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Andreas Saleh

Publications and source records attributed to Andreas Saleh.

12 recordsLinked to original sources
PubMed2006

Wilson's disease tremor is associated with magnetic resonance imaging lesions in basal ganglia structures.

Wilson's disease (WD) is an inherited disorder of copper metabolism yielding marked motor deficits, including a severely disabling tremor. As a structural correlate of the disease, a variety of cerebral abnormalities has been revealed. However, the relationship between motor deficits and cerebral lesions has remained largely unknown. Here, we investigated correlation between WD tremor and cerebral magnetic resonance imaging (MRI) findings. Cerebral MRI abnormalities in 6 symptomatic WD patients were compared to findings in 6 asymptomatic WD patients and 10 healthy controls. All patients were treated with long-term copper chelating therapy. Motor symptoms including tremor were determined by Unified Parkinson's Disease Rating Scale Part III (UPDRS-III). MRI findings in symptomatic WD patients revealed significant symmetric T2*-weighted hypointense signal alterations of globus pallidus, head of the caudate nucleus, and substantia nigra. In contrast, MRI of asymptomatic WD patients did not differ from healthy controls. Correlation analysis revealed a significant positive correlation between MRI basal ganglia lesions and UPDRS action tremor score. Our results demonstrate for the first time that Wilson's disease tremor is associated with lesions of the globus pallidus, the head of the caudate nucleus, and the substantia nigra.

Adult↗
PubMed2005

Clinical stabilization and effective B-lymphocyte depletion in the cerebrospinal fluid and peripheral blood of a patient with fulminant relapsing-remitting multiple sclerosis.

BACKGROUND: The anti-CD20 monoclonal antibody rituximab effectively depletes B lymphocytes and has been successfully used in the therapy of immune-mediated disorders of the peripheral nervous system. A limited effect of rituximab on B lymphocytes in the cerebrospinal fluid compartment of patients with primary progressive multiple sclerosis (MS) was recently reported. OBJECTIVE: To determine the effect of rituximab on clinical, magnetic resonance imaging, and immunological variables in a patient with relapsing-remitting MS. DESIGN: A patient with relapsing-remitting MS was treated with rituximab. The patient was repeatedly examined clinically and by magnetic resonance imaging. The frequency of peripheral blood and cerebrospinal fluid B lymphocytes was assessed by flow cytometry before, during, and after rituximab therapy. RESULTS: Rituximab monotherapy resulted in significant clinical improvement. Inflammatory surrogate markers on magnetic resonance imaging were also reduced. B lymphocytes were depleted in the cerebrospinal fluid and peripheral blood. CONCLUSIONS: Our data demonstrate beneficial clinical effects of rituximab in relapsing-remitting MS, mediated through modulation of humoral systemic and central nervous system intrinsic immune responses. Clinical trials should determine optimal therapeutic strategies for patients with relapsing-remitting MS.

Adult↗
PubMed2004

Coverage of anterior fossa in whole-brain irradiation.

PURPOSE: Whole-brain irradiation is indispensable in the treatment of several brain tumors and requires coverage of the entire subarachnoid space. Retrospective studies have revealed frequent recurrences in the frontobasal fossa above the cribriform plate (CP). We sought to determine how accurately the latter could actually be identified on lateral radiographs such as those used for radiotherapy planning. METHODS AND MATERIALS: The CP was localized by five radiation oncologists and five radiologists on lateral radiographs of 30 human skulls from an anatomic collection. Reference radiographs were acquired under identical conditions except for lead markers pointing to the CP and the ethmoid cells. The targeting accuracy was analyzed. RESULTS: In 39% (n = 116), the location of the CP was correctly estimated within 2 mm. Mislocations of 2-5, 5-10, and >10 mm were noted in 34% (n = 102), 20% (n = 61), and 7% (n = 21), respectively. Neither specialty nor experience (years of training) exerted a significant influence on targeting accuracy. If the roofs of the ethmoid cells formed prominent bony edges, they were mistaken for the CP in 37%. CONCLUSION: Lateral radiographs provide insufficient information to locate the CP accurately in whole brain irradiation. Additionally, localization was significantly impaired by prominent ethmoid cells.

