Search PubMed⌕ Search

Biomedical subjects

B Freigang

Publications and source records attributed to B Freigang.

At least 19 recordsLinked to original sources
PubMed2001

[Virtual rendering techniques in otologic imaging].

UNLABELLED: Virtual postprocessing techniques combine the advantages of condensing the large amounts of data provided by high-resolution (HR) cross-sectional imaging modalities with those of three-dimensional (3D) imaging. The techniques and indications for virtual representations in imaging of the middle ear (ME), internal ear (IE), and cerebellopontine angle (CPA) are presented together with practical examples. MATERIAL AND METHODS: HR data sets acquired by computed tomography (CT) and magnetic resonance imaging (MRI) in patients with ME, IE, and CPA pathologies were transferred to a workstation via an internal network to generate endo- or extraluminal 3D views by means of the volume rendering technique (VRT). The source data were acquired using scanners and imaging protocols with the highest resolution available at present: a multislice spiral CT (MSCT) with a slice thickness of 0.5 mm and a reconstruction increment of 0.2 mm and a 3D CISS sequence with a slice thickness of 0.5 mm for MRI. RESULTS: Virtual endoscopy was superior to cross-sectional images for assessing ME pathologies like dysplasia, postoperative changes, and destructive bone processes with extensive soft-tissue involvement; fibrous obliterations of the internal ear and labyrinthine dysplasia were depicted with a superior image quality on 3D renderings compared to conventional reconstruction techniques. Virtual endoscopy of the CPA and external acoustic meatus (EAM) was helpful in detecting and visualizing neurovascular conflicts and in assigning small intrameatal tumors to components of the acousticofacial bundle. A common feature of all applications was that the large numbers of source images could be reduced to a few 3D reconstructions for documentation and optimized communication of the findings between the radiologist and otologist. CONCLUSION: Virtual rendering makes an important contribution towards establishing, presenting, and documenting the findings when certain otologic pathologies have to be assessed. It can be used for routine imaging and allows for more efficient handling of the large amounts of imaging data generated by high-resolution cross-sectional imaging modalities.

Cerebellopontine Angle↗
PubMed2001

Visualization of inner ear dysplasias in patients with sensorineural hearing loss.

PURPOSE: We evaluated a data acquisition and post-processing protocol for inner ear (IE) assessment by MR imaging in patients, suffering from various labyrinth malformations. MATERIAL AND METHODS: MR IE studies of 158 consecutive patients (316 IEs) suffering from sensorineural hearing loss without evidence of an acoustic neurinoma were reviewed for pathologies of the IE and internal acoustic meatus. High-resolution MR data of all abnormal IE studies (n=45) were post-processed to previously standardized 3D volume rendered (VR) reconstructions. RESULTS: In 9 patients (5.7%) the following IE dysplasias were detected: malformation of the cochlea (6 IEs), vestibulum (4 IEs), semicircular canals (12 IEs) and vestibular aqueduct/endolymphatic sac (10 IEs). One patient showed evidence of an aplasia of the vestibulocochlear nerve. In 4 patients multiple IE dysplasias were encountered. Comprehensive 3D visualization of all labyrinthine dysplasias was achieved by the use of two VR reconstructions. The overall time for bilateral IE assessment amounted to 30-35 min. CONCLUSION: The imaging protocol allows for rapid and comprehensive visualization of various IE dysplasias, based on a limited number of VR reconstructions.

Adolescent↗
PubMed2001

Virtual endoscopy of the tympanic cavity based on high-resolution multislice computed tomographic data.

