[Feasibility of use and limitations of the 3D-MR study technique. Results of 5 years' clinical experience].
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Brain Diseases↗
Biomedical subjects
N Obletter
Publications and source records attributed to N Obletter.
[Value of MRT for therapy of para-sellar tumors].
When planning treatment of tumours in the sella region it is of the utmost importance to obtain precise information about the localization, spread, and (if possible) the type of alteration. Aside from the classic radiographic methods of native diagnosis, angiography, and CT, MRI has been available for some years now. This is a method whereby images can be gained from the various stages of an energetic reaction in the biological substrate: tomograms are possible for any desired plane--those routinely needed for cerebral diagnosis from the horizontal, coronary, and sagittal planes and, given a further improvement of this technology, from special oblique planes which can be matched to the direction of a probable surgical approach. A number of examples demonstrate the significance of this new method, which is a valuable addition to the procedures used up to now: indeed, in some cases it is superior to them. It has been shown that most of the neighbouring structures which border on or have been pushed aside by the tumour in the sella region (blood vessels, brain, optic chiasma, subarachnoid spaces, and occasionally even bone structures) can be identified better than with the procedures used up to now. MRI has thus proved to be valuable, and occasionally indispensable, for the correct choice when considering the many therapeutic methods available for tumours in the sella region.
Adenoma↗
[Use of the 3D procedure in nuclear magnetic resonance tomography in ENT diagnostics].
The use of 3D-gradient-echo sequences improved the diagnosis of malignant tumors of the skull base, the nasopharynx, the nasal cavities, the paranasal sinuses and the upper parts of the parapharyngeal space with relation to the skull base. Therefore the tumor extent and infiltration may be better appreciated than in conventional 2D-spin-echo or gradient echo sequences. Using this method, the examinations of 22 patients with carcinomas could be compared. Precise tumor delineation was achieved in six of these patients when compared with surgical and histological findings. The 3D sequences most frequently used were FLASH 40 degrees with TR of 40 ms and the shortest TE (5 to 6 ms). 3D turbo-FLASH (MPRage) with Gad-DTPA was applied in order to shorten the acquisition time by half and especially to reduce motion artefacts.
Follow-Up Studies↗
[MRT of orofacial tumors--initial clinical experiences with turbo-flash intensity studies].
We examined 36 patients with carcinomas of the tongue and the floor of the mouth. In 11 cases, a clear definition of the tumor extent was not possible using T2 w. spin echo sequences and T1 w. spin echo and gradient echo sequences after injection of contrast material. This delineation was attained with Turbo-FLASH intensity-vs-time studies (Gad-DTPA). The time of acquisition of each measurement was about 1 sec. At the end of injection of Gad-DTPA, 30 measurements with a delay of 1 sec between two measurements were performed. Using this technique, a marginal zone at the boundary of the tumor of very high signal intensity was visible within first minute after Gadolinium injection. This method is not required in the case of clearly hypointense (majority of the tumors) or hyperintense (minority) lesions on T1 w. Gadolinium-enhanced SE or GE images.
Aged↗
[Thrombocytopenia-induced parenchyma hemorrhage in a newborn infant. A contribution to the etiology of so-called arachnoid cysts].
We report on a newborn baby with thrombocytopenia who developed neonatal seizures caused by a temporal lobe hemorrhage as shown by cerebral ultrasonography. This hemorrhage was followed by a cyst isodense to intracerebral fluid. Differential diagnostic aspects concerning the etiology of arachnoideal cysts will be discussed in relation to the post-hemorrhagic course and the sonographic or the magnetic resonance tomography findings respectively.
Arachnoid Cysts↗
[Significance of reprocessed 3D gradient echo sequences in spinal MRT for surgical interventions in syringomyelia].
Taking a patient with advanced syringomyelia as an example, the article presents a method in which reprocessed 3D-gradient echo sequences from spinal MRI allow centred reconstructions which show all sections of the syrinx, even where the spinal column is curved. This method played an essential role in satisfactorily determining the position of the syrinx for a median myelotomy which, according to clinical criteria, brought about an effective reduction in pressure from the syrinx.
