Marc A. Brockmann
Research interests
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InterestsAnimal Physiology, Computational Science
Other
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LanguagesGerman, English
Publications
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3.30Impact points
In Vivo X-Ray Digital Subtraction and CT Angiography of the Murine Cerebrovasculature Using an Intra-Arterial Route of Contrast Injection.
AJNR. American journal of neuroradiology. 05/2012;
BACKGROUND AND PURPOSE:Investigation of the anatomy, patency, and blood flow of arterial and venous vessels in small animal models of cerebral ischemia, venous thrombosis, or vasospasm is of major interest. However, due to their small caliber, in vivo examination of these vessels is technically chal... [more] BACKGROUND AND PURPOSE:Investigation of the anatomy, patency, and blood flow of arterial and venous vessels in small animal models of cerebral ischemia, venous thrombosis, or vasospasm is of major interest. However, due to their small caliber, in vivo examination of these vessels is technically challenging. Using micro-CT, we compared the feasibility of in vivo DSA and CTA of the murine cerebrovasculature using an intra-arterial route of contrast administration.MATERIALS AND METHODS:The ECA was catheterized in 5 C57BL/6J mice. During intra-arterial injection of an iodized contrast agent (30 μL/1 sec), DSA of the intra- and extracranial vessels was performed in mice breathing room air and repeated in hypoxic/hypercapnic mice. Micro-CTA was performed within 20 seconds of intra-arterial contrast injection (220 μL/20 sec). Image quality of both methods was compared. Radiation dose measurements were performed with thermoluminescence dosimeters.RESULTS:Both methods provided high-resolution images of the murine cerebrovasculature, with the smallest identifiable vessel calibers of ≤50 μm. Due to its high temporal resolution of 30 fps, DSA allowed identification of anastomoses between the ICA and ECA by detection of retrograde flow within the superficial temporal artery. Micro-CTA during intra-arterial contrast injection resulted in a reduced injection volume and a higher contrast-to-noise ratio (19.0 ± 1.0) compared with DSA (10.0 ± 1.8) or micro-CTA when using an intravenous injection route (1.3 ± 0.4).CONCLUSIONS:DSA of the murine cerebrovasculature is feasible using micro-CT and allows precise and repeated measurements of the vessel caliber, and changes of the vessel caliber, while providing relevant information on blood flow in vivo.
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Endovascular Repositioning of a Pipeline Embolization Device Dislocated from the Vertebral into the Basilar Artery Using a Stent-in-Stent Technique : Practical and Technical Considerations.
Clinical neuroradiology. 01/2012;
PURPOSE: Stent dislocation is a rarely encountered problem in interventional neuroradiology. This article describes the repositioning of a pipeline embolization device (PED) dislocated from the vertebral artery (VA) into the basilar artery (BA) using a stent-in-stent technique. Based on this case ad... [more] PURPOSE: Stent dislocation is a rarely encountered problem in interventional neuroradiology. This article describes the repositioning of a pipeline embolization device (PED) dislocated from the vertebral artery (VA) into the basilar artery (BA) using a stent-in-stent technique. Based on this case additional in vitro measurements were performed. METHODS: In a patient, a larger PED (4.0 ´ 20 mm) was partially opened in a PED (3.0 ´ 20 mm) floating freely within the distal BA. The microcatheter with the partially opened stent was pulled back hereby pulling back the stent-in-stent construct into the VA. In vitro the maximum tensile force that could be applied to a 3.5 mm and a 4.5 mm PED before dislodgement out of a 3.0 mm PED was determined. Videomorphometric analyses of the stent-in-stent construct were performed while applying traction to the construct. RESULTS: Repositioning of a dislocated PED is feasible using a stent-in-stent technique. Higher dislodgement forces can be applied using a larger PED (4.5 mm, 0.36 N) whereas dislodgement occurred faster using a smaller PED (3.5 mm, 0.26 N). Before dislodgement occurs, elongation and tapering of both stents can be seen. Finally, it was found that incidental extraction of the 4.5 mm PED out of the delivering microcatheter during traction is possible. CONCLUSIONS: Repositioning of a lost PED is feasible using a stent-in-stent technique. Principally, dislodgement force is higher using a larger PED, while in this case care has to be taken to avoid incidental extraction of the second PED out of the microcatheter.
