OBJECTIVE : Bone mineral density is influenced by genetic, hormonal and exogenous factor that adversely affect peak mineral density include cigarette smoking, physical disability, poor calcium intake and certain medication include steroid and anticonvulsant drugs. We studied epileptic children receiving 6months above, to document change of bone mineral density by anticonvulsant drugs. METHODS: From July 1, 1996 to September 1, 1996 lumbar bone mineral density was measured by dual-energy X-ray absorptiometry in 27 children treated with anticonvulsant drugs 6months above (age ranged : 4-13 year) in Soonchunghyang University hospital. The subjects were classified into 3 groups : treated with carbamazepine alone, valproate alone and combined group. RESULTS: 1) Mean age of carbamazepine group was 10.2+/-2.42yrs(6-l4yr), duration of therapy was 22.1+/-13.9 months(6-44 months), mean value of bone mineral densities were 0.668+/-0.128g/cm2(0.548-0.927). Though it was lower than control group in 8, 9, 10, 12, 13 year, had not statistical significance. 2) Mean age of valproate group was 9.8+/-2.92yrs(6-l3yr), duration of therapy was 40.5 +/-22.2months(17-79month), mean value of bone mineral densities were 0.618+/-0.097g/cm2(0.516-0.788). Though it was lower than control group in 7, 10, 13 year, had not statistical significance. 3) Mean age of combined group was 7.9+/-3.2yrs(4-l4yr), duration of therapy was 37.5 +/-24.7months(12-88month), mean value of bone mineral densities were 0.602+/-0.109 g/cm2(0.552-0.807). Though it was lower than control group in 7, 8, 10 year, had not statistical significance. CONCLUSION: Because growing children is more sensitive than adult, in case of receiving long-term anticonvulsant therapy, it is important that early detection and prevention of abnormal bone mineralization by appropriate monitoring.
Absorptiometry, Photon ; Adult ; Anticonvulsants* ; Bone Density* ; Calcification, Physiologic ; Calcium ; Carbamazepine ; Child* ; Humans ; Smoking ; Valproic Acid

No abstract available.
Animals ; Liver* ; Rats*

No abstract available.
Animals ; Liver* ; Rats*

Image-guided localized, water-suppressed in vivo 1H MR spectroscopic studies were performed on the brain tumors in 3 patients. In all 3 patients, in vivo 1H MR spectra in brain neoplastic tissues revealed that the signal intensities of N-acetylaspartate (NAA) choline (Cho) resonances were decreased and increased, respectively, comparing with healthy normal tissue. A distinct lactate signal was identified in all three patients. A ratio that the observed metabolite alterations from localized, water-suppressed in vivo 1H MR spectroscopy can be useful as an index of brain tumors, and that the technique is clinically to highlight as one promising modalities in brain tumors for more accurate diagnosis.
Brain Neoplasms* ; Brain* ; Choline ; Diagnosis ; Humans* ; Lactic Acid ; Magnetic Resonance Spectroscopy*

Radiosurgery is a highly precise form of radiation therapy for the treatment of vascular lesions, certain primary or metastatic neoplasms, or functional disorders. Either intracranial or extracranial, which are inaccessible or unsuitable for surgical or other management. As the basis of radiation physics for radiosurgery, this article introduces radiation history, the method of radiation production, interaction mode of radiations with human, transfer of radiation energy to the tissue, and dose planning to generate a desirable dose distribution on the target site. Biologically, the goal of radiosurgery is to cause a precise damage only to the limited tissue within the target volume without exceeding the acceptable rate of complications. As the therapeutic ratio is a function of the volume irradiated, the total dose and dose per fraction used, and the level of acceptable risk, radiation oncologists or practitioners should consider various radiobiologic factors when using radiosurgery to obtain the maximum therapeutic ratio.
Humans ; Radiobiology ; Radiosurgery

In vivo 1H MR spectroscopic studies were performed on the human brain in six normal volunteers. Some distinct proton metabolites, such as N-acetylaspartate (NAA), creatine/phosphoccreatine (Cr), choline/phosphocholine (Cho), myo-inostitol (Ins) and lipid (fat) were clearly identified in normal brain tissues. The signal intensity of NAA resonance is strongest. The standard ratios of metabolites from the normal brain tissues in specific regions were obtained for the references of further in vivo 1H MR spectroscopic studies. Our initial results suggest the in vivo 1H MR spectroscopy may provide more precise diagnosis on the basis of the metabolic informations on brain tissues. The unique ability of in vivo 1H MR spectroscopy to offer noninvasive information about tissue biochemistry in patients will stimulate its impact on clinical research and disease diagnosis.
Biochemistry ; Brain* ; Diagnosis ; Healthy Volunteers* ; Humans* ; Magnetic Resonance Spectroscopy* ; Protons

