Cervical soft tissue imaging using a mobile CBCT scanner with a flat panel detector in comparison with corresponding CT and MRI data sets.

OBJECTIVE: The aim of this study was to evaluate soft tissue image quality of a mobile cone-beam computed tomography (CBCT) scanner with an integrated flat-panel detector. STUDY DESIGN: Eight fresh human cadavers were used in this study. For evaluation of soft tissue visualization, CBCT data sets and corresponding computed tomography (CT) and magnetic resonance imaging (MRI) data sets were acquired. Evaluation was performed with the help of 10 defined cervical anatomical structures. RESULTS: The statistical analysis of the scoring results of 3 examiners revealed the CBCT images to be of inferior quality regarding the visualization of most of the predefined structures. Visualization without a significant difference was found regarding the demarcation of the vertebral bodies and the pyramidal cartilages, the arteriosclerosis of the carotids (compared with CT), and the laryngeal skeleton (compared with MRI). Regarding arteriosclerosis of the carotids compared with MRI, CBCT proved to be superior. CONCLUSIONS: The integration of a flat-panel detector improves soft tissue visualization using a mobile CBCT scanner.     

Buchbesprechungen

Ohne Zusammenfassung     

Treatment of refractory complex-partial status epilepticus with propofol: case report

PURPOSE: We report a case of a 65-year-old woman who had a subarachnoid and intraventricular hemorrhage secondary to rupture of an anterior communicating artery aneurysm and developed nonconvulsive status epilepticus of the complex-partial type, refractory to phenytoin (PHT), phenobarbital (PB), valproate (VPA), and lorazepam (LZP). METHODS: Three weeks after diagnosis of nonconvulsive status epilepticus, general anesthesia was induced with propofol and titrated to burst suppression on the electroencephalogram (EEG). RESULTS: During propofol infusion, the serum VPA level declined markedly, and despite >3 g daily doses, did not return to the therapeutic range, until several days after propofol was discontinued. Continuous propofol infusion was stopped after 7 days, and the patient recovered consciousness. Despite further complications, she gradually regained normal function and was discharged home 4 months after surgery. CONCLUSIONS: This is the first case of nonconvulsive status epilepticus successfully treated with propofol.     

Efficacy of Anti-inflammatory Agents to Improve Symptoms in Patients With Schizophrenia: An Update

Background: The inflammatory hypothesis of schizophrenia is not new, but recently it has regained interest because more data suggest a role of the immune system in the pathogenesis of schizophrenia. If increased inflammation of the brain contributes to the symptoms of schizophrenia, reduction of the inflammatory status could improve the clinical picture. Lately, several trials have been conducted investigating the potential of anti-inflammatory agents to improve symptoms of schizophrenia. This study provides an update regarding the efficacy of anti-inflammatory agents on schizophrenic symptoms in clinical studies performed so far. Methods: An electronic search was performed using PubMed, Embase, the National Institutes of Health web site http://www.clinicaltrials.gov, Cochrane Schizophrenia Group entries in PsiTri, and the Cochrane Database of Systematic Reviews. Only randomized, double-blind, placebo-controlled studies that investigated clinical outcome were included. Results: Our search yielded 26 double-blind randomized controlled trials that provided information on the efficacy on symptom severity of the following components: aspirin, celecoxib, davunetide, fatty acids such as eicosapentaenoic acids and docosahexaenoic acids, estrogens, minocycline, and N-acetylcysteine (NAC). Of these components, aspirin (mean weighted effect size [ES]: 0.3, n = 270, 95% CI: 0.06–0.537, I² = 0), estrogens (ES: 0.51, n = 262, 95% CI: 0.043–0.972, I² = 69%), and NAC (ES: 0.45, n = 140, 95% CI: 0.112–0.779) showed significant effects. Celecoxib, minocycline, davunetide, and fatty acids showed no significant effect. Conclusion: The results of aspirin addition to antipsychotic treatment seem promising, as does the addition of NAC and estrogens. These 3 agents are all very broadly active substances, and it has to be investigated if the beneficial effects on symptom severity are indeed mediated by their anti-inflammatory aspects.Key words: add-on antipsychotic therapy, aspirin, N-acetylcysteine, estrogens     