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4.72Impact points
Tumor-platelet interaction in solid tumors.
International journal of cancer. Journal international du cancer. 01/2012;
Elevated platelet counts in patients diagnosed with malignant tumors were first described more than 100 years ago. Today it is well known that in many types of solid tumors, thrombocytosis at the time of diagnosis is associated with shorter survival. From this well-documented clinical correlation be... [more] Elevated platelet counts in patients diagnosed with malignant tumors were first described more than 100 years ago. Today it is well known that in many types of solid tumors, thrombocytosis at the time of diagnosis is associated with shorter survival. From this well-documented clinical correlation between platelet count and prognosis of solid tumors, the following questions arise: (i) Are the increased platelet counts the reason for shortened survival as platelet-secreted cytokines might boost tumor growth and angiogenesis? (ii) Do platelets affect tumor metastasis thereby shortening survival time? or (iii) Are increased platelet counts simply an epiphenomenon of tumor growth with larger tumors resulting in higher platelet counts and shorter survival times? We address these three questions within our review of the current literature to provide a comprehensive overview of the current concepts in tumor-platelet interaction.
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4.41Impact points
Three-dimensional in vivo imaging of the murine liver: a micro-computed tomography-based anatomical study.
PloS one. 01/2012; 7(2):e31179.
Various murine models are currently used to study acute and chronic pathological processes of the liver, and the efficacy of novel therapeutic regimens. The increasing availability of high-resolution small animal imaging modalities presents researchers with the opportunity to precisely identify and ... [more] Various murine models are currently used to study acute and chronic pathological processes of the liver, and the efficacy of novel therapeutic regimens. The increasing availability of high-resolution small animal imaging modalities presents researchers with the opportunity to precisely identify and describe pathological processes of the liver. To meet the demands, the objective of this study was to provide a three-dimensional illustration of the macroscopic anatomical location of the murine liver lobes and hepatic vessels using small animal imaging modalities. We analysed micro-CT images of the murine liver by integrating additional information from the published literature to develop comprehensive illustrations of the macroscopic anatomical features of the murine liver and hepatic vasculature. As a result, we provide updated three-dimensional illustrations of the macroscopic anatomy of the murine liver and hepatic vessels using micro-CT. The information presented here provides researchers working in the field of experimental liver disease with a comprehensive, easily accessable overview of the macroscopic anatomy of the murine liver.
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Comparison of digital subtraction angiography, micro-computed tomography angiography and magnetic resonance angiography in the assessment of the cerebrovascular system in live mice.
Clinical neuroradiology. 11/2011; 22(1):21-8.
Mice are often used as small animal models of brain ischemia, venous thrombosis, or vasospasm. This article aimed at providing an overview of the currently available methodologies for in vivo imaging of the murine cerebrovasculature and comparing the capabilities and limitations of the different met... [more] Mice are often used as small animal models of brain ischemia, venous thrombosis, or vasospasm. This article aimed at providing an overview of the currently available methodologies for in vivo imaging of the murine cerebrovasculature and comparing the capabilities and limitations of the different methods. Micro-computed tomography angiography (CTA) was performed during intra-arterial and intravenous administration of a contrast agent bolus. Digital subtraction angiography (DSA) was performed during intra-arterial administration of contrast agent using the micro-CT scanner. Time-of-flight (ToF) magnetic resonance (MR) angiography was performed using a small animal scanner (9.4 T) equipped with a cryogenic transceive quadrature coil. Datasets were compared for scan time, contrast-to-noise ratio (CNR), temporal and spatial resolution, radiation dose, contrast agent dose and detailed recognition of cerebrovascular structures. Highest spatial resolution was achieved using micro-CTA (16 ´ 16 ´ 16 µm) and DSA (14 ´ 14 µm). Compared to micro-CTA (20-40 s) and ToF-MRA (57 min), DSA provided highest temporal resolutions (30 fps) allowing analyses of the cerebrovascular blood flow. Highest mean CNR was reached using ToF-MRA (50.7 ± 15.0), while CNR of micro-CTA depended on the intra-arterial (19.0 ± 1.0) and intravenous (1.3 ± 0.4) use of agents. The CNR of DSA was 10.0 ± 1.8. The use of dedicated small animal scanners allows cerebrovascular imaging in live animals as small as mice. As each of the methods analyzed has its advantages and limitations, choosing the best suited imaging modality for a defined question is of great importance. By this means the aforementioned methods offer a great potential for future projects in preclinical cerebrovascular research including ischemic stroke or vasospasm.
