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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Progression of vasogenic edema induced by activated microglia under permanent middle cerebral artery occlusion

Highlights: • Vasogenic edema was visualized by superimposing TTC staining on T2WI. • Vasogenic edema moved from the ischemic core to the peripheral region. • Microglial activation was spread from the ischemic core to the peripheral region. • Microglial inhibition suppressed the progression of vasogenic edema. • Microglia are involved in vasogenic edema progression in ischemic stroke. Brain edema is a severe complication that accompanies ischemic stroke. Increasing evidence shows that inflammatory cytokines impair tight junctions of the blood-brain barrier, suggesting the involvement of microglia in brain edema. In this study, we examined the role of microglia in the progression of ischemic brain edema using mice with permanent middle cerebral artery occlusion. The intensity of T2-weighted imaging (T2WI) in the cerebral cortex and the striatum was elevated 3 h after occlusion and spread to peripheral regions of the ischemic hemisphere. Merged images of 2,3,5-triphenyl tetrazolium chloride staining and T2WI revealed the exact vasogenic edema region, which spread from the ischemic core to outside the ischemic region. Microglia were strongly activated in the ischemic region 3 h after occlusion and, notably, activated microglia were observed in the non-ischemic region 24 h after occlusion. Pretreatment with minocycline, an inhibitor of microglial activation clearly suppressed not only vasogenic edema but also infarct formation. We demonstrated in this study that vasogenic edema spreads from the ischemic core to the peripheral region, which can be elicited, at least in part, by microglial activation induced by ischemia.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Corpus luteum with ovarian stromal edema is associated with pelvic pain and confusion for ovarian torsion

Purpose: To distinguish the corpus luteum with adjacent ovarian stromal edema as an entity associated with pelvic pain, with confounding ultrasound features that may lead to false-positive diagnosis of ovarian torsion. Methods: This is a blinded, retrospective study of 243 corpora lutea on transvaginal ultrasound. Imaging parameters included ovarian and corpus luteum volumes, central cystic space within the corpus luteum, vascularity around the corpus luteum, peripherally displaced follicles, and complex free fluid. Residual volume (ovarian volume minus corpus luteum volume) was used as a surrogate for ovarian stromal edema. Clinical parameters included age, pregnancy, and location/acuity of pain if present. Concern for ovarian torsion in radiology reports was documented. Results: 51.0% (124/243) of patients presented with pain. Multivariate regression analysis of factors significantly associated with pain (including age, p = 0.001; larger corpus luteum volume, p = 0.002; larger residual volume, p < 0.001; complex free fluid, p = 0.002; and peripherally displaced follicles, p < 0.001) left only increased residual volume as significantly associated with pain [OR 1.02–1.16; p = 0.01]. False-positive concern for ovarian torsion on ultrasound was present in 12.9% (16/124) of patients with pain, associated with enlarged ovaries (p < 0.001) and peripherally displaced follicles (p < 0.001). High correlation between location of pain and side of the corpus luteum was demonstrated in patients with pain < 14 days duration (p < 0.001). Conclusion: Corpus luteum with ovarian stromal edema is associated with pelvic pain and can mimic ovarian torsion on ultrasound. Further research should explore diagnostically useful differences between cases of ovarian torsion and cases of ovarian edema related to corpora lutea.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Hypertonic saline regulates microglial M2 polarization via miR-200b/KLF4 in cerebral edema treatment

Highlights: • Hypertonic saline (HS) alleviates cerebral edema via regulating neuroinflammation. • miR-200b/KLF4 regulates microglial M2 polarization during HS treatment. • KLF4 directly binds to Arg1 promoter and induces its transcription. • Modulation of KLF4 in vivo affects HS treatment of cerebral edema. Hypertonic saline (HS) has been used clinically for treatment of cerebral edema for decades. Previously we have demonstrated that HS alleviates cerebral edema via regulating water/ion channel protein and attenuating neuroinflammation. However, whether HS treatment triggers microglia polarization and its regulatory mechanism during this process is unclear.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Central Corneal Edema with Scleral-Lens Wear

