Preliminary testing for normality: some statistical aspects of a common concept.

BACKGROUND: Statistical methodology has become an increasingly important topic in dermatological research. Adequacy of the statistical procedure depends among others on distributional assumptions. In dermatological articles, the choice between parametric and nonparametric methods is often based on preliminary goodness-of-fit tests. AIM: For the special case of the assumption of normally distributed data, the Kolmogorov-Smirnov test is the most popular choice. We investigated the performance of this test on four types of non-normal data, representing the majority of real data in dermatological research. METHODS: Simulations were run to assess the performance of the Kolmogorov-Smirnov test, depending on sample size and severity of violations of normality. RESULTS: The Kolmogorov-Smirnov test performs badly on data with single outliers, 10% outliers and skewed data at sample sizes < 100, whereas normality is rejected to an acceptable degree for Likert-type data. CONCLUSION: Preliminary testing for normality is not recommended for small-to-moderate sample sizes.

Eruption times of permanent teeth in teenage boys and girls in Izmir (Turkey).

In a study in the Aegean city of Izmir, Turkey, during the summer of 2002, 2101 patients (1046 boys and 1055 girls) were examined. The examination occurred within the framework of a dental check-up performed at two schools and one pre-school unit. The age span ranged from 3.98 to 24.91 years. Sex, age and present permanent teeth were recorded. Wisdom teeth were excluded. The sequence of tooth eruptions differs significantly in the lower and upper jaw, whereas no significant differences existed when comparing the sides of each jaw. The times of tooth eruption is earlier in females than in males. The entire tooth eruption process of the second dentition occurs in females earlier than in males. The tooth eruption in the lower and upper jaw of male and female probands is symmetrical. In comparing the upper and the lower jaw of both genders, it becomes evident that there is a tendency for earlier tooth eruptions in the lower jaw. In respect to the tooth eruption sequence, a change was noted in the upper jaw. Contrary to the reports of other authors, the second premolar has changed places with the canine and erupts prior to this tooth. Otherwise no major differences concerning the sequence of tooth eruptions, when compared to the results gained from other populations, were observed. Concerning the entire dentition, no acceleration of the tooth eruption could be noted. The computed differences of teeth eruption as a mean value calculated over all teeth, was +/- 1 year at maximum, compared to studies from different continents. Oral examination of teeth is a simple tool to calculate tooth eruption intervals. This first investigation on a population of Izmir revealed a change in the eruption sequence of permanent teeth. These findings are relevant for dental treatment planning and forensic odontology and should be reconfirmed at certain intervals.

[Image quality of thin- and thick-slice MSCT reconstructions in low-contrast objects (liver lesions) with equal doses]. / Dünn- und dickschichtige MSCT-Untersuchungen bei Niedrigkontrastobjekten (Leberläsionen): Vergleich der Bildqualität bei gleicher Dosis.

PURPOSE: To evaluate the image quality of thin-section MSCT examinations of low-contrast objects such as liver lesions, and to find out whether a thin slice technique requires an increase in radiation dose. MATERIALS AND METHODS: MSCT examinations of the liver were performed in the portal venous phase on a Volume Zoom Scanner (Siemens, Erlangen) with a collimation of 4 x 2.5 mm, 120 kV, 125 mAs and table speed of 12.5 mm. Forty small hypodense liver lesions with a mean size of 3 mm (1 to 8 mm) were reconstructed using a slice thickness of 3, 5, 7, and 10 mm. All lesions were evaluated for each slice thickness by 3 independent radiologists using a 5-point scale (excellent to poor) for the following 7 criteria: contrast, demarcation and contour of the lesion, image noise and quality, demarcation of liver veins and liver contour. The mean values of the reviewers' scores were calculated. The correlation of the three observers in the evaluation of the criteria was determined using the Kendall's Tau coefficient. RESULTS: The 3-mm thin sections were excellent in the evaluation of lesion detection, lesion contrast and lesion contour with a mean score of 1.4 compared to 4.1 for 10-mm sections. Concerning the criteria image quality and liver contour, thin sections achieved the best results in our series. Image noise was pronounced in thin sections but did not affect negatively the image analysis. Interrater agreement was 0.53 for the criterium image noise. CONCLUSION: Thin sections in MSCT examinations of low contrast objects such as liver lesions do not require an increase in radiation dose because the increase in image noise is compensated by improved lesion contrast.