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TrueFISP of the Pediatric Pineal Gland : Volumetric and Microstructural Analysis.
Clinical neuroradiology. 11/2011; 22(1):69-77.
Although high-resolution 3D-imaging has markedly improved the imaging of the pediatric pineal gland, the prevalences of typical and atypical cysts as well as in vivo volumes are unknown. The purpose of this study was to compare the frequency of typical and atypical cysts using high-resolution 3D-seq... [more] Although high-resolution 3D-imaging has markedly improved the imaging of the pediatric pineal gland, the prevalences of typical and atypical cysts as well as in vivo volumes are unknown. The purpose of this study was to compare the frequency of typical and atypical cysts using high-resolution 3D-sequence true fast imaging with steady state precession (trueFISP) and standard sequences and to directly measure the pineal volume in a large pediatric population. In 54 consecutively examined children (age 0-17 years, mean age 5.4 ± 5.6 years, 44% female, 56% male) the prevalence of typical and atypical cysts (thickened rim, trabeculations, asymmetry) was determined using trueFISP (isotropic, 0.8 mm) and standard sequences, 1.5-T, T1-weighted spin echo (T1-SE), T2-weighted turbo spin echo (T2-TSE) and fluid attenuated inversion recovery (FLAIR). Indistinct findings were noted separately. Volumetry was based on the trueFISP datasets. Solid and cystic compartments were approached separately. The pineal volume was correlated to gender and age. The detected frequency of pineal cysts was higher in trueFISP (57.4%) than in standard sequences (T1-SE 7.4%, T2-TSE 14.8%, and FLAIR 13.0%). In trueFISP 66.3% of the detected cysts were classified as atypical (standard sequences 0%). Indistinct findings were lowest in trueFISP. The mean pineal volume was 94.3 ± 159.1 mm³ and no gender related differences were found. Age and volume showed a moderate correlation (r = 0.382) which was remarkably higher in completely solid glands (r = 0.659). TrueFISP imaging improves the detection of pineal cysts in children. A typical cysts are frequently detected as an incidental finding. Volumetric analysis of the pediatric pineal gland is feasible and reveals enormous variation. Whereas gender effects are negligible, the pineal volume in children is dependant on age.
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1.43Impact points
Maintained functionality of an implantable radiotelemetric blood pressure and heart rate sensor after magnetic resonance imaging in rats.
Physiological measurement. 11/2011; 32(12):1941-51.
Radiotelemetric sensors for in vivo assessment of blood pressure and heart rate are widely used in animal research. MRI with implanted sensors is regarded as contraindicated as transmitter malfunction and injury of the animal may be caused. Moreover, artefacts are expected to compromise image evalua... [more] Radiotelemetric sensors for in vivo assessment of blood pressure and heart rate are widely used in animal research. MRI with implanted sensors is regarded as contraindicated as transmitter malfunction and injury of the animal may be caused. Moreover, artefacts are expected to compromise image evaluation. In vitro, the function of a radiotelemetric sensor (TA11PA-C10, Data Sciences International) after exposure to MRI up to 9.4 T was assessed. The magnetic force of the electromagnetic field on the sensor as well as radiofrequency (RF)-induced sensor heating was analysed. Finally, MRI with an implanted sensor was performed in a rat. Imaging artefacts were analysed at 3.0 and 9.4 T ex vivo and in vivo. Transmitted 24 h blood pressure and heart rate were compared before and after MRI to verify the integrity of the telemetric sensor. The function of the sensor was not altered by MRI up to 9.4 T. The maximum force exerted on the sensor was 273 ± 50 mN. RF-induced heating was ruled out. Artefacts impeded the assessment of the abdomen and thorax in a dead rat, but not of the head and neck. MRI with implanted radiotelemetric sensors is feasible in principal. The tested sensor maintains functionality up to 9.4 T. Artefacts hampered abdominal and throacic imaging in rats, while assessment of the head and neck is possible.
