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Biomedical subjects

U Bick

Publications and source records attributed to U Bick.

53 records · Page 3Linked to original sources
PubMed1993

White matter abnormalities in patients with treated hyperphenylalaninaemia: magnetic resonance relaxometry and proton spectroscopy findings.

In order to further clarify the pathogenesis and clinical significance of MRI white matter abnormalities in treated hyperphenylalaninaemia (HPA), ten patients (seven type I HPA, two type II and one type III) underwent T2 relaxometry (n = 8) and/or 1H spectroscopy (n = 7) in addition to conventional MR spin-echo imaging at 1.5 T. Two patients with severe MRI abnormalities had repeat examinations during and after a 6- to 8-month period of strict diet control. The clinical evaluation included a detailed neurological examination. In nine out of ten patients visual evoked potentials (VEP) were obtained parallel to the MR examination. MR imaging demonstrated typical symmetrical areas of prolonged T2 relaxation time predominantly in the posterior periventricular white matter in all but one of type I and II patients. There was no consistent relationship between MRI findings and time of diagnosis/initiation of therapy, IQ or visual evoked potential changes. MRI abnormalities tended to be more severe in patients with poor dietary control and high current plasma phenylalanine levels, whereas a normal MRI was found only in patients with plasma phenylalanine levels continuously below 0.36 mmol/l. There was marked regression of MRI abnormalities already after 3 months of strict diet control. T2 relaxometry showed a bi-exponential behaviour of T2 in the affected white matter, with a slow component of about 200-450 ms, indicating an increase in free (extracellular) water. 1H spectroscopy revealed no signs of severe neuronal damage. We conclude, that the observed white matter changes in treated HPA probably represent reversible structural myelin changes rather than permanent demyelination.

Adolescent↗
PubMed1992

Therapeutic use of surfactant in neonatal respiratory distress syndrome. Correlation between pulmonary X-ray changes and clinical data.

As part of a multicenter surfactant rescue study, the chest X-rays of 239 preterm and term infants were analyzed. To study the influence of surfactant administration on radiographic appearance, 130 patients with a clinical and radiological diagnosis of typical respiratory distress syndrome were selected, in whom adequate chest x-rays before and within 48 h after treatment were available. Median gestational age was 30 weeks (range 25-38 weeks), median birth weight was 1335 g (range 625-3450). The time of surfactant application ranged between 90 min and 24 h after birth (median 6 h). The most common finding after surfactant administration was uniform (n = 47) or disproportionate (n = 46) improvement of pulmonary aeration, which showed a significant correlation to posttreatment reduction of oxygen requirement (p less than 0.0001). Asymmetric clearance was more often localized on the right side and usually disappeared within two to five days. Only in 13 patients no change of ventilation was found. Development of interstitial emphysema (n = 24, including three patients with pneumothorax) after surfactant treatment was an unfavourable prognostic sign. 54% of these patients (13 of 24) died within the first month of life, compared to 8% (7 of 93) in the group of patients with initial improvement of ventilation.

Female↗
PubMed1992

Ovarian cysts in the fetus and neonate--changes in sonographic pattern in the follow-up and their management.

In a multicenter trial we retrospectively evaluated the clinical and sonographic data of 49 neonatal ovarian cysts, 44 of which were detected prenatally and 5 on the first day after delivery. Of the 44 prenatally detected cysts 39 were purely cystic, 5 echogenic or had a mixed pattern. In 20 patients the cystic appearance changed during delivery from purely cystic to a mixed pattern being independent on the size of the cyst. 26 of the 44 cysts were treated surgically. Salpingotorsion was found in 8 and was independent on the size of the cyst. In 15 a salpingo-oophorectomy or oophorectomy was performed, in 11 the ovary was saved. 23 patients were followed sonographically: 15 cysts showed complete resolution within 14 months without correlation to the sonographic pattern. The volume of these cysts varied between 5 and 71 ml. Neonatal ovarian cysts disappear spontaneously frequently and rarely cause severe symptoms. The authors recommend follow-up by ultrasound as the primary modality. Surgical intervention is recommended only if the cyst is space-occupying and percutaneous puncture can not be performed or in the case of emergency.

Female↗
PubMed1992

Neurological outcome in 22 treated adolescents with hyperphenylalaninemia. A clinical and electrophysiological study.

