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Biomedical subjects

L Prayer

Publications and source records attributed to L Prayer.

30 records · Page 2Linked to original sources
PubMed1990

Cranial MRI in Wilson's disease.

Thirty-eight patients with biochemically proven Wilson's disease underwent magnetic resonance-imaging (MRI) of the brain as well as neurological examinations. The patients were scanned using spin-echo (SE) sequences; the neurologist was looking for typical symptoms: dysarthria, tremor, ataxia, rigidity/bradykinesia and chorea/dystonia. Pathological MR findings believed secondary to this uncommon inherited disorder of copper metabolism were found in twenty-two subjects. Focal abnormalities were seen in the lenticular, thalamic and caudate nuclei as well as in brain stem and white matter; these lesions were best demonstrated on T2-weighted sequences as hyperintense areas. In eight patients we found diffuse brain atrophy with consecutive widening of the ventricular system. Five subjects showed mild, nineteen severe neurologic deficits. Generally there was no correlation between MR findings and clinical neurological symptoms; the impairment of cell-metabolism causing functional alterations of the brain precedes morphological changes. During treatment with the copper chelator D-penicillamine there seemed to be a phased course of disease. Shortening of T1-relaxation due to paramagnetic influence of copper was not seen; a possible explanation could be intracellular deposition--a proton-electron-dipolar-dipolar-interaction would therefore be impossible.

Adult↗
PubMed1990

Sonography versus palpation in the detection of regional lymph-node metastases in patients with malignant melanoma.

High-resolution real-time sonography was done in 217 patients with malignant melanoma to compare its value in detecting regional lymph-node metastases with that of palpation. Lymph-node metastases were found in 29 patients by ultrasound whereas, by palpation, metastases were detected in 15 patients only. The presence of metastases was proven by histopathology after surgical lymphadenectomy in these ultrasound positive cases. Thus sonography was superior to palpation, and in addition permitted distinction between metastatic changes and inflammatory lymph-node enlargement. Ultrasound is recommended for preoperative staging as well as in postoperative monitoring of patients with malignant melanoma.

Adult↗
PubMed1990

Diagnostic imaging of tumor invasion of the mandible.

Several imaging techniques, such as conventional radiography, sonography, computed tomography, isotope scanning and magnetic resonance tomography are used for evaluation of malignant tumors in the region of the floor of the mouth and the tongue. At present, conventional radiography, as well as computed tomography and isotope scanning are the techniques preferred for examination of the mandible. In this study, the results of conventional radiographic examination, computed tomography, ultrasound and Tc scanning in detecting tumor invasion of the mandibular bone, are documented and correlated to surgical and histological findings. The results suggest that ultrasound--our primary diagnostic imaging technique for evaluation of tumors of the floor of the mouth and the tongue--not only provides excellent imaging of tumor extension in soft tissue but also allows accurate diagnosis of osteodestructions of the mandible. In most regions ultrasound had the same accuracy in detecting tumor invasion of the mandible. In the alveolar process, however, sonography was superior to other imaging techniques. The lingual surface of the mandibular ramus can not be screened by the extraoral sonography.

Carcinoma, Squamous Cell↗
PubMed1990

[Linear versus circular polarization of head coils: comparison on phantoms and in the clinic].

Two different head coils--one with linear polarization and the other with circular polarization--were compared under the same measurement conditions. Comparison was done on a phantom with water-filled and gadolinium-filled pin-holes, as well as on anatomical MR images of 23 volunteers. In three volunteers the whole brain was examined while, in the remaining 20 volunteers the sella region or cerebellopontine angle region was examined. Criteria for comparison were signal-to-noise ratio, background noise, and detail resolution (phantom), as well as subjective criteria--image sharpness, anatomical, contrast, and recognition of anatomical details--, evaluated on anatomical MR images by four radiologists independently of each other. The results show a significant improvement of signal-to-noise ratio, lower background noise and therefore marked improvement of images sharpness, and moderate improvement in the recognition of anatomical details using the circular polarized head coil; as for as detail resolution and anatomical contrast were concerned, however, no significant difference was seen between the two coils. Major advantages of the circular, polarized head coil in clinical application are shorter measurement times (reduced number of acquisitions), as well as thinner slices without loss of signal-to-noise ratio.

Brain↗
PubMed1990

[CT and MRT in mediastinal and hilar space-occupying lesions].

Thirty-eight patients with mediastinal and/or hilar masses were imaged by computed tomography (CT) and magnetic resonance imaging (MRI). Results were analyzed retrospectively regarding the ability to demonstrate the masses, their number, size, definition, location and tissue characteristics. CT and MRI showed equivalent results in 32 cases; additional information was obtained in two patients by CT, in four patients by MRI. In view of the specific advantages and limitations of both CT and MRI we believed that in patients with mediastinal and/or hilar masses, contrast enhanced CT remains the procedure of choice after performing plain chest radiographs; in certain cases MRI will prove useful for further evaluation.

Adolescent↗
PubMed1989

[Sonographic detection of osteodestruction of the mandible].

32 patients with osseous destruction of the mandible were examined sonographically. The results were compared with those of plain radiographs. In 30 patients, discontinuation of the cortex was clearly evident. Sonography could detect osteolytic lesions in the corpus region, in the angle and on the buccal side of the rami of the mandible. 2 cases of osteodestruction on the lingual side could not be seen.

