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Biomedical subjects

W Heindel

Publications and source records attributed to W Heindel.

At least 37 records · Page 2Linked to original sources
PubMed2003

Inflammatory thromboembolic complication after craniopharyngioma surgery?

Aside from endocrine or visual disturbances an appearance of other complications after craniopharyngioma surgery is rare. We report a case of delayed brain infarction in the postoperative period of craniopharyngioma resection. A 30-year-old man presented with visual impairment and diabetes insipidus. Imaging revealed a partly cystic, partly contrast enhancing intra-/suprasellar mass lesion. The patient underwent craniotomy with resection of the tumour. Histological examination revealed an adamantinomatous craniopharyngioma. Early postoperative an aseptic meningitis, which was diagnosed clinically as well as by laboratory and CSF analysis, resolved spontaneously. One week later a cerebral incident with infarction in the peripheral territory of MCA on the left side occurred. For this unusual event with a review of the literature a thromboembolic origin is suggested on the basis of inflammatory vascular involvement after an attack of aseptic meningitis.

Acute Disease↗
PubMed2003

Plasma cell granuloma involving the brain and the lung.

BACKGROUND: Symptomatic plasma cell granulomas (PCG) of the central nervous system (CNS) are a rare entity, especially in association with an extracranial manifestation. CLINICAL PRESENTATION: A 13 years old boy was operated on for a symptomatic plasma cell granuloma of the lower lobe of the left lung. Four years later, he suffered his first generalized seizure. CT and MRI scans revealed a small hyperdense lesion, which was located in the right frontal lobe, adjacent to the motor strip. Intervention. Stereotactic guided surgery was performed. A plasma cell granuloma was found, which histopathologically resembled the intrapulmonary lesion, which had been removed four years ago. CONCLUSION: Histological findings, differential diagnosis and specific treatment are reviewed and discussed. Patients with PCG should be radiologically staged. Long term prognosis of PCG is good in cases surgically resectable. Nevertheless, patients require lifelong follow up.

Adolescent↗
PubMed2003

Magnetic resonance imaging protocols for examination of the neurocranium at 3 T.

The increasing availability of high-field (3 T) MR scanners requires adapting and optimizing clinical imaging protocols to exploit the theoretically higher signal-to-noise ratio (SNR) of the higher field strength. Our aim was to establish reliable and stable protocols meeting the clinical demands for imaging the neurocranium at 3 T. Two hundred patients with a broad range of indications received an examination of the neurocranium with an appropriate assortment of imaging techniques at 3 T. Several imaging parameters were optimized. Keeping scan times comparable to those at 1.5 T we increased spatial resolution. Contrast-enhanced and non-enhanced T1-weighted imaging was best applying gradient-echo and inversion recovery (rather than spin-echo) techniques, respectively. For fluid-attenuated inversion recovery (FLAIR) imaging a TE of 120 ms yielded optimum contrast-to-noise ratio (CNR). High-resolution isotropic 3D data sets were acquired within reasonable scan times. Some artifacts were pronounced, but generally imaging profited from the higher SNR. We present a set of optimized examination protocols for neuroimaging at 3 T, which proved to be reliable in a clinical routine setting.

Adult↗
PubMed2003

Lung cancer screening with low-dose CT.

Screening for lung cancer is hoped to reduce mortality from this common tumour, which is characterised by a dismal overall survival, relatively well defined risk groups (mainly heavy cigarette smokers and workers exposed to asbestos) and a lack of early symptoms. In the past studies using sputum cytology and chest radiography have failed to demonstrate any reduction in lung cancer mortality through screening. One of the reasons is probably the relatively poor sensitivity of both these tests in early tumours. Low radiation dose computed tomography (CT) has been shown to have a much higher sensitivity for small pulmonary nodules, which are believed to be the most common presentation of early lung cancer. As, however, small pulmonary nodules are common and most are not malignant, non-invasive diagnostic algorithms are required to correctly classify the detected lesions and avoid invasive procedures in benign nodules. Nodule density, size and the demonstration of growth at follow-up have been shown to be useful in this respect and may in the future be supplemented by contrast-enhanced CT and positron emission tomography. Based on these diagnostic algorithms preliminary studies of low-dose CT in heavy smokers have demonstrated a high proportion of asymptomatic, early, resectable cancers with good survival. As, however, several biases could explain these findings in the absence of the ultimate goal of cancer screening, i.e. mortality reduction, most researchers believe that randomised controlled trials including several 10000 subjects are required to demonstrate a possible mortality reduction. Only then general recommendations to screen individuals at risk of lung cancer with low-dose CT should be made. It can be hoped that international cooperation will succeed in providing results as early as possible.

