Macrophage ablation significantly reduces uptake of imaging probe into organs of the reticuloendothelial system.

Background: Macrophages engulf particulate contrast media, which is pivotal for biomedical imaging.

Purpose: To introduce a macrophage ablation animal model by showing its power to manipulate the kinetics of imaging probes.

Material And Methods: The kinetics of a particulate computed tomography (CT) contrast media was compared in macrophage ablative mice and normal mice.

Radiation exposure of the interventional radiologist during percutaneous biopsy using a multiaxis interventional C-arm CT system with 3D laser guidance: a phantom study.

Objective: Evaluation of absolute radiation exposure values for interventional radiologists (IRs) using a multiaxis interventional flat-panel C-arm cone beam CT (CBCT) system with three-dimensional laser guidance for biopsy in a triple-modality, abdominal phantom.

Methods: In the phantom, eight lesions were punctured in two different angles (in- and out-of-plane) using CBCT. One C-arm CT scan was performed to plan the intervention and one for post-procedural evaluation.

Synthesis and characterization of Bi2O3/HSA core-shell nanoparticles for X-ray imaging applications.

Bismuth oxide nanoparticles of 12.1 ± 3.0 nm diameter were prepared by thermal decomposition of bismuth acetate dissolved in ethylene glycol in the presence of an oxidizing agent.

Expansion of the Multi-Link Frontier™ coronary bifurcation stent: micro-computed tomographic assessment in human autopsy and porcine heart samples.

Background: Treatment of coronary bifurcation lesions remains challenging, beyond the introduction of drug eluting stents. Dedicated stent systems are available to improve the technical approach to the treatment of these lesions. However dedicated stent systems have so far not reduced the incidence of stent restenosis.

First multimodal embolization particles visible on x-ray/computed tomography and magnetic resonance imaging.

Objectives: Embolization therapy is gaining importance in the treatment of malignant lesions, and even more in benign lesions. Current embolization materials are not visible in imaging modalities. However, it is assumed that directly visible embolization material may provide several advantages over current embolization agents, ranging from particle shunt and reflux prevention to improved therapy control and follow-up assessment.

Cochlear osteoneogenesis after meningitis in cochlear implant patients: a retrospective analysis.

Study Design: Retrospective clinical study.

Setting: Academic tertiary referral center at the Medical University of Hannover.

Patients: Computed tomographic findings of 126 patients (95 children and 31 adults) profoundly deafened by meningitis during a period of 20 years were evaluated.

Synthesis and characterization of dual modality (CT/MRI) core-shell microparticles for embolization purposes.

Core P(MAOETIB-GMA) microparticles of 40-200 microm were prepared by suspension copolymerization of the iodinated monomer 2-methacryloyloxyethyl (2,3,5-triiodobenzoate), MAOETIB, with a low concentration of the monomer glycidyl methacrylate, GMA, which formed hydrophilic surfaces on the particles. Magnetic gamma-Fe(2)O(3)/P(MAOETIB-GMA) core-shell microparticles were prepared by coating the aforementioned core particles through nucleation of iron oxide nanoparticles on the surfaces of the P(MAOETIB-GMA) particles. This was followed by stepwise growth of thin iron oxide layers.

Intrarenal artery delineation with ultra high resolution, flat panel based, volume computerized tomography: outer limits of spatial resolution.

Purpose: New methods of noninvasive high resolution imaging may improve the delineation of tumor microvessels and, thus, be of significant help in surgical planning and cost-effective monitoring of novel anti-angiogenic therapy. We determined the maximum delineation of intrarenal microvessels with a novel flat panel based volume computerized tomography system in an experimental setting.

Materials And Methods: We prospectively evaluated 13 porcine renal specimens for intrarenal vessel delineation using a prototype gantry based, flat panel, cone beam computerized tomography system.

Intrinsic gating for small-animal computed tomography: a robust ECG-less paradigm for deriving cardiac phase information and functional imaging.

