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Biomedical subjects

Bodo Kress

Publications and source records attributed to Bodo Kress.

17 recordsLinked to original sources
PubMed2006

Age- and tooth-related pulp cavity signal intensity changes in healthy teeth: a comparative magnetic resonance imaging analysis.

OBJECTIVE: To determine if it is possible to measure age-related pulp cavity signal intensity changes by using magnetic resonance imaging (MRI). STUDY DESIGN: Dental pulp cavity signal intensities were assessed in 92 test subjects on the basis of MRI signal intensity measurements at freely defined regions of interest by using T1 gradient echo sequences before and after contrast-agent administration. Relative signal intensity differences were calculated and provided the basis for age- and tooth-related comparisons. RESULTS: Significant signal intensity differences were noted between the oldest (born between 1930 and 1959) and the youngest (born after 1980) test subjects and the other groups (P < .05). In addition, the first molars showed significantly lower signal intensity differences than the second molars (P < .05). CONCLUSION: Magnetic resonance imaging can be used to determine pulp cavity signal-intensity changes with age.

Age Factors↗
PubMed2006

Assessment of the reliability and validity of panoramic imaging for assessment of mandibular condyle morphology using both MRI and clinical examination as the gold standard.

OBJECTIVES: The purpose of this study was to evaluate both reliability and validity of the assessment of the shape of the mandibular condyle in panoramic images of the TMJ. STUDY DESIGN: Forty subjects were included and were examined according to the Research Diagnostic Criteria for Temporomandibular Disorders. Panoramic radiographs (PRs) and magnetic resonance images (MRIs) were completed for all subjects. Both MRIs and PRs were rated by raters blinded to the clinical diagnosis. Kappa statistics were used to compare the results of the raters of the PRs. Additionally, the specificity and the sensitivity of the PRs were calculated for 2 scenarios: one with MRI and the other with clinical findings as the gold standard. RESULTS: The sensitivity was 0.94 (specificity = 0.45) for the assumption that MRI is the gold standard and 0.86 (specificity = 0.49) for the assumption that the clinical examination is the gold standard. For reliability, the results for kappa ranged from 0.06 to 0.327. CONCLUSION: It can be concluded that PRs are not a reliable method of accurately judging the shape of the mandibular condyle.

Adolescent↗
PubMed2006

Volumetric measurement of the pontomesencephalic cistern in patients with trigeminal neuralgia and healthy controls.

OBJECTIVE: Most so-called idiopathic trigeminal neuralgias (TN) are caused by neurovascular compression. Does the size of the cerebellopontine cistern play a role in favoring a neurovascular conflict? The aim of this prospective study was to measure the volume of the parapontine cistern in patients with idiopathic TN and to perform a comparison with healthy controls. METHODS: In 25 patients with unilateral idiopathic TN and 17 healthy participants, high-resolution 1.5-T magnetic resonance imaging scans of the parapontine region and the trigeminal nerve were performed. A coronal T2-weighted, true fast imaging steady-state precession sequence with a slice thickness of 0.9 mm was used to define the surrounding cerebrospinal fluid space from the trigeminal root entry zone to Meckel's cave. The volume of the pontomesencephalic cistern was calculated using a standardized method. RESULTS: The mean difference of the volume of the affected and opposite side was 13% in patients with TN. In all patients, a significantly smaller volume of the cistern was found on the affected side (P < 0.01). Healthy controls showed a mean volumetric side difference of 9%, which was not significant (P > 0.05). CONCLUSION: High-resolution magnetic resonance imaging scans are able to demonstrate significant volumetric differences of the pontomesencephalic cistern in patients with unilateral TN. A smaller cistern may be correlated with the occurrence of a neurovascular compression, and these findings support the neurovascular compression theory in idiopathic TN.

Adult↗
PubMed2005

Prolonged low-dose intravenous thrombolysis in a stroke patient with distal basilar thrombus.

