PURPOSE: The purpose of this study was to evaluate the effects of magnetization transfer contrast(MTC) andfat-suppression(FS) in variable spin-echo and gradient-echo sequences for articular cartilage imaging and todetermine the optimal pulse sequences. MATERIALS AND METHODS: Using variable 7-pulse sequences, the knees of 15pigs were imaged Axial images were obtained using proton density and T2-weighted spin-echo (PDWSE and T2WSE),turbo spin-echo (TSE), multiplanar gradient-echo (MPGR), and 3D steady-state gradient-echo (3DGRE) sequences, andthe same pulse sequences were then repeated using MTC. Also T1-weighted spin-echo(T1WSE) and 3D spoiledgradient-echo(3DSPGR) images of knees were also acquired, and the procedure was repeated using FS. For each knee,a total of 14 axial images were acquired, and using a 6-band scoring system, the visibility of and thevisibilities of the the articular cartilage was analyzed. The visual effect of MTC and FS was scored using a4-band scale. For each image, the signal intensities of articular cartilage, subchondral bone, muscles, and salinewere measured, and signal-to-noise ratios(SNR) and contrast-to-noise ratios(CNR) were also calculated. RESULTS: Visibility of the cartilage was best when 3DSPGR and T1WSE sequences were used. MTC imaging increased the negativecontrast between cartilage and saline, but FS imaging provided more positive contrast. CNR between cartilage andsaline was highest when using TSE with FS(-3 5 1 . 1 +/-15.3), though CNR between cartilage and bone then fell to-1 4 . 7 +/-10.8. In MTC imaging using MPGR showed the greatest increase of negative contrast between cartilage andsaline(CNR change=-74.7); the next highest was when 3DGRE was used(CNR change=-34.3). CNR between cartilage andbone was highest with MPGR(161.9 +/-17.7), but with MTC, the greatest CNR decrease(-81.8) was observed. Thegreatest CNR increase between cartilage and bone was noted in T1WSE with FS. In all scans, FS provided acartilage-only positive contrast image, though the absolute value of CNR was lower than that of MTC imaging. CONCLUSION: The most prominent effects of MTC and FS were seen in MPGR and T1WSE, respectively, though forcartilage, optimal high signal intensity and contrast can be achieved using 3DGRE with MTC, and 3DSPGR with FS.
Cartilage ; Cartilage, Articular* ; Knee ; Magnetic Resonance Imaging* ; Muscles ; Protons

No abstract available.
Duodenal Obstruction*

PURPOSE: To assess the effect of lordotic curve change of the cervical spine on disk bulging and spinal stenosis by means of functional cervical MR imaging at the flexion and extension position. MATERIALS AND METHODS: Using a 1.5T imager, kinematic MR examinations of 25 patients with degenerative spondylosis (average age, 41 years) were performed at the neutral, flexed and extended position of the cervical spine. Sagittal T2-weighted turbo spin-echo images were obtained during each of the three phases. Lordotic an-gle, bulging thickness of the disk, AP diameter of the spinal canal, and distance between the disk and spinal cord were measured on the workstation at each disk level. After qualitative independent observation of disk bulging, one of four grades(0, normal; 1, mild; 2, moderate; 3, marked) was assigned at each phase, and after further comparative observation, one of five scores (-2, prominent decrease; -1, mild decrease; 0, no change; 1, notable increase; 2 prominent increase) was also assigned. In addition, bulging thickness of the disk was measured and compared at the neutral, flexed, and extended positions. RESULTS: Average angles of the cervical spine were 160.5+/-5.9 degrees (neutral position, lordotic angle); 185.4+/-8.5 degrees (flexion, kyphotic angle); and 143.7+/-6.7 degrees (extension, lordotic angle). Average grades of disk bulging were 0.55 at the neutral position, 0.16 at flexion, and 0.7 at extension. Comparative observation showed that average scores of disk bulging were -0.39 at flexion and 0.31 at extension. The bulging thickness of the disk decreased by 24.2% at flexion and increased by 30.3% at extension, while the diameter of the spinal canal increased by 4.5% at flexion and decreased by 3.6% at extension. The distance from the posterior margin of the disk to the anterior margin of the spinal cord decreased at both flexion(6.6%) and extension(19.1%). CONCLUSION: Functional MRI showed that compared with the neutral position, disk bulging and spinal stenosis are less prominent at flexion and accentuated at extension. The results demonstrate the need to consider the extent to which changes in the cervical lordotic curve affect the degree of disk bulging and spinal stenosis.
Animals ; Humans ; Lordosis* ; Magnetic Resonance Imaging* ; Spinal Canal ; Spinal Cord ; Spinal Stenosis* ; Spine ; Spondylosis

