Planning Angiography for 90Y-Radioembolization Demonstrates a Variety of Unusual Extrahepatic Perfusion Patterns.

ABSTRACT: In preparation for 90Y radioembolization for hepatic malignancies, hepatic angiography is performed with intra-arterial delivery of 99mTc-macroaggregated albumin (MAA), known as premapping. This initial procedure allows for evaluation of standard/variant hepatic arterial anatomy using MAA as a surrogate marker for the delivery of 90Y to visualize the likely distribution of 90Y. Premapping allows for the assessment of at-risk extrahepatic targets and for the quantification of hepatopulmonary shunting. We present cases where MAA scintigraphic images reveal unusual perfusion patterns in hepatic cancers, treated with 90Y glass microspheres (Therasphere; Boston Scientific, Marlborough, MA).

Molecular imaging for evaluation of synovitis associated with osteoarthritis: a narrative review.

Recent evidence highlights the role of low-grade synovial inflammation in the progression of osteoarthritis (OA). Inflamed synovium of OA joints detected by imaging modalities are associated with subsequent progression of OA. In this sense, detecting and quantifying synovitis of OA by imaging modalities may be valuable in predicting OA progressors as well as in improving our understanding of OA progression. Of the several imaging modalities, molecular imaging such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT) has an advantage of visualizing the cellular or subcellular events of the tissues. Depending on the radiotracers used, molecular imaging method can potentially detect and visualize various aspects of synovial inflammation. This narrative review summarizes the recent progresses of imaging modalities in assessing inflammation and OA synovitis and focuses on novel radiotracers. Recent studies about imaging modalities including ultrasonography (US), magnetic resonance imaging (MRI), and molecular imaging that were used to detect and quantify inflammation and OA synovitis are summarized. Novel radiotracers specifically targeting the components of inflammation have been developed. These tracers may show promise in detecting inflamed synovium of OA and help in expanding our understanding of OA progression.

Polymorphous low-grade adenocarcinoma with cavernous sinus involvement presenting as third nerve palsy.

Purpose: Polymorphous low-grade adenocarcinoma is a tumor of the salivary glands that typically localizes within the oral cavity. We present a case of isolated third cranial nerve palsy as the initial presentation of polymorphous low-grade adenocarcinoma involving the left cavernous sinus in a patient status post glaucoma surgery. Observations: A 68-year-old woman status post glaucoma drainage device implantation in her left eye presented with an isolated left third nerve palsy ten weeks postoperatively. Differential diagnoses included microvascular ischemic neuropathy, postoperative ptosis, and compressive mass. MRI revealed a left cavernous sinus mass, and subsequent excisional biopsy revealed a diagnosis of polymorphous low-grade adenocarcinoma. Conclusions: There are few cases reporting polymorphous low-grade adenocarcinoma originating from and extending beyond the nasopharynx. This report emphasizes an unexpected neuro-ophthalmic manifestation of this salivary gland tumor.

Inappropriate requesting of parathyroid scintigraphy at an academic medical center.

BACKGROUND: Primary hyperparathyroidism is a biochemical, not radiologic diagnosis. Parathyroid scintigraphy should only be requested for surgical planning, not to confirm diagnosis. Here we determined reasons for inappropriately ordered parathyroid scintigraphy. METHODS: We generated a database of patients undergoing parathyroid scintigraphy over 5 years, who did not undergo parathyroidectomy. RESULTS: Over 5 years 129 parathyroid scintigraphies (of 308 total scans) were performed in patients who did not undergo parathyroidectomy. We determined that only 58 (45%) had true primary hyperparathyroidism. The most common reason for the scan was to "confirm the diagnosis." Only 20% were ordered for adenoma localization, although surgery was not performed. Physicians requesting parathyroid scintigraphies specialized in a variety of disciplines. CONCLUSION: Forty-two percent of parathyroid scintigraphies were requested inappropriately to "confirm" a diagnosis of primary hyperparathyroidism. We propose to change the ordering system to clarify that parathyroid scintigraphy is a functional tool to optimize surgery when the diagnosis is secure.

ACR-ABS-ACNM-ASTRO-SIR-SNMMI practice parameter for selective internal radiation therapy or radioembolization for treatment of liver malignancies.

PURPOSE: The American College of Radiology (ACR), American Brachytherapy Society (ABS), American College of Nuclear Medicine (ACNM), American Society for Radiation Oncology (ASTRO), Society of Interventional Radiology (SIR), and Society of Nuclear Medicine and Molecular Imaging (SNMMI) have jointly developed a practice parameter on selective internal radiation therapy (SIRT) or radioembolization for treatment of liver malignancies. Radioembolization is the embolization of the hepatic arterial supply of hepatic primary tumors or metastases with a microsphere yttrium-90 brachytherapy device. MATERIALS AND METHODS: The ACR -ABS -ACNM -ASTRO -SIR -SNMMI practice parameter for SIRT or radioembolization for treatment of liver malignancies was revised in accordance with the process described on the ACR website (https://www.acr.org/ClinicalResources/Practice-Parameters-and-Technical-Standards) by the Committee on Practice Parameters-Interventional and Cardiovascular Radiology of the ACR Commission on Interventional and Cardiovascular, Committee on Practice Parameters and Technical Standards-Nuclear Medicine and Molecular Imaging of the ACR Commission on Nuclear Medicine and Molecular Imaging and the Committee on Practice Parameters-Radiation Oncology of the ACR Commission on Radiation Oncology in collaboration with ABS, ACNM, ASTRO, SIR, and SNMMI. RESULTS: This practice parameter is developed to serve as a tool in the appropriate application of radioembolization in the care of patients with conditions where indicated. It addresses clinical implementation of radioembolization including personnel qualifications, quality assurance standards, indications, and suggested documentation. CONCLUSIONS: This practice parameter is a tool to guide clinical use of radioembolization. It focuses on the best practices and principles to consider when using radioemboliozation effectively. The clinical benefit and medical necessity of the treatment should be tailored to each individual patient.