BACKGROUND AND PURPOSE: Patients with high-grade basilar artery stenosis secondary to thromboembolism are at high risk of developing subsequent vessel occlusion. Optimal medical management of this condition is unclear. SUMMARY OF CASE: We present a patient with a small subacute brain stem infarction and filiform distal basilar residual lumen attributable to arterioarterial or cardiogenic embolism. Beginning 3 days after symptom onset, low-dose intravenous thrombolysis with 0.125 mg/kg recombinant tissue plasminogen activator was continuously infused for 48 hours. Follow-up magnetic resonance angiography revealed complete resolution of the embolus. No further cerebral ischemic episodes occurred during 3-month follow-up, and the basilar artery remained patent. CONCLUSIONS: Our observation suggests a potential for prolonged low-dose intravenous thrombolysis in basilar artery embolism, but further data are needed to judge the effectiveness and risk of this intervention.

Aged↗
PubMed2005

Time-efficient localization of the human secondary somatosensory cortex by functional magnetic resonance imaging.

Standardized, robust and time-efficient localization of the human secondary somatosensory cortex (S2) is a challenge in clinical blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI). A fully automated tactile stimulation was optimized in seven right-handed volunteers at 1.5 T for minimum scan time, high BOLD signals and robust localization of S2 by systematically varying the applied block-design. All volunteers had six different fMRI measurements of five stimulation-baseline-cycles (sbc) each with equal block duration that was changed between the measurements from 6 s to 30 s. Additional data sets of 4, 3 and 2 cycles were generated post hoc resulting in a total of 168 data sets that were evaluated individually for BOLD-signal intensity (dS%), correlation to the hemodynamic reference function (r) and Euclidean coordinates (x, y, z). Using different block-designs the S2 activation was highly variable regarding the localization rate (lr), the hemispheric symmetry and the BOLD-signals. The protocol with 3 cycles, a block duration (dp) of 15 s and a total scan time (dt) of 105 s most robustly localized S2 (contralateral: lr=71.4%, r=0.65, dS=1.01%; ipsilateral: lr=100%, r=0.6, dS=1.14%) whereas the most time-efficient protocol to localize SI (sbc=5, dp=6 s, dt=66 s) provided no robust localization of S2. Compared to other published fMRI protocols a scan time reduction up to 86% was achieved.

Adult↗
PubMed2005

Artefacts in magnetic resonance imaging caused by dental material.

A common problem in computer tomography (CT) based imaging of the oral cavity is artefacts caused by dental restorations. The aim of this study was to investigate whether magnetic resonance imaging (MRI) of the oral cavity would be less affected than CT by artefacts caused by typical dental restorative alloys. In order to assess the extent of artefact generation, corresponding MRI scans of the same anatomic region with and without dental metal restorations were matched using a stereotactic frame. MRI imaging of the oral and maxillofacial region could be performed without reduction of the image quality by metallic dental restorations made from titanium, gold or amalgam. Dental restorations made from titanium, gold or amalgam did not reduce the image quality of the MRI sequence used in imaging of the oral and maxillofacial region for dental implant planning. In this respect MRI is superior to CT in implant planning.

Animals↗
PubMed2005

MRI volumetry for the preoperative diagnosis of trigeminal neuralgia.

To assess whether quantitative measuring methods can help improve the reliability of MRI-based evaluations of the pathological role of a neurovascular conflict between an artery and the trigeminal nerve. In a prospective study, magnetic resonance images were obtained from 62 patients with unilateral facial pain and 50 healthy test subjects. In coronal T1- and T2-weighted sequences volume measurements were performed by regions of interest and compared intraindividually (healthy versus affected side in the patient populations and right versus left side in the group of test subjects) and on the basis of the different clinical pictures (t test for dependent and independent samples, p<0.05). In patients with trigeminal neuralgia, the affected nerve showed a smaller volume than the trigeminal nerve on the healthy side (p<0.001). Such a volume difference was noted neither in the other patients nor in the healthy test subjects. Quantitative MRI measurements allow a pathological neurovascular conflict to be distinguished from a nonpathological condition where an artery is in close proximity to the trigeminal nerve. The measured volume difference between the healthy and the affected nerve in patients with neuralgia is indicative of trigeminal nerve atrophy resulting from damage to the nerve.

