Four-Dimensional Computed Tomography for Parathyroid Adenoma Localization: A Pre-Operative Imaging Protocol.

OBJECTIVE: Primary hyperparathyroidism (PHPT) affects approximately 0.86% of the population, with surgical resection as the treatment of choice. A 4D computed tomography (CT) is a highly effective tool in localizing parathyroid adenomas; however, there is currently no defined role for 4D CT when stratified against ultrasonography (USG) and nuclear medicine Technetium Sestamibi SPECT/CT (SES) imaging. STUDY DESIGN: Retrospective Study. SETTING: University Hospital. METHODS: All patients who underwent parathyroidectomy for PHPT between 2014 and 2019 at a single institution were reviewed. Patients who had a 4D CT were included. We compared outcomes of 4D CT as a second line imaging modality to those of USG and SES as first line modalities. An imaging algorithm was proposed based on these findings. RESULTS: There were 84 patients identified who had a 4D CT after unsuccessful first line imaging. A 4D CT localized parathyroid adenoma to the correct quadrant in 64% of cases, and to the correct laterality in 75% of cases. Obese patients had significantly lower rates of adenoma localization with USG (33.4%), compared to non-obese patients (67.5%; P = .006). In determining multigland disease the sensitivity of 4D CT was 86%, while the specificity was 87%. CONCLUSIONS: A 4D CT has impressive rates of accurate localization of parathyroid adenomas; however due to the radiation exposure involved, it should remain a second line imaging modality. PHPT patients should first be evaluated with USG, with 4D CT used if this is unsuccessful and patients are greater than 40 years old, have a high BMI, or are having revision surgery.

The Natural History of Observed SDHx -Related Head and Neck Paragangliomas Using Three-Dimensional Volumetric Tumor Analysis.

OBJECTIVE: Characterize the natural history and clinical behavior of head and neck paragangliomas (HNPGLs) in subjects with succinate dehydrogenase ( SDHx ) pathogenic variants using volumetric tumor measurements. STUDY DESIGN: Cohort study. SETTING: Tertiary academic referral center. PATIENTS: Subjects with SDHx HNPGLs under observation for at least 6 months with 2 or more magnetic resonance imaging or computed tomography scans. INTERVENTIONS: Diagnostic interventions include next-generation sequencing, magnetic resonance imaging, and computed tomography. Therapeutic interventions include microsurgical resection or stereotactic radiosurgery. MAIN OUTCOME MEASURES: Radiographic progression was defined as a 20% or greater increase in volume. Cranial nerve (CN) functional outcomes were assessed using clinical documentation. RESULTS: A total of 19 subjects with 32 tumors met the inclusion criteria. Median radiographic follow-up was 2.2 years, and the median volumetric growth rate was 0.47 cm 3 /yr. Kaplan-Meier estimated rates of survival free of radiographic progression for all SDHx tumors at 1, 2, and 3 years were 69, 50, and 22%, respectively. No tumors developed new CN palsies during the period of observation. CONCLUSIONS: Over intermediate-term follow-up, observation of treatment-naive SDHx -related HNPGLs did not result in new cranial neuropathy. Although indefinite observation is only appropriate for select cases, these data support an interval of observation to characterize growth rate in asymptomatic to minimally symptomatic patients, who are at high risk of treatment-related morbidity. Given the early age at diagnosis and high risk of bilateral multifocal phenotypes in SDHx HNPGL mutation carriers, these data may aid in optimizing patient tumor control and CN functional preservation. Further studies are necessary to determine whether pretreatment growth rate is correlated with clinical outcomes.

PET-CT in Clinical Adult Oncology: I. Hematologic Malignancies.

