No abstract available.
Gait* ; Humans ; Spinal Cord Diseases*

PURPOSE: A common finding of carotid artery on magnetic resonance angiograms(MRAs) is a signal dropout along the posterior wall of carotid bulb due to reverse flow. The purpose of this study is to evaluate variable flow patterns on bifurcated carotid arterial phantoms using steady-state flow. MATERIALS AND METHODS: We designed phantoms of a bifurcated carotid artery with acrylic materials. Flow patterns were evaluated with axial and coronal imaging of MRA(2D-TOF, 3D-TOF), color Doppler imaging, and computational fluid dynamics (CFD) within the phantoms constructed of an automated closed-type circulatory system filled with 4% sugar solution. These findings were compared with findings obtained from normal volunteers. RESULTS: Axial 3D-TOF MRA images exhibited closer resemblance to the contour of the inner wall of phantoms when compared to coronal 2D-TOF MRA imaging. However, 2D-TOF MRA showed good contrast difference of signal intensities between forward flow area and reverse flow area. Dark zones with reduced signal intensities due to reversed flow were separated from the outer wall of the internal and external carotid arteries by a thin layer of forward flow along the wall on the source slice image of MRA. The general hemodynamics of the phantoms on MRA were identical to hemodynamics on color Doppler imaging and CFD. The results obtained with the phantoms matched the findings on normal volunteers. CONCLUSION: Although representations of bifurcated carotid arterial phantoms on axial 3D-TOF MRA were excellent if ideally desinged, the zone of reversed flow could be a significant factor in creating distorted image when the zone of reversed flow contacted directly with curved or deformed arterial wall.
Carotid Arteries ; Carotid Artery, External ; Healthy Volunteers ; Hemodynamics ; Humans ; Hydrodynamics ; Magnetic Resonance Angiography* ; Patient Dropouts

PURPOSE: We performed a retrospective study to compare the accuracy between conventional CT staging and intraoperative staging for advanced gastric cancer. MATERIALS AND METHODS: Sixty patients with advanced gastric cancer were included in this study during the recent 2 year-period. All were pre- and posto- peratively diagnosed as advanced gastric cancer. CTwas performed with G E 9800 and Somatom DR3 under conventional technique in 50 and with others in 10 referred patients. The CT staging for T and N category with emphasis on incurable factor, if not resacted, were performed. And we compared the accuracy between conventional CT and intraoperative staging. The final histo-pathologic staging was used as a gold standard. RESULTS: Accuracy of CT and operation for T4(n=l7) factor is 76.9 % and 86.2 % respectively. Overestimation rate for T4 was 9.3 % by CT and 6.1% by operation, and underestimation rate for was 13.8 % and 7.7 % respectively. Accuracy of CT and operation for N (n=60) factor was 50 % and 60 % respectively. Overestimation rate for N factor was 18.3 % by CT and 18.3 % by operation, and underestimation rate for N factor was 31.7 % and 21.7 % respectively. Correct Tand IM staging was possible only in 33% by CT and 38% by intraoperative assessment. CONCLUSION: Conventional CT and intraoperative staging for incurable T/N factor in advanced gastric cancer have a potential limitations, especially for N factor. Therefore, more reliable modality or technique such as dynamic scanning by spiral CT, transabdominal or endoscopic ultrasonography should be preoperatively performed to complement infrequent errors in intraoperative staging. Furthermore, a histology-oriented surgical approach seems essential in selecting the most appropriate surgical procedure.
Complement System Proteins ; Endosonography ; Fibrinogen ; Humans ; Retrospective Studies ; Stomach Neoplasms* ; Tomography, Spiral Computed

PURPOSE: The most important factor discrediting the reliability of MRAs is the overestimation of the degree of stenosis in the internal carotid artery(ICA). The purpose of this study is to evaluate the second aryhemodynamics and the cause(s) for the overestimation of the degree of variable stenotic phantoms of the carotidartery using steady-state flow on MRAs. MATERIALS AND METHODS: Using scrylic materials, normal and variable stenotic phantoms of the bifurcated carotid artery were constructed (40% and 65%). Flow patterns were evaluated with axial and coronal imaging of MRAs (2D-TOF and 3D-TOF) and DSAs of phantoms constructed from an automated closed-type circulatory system filled with 10% glucose solution. These findings were then compared with those obtained from CFD. RESULTS: 3D-TOF axial MRA of asymmetrically 40 percent stenotic phantom revealed 40 percent stenosis identical to the stenotic region of phantoms with continued poststenotic signal loss, whereas 3D-TOFzsial MRA of symmetrically 65 percent stenotic phantom showed markedly decreased signal intensity at the poststenotic segment resembling occlusion. Source image of 2D-TOF coronal MRA showed redistribution (from theinternal to external carotid artery side) of the central axis of inflow depending upon the degree of stenosis ofthe ICA ; this redistribution can be a cause of the decreased signal at the poststenotic segment, due to a reduced volume of flow through the stenotic segment. The general hemodynamics of the variable stenotic phantoms on MRA were identical to the hemodynamics on DSA and CFD. CONCLUSION: Although dephasing from turbulent flow and character of maximum intensity projection (MIP) were suggested as the main cause of the decreased poststenotic signal, our study indicated that a hemodynamically redistributed central axis of inflow and reduced flow volume through stenotic channel is one of the basic factors of the decreased signal intensity ot the poststenotic segmenton MRA.
Axis, Cervical Vertebra ; Carotid Arteries ; Carotid Artery, External ; Constriction, Pathologic* ; Glucose ; Hemodynamics*

