a thirty-five year experience.

BACKGROUND: Portal vein aneurysms (PVAs) are rare, though clinically challenging with post-operative mortality approaching 20% and no evidence-based treatment guidelines. We aim to describe our experience with PVAs and recommend optimum management strategies. METHODS: Demographics and clinical details of patients with PVAs admitted to our institution from 1984 to 2019 were reviewed. Clinical presentation, management and outcomes were analysed. RESULTS: PVAs were identified in 18 patients (median age 56 years, range 20-101 years; 13 female); 10 were incidental and 8 diagnosed during abdominal pain work-up. Median aneurysm diameter at diagnosis was 3.4 cm (1.8-5.5 cm), remaining unchanged at 3.5 cm (1.9-4.8 cm) during a 3.2-year follow-up (4 months-31 years). Aneurysm sites were the main portal vein (n = 12), porto-splenic-junction (n = 3), splenic-SMV-junction (n = 2) and right portal vein (n = 1). Thrombosis occurred in 4 patients; 3 developed clinically insignificant cavernous transformation. Two patients underwent surgery for abdominal pain. Postoperatively, one developed PV thrombosis and PVA recurrence occurred in the second. No aneurysm ruptures or mortalities occurred during follow-up. CONCLUSION: PVAs follow a clinically indolent course with structural stability and minimal complications over time. Non-operative management is feasible for most patients. Abdominal pain, large size or thrombosis don't appear to confer additional risks and should not, in isolation, merit surgical intervention.

Apparent Diffusion Coefficient Distinguishes Malignancy in T1-Hyperintense Small Renal Masses.

OBJECTIVE. Small renal masses (< 4 cm) can be difficult to accurately classify as benign or malignant, particularly when they appear T1 hyperintense on MRI. This intrinsic signal, potentially related to intralesional hemorrhage, may limit evaluation of signal intensity on DWI. The purpose of this study was to test whether apparent diffusion coefficient (ADC) measurements may distinguish malignancy. MATERIALS AND METHODS. This single-center retrospective study identified patients with a T1-hyperintense renal mass less than 4 cm on MRI. Malignant lesions were pathologically proven; a benign mass was established by a predefined hierarchy of pathologic proof, follow-up ultrasound, or follow-up imaging showing more than 5 years of stability. T1 hyperintensity, defined as a signal intensity equivalent to or greater than the adjacent renal cortex, was confirmed by a senior abdominal radiologist. Two additional abdominal radiologists independently measured ADC of the lesion, which was normalized to the ADC of the background ipsilateral kidney and represented as ADCratio. RESULTS. The final cohort included 58 benign and 37 malignant renal lesions in 95 patients. Interrater agreement for ADC measurements was almost perfect (κ = 0.836-0.934). ADCratio was significantly lower in malignant compared with benign lesions (0.65 ± 0.29 vs 1.03 ± 0.32; p < 0.001). Malignant lesions were significantly larger than benign lesions (2.66 ± 0.86 cm vs 1.50 ± 0.65 cm; p < 0.001); however, after controlling for lesion size, ADCratio remained a significant predictor of malignancy (p < 0.001). CONCLUSION. ADCratio was highly reproducible for T1-hyperintense small renal masses and was significantly lower in malignant compared with benign renal masses.

Computed Tomography Identifies Clinically Unsuspected Acute Necrotizing Pancreatitis Complicating Abdominal Aortic Repair.

BACKGROUND: Pancreatitis rarely complicates aortic repair. The aim of the study was to examine the role of imaging in identifying this complication and to characterize pancreatitis occuring in this setting. METHODS: The radiology information system queried reports for terms pancreatitis, fluid collection, peripancreatic fluid, and aortic/aneurysm/endovascular/open repair from January 2010 through May 2018 and yielded 243 unique patients. Aortic repair and pancreatitis did not occur in temporal proximity (within 30 days) in 227 patients, and three patients had invalid medical record numbers. The final population was 13 patients. Surgical data included indication for repair and surgical approach. Clinical/imaging data points included method of diagnosis, type of pancreatitis, location, management of collections, and patient outcome. RESULTS: Thirteen patients (n = 9 male, age 58-76 years) met inclusion criteria. All patients underwent open repair, 9 electively. Acute pancreatitis was first identified by computed tomography in 10 (77%) patients and by serum lipase levels in 3 patients (23%). Necrotizing pancreatitis was present in 10 patients (77%), eight with infected collections (one not sampled). Four patients (31%) had collections fistulizing to the aortic sac, and there was one case of aortic anastomotic pseudoaneurysm. There were 7 deaths (4 septic shock, 1 hemorrhagic pancreatitis, 1 pulmonary embolism, and 1 multiorgan failure) despite 5 of these patients undergoing drainage of collections. In surviving patients, 4 underwent drainage of collections, 1 necrosectomy, and 1 no intervention. CONCLUSIONS: Pancreatitis complicating aortic repair occurs after open repair and is often necrotizing. Pancreatitis is more often first detected by imaging rather than serum lipase levels. High mortality is more attributable to complications of pancreatitis rather than failure of the aortic repair.

