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Biomedical subjects

K Mees

Publications and source records attributed to K Mees.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Incidence of Doppler ultrasound detectable stenoses of cervical arteries in patients with cochlear-vestibular symptoms].

Doppler ultrasound examination is an easy and non-invasive examination technique to image the anatomical and functional situation of cervical vessels. An increasing number of ENT-specialists has been using Doppler sonography in the diagnosis of cochlear and vestibular disorders. We analysed the frequency of pathological Doppler examination results of 150 patients with vertigo, hearing loss and tinnitus. Especially patients with vertigo bear a greater risk for stenosis of the extracranial arteries (28%) compared to an asymptomatical population (1%). Patients with hearing loss and tinnitus showed a different degree of artery disorders (23% of the patients with hearing loss; 18% of the patients with tinnitus). Patients bearing no risk for atherosclerosis showed in 13% (vertigo) and 8% (hearing loss and tinnitus) stenosis of the cervical arteries. Thus we found by Doppler ultrasound examination more stenoses in patients with cochlear or vestibular symptoms than in an asymptomatical population. The early attribution of stenosis to a malfunction of the inner ear helps to avoid invasive examinations of cervical vessels. In addition to this, imminent cerebral ischaemia can be revealed at an early stage.

Aged↗
PubMed1992

[Does the otorhinolaryngologist need Doppler sonography?].

Doppler sonography has not only proved to be a non invasive but also a highly sensitive diagnostic tool for imaging of functional vascular disorders. The otorhinolaryngologist who in future will have to deal with an increasing number of neurootological problems, such as tinnitus, vertigo and hearing loss, should cover the Doppler sonographic examination of the vertebral and carotid artery and its branches. Ultrasound examination of these vessels should be performed in all patients suffering from cochlear or vestibular disorders and bearing risks for arteriostenosis. Early diagnosis does not only point out causative vascular changes but also helps to prevent the patients from invalidising or lethal cerebral events. The combination of (Doppler- and B-mode-sonography Duplex sonography) enables the ENT specialist not only to rule out functional vessel disorders but also to look for morphological vascular changes. Duplex scan imaging is far less risky than angiographic procedures and in many cases it is superior to these invasive techniques too.

Blood Flow Velocity↗
PubMed1989

[Free microvascular tissue transfer. Clinical significance in reconstructive surgery of the head and neck].

Free microvascular anastomosed tissue transfer has improved the reconstruction of soft tissue defects dramatically. For reconstruction of facial and cervical soft tissue defects numerous free flaps are available to the head and neck surgeon, however, most of the reconstructive problems can be solved by using a limited number of reliable and versatile techniques. In microvascular tissue transfer, the scapular flap offers similar advantages as to reliability and versatility as the pectoralis major flap in pedicled tissue transfer. In contrast to the scapular flap the groin flap is more bulky, its skin is soft and may carry pubic hair on its medial aspect. After partial maxillectomy or in facial dysplasia facial contour may be restored satisfactory with a completely or partially de-epithelialized scapular flap. In total hypopharyngeal and cervicoesophageal defects the jejunum transplant provides an ideal tubular replacement. If after resection of an intraoral carcinoma with partial mandibulectomy an osteocutaneous transfer has to be achieved the mandibular defect may be reconstructed with bone from the iliac crest or from the radius while the intra- and extraoral tissue defect may be closed with the adjacent skin flaps. For the closure of large penetrating defects of the cheek the inferior epigastric abdominal wall flap in particular has proved a versatile and reliable flap. This flap offers both, a cutaneous and a peritoneal surface. Latter is used for the replacement of the intraoral lining.

Bone Transplantation↗
PubMed1989

[Hormone receptors in the inner ear].

Vasopressin binding sites could be clearly demonstrated in the cochlea. Membrane staining was mainly limited to the apical and ciliar membranes of the cochlear and vestibular hair cells, and hence to membranes in which adenylate cyclase activity could not be demonstrated. In addition to V2-vasopressin receptors that mediate hormonal signals by adenylate cyclase activation and cAMP release, in V1-vasopressin-receptors extracellular vasopressin signal is mediated by the breakdown of inositol phosphates and the release of inositol-triphosphates and diacylglycerol. Inositol triphosphates were found to be responsible for the intracellular mobilization of calcium. The localization of vasopressin binding sites at the hair cell membranes, therefore, suggests that vasopressin contributes to the breakdown and release of phospholipid messenger molecules and is thus probably involved in cochlear and vestibular signal transduction.

Animals↗
PubMed1989

[Modern radiologic diagnosis of the nasopharynx].

The nasopharynx is one of the most delicate areas of the head and neck for diagnosis and treatment. Biopsies can be taken easily under local anaesthesia; however, since many tumours in this particular region grow in the submucosa, biopsies taken from the superficial tissue layers might not show any signs of malignancy. Thus, diagnostic imaging has become important in evaluating the nasopharyngeal region. Until the early seventies, when computed tomography (CT) was introduced, conventional tomography was commonly used. Since the development of CT and --particularly--the "high-resolution" technique, tumour infiltration of the skull base and parapharyngeal space as well as intracranial extension can be evaluated sufficiently and the different compartments of the soft tissue can be clearly distinguished due to their varying density. Magnetic resonance imaging (MRI)--a new technique introduced a few years ago--yields a much better soft tissue contrast than CT. Contrast enhancement after application of Gd-DTPA provides further information on tumour outlines and architecture. Benign lesions can be distinguished from malignant tumours, as well as recurrent tumours from postoperative fibrosis. MRI can also show large bony defects while minor infiltrations of the skull base are detected by HR-CT. Both MRI and CT are well-established methods in diagnosing diseases of the nasopharynx and its surroundings. For evaluations of the vascular supply prior to operation digital subtraction angiography (DSA) might be necessary in some cases.