PET-CT is an advanced imaging modality with many oncologic applications, including staging, assessment of response to therapy, restaging and evaluation of suspected recurrence. The goal of this 6-part series of review articles is to provide practical information to providers and imaging professionals regarding the best use of PET-CT for the more common adult malignancies. In the first article of this series, hematologic malignancies are addressed. The classification of these malignancies will be outlined, with the disclaimer that the classification of lymphomas is constantly evolving. Critical applications, potential pitfalls, and nuances of PET-CT imaging in hematologic malignancies and imaging features of the major categories of these tumors are addressed. Issues of clinical importance that must be reported by the imaging professionals are outlined. The focus of this article is on [18F] fluorodeoxyglucose (FDG), rather that research tracers or those requiring a local cyclotron. This information will serve as a resource for the appropriate role and limitations of PET-CT in the clinical management of patients with hematological malignancy for health care professionals caring for adult patients with hematologic malignancies. It also serves as a practical guide for imaging providers, including radiologists, nuclear medicine physicians and their trainees.

PET-CT in Clinical Adult Oncology: III. Gastrointestinal Malignancies.

PET-CT is an advanced imaging modality with many oncologic applications, including staging, assessment of response to therapy, restaging and longitudinal surveillance for recurrence. The goal of this series of six review articles is to provide practical information to providers and imaging professionals regarding the best use of PET-CT for specific oncologic indications, and the potential pitfalls and nuances that characterize these applications. In the third of these review articles, key tumor-specific clinical information and representative PET-CT images are provided to outline the role that PET-CT plays in the management of patients with gastrointestinal malignancies. The focus is on the use of 18F fluorodeoxyglucose (FDG), rather than on research radiopharmaceuticals under development. Many different types of gastrointestinal tumors exist, both pediatric and adult. A discussion of the role of FDG PET-CT for all of these is beyond the scope of this review. Rather, this article focuses on the most common adult gastrointestinal malignancies that may be encountered in clinical practice. The information provided here will provide information outlining the appropriate role of PET-CT in the clinical management of patients with gastrointestinal malignancies for healthcare professionals caring for adult cancer patients. It also addresses the nuances and provides interpretive guidance related to PET-CT for imaging providers, including radiologists, nuclear medicine physicians and their trainees.

PET-CT in Clinical Adult Oncology: II. Primary Thoracic and Breast Malignancies.

Positron emission tomography combined with x-ray computed tomography (PET-CT) is an advanced imaging modality with oncologic applications that include staging, therapy assessment, restaging, and surveillance. This six-part series of review articles provides practical information to providers and imaging professionals regarding the best use of PET-CT for the more common adult malignancies. The second article of this series addresses primary thoracic malignancy and breast cancer. For primary thoracic malignancy, the focus will be on lung cancer, malignant pleural mesothelioma, thymoma, and thymic carcinoma, with an emphasis on the use of FDG PET-CT. For breast cancer, the various histologic subtypes will be addressed, and will include 18F fluorodeoxyglucose (FDG), recently Food and Drug Administration (FDA)-approved 18F-fluoroestradiol (FES), and 18F sodium fluoride (NaF). The pitfalls and nuances of PET-CT in breast and primary thoracic malignancies and the imaging features that distinguish between subcategories of these tumors are addressed. This review will serve as a resource for the appropriate roles and limitations of PET-CT in the clinical management of patients with breast and primary thoracic malignancies for healthcare professionals caring for adult patients with these cancers. It also serves as a practical guide for imaging providers, including radiologists, nuclear medicine physicians, and their trainees.

PET-CT in Clinical Adult Oncology-V. Head and Neck and Neuro Oncology.

PET-CT is an advanced imaging modality with many oncologic applications, including staging, assessment of response to therapy, restaging, and longitudinal surveillance for recurrence. The goal of this series of six review articles is to provide practical information to providers and imaging professionals regarding the best use of PET-CT for specific oncologic indications, and the potential pitfalls and nuances that characterize these applications. In addition, key tumor-specific clinical information and representative PET-CT images are provided to outline the role that PET-CT plays in the management of oncology patients. Hundreds of different types of tumors exist, both pediatric and adult. A discussion of the role of FDG PET for all of these is beyond the scope of this review. Rather, this series of articles focuses on the most common adult malignancies that may be encountered in clinical practice. It also focuses on FDA-approved and clinically available radiopharmaceuticals, rather than research tracers or those requiring a local cyclotron. The fifth review article in this series focuses on PET-CT imaging in head and neck tumors, as well as brain tumors. Common normal variants, key anatomic features, and benign mimics of these tumors are reviewed. The goal of this review article is to provide the imaging professional with guidance in the interpretation of PET-CT for the more common head and neck malignancies and neuro oncology, and to inform the referring providers so that they can have realistic expectations of the value and limitations of PET-CT for the specific type of tumor being addressed.

