BACKGROUND Chronic subdural hematoma (SDH) is a particularly challenging pathology due to high recurrence rates (2%-37%) and complex medical comorbidities that tend to afflict the patient population. Recently, there have been several case series published describing the use of middle meningeal artery (MMA) embolization as an alternative to surgery for treatment of new or recurrent chronic SDH. OBJECTIVE To describe our first 60 cases of MMA embolization for chronic SDH. METHODS MMA embolization was performed using angiography, selective microcatheterization of the MMA, and infusion of polyvinyl alcohol particles. Outcomes were assessed clinically and with interval imaging studies at 1 d, 2 wk, and 6 wk postprocedure, and additional intervals as indicated. RESULTS MMA embolization was performed successfully on 60 total SDHs in 49 patients. This includes upfront treatment for new (not previously treated) SDH in 42, for recurrence in 8, and prophylaxis (soon after surgical evacuation) in 10. There were 3 mortalities (unrelated to the procedure), and no procedural complications. Of the 50 nonprophylactic cases, there were 4 (8.9%) cases of recurrence requiring surgical evacuation, and 31 (68.9%) that had resolution or reduction in size >50% of SDH at longest follow-up. Overall, 41 (91.1%) were stable or decreased in size and able to avoid surgery. CONCLUSION MMA embolization may represent a minimally-invasive alternative to surgery for new or recurrent chronic SDH, or as prophylaxis to reduce the risk of recurrence after surgery. Given our encouraging results with a 91% long-term success rate, a large scale clinical trial is warranted.

Purpose:To develop microcapsules that immunoprotect pancreatic islet cells for treatment of type I diabetes and enable multimodal cellular imaging of transplanted islet cells. Materials and Methods:All animal experiments were approved by the institutional animal care and use committee. Gold nanoparticles functionalized with DTDTPA (dithiolated diethylenetriaminepentaacetic acid):gadolinium chelates (GG) were coencapsulated with pancreatic islet cells by using protamine sulfate as a clinical-grade alginate cross linker. Conventional poly-Llysine-cross-linked microcapsules and unencapsulated islets were included as controls. The viability and glucose responsiveness of islet cells were assessed in vitro, and in vivo insulin (C-peptide) secretion was monitored for 6 weeks in (streptozotocin-induced) diabetic mice with ( n = 7) or without ( n = 8) intraabdominally engrafted islet cells. Five nondiabetic mice were included as controls. Differences between samples were calculated by using a nonparametric Wilcoxon Mann-Whitney method. To adjust for multiple comparisons, a signifi cance level of P , .01 was chosen. Generalized estimating equations were used to model cell function over time. Three mice with engrafted capsules were imaged in vivo with high-fi eld-strength (9.4-T) magnetic resonance (MR) imaging, micro-computed tomography (CT), and 40-MHz ultrasonography (US). Results:Encapsulated human pancreatic islets were functional in vitro for at least 2 weeks after encapsulation. Blood glucose levels in the diabetic mice transplanted with GG-labeled encapsulated mouse b TC6 insulinoma cells returned to normal within 1 week after transplantation, and normoglycemia was sustained for at least 6 weeks without the use of immunosuppressive drugs. GG microcapsules could be readily visualized with positive-contrast high-fi eld-strength MR imaging, micro-CT, and US both in vitro and in vivo. Conclusion:Cell encapsulation with GG provides a means of trimodal noninvasive tracking of engrafted cells.

Background and purpose Embolization of the middle meningeal artery (MMA) has recently been proposed as an alternative to surgery for treatment of chronic subdural hematoma (SDH), and several case reports have been published supporting its efficacy. It has been suggested that the primary pathologic process in chronic SDH is repeated microhemorrhaging into the subdural collection from fragile neovasculature within the SDH membrane that arises from distal branches of the MMA. Embolization could thus provide a means of eliminating this chronic rebleeding. Materials and methods Images were selected from MMA embolization procedures performed at our institution in order to illustrate the technique and theory behind its efficacy for treatment of chronic SDH. Results Images from MMA angiograms demonstrate the variability of MMA anatomy and help illustrate the importance of avoiding potential ophthalmic collaterals and branches supplying cranial nerves. The findings of irregular wispiness of the distal MMA vasculature, contrast outlining of the SDH membrane on angiography, and homogenous increased density within the SDH on postembolization head computed tomography are described. Conclusion MMA embolization may provide a safe alternative for treatment of chronic SDH, but careful angiographic assessment of MMA anatomy should be performed to avoid potential complications. The findings illustrated here lend support to the theory that the pathologic process of chronic SDH is repeated leakage of blood products from an inflamed, abnormal arterial neovasculature within the SDH membrane that arises from the MMA, and thus selective embolization could provide an effective treatment.

MMA embolization could present a minimally invasive and low-risk initial treatment alternative to surgery for symptomatic chronic SDH when clinically appropriate.

The overall survival of patients with thalamic glioblastoma is comparable to unresectable lobar supratentorial GBMs. Younger patients and those with good presenting functional status had improved survival. Midbrain involvement by the tumor is not a negative prognostic factor. Improved therapies are needed, and patients should be considered for early trial involvement and aggressive upfront therapy.

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Understanding how individual cells behave inside living systems will help enable new diagnostic tools and cellular therapies. Superparamagnetic iron oxide (SPIO) particles can be used to label cells and theranostic capsules for non-invasive tracking using MRI. Contrast changes from SPIO are often subtle relative to intrinsic sources of contrast, presenting a detection challenge. Here we describe a versatile post-processing method, called Phase map cross-correlation Detection and Quantification (PDQ), that automatically identifies localized deposits of SPIO, estimating their volume magnetic susceptibility and magnetic moment. To demonstrate applicability, PDQ was used to detect and characterize SPIO-labeled magnetocapsules implanted in porcine liver and suspended in agarose gel. PDQ was also applied to mouse brains infiltrated by MPIO-labeled macrophages following traumatic brain injury (TBI); longitudinal, in vivo studies tracked individual MPIO clusters over three days, and tracked clusters were corroborated in ex vivo brain scans. Additionally, we applied PDQ to rat hearts infiltrated by MPIO-labeled macrophages in a transplant model of organ rejection. PDQ magnetic measurements were SNR-invariant for images with SNR>11. PDQ can be used with conventional gradient-echo pulse sequences, requiring no extra scan time. The method is useful for visualizing biodistribution of cells and theranostic magnetocapsules, and for measuring their relative iron content.

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