PURPOSE: To know the possibility of clinical application of MRI using oxygen inhalation as a perfusion MRI. MATERIALS AND METHODS: Two healthy volunteers and three patients of one moyamoya disease, one acute infarction and one meningioma were studied using a 1.5 Tesla MRI unit. Oxygen (15 liters/min) mixed with room air was given using face mask from 8 second to 35 second during the study. Images were acquired 25 times (scan time per study were 1.6 seconds) using susceptibility contrast EPI (echo planar image) sequence. Difference maps were acquired by early (study 12-18), and late (study 19-25) O2 inhalation image groups minus pre-O2 inhalation image group (study 3-9) with a Z-score of 0.7-1.0 using VB31C program of Magnetom Vision. The resulting perfusion images were created by superimposition of difference maps on corresponding T1 weighted anatomic images. On moyamoya patient, similar perfusion images were acquired after Gd-DTPA injection, and compared with O2 inhalation perfusion images. RESULTS: The author can get the perfusion images of the brain by oxygen inhalation with susceptibility contrast EPI sequence at the volunteers, and the patient of moyomoya disease, acute infarction and meningioma. On moyamoya patient, perfusion images with O2 inhalation are similar with perfusion images by Gd-DTPA injection. CONCLUSION: This study has demonstrated that the susceptibility contrast EPI by oxygen inhalation can be used as the clinically useful perfusion MRI technique.
Acute Disease ; Brain* ; Gadolinium DTPA ; Healthy Volunteers ; Humans ; Infarction ; Inhalation* ; Magnetic Resonance Imaging* ; Masks ; Meningioma ; Moyamoya Disease ; Oxygen* ; Perfusion* ; Volunteers

PURPOSE: To evaluate the usefulness of comparison of the signal intensity of uterine septum in the differential diagnosis of bicornuate and septate uterus on magnetic resonance (MR) imaging. MATERIALS AND METHODS: Preoperative MR imaging findings of surgically proven 5 bicornuate and 6 septate uteri were retrospectively analyzed. Because preoperative differential diagnosis of both was possible in all cases in terms of the intercornual distance, external contour of uterine fundus, and divergent angle of two uterine cavities, these criteria were excluded in this study. The signal intensity of uterine septum in patients with bicornuate and septate uterus was analyzed on T1-weighted and fast spin echo T2-weighted images obtained in the axial and coronal planes, using a 1.5-T MR scanner. The signal intensity of uterine septum especially on T2-weighted images was compared with that of myometrium or junctional zone. RESULTS: The signal intensity of uterine septum in patients with bicornuate uterus (n=5) and septate uterus (n=6) was similar to that of myometrium in all cases on T1-weighted images. The septum of bicornuate uterus (n=5) on fast spin echo T2-weighted images was isointense with myometrium in three and hypointense in two cases. The uterine septum of septate uterus (n=6) on T2-weighted images was isointense with myometrium in two, hypointense in two, and isointense with or more hypointense than junctional zone in two cases. No patient showed different signal intensity between upper and lower uterine septum. CONCLUSION: Because the MR signal intensity of the uterine septum in bicornuate or septate uterus is variable, it should not be used alone in the differential diagnosis of them. In these clinically important differentiation, therefore, comprehensive analysis of MR findings in terms of the external contour of uterine fundus, intercornual distance, divergent angle of two uterine cavities, in addition to the signal intensity of the uterine septum, should be considered.
Animals ; Diagnosis, Differential* ; Female ; Humans ; Magnetic Resonance Imaging ; Mice ; Myometrium ; Retrospective Studies ; Uterus*