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2.75Impact points
Differential effects of tumor-platelet interaction in vitro and in vivo in glioblastoma.
Journal of neuro-oncology. 03/2011; 105(1):45-56.
An elevated platelet count is considered an independent predictor of short survival in glioblastoma and various other tumor entities. Prothrombotic activity of the tumor microcirculation resulting in platelet activation and release of cytokines from activated platelets has been suggested to play a r... [more] An elevated platelet count is considered an independent predictor of short survival in glioblastoma and various other tumor entities. Prothrombotic activity of the tumor microcirculation resulting in platelet activation and release of cytokines from activated platelets has been suggested to play a role. This study was designed to analyze the effects of platelet-released cytokines on glioblastoma and endothelial cell proliferation and migration in vitro, and the influence of platelet count on glioblastoma growth and angiogenesis in vivo. In cultured human glioblastoma, umbilical cord and cerebral microvascular endothelial cells platelet-released cytokines significantly stimulated proliferation and migration as well as sprouting and formation of capillary-like structures. In vivo, glioblastoma cells were implanted in mice followed by platelet depletion starting 1 or 8 days later. Tumor volume, proliferative index, and vessel density analyzed 14 days after engraftment did not differ between animals with a normal and a low platelet count. Likewise, no effect of platelet depletion over 20 days upon the volume of intracerebrally growing tumors was observed in mice. Additionally, proliferative activity and vessel density determined in tumor samples from patients operated upon glioblastoma did not show any correlation with the patients' preoperative platelet count. Thus, we conclude that distinct proliferation- and chemotaxis-stimulating effects of platelet-derived cytokines can be achieved in vitro, while the platelet count does not exert a major influence on tumor growth and tumor angiogenesis in GBM in vivo.
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2.10Impact points
Double-contrast micro-CT colonoscopy in live mice.
International journal of colorectal disease. 03/2011; 26(6):721-7.
Models of colon cancer in small rodents are of particular interest as they most closely simulate the development and growth of colonic cancer in humans. Micro-computed tomography has been used for detection of polyps in murine models of colon cancer. The study was performed to evaluate whether a nov... [more] Models of colon cancer in small rodents are of particular interest as they most closely simulate the development and growth of colonic cancer in humans. Micro-computed tomography has been used for detection of polyps in murine models of colon cancer. The study was performed to evaluate whether a novel high-speed continuous-rotation, single-breath-hold scanning protocol in combination with double-contrasting of the colon can be successfully applied for colonoscopy of live mice at acquisition times of 40 s. C57BL/6JApcMin/+ mice were intubated and ventilated. After double-contrasting the colon with barium and air, mice underwent continuous rotation micro-CT (mean resolution 41 × 41 × 53 μm) during a single-breath-hold period of 40 s. Sensitivity to detect colon polyps by four blinded radiologists was analysed. Number and location of polyps were verified in the excised colon. Radiation dose was measured using a thermoluminescence dosimeter placed within the distal colon. In six of seven mice, a total of 12 polyps were detected in the explanted colon (one mouse without polyps). One tumor (8.3%) was located in the proximal third, seven tumors (58.1%) and four tumors (33.2%) were located in the middle and in the distal third of the colon, respectively. Mean tumor volume was 6.5 ± 3.6 mm(3). Sensitivity to detect colon polyps was 0.85 ± 0.1. Mean radiation dose was 0.241 ± 0.002 Gy. Using a high-speed continuous rotation micro-CT protocol, double-contrast single-breath-hold colonoscopy in mice is feasible and yields sufficient contrast to visualize the proximal colonic folds and to detect colonic polyps in vivo.
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Effect of mouth opening on bypass function after combined revascularization for Moyamoya disease.
Acta neurochirurgica. Supplement. 01/2011; 112:35-8.