Einsatz der molekularen Karyotypisierung in der Pädiatrie

The use of microarray-based high-resolution molecular karyotyping has significantly improved genetic diagnostics in children with congenital disabilities. The high resolution of this technique leads to an increase in the detection rate from 10?% in conventional cytogenetic diagnostics to 20?% for chromosomal imbalances (e.g., deletions) in patients with mental retardation and other abnormalities. The application of molecular karyotyping has changed the diagnostic algorithms in cases of suspicious chromosomal abnormality, in that the new method is increasingly replacing conventional cytogenetics, at least if no known chromosomal syndrome (e.g., Down syndrome or Ullrich–Turner syndrome) is expected. Although array-based molecular karyotyping leads to a higher detection rate of chromosomal imbalances, it is not suitable for the detection of balanced chromosomal rearrangements, pointing towards a potentially transmittable chromosome aberration, e.g., reciprocal translocation or inversion. For this purpose conventional cytogenetic analysis remains the method of choice. It should also be mentioned that the currently available data do not allow prediction of the clinical utility and validity of every detected chromosomal variant. Furthermore, guidelines about how to deal with incidental findings are still not available. Given these challenges in interpretation and mediation of array results, close case-related collaboration of pediatricians and human geneticists is mandatory. This ensures an optimal support – within the frame of the Genetic Diagnosis Act – for the patients and their families.     

Multislice computed tomography-urography: intraindividual comparison of different preparation techniques for optimized depiction of the upper urinary tract in an animal model

OBJECTIVES: We sought to evaluate intraindividually 3 different preparation protocols for achieving improved opacification and anatomic depiction of the upper urinary tract in multisclice computed tomography urography (MSCTU) using a porcine model. MATERIAL AND METHODS: MSCTU was performed in 8 healthy pigs. Each animal underwent 3 MSCT urographies using 3 different preparations before the injection of contrast material: A, intravenous (iv) saline (250 mL); B, iv low-dose furosemide (0.1 mg/kg); and C, iv saline (250 mL) plus iv low-dose furosemide (0.1 mg/kg). Image analysis was performed blinded to the applied protocols and included the evaluation of the opacification and anatomic depiction of the upper urinary tract by means of graded scales. Ureteral distension was determined and density was measured within the collecting system. RESULTS: Furosemide significantly improved both mean opacification scores and mean scores of anatomic depiction compared with the exclusive infusion of saline for MSCTU. There was no significant difference between the application of furosemide and the combination of furosemide plus saline. A significant increase of 25-26% for ureteral distension was found when furosemide was applied. Significant lower mean attenuation values (Hounsfield units) and standard deviation were found within the opacified urine for diuretic-enhanced MSCTU. CONCLUSIONS: Low-dose furosemide injection is superior to saline infusion for achieving optimal enhancement in MSCTU. It is not necessary to combine furosemide and saline infusion. In MSCTU, low-dose furosemide is a simple add-on simplifying image acquisition timing and removing the need for abdominal compression devices.     

Enhancing the response to interferon-alpha.

