• The Korean Journal of Nuclear Medicine
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• v.29 no.4
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• pp.504-510
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• 1995

Avascular necrosis(AVN) of bone can be resulted from various causes that distrub vascular supply to bone tissue, including steroid therapy after renal transplantation. In this study, we determine the prevalence of the avascular necrosis of bone after renal transplantation and compare the role of the bone scan, SPECT and MRI. In 301 patients with transplanted kidney, the prevalence of avascular necrosis was deter-mined clinically. Site of bone necrosis was evaluated by clinical symptom, bone scan, SPECT and MRI. Bone scan was done in all patients with AVN. Bone SPECT and MRI were done in six cases; and MRI was done in two cases. The prevalence of AVN was 3.3% (10/301), and the site of AVN was 16 femoral heads in 10 patients (bilateral: 60%) and bilateral calcaneal tuberosity in one patient. Bone scan showed typical AVN (cold area with surrounding hot uptake) in 13 lesions, only hot uptake in three lesions (including two calcaneal tuberosities), decreased uptake in one lesion, and normal in one lesion. Decreased uptake and normal lesion showed an equivacal cold area without surrounding hot uptake on SPECT. A symptomatic patient with positive bone SPECT showed normal finding on MRI. The prevalence of AVN of bone after renal transplantation was 3.3%, and whole body bone scan showed multiple bone involvement. Two symptomatic hip Joints without definite lesion on whole body bone scan or MRI showed cold defect on SPECT. Therefore, we conclude that bone SPECT should be perfomed in a symptomatic patient with negative bone scan or MRI in case with high risk of AVN after renal transplantation.

• The Journal of the Petrological Society of Korea
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• v.25 no.3
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• pp.211-230
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• 2016

Detailed mapping along the Keumwang fault reveals a complex history of multiple brittle reactivations following late Jurassic and early Cretaceous ductile shearing. The fault core consists of a 10~50 m thick fault gouge layer bounded by a 30~100 m thick damaged zone. The Pre-cambrian gneiss and Jurassic granite underwent at least six distinct stages of fault movements based on deformation environment, time and mechanism. Each stage characterized by fault kinematics and dynamics at different deformation environment. Stage 1 generated mylonite series along the Keumwang shear zone by sinistral ductile shearing during late Jurassic and early Cretaceous. Stage 2 was a mostly brittle event generating cataclasite series superimposed on the mylonite series of the Keumwang shear zone. The roundness of pophyroclastes and the amount of matrix increase from host rocks to ultracataclasite indicating stronger cataclastic flow toward the fault core. At stage 3, fault gouge layer superimposed on the cataclasite generated during stage 2 and the sedimentary basins (Umsung and Pungam) formed along the fault by sinistral strike-slip movement. Fragments of older cataclasite suspended in the fault gouge suggest extensive reworking of fault rocks at brittle deformation environments. At stage 4, systematic en-echelon folds, joints and faults were formed in the sedimentary basins by sinistral strike-slip reactivation of the Keumwang fault. Most of the shearing is accommodated by slip along foliations and on discrete shear surfaces, while shear deformation tends to be relatively uniformly distributed within the fault damage zone developed in the mudrocks in the sedimentary basins. Fine-grained andesitic rocks intruded during stage 4. Stage 5 dextral strike-slip activity produced shear planes and bands in the andesitic rocks. ESR(Electron Spin Resonance) dates of fault gouge show temporal clustering within active period and migrating along the strike of the Keumwang fault during the stage 6 at the Quaternary period.