OBJECTIVE: This study was designed to assess the value of high-resolution multislice computed tomography (MSCT) data of the petrous bone for the virtual endoscopic visualization of the tympanic cavity. BACKGROUND: The recently introduced MSCT technology has improved spatial resolution in the z axis as well as scan speed in computed tomography. Three-dimensional rendering of high-resolution MSCT data of the petrous bone may be expected to provide endoluminal views of superior image quality, thus competing with transtympanic endoscopy (otoendoscopy). SETTING: This study was conducted at a university teaching hospital. MATERIALS AND METHODS: Cadaveric phantom studies in a MSCT scanner were performed to define a data acquisition protocol, combining adequate detail resolution with low tube current. Subsequently, the cadaveric phantom underwent otoendoscopy. The postprocessing parameters of the three-dimensional rendering protocol were chosen to produce views closely resembling the corresponding otoendoscopic images. High-resolution data from 18 patients with pathologic conditions of the middle ear, as suggested by clinical findings and assessment of cross-sectional data, were postprocessed using the volume rendering technique to generate standardized virtual endoscopic views. A total of 36 virtual endoscopic scans of the tympanic cavity were generated. RESULTS: With regard to intermediate and high-density structures, virtual endoscopic images, based on MSCT data, yielded endoluminal views closely resembling corresponding otoendoscopic views. Virtual endoscopy seems useful for imaging ossicular pathologic conditions such as dysplasia and chain disruption as well as for assessing patient status before and after otosurgery. CONCLUSION: MSCT data sets allow for generating virtual endoscopic views closely resembling otoendoscopic images. The technique is especially useful when ossicular pathologic changes are present as well as for preoperative and postoperative imaging of otologic procedures.

Endoscopy↗
PubMed2000

[Second carcinomas in cancers of the mouth cavity, pharynx and larynx. Clinical, histopathologic and cell kinetic findings].

BACKGROUND: The mortality because of malicious tumours of the oral cavity, of the pharynx and of the larynx has considerably increased in the Federal Republic of Germany during the last two decades. The prognosis not only shows a high ratio of recidivations and formation of metastases, but also a typical field canceration. There is a high rate of incidence of multiple primary, resp. secondary tumours that may occur synchronously or metachronously. Up to now we have learnt only little about the mechanisms concerning the development of tumours and their spread on the cellular molecular level. METHOD: The subject of the present retrospective study was the analysis of patients suffering from an epithelioma of the oral cavity, the pharynx and the larynx and the following secondary carcinomatas. The control group were patients suffering from primary tumours of the same location and subsequent recidivation or metachronous metastasis. By determination of the degree of malignity and keratinisation of the DNA ploidy, of the immunohistological expression of p53 and the immunohistological proliferation marker MIB1 conclusions had to be drawn with regard to the biological behaviour of tumours. RESULTS: The evaluation of the clinical parameters of the 122 patients on the whole revealed a clear increase of new disease as well as a shifting to the younger age within the last five years. Surprisingly, most common were secondary tumours in case of larynx carcinomatas. Patients suffering from secondary tumours show a bad prognosis, however, their maximum survival does not differ considerably from that of patients suffering from recidivations, resp. metastases. Because of the early diagnosis of the secondary carcinomatas the prognosis will depend on the primary carcinoma in most of the cases. The prognosis data indicate that independently from the fact whether there is a primary or a subsequent tumour, the therapy to be applied can only be a combined therapy consisting of operation and ray-therapy. The present examinations confirm reports with regard to disturbance of the p53 regulation that also play an important role in case of the head-neck area. The parallel analysis of MIB1 as a proliferation marker showed in case of the primary carcinomatas a correlation of positive p53-immunocolour with moderate and strong proliferation. Tumours in the hypopharynx and larynx showed a significantly smaller proliferation than that of the oral cavity and oropharynx. In case of the primary and secondary tumours the proliferation is more common in case of the G3-tumours. CONCLUSIONS: The in total modest differences between the primary and secondary carcinoma with regard to the DNA-ploidy; the proliferation and the p53-expression presumably originate in their formation within the scope of a so-called field canceration. Because of the field canceration supposed for the mucous membranes of the upper aerodigestive tract, the check-ups of these patients performed in regular intervals must not be limited in any case to the area of the primary tumour. They will have to consider the entire visible area of the upper respiratory and esophageal tract.

Adult↗
PubMed2000

[Lipoma-like liposarcoma of the tongue].

BACKGROUND: Liposarcomas of the tongue are rare. To date only 7 cases have been reported. PATIENT: We report a new case of a well differentiated lipoma-like liposarcoma of the body of the tongue in a 71-year old woman. Complete uneventful resection was performed. Histologically the tumor consisted of fat cells with occasional lipoblasts and spindle cell areas. There is no sign of recurrence of the tumor 2 years later. RESULTS AND CONCLUSIONS: Liposarcomas of the tongue are rare neoplasms. All cases reported were histologically well differentiated. Liposarcomas have to be considered in the differential diagnosis of solid masses of the tongue.