We examined clinically and electrophysiologically 22 adolescents suffering from hyperphenylalaninemia. Three of 16 treated patients showed slight impairment of proprioception; their examination was otherwise unremarkable. Subclinical deficits were present in the central motor and sensory pathway. In addition, we had evidence of a minor sensory neuropathy: 32% of the 22 patients had subclinical deficits in the visual system. However, in contrast to earlier reports we saw no relation to the degree of metabolic control. Our results suggest that treated adolescent patients with hyperphenylalaninemia show neurological dysfunction that may be related to morphological, as well as pharmacological changes.

Adolescent↗
PubMed1992

The distinction between benign and malignant liver tumors on sonography: value of a hypoechoic halo.

OBJECTIVE: The purpose of this study was to determine the diagnostic value of the sonographic halo sign (defined as any hypoechoic rim in the periphery of a lesion) in distinguishing between benign and malignant isoechoic and hyperechoic liver lesions on sonography. MATERIALS AND METHODS: Sonograms of the liver in 50 patients with proved benign liver tumors and in 50 patients with proved malignant liver tumors (seven primary liver neoplasms, 43 metastases) selected during a 13-month period were retrospectively analyzed by four radiologists who had no knowledge of the patients' clinical findings or the final diagnoses. Only a single sonogram was studied in each case. The presence or absence of a hypoechoic halo on the sonogram was the only criterion for distinguishing malignant from benign hepatic lesions. RESULTS: For 95 of 100 hepatic lesions, the four radiologists were almost (three vs one) or completely (four vs zero) in agreement about the presence or absence of a hypoechoic halo. In the five cases where there were conflicting decisions (two vs two), a final decision (four vs zero) was achieved by reviewing the entire series of sonographic images. A halo could be detected in 44 malignant tumors (88%) and in only seven benign tumors (14%) (sensitivity, 88%; specificity, 86%; positive and negative predictive values, 86% and 88%, respectively). The sonographic halo sign was particularly helpful in distinguishing hemangiomas (n = 29) from metastases (n = 43) (positive and negative predictive values, 95% and 87%, respectively). CONCLUSION: The results of this study suggest that the halo sign on sonograms is useful to distinguish benign from malignant isoechoic or hyperechoic tumors.

Adult↗
PubMed1991

Disturbed myelination in patients with treated hyperphenylalaninaemia: evaluation with magnetic resonance imaging.

Cranial magnetic resonance imaging (MRI) was performed in nine treated adolescents with hyperphenylalaninaemia (HPA) in order to analyse possible changes in myelination. Three patients suffered from type I HPA, four from type II and two from type III (persistent HPA). Images were obtained with a 1.5 T unit using spin-echo-sequences. In all patients with type I or type II HPA, abnormal findings in the cerebral white matter were demonstrated including band-like and/or confluent patchy areas of high signal intensity predominantly in the peritrigonal region, with anterior and posterior periventricular extension and/or involvement of the subcortical white matter. The extent of MRI changes did not correlate with the initiation, duration or quality of dietary treatment. There was also no consistent relationship between electrophysiological changes and white matter abnormalities on MRI. Our findings suggest a disturbance of myelination in patients with treated HPA. These results correspond well with earlier neuropathological and biochemical studies in untreated patients.

Adolescent↗
PubMed1991

Functional and morphological deficits in late-treated patients with homocystinuria: a clinical, electrophysiologic and MRI study.

Seven late-treated patients between the ages of 10-30 years suffering from homocystinuria were examined clinically and electrophysiologically; four had MRI. The clinical examination showed extrapyramidal features and slight impairment of proprioception. Electrophysiological evaluation revealed normal results in the acoustic and central motor system; a minor, possibly vitamin B6 related, sensory neuropathy was detected by peripheral conduction studies. MR imaging showed small focal areas of gliosis in the white matter, generalized cortical atrophy in two patients, but only one small cortical infarct. No changes in the basal ganglia were detected. These results support the view that neurological signs and symptoms in patients suffering from homocystinuria are related to morphological findings, as well as pharmacological effects.

Adolescent↗
PubMed1991

[Diagnostic imaging of the salivary glands in children and adolescents].

