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: To evaluate the differences of functional imaging patterns between conventional spoiled gradient echo(SPGR) and echo planar imaging(EPI) methods in cerebral motor cortex activation. MATERIALS AND METHODS: Functional MR imaging of cerebral motor cortex activation was examined on a 1.5T MR unit with SPGR (TR/TE/flip angle=50ms/40ms/30degree, FOV=300mm, matrix size=256x256, slice thickness=5mm) and an interleaved single shot gradient echo EPI (TR/TE/flip angle=3000ms/40ms/90 degree, FOV=300mm, matrix size=128x128, slice thickness=5mm) techniques in five male healthy volunteers. A total of 160 imaging in one slice and 960 images in 6 slices were obtained with SPGR and EPI, respectively. A right finger movement was accomplished with a paradigm of an 8 activation/ 8 rest periods. The cross-correlation was used for a statistical mapping algorithm. We evaluated any differences of the time series and the signal intensity changes between the rest and activation periods obtained with two techniques. Also, the locations and areas of the activation sites were compared between two techniques. RESULTS: The acivation sites in the motor cortex were accurately localized with both methods. In the signal intensity changes between the rest and activation periods at the activation regions, no significant differences were found between EPI and SPGR. Signal to noise ratio (SNR) of the time series data was higher in EPI than in SPGR by two folds. Also, larger pixels distributed over small p-values at the activation sites in EPI. CONCLUSIONS: Good quality functional MR imaging of the cerebral motor cortex activation could be obtained with both SPGR and EPI. However, EPI os preferable because it provides more precise information on hemodynamics related to neural activities than SPGR due to high sensitivity.
Fingers ; Healthy Volunteers ; Hemodynamics ; Humans ; Magnetic Resonance Imaging* ; Male ; Motor Cortex* ; Signal-To-Noise Ratio

PURPOSE: To investigate the localization and functional lateralization of the supplementary motor area (SMA) in motor activation tests in comparison to that of the primary motor area. MATERIALS AND METHODS: Seven healthy volunteers obtained echoplanar imaging blood oxygen level dependent technique. This study was carried on 1.5T Siemens Magneton Vision system with the standard head coil. Parameters of EPI were followed as ; TR/TE; 1.0/66.0 msec. flip angle : 90degree, field of view : 22cmx22cm, matrix : 128x128, slice number/slice thickness/gap : 10/4mm/0.8mm with fat suppression technique. Motor task as finger opposition in each hand consisted of 3 sets of alternative rest and activation periods. Postprocessing were done on Stimulate 5.0 by using cross-correlation statistics. To compare the functional lateralization of the SMA in the right and left hand tests, each examination was evaluation for the percent change of signal intensity and the number of activated voxels both in the SMA and in the primary motor area. Hemispheric asymmetry was defined as difference of summation of the activated yokels between each hemisphere. RESULTS: Percent change of signal intensity in the SMA (2.49-3.06%) is lower than that of primary motor area(4.4-7.23%). Percent change of signal intensity including activated voxels were observed almost equally in the right and left SMA. As for summation of activated voxels primary motor area had significant difference between each hemisphere but not did the SMA. CONCLUSION: Preferred contralateral dominant hemisphere and hemispheric asymmetry were detected in the primary motor area but not in the SMA.
Echo-Planar Imaging ; Fingers ; Hand* ; Head ; Healthy Volunteers ; Magnetic Resonance Imaging* ; Oxygen

PURPOSE: There have been some efforts to diagnose intracranial aneurysm through a non-invasive method using MRA, although the process may be difficult when the lesion is less than 3mm. The present study prospectively compare the results of high resolution, fast speed slice interpolation MRA and DSA therapy examing the potentiality of primary non-invasive screening test. MATERIALS AND METHODS: A total of 26 cerebral aneurysm lesions from 14 patients with subarachnoid hemorrhage from ruptured aneurysm (RA) and 5 patients with unruptured aneurysm(UA). In all subjects, MRA was taken to confirm the vessel of origin, definition of aneurysm neck and the relationship of the aneurysm to nearby small vessels, and the results were compared with the results of DSA. The images were obtained with 1.5T superconductive machine(Vision, Siemens, Erlangen, Germany) on 4 slabs of MRA using slice interpolation. the settings include TR/TE/FA=30/6.4/25, matrix 160x512, FOV 150x200, 7minutes 42seconds of scan time, effective thickness of 0.7mm and an entire thickness of 102.2mm. The images included structures from foramen magnum to A3 portion of anterior cerebral artery. MIP was used for the image analysis, and multiplanar reconstruction(MPR) technique was used in cases of intracranial aneurysm. RESULTS: A total of 26 intracranial aneurysm lesions from 19 patients with 2 patients having 3 lesion, 3 patients having 2 lesions and the rest of 14 patients having 1 lesion each were examined. Among those, 14 were RA and 12 were UA. Eight lesions were less than 2mm in size, 9 lesions were 3-5mm, 7 were 6-9mm and 2 were larger than 10mm. On initial exams, 25 out of 26 aneurysm lesions were detected in either MRA or DSA showing 96% sensitively. Specificity cannot be estimated since there was no true negative of false positive findings. When MRA and MPR were used concurrently for the confirmation of size and shape, the results were equivalent to those of DSA, while in the confirmation of aneurysm neck and parent vessels, the concurrent use of MRA and MPR was far superior to the sole use of either MRA or DSA. CONCLUSION: High resolution MRA using slice interpolation technique showed equal results as those of DSA for the detection of intracranial aneurysm, and may be used as a primary nin-invasive screening test in the future.
Aneurysm ; Aneurysm, Ruptured ; Angiography* ; Angiography, Digital Subtraction* ; Anterior Cerebral Artery ; Foramen Magnum ; Humans ; Intracranial Aneurysm* ; Mass Screening ; Neck ; Parents ; Prospective Studies ; Sensitivity and Specificity ; Subarachnoid Hemorrhage