Moyamoya disease represents a rare steno-occlusive disease of the internal carotid artery (ICA) with a reactive and pathological basal network of collateral vessels. It may lead to ischemic stroke or intracerebral hemorrhage. Treatment options are either direct or indirect revascularization procedur... [more] Moyamoya disease represents a rare steno-occlusive disease of the internal carotid artery (ICA) with a reactive and pathological basal network of collateral vessels. It may lead to ischemic stroke or intracerebral hemorrhage. Treatment options are either direct or indirect revascularization procedures or a combination thereof. Specialized centers report sufficient revascularization in most patients and low complication rates.Between 2005 and 2008, direct extra-intracranial bypass surgery in combination with encephalomyosynangiosis (EMS) was performed in 71 Moyamoya patients at the Mannheim University Medical Center.Following one case of reversible neurological deficits associated with mouth opening, we prospectively evaluated the effect of mouth opening on bypass function in this patient and four further consecutive patients by digital subtraction angiography.Three out of five patients showed alterations in bypass patency upon mouth opening. The obstruction was located at the junction of the bypass and the temporal muscle. Two temporary occlusions and one case of decreased flow were observed. One patient demonstrated reversible hemiparesis and aphasia.
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3.54Impact points
Abciximab does not prevent ischemic lesions related to cerebral angiography: a randomized placebo-controlled trial.
Cerebrovascular diseases (Basel, Switzerland). 01/2011; 31(4):353-7.
To assess the efficiency of IIb/IIIa platelet receptor inhibition by abciximab in the prevention of silent embolism during digital subtraction angiography. In this randomized, double-blind, prospective study, pre- and postangiographic diffusion-weighted magnetic resonance imaging (DWI) of 184 partic... [more] To assess the efficiency of IIb/IIIa platelet receptor inhibition by abciximab in the prevention of silent embolism during digital subtraction angiography. In this randomized, double-blind, prospective study, pre- and postangiographic diffusion-weighted magnetic resonance imaging (DWI) of 184 participants was evaluated for the occurrence of silent embolism. No significant relationship was found between the patients receiving abciximab before digital subtraction angiography (15 of 90; 16.7%) and patients in the placebo group (16 of 94; 17.0%) regarding postangiographic appearance of silent emboli (p = 0.9). IIb/IIIa receptor inhibition by abciximab does not diminish the occurrence of silent embolism during digital subtraction angiography. Our findings indicate that solid blood clots are not the origin of hyperintense lesions observed on DWI and enhance the role of alternative mechanisms.
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4.41Impact points
Expansion of the Multi-Link Frontier™ coronary bifurcation stent: micro-computed tomographic assessment in human autopsy and porcine heart samples.
PloS one. 01/2011; 6(7):e21778.
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 res... [more] 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. The aim of this study was to assess the expansion of the Multi-Link (ML) Frontier™ stent in human and porcine coronary arteries to provide the cardiologist with useful in-vitro information for stent implantation and selection. Nine ML Frontier™ stents were implanted in seven human autopsy heart samples with known coronary artery disease and five ML Frontier™ stents were implanted in five porcine hearts. Proximal, distal and side branch diameters (PD, DD, SBD, respectively), corresponding opening areas (PA, DA, SBA) and the mean stent length (L) were assessed by micro-computed tomography (micro-CT). PD and PA were significantly smaller in human autopsy heart samples than in porcine heart samples (3.54±0.47 mm vs. 4.04±0.22 mm, p = 0.048; 10.00±2.42 mm(2) vs. 12.84±1.38 mm(2), p = 0.034, respectively) and than those given by the manufacturer (3.54±0.47 mm vs. 4.03 mm, p = 0.014). L was smaller in human autopsy heart samples than in porcine heart samples, although data did not reach significance (16.66±1.30 mm vs. 17.30±0.51 mm, p = 0.32), and significantly smaller than that given by the manufacturer (16.66±1.30 mm vs. 18 mm, p = 0.015). Micro-CT is a feasible tool for exact surveying of dedicated stent systems and could make a contribution to the development of these devices. The proximal diameter and proximal area of the stent system were considerably smaller in human autopsy heart samples than in porcine heart samples and than those given by the manufacturer. Special consideration should be given to the stent deployment procedure (and to the follow-up) of dedicated stent systems, considering final intravascular ultrasound or optical coherence tomography to visualize (and if necessary optimize) stent expansion.
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4.41Impact points
Micro-CT based experimental liver imaging using a nanoparticulate contrast agent: a longitudinal study in mice.
