Three sites of high-flow CSF leakage in spontaneous intracranial hypotension.
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Adult↗
Biomedical subjects
R Brüning
Publications and source records attributed to R Brüning.
[Gadolinium enhancement of the cauda equina following ischemia of the lumbar cord].
Enhancement of the cauda equina is a well-recognized finding, in particular in patients with inflammatory diseases of the peripheral nervous system. However, we report an unusual case of a woman with an ischemic lesion in the lumbar intumescence who developed enhancement of the cauda equina 18 days after disease onset. Seventy-six days after the onset of illness, contrast uptake was no longer detectable. Severe injury to the motor neurons in the lumbar intumescence was evident clinically and electromyographically. We propose that the enhancement of the cauda equina was due to blood-nerve barrier disruption during Wallerian degeneration following ischemic injury to the motor neurons of the lumbar cord.
Adult↗
[The so-called spontaneous low CSF pressure pressure syndrome. Case results indicating a disturbance in CSF/blood volume regulation].
The new IHS classification describes under the paragraph 7.2.3 the headache attributed to spontaneous low CSF pressure. We report on four patients with such a headache and discuss the probable pathophysiology, including results published in the literature. It seems that not the low CSF pressure itself is the cause for the headache but the unphysiological, increased vasodilatation of intracranial and epidural veins. This dilatation of veins also shows up in the typical radiological findings with meningeal contrast enhancement and enlarged epidural veins. A trial with caffeine, theophylline, or indomethacin is recommended; otherwise, the most effective treatment option is an epidural blood patch, which is effective also in the absence of a documented CSF leak.
Adult↗
[Diagnostic evaluation of carotid artery stenoses with multislice CT angiography. Review of the literature and results of a pilot study].
BACKGROUND: The accurate evaluation of carotid artery stenoses is important for therapeutic decision making. Catheter digital subtraction angiography (DSA) still represents the gold standard, while the advent of multislice CT (MSCT) has led to improved temporal and spatial resolutions of CTA. MATERIAL AND METHODS: In a pilot study, we investigated 14 diseased vessels in 9 symptomatic patients (7m, 2f; mean age 60.7+/-10,9 years) comparing biplanar DSA with standardized 16-slice MS-CTA. The degree of stenosis was evaluated in a consensus reading following modified NASCET criteria. RESULTS: DSA demonstrated 4 occlusions, 5 high-grade stenoses (>70%) and 5 lower-grade stenoses (<70%). One dissecting, infrapetrous stenosis was not adequately quantified by CTA due to a close topographic relation to the skull base. In the carotid bifurcation (n=13), an excellent correlation was demonstrated between DSA and CTA with a correlation coefficient of 0.99. CONCLUSION: MS-CTA has a good diagnostic potential in the evaluation of carotid artery stenoses. Larger studies will need to demonstrate the relative diagnostic value for different subtypes of stenosis and for different reader experience levels.
Aged↗
[Value of electron beam tomography (EBT)].
Electron beam tomography (EBT) has been scientifically evaluated to a much lesser degree for non-cardiac indications than for cardiac purposes. Therefore, four groups of investigators in Berlin (2), Mannheim and Munchen, which were supported by the Deutsche Forschungsgemeinschaft (DFG), included applications outside the heart in their evaluation of EBT technology. EBT has proven useful to look for pulmonary embolism and to assess other vessels (aorta, aortic branches, and intracranial arteries). Imaging of the lung parenchyma benefits from its intrinsic high contrast and from the fast data acquisition of EBT. Limited photon efficiency, higher radiation exposure, increased noise levels and other artifacts, however, markedly reduce the value of EBT for imaging of low contrast objects compared to conventional spiral CT and multislice CT (MSCT), compromising, in particular, the morphologic depiction of parenchymal abdominal organs and the brain. Consequently, scientific studies to further evaluate EBT for scanning of the brain and parenchymal abdominal organs were not pursued. Radiation exposure for non-cardiac EBT studies is up to three times higher than that for respective spiral CT studies, and in children EBT can only be advocated in select cases. Radiation exposure for the various prospectively triggered cardiac examination protocols of EBT is lower than that for conventional coronary angiography. Radiation exposure in cardiac multislice CT exceeds severalfold that of EBT, but the dose efficiency of EBT and MSCT are similar due to higher spatial resolution and less image noise of MSCT. In addition, modifications of MSCT (ECG pulsing) can further reduce radiation exposure to the level of EBT. Technical improvements of the EBT successor scanner "e-Speed" enable faster data acquisition at higher spatial resolution. Within comparative studies, the "e-Speed" will have to prove its value and competitiveness, particularly in comparison with multislice CT. After profound scientific assessment in a multicenter evaluation supported by the Deutsche Forschungsgemeinschaft (DFG) and regardless of the specific suitability of electron beam tomography for various cardiac and some non-cardiac indications, the investigators unanimously find the electron beam tomograph Evolution C150 XP not suitable as a whole body CT scanner.
