PURPOSE: To assess the signal enhancement by gadolinium-DTPA-polylysine (Gd-polylysine) as compared to gadopentetate (Gd-DTPA) in MR imaging of heart that have undergone ischemia-reperfusion, and to estimate the extent of myocardial damage covered bythe MR signal enhancement. MATERIALS AND METHODS: A series of contrast enhanced cardiac MR images were obtained from 17 cats subjected to a 90 minutes of occlusion of the left anterior descending coronary artery (LAD) followed by a 90 minutes of raperfusion. Time courses of changes in the signal intensity (Sl) of the ischemic area were measu red in Gd-polylysine group (8 cats) and Gd- DTPA group (9 cats). The size of U R signal enhanced area was then compared to the sizes of infarction and the area at risk revealed byTTC histochemical staining. RESULTS: Maximum Sis were obtained at 60 minutes and 30 minutes after injection of the contrast material, respectively for Gd-polylysine group and Gd-DTPA group. Signal enhancement was stronger and persistent for a longer period in Gd-polylysine group than in GD-DTPA group. Sizes of the enhanced area, the infarction, and the area at risk were about 30%, 15%, and 50% of the total left ventricle (LV) area; the difference between the groups was statistically insignificant. CONCLUSION: Gd-polylysine can be used better for a blood pool marker than Gd-DTPA in MR imaging of myocardial ischemia, due to its strong and persistent signal enhancement. The MR signal enhanced area includes both the infarcted area and a portion of the area at risk.
Animals ; Cats* ; Coronary Vessels ; Gadolinium DTPA ; Gadolinium* ; Heart ; Heart Ventricles ; Infarction ; Magnetic Resonance Imaging* ; Myocardial Ischemia ; Pentetic Acid ; Polylysine*

PURPOSE: In this study, the medication effects of Milnacipran and Pregabalin, as well known as fibromyalgia treatment medicine, in fibromyalgia syndrome patients were compared through the change of BOLD signal in pain related functional MRI. MATERIALS AND METHODS: Twenty fibromyalgia syndrome patients were enrolled in this study and they were separated into two groups according to the treatment medicine: 10 Milnacipran (MLN) treatment group and 7 Pregabalin (PGB) treatment group. For accurate diagnosis, all patients underwent several clinical tests. Pre-treated and post-treated fMRI image with block-designed pressure-pain stimulation for each group were obtained to conduct the statistical analysis of paired t-test and two sample t-test. All statistical significant level was less than 0.05. RESULTS: In clinical tests, the clinical scores of the two groups were not significantly different at pre-treatment stage. But, PGB treatment group had lower Widespread Pain Index (WPI) and Brief Fatigue Inventory (BFI) score than those of MLN treatment group at post-treatment stage. In functional image analysis, BOLD signal of PGB treatment group was higher BOLD signal at several regions including anterior cingulate and insula than MLN treatment group at post-treatment stage. Also, paired t-test values of the BOLD signal in MLN group decreased in several regions including insula and thalamus as known as 'pain network'. In contrast, size and number of regions in which the BOLD signal decreased in PGB treatment group were smaller than those of MLN treatment group. CONCLUSION: This study showed that MLN group and PGB group have different medication effects. It is not surprising that MLN and PGB have not the same therapeutic effects since these two drugs have different medicinal mechanisms such as antidepressants and anti-seizure medication, respectively, and different detailed target of fibromyalgia syndrome treatment. Therefore, it is difficult to say which medicine will work better in this study.
Antidepressive Agents ; Diagnosis ; Fatigue ; Fibromyalgia* ; Follow-Up Studies* ; Humans ; Magnetic Resonance Imaging* ; Prostaglandins B ; Thalamus ; Pregabalin

In vivo 31P NMR spectroscopic study of forearm wrist flexor muscles was performed in two groups of volunteers composed respectively of 6 sedentaries and 6 canoe athletes. A continuous isometric contraction of endurance exercises was adopted in oder to assess the endurance capacity and recovery potential of skeletal muscles. Differences in high energy phosphorus metabolism between the sedentaries and athletes were evaluated with and emphasis on the intracellular pH and Pi/PCr ratio as indicators of high energy phosphorus metabolism. There were no differences of baseline pH and Pi/PCr ratio between the two groups. The athletes sustained the exercise at more acidic intracellular pH and at a higher Pi/PCr ratio of intracellular conditions for an all-out than did the sedentaries. The recovery rate of pH showed no difference between the two groups. There was a tendency of faster recovery of Pi/PCr in athletes showing half recovery time(T1/2) of 39.0±3.0 seconds as compared to that of sedentaries (55.7±7.5 seconds). The recovery rate of Pi/PCr as a function of Pi/PCr ratio at a given period of time was significantly faster in athletes than in sedentaries (P<0.001). The correlation coefficient of the recovery rate of Pi/PCr against the Pi/PCr ratio was 0.985 and 0.914 respectively for the athletes and sedentaries. The pH and the Pi/PCR ratio at an all-out state can be used as indicators of endurance capacity and the recovery rate of Pi/PCr, as a reovery potential of skeletal muscles.
Athletes* ; Exercise ; Forearm ; Humans ; Hydrogen-Ion Concentration ; In Vitro Techniques* ; Isometric Contraction ; Metabolism ; Muscle, Skeletal* ; Muscles ; Phosphorus ; Volunteers ; Wrist