PloS one. 01/2011; 6(9):e25692.
Micro-CT imaging of liver disease in mice relies on high soft tissue contrast to detect small lesions like liver metastases. Purpose of this study was to characterize the localization and time course of contrast enhancement of a nanoparticular alkaline earth metal-based contrast agent (VISCOVER ExiT... [more] Micro-CT imaging of liver disease in mice relies on high soft tissue contrast to detect small lesions like liver metastases. Purpose of this study was to characterize the localization and time course of contrast enhancement of a nanoparticular alkaline earth metal-based contrast agent (VISCOVER ExiTron nano) developed for small animal liver CT imaging. ExiTron nano 6000 and ExiTron nano 12000, formulated for liver/spleen imaging and angiography, respectively, were intravenously injected in C57BL/6J-mice. The distribution and time course of contrast enhancement were analysed by repeated micro-CT up to 6 months. Finally, mice developing liver metastases after intrasplenic injection of colon carcinoma cells underwent longitudinal micro-CT imaging after a single injection of ExiTron nano. After a single injection of ExiTron nano the contrast of liver and spleen peaked after 4-8 hours, lasted up to several months and was tolerated well by all mice. In addition, strong contrast enhancement of abdominal and mediastinal lymph nodes and the adrenal glands was observed. Within the first two hours after injection, particularly ExiTron nano 12000 provided pronounced contrast for imaging of vascular structures. ExiTron nano facilitated detection of liver metastases and provided sufficient contrast for longitudinal observation of tumor development over weeks. The nanoparticulate contrast agents ExiTron nano 6000 and 12000 provide strong contrast of the liver, spleen, lymph nodes and adrenal glands up to weeks, hereby allowing longitudinal monitoring of pathological processes of these organs in small animals, with ExiTron nano 12000 being particularly optimized for angiography due to its very high initial vessel contrast.
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0.48Impact points
[A child's birthday with consequences].
Der Radiologe. 12/2010; 50(12):1128-31.
Foreign body ingestion is a common pediatric emergency and if the foreign body cannot be detected radiologically or endoscopically further investigations are required. In this article the case of a radiolucent, ingested foreign body (mini-candleholder of a birthday cake) is presented. The foreign bo... [more] Foreign body ingestion is a common pediatric emergency and if the foreign body cannot be detected radiologically or endoscopically further investigations are required. In this article the case of a radiolucent, ingested foreign body (mini-candleholder of a birthday cake) is presented. The foreign body could not initially be identified via X-ray and endoscopy due to its parapharyngeal localization but was finally visualized by magnetic resonance imaging (MRI) which additionally uncovered the co-existence of acute mediastinal inflammation.
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Dual-energy CT after peri-interventional subarachnoid haemorrhage: a feasibility study.
Clinical neuroradiology. 11/2010; 20(4):231-5.
The aim was to assess the feasibility of dual-energy computed tomography (DE-CT) for detection of peri-interventional re-bleeding in patients with aneurysmal subarachnoid hemorrhage (re-SAH). For in vitro-analyses DE-CT of partially clotted blood intermixed with fresh blood containing contrast agent... [more] The aim was to assess the feasibility of dual-energy computed tomography (DE-CT) for detection of peri-interventional re-bleeding in patients with aneurysmal subarachnoid hemorrhage (re-SAH). For in vitro-analyses DE-CT of partially clotted blood intermixed with fresh blood containing contrast agent was performed. In a clinical setting, 4 patients routinely underwent DE-CT after suspected peri-interventional re-SAH. DE-CT source data images, iodine maps and virtual non-contrast images (VNC) were analyzed and regions-of-interest (ROI) measurements of density values were performed. In vitro experiments demonstrated the feasibility of DE-CT to discriminate between blood with and without contrast agent. In all patients peri-interventional re-SAH was confirmed by detection of extravasated iodine within the subarachnoid spaces in post-interventional DE-CT. Dual-energy CT allowed the discrimination of old blood clots of the initial SAH and blood originating from peri-interventional re-SAH. After subtraction of the iodine-related high density signal, VNC images optimized the estimation of the true amount of subarachnoid blood. Dual-energy CT allows the discrimination and subtraction of blood and iodine mixed within the subarachnoid spaces in patients with peri-interventional re-SAH. It helps to avoid overestimation of SAH after peri-interventional re-bleeding and therefore is a potentially valuable tool in the assessment of peri-interventional re-SAH.