Age Factors↗
[University clinics as centers of radiologic performance alliances in the ambulatory and inpatient sector].
PROBLEM: Health care delivery in Germany has to face severe challenges that will lead to a closer integration of services for in- and out-patients. University hospitals play an important role due to their activities in research, education and health care delivery. They are requested to promote and evaluate new means and ways for health care delivery. METHODS: The Institute of Clinical Radiology at the University Hospital of the Ludwig-Maximilians-University started teleradiological services for hospitals and general practices in January 1999 in the framework of the "Imaging services--teleradiological center of excellence". Legal, technical and organizational prerequisites were analyzed. RESULTS: Networks between university hospitals and general practices are not likely to solve all future problems. They will, however, increase the availability of the knowledge of experts even in rural areas and contribute to a quality ensured health care at the patients home. Future developments may lead to international co-operations and such services may be available to patients abroad. CONCLUSION: Legal, technical and organizational obstacles have to be overcome to create a framework for high quality telemedical applications. University hospitals will play an important role in promoting and evaluating teleradiological services.
Delivery of Health Care↗
[Diagnostic evaluation of the craniocervical vascular system with a 16-slice multi-detector row spiral CT. Protocols and first experiences].
PURPOSE: The newly developed 16-slice multi detector row computed tomography (MDCT) allows for isotropic imaging at rotation times under 500 ms. We aim to describe our first experiences with this novel technology in the diagnostic imaging of the craniocervical vascular system. METHODS: The craniocervical vascular system of 8 consecutive patients was examined with a standardized protocol with the new 16-slice MDCT. The volume covered included the carotid arteries from their origin at the aortic arch and the intracranial arterial and venous vessels in their entirety. Homogeneity of contrast, contrast-to-parenchyma ratios, image quality and radiation doses were assessed. RESULTS: A homogeneous vessel-to-parenchyma ratio was reached in the carotids as well as in the intracranial arterial and venous vessels. Image quality was rated as excellent in all patients. The estimated mean effective radiation dose amounted to 2.31 mSv +/-0.57, the mean dose length product to 608 mGy*cm +/-151. CONCLUSION: The newly developed 16-slice MDCT technology appears to be a promising tool in the diagnostic assessment of the cervicocranial vessels.
Aged↗
[CT-angiographic evaluation of intracranial aneurysms - a review of the literature and first experiences with 4- and 16-slice multi detector CT scanners].
Intracranial aneurysms are a common pathology faced by the diagnostic radiologist in daily practice. They can present as symptomatic aneurysms with a subarachnoid hemorrhage or as an incidental finding in another radiological study. Moreover, clipped or coiled aneurysms sometimes require a postinterventional work-up to exclude residual perfusion. Previous studies assessing the value of CT angiography in the diagnosis of intracranial aneurysms have been conducted using single slice spiral CT-scanners. They have shown a limited sensitivity in the diagnosis of small aneuryms with a diameter of equal to or smaller than 3 mm.Presently, there is only limited experience regarding the use of multi-detector row CT (MDCT) in the diagnosis of intracranial aneurysms. We have examined eight patients with a total of eleven aneurysms with MDCT technology, five patients with a 4-slice MDCT and three with a 16-slice MDCT. Of these, five were untreated aneurysms and six posttherapeutic with a status post surgical clipping. The mean diameter of the aneurysms was 5 mm (range 2 to 13 mm, median 3 mm). Of the treated aneuryms, two showed residual perfusion of the aneurysmal neck with a diameter of 2 and 6 mm respectively. In all cases, MDCT-angiography was in full agreement with the DSA diagnosis. Studies on larger patient populations will need to demonstrate the value of CTA in the diagnosis of intracranial aneurysms compared to the reference standard DSA.