Since LINAC-based stereotactic radiosurgery uses multiple noncoplanar arcs, three-dimensional dose evaluation and many beam parameters, a lengthy computation time is required to optimize even the simplest case by a trial and error. The basic approach presented in this paper is to show promising methods using an experimental optimization and an analytic optimization. The purpose of this paper is not to describe the detailed methods, but introduce briefly, proceeding research done currently or in near future. A more detailed description will be shown in ongoing published papers. Experimental optimization is based on two approaches. One is shaping the target volumes through the use of multiple isocenters determined from dose experience and testing. The other method is conformal therapy using a beam's eye view technique and field shaping. The analytic approach is to adapt computer-aided design optimization in finding optimum irradiation parameters automatically.
Computer-Aided Design ; Radiosurgery*

PURPOSE: To evaluate the various phosphorus metabolism' of breast tumors with use of in vivo phosphorus-31 (31P) M R spectroscopy (MRS) MATERIALS AND METHODS: Five patients with breast tumor (benign in two, malignant in three) and three normal healthy volunteers participated in this study. All in vivo31P MRS examinations were performed on 1.5 Twhole-body MRI/MRS system by using a Free Induction Decay (FID) pulse sequence. Tl-weighted MR images were used for localization of tumors. Peak areas for each phosphorus metabolite were measured using a Marquart algorithm. RESULTS: Breast carcinoma had a substantially larger phosphomonoester (PME) and a smaller phosphocreatine (PCr) peak intensity than normal breast tissue. This was reflected in the relatively higher PME/PCr ratio of breast carcinomas as well as phosphodiester (PDE)/PCr, inorganic phosphate (Pi)/PCr, and adenosine triphosphate (ATP)/PCr ratios, compared with normal controls. The mean pH value of breast tumor demonstrating the alkaline nature was higher than that of normal controls. Spectral patterns between benign breast disease and normal breast tissue were quite similar, and differentiation was not established. CONCLUSION: Our preliminary study suggests that in vivo 31P MRS is a noninvasive examination which may be useful in the early differentiation of malignant breast tumors from normal and benign conditions. However, normal control and benign conditions could not be characterized on the basis of the phosphorus metabolite ratios.
Adenosine Triphosphate ; Breast Diseases ; Breast Neoplasms* ; Breast* ; Healthy Volunteers ; Humans ; Hydrogen-Ion Concentration ; Magnetic Resonance Spectroscopy* ; Phosphocreatine ; Phosphorus ; Spectrum Analysis

No abstract available.
Kidney Transplantation* ; Pancreatitis*

PURPOSE: To evaluate the spatial distribution of various proton metabolites in the human brain with use of water-suppressed in vivo 1H MR spectroscopic imaging (MRSI) technique MATERIALS AND METHODS: All of water-suppressed in vivo 1H MRSI were performed on 1.5 T whole-body MRI/MRS system using Stimulated Echo Acquisition Method (STEAM) Chemical shift Imaging (CSI) pulse sequence. T1 -weighted MR images were used for CSl Field Of View (FOV; 24 cm). Voxel size of 1.S cm3 was designated from the periphery of the brain which was divided by 1024 x 16 x 16data points. RESULTS: Metabolite images of N-acetylaspartate (NAA), creatine/phosphocreatine (Cr) + choline/phosphocholine (Cho), and complex of gamma-aminobutyric acid (GABA) -I- glutamate (Glu) were obtained on the human brain. CONCLUSION: Our preliminary study suggests that in vivo 1H MRSl could provide the metabolite imaging to compensate for hypermetabolism on Positron Emission Tomography (PET) scans on the basis of the metabolic informations on brain tissues. The unique ability of in vivo 1H MRSI to offer noninvasive informations about tissue biochemistry in disease states will stimulate on clinical research and disease diagnosis.
Biochemistry ; Brain* ; Diagnosis ; gamma-Aminobutyric Acid ; Glutamic Acid ; Humans* ; Magnetic Resonance Imaging ; Positron-Emission Tomography ; Protons