Humans↗
PubMed2003

Metabolic changes within the left dorsolateral prefrontal cortex occurring with electroconvulsive therapy in patients with treatment resistant unipolar depression.

BACKGROUND: The dorsolateral prefrontal cortex (DLPFC) is involved in the pathophysiology of major depression. In particular, metabolic (functional hypometabolism) and structural alterations have been described. In this study metabolic changes within the DLPFC of severely depressed patients before and after electroconvulsive therapy (ECT) were evaluated by proton STEAM spectroscopy (1H-MRS). METHOD: Twelve severely depressed patients with a diagnosis of major depressive episode, unipolar with melancholic features (DSM-IV), were enrolled, and the left dorsolateral prefrontal cortex (DLPFC) was investigated before and after unilateral ECT by 1H-MRS. Three of the four non-responding patients were remeasured a third time after a combined ECT/antidepressant pharmacotherapy. The results were compared with 12 age- and gender-matched controls. RESULTS: In depressed patients reduced glutamate/glutamine (Glx) levels were measured pre-ECT; Glx concentrations correlated negatively with severity of depression. After successful treatment, Glx increased significantly and levels no longer differed from those of age-matched controls. CONCLUSIONS: Our results indicate that major depressive disorder is accompanied by state-dependent metabolic alterations, especially in glutamate/glutamine metabolism, which can be reversed by successful ECT.

Aged↗
PubMed2003

[Dose reduction of radiographs of the pediatric pelvis for diagnosing hip dysplasia using a digital flat-panel detector system].

PURPOSE: To evaluate a possible dose reduction in pediatric pelvic radiographs in congenital hip dysplasia using a digital flat-panel system instead of a phosphor-storage system. MATERIALS AND METHODS: During a six-month period, all pediatric patients referred for pelvic radiography for the evaluation of congenital hip dysplasia were randomly assigned to be examined by either a phosphor-storage system or a digital flat-panel system, whereby the latter system was operated with half the radiation dose. Thirty pairs of radiographs were assessed for the visibility of 16 anatomic details and for 5 orthopedic-radiographic measurements (5-point scale with 1 = excellent; three independent observers). The projection indices of Ball and Kommenda and of Tönnis and Brunken were calculated for all radiographs. The Student's t-test was used to compare the flat-panel and the phosphor-storage radiographs for observers' assessments, patients' age and projection indices. RESULTS: In a total of 7560 observations, the scores for the visibility of anatomic details and orthopedic-radiographic measurements were respectively 2.72 and 2.64 for the flat-panel system and 2.93 and 2.79 for the phosphor-storage system. No significant differences were found between both systems (p > 0.05) and between patient age and projection indices (p > 0.05). CONCLUSION: Pediatric pelvic radiographs can be obtained with a digital flat-panel system using half the radiation dose instead of a phosphor-storage system without sacrificing relevant information in the diagnosis of congenital hip dysplasia.

Age Factors↗
PubMed2003

[Non-occlusive mesenteric ischemia].

The so-called non-occlusive disease (NOD) or non-occlusive mesenteric ischemia (NOMI) is a severe and life-threatening pathology. Even under optimal circumstances and standardised diagnostic and therapeutic procedures maximum survival rates do not exceed 50 %. The NOD is a pathology of the elder patient and its incidence rises with other comorbidities such as reduced cardiac output, diabetes and renal insufficiency. Induction of the disease with a severe vasoconstriction of the splanchnic vessels may be a simple cardiac decompensation, a frequent trigger however is a previous heart surgery with consecutive cardiac shock. Early diagnosis is difficult to conduct because of unspecific symptoms. Beside abdominal pain in awake patients, ileus or subileus is remaining the single acute symptom which could be also a consequence of a postoperative paralysis. Laboratory parameters such as leucocytosis and elevated lactat levels are often positive, but unspecific and the latter may be a delayed sign of progressive disease. The only sufficient method for diagnosis implicating a possible treatment option seems to be an immediate angiographic examination. Because of the disappointing results of a solitary surgical approach transarterial medication via catheter is indicated. Depending of the course of the disease only a combination of local mesenteric infusion of vasodilatory drugs and surgical resection of already necrotic bowel promises a successful therapeutic approach and better survival rates.

Abdominal Pain↗
PubMed2003

[Prospective observation of abdominal ultrasound in radiological emergency services: approaches to cost saving].

