Information processing in nuclear magnetic resonance imaging.

An extended image analysis and classification system is presented to discuss the principal composition of the components as well as the methods of its realization in the field of reference based NMR diagnostics and tissue characterization.

[Results of nuclear magnetic resonance tomography studies in endocrine orbitopathy].

Magnetic resonance imaging (T1- and T2-weighted) was performed in 65 patients with Graves' disease. In addition, T2 relaxation times of each ocular muscle were measured. Of the muscles thus studied, 54.

Tissue characterization of benign brain tumors: use of NMR-tissue parameters.

To evaluate the potentials of NMR tissue parameters for tissue characterization we investigated 68 patients with benign brain tumors. Tissue parameters were accurately measured by a recently developed interlaced triple sequence. Each individual tumor was characterized by a set of three numbers (relaxation times T1 and T2 and proton density Rho).

Magnetic resonance imaging of dysraphic myelodysplasia. Findings in 56 children and adolescents with postrepair meningomyelocele.

The spinal cord in 56 children and adolescents was examined by magnetic resonance imaging (MRI) many years after neonatal surgery on a meningomyelocele (average age 12 years). In a high percentage of cases, the diagnosis "tethered cord" was made. Associated anomalies were found with a frequency of 21%.

[Therapy of endemic goiter with levothyroxine and iodide. A multicenter study].

74 patients suffering from diffuse endemic goitre and with peripheric euthyrotic metabolism were treated for 6 months either with 150 micrograms levothyroxine (T4) daily (group I, n = 35), or with a combination of 100 micrograms levothyroxine and 130.8 micrograms potassium iodide (corresponding to 100 micrograms iodide) daily (group II, n = 39). This was followed in each case by a 3-month prophylactic administration of 100 micrograms iodide daily.

Errors in T1-determination using multislice technique and Gaussian slice profiles.

Multislice SE- or IR-sequences with different TR- and T1-times, respectively, are often used, to determine T1- and T2-values for tissue characterisation. To investigate the perturbating influence of the sequential excitation in multislice technique, we measured the signal intensities and calculated the T1-values of phantoms as a function of gap widths between neighboured slices. Phantoms contained fluids of different T1.

[Reference substance for initialling the marker space in NMR tomography].

Dimethylsiloxane polymers are tested to serve as a reference medium in quantitative MR imaging. Simultaneously measured during the patient's examination, the reference data are used to normalize the intrinsic MR tissue parameters. This method helps to achieve interindividual comparability of tissue vectors which are defined by proton density, spin-spin and spin-lattice relaxation times, thus leading to a remarkable improvement in tissue classification.

MRI in cranial tuberculosis.

A case of multiple intracranial tuberculomas is presented. CT and MRI findings are discussed and compared. MRI showed multiple tuberculomas characterised by the same signal intensity as the surrounding brain parenchyma.

[MR tomography in glioblastomas and cerebral metastases].

36 Patients with glioblastomas (17 cases) and cerebral metastases (19 cases) were investigated by MRI. The typical signal behavior at different acquisition parameters (T1-, T1/T2-, Rho- and Rho/T2-weighted) was analysed using an interlaced triple sequence. In most cases the NMR-tissue parameter T1, T2 and proton-density (Rho) were determined to evaluate the potentials for tissue characterisation.

[Potentialities of MR tomography in monitoring the therapy of malignant bone tumors].

The value of MRI as a method for controlling treatment quantitatively was studied in four osteosarcomas and one Ewing sarcoma. Histologically proven change resulting from chemotherapy (2 patients) correlated with a significant increase in T2 of tumour tissue. In three other patients who did not respond to therapy, no change could be demonstrated.

[MR tomography of benign brain tumors].

69 Patients with benign brain tumours were examined via MRI (30 meningiomas, 17 pituitary adenomas, 14 acoustic neuromas, and 8 craniopharyngiomas). Typical morphological characteristics and values of the MR tissue parameters (T1, T2, Rho) are presented. The combined analysis of tissue parameters and morphological details allows a satisfying differentiation between different pathohistological entities.

[MRT in neurofibromatosis and tuberous sclerosis].

The relatively rare neurocutaneous syndromes may produce neurological symptoms during childhood. After closure of the fontanelle, the radiological methods of choice are CT and MRT. The value of these two methods is demonstrated by twelve examples (eight neurofibromatoses, four tuberous scleroses).

[MR tomography in intracranial meningiomas].

The typical findings of intracranial meningiomas seen in 24 patients are described. The signal intensities at different acquisition parameters are analysed and optimal pulse sequences derived from these data. In 90% of the patients MR-tissue parameters were measured and correlated with the histological findings.

[Initial clinical results of tissue characterization by T1, T2 and proton density in nuclear magnetic resonance tomography].

The NMR parameters (proton density, relaxation times T1 and T2) have been assessed by Carr-Purcell-Meiboom-Gill (CPMG) spin echo sequences. A computer assisted analysis of the data of 21 patients with cerebral tumours allowed a classification of tumour tissue in different tumours. The use of quantitative procedures for tissue characterisation allows the differentiation of benign and malignant brain tissue by characteristic colour coding demonstrating morphological details like tumour, edema and necrosis as well as indicating the histological types of the tumours of the central nervous system.

[Long-term studies of children following therapy of brain tumors using nuclear magnetic resonance tomography and ultrasound].

Within two and a half years 82 magnetic resonance imaging and 155 ultrasound examinations were performed in 46 children after treatment for brain tumors. In 42 cases the primary tumors were located in the posterior cranial fossa. Magnetic resonance imaging required sedation in 14 and anesthesia in 3 children.

[MR tomography in parenchymatous neurocysticercosis].

MRI-findings in a case of parenchymal neurocysticercosis are presented. The changes of the lesions as a response to chemotherapy were monitored by MRI and CT. Problems of sensitivity (MRI vs.

NMR follow-up studies of CNS-tumors in infancy and childhood.

Sixteen children with brain tumors, fifteen of which were located in the posterior cranial fossa, were followed-up postoperatively with NMR. Four recurrences of medulloblastoma and one recurrence of an ependymoma were found. Three children showed signs of known therapeutic sequelae such as hygroma, atrophy and dilatation of the subarachnoid space.