Functional imaging of parotid glands: diffusion-weighted echo-planar MRI before and after stimulation.

PURPOSE: To investigate the feasibility of diffusion-weighted (DW) echo-planar imaging (EPI) for measuring different functional conditions of the parotid gland and to compare different measurement approaches. MATERIALS AND METHODS: Parotid glands of 27 healthy volunteers were examined with a DW EPI sequence (TR 1,500 msec, TE 77 msec, field-of-view 250 x 250 mm, pixel size 2.10 x 1.95 mm, section thickness 5 mm) before and after oral stimulation with commercially available lemon juice. The b factors used were 0, 500, and 1,000 sec/mm (2). Apparent diffusion coefficient (ADC) maps were digitally transferred to MRIcro (Chris Rorden, University of Nottingham, Great Britain) and evaluated with a manually placed circular region of interest (ROI) containing 100 - 200 pixel. Additional ROIs including the entire parotid gland were placed on either side. The results of both measurements were compared, using the Student's t test based on the median ADC values for each person. A two-tailed p-value of less than.05 was determined to indicate statistical significance. To compare both measurement approaches, the Pearson's correlation coefficient (r) was calculated. RESULTS: Diffusion-weighted echo-planar MR imaging successfully visualized the parotid glands of all volunteers. In a first step, the median ADC value per person was computed. Using ROIs of 100 - 200 pixels, the mean was calculated to be 1.08 x 10 (- 3) mm (2)/sec +/- 0.12 x 10 (- 3) mm (2)/sec for both parotid glands prior to stimulation. After stimulation, the mean ADC was measured at 1.15 x 10 (- 3) mm (2)/sec +/- 0.11 x 10 (- 3) mm (2)/sec for both parotid glands. Evaluating the entire parotid gland, the ADC was 1.12 x 10 (- 3) mm (2)/sec +/- 0.08 x 10 (- 3) mm (2)/sec prior to stimulation, whereas the ADC increased to 1.18 x 10 (- 3) mm (2)/sec +/- 0.09 x 10 (- 3) mm (2)/sec after stimulation with lemon juice. For both types of measurements, the increase in ADC after stimulation proved to be significant (p < 0.001). High correlations between both measurement types were found (r >.83). CONCLUSION: Diffusion-weighted echo-planar MR imaging allows non-invasive quantification of functional changes in the parotid glands.

[Multislice CT of the pelvis: dose reduction with regard to image quality]. / Mehrzeilen-Spiral CT (MSCT) des Beckenskelettes: Dosisoptimierung unter Berücksichtigung der Bildqualität.

PURPOSE: To optimize the examination protocols of multislice CT (MSCT) of the pelvis for dose reduction with regard to image quality. MATERIALS AND METHODS: MSCT of the pelvis was performed on 5 cadaver specimens with stepwise reduction of the tube current at 140 kV (250, 200, 150, 100, 75, 50, 35, 25 mAs) and 120 kV (50, 27 mAs). The remaining scan parameters like collimation (4 x 1 mm) and table speed of 4 mm per rotation remained unchanged. Axial sections and coronal reconstructions were used to evaluate cortex, trabecular structures, subjective image quality, image noise and detail detectability (pelvis and SI joint), with evaluation performed independently by four blinded experienced radiologists on a 5-point scale. Kappa coefficient, accuracy of the observers to sort the films with regard to dose reduction and mean scores of image evaluation were determined for statistical analysis. RESULTS: The deterioration of the image quality was most pronounced for all criteria between 75 mAs and 50 mAs at 140 kV. Good results with adequate image quality were obtained for detail detectability at 50 mAs and 140 kV (effective dose [E]: 3.3 mSv) and for the remaining four criteria at 75 mAs (E: 4.9 mSv). There was a moderate agreement between the four observers (kappa coefficient: 0.27). All observers were excellent in arranging the images according to the increasing dose reduction. CONCLUSIONS: Image quality of MSCT of the pelvis appears to be acceptable at 75 mAs and 140 kV with the dose reduced to 46% of the average value of the nation-wide survey of the German Roentgen Society in 1999 for this type of examination.