In children and adolescents, imaging of the salivary glands is a valuable supplement to clinical examination in various diseases. The choice of the most appropriate radiological technique depends on patient compliance, the necessity of avoiding radiation exposure as far as possible, and the tentative diagnosis made on the basis of the clinical examination. Ultrasonography (US) is the method of choice for the detection of both acute inflammatory disease and masses in the salivary gland and the adjacent tissue. US can also be implemented as a screening method for calculi, though sialography is superior for this purpose. Sialography is the only technique that allows diagnosis and evaluation of the degree of chronic inflammation. Computed tomography and magnetic resonance imaging are required for more deeply located neoplasms of the parotid region.

Adolescent↗
PubMed1991

[A method of estimating doses in digital luminescent radiography].

Digital storage phosphor radiography can produce images of a constant optical density over a wide range of exposure dose by adjusting reading sensitivity. Since overexposed images are not as readily recognized as with the conventional film-screen technique, a formula was designed, which calculates the radiation dose in the film plane from image sensitivity (S factor), latitude (L factor) and average grey value of the region of interest. To verify the formula, 168 measurements with variation of dose, kVp, L factor, S factor and the readout algorithm were performed using the DIGISCAN storage phosphor system (Siemens). The experiments confirmed the validity of the formula for an S factor of below 5000 (values during routine use 50-400). Correlation between dosimetrically measured radiation dose and the calculated dose was 0.997.

Humans↗
PubMed1990

Ultrasonography of the hip in preterm neonates.

Over the period of one year, the hips of 92 preterm neonates were examined by ultrasound. Using the Graf classification only 7% showed an angle alpha between 50 and 60 degrees, which is characteristic of type IIa hips. In all other cases the angle alpha was above 60 degrees (type I). Sonographically there were no pathological cases (type IIg or worse). A reason for the relatively low number of type IIa hips could be that the short osseous acetabular rim and the broad cartilagenous Y-joint in this age group result in a "false" increase of the angle alpha.

Hip Dislocation, Congenital↗
PubMed1990

[The visualization of metal implants with digital luminescence radiography].

DLR makes it possible to integrate conventional radiography into digital communication and storage methods (PACS) into radiology. The use of DLR has been compared with conventional film methods in the demonstration of hip prostheses. The high contrast differences at the edge of the metal implant leads to artifacts, which could result in erroneous interpretation. Suitable image manipulation makes it possible, however, to eliminate these artifacts almost completely. DLR leads to an improvement in diagnosis in those complications not specifically related to the prostheses.

Evaluation Studies as Topic↗
PubMed1990

[Tuberculous spondylitis following BCG vaccination].

A case of a rare form of BCG osteomyelitis in the spine is presented. After vaccination, the disease started with a lymphadenitis. Later an abscess extended from the pelvic along the psoas muscles into the retroperitoneum. The soft tissue mass extended paraspinally and epidural involvement was also apparent. The vertebral involvement was detected by CT. The radiological findings are discussed with reference to the literature.

BCG Vaccine↗
PubMed1990

[Thoracic sarcoidosis].

Sarcoidosis is essentially a granulomatous disease of unknown etiology. The pathogenesis is assumed to consist in an abnormal immune reaction to a still unidentified antigen. The commonest manifestations of sarcoidosis are mediastinal and hilar lymphadenopathy and pulmonary infiltrates. The complex variety of clinical presentations of sarcoidosis means that the differential diagnosis has to include a wide range of entities. The clinical and radiological features of thoracic sarcoidosis are described, and the spectrum of relevant investigations is discussed. With respect to radiological diagnosis, computed tomography, with its higher sensitivity than other techniques, is of particular value for the precise determination of the morphological correlate of pulmonary and nodal changes and their functional relevance.

Diagnosis, Differential↗
PubMed1990

[Changes in the lungs in mucoviscidosis. Feasibility and advantages of different imaging techniques].

Pulmonary abnormalities in cystic fibrosis result from the obstruction of small bronchi by highly viscous mucus. Chronic obstructive lung disease and recurrent pulmonary infections result in a typical radiographic pattern later in the disease. Most patients can now be expected to survive into adulthood. The radiologist must make a careful comparison of serial films in order to detect complications early. By far the most important imaging modality is the conventional chest radiograph. CT is more sensitive for detection of structural abnormalities of the lung. Bronchography is a dangerous procedure and can lead to rapid deterioration of lung function. Lung scanning is a very sensitive method for demonstrating regional disturbances of ventilation and may reveal abnormalities earlier than conventional radiographs. In severe hemoptysis, selective bronchial arteriography with embolization of the bleeding vessel can be a life-saving procedure.

Angiography↗