Determining the Rotational Orientation of Directional Deep Brain Stimulation Leads Employing Flat-Panel Computed Tomography.

Background: Directional deep brain stimulation (DBS) constitutes an emerging technology that allows selective stimulation of target structures via partitioned electrode contacts. In order to effectively perform target-tailored stimulation, knowledge of the rotational orientation of the segmented leads is imperative.

Objective: To develop a universally applicable and reliable method for determination of lead orientation angles in DBS using flat-panel computed tomography (fpCT).

Intensity-based 2D 3D registration for lead localization in robot guided deep brain stimulation.

Intraoperative assessment of lead localization has become a standard procedure during deep brain stimulation surgery in many centers, allowing immediate verification of targeting accuracy and, if necessary, adjustment of the trajectory. The most suitable imaging modality to determine lead positioning, however, remains controversially discussed. Current approaches entail the implementation of computed tomography and magnetic resonance imaging.

Tractography-guided stimulation of somatosensory fibers for thalamic pain relief.

Background: The spinothalamocortical tract (STC) is seen as a neural tract responsible for or involved in the generation or transmission of thalamic pain. Either the thalamus itself or the posterior limb of the internal capsule (PLIC) are targets for deep brain stimulation (DBS) in patients with thalamic pain, but due to its low contrast, conventional MRI cannot visualize the STC directly.

Objectives: To show the feasibility of integrating diffusion tensor imaging-based tractography into the stereotactic treatment planning for identification of an object-oriented lead trajectory that allows STC-DBS with multiple electrode contacts.

Accuracy and reproducibility of a novel semi-automatic segmentation technique for MR volumetry of the pituitary gland.

Introduction: Although several reports about volumetric determination of the pituitary gland exist, volumetries have been solely performed by indirect measurements or manual tracing on the gland's boundaries. The purpose of this study was to evaluate the accuracy and reproducibility of a novel semi-automatic MR-based segmentation technique.

Methods: In an initial technical investigation, T1-weighted 3D native magnetised prepared rapid gradient echo sequences (1.

Multimodal localization of electrodes in deep brain stimulation: comparison of stereotactic CT and MRI with teleradiography.

Objective: In cross-sectional imaging, like CT or MRI, electrodes for deep brain stimulation are visualized by an artifact, which can differ from the real physical size of the electrode and even have an asymmetric appearance on MRI. The accuracy of such artifact-based estimation of the real position of the electrode using CT or MRI is investigated here. Stereotactic teleradiography was used as the gold standard.

Intraoperative X-ray detection and MRI-based quantification of brain shift effects subsequent to implantation of the first electrode in bilateral implantation of deep brain stimulation electrodes.

Objective: After implantation of the first electrode in bilateral deep brain stimulation (DBS) lead implantation, brain shift effects in the target region and along the implantation trajectory of the second electrode are quantified with intraoperative magnetic resonance imaging (MRI). We investigated intraoperative X-ray imaging for its feasibility in indirect detection of brain shift.

Methods: In 25 patients who underwent bilateral DBS lead implantation, X-ray and MRI were performed before and after implantation of the first electrode.

Cross-sectional study on bone density-related sonographic parameters in children with asthma: correlation to therapy with inhaled corticosteroids and disease severity.

The aim of this study was to screen asthmatic children for bone density-related sonographic parameters on the calcaneal bone. Findings were correlated to therapy with inhaled corticosteroids (ICS) as well as with asthma severity (AS), concomitance and severity of atopic dermatitis (AD), and rhinitis (AR). We enrolled 173 children with AS1-3 consecutively; 44% (AS1) had not received any ICS medication; 56% (AS2 and -3) received ICS therapy for > or =6 months (medium daily dose, 286 microg fluticasone-proprionate-equivalent/maximum 500 microg); and in addition 38% (n = 65) presented with AD and 66% (n = 115) with AR.

Intracranial aneurysms: role of multidetector CT angiography in diagnosis and endovascular therapy planning.

Purpose: To evaluate the sensitivity of 16-detector row computed tomographic (CT) angiography in diagnosis of intracranial aneurysms and to determine whether multidetector CT angiography provides sufficient diagnostic information to guide endovascular treatment, with combined imaging and clinical data as the reference standard.