Background: A projection-based method of intrinsic cardiac gating in small-animal computed tomography imaging is presented.

Methods And Results: In this method, which operates without external ECG monitoring, the gating reference signal is derived from the raw data of the computed tomography projections. After filtering, the derived gating reference signal is used to rearrange the projection images retrospectively into data sets representing different time points in the cardiac cycle during expiration.

Gating in small-animal cardio-thoracic CT.

Gating is necessary in cardio-thoracic small-animal imaging because of the physiological motions that are present during scanning. In small-animal computed tomography (CT), gating is mainly performed on a projection base because full scans take much longer than the motion cycle. This paper presents and discusses various gating concepts of small-animal CT, and provides examples of concrete implementation.

Dynamic imaging of a model of intracranial saccular aneurysms using ultra-high-resolution flat-panel volumetric computed tomography. Laboratory investigation.

Object: Imaging of intracranial aneurysms using conventional multidetector CT (MDCT) is limited because of nonvisualization of features such as perforating vessels, pulsatile blebs, and neck remnants after clip placement or coil embolization. In this study, a model of intracranial saccular aneurysms in rabbits was used to assess the ultra-high resolution and dynamic scanning capabilities of a prototype flat-panel volumetric CT (fpVCT) scanner in demonstrating these features.

Methods: Ten New Zealand white rabbits underwent imaging before and after clipping or coil embolization of surgically created aneurysms in the proximal right carotid artery.

Flat-panel volume CT: fundamental principles, technology, and applications.

Flat-panel volume computed tomography (CT) systems have an innovative design that allows coverage of a large volume per rotation, fluoroscopic and dynamic imaging, and high spatial resolution that permits visualization of complex human anatomy such as fine temporal bone structures and trabecular bone architecture. In simple terms, flat-panel volume CT scanners can be thought of as conventional multidetector CT scanners in which the detector rows have been replaced by an area detector. The flat-panel detector has wide z-axis coverage that enables imaging of entire organs in one axial acquisition.

Musculoskeletal applications of flat-panel volume CT.

Flat-panel volume computed tomography (fpVCT) is a recent development in imaging. We discuss some of the musculoskeletal applications of a high-resolution flat-panel CT scanner. FpVCT has four main advantages over conventional multidetector computed tomography (MDCT): high-resolution imaging; volumetric coverage; dynamic imaging; omni-scanning.

Intrinsic respiratory gating in small-animal CT.

Gating in small-animal CT imaging can compensate artefacts caused by physiological motion during scanning. However, all published gating approaches for small animals rely on additional hardware to derive the gating signals. In contrast, in this study a novel method of intrinsic respiratory gating of rodents was developed and tested for mice (n=5), rats (n=5) and rabbits (n=2) in a flat-panel cone-beam CT system.

Retrospective motion gating in small animal CT of mice and rats.

Objectives: Implementation and evaluation of retrospective respiratory and cardiac gating of mice and rats using a flat-panel volume-CT prototype (fpVCT).

Materials And Methods: Respiratory and cardiac gating was implemented by equipping a fpVCT with a small animal monitoring unit. ECG and breathing excursions were recorded and 2 binary gating signals derived.

A true minimally invasive approach for cochlear implantation: high accuracy in cranial base navigation through flat-panel-based volume computed tomography.

Objective: High-precision intraoperative navigation using high-resolution flat-panel volume computed tomography makes feasible the possibility of minimally invasive cochlear implant surgery, including cochleostomy. Conventional cochlear implant surgery is typically performed via mastoidectomy with facial recess to identify and avoid damage to vital anatomic landmarks. To accomplish this procedure via a minimally invasive approach--without performing mastoidectomy--in a precise fashion, image-guided technology is necessary.

Placement of intraventricular catheters using flexible electromagnetic navigation and a dynamic reference frame: a new technique.