Purpose: To assess the safety of scleral-lens designs, we model and clinically assess central corneal edema induced by scleral-lens wear for healthy subjects. Materials and Methods: Typically, central corneal swelling during scleral-lens wear is measured using optical coherence tomography (OCT). Transport resistances are modeled for oxygen diffusion through the scleral lens and post-lens tear-film (PoLTF), and into the cornea. Oxygen deficiency in the cornea activates anaerobic metabolic reactions that induce corneal edema. Oxygen permeability, carbon-dioxide permeability, settled-lens PoLTF thickness, and scleral-lens thickness are varied in the calculations to mimic different lens fits. Results: Transport modeling predicts that for open eyes, increasing PoLTF thickness from 50 to 400 µm increases central corneal swelling by approximately 1–1.5% when oxygen transmissibility ( Dk/L ) is greater than 10 hBarrer/cm (i.e., hectoBarrer/cm). Although swelling is larger for oxygen Dk/L < 10 hBarrer/cm, PoLTF thickness has minimal impact in this range. For open eye, oxygen transmissibility of the lens plays a significant role in corneal edema, but is negligible when oxygen Dk/L is > 40 hBarrer/cm. For closed eye, central corneal swelling is greater than 5% for an oxygen Dk/L range of 0–100 hBarrer/cm with typical lens-fitting parameters. For carbon-dioxide transmissibilities increasing from 50 to 250 hBarrer/cm and with a fixed oxygen Dk/L of 25 hBarrer/cm, calculated swelling diminishes by an additional 0.5%. Comparison of model calculations to clinical-swelling data is within the error range of the clinical measurements. Conclusions: Oxygen/metabolite transport calculations for open-eye scleral-lens wear demonstrate that normal PoLTF thicknesses fitted by clinicians (i.e., PoLTF thicknesses < 400 µm) with modern scleral lenses (i.e., oxygen Dk/L > 25 hBarrer/cm) produce corneal swelling of less than 2% in agreement with experiment. Therefore, scleral lenses prescribed today evoke less than physiological hypoxic swelling (i.e., less than 4%) for healthy corneas during open-eye. Closed-eye wear, however, appears clinically unsafe.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Lysophosphatidic acid receptor, LPA6, regulates endothelial blood-brain barrier function: Implication for hepatic encephalopathy

Highlights: • Serum autotaxin activity is elevated in the mouse with brain edema. • LPA{sub 6} is predominantly expressed in rat brain capillary endothelial cells. • LPA–LPA{sub 6}–G{sub 12/13}–Rho pathway regulates blood brain barrier permeability. Cerebral edema is a life-threatening neurological condition characterized by brain swelling due to the accumulation of excess fluid both intracellularly and extracellularly. Fulminant hepatic failure (FHF) develops cerebral edema by disrupting blood-brain barrier (BBB). However, the mechanisms by which mediator induces brain edema in FHF remain to be elucidated. Here, we assessed a linkage between brain edema and lysophosphatidic acid (LPA) signaling by utilizing an animal model of FHF and in vitro BBB model. Azoxymethane-treated mice developed FHF and hepatic encephalopathy, associated with higher autotaxin (ATX) activities in serum than controls. Using in vitro BBB model, LPA disrupted the structural integrity of tight junction proteins including claudin-5, occludin, and ZO-1. Furthermore, LPA decreased transendothelial electrical resistances in in vitro BBB model, and induced cell contraction in brain endothelial monolayer cultures, both being inhibited by a Rho-associated protein kinase inhibitor, Y-27632. The brain capillary endothelial cells predominantly expressed LPA{sub 6} mRNA, whose knockdown blocked the LPA-induced endothelial cell contraction. Taken together, the up-regulation of serum ATX in hepatic encephalopathy may activate the LPA–LPA{sub 6}–G{sub 12/13}–Rho pathway in brain capillary endothelial cells, leading to enhancement of BBB permeability and brain edema.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Temporal changes in MRI appearance of the prostate after focal ablation