Materials And Methods: Institutional review board approval and informed consent were obtained. Eighty-seven patients clinically suspected of having subarachnoid hemorrhage underwent multidetector CT angiography and digital subtraction angiography (DSA).

Combined x-ray and magnetic resonance imaging facility: application to image-guided stereotactic and functional neurosurgery.

Objective: To assess the feasibility of a hybrid imaging setup combining x-ray and magnetic resonance imaging (MRI) in the setting of both stereotactic and functional neurosurgery.

Methods: A combined x-ray and MRI scanning facility with a trolley system for a fast patient transfer between both modalities was installed in a neurosurgical setting. A registration algorithm for fusion of MRI scans and x-ray images was derived for augmentation of fluoroscopic x-ray projection images with MRI scan data, such as anatomic structures and planned probe trajectories.

No evidence for a substantial involvement of primary motor hand area in handedness judgements: a transcranial magnetic stimulation study.

Twelve right-handed volunteers were asked to judge the laterality of a hand stimulus by pressing a button with one of their toes. Judgements were based on two-dimensional drawings of the back or palm of a right or left hand at various orientations. Suprathreshold single-pulse transcranial magnetic stimulation (TMS) was given to the left primary motor hand area (M1-HAND) at 0, 200, 400, 600, 800 or 1000 ms after stimulus onset to probe the functional involvement of the dominant left M1 at various stages of handedness recognition.

Autofluorescence spectroscopy in whole organs with a mobile detector system.

Rationale And Objectives: Autofluorescence can be exploited to obtain spectroscopic information about tissues or organs in a noninvasive fashion. The knowledge of normal organ patterns is a prerequisite for subsequent characterization of pathological states, eg, inflammation or tumors. Therefore, the aim of this study was to investigate the autofluorescence properties of healthy organs in mice.

Diagnosis of arthritis using near-infrared fluorochrome Cy5.5.

Purpose: Near-infrared range fluorescence (NIRF) imaging is a potential tool to diagnose biologic processes in vivo. This applicability study sought to define whether imaging with fluorochrome Cy5.5 can identify arthritis in murine antigen-induced arthritis (AIA).

Are unnecessary follow-up procedures induced by computer-aided diagnosis (CAD) in mammography? Comparison of mammographic diagnosis with and without use of CAD.

Objective: To evaluate the rate of unnecessary follow-up procedures recommended by radiologists using a CAD-system.

Materials And Methods: 185 patients (740 images) were consecutively selected from three groups (36 histologically proven cancers = group 1; 49 histologically proven benign lesions = group 2 and 100 screening cases (4 years-follow up = group 3). Mammograms were evaluated by a CAD system (Second Look, CADx, Canada).

Changes in magnetic resonance mammography due to hormone replacement therapy.

Background: The aim of the present article is to investigate effects of hormone replacement therapy (HRT) on contrast medium enhancement patterns in postmenopausal patients during magnetic resonance mammography (MRM).

Materials And Methods: Two hundred and fifteen patients receiving hormonal medication were divided into four groups: 150 patients with 1 MRM during HRT (group A), 13 patients with 2 MRMs under HRT (group B), 30 patients with 1 MRM during HRT and 1 MRM after HRT withdrawal (group C), and 22 women with 1 MRM after HRT withdrawal (group D). Dynamic MRM was performed at 1.

In vivo imaging of experimental arthritis with near-infrared fluorescence.

Objective: To visualize early experimental arthritis with near-infrared fluorescence (NIRF) imaging in a murine model of antigen-induced arthritis (AIA).

Methods: The target of NIRF was the F4/80 antigen present on the surface of macrophages infiltrating the inflamed synovial membrane. Imaging was performed using anti-F4/80 monoclonal antibodies (mAb) labeled with Cy5.

Optimized distortion correction of epi-based statistical parametrical maps for stereotactic neurosurgery.

A new approach is presented for unwarping geometrical distortions in echo planar imaging (EPI)-based statistical parametrical maps (SPM). With the developed method, a substantial reduction of geometrical distortions in the order of 5-15 mm down to a residue of approximately 1-2 mm was possible, thus allowing reliable activation localization and, hence, interpretation after fusion with undistorted conventional anatomic images. The unwarping procedure is an optimized combination of two distortion correction methods, the "inhomogeneity mapping" and the coregistration approach.