PET-CT in Clinical Adult Oncology-VI. Primary Cutaneous Cancer, Sarcomas and Neuroendocrine Tumors.

PET-CT is an advanced imaging modality with many oncologic applications, including staging, therapeutic assessment, restaging and surveillance for recurrence. The goal of this series of six review articles is to provide practical information to providers and imaging professionals regarding the best use of PET-CT for specific oncologic indications, the potential pitfalls and nuances that characterize these applications, and guidelines for image interpretation. Tumor-specific clinical information and representative PET-CT images are provided. The current, sixth article in this series addresses PET-CT in an evaluation of aggressive cutaneous malignancies, sarcomas and neuroendocrine tumors. A discussion of the role of FDG PET for all types of tumors in these categories is beyond the scope of this review. Rather, this article focuses on the most common malignancies in adult patients encountered in clinical practice. It also focuses on Food and Drug Agency (FDA)-approved and clinically available radiopharmaceuticals rather than research tracers or those requiring a local cyclotron. This information will serve as a guide to primary providers for the appropriate role of PET-CT in managing patients with cutaneous malignancies, sarcomas and neuroendocrine tumors. The nuances of PET-CT interpretation as a practical guide for imaging providers, including radiologists, nuclear medicine physicians and their trainees, are also addressed.

PET-CT in Clinical Adult Oncology-IV. Gynecologic and Genitourinary Malignancies.

Concurrently acquired positron emission tomography and computed tomography (PET-CT) is an advanced imaging modality with diverse oncologic applications, including staging, therapeutic assessment, restaging and longitudinal surveillance. This series of six review articles focuses on providing practical information to providers and imaging professionals regarding the best use and interpretative strategies of PET-CT for oncologic indications in adult patients. In this fourth article of the series, the more common gynecological and adult genitourinary malignancies encountered in clinical practice are addressed, with an emphasis on Food and Drug Administration (FDA)-approved and clinically available radiopharmaceuticals. The advent of new FDA-approved radiopharmaceuticals for prostate cancer imaging has revolutionized PET-CT imaging in this important disease, and these are addressed in this report. However, [18F]F-fluoro-2-deoxy-d-glucose (FDG) remains the mainstay for PET-CT imaging of gynecologic and many other genitourinary malignancies. This information will serve as a guide for the appropriate role of PET-CT in the clinical management of gynecologic and genitourinary cancer patients for health care professionals caring for adult cancer patients. It also addresses the nuances and provides guidance in the accurate interpretation of FDG PET-CT in gynecological and genitourinary malignancies for imaging providers, including radiologists, nuclear medicine physicians and their trainees.

Interrater Reliability of NI-RADS on Posttreatment PET/Contrast-enhanced CT Scans in Head and Neck Squamous Cell Carcinoma.