Purpose: The purpose of our study was to retrospectively evaluate and categorize temporal changes in MRI appearances of the prostate in patients who underwent focal therapy with MRI follow-up. Methods: The Institutional Review Board approved this retrospective study and waived the requirement for informed consent. Thirty-seven patients (median age 61; 48–70 years) with low-to-intermediate-risk, clinically organ-confined prostate cancer underwent focal ablation therapy from 2009 to 2014. Two radiologists reviewed post-treatment MRIs (n = 76) and categorized imaging features blinded to the time interval between the focal therapy and the follow-up MRI. Inter-reader agreement was assessed (kappa) and generalized linear regression was used to examine associations between an imaging feature being present/absent and days between ablation and MRI. Results: Inter-reader agreement on MRI features ranged from fair to substantial. Edema was found present at earlier times after ablation (median 16–25 days compared to MRIs without edema, median 252–514 days), as was rim enhancement of the ablation zone (18–22.5 days vs. 409–593 days), a hypointense rim around the ablation zone on T2-weighted images (53-57.5 days vs. 279–409 days) and the presence of an appreciable ablation cavity (48.5–60 days vs. 613–798 days, all p < 0.05). Enhancement of the ablation zone/scar (553–731 days vs. 61.5–162 days) and the formation of a T2-hypointense scar were found to be present on later MRI scans (514–553 days vs. 29–32 days, one reader). Conclusions: The MRI appearance of the prostate after focal ablation changes substantially over time. Identification of temporal patterns in the appearance of imaging features should help reduce image interpretation variability and errors when assessing post-therapeutic scans.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

A deficiency of the GluN2C subunit of the N-methyl-D-aspartate receptor is neuroprotective in a mouse model of ischemic stroke

Highlights: • GluN2C{sup -/-} mice have less edema, neurological deficit, and weight loss after stroke. • GluN2C{sup -/-} mice display increased neuronal integrity and decreased tauopathy. • GluN2C{sup -/-} mice display less Fyn and phosphorylation of extrasynaptic GluN2B(Y1336). • GluN2C{sup -/-} mice display increased localization of P-CREB(S133) in the nucleus. The N-methyl-D-aspartate receptor (NMDAR) ion channel plays a pivotal role in the pathology of ischemic stroke. The functional receptor consists of two GluN1 subunits (a-h) and two GluN2 subunits (A/B/C/D), the expression of which are spatially and temporally regulated in pathological and physiological conditions. While the roles of the GluN2A and GluN2B subunit in ischemic stroke have been well developed, the role of the GluN2C subunit in ischemia is not well understood. Following middle carotid artery occlusion (MCAO), GluN2C{sup -/-} male mice displayed similar volumes of infarct as wild-type (WT) mice. However, GluN2C{sup -/-} mice showed decreased cerebral edema and an enhanced rate of neurological recovery compared to WT mice. The ischemic penumbra of GluN2C{sup -/-} mice showed fewer cytoarchitectural deficits and decreased tauopathy relative to WT mice. These neuroprotective changes in GluN2C{sup -/-} mice also corresponded with decreased expression of Fyn kinase and decreased phosphorylation of GluN2B subunit at Tyr1336. Lastly, a GluN2C deficiency modified the NMDAR/pro-survival signaling axis, as shown by increased levels of nuclear CREB(P-Ser133). Thus, the GluN2C subunit enhances ischemic stroke pathology by promoting neuronal dysfunction in the penumbra region.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Preservation of rat hearts in subfreezing temperature isochoric conditions to – 8 °C and 78 MPa

Highlights: • A novel method of low-temperature organ preservation is tested using rat hearts. • Isochoric systems allow ice-free preservation at temperatures well below freezing. • Conventional heart preservation employs on-ice storage in atmospheric conditions. • Histological quality is improved in hearts preserved in a −4 °C isochoric system. Isochoric (constant volume) preservation at subfreezing temperatures is being investigated as a novel method for preserving cells and organs. This study is a first initial effort to evaluate the efficacy of this method for heart preservation, and to provide a preliminary outline of appropriate preservation parameters. To establish a baseline for further studies, rat hearts were preserved in a University of Wisconsin (UW) intracellular solution for one hour under isochoric conditions at: 0 °C (atmospheric pressure - 0.1 MPa), - 4 °C (41 MPa), - 6 °C (60 MPa) and – 8 °C (78 MPa). The viability of the heart was evaluated using Langendorff perfusion and histological examination. The physiological performance of hearts preserved at – 4 °C (41 MPa) was comparable to that of a heart preserved on ice at atmospheric pressure, with no statistically significant difference in histological injury score. However, hearts preserved at −4 °C displayed substantially reduced interstitial edema compared to hearts preserved by conventional hypothermic preservation in UW on ice at atmospheric pressure, suggesting significant protection from increased vascular permeability following preservation. Hearts preserved at – 6 °C (60 MPa) suffered injury from cellular swelling and extensive edema, and at – 8 °C (78 MPa) hearts experienced significant morphological disruption. To the best of our knowledge, this is the first publication showing that a mammalian organ can survive low subfreezing temperatures without the use of a cryoprotective additive. Lowering the preservation temperature reduces metabolism and improves preservation quality, and these results suggest that improvements in preservation are possible at subzero temperatures with low to moderate pressures observed at −4 °C. Notably, tissue damage was observed at lower temperatures (−6 °C or below) accompanying further elevation of pressure associated with isochoric preservation that may prove detrimental. Therefore, subfreezing temperature isochoric preservation protocols should optimize, a combination of temperature and pressure that will minimize the negative effects of elevated pressure while retaining the beneficial effect of lower temperatures and reduced metabolism.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Sodium benzoate induced developmental defects, oxidative stress and anxiety-like behaviour in zebrafish larva