A Color Flow Tract in Ultrasound-Guided Random Renal Core Biopsy Predicts Complications.

OBJECTIVES: To determine patient and procedural risk factors for major complications in ultrasound (US)-guided random renal core biopsy. METHODS: Random renal biopsies performed by radiologists in the US department at a single institution between 2014 and 2018 were retrospectively reviewed. The patient's age, sex, race, and estimated glomerular filtration rate (eGFR) were recorded. The biopsy approach, needle gauge, length of cores, number of throws, and presence of a color flow tract were recorded. Outcome data included minor and major complications. Associations between variables were tested with χ2 analyses and univariable/multivariable logistic regression models. RESULTS: A total of 231 biopsies (167 native and 64 allografts) were reviewed. There was no significant difference in the sex, age, race, or eGFR between native and allograft groups. The overall rate for any complication was 18.2%, with a 4.3% rate of major complications, which was significantly greater in native compared to allograft biopsies (6% versus 0%; P = .045). A risk analysis in native biopsies only showed that major complications were significantly associated with a low eGFR such that patients with stage 4 or 5 kidney disease had higher odds of complications (odds ratio [95% confidence interval]: stage 4, 9.405 [1.995-44.338]; P = .0393; stage 5, 10.749 [2.218-52.080]; P = .0203) than patients with normal function (eGFR >60 mL/min). The presence of a color flow tract portended a 10.7 times greater risk of having any complication (95% confidence interval, 4.595-24.994; P < .001). Other procedural factors were not significantly associated with complications. CONCLUSIONS: There is an increased risk of major complications in US-guided random native kidney biopsy in patients with a low eGFR (<30 mL/min) and a patent color flow tract in the immediate postbiopsy setting.

Formulating a Treatment Plan in Suspected Lymphoma: Ultrasound-Guided Core Needle Biopsy Versus Core Needle Biopsy and Fine-Needle Aspiration of Peripheral Lymph Nodes.

OBJECTIVES: Image-guided tissue sampling in the workup of suspected lymphoma can be performed by core needle biopsy (CNB) or CNB with fine-needle aspiration (FNA). We compared the yield of clinically actionable diagnoses between these methods of tissue sampling. METHODS: All ultrasound-guided percutaneous peripheral lymph node biopsies from 2010 to 2017 at a single institution were retrospectively reviewed for biopsy type (CNB versus CNB + FNA), prior diagnosis of lymphoma, size of the target lymph node, number of cores, length of core specimens, and pathologic diagnosis. Lymphoma and lymphoid tissue were included; metastatic disease and nonlymphoid tissue were excluded. An oncologist specializing in lymphoma independently determined whether an actionable diagnosis could be made with the pathologic results in the context of the patient's medical record. χ2 analyses and univariable/multivariable logistic regression models were used for statistical analyses. RESULTS: Of 578 lymph node biopsies, 306 (53%) had a prior diagnosis of lymphoma; 273 (47%) were CNB, and 305 (53%) were CNB + FNA. There was no significant difference between biopsy types (CNB versus CNB + FNA) in the number of cores (median [25th, 75th percentiles], 3 [3, 4] versus 4 [3, 4]; P = .47) or total length of tissue (4.1 [2.5, 6.1] versus 3.7 [2.3, 6] cm; P = .09). There was no difference in obtaining an actionable diagnosis between biopsy types after controlling for a known history of lymphoma (P = .271) or after controlling for the number of core specimens (P = .826). CONCLUSIONS: In cases of suspected lymphoma, CNB without FNA was sufficient to obtain an actionable diagnosis.

Assessment of disease aggression in cystic pancreatic neuroendocrine tumors: A CT and pathology correlation study.