Aged↗
PubMed1999

[Anterior hyperostosis of the cervical spine: diagnostic studies and surgical therapy].

BACKGROUND: Dysphagia due external compression by anterior hyperostosis of the cervical spine is rare. The diagnosis may be established by conventional X-ray of the spine, esophagogram, and CT. PATIENTS: We operated on three patients with large anterior osteophytes from C3 to C7. In two cases morphologic changes of the cervical spine were the main cause of dysphagia. One patient with progressive hypopharynx cancer had hyperostosis of cervical spine as secondary findings. RESULTS: The patients were asymptomatic, post-operatively. CONCLUSIONS: Cervical osteophytes can be detected in 20-30% of the population in asymptomatic patients. The therapeutic approach depends on the extent of dysphagic complaints. Painful dysphagia is a indication for surgery. The anterolateral extrapharyngeal approach is commonly preferred with anterior hyperostosis between C4 and C7. The transoral intrapharyngeal approach has been used in patients with hyperostosis of cervical vertebra C2/C3. Interdisciplinary orthopedic and ENT surgical treatment is without complications and yields good functional results.

Cervical Vertebrae↗
PubMed1998

Absence of an association between IgE-mediated atopic responsiveness and ADHD symptomatology.

There are mixed research results in the literature regarding a possible association between Attention Deficit Hyperactivity Disorder (ADHD) and atopic disorders. If such an association were supported, the implications for underlying pathophysiology would be significant. We evaluated level of atopic responsiveness (based on IgE-mediated response to skin prick tests) in 312 referrals to a pediatric allergist. Based on the atopy code, children were categorized as non-atopic, or moderately or severely atopic. Parents completed the Child Behavior Checklist (CBCL). Univariate analyses on the eight CBCL subscales revealed no differences between the atopic groups. Our results do not support an association between IgE-Mediated atopic responsiveness and ADHD, but they do not rule out an association between allergic symptoms and ADHD based on some other mechanism.

Adolescent↗
PubMed1995

[Surgical therapy of oropharyngeal carcinoma within the scope of interdisciplinary tumor surgery].

BACKGROUND: The results of the surgical therapy of patients with extensive squamous cell carcinoma of the oropharynx and their lymph node metastasis, postoperative follow-up, and rehabilitation depend on the collaboration between ear, nose, and throat surgeons and maxillofacial surgeons. Modern reconstruction techniques permit single-session surgical treatment with a reduced period of hospitalization. The most important therapeutic aim is to improve patient well-being. PATIENTS: Over a period of two years, 45 patients underwent the same surgical procedure. These patients were all in stages III or IV of their disease. RESULTS: This procedure consists of a temporary lateral osteotomy of the mandible with or without resection of the mandible, to provide broad exposure of the tumor of the oropharynx. Apart from the broad exposure, the advantage of this surgical method lies in simple reconstruction using a pedicled and microanastomosed flap. Internal fixation with six and four-hole titanium plates is a reliable method for restoring the stability of the mandible. In six patients, complications occurred in connection with the plate fixation. In four patients, we observed osteomyelitis of the fragment fissure or sequestration. Plate fracture and pseudarthrosis occurred in one patient each. CONCLUSIONS: In our clinical experience, the microvascular anastomosed radial flap proved to be the ideal free soft tissue transplant. One of its primary advantages is its plasticity and hence good post-therapeutic functional results. The jejunal flap has become less significant them the radial flap; the advantage of mucous membrane transfer is lost after radiation and a corresponding postoperative interval. In patients with large, voluminous defects, the use of myocutaneous flaps, especially from the latissimus dorsi, is still justified.

Adult↗
PubMed1995

Extra-abdominal aggressive fibromatosis after treatment of a Morbus Hodgkin. A case report.