Highlights: • Sodium benzoate induced developmental defects in zebrafish. • Sodium benzoate induced oxidative stress in zebrafish by upregulation of glutathione reductase (gsr). • Sodium benzoate induced anxiety-like behaviour in zebrafish. Sodium benzoate (SB) is a common food preservative. Its FDA described safety limit is 1000 ppm. Lately, increased use of SB has prompted investigations regarding its effects on biological systems. Data regarding toxicity of SB is divergent and controversial with studies reporting both harmful and beneficial effects. Therefore, we did a systematic dose dependent toxicity study of SB using zebrafish vertebrate animal model. We also investigated oxidative stress and anxiety-like behaviour in zebrafish larva treated with SB. Our results indicate that SB induced developmental (delayed hatching), morphological (pericardial edema, yolk sac edema and tail bending), biochemical (oxidative stress) and behavioural (anxiety-like behaviour) abnormalities in developing zebrafish larva. LC{sub 50} of SB induced toxicity was approximately 400 ppm after 48 h of SB exposure. Our study strongly supports its harmful effects on vertebrates at increasing doses. Thus, we suggest caution in the excessive use of this preservative in processed and convenience foods.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Acute lung injury and persistent small airway disease in a rabbit model of chlorine inhalation

Chlorine is a pulmonary toxicant to which humans can be exposed through accidents or intentional releases. Acute effects of chlorine inhalation in humans and animal models have been well characterized, but less is known about persistent effects of acute, high-level chlorine exposures. In particular, animal models that reproduce the long-term effects suggested to occur in humans are lacking. Here, we report the development of a rabbit model in which both acute and persistent effects of chlorine inhalation can be assessed. Male New Zealand White rabbits were exposed to chlorine while the lungs were mechanically ventilated. After chlorine exposure, the rabbits were extubated and were allowed to survive for up to 24 h after exposure to 800 ppm chlorine for 4 min to study acute effects or up to 7 days after exposure to 400 ppm for 8 min to study longer term effects. Acute effects observed 6 or 24 h after inhalation of 800 ppm chlorine for 4 min included hypoxemia, pulmonary edema, airway epithelial injury, inflammation, altered baseline lung mechanics, and airway hyperreactivity to inhaled methacholine. Seven days after recovery from inhalation of 400 ppm chlorine for 8 min, rabbits exhibited mild hypoxemia, increased area of pressure–volume loops, and airway hyperreactivity. Lung histology 7 days after chlorine exposure revealed abnormalities in the small airways, including inflammation and sporadic bronchiolitis obliterans lesions. Immunostaining showed a paucity of club and ciliated cells in the epithelium at these sites. These results suggest that small airway disease may be an important component of persistent respiratory abnormalities that occur following acute chlorine exposure. This non-rodent chlorine exposure model should prove useful for studying persistent effects of acute chlorine exposure and for assessing efficacy of countermeasures for chlorine-induced lung injury. - Highlights: • A novel rabbit model of chlorine-induced lung disease was developed. • Acute effects of chlorine were pulmonary edema, hypoxemia and impaired lung function. • Persistent small airway disease developed following recovery from acute injury. • Small airway disease included inflammation and bronchiolitis obliterans lesions. • The model should be useful for studying chlorine lung injury and testing treatments.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Cutaneous exposure to vesicant phosgene oxime: Acute effects on the skin and systemic toxicity