Purpose To evaluate the interrater reliability among radiologists examining posttreatment head and neck squamous cell carcinoma (HNSCC) fluorodeoxyglucose PET/contrast-enhanced CT (CECT) scans using Neck Imaging Reporting and Data System (NI-RADS). Materials and Methods In this retrospective study, images in 80 patients with HNSCC who underwent posttreatment surveillance PET/CECT and immediate prior comparison CECT or PET/CECT (from June 2014 to July 2016) were uploaded to the American College of Radiology's cloud-based website, Cortex. Eight radiologists from seven institutions with variable NI-RADS experience independently evaluated each case and assigned an appropriate prose description and NI-RADS category for the primary site and the neck site. Five of these individuals were experienced readers (> 5 years of experience), and three were novices (< 5 years of experience). In total, 640 lexicon-based and NI-RADS categories were assigned to lesions among the 80 included patients by the eight radiologists. Light generalization of Cohen κ for interrater reliability was performed. Results Of the 80 included patients (mean age, 63 years ± 10 [standard deviation]), there were 58 men (73%); 60 patients had stage IV HNSCC (75%), and the most common tumor location was oropharynx (n = 32; 40%). Light κ for lexicon was 0.30 (95% CI: 0.23, 0.36) at the primary site and 0.31 (95% CI: 0.24, 0.37) at the neck site. Light κ for NI-RADS category was 0.55 (95% CI: 0.46, 0.63) at the primary site and 0.60 (95% CI: 0.48, 0.69) at the neck site. Percent agreement between lexicon and correlative NI-RADS category was 84.4% (540 of 640) at the primary site and 92.6% (593 of 640) at the neck site. There was no significant difference in interobserver agreement among the experienced versus novice raters. Conclusion Moderate agreement was achieved among eight radiologists using NI-RADS at posttreatment HNSCC surveillance imaging. Keywords: CT, PET/CT, Head/Neck, Neck, Neoplasms-Primary, Observer Performance Supplemental material is available for this article. © RSNA, 2021.

FDG-PET Imaging of Salivary Gland Tumors.

The salivary glands are host to a variety of benign and malignant tumors, as well as tumor-like conditions. Due to the variable FDG avidity of these lesions on positron emission tomography (PET) imaging, as well as the complex embryology and physiology that affect normal FDG uptake, FDG PET imaging of salivary gland pathology can prove challenging for head and neck imagers. We provide a practical guide for PET imaging of salivary gland tumors, detailing important additional diagnostic considerations, such as perineural tumor spread and intraparotid nodal metastases that are unique subsets related to salivary gland malignancy.

ACR Neck Imaging Reporting and Data Systems (NI-RADS): A White Paper of the ACR NI-RADS Committee.

Imaging surveillance after treatment for head and neck cancer is challenging because of complicated resection and reconstruction surgery, in addition to posttreatment changes from radiation and chemotherapy. The posttreatment neck is often a source of anxiety for diagnostic radiologists, leading to suboptimal reporting and no standardized guidance for next management steps. Nevertheless, imaging is critical for detecting submucosal recurrences in a timely manner, so that patients remain candidates for salvage surgery. In 2016, the ACR convened the Neck Imaging Reporting and Data Systems (NI-RADS) Committee with the goals to (1) provide recommendations for surveillance imaging; (2) produce a lexicon to distinguish between benign posttreatment change and residual or recurrent tumor in the posttreatment neck; and (3) propose a NI-RADS template for reporting on the basis of this lexicon with defined levels of suspicion and management recommendations. In this article, the authors present the ACR NI-RADS Committee's recommendations, which provide guidance regarding the management of patients after treatment for head and neck cancer.

Application of 3-Dimensional Printing in a Case of Osteogenesis Imperfecta for Patient Education, Anatomic Understanding, Preoperative Planning, and Intraoperative Evaluation.

BACKGROUND: The techniques and applications of 3-dimensional (3D) printing have progressed at a fast pace. In the last 10 years, there has been significant progress in applying this technology to medical applications. We present a case of osteogenesis imperfecta in which treatment was aided by prospectively using patient-specific, anatomically accurate 3D prints of the calvaria. The patient-specific, anatomically accurate 3D prints were used in the clinic and in the operating room to augment patient education, improve surgical decision making, and enhance preoperative planning. CASE DESCRIPTION: A 41-year-old woman with osteogenesis imperfecta and an extensive neurosurgical history presented for cranioplasty revision. Computed tomography (CT) data obtained as part of routine preoperative imaging were processed into a 3D model. The 3D patient-specific models were used in the clinic for patient education and in the operating room for preoperative visualization, planning, and intraoperative evaluation of anatomy. The patient reported the 3D models improved her understanding and comfort with the planned surgery when compared with discussing the procedure with the neurosurgeon or viewing the CT images with a neuroradiologist. The neurosurgeon reported an improved understanding of the patient's anatomy and potential cause of patient symptoms as well as improved preoperative planning compared with viewing the CT imaging alone. The neurosurgeon also reported an improvement in the planned surgical approach with a better intraoperative visualization and confirmation of the regions of planned calvarial resection. CONCLUSIONS: The use of patient-specific, anatomically accurate 3D prints may improve patient education, surgeon understanding and visualization, preoperative decision making, and intraoperative management.