The proliferations of the connective tissue, which are summed up under the term fibromatoses, assume a special position with regard to their biologic behavior. While superficial fibromatoses are more likely to grow slowly, musculoaponeurotic fibromatoses (Desmoid tumor)--like malignant tumors--show a locally bound aggressive, rapid growth behavior. A metastazation, however, can never be proved. The research on etiology of fibromatoses has yielded only little knowledge. Besides genetic and hormonal factors, physical reasons are under discussion, too. The present study aims to add another description of a case report to the small number of case presentations on radiotherapy-associated fibromatosis. In 1977, a now 67-old-patient was irradiated because of a Morbus Hodgkin lymphoma in the left side of his neck. Prior to the radiation, the patient had undergone several surgeries. 17 years after the radiation, the patient developed an aggressive fibromatosis (prelaryngeal, right) in the formerly irradiated region. As the localization of the fibromatosis does not allow us to establish a connection to his numerous operations preceding the fibromatosis, a radiation-associated Desmoid tumor must be assumed. Immunohistologically, no estrogen receptors were detectable.

Actins↗
PubMed1994

[Clinical and catamnestic studies after oto- and rhinobasal skull fractures].

The large number of craniocerebral injuries with fractured bones entails an essential field of diagnostic and therapeutic activities for the hospital-based otorhinolaryngologist. It is only with the active involvement of experienced clinicians that paranasal sinuses can be inspected, lesions of the dura mater closed and functional structures of the petrous bone restored. Over a twelve-year period, 311 injuries of the base of the skull were treated in the Magdeburg Department of Otorhinolaryngology. Clinical findings, complications and therapeutic methods used during acute treatment, as well as permanent and late effects in patients with anterior and posterior skull base fractures were analyzed in a comparative approach. Despite early surgery of frontal base fractures, late sequelae have been extensive and resulted in far-reaching changes in patients injured. Temporal bone fractures have presented less problems following mainly conservative acute treatment, with late sequelae exclusively comprising local symptoms in the area of the fracture. Analysis of the present results of treatment demonstrates that otorhinolaryngologists, in cooperation with neurosurgeons, traumatologists, oral surgeons, ophthalmologists, neurologists and intensive care physicians, can efficiently and adequately treat fractures of the base of the skull.

Adolescent↗
PubMed1994

Lack of adverse reactions to measles, mumps, and rubella vaccine in egg-allergic children.

BACKGROUND: Controversy exists regarding allergic reactions to measles, mumps, and rubella (MMR) vaccine in egg-allergic patients. To date there have been only isolated reports describing egg-allergic patients with anaphylaxis to MMR vaccine. OBJECTIVE: Our study was designed to monitor possible adverse reactions in egg-allergic children receiving MMR vaccine. METHODS: Initially prick and intradermal testing with MMR vaccine was carried out. The first 120 children were screened in this fashion, with frequent irritant reactions occurring with skin testing but no subsequent reactions when full-strength vaccine was administered. The subsequent 380 children received the undiluted MMR vaccine without prior skin testing. DESIGN: Over an 8-year period, MMR vaccine was given to 500 egg-allergic children in outpatient setting. RESULTS: No anaphylactic reactions were observed in any of the 500 children immunized with MMR vaccine. Five children showed minor rashes within two hours of administration of the MMR vaccine. CONCLUSIONS: It is therefore felt the previously reported adverse reactions to MMR vaccine represent reactions to other vaccine components rather than the suspected egg antigens. The presence of egg allergy should therefore not be considered a contraindication to MMR immunization.

Child↗
PubMed1990

Adrenal cortical function after long-term beclomethasone aerosol therapy in early childhood.

Ten asthmatic children were studied by tetracosactrin stimulation tests after receiving beclomethasone dipropionate aerosol (BDA) for periods of up to 12 months. Clinical improvement occurred in all children while receiving BDA. No change in adrenal function could be demonstrated by comparing the tetracosactrin stimulation tests before and after treatment with BDA.

Adrenal Cortex↗
PubMed1985

Cough syncope mimicking epilepsy in asthmatic children.

Cough syncope is a more common complication of childhood asthma than formerly recognized. We report twelve children with typical cough syncope who were identified in a pediatric clinic over a period spanning seven years. The condition may be confused with epilepsy because of frequently associated brief clonic convulsive movements during the height of the cerebral anoxia. Cough syncope is readily distinguished from epilepsy by a thorough history. The management and prevention of cough syncope is directed at the aggressive control of bronchospasm in children with asthma.

Adolescent↗