Effect of Thrombin and Incubation Time on Porcine Whole Blood Clot Elasticity and Recombinant Tissue Plasminogen Activator Susceptibility.

Deep vein thrombosis is a major source of morbidity and mortality worldwide. Catheter-directed thrombolytics are the frontline approach for vessel recanalization, though fibrinolytic efficacy is limited for stiff, chronic thrombi. Although thrombin has been used in preclinical models to induce thrombosis, the effect on lytic susceptibility and clot stiffness is unknown.

Accelerated sonothrombolysis with Definity in a xenographic porcine cerebral thromboembolism model.

Adjuvant ultrasound at 2 MHz with or without an ultrasound contrast agent improves the rate of thrombus resolution by recombinant tissue plasminogen activator (rt-PA) in laboratory and clinical studies. A sub-megahertz approach can further expand this therapy to a subset of patients with an insufficient temporal bone window, improving efficacy in unselected patient populations. The aim of this study was to determine if a clinical ultrasound contrast agent (UCA), Definity, and 220 kHz pulsed ultrasound accelerated rt-PA thrombolysis in a preclinical animal model of vascular occlusion.

Diffuse reflectance spectroscopy for breach detection during pedicle screw placement: a first in vivo investigation in a porcine model.

Background: The safe and accurate placement of pedicle screws remains a critical step in open and minimally invasive spine surgery, emphasizing the need for intraoperative guidance techniques. Diffuse reflectance spectroscopy (DRS) is an optical sensing technology that may provide intraoperative guidance in pedicle screw placement.

Purpose: The study presents the first in vivo minimally invasive procedure using DRS sensing at the tip of a Jamshidi needle with an integrated optical K-wire.

Validation of diffuse reflectance spectroscopy with magnetic resonance imaging for accurate vertebral bone fat fraction quantification.

Safe and accurate placement of pedicle screws remains a critical step in open and minimally invasive spine surgery. The diffuse reflectance spectroscopy (DRS) technique may offer the possibility of intra-operative guidance for pedicle screw placement. Currently, Magnetic Resonance Imaging (MRI) is one of the most accurate techniques used to measure fat concentration in tissues.

Machine learning for automated 3-dimensional segmentation of the spine and suggested placement of pedicle screws based on intraoperative cone-beam computer tomography.

Objective: The goal of this study was to develop and validate a system for automatic segmentation of the spine, pedicle identification, and screw path suggestion for use with an intraoperative 3D surgical navigation system.

Methods: Cone-beam CT (CBCT) images of the spines of 21 cadavers were obtained. An automated model-based approach was used for segmentation.

Diffuse reflectance spectroscopy, a potential optical sensing technology for the detection of cortical breaches during spinal screw placement.

Safe and accurate placement of screws remains a critical issue in open and minimally invasive spine surgery. We propose to use diffuse reflectance (DR) spectroscopy as a sensing technology at the tip of a surgical instrument to ensure a safe path of the instrument through the cancellous bone of the vertebrae. This approach could potentially reduce the rate of cortical bone breaches, thereby resulting in fewer neural and vascular injuries during spinal fusion surgery.

The management of pediatric renovascular hypertension: a single center experience and review of the literature.

Introduction: Renal artery occlusive disease is poorly characterized in children; treatments include medications, endovascular techniques, and surgery. We aimed to describe the course of renovascular hypertension (RVH), its treatments and outcomes.

Methods: We performed literature review and retrospective review (1993-2014) of children with renovascular hypertension at our institution.

CT-guided localization of pulmonary nodules in children prior to video-assisted thoracoscopic surgical resection utilizing a combination of two previously described techniques.

Background: Pulmonary nodules in pediatric oncology patients can present a diagnostic and treatment dilemma. Imaging findings are often nonspecific and tissue diagnosis may be required for appropriate treatment. The smaller subpleural nodules may not be visualized and cannot be palpated during video-assisted thoracoscopic surgical (VATS) resection.

Intratumoral Injection of HSV1716, an Oncolytic Herpes Virus, Is Safe and Shows Evidence of Immune Response and Viral Replication in Young Cancer Patients.

