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Biomedical subjects

A Stefanou

Publications and source records attributed to A Stefanou.

6 recordsLinked to original sources
PubMed1999

3D spiral CT imaging of bone anomalies in a case of diastematomyelia.

The case of a 48-year-old woman, suffering from a diastematomyelia, is presented. This case and the diagnostic findings are used to demonstrate the demands on imaging methods with respect to a new classification of split cord malformations (SCMs) recently published. Although MRI is the method of choice for imaging of the spinal cord generally, only X-ray methods and especially conventional computer tomography provide the information necessary for correct classification of SCMs. Additional 3D-reconstructions from suitable CT-data are helpful in visualizing complex anomalies of bony structures found in most cases of SCM.

Female↗
PubMed1998

Image quality of spiral CT versus conventional CT in routine brain imaging.

OBJECTIVE: Aim of the study was to compare image quality of spiral (helical) versus conventional (sequential) routine brain scans obtained on a spiral CT scanner of the latest generation. MATERIALS AND METHODS: In a prospective study 60 patients scheduled for cranial CT were examined in spiral (27 cases) or conventional technique (33 cases) after randomization. Two blinded observers rated artifacts, gray--white-matter contrast and overall image quality. RESULTS: No significant differences in artifacts were detected. Concerning gray--white-matter contrast and overall image quality, none or small differences in favour of conventional scans were found depending on the observer. CONCLUSION: On a modern scanner image quality of spiral brain scans in adults is nowadays comparable to or only slightly less than that of conventional scans. On such a machine, spiral mode can be recommended if, for example, rapid scanning or high-quality secondary reconstructions are needed.

Artifacts↗
PubMed1998

Comparing motion- and imagery-related activation in the human cerebellum: a functional MRI study.

Cerebellar activation during execution and imagination of a finger movement was compared. Functional magnetic resonance imaging was used to detect cerebellar activation during execution and imagination of an untrained self-paced finger-to-thumb movement (left and right hand separately). The four fingers were opposed to the thumb in changing sequences freely chosen by the subjects. The activation maps of 10 right-handed healthy subjects were averaged after transformation into a common coordinate space. Averaged activation maps revealed strong motion-related bilateral activation in the anterior lobe of the cerebellum and in the paravermal regions of the posterior lobe. Ipsilateral activity predominated significantly. Compared to motion, imagination of the same task produced lower signal changes, and foci were more variable in position and strength. The averaged activation maps showed activity in the same regions as in motion. Activation in the posterior cerebellar lobe was more prominent extending into the lateral hemispheres. Ipsilateral dominance was significant for right-hand imagery. The left-hand task only showed marginally stronger ipsilateral activation. The activation pattern observed during execution of the finger-to-thumb movement is in agreement with theories of functional cerebellar topography. For imagery, activation at a comparable location may reflect common functionality, e.g., motor preparation and/or timing. Additional activation in the lateral hemispheres may be related to an imagery-specific function.

Adult↗
PubMed1993

[Correlation of serum prolactin and cortisol values with paroxysmal disorders of epileptic and non-epileptic origin and their clinical value].

In 95 patients (44 women and 51 men, aged 14 to 86 yrs., average 44.9 yrs.) the serum levels of prolactin, cortisol and uric acid were investigated 30, 60 and 120 min after seizure-like events. There were 53 fits of epileptic aetiology (EE), mainly tonic-clonic, and 42 attacks of non-epileptic aetiology (NEE). The uric acid of the epileptic patients 30 min postictally revealed significantly higher ratings (p < 0.05) compared to the control group (n = 36), but not compared to the NEE group. Serum cortisol was significantly higher after all investigated disturbances without differences in the EE and NEE group. After epileptic and non-epileptic attacks prolactin was significantly (p < 0.05) elevated in comparison to the baseline. The increase of 3 times the amount of the individual baseline and at the same time exceeding the range of reference were found in 73% of the epileptic and only in 7% of the non-epileptic patients. As hypothesis to the postictal prolactin rise we discuss disturbances in the neurotransmitter equilibrium within the hypothalamic-hypophyseal axis. We regard prolactin as a biochemical marker, which is a valuable aid in the differential diagnosis of epileptic and non-epileptic fits.

Adolescent↗