Adult↗
[CT and MRT of vertebral hemangiomas].
A retrospective comparative study of CT and MRI was carried out involving 38 vertebral haemangiomas; this revealed a typical signal pattern on MRI from benign lesions. It consists of a hyper-intense signal from the bone marrow affecting the T1/T2 sequences; this may be focal or involve the entire vertebral body. These characteristic signals were compared with CT images of the spine. The areas of bone that produce the high intensity signals on MRI appear on CT as spongy patterns with hypertrophic trabeculae surrounding mostly areas with negative absorption values. An analysis of the changes in the spongiosa has revealed three clearly defined types. The signals derived from haemangiomas extending beyond the bone have an intensity of normal spongiosa; this corresponds with an absence of fat, as demonstrated by CT. Extra-osseous components have low intensity T1 signals that increase in T2 sequences.
Adult↗
[The value of MR tomography in tumorous diseases of the inner nose and paranasal sinuses].
In the examination of the inner nose and the paranasal sinuses, magnetic resonance imaging impresses by its excellent representation of anatomical structures, due above all to the multiplanar orientation of slices, the good possibility to differentiate soft tissue structures, and the accurate visualization of lymph nodes and vessels without contrast medium. Osseous lesions can be better assessed by computed tomography, however, magnetic resonance imaging can indirectly demonstrate bone destructions, too.
Adenocarcinoma↗
[Herpes encephalitis in infancy].
Since antiviral chemotherapy is available herpes encephalitis has become of great importance among viral affections of the central nervous system. Five young infants are presented with special problems of this disease and its diagnostic possibilities especially serological and imaging methods (CT scan, nuclear magnetic resonance tomography, ultrasonography of the brain) as well as electroencephalography. Clinical symptoms are very important since all those methods are not sufficient for early diagnosis and prompt onset of antiviral chemotherapy. Herpes encephalitis should be considered after apparent febrile seizures with focal symptoms as well as increasing disturbance of consciousness as manifestation of acute encephalopathy.
Acyclovir↗
[Radiologic imaging of the shoulder joint in recurrent shoulder luxation].
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Acromioclavicular Joint↗
[Comparison of MR examinations of the heart with first-pass radionuclide ventriculography].
72 patients with various heart diseases were studied by the use of magnetic resonance tomography and first-pass radionuclide angiocardiography. Both methods were compared in the RAO projection to determine the regional correspondence of morphological and functional alterations. The study proved that severe structural and functional disorders are usually combined (global correspondence for all patients 75%). Regionally, however, discrepancies between function and tissue-structure can be observed particularly in patients with anterior wall infarcts at the upper segments. Patchy signal patterns were found to correlate regionally with significant dysfunction particularly during the rapid filling phase.
Cardiomyopathy, Dilated↗
[Further development of the diagnostic possibilities of MR tomography. Combination of 3D sequences with a rapid image processing system].
Using 3-D Fourier analysis, it is possible during MR tomography to provide isotropic data of large volumes, ie. uniform spatial resolution with a voxel size of 1 mm3. If one uses a gradient echo sequence with a picture matrix of 256 X 256 X 128 voxels, then examination time is less than 15 minutes. The information contained in this enormous amount of data can be evaluated by means of rapid image analysis. The advantages of this method have been demonstrated by three examples from the head and the spine.
Adenocarcinoma↗
[New aspects in the diagnosis of intervertebral disk displacement of the upper lumbar spine with special reference to magnetic resonance tomography].
A report is presented on two patients who received surgery on a disc prolapse between the lumbar vertebrae 4 and 5 as treatment for compression of the fifth lumbar root, but in whom the clinically relevant disc prolapse was located higher (lumbar vertebrae 1/2 or thoracic vertebra 12/lumbar vertebra 1). Magnetic resonance tomography made a major contribution to the later diagnosis of the high disc prolapses. Besides precise localization of the lesion, MRT made it easier to understand why such a high disc prolapse can cause a compression syndrome of the fifth lumbar root.