PURPOSE: To evaluate the MR findings of brain damage in cerebral palised patients and to correlate it with gestational age and the time of damage. MATERIALS AND METHOD: A retrospective analysis was performed in 40 patients who underwent MR scanning for evaluation of brain lesion in clinically diagnosed cerebral palsy. Authors classified the patients into two groups as premature and full-term and compared MR findings of the two groups. RESULTS: Abnormal MR findings were noted in 28 cases (70%). Five out of 6 patients who had been born prematurely showed isolate periventricular white matter lesions. Twenty-three out of 34 patients who had been born at full-term showed abnormal MR findings. Of these 23 patients, migration anomalies in 7 patients, isolate periventricular white matter lesions in 3 patients, and other combined periventricular subcortical white matter and deep gray matter lesions in 14 patients were seen. At least, 10 patients(43%) of full term group showed abnormal MRI findings reflecting intrauterine brain damage and all 5 patients of premature group showed isolate periventricular white matter lesions suggesting immaturity of brain. CONCLUSION: MRI is thought to be very useful in the assessment of brain damage for the patients with cerebral palsy by recognizing the location of the lesion and estimating the time of damage.
Brain ; Cerebral Palsy* ; Gestational Age ; Humans ; Magnetic Resonance Imaging ; Retrospective Studies

PURPOSE: To correlate MR findings with histologic findings in avascular necrosis(AVN) of the femoral head. MATERIALS AND METHODS: MR imaging was performed with 8 femoral head specimens using T1- and proton density weighted coronal SE sequences, and compared with contact radiography and histologic sections. RESULTS: In each specimen, necrotic zone in the superior portion of femoral head, repair zone located inferior to the necrotic zone, and rim adjacent to normal bone marrow could be defined. Necrotic zone showed high signal intensity on both T1- and proton density- weighted images in 3 cases which were composed of necrotic bone and marrow, and low signal intensity on both sequences in 2 cases which were composed of necrotic bone marrow with amorphous cellular debris. Mixed high and low signal intensities were seen in 3 cases. The repair zone showed low signal intensity on Tl-weighted image and high signal intenisty on proton density weighted image in 5 cases which were composed of thickened trabecular bone and meSenchymal tissue and also showed intermediate signal intensity on T1 weighted image and high signal intensity on proton density weighted image in 3 cases which were composed of osteoid, chondroid and undifferentiated mesenchymal cells. Rim shown as the low signal intensity on T1 weighted image in all cases was corresponded to viable thickened trabecular bone. CONCLUSION: MR imaging would be the best modality in the diagnosis of avascular necrosis of fernoral head and when used in conjuction with degree and location of signal intensity, the prediction of histologic finding may be possible.
Bone Marrow ; Diagnosis ; Head* ; Magnetic Resonance Imaging* ; Necrosis* ; Protons ; Radiography

OBJECTIVE: To investigate the frequency of autonomic nervous dysfunction and assess the factors associated with autonomic nervous dysfunction in patients with rheumatoid arthritis (RA). METHODS: Three battery of cardiovascular autonomic nervous function tests (CAN test);heart rate response to Valsalva maneuver,deep breathing and standing up,were performed in 68 patients who met the 1987 American Rheumatism Association revised criteria for RA and 58 healthy controls.Autonomic nervous dysfunction was defined as 2 of 3 CAN tests were abnormal. Clinical and radiographic variables such as age,sex,disease duration,erythrocyte sedimentaton rate (ESR)and bone destruction,were analyzed in patients with or without autonomic nervous dysfunction. RESULTS: In patients with RA,the frequency of autonomic nervous dysfunction was higher than healthy controls (50.8%in RA vs 15.5%in healthy controls,p<0.05).Age,sex,disease duration,ESR and bone destruction were not associated with autonomic nervous dysfunction in patients with RA CONCLUSIONS: This results suggest that autonomic nervous dysfunction may be a significant feature in patients with RA.
Arthritis, Rheumatoid* ; Humans ; Respiration ; Rheumatic Diseases

M-mode echocardiograms were recorded in 268 apparently healthy young male adults and the mitral valve motion during systole was analyzed. In 149 cases( 55.6%) out of 268 the predominant echo of mitral valve closure(CD line) was recorded as smooth line moving slowly anteriorly, in 48 cases(17.9%) the CD line showed an abrupt transient posterior motion during early systole, in 24 cases(9.0%) there were multiple additional echoes posterior to the CD line, 17 cases(6.3%) the mitral valve closure was recorded as pansystolic anteriorly concave echo deviating less than 2 mm from a drawn CD line, and 10 cases(3.7%) as curvilinear and anteriorly convex echo deviating from a drawn CD line. In the remaining 20 cases(7.5%), the mitral valve closure was recorded as pansystolic anteriorly concave echo deviating more than 2 mm from a drawn CD line, which was categorized to have mitral valve prolapse in the current study. However, there were no significant differneces in various echocardiographic dimensions of the heart and the aorta between those with and without mitral valve prolapse.
Adult ; Aorta ; Echocardiography* ; Heart ; Humans ; Male* ; Mitral Valve Prolapse* ; Mitral Valve* ; Systole