PURPOSE: To analyze prospectively abdominal ultrasound in an emergency department (ED) with special emphasis on different routes of obtaining radiology service, reasons for consultation and ordering diagnosis, and to identify strategies for realizing cost savings. MATERIALS AND METHODS: Over a three-month period, the course of events of 295 patients, who entered the ED and underwent on-call sonography, was recorded from the initial presentation to the commencement of treatment, and the results were subsequently evaluated. RESULTS: Of all patients sonographically examined in the ED, 60 % had no prior contact to ambulatory medical services (self-referred, S), 15 % had been sent by a physician (physician-referred, P), and 25 % were inpatients. The most frequent reason for consultation was acute abdominal pain in self-referred patients (70 %) and blunt abdominal trauma in physician-referred patients (70 %). Sonography for acute abdominal pain was considered indicated by the examining radiologist prior to the examination in 90 % (P) and 70 % (S). Sonography contributed to the diagnosis in 44 % (P) and 22 % (S). Patients had to be hospitalized in 80 % (P) and 40 % (S), and needed immediate treatment in 78 % (P) and 43 % (S). Sonography after blunt abdominal trauma was considered appropriate in 90 % (P) and 65 % (S). Diagnostic information was obtained in 90 % (P) and 88 % (S), and therapeutic interventions were required in 10 % (P) and 0 % (S). The admission rate was 97 % (P) and 29 % (S), respectively. CONCLUSIONS: In the ED, sonography was performed with significantly lower clinical effectiveness on self-referred than on physician-referred patients. Substantial cost-savings could be achieved by more selective use of abdominal sonography for self-referred patients.

Abdomen↗
PubMed2003

Assessment of coronary arterial stents by multislice-CT angiography.

PURPOSE: To assess patency and lumen visibility of coronary artery stents by multislice-CT angiography (MSCTA) in comparison with conventional coronary angiography as the standard of reference. MATERIAL AND METHODS: 47 stents of 13 different types were evaluated in 29 patients. MSCTA was performed on a 4-slice scanner with a standard coronary protocol (detector collimation 4 x 1 mm; table feed 1.5 mm/rotation, 400 mAs, 120 kV). Image evaluation was performed by two readers who were blinded to the reports from the catheter angiography. MIP reconstructions were evaluated for image quality on a 4-point scale (1 = poor, 4 = excellent) and stent patency (contrast distal to the stent as an indirect patency sign). Axial images and multiplanar reformations through the stents were used for assessment of stent lumen visibility (measurement of the visible stent lumen diameter) and detection of relevant in-stent stenosis (> or =50%). RESULTS: Image quality was fair to good on average (score 2.64 +/- 1.0) and depended on the heart rate (heart rate 45-60: average score 3.2, heart rate 61-70: average score 2.8, heart rate >71: average score 1.4). Thirty-seven stents were correctly classified as patent, 1 was correctly classified as occluded and 9 stents were not assessible due to insufficient image quality because of triggering artifacts. Parts of the stent lumen could be visualized in 30 cases. On average, 20-40% of the stent lumen diameter was visible. Twenty-five stents were correctly classified as having no stenosis, 1 was falsely classified as stenosed, 1 was correctly classified as occluded. In 20 stents lumen visibility was not sufficient for stenosis evaluation. CONCLUSION: Although the stent lumen may be partly visualized in most stents, a reliable evaluation of in-stent stenoses does not seem practical by 4-slice MSCT. Nevertheless, for stent patency evaluation, MS-CTA might provide valuable clinical information. With submillimeter MSCT (e.g., 16-slice scanners) and more sophisticated reconstruction algorithms, further improvements may be expected.

Aged↗
PubMed2002

Pharmacokinetics of intra-arterial mitomycin C in the chemoembolization treatment of liver metastases with polyvinylalcohol or degradable starch microspheres.