Adult↗
PubMed2005

Psychosocial behaviour and health care utilization in patients suffering from temporomandibular disorders diagnosed on the basis of clinical findings and MRI examination.

UNLABELLED: The aim of this study was to evaluate psychosocial behaviour and differences in health care utilization between subgroups of patients suffering from temporomandibular disorders, using both clinical examination and magnetic resonance imaging (MRI). MATERIALS AND METHODS: 70 patients were examined according to the research diagnostic criteria for temporomandibular disorders (RDC/TMD), and were divided into groups according to their clinical diagnoses. MRIs were acquired and joint-related RDC/TMD diagnoses were modified on the basis of MRI findings. Group I suffered from joint pathology, group II from myofascial pain and group III from a combination. Non-parametric statistics were used to reveal group-related differences in psychosocial and behavioural aspects. Differences in group assignment based on clinical and MRI examination were assessed (kappa statistics). RESULTS: MRI findings led to group assignments that were different from clinical assignments (k = 0.3). For both types of assignment, patients with myofascial pain displayed higher somatization scores, used more splints and consulted more physicians. For clinical assignment only, depression scores were higher in the myofascial pain group. For MRI based assignment, sex differences were significant between groups I and III. CONCLUSION: Somatization-specific behaviour is more widespread in patients suffering from exclusively myofascial pain than in patients presenting joint pathology. Inconsistencies in differences of other psychosocial variables between groups of TMD patients seem to be related to differences in group assignment either with or without objective information on joint pathology.

Adult↗
PubMed2005

Temporomandibular joint disk position assessed at coronal MR imaging in asymptomatic volunteers.

PURPOSE: To assess the normal position of the temporomandibular joint (TMJ) disk relative to the condyle by using coronal magnetic resonance (MR) imaging in asymptomatic volunteers. MATERIALS AND METHODS: This study was approved by the review committee for human research, and all subjects signed an informed consent form. Thirty symptom-free volunteers without histories of TMJ disorders underwent standardized clinical examinations. Afterward, bilateral sagittal oblique and coronal oblique MR images were acquired with the patient's mouth opened and closed. The coronal oblique opened- and closed-mouth images were analyzed by using computer software. The medial and lateral edges of both the TMJ disk and the condyle were marked for these imaging examinations by using the section through the posterior 3 mm of the disk. To eliminate the effect of different magnifications and/or distortions, the distance between these points was measured automatically and divided by the largest mediolateral dimensions of the condyle. To assess the reliability of the measurements, four observers evaluated the position of the disk in the coronal plane. To assess the changes in position of the posterior 3 mm of the disk in the coronal plane in the closed- and opened-mouth positions, the Wilcoxon signed rank test for matched pairs was used. Interobserver measurement reliability was evaluated by using interclass correlation coefficients (ICCs). RESULTS: Analysis of the coronal closed-mouth disk position revealed a medial position of the TMJ disk relative to the condyle in 11 (21%) of 52 analyzed joints. In the opened-mouth position, the medial location of the disk was more frequent: 29 (85%) of 34 analyzed joints exhibited a medial position of the disk relative to the condyle in this plane. This increasingly medial position of the disk was statistically significant (P < or = .001). Measurement reliability assessment revealed sufficient results (ICC > or = 0.7). CONCLUSION: At both closed- and opened-mouth MR imaging, a medially located TMJ disk seems to be within the normal range of variation. The disk seems to shift even more medially when the mouth is opened.

Adult↗
PubMed2005

MR imaging-based volumetry in patients with early-treated phenylketonuria.

