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Biomedical subjects

W Dewes

Publications and source records attributed to W Dewes.

At least 19 recordsLinked to original sources

[High resolution small parts sonography (7.5 MHz) of the head and neck region].

Frequently, sonography of the head and neck serves only for assessment of the thyroid and arteriosclerotic lesions of the extracranial vessels. This article gives a review of ultrasound of the remaining cervical structures, particularly spaceoccupying lesions. The differentiation between malignant and benign lymphadenopathy or between intraglandular and extraglandular abnormalities of the salivary glands is possible with an accuracy between 90 and 95 %. Limitations of the method lie in the difficult access to the skull basis as well as the retropharyngeal and retrotracheal space.

Diagnosis, Differential

Cerebral MR in ophthalmoplegia plus.

PURPOSE: To evaluate MR patterns in ophthalmoplegia plus and correlate them with clinical symptoms. METHODS: MR was performed on a 1.5-T whole-body scanner with T2-weighted gradient-echo and spin-echo images. The retrospective analysis included 19 patients with clinically established diagnoses of ophthalmoplegia plus. RESULTS: Two types of cerebral MR abnormalities were found in ophthalmoplegia plus: brain atrophy and hyperintensities restricted to the white matter and basal ganglia, which appeared as either focal or diffuse areas of high signal intensity and were of strictly supratentorial location. No specific distribution was found. These findings differ markedly from infarction-like lesions found in mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes. CONCLUSIONS: MR is sensitive for the detection of central nervous system involvement in ophthalmoplegia plus, but findings are nonspecific. However, cerebral MR in ophthalmoplegia plus is different from other mitochondrial encephalomyopathies and underlines the clinical differentiation of mitochondrial encephalomyopathies.

Adolescent

Trichinosis: a prospective controlled study of patients ten years after acute infection.

The existence of chronic trichinosis as a disease entity is still a matter of debate. For 10 years after an outbreak of infection with Trichinella spiralis, we conducted a prospective controlled study of the patients involved. At the termination of this investigation, we undertook clinical, biochemical, serological, immunologic, neuroradiological, radiological, and psychological studies of 128 originally infected persons and 16 controls. The categories of symptoms most often documented in persons who had been infected were muscular (90%), ocular (59%), neurological (52%), and psychological (52%). Impaired muscle strength (56%), conjunctivitis (55%), and impaired coordination (32%) were the clinical manifestations most frequently encountered. Thirty-eight percent of the 128 originally infected patients still had IgG antibodies to T. spiralis after 10 years. Magnetic resonance imaging of the brain revealed no abnormalities. No calcifications of residual larvae were detected by mammography or muscle biopsy. The level of performance in psychometric tests was lower in the originally infected population than in the general population. Although patients who had had trichinosis differed significantly from controls in terms of a variety of parameters even after 10 years, we found insufficient evidence on which to conclude that chronic trichinosis exists as a distinct entity.

Adult

[The diagnosis of bone marrow lesions in the MR tomogram in children with diseases of the hematopoietic system with special reference to post-therapy changes].

119 MR-examinations of both tibiae, knees and the lower part of both femur were performed in 41 children suffering from bone marrow disease (27 ALL, 4 AML, 3 NHL, 1 agranulocytosis, 6 anaemia). T1- and T2-spin-echo sequences and a T2-gradient-echo sequence were used. Bone marrow changes in leukaemia were diffuse before therapy and patchy after therapy. Due to their different signal in T2-weighted images, differentiation of the post-therapeutic patchy findings into infiltrations, fibrosis, necrosis and siderosis seems to be possible. In future, MRI will be the method of choice for screening and controlling bone marrow disease if the examination time is shortened by using only a T1-spin-echo sequence and a T2-gradient-echo sequence.

Adolescent

[The demonstration and staging of bladder carcinoma. A comparative study between magnetic resonance tomography, computed tomography and radioimmunoscintigraphy].