Adult↗
Dynamic susceptibility contrast-enhanced echo-planar imaging of cerebral gliomas. Effect of contrast medium extravasation.
PURPOSE: To assess the influence of the degree of contrast medium extravasation on different DSC EPI MR sequences for perfusion MR imaging. MATERIAL AND METHODS: 60 patients with cerebral gliomas were examined by either an FID EPI or an SE EPI DSC MR sequence. The acquired images were evaluated on a qualitative and quantitative basis. For qualitative assessment, the homogeneity of the signal time curve, image artifacts, the degree of signal drop and the degree of enhancement were evaluated. The quantitative assessment included the percentage of signal drop and the contrast-to-noise ratio of the different EPI sequences was analyzed. RESULTS: FID EPI presented a more homogeneous signal time curve and a more pronounced susceptibility effect than the SE EPI sequence. Due to the lesser susceptibility effect, the SE EPI sequence was not as sensitive to contrast media extravasation. The signal returned to baseline in all patients. In patients with strongly enhancing lesions, the FID EPI sequence suffered from considerable T1 effects, causing problems in the quantification of perfusion data. CONCLUSION: FID EPI sequences were preferred for perfusion MR imaging in patients without strong enhancing lesions, e.g. in ischemia or tumors with intact blood-brain barrier. In patients with suspected strong enhancing lesions, an SE EPI sequence should be used.
Brain Neoplasms↗
Case-oriented computer-based-training in radiology: concept, implementation and evaluation.
BACKGROUND: Providing high-quality clinical cases is important for teaching radiology. We developed, implemented and evaluated a program for a university hospital to support this task. METHODS: The system was built with Intranet technology and connected to the Picture Archiving and Communications System (PACS). It contains cases for every user group from students to attendants and is structured according to the ACR-code (American College of Radiology) 2. Each department member was given an individual account, could gather his teaching cases and put the completed cases into the common database. RESULTS: During 18 months 583 cases containing 4136 images involving all radiological techniques were compiled and 350 cases put into the common case repository. Workflow integration as well as individual interest influenced the personal efforts to participate but an increasing number of cases and minor modifications of the program improved user acceptance continuously. 101 students went through an evaluation which showed a high level of acceptance and a special interest in elaborate documentation. CONCLUSION: Electronic access to reference cases for all department members anytime anywhere is feasible. Critical success factors are workflow integration, reliability, efficient retrieval strategies and incentives for case authoring.
Computer Communication Networks↗
Intercalation of a pendant-arm tetraazamacrocycle into molybdenum disulfide.
A novel macrocycle-MoS2 nanocomposite has been synthesized and characterized using the exfoliation/restacking properties of LiMoS2, providing the first of a new family of intercalation compounds.
Journal Article↗
[Exclusion of coronary calcium with electron beam tomography: an effective filter before invasive diagnosis in symptomatic patients?].