Phosgene Oxime (CX), an urticant or nettle agent categorized as a vesicant, is a potential chemical warfare and terrorist weapon. Its exposure can result in widespread and devastating effects including high mortality due to its fast penetration and ability to cause immediate severe cutaneous injury. It is one of the least studied chemical warfare agents with no effective therapy available. Thus, our goal was to examine the acute effects of CX following its cutaneous exposure in SKH-1 hairless mice to help establish a relevant injury model. Results from our study show that topical cutaneous exposure to CX vapor causes blanching of exposed skin with an erythematous ring, necrosis, edema, mild urticaria and erythema within minutes after exposure out to 8 h post-exposure. These clinical skin manifestations were accompanied with increases in skin thickness, apoptotic cell death, mast cell degranulation, myeloperoxidase activity indicating neutrophil infiltration, p53 phosphorylation and accumulation, and an increase in COX-2 and TNFα levels. Topical CX-exposure also resulted in the dilatation of the peripheral vessels with a robust increase in RBCs in vessels of the liver, spleen, kidney, lungs and heart tissues. These events could cause a drop in blood pressure leading to shock, hypoxia and death. Together, this is the first report on effects of CX cutaneous exposure, which could help design further comprehensive studies evaluating the acute and chronic skin injuries from CX topical exposure and elucidate the related mechanism of action to aid in the identification of therapeutic targets and mitigation of injury. - Highlights: • Phosgene oxime cutaneous exposure causes skin blanching, edema and urticaria. • Penetration of phosgene oxime causes dilation of vasculature in internal organs. • Mast cells could play an important role in phosgene oxime-induced skin injury. • Phosgene oxime could induce low blood pressure and hypoxia leading to mortality. • Data is significant for developing a phosgene oxime-induced skin injury model.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Functional relaxant effect of 6,7-dipropoxy-2H-chromen-2-one is mainly by calcium channel blockade in ex vivo assay of tracheal rings

Asthma is a prevalent disease characterized by airway chronic inflammation, airway hyperresponsiveness, edema and excess of mucus production. Molecules with coumarin scaffold have shown multiple biological effects, including anti-asthmatic. This study describes relaxant effect and mechanism of action of novel semisynthetic 6,7-dipropoxy-2H-chromen-2-one (6,7-DPC) on smooth muscle airways and in silico approaches. 6,7-DPC induced significant relaxant effect on tracheal rings pre-contracted with carbachol (E{sub max} = 100%; EC{sub 50} = 89 µM). Concentration-response curve of 6,7-DPC showed a significant shift to the left with respect to theophylline (positive control). Moreover, pre-treatment with 6,7-DPC inhibited the carbachol-induced contraction in a concentration-dependent manner with suppression of the maximum response. Also, KCl [80 mM]-induced contraction was partially abolished by 6,7-DPC compared with nifedipine; however, CaCl{sub 2} contraction curve only reached 30% of maximal response in the tissues pre-incubated with the test sample. 6,7-DPC was docked on an outer cavity located on the intracellular side of the human L-type calcium channel model and interacts in the following chains and residues: IIIS5.M26, IIIP.T45, IIIP.F49, IIIP.G51, IIIP.P53, IVP.C46, IVP.G49, IVP.E50, IVP.A51, IVP.W52, IVP.Q53, IVP.D54, IVS6.I4, IVS6.F7, IVS6.I8, IVS6.F10, and IVS6.F11. Also, nifedipine made unique interactions with IIIP.E50, IIIP.W52, IIIP.L55. Meanwhile, 6,7-DPC interacted with IIIS5.A22, IIIS2.Q27, and IVS6.C14, exclusively. In conclusion, 6,7-DPC showed a relaxant effect due to combined mechanism of action on rat tracheal rings, through non-competitive muscarinic receptor functional antagonism and preventing the calcium influx. This provides pharmacological basis for the use of 6,7-DPC in airways disorders, such as asthma or chronic obstructive pulmonary disease (COPD).