Aged↗
PubMed1989

[Primary lymph node metastases in malignant melanoma studied via high-resolution real-time sonography--its value and indications].

To detect regional lymph node metastases 217 patients with melanoma were examined both sonographically and clinically. Metastases were found in 15 patients by means of palpation, and in 26 patients via ultrasound. Sonography was evidently superior and enabled differentiation between metastatic changes and inflammatory enlargements of lymph nodes. Because of its excellent accuracy ultrasound examination should be performed both in preoperative tumour staging and in posttherapeutic monitoring.

Adult↗
PubMed1989

[Lung changes in amiodarone therapy].

We describe a 59-year-old patient who was treated with amiodarone for severe ventricular arrhythmia. After a two-year period of medication the therapy had to be abandoned because of pulmonary changes on the chest X-ray that mimicked lung oedema; no other cause for the pulmonary opacities than an adverse effect of amiodarone was to be found. The radiological changes in the lungs regressed within one year with no specific therapy being administered.

Amiodarone↗
PubMed1989

[Gadolinium-DTPA in magnetic resonance tomography. Clinical use--indications].

Magnetic resonance tomography was performed on 158 patients with different indications before and after the administration of contrast medium. The MR examination included various plain T1 and T2 weighted spin echo sequences as well as T1 weighted examinations after intravenous application of Gadolinium-DTPA ("Magnevist", Schering AG) in a dosage of 0.1 mmol/kg body weight. The following conclusions were drawn: The sensitivity of MR in detecting brain tumors, acoustic neuromas and pituitary adenomas was improved considerably after the administration of "Magnevist". To diagnose the type of tumor, the criteria which apply to Gd-DTPA are similar to those used for iodine-containing contrast medium in CT. In about 2/3rds of the cases, delineation of pathological tissues from surrounding edema and normal structures was better than in plain films. Hence, accurate, pretherapeutic staging of bronchial carcinomas and an exact definition of the expansion of the malignancies in the muscle-skeleton system were possible. In respect of tumors in the region of the base of the skull, we could omit T2-weighted sequences without noticeable loss of diagnostically relevant information; the examination time could thus be shortened by about 12 minutes.

Adolescent↗
PubMedDate not supplied

MR contrast arthrography (MRA) in osteochondrosis dissecans.

Osteochondrosis dissecans (OCD) is a lesion that characteristically affects the articular cartilage and subchondral bone with the potential of fragmentation and separation. Exact assessment of cartilaginous and subchondral bony changes is mandatory for the planning of adequate treatment. Therefore, we examined 25 knees using spin echo (SE) and gradient echo (GE) sequences on a 1.5 T superconducting unit prior to and following intraarticular administration of 40 ml of a 2 mmol/L Gd-DTPA solution (MR arthrography). For evaluation (staging) a modified Clanton and DeLee scheme was employed. Verification by arthroscopy or arthrotomy was available in 24 cases. A correct diagnosis of OCD with regard to its type prior to intraarticular injection of Gd-DTPA was possible in 39.3% using T1-weighted SE sequences and in 57.4% on GE sequences. After intraarticular administration of Gd-DTPA, the rate of correct diagnoses improved to 92.9% on T1-weighted SE sequences and 100% on GE sequences. Magnetic resonance arthrography appears to be helpful for the exact assessment of the articular cartilage overlying OCD lesions as well as for the differentiation between partial and complete separation of cartilaginous or osteocartilaginous fragmentations.

Adolescent↗
PubMedDate not supplied

CT and MR accuracy in the detection of tumor recurrence in patients treated for ovarian cancer.

OBJECTIVE: The aim of this prospective study was to evaluate the accuracy of clinical examinations (palpation/determination of serum tumor-associated antigen CA125 level), CT, and MRI in the detection of tumor recurrence in patients with treated ovarian cancer. MATERIALS AND METHODS: Twenty-four patients who had been treated for ovarian carcinoma were prospectively examined by clinical means (palpation/serum tumor-associated antigen CA125 level), CT, and MRI to assess their accuracy in detecting recurrent disease; results were correlated with surgical/bioptic/pathoanatomic findings. Nine patients had relapse; 15 women were disease-free. RESULTS: Examinations were true-negative in 14 patients (on palpation/CA125, CT, and MRI) and true-positive in 9 on palpation/CA125, in 6 on CT, and in 7 patients on MRI. False-positive examinations occurred in one patient on palpation/CA125, CT, and MRI and false-negative in zero on palpation/CA125, in three on CT, and in two on MRI, a sensitivity of 100% for palpation/CA125, 66.6% for CT, and 77.7% for MRI and a specificity of 93.3% for palpation/CA125, CT, and MRI. Accuracy of palpation/CA125 examinations was 95.8% in comparison with 83.3% for CT and 87.5% for MRI. CONCLUSION: Our results suggest that in the follow-up of ovarian cancer patients, assessment of serum tumor-associated antigen CA125 level is accurate in the determination of patients with tumor recurrence. Computed tomography is the primary imaging modality to prove macroscopic disease recurrence and can spare these patients from invasive restaging second-look laparotomy; MRI should be performed in women with questionable macroscopic recurrent tumor and negative CT examination. Neither CT nor MRI can confidently exclude microscopic disease.

Antigens, Tumor-Associated, Carbohydrate↗