Aged↗
[Imaging the spinal cord in scoliosis in magnetic resonance tomography using the 3D Fourier procedure].
Recent progress in MR-imaging allows to acquire an entire volume using 3D-Fourier-processing, resulting in an isotope spatial resolution with a voxel-size of about one cubic millimeter. Acquisition time for a matrix of 256 x 256 x 128 amounts to less than 15 minutes, if gradient-echo-sequences are applied (FLASH/FISP). The information contained in such a huge number of data is retrieved with the aid of a special rapid data processing system. Using 3D-Fourier analyses, Spinal cord is imaged very clearly even in cases of extreme kyphoscoliosis. The cord is demonstrated by arbitrary, even curved one Millimeter slices. In addition to that the acquisition of data takes only 15 minutes, which is definitely more rapid than 2D-Fourier. Details can be figured out in a very high precision. This allows to distinguish details such as vessels, small masses and nerve roots. Furthermore the signal-to-noise-ratio of 3D-sequences is higher than in multi-slice-technique. A decisive advantage is the possibility to compute curved planes in post processing of the 3D-data-sets.
Adolescent↗
[Differential diagnosis of pediatric hip pain in MR tomography].
The efficiency of spin echo tomography in the differential diagnosis of hip joint pain in children in comparison with other imaging methods was tested in 115 spin echo tomography examinations of 68 patients. By means of the different modes available it was possible to determine joint effusion, necrosed areas and the formation of abscesses with great accuracy. In the case of Legg-Calve-Perthes disease the MRT is especially in the early diagnosis superior to the other Methods, already in the early stage a classification in the four Catterall groups was possible. Furthermore the "head at risk" signs, except the gage-sign, were better to describe by BRI than by conventional x-rays. The MRT allows an exacter staging and a better observation of the course of disease, especially the beginning of the revitalisation of the femora epiphysis in earlier and clearer visible than in other imaging methods. Further diseases like epiphysial dysplasie, specific and unspecific coxitis and slipped capital femora epiphysis were also investigated. We regard spin echo examination in the differential diagnosis of hip pain in children indicated by the following criteria: 1. with over six weeks uncertain differential diagnosis of coxitis fugax and Legg-Calve-Perthes disease 2. with Legg-Calve-Perthes disease in the early stage for therapy option 3. with TBC- and non-TBC-coxitis as a therapy attend and diagnostic measure.
Adolescent↗
[Proton spin tomography in children and adolescents with so-called idiopathic scoliosis].
Somato-sensory evoked potentials (SSEP) were found to be pathological mostly in the lower extremities in 26 out of 45 children suffering from so called idiopathic scoliosis. We examined the vertebral spine and the spinal cord of 8 of them (with controlled SSEP-findings) by use of conventional MR-imaging and (where necessary) 3-dimensional-data-set following the Fournier-procedure. 6 of the 8 children showed alterations as follows: 1. A lipoma spreading partly extra-, partly intraspinally. 2. Subligamentous protrusions of the intervertebral disc (2 patients). 3. Dysraphic processes (2 patients). 4. An abnormally cranial ending myelon surrounded by a widened spinal channel. The findings are demonstrated and discussed concerning the questions whether the pathological SSEP and, furthermore, the deformity of the vertebral spine could be explained thereby. We are at least able to prove that some of the children with so called idiopathic scoliosis show pathological evoked potentials and MRI-findings.
Adolescent↗
[Transitory hip osteoporosis in magnetic resonance tomography].
Transient osteoporosis of the hip (a rare clinical picture which was difficult to diagnose up to now) shows a typical signal response in Magnetic Resonance Tomography. This enables diagnosis of the disease in a single investigation. In this way, unnecessary investigations can be avoided and therapeutic consequences can be implemented as soon as possible. Magnetic Resonance Tomography is also the most sensitive technique in order to describe the course of transient osteoporosis of the hip.
Adult↗