Gross-total surgery of supratentorial low-grade gliomas under intraoperative MR guidance.

Background And Purpose: Length of survival of patients with low-grade glioma correlates with the extent of tumor resection. These tumors, however, are difficult to distinguish intraoperatively from normal brain tissue, often leading to incomplete resection. Our goal was to evaluate the effectiveness of intraoperative MR guidance in achieving gross-total resection.

Preliminary experience with interactive guided brain biopsies using a vertically opened 0.5-T MR system.

The purpose of our study was to evaluate the feasibility and accuracy of brain biopsies performed within a vertically opened MR system. We worked with the interventional 0.5-T MR "SIGNA SP" (General Electric Medical Systems, Milwaukee, Wis.

[New method of MR-guided mammary biopsy].

Purpose: With a recently installed new open MR tomograph (Signa SP, General Electric MS) it is possible for the first time to examine patients with obscure lesions of the mamma by MR imaging in a sitting position, similar to mammography.

Method: The newly developed positioning device with integrated surface coil permits in combination with the vertical gap in the new magnet and imaging of the mamma with a "real time" sequence a biopsy procedure within a short time and in a manner that is acceptable for the patient. By means of an integrated interactive scan plane guiding system ("flash point tracking system") and special MR-compatible needles and wires tissue samples can be taken, or marking by a wire can be carried out within a short time.

[Operation of multidisciplinary, interventional 0.5 Tesla magnetic resonance tomograph. Technical and logistic problems and initial clinical results].

Multidisciplinary usage of a MRI system with a superconducting 0.5-T magnet (Signa SP, General Electric) with a vertical gap suited for diagnostic and therapeutic interventions raises complex problems. The MR equipment, including a special localizing system and the instruments for diagnostic and therapeutic interventions, is described.

[In vitro investigations for detection of vascular stenosis using spiral CT angiography].

Purpose: This experimental study investigates the suitability of spiral CT angiography for detection of stenoses.

Material And Methods: Three vessel phantoms of 4, 7, and 10 mm diameter were scanned with spiral CT several times using different scanning parameters each time. Axial scans were viewed in different ways.

An examination of the dental state of an Egyptian mummy by means of computer tomography: a contribution to 'dentistry in Ancient Egypt'.

In 1991 mummies from Leipzig collections were investigated by means of conventional X-ray techniques and by computer tomography. The dental state of one of these mummies prompted a re-examination of the question of whether a dental profession actually existed in Ancient Egypt or not. To answer this question, different types of source material are discussed.

[First experiences with electron beam computed tomography of the heart:comparison with heart catheterization and echocardiographic findings].

Aim: To evaluate the diagnostic value of ultrafast CT in comparison to established methods in cardiology.

Material And Methods: Cine and flow studies were performed in 30 patients with cardiac diseases on evolution CT. Cardiac structure and function were analysed visually and quantitatively (left ventricular ejection fraction, left ventricular myocardial mass, patency of coronary arteries, perfusion of left ventricular myocardium).

[Detection of coronary calcification by ultrafast CT compared with coronary angiography].

The angiographical findings of 24 patients with coronary artery disease were compared with qualitative and quantitative detection of coronary calcification by ultrafast CT. Doubts concerning the capabilities of the ultrafast CT for a screening of coronary artery disease arise when the results of one third false positive and false negative findings are considered. Variations in the quantification of coronary calcification were too great to allow a realistic assessment of the degree of stenosis of the coronary arteries.

[Quality control in computed tomography].

In comparison to the constancy checks in conventional roentgenography, quality control in computed tomography (CT) should be limited to a few simple but essential checks for image quality and radiation burden. These requirements, however, can only be fulfilled in part, because of the complexity of CT systems. Possible parameters are: water and air values, pixel noise/contrast resolution, spatial resolution, artifacts, homogeneity, contrast scale/tube voltage, slice thickness, positioning accuracy, image quality of the topogram, radiation dose and film imaging.

[The diagnostic value of CT in siderophilia (primary idiopathic hemochromatosis)].

CT, due to its high resolution of density, is suitable, within certain limits, to quantify iron contents in the liver. - Diagnostic value and limits of dual-energy-computed tomography after 38 examinations, 31 of them in patients with verified haemochromatosis, are described: In a progressive state of iron overload a high correlation exists between results of computed tomography and usual reference methods of iron metabolism (iron determination by absorption spectrometry and histologic examination, serum-iron-level, serum-ferritin-level, relative transferrin saturation, desferal test). - With a specificity of nearly 100% CT shows a minor or medium iron overload only with low sensitivity.

[Computer tomographic evaluation of left ventricular kinetics].

The judgment of the function of the left ventricle is computer-tomographically possible using the ECG-regulated cardio-computer-tomography in a temporary resolution of about 0.1 sec. The qualitative and quantitative evaluation of the systolic and diastolic changes of the ventricle in patients with normal CT-findings, with idiopathic hypertrophic subaortic stenosis and with disturbances of motility in chronic ischaemic heart disease confirms the possible functional evidence known from literature.