Do Superior or Inferior Interlaminar Approach or Bevel Orientation Predispose to Nonepidural Needle Penetration?

OBJECTIVE: There is a paucity of evidence-based literature regarding the advantages and disadvantages of the interlaminar approach and needle bevel orientation for performing a lumbar interlaminar epidural steroid injection (ESI). The purpose of this study was to determine if superior versus inferior lamina approach, needle bevel tip orientation, or both may predispose to inadvertent nonepidural penetration during lumbar interlaminar ESI. SUBJECTS AND METHODS: A prospective study was performed of patients with low back pain with or without radicular pain or neurogenic claudication referred for lumbar interlaminar ESI. Two hundred eleven patients were randomized by interlaminar approach (superior vs inferior) and bevel tip orientation (cranial vs caudal). Lumbar interlaminar ESI was performed by six interventionalists of varying levels of experience using fluoroscopic guidance with curved tip epidural needles, using loss-of-resistance technique and confirmation with contrast opacification. Exact Poisson regression was used to model the study outcome. RESULTS: Two hundred twenty-one lumbar interlaminar ESIs were performed on 211 patients, randomized to a superior (n = 121) or inferior lamina approach (n = 100) and to a cranial (n = 103) or caudal (n = 118) orientation of the bevel tip. Epidural needle placement was confirmed in 96.4% (n = 213) of cases. Nonepidural needle placement was most commonly associated with superior lamina approach and caudal bevel tip orientation, which was marginally significant (adjusted risk ratio, 6.88; 95% CI, 0.93-∞; p = 0.059). CONCLUSION: Inadvertent nonepidural needle penetration during fluoroscopically guided lumbar interlaminar ESI appears to be affected by approach, with superior lamina approach and caudal bevel tip orientation being the least favorable technique.

Metastatic Renal Cell Carcinoma Masquerading as Jugular Foramen Paraganglioma: A Role for Novel Magnetic Resonance Imaging.

OBJECTIVES: To describe a case of metastatic renal cell carcinoma (RCC) masquerading as a jugular foramen paraganglioma (JP). To compare imaging findings between skull base metastatic RCC and histologically proven paraganglioma. METHODS: A case of unexpected metastatic skull base RCC is reviewed. Computed tomography (CT) and magnetic resonance imaging (MRI) were compared between 3 confirmed cases of JP and our case of metastatic RCC. Diffusion-weighted MRI (DW-MRI) sequences and computed apparent diffusion coefficient (ADC) values were compared between these entities. RESULTS: A 55-year-old man presents with what appears clinically and radiographically to be JP. The tumor was resected, then discovered on postoperative pathology to be metastatic RCC. Imaging was retrospectively compared between 3 histologically confirmed cases of JP and our case of skull base RCC. The RCC metastasis was indistinguishable from JP on CT and traditional MRI but distinct by ADC values calculated from DW-MRI. CONCLUSIONS: Metastatic RCC at the skull base may mimic the clinical presentation and radiographic appearance of JP. The MRI finding of flow voids is seen in both paraganglioma and metastatic RCC. Diffusion-weighted MRI is able to distinguish these entities, highlighting its potential utility in distinguishing skull base lesions.

International Frontal Sinus Anatomy Classification and anatomic predictors of low-lying anterior ethmoidal arteries.