Adult↗
PubMed2004

In vivo MRI of brain inflammation in human ischaemic stroke.

Inflammation contributes to brain damage caused by ischaemic stroke. Macrophages, as the prevailing inflammatory cell population in stroke lesions, can be visualized using ultrasmall superparamagnetic iron oxide (USPIO) as a cell-specific contrast agent for MRI. In this single-centre open-labelled clinical phase II study we tested the potential of USPIO-enhanced MRI for macrophage imaging in human ischaemic stroke lesions. In a series of 10 consecutive patients, USPIO contrast agent was infused at the end of the first week after symptom onset. Two follow-up MRI scans were performed 24-36 h and 48-72 h after infusion. Two distinct components of USPIO-related signal changes were discernible, one associated with blood vessels and one representing parenchymal enhancement. Vessel-associated changes appeared as signal loss on T2/T2*-weighted images and decreased from the first to second scan after USPIO infusion, most likely reflecting a transient blood pool effect of the contrast agent. Conversely, parenchymal enhancement was mainly evident on T1-weighted images, increased over time, and matched with the expected distribution of macrophages. Importantly, USPIO-induced signal alterations throughout differed from signatures of conventional gadolinium-enhanced MRI, thus being independent from breakdown of the blood-brain barrier. We suggest that increasing USPIO-enhancement on T1-weighted images indicates brain infiltration by USPIO-laden macrophages. Thus, USPIO-enhanced MRI may provide an in vivo surrogate marker of cellular inflammation in stroke and other CNS pathologies.

Aged↗
PubMed2004

Histochemical detection of ultrasmall superparamagnetic iron oxide (USPIO) contrast medium uptake in experimental brain ischemia.

Recently, macrophage infiltration in different central nervous system (CNS) pathologies has been visualized with ultrasmall particles of iron oxide (USPIO) as a new cell-specific contrast medium for MRI. However, validation of these findings at the histological level has been hampered by the fact that the in situ detection of iron uptake by conventional Prussian blue staining is not sensitive enough to detect low amounts of iron in the brain. Here, an improved method for the histochemical detection of USPIO uptake in ischemic brain lesions is reported. The procedure relies on the sequential enhancement of Prussian blue staining by diaminobenzidine and silver/gold impregnation. After photothrombotic cortical brain infarction, this method allowed sensitive in situ detection of iron-laden macrophages which matched both macrophage immunostaining and USPIO-induced signal alterations in high-resolution 7 T MRI. This staining method provides a basis for correlative histological assessment of USPIO-enhanced MRI in a broad spectrum of CNS pathologies.

Animals↗
PubMed2004

Central nervous system inflammatory response after cerebral infarction as detected by magnetic resonance imaging.

Brain inflammation contributes to the tissue injury caused by ischemic stroke. Macrophages as the most abundant inflammatory cell population in stroke lesions can be visualized using ultrasmall superparamagnetic iron oxide (USPIO) as a cell-specific contrast agent for magnetic resonance imaging (MRI). The aim of our present study was to delineate the inflammatory response during experimental cerebral infarction by means of USPIO-enhanced MRI and to correlate the spatial distribution of USPIO-induced MR signal alterations with cellular infiltration and iron deposition. To this end USPIOs were administered to Wistar rats 5 days after photothrombotic cerebral infarction. MR imaging at 7 T performed 24 h later displayed a rim-like signal loss around the infarction in the USPIO treated animals. On histological brain sections obtained from the same animals after MRI the distribution of iron and ED1+ phagocytes was in full spatial agreement with the signal loss seen on T2*-weighted images. Our study validates USPIO-enhanced MRI as an important tool for the noninvasive visualization of brain inflammation in stroke and other CNS pathologies.