No abstract available.
Animals ; Dizocilpine Maleate* ; Rats* ; Spinal Cord*

The authors report a rare case of aggravated myelopathy due to rebleeding of intramedullary cavernous angioma during pregnancy. A 29-year-old woman with a intramedullary cavernous angioma of the lower thoracic spinal cord was initially managed with a conservative treatment. She suffered the progressive paraparesis 16 months later during the 3rd trimester of her pregnancy. The follow-up magnetic resonance imaging revealed rebleeding of the previous cavernous angioma. The entire lesion was resected with a standard microsurgical technique after delivery, and her neurological symptoms subsequently resolved.
Adult ; Female ; Follow-Up Studies ; Hemangioma, Cavernous* ; Humans ; Magnetic Resonance Imaging ; Paraparesis ; Pregnancy* ; Spinal Cord ; Spinal Cord Diseases

PURPOSE: It has been suggested that an ulceration or hemorrhage within an atheroma on a stenotic carotid artery is a clinically important cause of transient ischemic attack(TIA). In previous studies, due to its inherent signal loss by static or turbulent flow, magnetic resonance angiography(MRA) proved to be an unreliable methed for the evaluation of subtle changes of ulceration. To improve the detectability of the ulceration within atheroma, avascular phantom was filled with gadolinium solution of various concentrations during various MR sequences. MATERIALS AND METHODS: Several vascular phantoms made of elastic silicon mimicking an ulcerated stenotic internal carotid artery(ICA) were constructed, and gadolinium solution of different concentrations (1:1000 and 1:200 of Gd-DTPA) and distilled water were introduced into the vascular phantoms using a computerized pulsatile pump. To evaluate maximum intensity projection(MIP), multiple planar reconstruction(MPR) and source images, axial and coronal images of MRA with 2D-TOF(time of flight) and 3D-TOF were reviewed. Each image of various sequences was compared with plain X-ray films of each phantom filled with barium. RESULTS: On all MR suquences, the images of the phantom of the normal carotid bifurcation were superior to the images of ulcerated and stenotic phantoms. MPR and MIP were the optimal image for detecting and defining ulceration and stenosis. Better quality images were obtained when a higher concentration of Gd-DTPA was used and when the 3D-TOF technique instead of the 2D-TOF technique was applied. CONCLUSION: This study reveals that a combination of higher concentration gadolinium with MPR and MIP on 3D-TOF technique could be optimal for the evaluation of ulceration and/or stenosis at the bifurcation of the carotid artery.
Barium ; Carotid Arteries ; Carotid Artery, Internal* ; Constriction, Pathologic ; Gadolinium ; Gadolinium DTPA ; Hemorrhage ; Magnetic Resonance Angiography* ; Plaque, Atherosclerotic ; Silicones ; Ulcer* ; Water ; X-Ray Film

Gastrointestinal involvement occurs in two thirds of children with Henoch-Schonlein purpura (HSP) and intussusception is by far the most common abdominal complication. Intussusception in HSP almost originates in the small bowel, which is in contrast with idiopathic intussusception. Earlier diagnosis and prompt treatment of intra-abdominal complications can reduce the mortality and ultrasound is the imaging modality of choice in evaluation the bowel manifestations of HSP. We report a case of jejuno-jejunal intussusception associated with HSP in a 5-year-old boy who presented with diffuse abdominal pain and vomiting after a few days of HSP onset. Abdominal ultrasound demonstrated intussusception in the jejunum with well defined target appearance because of the thickened intussusceptum, which disappeared on the computerized tomographic examination checked approximately 24 hours later. A brief review of literature was made.
Abdominal Pain ; Child ; Child, Preschool ; Diagnosis ; Humans ; Intussusception* ; Jejunum ; Male ; Mortality ; Purpura, Schoenlein-Henoch* ; Ultrasonography ; Vomiting

No abstract available.
Glucose Transport Proteins, Facilitative* ; Glucose* ; Humans ; Insulin* ; Metabolome*

OBJECTIVE: Proximal junctional kyphosis (PJK) is radiologic finding, and is defined as kyphosis of >10° at the proximal end of a construct. The aim of this study is to identify factors associated with PJK after segmental spinal instrumented fusion in adults with spinal deformity with a minimum follow-up of 2 years. METHODS: A total of 49 cases of adult spinal deformity treated by segmental spinal instrumented fusion at two university hospitals from 2004 to 2011 were enrolled in this study. All enrolled cases included at least 4 or more levels from L5 or the sacral level. The patients were divided into two groups based on the presence of PJK during follow-up, and these two groups were compared to identify factors related to PJK. RESULTS: PJK was observed in 16 of the 49 cases. Age, sex and mean follow-up duration were not statistically different between two groups. However, mean bone marrow density (BMD) and mean back muscle volume at the T10 to L2 level was significantly lower in the PJK group. Preoperatively, the distance between the C7 plumb line and uppermost instrumented vertebra (UIV) were no different in the two groups, but at final follow-up a significant intergroup difference was observed. Interestingly, spinal instrumentation factors, such as, receipt of a revision operation, the use of a cross-link, and screw fracture were no different in the two groups at final follow-up. CONCLUSION: Preoperative BMD, sagittal imbalance at UIV, and thoracolumbar muscle volume were found to be strongly associated with the presence of PJK.
Adult ; Back Muscles ; Bone Marrow ; Congenital Abnormalities ; Follow-Up Studies* ; Hospitals, University ; Humans ; Kyphosis* ; Osteoporosis ; Risk Factors* ; Sarcopenia ; Spine