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Biomedical subjects

C Hamburger

Publications and source records attributed to C Hamburger.

At least 37 records · Page 2Linked to original sources
PubMed1990

Methods and applications of three-dimensional imaging in orthopedics.

Computed tomography is a commonly used technique for detecting pathological alterations in soft tissues and the skeleton. Three-dimensional images of the skeleton are very useful for planning surgical treatment and monitoring therapy, but unfortunately mental reconstruction of complex three-dimensional anatomical structures from conventional tomography is very difficult. This article describes a process by which automated analysis of the regions of interest in the computed tomographic (CT) images yields the contours of the surfaces which can be presented pseudo-three-dimensionally using Phong's lighting model and Gouraud's shading methods. Three applications in the areas of orthopedics and neurosurgery demonstrate the efficacy of the method.

Bone Diseases↗
PubMed1989

[The importance of 111-indium marked leukocyte scintigraphy in inflammatory intracranial processes].

111-indium-labelled leukocyte scintigraphy used for testing inflammatory intracranial lesion delimitation in differential diagnosis, shows reliable results in 80% of the cases, whereas 10% demonstrate false-positive as well as false-negative results. Loss of time is caused by the 24 h waiting period for measurement, and because of supply problems. Due to these drawbacks, this method is of only limited help to the neurosurgeon in quickly finding safe pointers for determining the time of operation if inflammatory intracranial lesions are suspected. Hence, this method requires to be improved upon, or a new one should be developed.

Adult↗
PubMed1989

Noninvasive differentiation of tumors with use of localized H-1 MR spectroscopy in vivo: initial experience in patients with cerebral tumors.

A recently developed method for image-selected localized hydrogen-1 magnetic resonance (MR) spectroscopy was assessed in the differential diagnosis of nine primary and secondary cerebral tumors, including four gliomas, two meningiomas, one neurilemoma, one arachnoid cyst, and one metastasis of breast cancer. Well-resolved H-1 MR spectra of these tumors were obtained in vivo with a conventional 1.5-T whole-body MR imaging system. All tumor spectra were remarkably different from spectra from normal brain tissue. Spectra obtained from different tumors exhibited reproducible differences, while histologically similar tumors yielded characteristic spectra with only minor differences. The observed spectral alterations reflect variations in concentrations and relaxation times of the H-1 MR sensitive pool of free (mobile) metabolites within the tissues. In most cases, the concentrations of N-acetyl-aspartate and creatine/phosphocreatine are reduced below detectability, whereas choline-containing compounds are generally enhanced. The spectral differences between the tumors are mainly due to the differing concentrations of lipids, lactic acid, and carbohydrates. Localized H-1 MR spectroscopy may become an important clinical tool for the differentiation of tumors as well as for therapeutic control.

Adult↗
PubMed1987

[Diagnosis and surgical treatment of cervical intervertebral disk displacement and cervical myelopathy].

Despite the availability of excellent neuroradiological examination techniques, a decision to operate is usually still reached largely on the basis of a diagnosis of radical and/or medullary cervical compression syndrome made by clinical neurological examination. Computer tomography has allowed a decisive improvement in the diagnosis of these processes, since the position of parts of discs that have prolapsed or sequestrated dorsally or dorsolaterally relative to the spinal cord and the nerve roots can be visualized directly. Since core spin tomography does not yield information that is any more helpful in the diagnosis, despite the considerably higher level of technical sophistication and higher costs, we are of the opinion that there is no call to apply this procedure routinely for the diagnosis of medial and lateral cervical disc rupture. Since the neurological symptoms do not always allow localization of the radicular or medullary damage to the segment or segments affected, it is sometimes necessary to perform myelography with water-soluble contrast media for this purpose. The microsurgical procedures available are restricted foraminotomy for the relief of cervical nerve root compression and ventral diskectomy for the relief of spinal cord compression.

Adult↗
PubMed1979

Intracranial pressure in the cat during nitroglycerin-induced hypotension.

Intracranial pressure measurements were made during nitroglycerin-induced hypotension in the cat anesthetized with halothane. A total of 48 individual observations were made in eight animals. The administration of sufficient nitroglycerin to decrease mean arterial pressure from a control value of 87 +/- 7 torr by 12 +/- 4 torr resulted in an increase in mean intracranial pressure from a control value of 7 +/- 2 torr to 12 +/- 2 torr. Larger decreases in mean blood pressure were associated with larger increases in intracranial pressure. The increase in intracranial pressure was similar to that previously reported for nitroprusside, and greater as well as more reproducible than that reported for trimethaphan. Thus, nitroglycerin may produce significant increases in intracranial pressure, and this may be a limiting factor in its clinical use.

Anesthesia, Inhalation↗