BACKGROUND: The International Frontal Sinus Anatomy Classification (IFAC) was introduced to more accurately characterize ethmoid and frontal sinus pneumatization patterns. The prevalence of IFAC cells and their anatomic associations have not been described. OBJECTIVE: The goal was to examine the prevalence of IFAC cells and determine radiologic features associated with a low-lying anterior ethmoidal artery (LAEA). METHODS: Imaging of adult patients who underwent computed tomographies from January 2015 to March 2016 were retrospectively reviewed by using the IFAC classification. We also measured the distance from the skull base to the anterior ethmoidal artery (AEA), the height of the lateral lamella of the cribriform plate, and anterior-posterior diameter from the anterior wall of the frontal sinus to the skull base (APF). Patients with a history of sinus surgery, trauma, malignancy, or congenital anomaly were excluded. Statistical analysis was performed by using Pearson correlation coefficients and χ2 tests. RESULTS: A total of 95 patients met the inclusion criteria. There was a significant association between supraorbital ethmoid cells and an LAEA (p < 0.001), with a significant effect size (φ = 0.276, p = 0.007). An inverse relationship was observed between Keros type I classification I and an LAEA (p < 0.001), with a significant effect size (φ = -0.414, p = 0.000). Significant associations were found between the AEA distance from the skull base and the cribriform lateral lamella height (R = 0.576, p < 0.001). In addition, there was a significant association between the AEA distance from the skull base and the APF (R = 0.497, p < 0.001). CONCLUSION: The presence of a supraorbital ethmoid cell and a wide APF were associated with an LAEA. There was a significant relationship between Keros type I classification and the AEA adjacent to the skull base. Delineation of these anatomic relationships may be helpful during endoscopic sinus surgery to avoid complications.

Less Is More: Efficacy of Rapid 3D-T2 SPACE in ED Patients with Acute Atypical Low Back Pain.

RATIONALE AND OBJECTIVES: Emergency department (ED) patients with acute low back pain (LBP) may present with ambiguous clinical findings that pose diagnostic challenges to exclude cauda equina syndrome (CES). As a proof of concept, we aimed to determine the efficacy of a rapid lumbar spine (LS) magnetic resonance imaging (MRI) screening protocol consisting of a single 3D-T2 SPACE FS (3D-T2 Sampling Perfection with Application optimized Contrasts using different flip angle Evolution fat saturated) sequence relative to conventional LS MRI to exclude emergently treatable pathologies in this complex patient population. MATERIALS AND METHODS: LS MRI protocol including a sagittal 3D-T2 SPACE FS pulse sequence was added to the routine for ED patients presenting with acute atypical LBP over a 12-month period. Imaging findings were categorically scored on the 3D-T2 SPACE FS sequence and separately on the reference standard conventional LS MRI sequences. Patients' symptoms were obtained from review of the electronic medical record. Descriptive test statistics were performed. RESULTS: Of the 206 ED patients who obtained MRI for acute atypical LBP, 118 (43.3 ± 13.5 years of age; 61 female) were included. Specific pathologies detected on reference standard conventional MRI included disc herniation (n = 30), acute fracture (n = 3), synovial cyst (n = 3), epidural hematoma (n = 2), cerebrospinal fluid leak (n = 1), and leptomeningeal metastases (n = 1), and on multiple occasions these pathologies resulted in nerve root impingement (n = 36), severe spinal canal stenosis (n = 13), cord/conus compression (n = 2), and cord signal abnormality (n = 2). The 3D-T2 SPACE FS sequence was an effective screen for fracture (sensitivity [sens] = 100%, specificity [spec] = 100%), cord signal abnormality (sens = 100%, spec = 99%), and severe spinal canal stenosis (sens = 100%, spec = 96%), and identified cord compression not seen on reference standard. Motion artifact was not seen on the 3D-T2 SPACE FS but noted on 8.5% of conventional LS MRI. CONCLUSIONS: The 3D-T2 SPACE FS sequence MRI is a rapid, effective screen for emergently actionable pathologies that might be a cause of CES in ED patients presenting with acute atypical LBP. As this abbreviated, highly sensitive sequence requires a fraction of the acquisition time of conventional LS MRI, it has the potential of contributing to increased efficiencies in the radiology department and improved ED throughput.

Differentiation of Benign and Malignant Head and Neck Lesions With Diffusion Tensor Imaging and DWI.