[Detection of liver lesions with gadolinium-enhanced VIBE sequence in comparison with SPIO-enhanced MRI]. / Detektion von Leberläsionen mit der Gadolinium-verstärkten VIBE-Sequenz im Vergleich zur SPIO-verstärkten MRT.

PURPOSE: Detection of malignant liver lesions with gadolinium-enhanced volumetric interpolated breath-hold examination (VIBE) in comparison with SPIO-enhanced MRT (four different SPIO-enhanced T2w sequences) and histological and imaging follow-up in non-cirrhotic livers at 1.5 T. PATIENTS AND METHODS: Twenty-two patients with suspected focal liver lesions prospectively underwent a gadolinium-enhanced 3D VIBE. Four T2w sequences (HASTE sequence, fast spin-echo-sequence with and without fat-saturation, FLASH 2D gradient echo-sequence) after administration of superparamagnetic iron oxide (SPIO) served as gold standard combined with histological work-up in 17 patients and histological and imaging follow-up in five patients. The image quality was evaluated and the detectability of intrahepatic lesions was rated by the alternative free-response receiver operating characteristic (AFROC) analysis. In addition, the contrast-to-noise ratio was compared. RESULTS: Altogether 49 malignant and 35 benign liver lesions were found. Concerning the image quality, VIBE turned out to be of slightly poorer image quality than the SPIO-enhanced examination with HASTE sequence (4.95 vs. 5.0). The fast spin-echo-sequence without fat-saturation demonstrated the highest contrast-to-noise ratio. All sequences showed a comparable certainty in detecting lesion (area under the curve 0.68-0.73) and identifying malignant liver lesions. CONCLUSION: Despite the small number of patients, VIBE seems to be a comparable, inexpensive and fast method in diagnosing malignant liver lesions.

CSF-tau, CSF-Abeta1-42, ApoE-genotype and clinical parameters in the diagnosis of Alzheimer's disease: combination of CSF-tau and MMSE yields highest sensitivity and specificity.

This study evaluated the sensitivity and specificity of the cerebrospinal fluid (CSF) levels of tau-protein, amyloid-beta-peptide 1-42 (Abeta1-42), ApoE-genotype and the degree of cognitive decline as diagnostic markers for Alzheimer's disease (AD). Data was obtained from 105 AD patients and 68 controls. Median CSF-tau levels were increased (512 pg/ml vs. 145 pg/ml, p<0.001) and Abeta1-42-levels were decreased (238.5 pg/ml vs. 310 pg/ml, p<0.001) in AD patients compared to controls. A weak correlation was found between CSF-Abeta1-42 and MMSE score (r=.245). Within all subjects, a correlation of CSF-Abeta1-42 (r=-.337) and CSF-tau (r=.384) with age was found. The combination of CSF-tau levels and MMSE revealed the highest sensitivity (92%) and specificity (87%). In summary, CSF-tau was a useful biological marker to discriminate AD from normal aging, neurological and psychiatric disorders. CSF-Abeta1-42 showed no additional benefit in discriminating patients from controls but might be useful for tracking the severity of the disease.

[Investigation of the health-related quality of life after a dorso ventral stabilization of the thoracolumbar junction]. / Untersuchung der Lebensqualität nach dorsoventraler Stabilisierung von Wirbelkörperfrakturen des thorakolumbalen Ubergangs.