The purpose of the present study was to compare the effectiveness of MRI, CT and radioimmunoscintigraphy in the staging and detection of bladder cancers in 28 patients. We distinguish two groups: Group I included the tumour stages CIS-T3A and the second group the deep infiltrative tumours T3B-T4. MRI was slightly superior to CT in respect of tumour staging (75% correct results as compared to 63%). No understaging occurred with MRI, whereas in 22% of the cases the stage of the tumour was underestimated using CT diagnostics. Overstaging occurred in 25% of the MRI and 15% of the CT-diagnostics, respectively. RIS cannot distinguish the tumour groups, and hence this method is useful only for the detection of the primary tumour and metastases. In 77% of cases the tumour was detected and in 15% the tumour could be safely excluded.

Adult

[MR tomography of the lower limbs of children with diseases of the hematopoietic system].

In 41 children with disorders of the hematopoetic system 119 MR examinations of both tibiae and knees were performed (T1 and T2 spin-echo sequences and a T2 gradient-echo sequence). Before therapy bone marrow changes in leukemia were diffuse, and patchy during and after therapy. Signals in T2-weighted images were different for infiltrations, fibrosis, necrosis and siderosis. In 3 children suspected of suffering from osteomyelitis, Ewing-sarcoma or coxitis, MR examination was the first to show the correct diagnosis. Therefore in children indications for MR tomography should be handled more generously to win time for therapy. Using only a T1 spin-echo sequence and a T2 gradient-echo sequence screening of more than one region is capable of controlling bone marrow diseases.

Acute Disease

[Tuberous sclerosis: broadening of the diagnosis using MR tomography and computed tomography].

Ten children and a 22-y old women with tuberous sclerosis were studied. All children were epileptic but only 8 had skin lesions (white spots, sebaceous adenoma), 4 had rhabdomyoma of the heart and 4 children had astrocytoma of the retina; only in 4 children was the entire triad of tuberous sclerosis seen. The young woman with a hemorrhage of an angiolipoma of the kidney had no other symptoms of tuberous sclerosis. All patients had pathologic CT and MRT findings; 4 different types of lesion were seen in MRT. In order to elucidate human genetic aspects and to demonstrate the underlying disease all children with epileptic disorders and also all patients without the full triad of symptoms should be examined by MRT.

Adult

[Radioimmunoscintigraphy and magnetic resonance tomography in the diagnosis of urinary bladder cancer].

Magnetic resonance tomography is a method which is sufficiently precise to demonstrate morphological changes for tumor staging of carcinoma of the urinary bladder. The stage of the tumor was correct in 68 resp. 86% of the patients. The RIS shows organ and lymph node metastases and has the capability to differentiating between scar and tumor after transurethral resection. The local spread, especially the infiltration depth of the tumor, is not visible. In 90% of the patients a primary tumor was detected, only in 5 cases a false-negative and in 2 cases a false-positive finding was made.

Adult

[Clinical value of the ultrafast gradient echo sequence "Quickflash"].

It is possible to develop faster sequences with 6 mT/m gradient field strength. However, the short gradient switch times which are advantageous for a better image contrast cannot be achieved. Using longer measurement times the influence of the preparation pulses is less dominant. The image quality of the quickflash is poorer than that of conventional SE and GE sequences. In some cases, especially for outline views and in the evaluation of Gd inflow into pathologic tissue or in restless patients, we use the quickflash in clinical routine.

Brain Diseases

Brain SPECT imaging with Tc-99m HMPAO in ophthalmoplegia plus.