PURPOSE: The thickening of the gallbladder wall is a valuable finding for the diagnosis of cholecystitis, butmay be seen in non-cholecystic disease as well as in acute or chronic cholecystitis. The purpose of this study isto determine the value of color Doppler sonography in differentiating the causes of thickened gallbladder wall. MATERIALS AND METHODS: Ninety eight patients with thickened gallbladder wall(more than 3mm) which was not due to gallbladder cancer were prospectively evaluated with color Doppler sonography. Sixty-six cases, confirmed bypathologic reports and clinical records, were analyzed for correlation between thickened gallbladder wall andcolor flow signal according to the underlying causes. RESULTS: Of the 66 patients, 28 cases were cholecystitisand 38 cases had non-cholecystic causes such as liver cirrhosis, ascites, hepatitis, pancreatitis, renal failure,and hypoalbuminemia. Of the 28 patients with cholecystitis(12 acute, 16 chronic), 23(82%) had color Doppler flowsignals in the thickened gallbladder wall. Of the 38 patients with non-cholecystic causes, eight(21%) had color Doppler flow signals. There was a statistically significant difference of color Doppler flow signals between the cholecystitis and non-cholecystic groups(p=0.0001). No significant difference of color Doppler flow signals was found between cases of acute and chronic cholecystitis. Of the 23 patients with color Doppler flow signals in 28cases of cholecystitis, 18(78.3%) showed a linear pattern and five(21.7%) showed a spotty pattern. Of the eight patients with color Doppler flow signals in the 38 non-cholecystic cases, four(50%) showed a linear pattern andfour(50%) showed a spotty pattern. In cholecystitis, a linear color Doppler flow signal pattern is a much more frequent finding than a spotty pattern. CONCLUSION: Color Doppler sonography is a useful and adequate method for determining whether a thickened gallbladder wall is the result of cholecystitis or has non-cholecystic causes.
Ascites ; Cholecystitis ; Diagnosis ; Gallbladder* ; Hepatitis ; Humans ; Hypoalbuminemia ; Liver Cirrhosis ; Pancreatitis ; Prospective Studies

Objectives: The purpose of this study was to investigate the possibility of preventing dental erosion caused by fermented milk in early carious teeth by applying 0.2% sodium fluoride to the tooth surface and adding 0.5% calcium to the drink. Methods: We selected the experimental drink Yakult, which is the best-selling domestic fermented milk drink. A total of five groups were selected as experimental groups (mineral water, fermented milk, 0.2% NaF+fermented milk, 0.2% NaF+(fermented milk+0.5% Ca), and 0.2% NaF+Distilled water groups). After forming the artificial early caries, the pH cycling was administered for five days to derive surface microhardness and scanning electron microscope (SEM) image results. Results: When comparing the surface microhardness before and after treatment in each group, significant differences were found among the four groups (P<0.05), except in the fermented milk group (P>0.05). A comparison of the difference in surface microhardness before and after pH cycling among the groups revealed a significant difference (P<0.05). There was no significant difference between the 0.2% NaF+(fermented milk+0.5% Ca) group, 0.2% NaF+distilled water group, and the mineral water group (P>0.05). The 0.2% NaF+fermented milk and fermented milk groups showed significant differences from the other groups (P<0.05). In the SEM image, 0.2% NaF+(fermented milk+0.5% Ca), 0.2% NaF+distilled water, and mineral water groups (P>0.05) showed smoother surfaces than the 0.2% NaF+fermented milk and fermented milk groups. Conclusions Based on these results, it was confirmed that if 0.5% calcium was included in the fermented milk along with the fluoride mouth rinsing program in schools using 0.2% fluoride every week when drinking fermented milk, it is possible to effectively prevent dental erosion even in early carious teeth.

PURPOSE: Spirometric gating quantitative CT, PULMO-CT, is an objective method for the measurement of pulmonary parenchymal attenuation at a constant level of inspiration. In order to obtain a normal value for quantitative CT of the lung, the authors therefore used PULMO-CT to evalvate the lung density of healthy koreans with different respiratiory status. MATERIALS AND METHODS: Twenty healthy Korean volunteers, 18 men and 2 women, ranging in age from 24 to 27 years and with normal chest radiography, were evaluated using the PULMO-CT option of Somatom Plus(Siemens, Erlangen, Germany). Spirometric gating HRCT images, at levels of 50% and 20% of vital capacity, were obtained at the level of the tracheal carina and at 5cm above and below this point. The images were analyzed by semiautomatic programs and the results were evaluated using the Student t-test. RESULTS: The mean attenuation value of lung parenchyma at 50% of vital capacity was -791HU27.1 and at 20% was -700HU+/-42.9. The difference in lung attenuation was 91HU and was statistically significant(p<0.001). The for 58% of participants, the highest reading for of lung attenuation at 50% of vital capacity was between -899HU and -800HU, and for 20.3% of participants, this reading was between -799HU and -700HU. At 20% of vital capacity, the largest proportion of participants(43.8%) had a reading of between -799HU and -700HU; the reading of 35.2% was higher than -699HU. CONCLUSION: Respiratory status significantly affects the quantitative accessment of pulmonary parenchyma; in order to determine, during quantitative HRCT, the parameters of a pathologic condition, lung parenchyma of differing respiratory status must be evaluated.
Female ; Humans ; Lung* ; Male ; Radiography ; Reference Values ; Thorax ; Vital Capacity ; Volunteers