OBJECTIVE: Combined dorsoventral stabilization provides superior mechanical stability in the operative treatment of thoracolumbar spine fractures. Currently, there are no data available reflecting the quality of life in trauma patients following the combined procedure. The aim of this investigation was to study the health-related quality of life after dorsoventral stabilization of the thoracolumbar junction using the SF-36 Health Survey. METHODS: In order to assess the quality of life, 30 patients from a consecutive series with unstable fractures of the thoracolumbar junction were investigated in a clinical study. After posterior stabilization with an internal fixator (USS, Synthes),anterior arthrodesis was performed subsequently by autogenous iliac bone grafting in combination with osteosynthesis (MACS, Aesculap; VentroFix, Synthes). The quality of life was investigated 2 years after surgery. Additionally, plain X-rays were obtained and the degree of kyphotic deformation was measured. RESULTS: The evaluation of the data obtained from the SF-36 revealed a reduced quality of life, especially regarding the "physical functioning index", the "bodily pain index", and the "emotional functioning index". Of the patients, 42% still suffered from moderate to severe pain. Measurement of the Cobb angle showed a slight loss of correction without occurrence of a relevant kyphotic deformity. Our statistical analyses did not show any correlation between the data obtained from the SF-36 and the clinical results. Especially there was no correlation between the "bodily pain index" and the Cobb angle ( r=0.112, Spearman's rank order correlation). CONCLUSION: The patients studied here showed a reduced quality of life 2 years after dorsoventral stabilization of the thoracolumbar junction predominantly resulting in long-term pain symptoms. As these findings could not be related to the radiological results (i.e., the occurrence of a kyphotic deformation), other factors such as injury of the motion segment of the spine and the major surgical procedure have to be considered as the main reasons for the reduced quality of life. In summary, it can be concluded that the SF-36 is a suitable tool for the investigation of the postoperative outcome following dorsoventral stabilization of the thoracolumbar junction in trauma patients.

[Evaluation of TSE- and T1-3D-GRE-sequences for focal cartilage lesions in vitro in comparison to ultrahigh resolution multi-slice CT]. / Beurteilung von TSE- und T1-3D-GRE-Sequenzen bei fokalen Knorpeldefekten in vitro im Vergleich zur ultrahochauflösenden MS-CT.

PURPOSE: Evaluation of TSE- and T 1 -3D-GRE-sequences for focal cartilage lesions in vitro in comparison to ultrahigh resolution multi-slice CT. MATERIALS AND METHODS: Forty artificial cartilage lesions in ten bovine patellae were immersed in a solution of iodinated contrast medium and assessed with ultrahigh resolution multi-slice CT. Fat-suppressed TSE images with intermediate- and T 2 -weighting at a slice thickness of 2, 3 and 4 mm as well as fat-suppressed T 1 -weighted 3D-FLASH images with an effective slice thickness of 1, 2 and 3 mm were acquired at 1.5 T. After adding Gd-DTPA to the saline solution containing the patellae, the T 1 -weighted 3D-FLASH imaging was repeated. RESULTS: All cartilage lesions were visualised and graded with ultrahigh resolution multi-slice CT. The TSE images had a higher sensitivity and a higher inter- and intraobserver kappa compared to the FLASH-sequences (TSE: 70 - 95 %; 0.82 - 0.83; 0.85 - 0.9; FLASH: 57.5 - 85 %; 0.53 - 0.72; 0.73 - 0.82, respectively). An increase in slice thickness decreased the sensitivity, whereby deep lesions were even reliably depicted on TSE images at a slice thickness of 3 and 4 mm. Adding Gd-DTPA to the saline solution increased the sensitivity by 10 % with no detectable advantage over the T 2 -weighted TSE images. CONCLUSION: TSE sequences and application of Gd-DTPA seemed to be superior to T 1 -weighted 3D-FLASH sequences without Gd-DTPA in the detection of focal cartilage lesions. The ultrahigh resolution multi-slice CT can serve as in vitro reference standard for focal cartilage lesions.