OBJECTIVE: The purpose of this study was to determine whether diffusion tensor imaging (DTI) can be used to differentiate between benign and malignant head and neck lesions. MATERIALS AND METHODS: This retrospective study included patients with head and neck lesions who underwent clinical MRI at 1.5 or 3 T with DWI or DTI parameters. ROI analysis was performed, with lesion-to-medulla apparent diffusion coefficient (ADC) ratios generated. RESULTS: Sixty-five patients with head and neck lesions were included (71 benign, 40 malignant). Twenty-one patients had multiple lesions. Statistically significant differences (p < 0.001) were seen in the mean ADC values ± SD of malignant and benign lesions (0.55 × 10-3 ± 0.14 × 10-3 mm2/s vs 0.89 × 10-3 ± 0.29 × 10-3 mm2/s, respectively) and in the mean ADC ratios of malignant and benign lesions (0.88 ± 0.21 vs 1.40 ± 0.44, respectively) with DTI parameters. DTI and DWI parameters produced similar mean ADC ratio values for malignant (0.88 ± 0.21 and 0.92 ± 0.54, respectively) and benign lesions (1.40 ± 0.44 and 1.79 ± 0.52, respectively). ADC ratio thresholds for predicting malignancy for DTI (ADC ratio ≤ 1) and DWI (ADC ratio ≤ 0.94) were also similar. CONCLUSION: DTI is a useful predictor of malignancy for head and neck lesions, with ADC values of malignant lesions significantly lower than those of benign lesions. DTI ADC values were lower than DWI ADC values for all head and neck lesions in our study group, often below reported malignant DWI threshold values. Normalization of ADC values to an internal control resulted in similar ADC ratios on DWI and DTI.

Imaging and Outcomes for a New Entity: Low-Grade Sinonasal Sarcoma with Neural and Myogenic Features.

Objectives Low-grade sinonasal sarcoma with neural and myogenic features (LGSSNMF) is a new, rare tumor. Our goal is to describe the imaging characteristics and surgical outcomes of this unique skull base malignancy. Design Retrospective case series. Setting Academic medical center. Participants There were three patients who met inclusion criteria with a confirmed LGSSNMF. Main Outcome Measures Imaging and histopathological characteristics, treatments, survival and recurrence outcomes, complications, morbidity, and mortality. Results Patients presented with diplopia, facial discomfort, a supraorbital mass, and nasal obstruction. Magnetic resonance imaging and computed tomography imaging in all cases showed an enhancing sinonasal mass with associated hyperostotic bone formation that involved the frontal sinus, invaded the lamina papyracea and anterior skull base, and had intracranial extension. One patient underwent a purely endoscopic surgical resection and the second underwent a craniofacial resection, while the last is pending treatment. All patients recovered well, without morbidity or long-term complications, and are currently without evidence of disease (mean follow-up of 2.1 years). One patient recurred after 17 months and underwent a repeat endoscopic skull base and dural resection. Conclusions The surgical outcomes and imaging of this unique, locally aggressive skull base tumor are characterized.

Bilateral parotid oncocytoma with spontaneous intratumoral hemorrhage: a rare hypervascular parotid tumor with ASL perfusion.

We present a rare case of bilateral parotid oncocytoma with spontaneous intratumoral hemorrhage. Magnetic resonance imaging revealed multiple, bilateral, well-defined masses within the parotid glands with increased vascularity based on arterial spin labeling Magnetic Resonance (MR) perfusion imaging and restricted diffusion on diffusion-weighted imaging. During the clinical follow-up, the patient developed extensive hemorrhage from the largest tumor, presumably due to a combination of the hypervascular nature of oncocytoma and hemodialysis.

Nonparaganglioma jugular foramen tumors.

This article discusses the epidemiology, presentation, and diagnostic work-up of nonparaganglioma jugular foramen tumors, and the management options and predicted outcomes. Paragangliomas are the most common jugular foramen tumors, but other nonparagangliomas are important to consider in a differential for jugular foramen tumors. This article specifically focuses on jugular foramen schwannomas, meningiomas, metastatic disease, and regional pathologies that may extend to the jugular foramen, such as endolymphatic sac tumors, chordomas, and chondrosarcomas. Operative approaches to these tumors are also reviewed.