Electron beam computed tomography (EBCT) is the most sensitive and accurate method of measuring coronary calcium which indicates coronary atherosclerosis. We performed a prospective study in 1764 symptomatic patients who were referred to our hospital for coronary angiography because of suspected coronary artery disease. In all of these patients cardiac catheterization and coronary calcium scanning was performed within 3.2 +/- 4 days. 454/1225 men (37.0%) and 165/539 women (30.6%) had significant coronary stenoses > or = 75%. Only two men (0.4%) and no single woman (0.0%) with stenoses > or = 75% and only 3/323 patients (0.9%) with moderate stenoses (50-75%) did not exhibit coronary calcium. Coronary angiography excluded stenoses in 822 patients. Of these patients 261 (29.4%) did not reveal coronary calcium. In younger patients (< 60 years) without stenosis exclusion of coronary calcium was a frequent finding: 31% of men and 55.8% of women were free of coronary calcium. Thus, exclusion of coronary calcium with electron beam tomography defines a substantial subgroup of patients who have an extremely low risk of significant coronary stenosis despite suspected coronary artery disease in history and non-invasive testing. Determination of coronary calcium might, therefore, be an effective filter before invasive angiography in selected groups of symptomatic patients.
Adult↗
Correlation of coronary calcification and angiographically documented stenoses in patients with suspected coronary artery disease: results of 1,764 patients.
OBJECTIVES: This study correlated the electron beam computed tomographic (EBCT) calcium scores with the results of coronary angiography in symptomatic patients in order to assess its value to predict or exclude significant coronary artery disease (CAD). BACKGROUND: Electron beam computed tomography is a sensitive method to detect coronary calcium. However, it is unclear whether it may play a role as a filter before invasive procedures in symptomatic patients. METHODS: A total of 1,764 patients (1,225 men and 539 women) with suspected CAD from a single center were included in our study. All patients underwent calcium screening with EBCT (C150XP Imatron) and conventional coronary angiography. RESULTS: Fifty-six percent of men and 47% of women revealed significant coronary stenoses (> or =50%). Total exclusion of coronary calcium (14% of the study group) was associated with an extremely low probability of stenosis (<1%). With calcium scores > or =20th, > or =100th or > or =75th percentile of age groups, the sensitivity to detect stenoses decreased to 97%, 93% and 81%, respectively, in men and to 98%, 82% and 76%, respectively, in women. At the same time, the specificity increased up to 77% in men and women. There was a significant difference in coronary calcium between men and women in all age groups; however, receiver-operating characteristic curves indicated that the test can be performed with equal accuracy in all of these subgroups. CONCLUSIONS: Calcium screening with EBCT is a highly sensitive and moderately specific test to predict stenotic disease. Exclusion of coronary calcium defines a substantial subgroup of patients, albeit symptomatic, with a very low probability of significant stenoses.
Adult↗
[Value of multiplanar reformations (MPR)in multi-slice spiral CT of the lung].
PURPOSE: To evaluate the quality of multiplanar reformations (MPR) of multidetector spiral-CT (MD-CT) data sets of the chest based on anatomic criteria. METHODS: 90 patients with suspected or known diseases of the lung parenchyma underwent thoracic MD-CT with 1-mm collimation. Axial scans were reconstructed with 1-mm slice width and 0.6-mm reconstruction increment. Coronal and sagittal MPRs were reconstructed with 3, 5 and 8 mm thickness from the axial scans. Three blinded readers rated image quality based on several anatomic criteria and the presence of different artifacts using a 5-point scale. The scores for MPRs were compared with those of 5-mm thick axial scans. RESULTS: All anatomical structure were equally well depicted on MPRs as on axial scans with very good interobserver correlation (kappa 0.69-0.76). Only the lung parenchyma directly adjacent to the heart and the great vessels were visualized with limited quality due to cardiac pulsation artifacts. Advantages of sagittal MPRs include the sharper delineation of interlobar fissures and thus improved anatomic localization of a lesion. Coronal reformations also offer improved anatomic orientation in comparison with 5-mm axial scans. A slice thickness of 5 mm for MPRs yielded best results. CONCLUSIONS: MPRs allow an unrestricted assessment of the lung. Sagittal and coronal reformations improve the topographical visualization of chest anatomy.
Adult↗
[Diagnostic value of different rectal contrast media in the detection of colorectal diseases by multi-slice CT].