Umbilical vein blood volume flow rate and umbilical artery pulsatility as 'venous-arterial index' in the prediction of neonatal compromise.

OBJECTIVE: To assess the diagnostic power of the umbilical venous-arterial index (VAI) for the prediction of poor fetal outcome. SUBJECTS AND METHODS: This was a retrospective, cross-sectional clinical study in which normalized umbilical vein blood volume flow rate (nUV) (mL/min/kg estimated body weight), umbilical artery pulsatility index (UAPI), the newly developed VAI (nUV/UAPI), and the uterine artery resistance index (UTRI) were determined in 85 fetuses once (17-41 gestational weeks) during pregnancy using standard ultrasound Doppler equipment. A risk score based on umbilical blood pH, 1-min Apgar score, birth weight, duration of gestation, type of respiratory support, and referral to the pediatric department was constructed, and fetuses were assigned to a control or a pathological group accordingly. Logistic regression and analysis of fitted receiver-operating characteristics curves were performed to evaluate the diagnostic power of nUV, UAPI, UTRI, and VAI. RESULTS: The incidence of compromised neonates was 17.6%. The area under the receiver-operating characteristics curve was larger for VAI than for UTRI or for UAPI (P < 0.002). At a cut-off value of 100 mL/min/kg, the sensitivity of VAI to predict poor neonatal outcome was 85% with a 15% false-positive rate. CONCLUSION: Determination of the VAI has a greater diagnostic power to predict poor fetal outcome than the pulsatility index in the umbilical artery or the resistance index in the uterine artery.

Effect of intravenous thrombolysis on MRI parameters and functional outcome in acute stroke <6 hours.

BACKGROUND AND PURPOSE: The goals of this study were to examine MRI baseline characteristics of patients with acute ischemic stroke (AIS) and to study the influence of intravenous tissue plasminogen activator (tPA) on MR parameters and functional outcome using a multicenter approach. METHODS: In this open-label, nonrandomized study of AIS patients with suspected anterior circulation stroke, subjects received a multiparametric stroke MRI protocol (diffusion- and perfusion-weighted imaging and MR angiography) within 6 hours after symptom onset and on follow-up. Patients were treated either with tPA (thrombolysis group) or conservatively (no thrombolysis group). Functional outcome was assessed on day 90 (modified Rankin Score; mRS). RESULTS: We enrolled 139 AIS patients (no thrombolysis group, n=63; thrombolysis group, n=76). Patients treated with tPA were more severely affected (National Institutes of Health Stroke Scale score, 10 versus 13; P=0.002). Recanalization rates were higher in the thrombolysis group (Thrombolysis in Myocardial Infarction criteria 1 through 3 on day 1; 66.2% versus 32.7%; P<0.001). Proximal vessel occlusions resulted in larger infarct volumes and worse outcome (P=0.02). Thrombolysis was associated with a better outcome regardless of the time point of tPA treatment (< or =3 hours or 3 to 6 hours) (univariate analysis: mRS < or =2, P=0.017; mRS < or =1, P=0.023). Age (P=0.003), thrombolytic therapy at 0 to 6 hours (P=0.01), recanalization (P=0.016), lesion volume on day 7 (P=0.001), and initial National Institutes of Health Stroke Scale score (P=0.001) affected functional outcome (mRS on day 90) positively (multivariate analysis). The time point of tPA therapy affected the recanalization rate (P=0.024) but not final infarct volume. CONCLUSIONS: In this pilot study, tPA therapy had a beneficial effect on vessel recanalization and functional outcome. Multiparametric MRI delineates tissue at risk of infarction in AIS patients, which may be helpful for the selection of patients for tPA therapy. tPA therapy appeared safe and effective beyond a 3-hour time window. This study delivers the rationale for a randomized, MR-based tPA trial.

TNFalpha, interleukin-10 and interleukin-18 expression in cells of the bronchoalveolar lavage in patients with pulmonary complications following bone marrow or peripheral stem cell transplantation: a preliminary study.