In 14 patients with ophthalmoplegia plus Tc-99m hexamethylpropylene amineoxime (HMPAO) brain SPECT imaging was performed. Three patients showed bilateral parieto-occipital hypoperfusions, and two patients had left parietal defects (one with an additional right temporal lesion). Two patients presented with occipital hypoperfusions and one with a distinct hypoperfusion in the medial part of both frontal lobes. Hypoperfusion of the visual cortex might result from permanently decreased input from the degenerated retina. The hypoperfusion in the visual cortex and in other regions alternatively might reflect direct central nervous system (CNS) involvement due to neuronal degeneration or to impaired vascular function caused by morphologically changed mitochondria in smooth muscle and endothelial cells. The data suggest CNS involvement in ophthalmoplegia plus with abnormalities of cerebral blood flow similar to those found in other mitochondrial encephalomyopathies.

Adult

[Cerebral MRT in x chromosome linked adrenoleukodystrophy].

Adrenoleukodystrophy (ALD) is a rare lipid storage disease, characterized among other symptoms by a progressive demyelinization of white matter. Changes are well demonstrated by MRT: Leukencephalopathy begins symmetrically in the occipital lobes of the cerebrum and involves furthermore the splenium of the corpus callosum, the nucleus dentatus and the descending tracts. As neurologic signs may precede signs of adrenal insufficiency, MRT may be important to suspect the diagnosis of ALD, which generally is diagnosed by biochemical tests.

Adrenoleukodystrophy

[MRT and 99mTc-HM-PAO SPECT of the brain in myasthenia gravis].

Fourteen patients suffering from myasthenia gravis underwent cranial MRI and 99mTc-HM-PAO SPECT examinations. T2-WI revealed solitary white matter and/or basal ganglia lesions in four, multiple lesions in eight patients. The evaluation of the rCBF demonstrated a circumscript decrease of cortical perfusion in one patient whereas eight patients showed multiple cortical areas of hypoperfusion. In the context of an increased incidence of intrathecal immune reaction as well as of a constantly impaired cognitive performance of these patients, imaging findings might be a correlate of a primary cerebral manifestation of myasthenia.

Adult

[Cerebral manifestations of Erdheim-Chester disease].

Cerebral manifestations of Erdheim-Chester disease are variable, giving a picture like that of multiple sclerosis. White matter lesions are located mainly in cerebellum and pons and lipid granulomas in the meninges. An asymptomatic lesion in the choroid plexus, with prolonged uptake of Gd-DTPA is described for the first time.

Bone Diseases

[MR tomography and computer tomography of alcohol-induced brain tissue changes].

Results of MRI in five alcoholics suffering from acute neurologic disorders such as ataxia, ophthalmoplegia and confusion are presented. The detection of focal cerebral lesions of high signal intensity in T2-weighted Spin-Echo- and Gradient-Echo-images in periventricular white matter, thalamus and pons combined with patients history and clinical presentation led to the diagnosis of Wernicke-Encephalopathia and Pontine Myelinolysis. MRI was far more sensitive compared with CT.

Adult

[MR tomography, CT and angiography of vascular malformations of the central nervous system].

The findings on MR tomography in 31 vascular malformations of the central nervous system are described; 26 of these had angiography and 24 were examined by CT. There were 19 A-V angiomas, 7 cavernomas and 5 large aneurysms. MRT provided a correct diagnosis in 29 out of 31 cases, angiography succeeded in 19 out of 26 cases and CT in 20 of 24. MRT was superior to CT and angiography. Nevertheless, it cannot replace arteriography, since this is the only method for demonstrating the vascular supply of angiomas and small aneurysms can be demonstrated only by arteriography.

Angiography

[MR tomography following craniocerebral trauma: comparison with computed tomography, electroencephalography and neurologic status].

56 patients with head and brain trauma and in coma were studied prospectively by means of MRT, CT, EEG and neurological examination. All patients had initial CT and EEG admission. MRT showed that in our patients morphological return to normal was the exception. Patients with head and brain injuries should be examined by MRT during the course of their illness. The use of special sequences, such as gradient-echo sequences for the diagnosis of haemorrhagic contusions, is indicated. CT should be retained for evaluating bone injury and cerebral damage during the acute stage.

Adult