Effect of routine MR imaging of the brain at 1.5 T on subsequent magnetoencephalography: results in nine volunteers.

Purpose: To investigate whether routine magnetic resonance (MR) imaging of the brain with a whole-body 1.5-T imager affects the results of subsequent magnetoencephalography (MEG).

Materials And Methods: Nine healthy volunteers (six women, mean age of 23 years, age range of 20-27 years; three men, mean age of 24 years, age range of 23-25 years) underwent one MEG session before and two MEG sessions after MR imaging of the brain.

Noninvasive diagnosis of arthritis by autofluorescence.

Rationale And Objectives: The detection of arthritis by autofluorescence was investigated using an antigen-induced arthritis model.

Methods: For autofluorescence investigations of joints, a mobile fluorescence-detector was constructed consisting of a lens/mirror system attached to a conventional spectrofluorometer and optimized fiber optic cables reaching to and from the site of investigation. Autofluorescence measurements were performed at 7 arthritic and 7 healthy mice.

Influence of breast lesion size and histologic findings on tumor detection rate of a computer-aided detection system.

Purpose: To evaluate associations between histopathologic findings, tumor size, and detection rate of malignant mammographic findings by using a computer-aided detection (CAD) system.

Materials And Methods: The study included 208 mammographically detected histologically proven malignant breast lesions in 208 women. Findings were 150 masses and 114 microcalcifications; 56 lesions showed both findings; 94 lesions, mass only; and 58 lesions, microcalcification only.

Influence of size and depth on accuracy of electrical impedance scanning.

Cancer cells exhibit altered local dielectric properties which can be assessed using electrical impedance scanning (EIS). The study was aimed at clarifying influence of lesion size and depth on EIS performance. From a series of 387 lesions (129 malignant and 258 benign) from 363 patients being sonographically and/or mammographically evaluated, size and depth information was not available in 112 lesions, size was available in 86 lesions and additional depth information was available in 189 lesions, respectively, while performing EIS.

Normative values of bone parameters of children and adolescents using digital computer-assisted radiogrammetry (DXR).

Purpose: To verify whether estimation of bone mineral density (BMD) using digital X-ray radiogrammetry (DXR) is possible on children and to determine normative values of both such a DXR-BMD estimate and a corresponding metacarpal index (DXR-MCI) on.

Patients And Methods: In retrospect, X-rays were selected of the hands of 200 healthy Caucasian children (120 boys and 80 girls, aged 4-18 yr). The involved children were selected among a larger group of children submitted to the surgical department of our institute for evaluation of a suspected fracture after an occurred trauma.

High-frequency transcranial magnetic stimulation of the supplementary motor area reduces bimanual coupling during anti-phase but not in-phase movements.

Previous electrophysiological and neuroimaging studies have provided evidence that the supplementary motor area (SMA) has an important role in the control of bimanual coordination. The present experiment investigated the effects of high-frequency repetitive transcranial magnetic stimulation (rTMS) over the SMA region on kinematic variables during cyclical bimanual coordination, with a particular focus on the quality of coordination. Subjects performed metronome-paced trials of in-phase and anti-phase bimanual index-finger movements at near-maximal cycling frequency.

MR Imaging in Wegener granulomatosis of the spinal cord.

Wegener granulomatosis is a multisystemic disorder characterized by necrotizing vasculitis that primarily involves the respiratory tract. The orbits, heart, skin, joints, and nervous system are frequently involved. We describe the MR imaging findings of Wegener granulomatosis in the cervical spine and correlate them with the histopathologic features.

FAIR and dynamic susceptibility contrast-enhanced perfusion imaging in healthy subjects and stroke patients.

Purpose: To compare dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI) and the flow-sensitive alternating inversion recovery (FAIR) technique for measuring brain perfusion.

Materials And Methods: We investigated 12 patients with acute stroke, and 10 healthy volunteers with FAIR and DSC maps of regional cerebral blood volume (rCBV), mean transit time (MTT), and regional cerebral blood flow (rCBF).

Results: In volunteers good gray/white-matter contrast was observed in FAIR, rCBF, and rCBV maps.