BACKGROUND/OBJECTIVES: There are inconsistencies in the literature regarding the clinical significance of cystic components in pancreatic neuroendocrine tumors (NET). This may be related to differences in the identification of cystic NET through imaging and/or pathology. Tumors may also be microscopically or macroscopically cystic. Our primary objective is to determine radiology-pathology correlation for the identification of cystic components. Our secondary objective is to determine if cystic components are associated with indices of tumor aggression. METHODS: 60 tumors with correlative surgical pathology were assessed retrospectively for cystic components on CT and pathology. Tumor was categorized as solid or cystic on CT and pathology. If cystic on pathology, cystic components were categorized as macroscopic or microscopic. Cystic components were estimated as <50% and ≥50% tumor volume. WHO/Hochwald grade and presence of metastases were used to stratify disease aggression. Associations were tested with Chi square/Fisher's exact test and differences were tested with t-test/Wilcoxon rank sums test. RESULTS: There is moderate agreement between CT and histology for presence of cystic components. Discrepancies were mostly attributable to the presence of microscopic cystic components in tumors appearing solid on CT. There was no difference in size between cystic and solid tumors on CT or pathology. No association between CT-determined cystic components and tumor grade was found. Tumors with cystic components (cystic by CT, and macroscopically cystic by pathology) demonstrated less association with metastases than solid tumors. CONCLUSIONS: Cystic components, comprising ≥50% of the tumor by CT and observed macroscopically on pathology, are associated with less aggressive disease.

Targeting tumour-associated macrophages with CCR2 inhibition in combination with FOLFIRINOX in patients with borderline resectable and locally advanced pancreatic cancer: a single-centre, open-label, dose-finding, non-randomised, phase 1b trial.

BACKGROUND: In pancreatic ductal adenocarcinoma, the CCL2-CCR2 chemokine axis is used to recruit tumour-associated macrophages for construction of an immunosuppressive tumour microenvironment. This pathway has prognostic implications in pancreatic cancer, and blockade of CCR2 restores anti-tumour immunity in preclinical models. We aimed to establish the safety, tolerability, and recommended phase 2 oral dose of the CCR2 inhibitor PF-04136309 in combination with FOLFIRINOX chemotherapy (oxaliplatin and irinotecan plus leucovorin and fluorouracil). METHODS: We did this open-label, dose-finding, non-randomised, phase 1b study at one centre in the USA. We enrolled treatment-naive patients aged 18 years or older with borderline resectable or locally advanced biopsy-proven pancreatic ductal adenocarcinoma, an Eastern Cooperative Oncology Group performance status of 1 or less, measurable disease as defined by Response Evaluation Criteria in Solid Tumors version 1.1, and normal end-organ function. Patients were allocated to receive either FOLFIRINOX alone (oxaliplatin 85 mg/m(2), irinotecan 180 mg/m(2), leucovorin 400 mg/m(2), and bolus fluorouracil 400 mg/m(2), followed by 2400 mg/m(2) 46-h continuous infusion), administered every 2 weeks for a total of six treatment cycles, or in combination with oral PF-04136309, administered at a starting dose of 500 mg twice daily in a standard 3 + 3 dose de-escalation design. Both FOLFIRINOX and PF-04136309 were simultaneously initiated with a total treatment duration of 12 weeks. The primary endpoints were the safety, tolerability, and recommended phase 2 dose of PF-04136309 plus FOLFIRINOX, with an expansion phase planned at the recommended dose. We analysed the primary outcome by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01413022. RESULTS: Between April 19, 2012, and Nov 12, 2014, we treated 47 patients with FOLFIRINOX alone (n=8) or with FOLFIRINOX plus PF-04136309 (n=39). One patient had a dose-limiting toxic effect in the dose de-escalation group receiving FOLFIRINOX plus PF-04136309 at 500 mg twice daily (n=6); this dose was established as the recommended phase 2 dose. We pooled patients in the expansion-phase group (n=33) with those in the dose de-escalation group that received PF-04136309 at the recommended phase 2 dose for assessment of treatment-related toxicity. Six (75%) of the eight patients receiving FOLFIRINOX alone were assessed for treatment toxicity, after exclusion of two (25%) patients due to insurance coverage issues. The median duration of follow-up for treatment toxicity was 72·0 days (IQR 49·5-89·0) in the FOLFIRINOX alone group and 77·0 days (70·0-90·5) in the FOLFIRINOX plus PF-04136309 group. No treatment-related deaths occurred. Two (5%) patients in the FOLFIRINOX plus PF-04136309 group stopped treatment earlier than planned due to treatment-related toxic effects. Grade 3 or higher adverse events reported in at least 10% of the patients receiving PF-04136309 included neutropenia (n=27), febrile neutropenia (n=7), lymphopenia (n=4), diarrhoea (n=6), and hypokalaemia (n=7). Grade 3 or higher adverse events reported in at least 10% of patients receiving FOLFIRINOX alone were neutropenia (n=6), febrile neutropenia (n=1), anaemia (n=2), lymphopenia (n=1), diarrhoea (n=2), hypoalbuminaemia (n=1), and hypokalaemia (n=3). Therapy was terminated because of treatment-related toxicity in one (17%) of the six patients receiving FOLFIRINOX alone. 16 (49%) of 33 patients receiving FOLFIRINOX plus PF-04136309 who had undergone repeat imaging achieved an objective tumour response, with local tumour control achieved in 32 (97%) patients. In the FOLFIRINOX alone group, none of the five patients with repeat imaging achieved an objective response, although four (80%) of those patients achieved stable disease. INTERPRETATION: CCR2-targeted therapy with PF-04136309 in combination with FOLFIRINOX is safe and tolerable. FUNDING: Washington University-Pfizer Biomedical Collaborative.

