Biomedical subjects

W Heindel

Publications and source records attributed to W Heindel.

166 records · Page 10Linked to original sources

PubMedDate not supplied

Periosteal chondroma: MR characteristics.

PURPOSE: The purpose of this study was to describe the MR characteristics of periosteal chondroma. METHOD: MR images of 12 proven cases of periosteal chondroma were analyzed with reference to tumor morphology and size. MR features were correlated with radiographic and pathologic findings. RESULTS: Tumor size ranged from 1 to 7 cm in maximum diameter with a mean value of 2.6 cm. On MR images, a soft tissue mass at the bone surface with pressure erosion of adjacent cortical bone could be identified in all cases. All lesions were bordered by a hypointense rim (100%) and frequently showed a lobulated configuration (75%). Edema of medullary bone or soft tissues was not observed in any of the cases. Signal intensity of cartilaginous tumor tissue was typically hypo-or isointense relative to muscle on T1-weighted (100%) and hyperintense relative to fat on T2-weighted (92%) and T2*-weighted (100%) MR images. Radiographically significant calcifications of the tumor matrix, present in half of the cases, caused focal signal loss on MR images of all pulse sequences. Contrast enhancement was observed predominantly at the periphery of the lesions (100%), which on pathologic examinations typically contained fibrovascular bundles, surrounding the cartilage lobules. CONCLUSION: Periosteal chondroma appears to have a relatively typical MR appearance, which reflects the histologic composition of the lesion. In addition to radiography, MRI therefore can substantially aid in the preoperative diagnosis of this rare bone lesion.

Adolescent↗

PubMedDate not supplied

Nuclear magnetic resonance (NMR) imaging in diseases of the central nervous system: initial results.

Initial experiences with Nuclear Magnetic Resonance (NMR) imaging in various intracranial diseases are reported. The images were obtained with a 0.2 Tesla resistive magnet NMR-imager of SIEMENS and the influence of different imaging techniques (spin-echo and inversion recovery) with various imaging parameters (spin-echo) on the quality and the character of the images were studied. Typical clinical examples are demonstrated and first comments are made on the quantitative evaluation of T1- and T2-relaxation times.

Adult↗

PubMedDate not supplied

Noninvasive detection of increased glycine content by proton MR spectroscopy in the brains of two infants with nonketotic hyperglycinemia.

Using localized 1H-MR spectroscopy (1H-MRS) an inborn error of metabolism within human brain could be demonstrated, while 1H-MR imaging did not show any pathologic findings like demyelination. In two children suffering from nonketotic hyperglycinemia, the proton spectrum exhibited a large glycine signal at 3.55 ppm. In patient 1 (49-day-old girl), the pathologic signal of the inhibitory neurotransmitter glycine was of similar size in the parietooccipital white matter and in the basal ganglia region. In patient 2 (a 10-day-old girl), follow-up studies within the first 4 months of life revealed a time course of cerebral glycine content that differed from the course in plasma and cerebrospinal fluid. The continuing reduction of glycine in brain tissue corresponded more reliably with clinical findings than the stable values in plasma and cerebrospinal fluid. 1H-MRS allows the noninvasive demonstration of glycine in patients with nonketotic hyperglycinemia. This new technique may be useful to control the effect of a sodium benzoate therapy by monitoring the cerebral glycine concentration directly.

Amino Acid Metabolism, Inborn Errors↗

PubMedDate not supplied

Intracerebral A lambda amyloidoma diagnosed by stereotactic biopsy.

In a 70-year-old patient with an intracerebral tumor, the very rare diagnosis of an A lambda amyloidoma has been made by stereotactic biopsy using immunohistochemistry with a panel of antibodies directed against amyloid fibril proteins of various origins. The production by an apparent benign monoclonal plasma cell proliferation with secretion of paraproteins into the cerebrospinal fluid is assumed. It is the 4th case in which the amyloid protein was classified as derived from immunoglobulin lambda-light chains and, to our knowledge the first in which an A lambda amyloidoma has been diagnosed intra vitam. The amyloid is restricted to the brain and no systemic involvement has been detected. Therapeutic procedures are discussed.

Aged↗