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Synthesis and anti-inflammatory activity of 1,2-3-substituted 2a1,4,5-triazacyclopenta[cd]indene derivatives

The present study reports the synthesis of 1,2-3-substituted-2a1,4,5-triazacyclopenta[cd]indene derivatives. The synthetic methodology includes some of the prominent reaction steps as specified in sequence (i) Bromination of acetophenones (ii) Condensation of 2-bromo-1-(substituted phenyl) ethanone derivatives with 2-aminopyrimidine, and (iii) Coupling of imidazo[1,2-a]pyrimidine derivatives with 1,2-diaryl/diaklylethynes. The structures of the newly synthesized derivatives have been determined by {sup 1}H NMR, {sup 13}C NMR, LC-MS, and IR spectral analysis. Furthermore, these derivatives were screened for their preliminary anti-inflammatory activities using Carrageenan induced paw edema test method. These promising screening results suggested a huge potential for the molecular diversity from present compounds that can be inflated to better lead candidates.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

A comparison of segmented abdominopelvic fluid volumes with conventional CT signs of abdominal compartment syndrome in a trauma population

Purpose: To compare the utility of abdominopelvic fluid volume measurements with established computed tomography signs for refractory post-traumatic abdominal compartment syndrome. Methods: This retrospective observational cohort study included 64 consecutive adult trauma patients with preoperative CT and diagnosis of refractory abdominal compartment syndrome requiring decompressive laparotomy at a level I trauma referral center between 2004 and 2014. We hypothesized that abdominal fluid volume measurements would be more predictive of the need for early laparotomy than previously described conventional CT signs of refractory ACS. Abdominopelvic fluid volumes were determined quantitatively using semi-automated segmentation software. The following conventional imaging parameters were recorded: abdominal anteroposterior:transverse ratio (round belly sign); infrahepatic vena cava diameter; distal abdominal aortic diameter; largest single small bowel wall diameter; hydronephrosis, inguinal herniation; and mesenteric and body wall edema. For outcome analysis, patients were stratified into two groups: those who underwent early (< 24 h) and late (≥ 24 h) decompressive laparotomy following CT. Correlation analysis, comparison of means, and multivariate logistic regression were performed. Results: Abdominal fluid volumes (p = 0.001) and anteroposterior:transverse ratio (p = 0.009) were increased and inferior vena cava diameter (p = 0.009) was decreased in the early decompressive laparotomy group. Multivariate analysis including conventional CT variables, fluid volumes, and laboratory values revealed abdominal fluid volumes (p = 0.012; Δ in log odds of 1.002/mL) as the only independent predictor of early decompressive laparotomy. Conclusions: Segmented abdominopelvic free fluid volumes had greater predictive utility for decision to perform early decompressive laparotomy than previously described ACS-related CT signs in trauma patients who developed refractory abdominal compartment syndrome.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Image-Guided Percutaneous Bleomycin and Bevacizumab Sclerotherapy of Orbital Lymphatic Malformations in Children

Purpose: To evaluate the effectiveness and safety of image-guided percutaneous sclerotherapy using bleomycin for macrocystic and bevacizumab (Avastin™) for microcystic orbital lymphatic malformations in children. Materials and Methods: Between October 2015 and July 2018, we prospectively evaluated 10 pediatric patients who presented clinically and radiologically with lymphatic malformations and were treated with percutaneous sclerotherapy. Patients with venous malformations were excluded. Eight females and two males with ages ranging from 3 to 17 years (mean: 8.8, SD: 4.9) were included. Guided with ultrasound and fluoroscopy, macrocysts were treated with bleomycin instillation. For microcystic components in three patients, bevacizumab was injected intralesional. All patients underwent ultrasound and non-contrast MRI to evaluate response to treatment after 6 weeks. Results: The malformations were macrocystic in seven patients and complex (macro/microcystic) in three. Twenty sclerotherapy sessions were performed, (range: 1–3 sessions, mean: 2, SD: 0.8). Clinically, there was a significant reduction in the proptosis after treatment (P = 0.007) and dystopia (P = 0.018). The local radiological response showed a reduction in the maximum lesions diameters and volumes after treatment (P = 0.005 and 0.005, respectively). Two of the three patients treated with bevacizumab showed a reduction in the lesions volumes by 90.4% and 63.4%, respectively, whereas one patient did not show volume reduction. Transient periorbital edema and ecchymosis occurred following the procedure with no major complications encountered. Follow-up ranged from 9–33 months, mean: 20.3, SD: 7.4. Conclusion: Bleomycin sclerotherapy is a safe and effective treatment for orbital macrocystic lymphatic malformations. Further use of bevacizumab for microcystic lesions in a larger series is required to outline its efficacy and safety.

62 RADIOLOGY AND NUCLEAR MEDICINE↗