BACKGROUND AND PURPOSE: Our purpose was to specify the most severely affected brain structures in early treated phenylketonuria regarding volume loss and establish possible correlations between volume loss and plasma levels of phenylalanine (Phe). METHODS: In 31 patients with early treated phenylketonuria and in 27 healthy volunteers, we acquired volumetric MR imaging data. Serum Phe concentrations at different times were measured as well. Semiautomatic volumetric postprocessing of the cerebellum, cerebrum (supratentorial brain tissue), hippocampus, intracranial volume, lateral ventricles, nucleus caudatus, nucleus lentiformis, pons, and thalamus, as well as the two-dimensional extension of the corpus callosum, was performed using the software BRAINS2. For each separate brain structure, the relative differences between the normal and the phenylketonuria group (delta(rel)) were calculated. RESULTS: The cerebrum, corpus callosum, hippocampus, intracranial volume, and pons were significantly smaller in patients with phenylketonuria than in healthy patients. The volume of the lateral ventricles was significantly larger in patients with phenylketonuria than in healthy ones. The most severely affected structures were the pons (delta(rel) = 16%), hippocampus (delta(rel) = 14.5%), cerebrum (delta(rel) = 13%), and corpus callosum (delta(rel) = 10%). No significant differences were found for the basal ganglia, cerebellum, and thalamus. There were no significant correlations found between the volume of any of the different brain structures and the metabolic parameters. CONCLUSION: The most severely affected brain structures in early-treated patients with phenylketonuria regarding volume loss are the cerebrum, corpus callosum, hippocampus, and pons.

Adult↗
PubMed2004

Fully automated localization of the human primary somatosensory cortex in one minute by functional magnetic resonance imaging.

A clinical functional magnetic resonance imaging (fMRI) protocol based on a fully automated tactile stimulation was optimized in 10 right-handed volunteers at 1.5 T for minimum scan time, high BOLD-signals and robust localization of the primary somatosensory cortex (S1) by systematically varying the applied block design. All volunteers had six different fMRI measurements of 5 stimulation/baseline cycles each with equal block duration that was changed between the measurements from 6 to 30 s. Data sets of 4, 3 and 2 cycles were generated post hoc resulting in a total of 240 data sets that were evaluated individually for BOLD-signal intensity (dS%), correlation to the hemodynamic reference function (r) and Euclidean coordinates (x, y, z). The protocol with 5 cycles, a block duration of 6 s and a total scan time of 66 s provided the best BOLD-signal characteristics (dS% = 1.15, r = 0.78). Compared to the mean scan time of other clinical fMRI protocols (174 s) a reduction of 62% was achieved.

Adult↗
PubMed2004

Temporomandibular joint pathosis in patients with myofascial pain: a comparative analysis of magnetic resonance imaging and a clinical examination based on a specific set of criteria.

OBJECTIVE: We sought to determine the prevalence of joint diseases in patients with either of 2 forms of myofascial pain (with and without limited mouth opening) and to verify the accuracy of temporomandibular joint-related clinical diagnoses through the use of magnetic resonance imaging (MRI). STUDY DESIGN: On the basis of the results of a clinical examination carried out according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), 61 patients were divided into 2 subgroups. The first group consisted of 36 patients who had myofascial pain with limited mouth opening (MPLO), whereas the other 25 patients were diagnosed with myofascial pain without limited mouth opening. MRI was carried out on all patients. The clinical joint-related diagnoses from RDC/TMD were compared with MRI results. RESULTS: Patients with MPLO often had joint diseases that were not detected by means of a clinical examination alone. The kappa statistic was used to compare MRI and clinical diagnoses, confirming poor agreement in patients with MPLO (kappa=0.13) and acceptable agreement in patients with myofascial pain without limited mouth opening (kappa=0.72). CONCLUSION: Restricted mandibular mobility is frequently associated with temporomandibular joint diseases that were not identified during a clinical examination. Therefore, an adaptation of the classification scheme used for the RDC/TMDs may result in the improvement of the sensitivity of clinical joint-related diagnoses, especially in patients with MPLO.

Adult↗
PubMed2003

Bell palsy: quantitative analysis of MR imaging data as a method of predicting outcome.