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1.69Impact points
SOM230 (pasireotide) and temozolomide achieve sustained control of tumour progression and ACTH secretion in pituitary carcinoma with widespread metastases.
Experimental and clinical endocrinology & diabetes : official journal, German Society of Endocrinology [and] German Diabetes Association. 05/2010; 118(10):760-3.
Pituitary carcinomas are rare and neurosurgically challenging lesions, as they commonly relapse after surgical removal. Their prognosis is dismal due to their limited response to radiotherapy and chemotherapy. In recent studies, temozolomide was administered in very few patients with partial effects... [more] Pituitary carcinomas are rare and neurosurgically challenging lesions, as they commonly relapse after surgical removal. Their prognosis is dismal due to their limited response to radiotherapy and chemotherapy. In recent studies, temozolomide was administered in very few patients with partial effects. We report a patient with an ACTH-secreting pituitary carcinoma and widespread intracranial, spinal and systemic metastases despite repeated surgical treatment, bilateral adrenalectomy, medical treatment and radiotherapy. Additionally to chemotherapy with temozolomide, the patient received SOM230 as salvage therapy with an improvement of the patient's clinical status, and a reduction of ACTH levels. After 12 months of combination therapy a sustained tumor control was achieved and persisted upon monotherapy with SOM230 for more than 9 months thereafter. Thus, temozolomide in combination with SOM230 seems to be promising in patients with ACTH-secreting metastasized pituitary carcinoma.
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1.30Impact points
TrueFISP imaging of the pineal gland: more cysts and more abnormalities.
Clinical neurology and neurosurgery. 04/2010; 112(3):204-8.
Although pineal cysts are found with a frequency of over one third in autopsy series, prevalences reported in standard magnetic resonance imaging (MRI) studies only range between 0.14% and 4.9%. With the advances in scanner technology and more sensitive high-resolution 3D-sequences, pineal cysts wit... [more] Although pineal cysts are found with a frequency of over one third in autopsy series, prevalences reported in standard magnetic resonance imaging (MRI) studies only range between 0.14% and 4.9%. With the advances in scanner technology and more sensitive high-resolution 3D-sequences, pineal cysts with atypical appearance are more frequently encountered as an incidental finding. In order to help the radiologist and the clinician to correctly interpret these incidental findings and to avoid follow-up MRI or even surgical intervention, we analysed the frequency of typical and atypical pineal cysts using standard MRI-sequences and a high-resolution 3D-trueFISP-sequence (true-Fast-Imaging-with-Steady-State-Precession). In 111 patients undergoing MRI we analysed the prevalence of pineal cysts in relation to gender and age, as well as the frequency of atypical cysts defined by thickened rim, trabeculations, or asymmetric form using three standard MRI-sequences (T1-SE (T1 weighted spin echo), T2-TSE (T2 weighted turbo spin echo), FLAIR (fluid attenuated inversion recovery)) and compared the diagnostic certainty of these standard sequences with the sensitivity of a high-resolution trueFISP MRI sequence. Using trueFISP pineal cysts were detected more frequently than in the standard sequences (35.1% vs. 9.0% (T1-SE), 4.5% (T2-TSE) and 9.0% (FLAIR)). Diagnostic uncertainty was least frequent in trueFISP. In trueFISP, 41.0% of the detected cysts showed one or more features of atypical cysts (standard sequences: 21.4%). Highest prevalence of cysts was detected in the group of 20-30-year-old patients and decreased with increasing age. High-resolution 3D-sequences like trueFISP increase the detection rate of pineal cysts to levels reported in autoptic series while decreasing the diagnostic uncertainty. Atypically configurated pineal cysts are frequently detected as an incidental finding.
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1.43Impact points
First experiences with low-dose anti-angiogenic treatment in gliomatosis cerebri with signs of angiogenic activity.
Anticancer research. 09/2009; 29(8):3261-7.