Animals↗
PubMed2004

Macrophage imaging in central nervous system and in carotid atherosclerotic plaque using ultrasmall superparamagnetic iron oxide in magnetic resonance imaging.

The long blood circulating time and the progressive macrophage uptake in inflammatory tissues of ultrasmall superparamagnetic iron oxide (USPIO) particles are 2 properties of major importance for magnetic resonance imaging (MRI) pathologic tissue characterization. This article reviews the proof of principle of applications such as imaging of carotid atherosclerotic plaque, stroke, brain tumor characterization, or multiple sclerosis. In the human carotid artery, USPIO accumulation in activated macrophages induced a focal drop in signal intensity compared with preinfusion MRI. The USPIO signal alterations observed in ischemic areas of stroke patients is probably related to the visualization of inflammatory macrophage recruitment into human brain infarction since animal experiments in such models demonstrated the internalization of USPIO into the macrophages localized in these areas. In brain tumors, USPIO particles which do not pass the ruptured blood-brain barrier at early times postinjection can be used to assess tumoral microvascular heterogeneity. Twenty-four hours after injection, when the cellular phase of USPIO takes place, the USPIO tumoral contrast enhancement was higher in high-grade than in low-grade tumors. Several experimental studies and a pilot multiple sclerosis clinical trial in 10 patients have shown that USPIO contrast agents can reveal the presence of inflammatory multiple sclerosis lesions. The enhancement with USPIO does not completely overlap with the gadolinium chelate enhancement. While the proof of concept that USPIO can visualize macrophage infiltrations has been confirmed in animals and patients in several applications (carotid atherosclerotic lesions, stroke, brain tumors and multiple sclerosis), larger prospective clinical studies are needed to demonstrate the clinical benefit of using USPIO as an MRI in vivo surrogate marker for brain inflammatory diseases.

Arteriosclerosis↗
PubMed2003

Improvement of sonographic needle visibility in cirrhotic livers during transjugular intrahepatic portosystemic stent-shunt procedures with use of real-time compound imaging.

The visibility of a transjugular intrahepatic portosystemic stent-shunt (TIPS) puncture needle was assessed with use of real-time compound imaging and single-line ultrasonography (US). In vitro and in vivo, needle-tissue contrast was calculated. With an increasing angle of incidence, the decrease in needle visibility was more pronounced for single-line US than for compound imaging. At angles of incidence of more than 30 degrees, the needle was barely visible with either technique. Subjective evaluation during TIPS procedures in 10 patients proved that the needle tip was significantly better seen with compound imaging. Therefore, real-time compound imaging significantly improved contrast and subjective visibility of the needle.

Adult↗
PubMed2002

Effective doses in standard protocols for multi-slice CT scanning.

The purpose of this study was to assess the radiation exposure of patients in several standard protocols in multi-slice CT (MSCT). Scanning protocols for neck, chest, abdomen, and spine were examined on a Somatom Plus 4 Volume Zoom MSCT (Siemens, Erlangen, Germany) with changing slice collimation (4x1, 4x2.5, and 4x5 mm), and pitch factors (1, 1.5, and 2). Effective doses were calculated from LiF-TLD measurements at several organ sites using an Alderson-Rando phantom and compared with calculations using the weighted CTDI. Effective dose for MSCT of the neck was 2.8 mSv. For different protocols for MSCT of the chest, 7.5-12.9 mSv were found. In abdominal MSCT protocols, effective dose varied between 12.4 and 16.1 mSv. The MSCT of the spine may lead to 12 mSv. An excellent correlation between the effective dose as determined by LiF-TLD and the calculated effective dose using the weighted CTDI could be demonstrated; however, a difference of up to 30% (mean 14.3%) was noted. Standard protocols for MSCT as measured in this study showed effective doses of up to16 mSv. Phantom measurement data show a good correlation to estimations using the weighted CTDI.

Abdomen↗
PubMed2002

A seropneumothorax?

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Diagnosis, Differential↗