PURPOSE: To evaluate the effect of global scaling analysis on brain activation for sensory and motor func-tional MR imaging study. MATERIALS AND METHODS: Four normal subjects without abnormal neurological history were included. Arm extension-flexion movement was used for motor function and 1 KHz pure tone stimulation was used for auditory function. Functional magnetic resonance imaging was performed at 3T MRI (GE, Milwaukee, USA) using BOLD-EPI technique and SPM2 was employed for data analysis. On data analysis, the brain activation images were obtained with and without global scaling by fixing other parameters such as motion correction and realignment. RESULTS: The difference in brain activation between no scaling and global scaling was not large in case of right upper extremity movement (p<0.000001). For auditory test, brain activation with global scaling showed larger activation than that of without global scaling (p<0.05). CONCLUSION: A caution must be taken into account when analyzing functional imaging data with global s-caling especially for functional study of small local BOLD signal change.
Arm ; Brain ; Magnetic Resonance Imaging* ; Statistics as Topic ; Upper Extremity

PURPOSE: To evaluate the NMR relaxation properties of newly developed high performance paramagnetic. MATERIALS AND METHODS: 4-aminomethylcyclohexane carboxylic acid (0.63 g, 4 mmol) was mixed with the suspension solution of DMF (15 mL) and DTPA-bis-anhydride (0.71 g, 2 mmol) to synthesize the ligand. The ligand was then mixed with Gd2O3 (0.18 g, 0.5 mmol) to synthesize Gd-chelate. For the measurement of magnetic relaxivity of paramagnetic compounds, the compounds were diluted to 1mM and then the relaxation times were measured at 1.5T(64 MHz). Inversion-recovery pulse sequence was employed for T1 relaxation measurement and CPMG(Carr-Purcell-Meiboon-Gill) pulse sequence was employed for T2 relaxation measurement. Using MATLAB(Version 7.1) program, T1 magnetic relaxation map, R1 map, T2 magnetic relaxation map and R2 map were developed to represent magnetic relaxation time and magnetic relaxivity as image. RESULTS: Compared to R1=4.9 mM(-1) sec(-1) and R2= 4.8 mM(-1) sec(-1) of Omniscan (Gadodiamide), which is commercially available paramagnetic MR agent, R1 of SUK090(Gd-C32H74N5O24) was 12.46 mM(-1) sec(-1) and R1 of SUK091(Gd-C34H78N5O24) was 12.77 mM(-1) sec(-1). However, R1 of SUK092(Gd-C30H56N5O17) was decreased to 2.09 mM(-1) sec(-1). In case of R2, SUK090(Gd-C32H74N5O24) was 8.76 mM(-1) sec(-1) and SUK091(Gd-C34H78N5O24) was 7.60 mM(-1) sec(-1) whereas SUK092(Gd-C30H56N5O17) CONCLUSION: Among three new paramagnetic complexes, SUK090(Gd-C32H74N5O24) and SUK091(Gd-C34H78N5O24) showed higher T1, T2 magnetic relaxation rates than that of commercially available paramagnetic MR agent and thus expected to have more contrast enhancement effect.
Relaxation*

Synovial sarcoma is rare soft tissue tumor mesenchymal origin. Osseous involvement of synovial sarco-ma is rare. A 24-year-old man presented with pain and swelling of the lower extremity. MRI of the lower extremity demonstrated a large mass encircling tibia with osseous involvement. Surgical excision of the mass was done and the mass was diagnosed as biphasic synovial sarcoma with bone marrow involvement. We also discuss the other imaging findings of synovial sarcoma on MRI.
Bone Marrow ; Extremities ; Humans ; Lower Extremity ; Magnetic Resonance Imaging ; Sarcoma ; Sarcoma, Synovial* ; Tibia ; Young Adult