OBJECTIVES: In cancer treatment, arterial blood flow reduction by embolization combined with intra-arterial chemotherapy may be advantageous by achieving high and prolonged drug concentrations in the tumor, and lower systemic drug exposure. The pharmacokinetics of intra-arterial mitomycin C (MMC) was investigated in patients with liver metastases undergoing chemoembolization treatment. METHODS: The chemoembolization treatment consisted of the use of polyvinylalcohol microspheres (ITC-Contour, diameter 150-250 micro m, irreversible vessel occlusion, 20 mg MMC, 15 patients) followed by sealing of the supplying artery with Ethibloc. Alternatively, starch microspheres (Spherex, diameter 45 micro m, biologically degradable, 10 ml of suspension containing 60 mg starch/ml, 20 mg MMC in 7 patients, 15 mg/m2 body surface in 3 patients) were used. MMC was infused over 6 min into the artery supplying the tumor. Serum MMC concentrations were determined from peripheral venous blood samples [protein precipitation with acetonitrile, reverse-phase HPLC with ultraviolet detection (C18 column, elution with 0.01 M, pH 6.5 phosphate buffer/methanol, v/v 70:30, 365 nm)]. The pharmacokinetic parameters were computed assuming an open two-compartment model and linear kinetics. RESULTS: The disposition parameters for MMC in patients treated with polyvinylalcohol microspheres were comparable to data from the literature (C(max)=913+/-98 ng/ml, T(max)=7.7+/-0.3 min, V(c)=0.27+/-0.03 l/kg, V(ss)=0.59+/-0.07 l/kg, Cl=757+/-67 ml/min, T(1/2 alpha)=5.8+/-0.8 min, T(1/2 beta)=50.4+/-4.1 min). There was no significant difference in the disposition parameters for MMC between patients treated with polyvinylalcohol microspheres and those treated with starch microspheres ( P>0.05). In particular, there was no significant difference in the standardized AUC between the groups; this implies that the systemic toxicity of MMC is comparable when polyvinylalcohol microspheres and ethibloc (AUC 1472+/-123 microg min/l per 1 mg MMC) or starch microspheres (AUC: 1448+/-172 microg min/l per 1 mg MMC) are used. CONCLUSION: The AUC values found in this study do not indicate a reduction in the systemic toxicity of MMC if applied intra-arterially in combination with embolizing microspheres, when compared to the AUC values in the literature for intra-arterial application without embolization, or intravenous MMC application. The amount of starch microspheres may have been too small to cause marked effects. On the other hand, there is a very wide range of AUC values reported in the literature for different application modes, and the use of such historical controls is not adequate for detecting more subtle advantages of the chemoembolization procedure, which may, however, exist.

Aged↗
PubMed2002

Visualization of auditory habituation by fMRI.

The aim of this study was to measure and quantify habituation phenomena within the auditory cortex of 18 healthy subjects by means of fMRI. Auditory stimulation was done by digitally generated pulsed (nu = 5 Hz) 800-Hz sine tones with three alternating ON (duration 2 min) and OFF (1 min) periods. Binaural stimulation resulted in symmetrical bihemispheric activation of the auditory cortex. Our data revealed a characteristic signal decay to repeated acoustic stimulation: the response to the second was even more pronounced, and the third stimulation block significantly lower compared to the first. Thus, our data clearly demonstrate habituation phenomena, probably due to reduced neuronal activity with increased duration and/or frequency of stimuli.

Acoustic Stimulation↗
PubMed2002

[Early lung cancer detection with low-dose CT: an update].

Lung cancer is the leading cause of death from malignancy. Due to a lack of early symptoms patients usually undergo therapy at advanced tumor stages when prognosis is poor. Feasibility studies of low-dose spiral CT screening of heavy smokers have shown that many small, resectable lung cancers can be diagnosed at early stages using simple diagnostic algorithms based on size and attenuation of detected pulmonary nodules with a small proportion of invasive procedures for benign lesions. Preliminary results of repeat screening confirms small size and favourable stage distribution of detected cancers, using even simpler diagnostic algorithms: additional diagnostic procedures are only required in new or growing nodules whereas follow-up with low-dose CT is sufficient in nodules that appear unchanged to exclude slow growth. However, mortality reduction by lung cancer screening with low-dose CT has yet to be demonstrated. Several randomised controlled trials are under way to assess possible mortality reduction by comparison of mortalities in a screening group and a control group. It is hoped that through international cooperation data from these trials can be pooled to allow for statistically significant conclusions as early as possible.

Aged↗
PubMed2002

[Pulmonary aspergillosis as initial manifestation of septic granulomatosis (chronic granulomatous disease, CGD) in a premature monozygotic female twin and FDG-PET diagnosis of spread of the disease].

PURPOSE: To present the unusual case of chronic granulomatous disease (CGD) manifestating as pulmonal aspergillosis in female enzygotic twins during the neonatal period. To demonstrate and to discuss the complex diagnosis and the diagnostic value of FDG-PET in monitoring the spread and activity of the disease. PATIENTS: Plain chest x-ray and CT of the lung showed multiple, mostly round lesions in one of the former preterm twins at the age of 8 weeks. The girl with known ASD II was then suffering from dyspnoea and recurrent pulmonary infections. Because of the imaging findings invasive pulmonary aspergillosis due to an underlying immunodeficiency was suspected. RESULTS: Aspergillosis was confirmed histologically and microbiologically by specimens taken from an open lung biopsy. Because of coexisting granulocytic dysfunction the diagnosis of CGD was made. This diagnosis was equally confirmed by noninvasive methods in the asymptomatic sister. FDG-PET did not show any evidence of extra-pulmonary spread of disease. CONCLUSION: CGD can present as isolated pulmonal aspergillosis even in the neonatal period when an immunodeficiency is discussed. In enzygotic twins screening of the asymptomatic twin is mandatory. FDG-PET is a useful tool in screening for spread of the disease and in evaluating disease activity.

Age Factors↗