PURPOSE: Assessment of 3 different rectal contrast agents (water, methylcellulose, ultrasound gel) for their suitability for colorectal imaging in multislice CT (MS-CT). METHODS: 115 patients with colorectal diseases underwent MS-CT with varying, rectal contrast agents in a prospective study. Images were assessed by 2 independent CT-experienced radiologists. 6 criterias were evaluated, using a 5-point scale. RESULTS: Methylcellulose (MC) proved to be significantly superior to ultrasound gel (US). Especially, differentiation of healthy and diseased bowel and bowel wall and lumen were aided, which was proven by quantitative analysis of attenuation values. Rectal distension is greater using MC or US than for water. More proximal parts of the colon could be better distended with water. The interobserver correlation was good (kappa 0.76). CONCLUSIONS: Rectal filling with MC significantly improves diagnostic confidence in colorectal examinations. Ease of administration and lack of problems suggest its use as a clinical routine tool.
Adult↗
ECG-gated reconstructed multi-detector row CT coronary angiography: effect of varying trigger delay on image quality.
PURPOSE: To evaluate the effectiveness of electrocardiographically (ECG)-gated retrospective image reconstruction for multi-detector row computed tomographic (CT) coronary angiography in reducing cardiac motion artifacts and to evaluate the influence of heart rate on cardiac image quality. MATERIALS AND METHODS: Sixty-five patients with different heart rates underwent coronary CT angiography. Raw helical CT data and ECG tracings were combined to retrospectively reconstruct at the defined consecutive z position with a temporal resolution of 250 msec per section. The starting points of the reconstruction were chosen between 30% and 80% of the R-R intervals. The relationships between heart rate, trigger delay, and image quality were analyzed. RESULTS: Optimal image quality was achieved with a 50% trigger delay for the right coronary artery and 60% for the left circumflex coronary artery. Optimal image quality for the left anterior descending coronary artery was equally obtained at 50% and 60% triggering. A significant negative correlation was observed between heart rate and image quality (P <.05). The best image quality was achieved when the heart rate was less than 74.5 beats per minute. CONCLUSION: To achieve high image quality, the heart rate should be sufficiently slow. Selection of appropriate trigger delays and a decreasing heart rate are effective to reduce cardiac motion artifacts.
Adult↗
Correlations between clinical findings and magnetization transfer imaging metrics of tissue damage in individuals with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.
BACKGROUND AND PURPOSE: We obtained magnetization transfer imaging (MTI) scans from individuals with cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) (1) to investigate the presence, extent, and nature of pathology in white and gray matter outside proton density (PD)-visible lesions; (2) to quantify the degree of tissue damage occurring in lesions seen on PD-weighted scans; and (3) to correlate MTI-derived measures of disease burden with age, physical disability, and cognitive performance. METHODS: Dual-echo, T1-weighted, and MTI scans of the brain were obtained from 33 individuals with CADASIL and 12 control subjects. Magnetization transfer ratio (MTR) values from PD-visible lesions, normal-appearing white matter (NAWM), and normal-appearing gray matter (NAGM) were measured. Histograms of MTR from the whole brain and normal-appearing brain tissue were also produced. RESULTS: All MTR values from NAWM and NAGM regions studied were significantly lower for individuals with CADASIL than for control subjects, with the exception of those obtained from the NAWM of the infratentorial structures and the NAGM of the occipital cortex. The average MTR from PD lesions in individuals with CADASIL was significantly lower than that from all the NAWM regions. Average MTR and peak location from whole-brain and normal-appearing brain tissue histograms were significantly lower for individuals with CADASIL than for control subjects. MTR values from NAWM were strongly correlated with the extent of macroscopic lesions and their average MTR. Apart from NAGM, average MTR from all other tissues studied significantly decreased with increasing age, physical disability, and cognitive impairment. CONCLUSIONS: PD lesions of individuals with CADASIL have variable degrees of tissue damage. Brain tissue outside PD abnormalities is also damaged. This study suggests that the extent and the severity of the brain tissue damage are critical factors in determining clinical status in CADASIL.
Age Factors↗
[Seeding metastasis caused by fine needle biopsy?].
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Biopsy, Needle↗