Hot spleen: hypervascular lesions of the spleen.

The differential diagnosis of splenic masses is broad and often hinges on the enhancement characteristics of the lesions. Most radiologists are familiar with the differential diagnosis of hypovascular lesions such as fungal infections, sarcoidosis/granulomatous disease, infarctions, and cysts. However, to our knowledge, there is no review article that presents the specific multimodality imaging features of vascular splenic lesions as a group. Vascular splenic lesions may be considered those that enhance more or similarly to the background splenic parenchyma. In this review, we illustrate the spectrum of imaging features of both benign and malignant vascular splenic lesions. The benign lesions include hemangiomas, hamartomas, and sclerosing angiomatoid nodular transformation of the spleen. The malignant lesions are divided into primary and metastatic lesions, ranging from lymphoma, angiosarcoma to pleomorphic sarcoma. While lymphoma and metastases may commonly present as hypoenhancing lesions relative to the background parenchyma, we are addressing them here as their appearance can be varied and hence deserve consideration. Littoral Cell angiomas are discussed separately, as they were originally considered benign, but recent studies have shown that they can have malignant potential.

MRI of the stomach: a pictorial review with a focus on oncological applications and gastric motility.

The purpose of this pictorial review is to demonstrate gastric pathology seen on magnetic resonance imaging (MRI) and discuss the essential MRI sequences for the evaluation of benign and malignant gastric pathologies. Common tumors of the stomach, polyposis syndromes, iatrogenic conditions, as well as other conditions of the stomach will be reviewed. The utility of MRI in the evaluation of patients with gastric malignancies and disorders of gastric motility will also be discussed.

Magnetic resonance imaging of iatrogeny: understanding imaging artifacts related to medical devices.

Medical devices are frequently encountered in patients presenting for imaging studies. Knowledge of the device composition, dwell time, and location is essential for determining the safety and potential impact on the quality of magnetic resonance imaging (MRI) examinations. Anticipation of MRI artifacts associated with implanted devices allows the radiologist to adjust parameters to mitigate their effect on the anatomy of interest and to avoid pitfalls in interpretation. The purpose of this article is to present a pictorial review of the MRI appearance of commonly encountered implanted devices and foreign objects in order to help the radiologist anticipate their impact on final image quality.

Effects of Patient Demographics and Examination Factors on Patient Experience in Outpatient MRI Appointments.

OBJECTIVE: The objective of this article is to describe the effects of patient demographics and examination factors on patient-reported experience in outpatient MRI examinations. METHODS: This institutional review board-waived, HIPPA-compliant quality improvement study evaluated outpatient MRI appointments from March 2021 to January 2022 using a postappointment survey consisting of a 5-point emoji scale and text-based feedback. Patient demographics and examination information were extracted from electronic medical records. Ratings ≤ 3 were categorized as negative, and ratings ≥ 4 were categorized as positive. Continuous variables were analyzed using the Kruskal-Wallis test, and categorical variables were analyzed using the Fisher's exact test. A P value less than .05 was considered significant. A natural language processing algorithm was trained and validated to categorize patient feedback. RESULTS: A total of 3,636 patients responded to the survey. Positive ratings had a higher proportion of male respondents compared with negative ratings (47.9% versus 37.0%, P = .004). Examination characteristics were also grouped by positive or negative rating. Patients who endured longer examination time (median 54.0 min versus 44.0 min, P < .001) and longer wait time after check-in (median 61.6 min versus 46.2 min, P < .001) were more likely to give negative ratings. The most common themes of free text feedback included excellent service (84.3%), on-time service (8.4%), and comfortable intravenous line placement (0.4%). Most common negative feedback included long wait times (10.5%), poor communication (8.4%), and physical discomfort during the examination (4.2%). CONCLUSION: Male gender, short examination duration, and on-time start were associated with positive patient ratings.