Background: Catheterization of narrow ventricles may prove difficult resulting in misplacement or inefficient trials with potential damage to brain tissue.

Material And Methods: The application of a new module for navigated ventricular catheterization using flexible electromagnetic navigation and a dynamic reference frame is presented.

Results: Navigated catheter placement was successful and accurate in a pilot study.

Increase of accuracy in intraoperative navigation through high-resolution flat-panel volume computed tomography: experimental comparison with multislice computed tomography-based navigation.

Hypothesis: High-resolution imaging, as provided by flat-panel-based volume computed tomography (fpVCT), could increase navigation accuracy and could therefore improve image-guided procedures or make novel navigated surgery concepts possible.

Background: Intraoperative navigation is an accepted tool in head and neck surgery. However, its use is limited in the lateral cranial base because of its low surgical accuracy.

Flat-panel volume computed tomography for cochlear implant electrode array examination in isolated temporal bone specimens.

Hypothesis: Flat-panel based volume computed tomography could improve cochlear implant electrode evaluation in comparison with multislice computed tomography.

Background: Flat-panel based volume computed tomography offers higher spatial resolution and less metal artifacts than multislice computed tomography. Both characteristics could improve the evaluation of challenging but important questions in cochlear implantation assessment, such as an exact imaging of cochlea, osseous spiral lamina, electrode array position, and single electrode contacts.

High-resolution computed tomography of temporal bone: Part IV: Coronal postoperative anatomy.

The purpose of this 4-part series is to illustrate the nuances of temporal bone anatomy using a high-resolution (200 micro isotropic) prototype volume computed tomography (CT) scanner. The normal anatomy in axial and coronal sections is depicted in the first and second parts. In this, the fourth part, and the third part, the structures that are removed and/or altered in 9 different surgical procedures are color coded and inscribed in the same coronal (article IV) and axial (article III) sections.

High-resolution computed tomography of temporal bone: Part III: Axial postoperative anatomy.

The purpose of this 4-part series is to illustrate the nuances of temporal bone anatomy using a high-resolution (200-mu isotropic) prototype volume computed tomography (CT) scanner. The normal anatomy in axial and coronal sections is depicted in the first and second parts. In this and the subsequent part, the structures that are removed and/or altered in 9 different surgical procedures are color coded and inscribed in the same axial (article III) and coronal (article IV) sections.

Ultra-high resolution flat-panel volume CT: fundamental principles, design architecture, and system characterization.

Digital flat-panel-based volume CT (VCT) represents a unique design capable of ultra-high spatial resolution, direct volumetric imaging, and dynamic CT scanning. This innovation, when fully developed, has the promise of opening a unique window on human anatomy and physiology. For example, the volumetric coverage offered by this technology enables us to observe the perfusion of an entire organ, such as the brain, liver, or kidney, tomographically (e.

High-resolution computed tomography of temporal bone: Part II: coronal preoperative anatomy.

The purpose of this 4-part series is to demonstrate the high-resolution axial and coronal anatomy of temporal bone from a flat-panel detector-based volume computed tomography (CT) scanner (parts I and II); these imaging planes are then used to outline the effect of different surgical procedures commonly applied to the temporal bone (parts III and IV). The structures that are removed and/or altered in 11 different surgical procedures are color coded and inscribed in axial and coronal sections. Clinically important imaging features and complications after these operations are also discussed.

High-resolution flat-panel volume-CT of temporal bone--part 1: axial preoperative anatomy.

The purpose of this four-part series is to show the high-resolution axial and coronal anatomy of the temporal bone from a flat-panel detector-based volume CT (parts 1 and 2); these imaging planes are then used to outline the effect of different surgical procedures commonly applied to the temporal bone (parts 3 and 4). The structures that are removed or altered in 11 different surgical procedures are color-coded and inscribed in axial and coronal sections. Clinically important imaging features and complications following these surgeries will also be discussed.