Pulmonary complications pose a major clinical problem after bone marrow transplantation (BMT) or peripheral blood stem cell transplantation (PBSCT). The underlying pathophysiological mechanisms are under investigation. Twenty patients with infectious or non-infectious pulmonary complications after BMT or PBSCT underwent bronchoalveolar lavage (BAL) and tumor necrosis factor-alpha (TNFalpha), interleukin-10 (IL-10) and interleukin-18 (IL-18) mRNA expression was determined in BAL cells in comparison to 11 healthy volunteers. Patients were divided into two groups (infectious pneumonia, n = 14 or idiopathic pneumonia syndrome (IPS)/bronchiolitis obliterans (BO), n = 6). TNFalpha expression was significantly increased in both patient groups compared to the control (0.40 +/- 0.07 and 0.39 +/- 0.09 vs 0.15 +/- 0.05; P < 0.05; semiquantitative PCR analysis; mean +/- s.e.m.). IL-10 expression was significantly elevated the group of patients with infectious pneumonia in comparison to normal controls (0.15 +/- 0.06 vs 0.01 +/- 0.01; P < 0.05) but not in patients with IPS/BO (0.05 +/- 0.04; P > 0.05). However, IL-10 was not expressed in BAL cells of all patients and control individuals. IL-18 expression was significantly decreased in the both patient groups (1.47 +/- 0.24 and 1.79 +/- 0.63) in comparison to the control group (4.29 +/- 0.77; P < 0.05). Survival analysis showed a significant association between elevation of TNFalpha and poor prognosis (P < 0.05). These results highlight the immunoregulatory disturbances in the lungs after BMT/PBSCT.

[Value of triple phase helical CT for the detection of hepatocellular carcinoma in cirrhotic liver]. / Stellenwert der dreiphasischen Spiral-CT in der Detektion des hepatozellulären Karzinoms bei Leberzirrhose.

PURPOSE: Purpose of this study was to determine the value of the delayed-phase (DP) of helical CT in the detection of hepatocellular carcinoma (HCC) in cirrhotic liver in comparison to the arterial phase (AP) and the portal-venous phase (PP). MATERIAL AND METHODS: 51 patients with liver cirrhosis and suspected HCC were examined by triple-phase helical-CT (THCT). Images were standardized and obtained 20 seconds - AP, 60 - 70 seconds - PP, and 300 seconds - DP after injection of 140 ml of intravenous iodinated contrast material. Pictures were reviewed by two experienced radiologists for typical intrahepatic lesions. First, each single phase of contrast distribution were seen separately. Then all contrast phases were reviewed together. RESULTS: In 17 patients 49 typical lesions were found, histological work-up was performed, whereas in 34 patients clinical follow-up of at least 6 months was obtained. The arterial phase (AP) itself depicted 55 % of these lesions, whereas the portal-venous phase (PP) depicted 57 % and the delayed phase 78 %. DP showed a significantly higher detection rate in comparison to the PP (p = 0.008). By performing a biphasic helical CT 40 lesions would have been detected with AP and PP, whereas all 49 lesions would have been visualised by combining AP and DP. This means a significantly higher detection rate for AP/DP instead of using AP/PP (p = 0.031). CONCLUSION: Additionally to the AP and PP, a delayed phase should be performed when cirrhosis is present. Even though AP and DP depicted all HCC's in this study, the PP provides undispensable additional information, so that, in our opinion, a THCT should be given preference when HCC is suspected.

Enhanced platelet aggregation with TRAP-6 and collagen in platelet aggregometry in patients with venous thromboembolism.