HSV1716 is an oncolytic herpes simplex virus-1 (HSV-1) studied in adults via injection into the brain and superficial tumors. To determine the safety of administering HSV1716 to pediatric patients with cancer, we conducted a phase I trial of image-guided injection in young patients with relapsed or refractory extracranial cancers. We delivered a single dose of 10 to 10 infectious units of HSV1716 via computed tomography-guided intratumoral injection and measured tumor responses by imaging.

Comparison of complications between pediatric peripherally inserted central catheter placement techniques.

Background: Peripherally inserted central catheter (PICC) is among the most common procedures performed in children in the hospital setting. PICC insertion can be simplified with the use of a sheathed needle as an alternative to the modified Seldinger technique.

Objective: To retrospectively evaluate PICC placement for the technique used and the incidence of complications at a large pediatric tertiary care center.

Augmented Reality on a C-Arm System: A Preclinical Assessment for Percutaneous Needle Localization.

Purpose To compare the navigational accuracy and radiation dose during needle localization of targets for augmented reality (AR) with and without motion compensation (MC) versus those for cone-beam computed tomography (CT) with real-time fluoroscopy navigation in a pig model. Materials and Methods This study was approved by the Institutional Animal Care and Use Committee. Three operators each localized 15 targets (bone fragments) approximately 7 cm deep in the paraspinal muscles of nine Yorkshire pigs by using each of the three modalities (AR with and without MC and cone-beam CT with fluoroscopy).

Ultrasound-Guided Botulinum Toxin Type A Salivary Gland Injection in Children for Refractory Sialorrhea: 10-Year Experience at a Large Tertiary Children's Hospital.

Background: Sialorrhea is problematic for neurologically impaired children, and botulinum toxin A salivary gland injection has been reported as effective in reducing sialorrhea. This article assesses the success and safety of ultrasound-guided weight-based botulinum toxin A injection for the management of sialorrhea in children.

Methods: A total of 111 patients (63 males; 48 females; average age 7 years) with refractory sialorrhea were treated with ultrasound-guided botulinum toxin type A salivary gland injections (144 procedures) from July 1, 2004, to July 1, 2014, using a single weight-based protocol.

Comparison of pediatric radiation dose and vessel visibility on angiographic systems using piglets as a surrogate: antiscatter grid removal vs. lower detector air kerma settings with a grid - a preclinical investigation.

The purpose of this study was to reduce pediatric doses while maintaining or improv-ing image quality scores without removing the grid from X-ray beam. This study was approved by the Institutional Animal Care and Use Committee. Three piglets (5, 14, and 20 kg) were imaged using six different selectable detector air kerma (Kair) per frame values (100%, 70%, 50%, 35%, 25%, 17.

Use of cone-beam CT and live 3-D needle guidance to facilitate percutaneous nephrostomy and nephrolithotripsy access in children and adolescents.

Background: Gaining access into non-dilated renal collecting systems for percutaneous nephrolithotripsy, particularly in patients with prohibitive body habitus and/or scoliosis, is often challenging using conventional techniques.

Objective: To evaluate the feasibility of cone-beam CT for percutaneous nephrostomy placement for subsequent percutaneous nephrolithotripsy in children and adolescents.

Materials And Methods: A retrospective review of percutaneous nephrostomy revealed use of cone-beam CT and 3-D guidance in 12 percutaneous nephrostomy procedures for 9 patients between 2006 and 2015.

Isolated Upper Extremity Posttransplant Lymphoproliferative Disorder in a Child.

Posttransplant lymphoproliferative disorder (PTLD) is a well-described complication of solid organ and bone marrow transplants. The most common presentation is intra-abdominal lymphadenopathy or single or multiple intraparenchymal masses involving the liver, spleen, or kidneys. Here we describe the imaging and pathology findings of an unusual case of PTLD appearing as an intramuscular forearm lesion in a pediatric male.

Estimates of diagnostic reference levels for pediatric peripheral and abdominal fluoroscopically guided procedures.

Objective: The objective of our study was to survey radiation dose indexes of pediatric peripheral and abdominal fluoroscopically guided procedures from which estimates of diagnostic reference levels (DRLs) can be proposed for both a standard fluoroscope and a novel fluoroscope with advanced image processing and lower radiation dose rates.