BACKGROUND: Though initially recognized as antiviral agents, it was soon demonstrated that certain neoplasms were particularly sensitive to interferon-alpha (IFN-alpha). Indeed, the initial success of systemic IFN-alpha treatment in AIDS-associated Kaposi's sarcoma (AIDS-KS) occurred before identification of the human immunodeficiency virus (HIV) and in the absence of any coherent view of KS pathogenesis. With a more comprehensive understanding how KS develops and which circumstances provide an increased virulence of this neoplasm in HIV-infected persons, a more subtle rationale for IFN-alpha treatment arose regarding the disorder of the endogenous IFN-system in HIV-positive individuals. Until recently IFN-alpha was the only therapy available for patients with chronic hepatitis C (CHC). However, no more than 30% of these patients show a sustained virological response. Initial therapy with a combination therapy of IFN-alpha and ribavirin turned out to be more effective than treatment with IFN-alpha alone. To ameliorate response rates in antiviral IFN-therapy a profound understanding of viral dynamics, as well as immunological conditions associated with viral persistence, seems to be essential. Within a conference of the European Society of Clinical Virology (ESCV), which took place in Hamburg from August 30 to September 2, 1998, and was entitled 'Progress in Clinical Virology IV', a satellite symposium was organized to evaluate the clinical results of special antiviral treatment options with IFN-alpha, to analyze treatment failures with this cytokine and to ameliorate future strategies of IFN-alpha therapy. It focussed on HIV-related complications as coinfection with hepatitis C virus (HCV) and AIDS-KS, respectively. METHODS: A kinetic model of HCV infection based on principles established in studying HIV-1 infection was presented which is predictive for the outcome of IFN-alpha treatment. It involves different rates of velocity and compares the rates of acute clearance after different dosages of IFN-alpha application. Using the hypothesis to fit the changes in serum HCV RNA measured in a set of patients, it was found that 5 mIU daily dosing on average blocks 81% of HCV production/release, whereas 10 or 15 mIU blocks about 95% of HCV production/release. RESULTS: Only recently clinical data revealed a greater benefit of combination therapy with IFN-alpha and ribavirin compared to IFN-alpha alone in patients with chronic hepatitis C. In 345 CHC patients relapsing after pretreatment with IFN-alpha monotherapy, sustained response was achieved in a 10-fold higher degree with a combination of IFN and ribavirin compared to patients retreated with IFN alone. In 1775 treatment-naive patients with CHC, response rates to the combination therapy was significantly higher in all patient groups with more than 60% of sustained virological response in patients with genotype 2 and 3, while patients with genotype 1 (poorer prognosis) benefit from extended combination treatment duration from 24 to 48 weeks (17 versus 29% of sustained virological response), respectively. CONCLUSIONS: As viral dynamics on one side and host immune response on the other feature as two landmarks on which the manifestation of viral persistence and chronic viral infections is established, some similarities of HCV and HIV disease are striking. An unusual endogenous IFN-alpha system is associated with both infections and is a negative prognostic factor to response to treatment with IFN-alpha in CHC as well as AIDS-KS. The consequences for treatment options with IFN are a combination with ribavirin in CHC and a graduated systemic treatment schedule in AIDS-KS starting with IFN-treatment in early disease followed by chemotherapy in advanced stages of KS.     

Image registration and analysis for quantitative myocardial perfusion: application to dynamic circular cardiac CT

Large area detector computed tomography systems with fast rotating gantries enable volumetric dynamic cardiac perfusion studies. Prospectively, ECG-triggered acquisitions limit the data acquisition to a predefined cardiac phase and thereby reduce x-ray dose and limit motion artefacts. Even in the case of highly accurate prospective triggering and stable heart rate, spatial misalignment of the cardiac volumes acquired and reconstructed per cardiac cycle may occur due to small motion pattern variations from cycle to cycle. These misalignments reduce the accuracy of the quantitative analysis of myocardial perfusion parameters on a per voxel basis. An image-based solution to this problem is elastic 3D image registration of dynamic volume sequences with variable contrast, as it is introduced in this contribution. After circular cone-beam CT reconstruction of cardiac volumes covering large areas of the myocardial tissue, the complete series is aligned with respect to a chosen reference volume. The results of the registration process and the perfusion analysis with and without registration are evaluated quantitatively in this paper. The spatial alignment leads to improved quantification of myocardial perfusion for three different pig data sets.