The role of platelet hyperaggregability as a possible risk factor for venous thromboembolism is not well defined. Some authors described enhanced maximal platelet aggregation in platelet aggregometry as a contributing factor for arterial and venous thrombosis. This syndrome has been termed "sticky-platelet syndrome" (SPS). The diagnosis of SPS is based on the demonstration of platelet hyperaggregability in aggregometry after stimulation with epinephrine (EPI) and/or adenosine diphosphate (ADP). We investigated platelet hyperaggregability in platelet-rich plasma (PRP) of patients (n = 34) with unexplained venous thromboembolism in comparison to healthy individuals (n = 53). For analysis, platelet aggregometry was performed and the influence of epinephrine, adenosine diphosphate, collagen (Coll) and thrombin receptor-activated peptide (TRAP-6) as agonist were determined. Compared to the control group, patients with venous thromboembolism showed an enhanced maximal platelet aggregation with low concentrations of TRAP-6 (2 microM) and collagen (0.05 microM). In contrast, we could not detect an increased platelet aggregation with EPI or ADP. Our results indicate that platelet hyperaggregability may represent an independent risk factor in patients with otherwise unexplained venous thromboembolism. In our study, low concentrations of TRAP-6 and collagen are superior to EPI and ADP to define platelet hyperreactivity in platelet aggregometry.

[MRI in the preoperative diagnosis of chronic sinusitis: comparison with CT]. / MRT in der präoperativen Diagnostik der chronischen Sinusitis im Vergleich mit der CT.

PURPOSE: To determine the value of MRI in the preoperative evaluation of chronic paranasal sinusitis and to compare the results with CT and intraoperative findings. METHOD/MATERIALS: 42 patients with clinical signs of chronic paranasal sinusitis underwent MRI after CT evaluation on one day, with subsequent functional endoscopic sinus surgery on the next day. Coronary CT was obtained with 5-mm slices and table-feed in the prone position, while MRI was performed in the supine position with coronary T2-TSE + pd and coronary and transverse HASTE, each with 5-mm slice thickness. Aquisition time in MRI was less than 8 minutes. Two radiologists reviewed the CT and MRI scans for signs of sinusitis and detection of anatomical landmarks. The results were correlated with the intraoperative findings. RESULTS: MRI offered no artifacts of dental work and showed more often high quality pictures than CT. CT and MRI demonstrated a good correlation in the detection of mucosal pathologies (kappa = 0.46-0.87) and anatomic variants (kappa = 0.55-0.86). All important anatomical structures could be evaluated sufficiently with MRI for preoperative management. Both diagnostic tools showed an unsatisfactory correlation with intraoperative findings in the ethmoidal complex and maxillary sinus (tau = -0.08-0.3). CONCLUSIONS: MRI is a fast and reliable alternative to preoperative CT in examining paranasal sinuses and offers a good visualization of mucosal changes. CT and MRI both give an unreliable representation of the ethmoidal complex.

20-fold increase in risk of lamivudine resistance in hepatitis B virus subtype adw.

We investigated subtype-dependent development of lamivudine resistance in hepatitis B virus (HBV) longitudinally in 26 consecutive patients (13 adw and 13 ayw carriers) during antiviral treatment of chronic hepatitis B. Lamivudine resistance developed in seven adw carriers and one ayw carrier. Risk of lamivudine resistance was significantly higher for adw carriers than for ayw carriers (p=0.03). We believe that the adw subtype of HBV is associated with a high risk of lamivudine resistance, which might be linked to simultaneous changes of the HBsAg that occurs with the emergence of resistance.

[Hypothermia in patients with burn injuries: influence of prehospital treatment]. / Hypothermie bei brandverletzten Patienten--Einflüsse der präklinischen Behandlung.

Hypothermia following pre-hospital treatment of burn patients is a common risk with increasing lethality. Soon after admission to our burn unit, the body temperature of 212 adult patients with more than 5% total body surface area burned was documented. We found no influence of the time of pre-hospital care and cold-water treatment alone on the body temperature. If the patients were not anesthetized, the initial temperature was normal. Only the anesthetized and artificial ventilated patients were hypothermic. We conclude that hypothermia is not a problem of the non-anesthetized and cold-water-treated patient. However, all anesthetized patients must be carefully treated to avoid hypothermia as an important complication in the pre-hospital management.