Contrast Media↗
PubMed1989

[Infratemporal gout tophus--a rare differential diagnosis in primary parotid gland disease].

Soft-tissue tophi can be observed in up to 50% of patients with primary gout. They are firm deposits of monosodium urate in crystal form, which develop from pinhead-size to egg-size in the subcutaneous tissue. In the field of ear, nose, and throat diseases tophi have been described in such rare locations as the wing of the nose, the tongue, the epiglottis, and the arytenoid and thyroid cartilage. Tophus formation at the temporomandibular joint with extension into the fossa infratemporalis has been mentioned only three times in the world literature. -In the present paper, the authors report on the extraordinary location of an urate tophus in the fossa infratemporalis - in this case, there was even destruction of the middle base of the skull - which had been misinterpreted for years, having been diagnosed as a primary disease of the parotid gland.

Aged↗
PubMed1988

[Magnetic resonance tomographic studies of paragangliomas of the glomus caroticum and glomus jugulare using Gd-DTPA].

The value of magnetic resonance tomography in the diagnosis of paragangliomas in the head and neck has been studied and compared with CT and angiography. Magnetic resonance tomography on its own equals the accuracy of CT, but the use of Gd-DTPA improves diagnostic accuracy. In 19 patients with a glomus jugulare tumour, MR tomography with Gd-DTPA accurately diagnosed all tumours larger than 5 mm. In seven patients with a carotid body tumour, it was possible to arrive at an exact differential diagnosis. Sensitivity was better than that of CT or of sonography. Where there is clinical suspicion of a glomus tumour, magnetic resonance tomography with Gd-DTPA should be the first investigation; if there is a positive finding, angiography should be carried out to demonstrate the circle of Willis.

Carotid Body Tumor↗
PubMed1988

[Diseases of the lymphatic system of the head and neck region. A comparative study of MRI and CT].

The diagnostic possibilities of magnetic resonance imaging compared with computed tomography in lymphomas and pathological enlargement of the lymph nodes in the head and neck region are presented. Whereas plain MRI examinations showed the same diagnostic sensitivity as CT, application of the paramagnetic contrast medium Gd-DTPA in 50 of 87 patients clearly increased diagnostic accuracy. Signal intensities of T1- or T2-weighted images before therapy (operation, chemotherapy, radiotherapy) and after administration of Gd-DTPA were enhanced, compared with posttherapeutic and plain examinations. An increase after therapy in two patients signalled a relapse or residual tumour tissue; a decrease in three cases was evaluated as response to therapy. Other differential diagnostic processes such as lipomas, neurinomas, glomus tumours etc. were differentiated with the help of signal intensity curves after administration of contrast media and the use of a gradient echo sequence TR/TE = 30/12 msec with a flip angle of 30 degrees. Differentiation of tissue based on morphological criteria such as homogeneity of tumour tissue or the delineation against surrounding tissue structures showed in the case of Hodgkin's disease and inflammatory diseases mainly homogeneous elements without ring-shaped structure. Non-Hodgkin lymphomas had a predominantly homogeneous structure. In squamous cell carcinomas MR revealed in two cases a ring-shaped enhancement.

Adult↗
PubMed1988

[Magnetic resonance tomography in tumors of the salivary glands--a diagnostic advantage?].

40 patients with clinically palpable salivary gland masses were included in a prospective study to compare magnetic resonance imaging to computed tomography. MRI has proved superior to CT not only in imaging primary lesions but also in diagnosing local and regional recurrences. In evaluating border structures, signal intensity, T1- and T2-values of space occupying lesions, we can determine the tumour status. Besides, we can define to some extent the internal architecture of the salivary gland or intra-resp. periglandular lymph node masses. Better contrast resolution and more specificity can be obtained by the use of contrast medium gadolinium-DTPA. Even small intraglandular and periglandular masses can be clearly distinguished from the sourrounding structures. At present, magnetic resonance imaging offers the diagnostic potency of both sonography and computed tomography. The advantages of MRI and our present indications in imaging salivary gland masses are discussed.

Adenocarcinoma↗
PubMed1987

[Idiopathic hearing loss--dependent on the weather?].

In recent years it has been shown that atmospherics of different frequencies correlate with the onset of epileptic fits and myocardial infarctions. In the present retrospective study (1984) on more than 500 patients with acute hearing loss residing in the Munich area, a statistically significant correlation to atmospherics was also established.

Audiometry, Pure-Tone↗
PubMed1987

[Determination of T2-times of tumor and muscle tissue by nuclear magnetic resonance tomography and resonance spectroscopy--results of a comparative study].

In 13 patients the T2 values of muscular and various tumor tissues was determined by MR under in-vivo conditions. The tumors were confirmed by surgery. In 5 cases there was a neurinoma of the acoustic nerve, in 3 cases a lateral neck cyst, a granuloma of the larynx and some other pathological processes. Intraoperatively the tissues are biopsied and the T2* time is determined by spectroscopy in vitro. Both the muscular and the tumor tissue show higher mean values or standard deviations in MR measurements than in measurements by spectroscopy. The relations between muscular and tumor tissue (quotients) are comparable in neurinomas of the acoustic nerve (n. vestibulo-cochlearis) and lateral neck cysts, the granuloma of the larynx and lymph nodes of the neck, using both examination methods. Calculations of the correlation coefficients of T2 values and quotients of the muscular and tumor tissue point to tissue-specific connections between in-vivo and in-vitro measurements.

Head and Neck Neoplasms↗