BACKGROUND: Gliomatosis cerebri is a rare primary cerebral tumour entity characterized by diffuse infiltrative growth patterns representing a WHO grade III malignancy. The prognosis is dismal and therapeutical options are still controversial. In contrast to other high-grade gliomas, angiogenesis is ... [more] BACKGROUND: Gliomatosis cerebri is a rare primary cerebral tumour entity characterized by diffuse infiltrative growth patterns representing a WHO grade III malignancy. The prognosis is dismal and therapeutical options are still controversial. In contrast to other high-grade gliomas, angiogenesis is thought to be absent in gliomatosis cerebri. PATIENTS AND METHODS: Despite this assumption, histopathological analyses of samples of six patients with gliomatosis cerebri were performed and surprisingly there was angiogenic activity with expression of vascular endothelial growth factor and cyclooxygenase 2. It was therefore decided to administer continuous low-dose chemotherapy with temozolomide and celecoxib for antiangiogenic treatment in the four patients that were in good clinical condition following external radiotherapy. RESULTS: In all patients, treatment was well tolerated and MRI follow-up showed no tumour progression for at least six months. One patient died due to pulmonary embolism 9 months after diagnosis; another patient survived 15 months after diagnosis with progressive disease in the last follow-up MRI before death. Two other patients at the present time are still in a stable clinical condition without signs of tumour progression in MRI (12 and 18 months). CONCLUSION: From our initial experience in a small number of patients with gliomatosis cerebri with signs of angiogenic activity, we conclude that low-dose chemotherapy might provide a promising approach for treatment of these patients and that overexpression of angiogenic factors such as VEGF or COX-2 seems to be more frequent than hitherto reported.
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3.76Impact points
Application of Micro-CT in Small Animal Imaging.
Methods (San Diego, Calif.). 09/2009;
Over the past decade, the number of publications using micro-computed tomography (muCT) imaging in preclinical in vivo studies has risen exponentially. Higher spatial and temporal resolution are the key technical advancements that have allowed researchers to capture increasingly detailed anatomical ... [more] Over the past decade, the number of publications using micro-computed tomography (muCT) imaging in preclinical in vivo studies has risen exponentially. Higher spatial and temporal resolution are the key technical advancements that have allowed researchers to capture increasingly detailed anatomical images of small animals, and to monitor the progression of disease in small animal models. The purpose of this review is to present the technical aspects of muCT, as well as, current research applications. Our objectives are threefold: to familiarize the reader with the basics of muCT-techniques; to present the type of experimental designs currently used; and to highlight limitations, future directions, in muCT-scanner research applications, and experimental methods. As a first step we present different muCT setups and components, as well as, image contrast generation principles. We then present experimental approaches in order of the evaluated organ system. Finally, we provide a short summary of some of the technical limitations of muCT imaging, and discuss potential future developments in muCT-scanner techniques and experimental setups.
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3.76Impact points
Vascular Imaging in Small Rodents Using Micro-CT.
Methods (San Diego, Calif.). 09/2009;
In vivo animal models of neoplasm, stroke, subarachnoid haemorrhage, and other diseases involving alterations in vessel anatomy and diameter, require a fast and easy-to-use imaging tool that captures anatomical structure and biologic function data. Micro-computed tomography angiography (muCTA) offer... [more] In vivo animal models of neoplasm, stroke, subarachnoid haemorrhage, and other diseases involving alterations in vessel anatomy and diameter, require a fast and easy-to-use imaging tool that captures anatomical structure and biologic function data. Micro-computed tomography angiography (muCTA) offers high spatial and temporal resolution and is suitable to perform this task. However, conducting muCTA in small rodents, especially in mice, requires a high degree of accuracy and precision. This article describes a setup for in vivo muCTA in mice using both a bolus technique with a conventional contrast agent, as well as, angiography with a blood pool contrast agent. Our setup in mice is at isotropic resolutions up to 16 mum with scanning times less than one minute. The described protocol also addresses some of the technical challenges associated with the imaging of vascular structures in mice models.
Following (4)
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Thomas Henzler
University Medical Center Mannheim, Medical Faculty Mannheim - University of Heidelberg -
Sabine Weckbach
University Hospital Munich- Grosshadern Campus -
Ingo Nölte
Universität Heidelberg -
Soenke Bartling
German Cancer Research Center / UMC Mannheim