PURPOSE: To assess the prognostic value of quantitative analyses of region-of-interest (ROI) magnetic resonance (MR) imaging data in patients with acute facial nerve palsy. MATERIALS AND METHODS: In a single-blinded study, MR images were obtained in 39 patients (32 men and seven women; age range, 18-75 years; average age, 37.9 years) with acute facial nerve palsy. MR images were obtained before the 6th day of illness, on the first day of standard inpatient treatment with high-dose steroids. Signal intensity (SI) was measured at ROIs in each of five segments (internal auditory canal [IAC]; geniculate ganglion; and labyrinth, tympanic, and mastoid segments) of the intratemporal portion of the facial nerve and quantitatively analyzed. The SI measurements in the five segments were summed and divided by 100 to provide a basis for establishing an MR imaging index. SI increases and MR imaging indexes were compared with available clinical findings and electrophysiologic data. RESULTS: Data for all 39 patients could be analyzed. The MR imaging index was significantly higher in patients with poor outcomes than in patients with favorable outcomes (specificity, 97%; sensitivity, 75%; P <.01). The SI increases in the IAC were significantly different between patients who progressed to full recovery (mean increase, 45.7%) and patients who developed chronic facial paralysis (mean increase, 156.5%) (sensitivity, 100%; specificity, 97%; P <.001). The results of differentiating between patients with good and those with poor outcomes on the basis of SI measurements in the IAC were found to be in complete agreement with electrophysiologic data. CONCLUSION: Quantitative analysis of ROI MR imaging data is a valid method of predicting the outcome of acute facial nerve palsy during the first days after onset of symptoms and thus at a time when it is not yet possible to obtain valuable prognostic information by using electrophysiologic methods.

Action Potentials↗
PubMed2003

Robust localization and lateralization of human language function: an optimized clinical functional magnetic resonance imaging protocol.

An optimized clinical functional magnetic resonance imaging (fMRI) protocol with a total scanning time of 8 min is presented that localizes Broca's and Wernicke's areas robustly and determines hemispheric dominance. Language function was visualized using two different sentence generation (SG) and word generation (WG) tasks. Block designed blood oxygenation level dependent (BOLD) fMRI was applied in 14 right-handed volunteers at 1.5 T during visual stimulation. BOLD-clusters were assessed individually for anatomical localization. Reference data are provided for the maximum correlation of the measured BOLD-signal time course to the applied reference function (r(max)), for the maximum relative signal change (dS%), cluster size and Euklidian coordinates of Broca and Wernicke activation and of the anatomical homologues in the right hemispheres. Statistical means and a lateralization index (LI) were calculated. Broca activation focussed on the inferior frontal gyrus, and Wernicke activation on the superior temporal, supramarginal or middle temporal gyri. Mean BOLD-signals for Broca ranged from 1.53% (SG) to 2.56% (WG), and for Wernicke from 1.47% (SG) to 1.80% (WG). LI indicated left language dominance. The data provided further evidence for the high anatomical variability of language areas, which underlined the relevance of an individual language localization and lateralization prior to brain surgery.

Adult↗
PubMedDate not supplied

Prediction of TMJ arthralgia according to clinical diagnosis and MRI findings.

PURPOSE: The aim of this study was to investigate the ability of clinical and magnetic resonance imaging (MRI) diagnoses to predict pain in the temporomandibular joint (TMJ). MATERIALS AND METHODS: One hundred forty-nine patients were examined by 2 calibrated examiners in strict accordance with the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). All patients who presented with a defined clinical RDC/TMD diagnosis were included and underwent bilateral coronal and sagittal MRI of the TMJ. Two raters blinded to the clinical diagnosis interpreted the MRI scans for TMJ pathology. The results were tested against the clinical diagnosis according to the RDC/TMD, including pain-related disability and psychosocial status, for associations to TMJ arthralgia using logistic regression analysis (GENMOD procedure, P < .05). RESULTS: MRI-depicted anatomic changes, such as joint effusions, disc displacement, and osteoarthrosis, were not significantly correlated with the presence of pain in the TMJ. However, a significant relationship between pain on palpation of the masseter muscle origin (P = .0050) and psychosocial factors (P = .0452) and pain in the TMJ was demonstrated. CONCLUSIONS: Pain in the TMJ caused by the anatomic proximity of the muscle masseter origin and the lateral TMJ pole and the possible existence of trigger points in the musculature may lead to a false-positive or a false-negative diagnosis of arthralgia. Additionally, clinicians must consider the psychosocial aspects of pain in ideal treatment planning.

Adolescent↗