Case report 68Ga-DOTATATE of optic nerve sheath meningioma.

We report a patient with an optic nerve sheath meningioma whose diagnosis and management were guided by using Gallium-68 DOTA-Tyr3-octreotatate (68Ga-DOTATATE). Positron Emission Tomography-Computed Tomography (PET-CT).

Transcatheter Arterial Embolization with n-Butyl Cyanoacrylate for the Treatment of Acquired Uterine Vascular Malformations.

PURPOSE: The purpose of the study was to evaluate the technique and outcomes of transcatheter arterial embolization (TAE) with n-butyl cyanoacrylate (NBCA) for the treatment of acquired uterine arteriovenous malformations (AVMs). MATERIALS AND METHODS: A retrospective review identified five women treated for suspected acquired uterine AVMs with TAE at our institution. Four women (80 %) presented with heavy or intermittent vaginal bleeding after obstetric manipulation. One woman (20 %) was treated for an incidental AVM discovered on ultrasound after an uncomplicated cesarean section. Three women underwent one embolization procedure and two women required two procedures. Embolization material included NBCA in six procedures (80 %) and gelatin sponge in one procedure (20 %). RESULTS: Embolization resulted in angiographic stasis of flow in all seven procedures. Four women (80 %) presented with vaginal bleeding which was improved after treatment. One woman returned 24 days after unilateral embolization with recurrent bleeding, which resolved after retreatment. One woman underwent two treatments for an asymptomatic lesion identified on ultrasound. There were no major complications. Three women (60 %) experienced mild postembolization pelvic pain that was controlled with non-steroidal anti-inflammatory drugs. Three women (60 %) had pregnancies and deliveries after embolization. CONCLUSIONS: TAE is a safe alternative to surgical therapy for acquired uterine AVMs with the potential to maintain fertility. Experience from this case series suggests that NBCA provides predictable and effective occlusion.

Axon fasciculation defects and retinal dysplasias in mice lacking the immunoglobulin superfamily adhesion molecule BEN/ALCAM/SC1.

The immunoglobulin superfamily adhesion molecule BEN (other names include ALCAM, SC1, DM-GRASP, neurolin, and CD166) has been implicated in the control of numerous developmental and pathological processes, including the guidance of retinal and motor axons to their targets. To test hypotheses about BEN function, we disrupted its gene via homologous recombination and analyzed the resulting mutant mice. Mice lacking BEN are viable and fertile, and display no external morphological defects. Despite grossly normal trajectories, both motor and retinal ganglion cell axons fasciculated poorly and were occasionally misdirected. In addition, BEN mutant retinae exhibited evaginated or invaginated regions with photoreceptor ectopias that resembled the "retinal folds" observed in some human retinopathies. Together, these results demonstrate that BEN promotes fasciculation of multiple axonal populations and uncover an unexpected function for BEN in retinal histogenesis.

A postmitotic role for Isl-class LIM homeodomain proteins in the assignment of visceral spinal motor neuron identity.

LIM homeobox genes have a prominent role in the regulation of neuronal subtype identity and distinguish motor neuron subclasses in the embryonic spinal cord. We have investigated the role of Isl-class LIM homeodomain proteins in motor neuron diversification using mouse genetic methods. All spinal motor neuron subtypes initially express both Isl1 and Isl2, but Isl2 is rapidly downregulated by visceral motor neurons. Mouse embryos lacking Isl2 function exhibit defects in the migration and axonal projections of thoracic level motor neurons that appear to reflect a cell-autonomous switch from visceral to somatic motor neuron character. Additional genetic mutations that reduce or eliminate both Isl1 and Isl2 activity result in more pronounced defects in visceral motor neuron generation and erode somatic motor neuron character. Thus, an early phase of high Isl expression and activity in newly generated motor neurons permits the diversification of visceral and somatic motor neuron subtypes in the developing spinal cord.

Fine-tuning motor neuron properties: signaling from the periphery.

Our understanding of motor neuron differentiation is rapidly evolving. New studies demonstrate that cells in the periphery of the embryo provide feedback signals for spinal cord motor neurons that are instrumental in the timing and regulation of their development. Two papers in this issue of Neuron identify a motor neuron survival factor, GDNF, and the ETS transcription factor, PEA3, as key components of a signal transduction pathway whose goals are 2-fold: to cluster motor pool-specific cell bodies and to promote axon arborization.