PURPOSE: To describe MR imaging features of hypoxic brain damage in relation to time elapse and prog-nosis of patients. MATERIALS AND METHODS: We reviewed 19 MR studies of 18 patients with hypoxic brain damage. MR imaging studies were performed between 1 to 20 days after the hypoxic insults (mean 8.6 days). MR images were analyzed with regard to the locations of abnormal signal intensities, the presence of brain edema. And imaging findings were correlated with the time elapse after the insults and the prognosis of patients. RESULTS: On 19 cases of MR studies, abnormal high intensities on T2-weighted images were found in the basal ganglia (15, 78.9%), cerebral cortex (13, 68.4%), white matter (9, 47.4%), thalamus (6, 31.6%), cerebellum (4, 21.1%) and brainstem (1, 5.3%), respectively. Cerebral cortical involvement was typically bilateral and diffuse, but sometimes limited to the parieto-occipital area. The brainstem and cerebellar involvement was rare and in all cases, cerebral cortical lesions accompanied. Most of the white matter lesions were accompanied with cortical and deep gray matter lesions and found in subacute period(>6 days). The cortical high signal intensity lesions on T1-weighted image were found mostly in subacute stage, but in some cases involvement was also found in acute stage (< or =6 days). The cortical edema is found on 11 cases in acute and subacute stages. In cases of recovered consciousness, cortical involvement and edema on MR were rare. CONCLUSION: MR findings of hypoxic brain damage were various, but diffuse bilateral involvement of cortex and/or deep gray matter was found in most of the cases. White matter involvement was rarely found in acute stage and usually found in subacute stage. In cases of good pronosis, cortical involvement and edema were rare.
Anoxia ; Basal Ganglia ; Brain ; Brain Edema ; Brain Stem ; Cerebellum ; Cerebral Cortex ; Consciousness ; Edema ; Humans ; Hypoxia, Brain* ; Magnetic Resonance Imaging ; Prognosis* ; Thalamus

PURPOSE: Recent development of diffusion tensor imaging enables the evaluation of the microstructural characteristics of the brain white matter. However, optimal imaging parameters for diffusion tensor imaging, particularly concerning the number of diffusion gradient direction, have not been studied thoroughly yet. The purpose of this study was to evaluate the influence of the number of diffusion gradient direction on the fiber tracking of the white matter. MATERIALS AND METHODS: 13 healthy volunteers (ten men and three women, mean age 30 years, age range 23-37 years) were included in this study. Diffusion tensor imaging was performed with different numbers of diffusion gradient direction as 6, 15, and 32, keeping the other imaging parameters constant. The imaging field ranged from 1 cm below the pons to 2-3 cm above the lateral ventricle, parallel to the anterior commissure-posterior commissure line. FA (fractional anisotropy) maps were created via image post-processing, and then FA and its standard deviation were calculated in the genu and the splenium of the corpus callosum on each of FA maps. Fiber tracking of the corticospinal tract in the brain was performed and the number of the reconstructed fibers of the tract was measured. FA, standard deviation of FA and the number of the reconstructed fibers were compared statistically between the different diffusion gradient directions. RESULTS: FA is not statistically significantly different between the different diffusion gradient directions. By increasing the number of diffusion gradient direction, standard deviation of FA decreased significantly, and the number of the reconstructed fibers increased significantly. CONCLUSION: The higher number of diffusion gradient direction provided better quality of fiber tracking.
Anisotropy* ; Brain ; Corpus Callosum ; Diffusion Tensor Imaging ; Diffusion* ; Female ; Healthy Volunteers ; Humans ; Lateral Ventricles ; Magnetic Resonance Imaging* ; Male ; Pons ; Pyramidal Tracts

PURPOSE: Numerous studies have been performed about the various safety consideration of magnetic resonance(MR). Multiple investigators have failed to reveal any deleterious defects of MR. On the other hand, several studies have demonstrated detectable biologic effects of high-field MR produces any morphologic changes on the cell membrane and intracellular ultrastructures in human peripheral blood lymphocytes in vitro. MATERIALS AND METHODS: Lymphocytes were isolated from peripheral blood of normal human adults by Ficoll-Hypaque density centrifugation. Exposure to MR was performed with 4.69T and 11.74T MR spectrometer with a radio frequency(RF) pulse of 200MHz and 500MHz. Exposure times varyed from 30 minutes to 3 hours. The cells were fixed immediately, 1, 3, 7 days after MR exposure. Morphologic evaluation was examined by transmission electron microscopy(TEM). RESULTS: Under TEM there was cell transformation including cellular membrane, nucleus and intracellular microorganelles on lymphocytes exposed to MR. The percentage of transformed lymphocytes was not significantly increased after 4.69T MR exposure, whereas the percentage of transformed lymphocytes was significant increased after 11.74T MR exposure(P<0.05) compared with that of control. The percentage of transformed lymphocytes was significantly increased at the long incubation period in control and MR exposure group(P<0.05). No change according to MR exposure time and RF pulse sequence was noted. CONCLUSION: Exposure to high-field MR induces morphologic transformations of lymphocytes in vitro. Additional studies have to be performed before definitive conclusion can be reached about the safety of high-field MR.
Adult ; Cell Membrane ; Centrifugation ; Hand ; Humans* ; Lymphocytes* ; Membranes ; Research Personnel