Materials And Methods: Radiation dose structured reports were retrospectively collected for 408 clinical pediatric cases: Half of the procedures were performed with a standard imaging technology and half with a novel x-ray technology. Dose-area product (DAP), air Kerma (AK), fluoroscopy time, number of digital subtraction angiography images, and patient mass were collected to calculate and normalize radiation dose indexes for procedures completed with the standard and novel fluoroscopes.

Endovascular thrombolysis to salvage central venous access in children with catheter-associated upper extremity deep vein thrombosis: technique and initial results.

Nine patients (average age 8.3 years, range 20 days to 17 years; average weight 31 kg, range 2.7-79 kg) with catheter-associated UE-DVT underwent upper extremity venous thrombolysis with the goal of access salvage.

Real-Time In Vivo Characterization of Primary Liver Tumors With Diffuse Optical Spectroscopy During Percutaneous Needle Interventions: Feasibility Study in Woodchucks.

Objective: This study presents the first in vivo real-time optical tissue characterization during image-guided percutaneous intervention using near-infrared diffuse optical spectroscopy sensing at the tip of a needle. The goal of this study was to indicate transition boundaries from healthy tissue to tumors, namely, hepatic carcinoma, based on the real-time feedback derived from the optical measurements.

Materials And Methods: Five woodchucks with hepatic carcinoma were used for this study.

Phase 1 study of intratumoral Pexa-Vec (JX-594), an oncolytic and immunotherapeutic vaccinia virus, in pediatric cancer patients.

Pexa-Vec (pexastimogene devacirepvec, JX-594) is an oncolytic and immunotherapeutic vaccinia virus designed to destroy cancer cells through viral lysis and induction of granulocyte-macrophage colony-stimulating factor (GM-CSF)-driven tumor-specific immunity. Pexa-Vec has undergone phase 1 and 2 testing alone and in combination with other therapies in adult patients, via both intratumoral and intravenous administration routes. We sought to determine the safety of intratumoral administration in pediatric patients.

Ultrasound-guided interventions in children.

There are a variety of available imaging modalities used for minimally invasive procedures in children, however, among the most frequently used is ultrasound (US). The advantages of US are vast and include real-time visualization, lack of ionizing radiation, and all-around versatility. US is also inexpensive, portable and widely available.

Endovascular venous thrombolysis in children younger than 24 months.

Purpose: To evaluate the technical feasibility and safety of percutaneous endovascular thrombolysis for extremity deep venous thrombosis (DVT) in children < 24 months old.

Materials And Methods: A retrospective chart review of a clinical and imaging database was performed for pediatric patients who underwent endovascular therapy for DVT between January 2010 and July 2013. Indications, techniques, technical and clinical success, and complications were reviewed.

Clinically useful dilution factors for iodine and gadolinium contrast material: an animal model of pediatric digital subtraction angiography using state-of-the-art flat-panel detectors.

Background: Iodinated and gadolinium contrast agents pose some risk for certain pediatric patients, including allergic-like reactions, contrast-induced nephropathy (CIN) and nephrogenic systemic fibrosis (NSF). Digital flat-panel detectors enhance image quality during angiography and might allow use of more dilute contrast material to decrease risk of complications that might be dose-dependent, such as CIN and NSF.

Objective: To assess the maximum dilution factors for iodine- and gadolinium-based contrast agents suitable for vascular imaging with fluoroscopy and digital subtraction angiography (DSA) on digital flat-panel detectors in an animal model.

Extended composite temporoparietal fascial flap: clinical implications for tissue engineering in mandibular reconstruction.

Background: The authors have expanded upon a well-described and widely used flap in the head and neck region. The purpose of the cadaver study was to determine the feasibility, angiosome, and the potential application of this pedicled flap in bone tissue engineering of the mandible.

Methods: A total of 6 fresh human cadaver heads were dissected for a total of 12 flaps.

Varicocele retrograde embolization with boiling contrast medium and gelatin sponges in adolescent subjects: a clinically effective therapeutic alternative.

Purpose: Varicoceles occur in approximately 15% of adolescent male subjects and may impair future fertility. The present study describes a varicocele treatment technique involving percutaneous retrograde embolization with boiling hot contrast medium and gelatin sponge pledgets.

Materials And Methods: A retrospective review of medical records and imaging of all patients who underwent percutaneous retrograde varicocele embolization from 2005 to 2010 was performed.