PURPOSE: Traumatic rupture of the diaphragm is not easy to diagnose and often delayed. Delayed diagnosis of diaphragmatic rupture accompanied by higher chances of strangulation of herniated viscera which may result in higher morbility and mortality. The purpose of this study was to evaluate diagnostic accuracy of spiral CT, MRI and US for the diagnosis of diaphragmatic rupture in an animal model. MATERIALS AND METHODS: Small, medium, and large sized transabdominal diaphragmatic ruptures were surgically made in experimental rabbits and then followed up with spiral CT, MRI, and US at 1 day, 3 day, and 1 week after operation. RESULTS: US was superior to MRI or spiral CT in diagnosis of diaphragmatic rupture(P<0.05). The sensitivity and specificity were 94.4% and 92.9% for US, 54.0% and 85.7% for MRI, and 46.0% and 78.6% for spiral CT, respectively. The size of laceration was not related to diagnostic sensitivity in US. Sensitively of MRI and spiral CT increased as the size of laceration were larger, but no statistical significant was present(P>0.05). All experimental animals developed pleural effusion or hemothorax one day after operation. In acute phase. US and MRI were more sensitive than spiral CT in detecting diaphragmatic rupture. Spinal CT was more sensitive than US and MRI in delayed phase but without statistical significance(P>0.05) In the experimental rabbits with accompanying visceral hernia through the diaphragmatic defect, diagnostic accuracy was found equally high among three image modalities(P>0.05). CONCLUSION: This study indicates that US is the most accurate diagnostic method in detecting injury to the diaphragm in a rabbit model. The findings obtained in this experimental study can be applied to the diaphragmatic rupture of human being.
Animals ; Delayed Diagnosis ; Diagnosis* ; Diaphragm ; Hemothorax ; Hernia ; Humans ; Lacerations ; Magnetic Resonance Imaging ; Models, Animal ; Mortality ; Pleural Effusion ; Rabbits ; Rupture* ; Sensitivity and Specificity ; Tomography, Spiral Computed* ; Ultrasonography* ; Viscera

PURPOSE: To evaluate the diagnostic role of a three-dimensional MR cholangiopancreatography(MRCP) over endoscopic retrograde cholangio- pancreatography(ERCP) in various extrah-epatic biliary disease. MATERIALS AND METHODS: MRCP and ERCP were performed in 45 consecutive patients with suspected extrahepatic biliary diseases. MRCP was obtained using a reverse fast imaging with a steady-state free precession (reverse FISP : PSIF) sequences, and then images were reconstructed by standard MIP algorithm. The predictability of biliary dilatation and level of obstruction of MRCP was evaluated using ERCP as a gold standard. The accuracy distinguishing malignant from benign lesions, and overall diagnostic accuracy were compared between MRCP and ERCP. RESULTS: The sensitivity, specificity and accuracy of MRCP in predicting biliary dilatation were 94.6%, 75.0% and 91.1%, respectively. The level of obstruction was accurate in 87.0% with MRCP. The sensitivity, specificity and accuracy MRCP and ERCP in distinguishing malignant from benign lesions were 76.2%, 87.5% and 82.2% and 71.4%, 83.3% and 77.8%, respectively. The overall diagnostic accuracy was 60.0% with MRCP and 55.6% with ERCP. CONCLUSION: 3D MRCP shows a good diagnostic value compared to that of ERCP, and can replace a ERCP.
Cholangiopancreatography, Endoscopic Retrograde* ; Dilatation ; Humans ; Sensitivity and Specificity