BACKGROUND: To evaluate the metabolic and pathological changes associated with myocardial ischemia-reperfusion, magnetic resonance spectroscopy with 31P was applied as well as pathological examination. METHODS: Effect of adenosine on the recovery of high energy phosphorous metabolites during the reperfusion period following 90 minutes of left anterior descending coronary artery(LAD) ligation was assessed by 31P spectroscopy in 13 cats(8 : control group, 5 : adenosine group). In adenosine group 0.2 mg/kg/min of adenosine was infused intravenously for 90 minutes from 30 minutes before reperfusion. The experiments were peformed on a 4.7 T/30cm Biospec MRS/MRI system(Bruker, Switzerland) and the MR signals were obtained by using innerdiameter 1.5 cm sized doubly tuned surface coil. The size of the spectral peaks was measured by area integration method. RESULTS: In control group, high energy phosphorous metabolites decreased continueously during the ischemic period revealing the lowest values at the end of the periods : 17.0% for PCr and 24.0% for ATP, PCr depleted below 50% of the baseline level immediately after the LAD ligation and ATP, after 15 minutes of ischemia. Therfore the depletion rate was faster in PCr change than in ATP. The recovery of the PCr and ATP occurred after reestablishment of blood flow showing, for example, 43.3% and 36.3% of the baseline levels after 10 minutes of reperfusion. After infusion of adenosine, there was a tendency of higher recovery rates of high energy phosphates than in control group. Recovery rates of PCr and ATP after 90 minutes of reperfusion, were 28.2%, 11.2% in control group and 38.3%, 18.6% in adnosine group, respectively. In adenosine grop, relative sizes of infarction were not statistically different from those of control group. CONCLUSIONS: 31P MRS can be used for in-vivo assessment of the changes of high energy phosphorous metablites concerning acute myocardial ischemia and reperfusion. Adenosine infusion improves the recovery of ATP and PCr during the reperfusion period following acute ischemia.
Adenosine Triphosphate ; Adenosine* ; Animals ; Cats* ; Infarction ; Ischemia ; Ligation ; Magnetic Resonance Spectroscopy ; Myocardial Ischemia ; Phosphates ; Polymerase Chain Reaction ; Reperfusion ; Spectrum Analysis

This study was performed to assess the accuracy of 31P magnetic resonance spectroscopy(MRS) in the evaluation of myocardial ischemia in cats. Twelve cats underwent myocardial ischemia and reperfusion induced by 90 minutes ligation followed by 90 minutes recirculation of the left anterior descending coronary artery (LAD). MRS was performed using a 4.7T Biospec MRS/MRI system (Bruker, Switzerland). An inner diameter 1.5cm-sized doubly tuned surface coli was used for the collection of the MR signal. The coli was implanted to the epicardial surface at the expected area of infarction. 31P MRS was acquired before and during the periods of ischemia and reperfusion with 5-minute to 30-minute of intervals. After completion of the 31P MRS study, animals were sacrificed and the hearts were excised for 2,3,5-triphenyl tetrazolium chloride (TTG0 histochemical staining. The area of infarct was measured on the photographs of TTG stained heart slices using a computer programmed planimetry and the results were compared with those of the 31P MRS study. The level of phosphocreatine (PCr) was decreased to 28.2±6.9% of the baseline level 90 minutes after occlusion and recovered to 43.8±4.8% of the baseline level at the end of the reperfusion. A 50% depletion of PCr was reached 5 minutes after the LAD occlusion. The ATP was decreased to a 26.6±3.6% of the baseline level 90 minutes after occlusion and recovered to a 35.9±6.0 of the baseline level 90 minutes after reperfusion. The decreasing rate of ATP was slower than that of PCr showing a 50% of depletion 15 minutes after occlusion. The PCr/ATP ratio was 1.16±0.09 at the baseline, decreased to 0.88±0.07 at 30 minutes of occlusion, and then progressively increased during the late ischemic and reperfused periods. The ratio of the infarcted area to the effective signal area of the surface coli was inversely correlated to the ATP (r=0.68) and PCr (r=0.40) levels obtained at the end of reperfusion. In conclusion, 31P MRS reflects the changes in myocardial high energy phosphorous metabolism during the actue ischemia and reperfusion. If on adequate localization technique is feasible, 31P MRS can be used clinically in the diagnosis and monitoring of the patients with acute myocardial infarction.
Adenosine Triphosphate ; Animals ; Cats* ; Coronary Vessels ; Diagnosis ; Heart ; Humans ; Infarction ; Ischemia ; Ligation ; Metabolism ; Myocardial Infarction* ; Myocardial Ischemia ; Phosphocreatine ; Polymerase Chain Reaction ; Reperfusion ; Spectrum Analysis*

BACKGROUND: Reestabilshment of blood flow is a standard therapeutic modality to salvage the myocardium at risk in an acute phase of myocardial infarction. However, there are significant evidences that reperfusion per se may injure the potentially viable myocardium, and a number of pharmacological agents were tried to reduce this reperfusion injury. Adenosine, an endogenous vasodilator, is suggested to reduce repergusion inury. To evaluate the myocardial protective effect of adenosine, magnetic resonance spectroscopy with superscript P was applied to feline model of acute myocardial ischemia-reperfusion, as well as pathological examination. METHODS: Effects of adenosine on the recovery of high energy phosphorous metabolites during 90 minutes of reperfusion period following 90 minutes of left anterior descending coronary artery ligation were assessed by31P spectroscopy in 27 cats(10: control group, 8: adenosine I group, 9: adenosine II group). In adenosine groups 0.2 mg/kg/min of adenosine was infused intravenously for 90 minutes from 30 miniutes before reperfusion in group I, and from just before reperfusion in group II. The experiments were performed on a 4.7 T/30 cm Biospec MRS/MRI system and the MR signals were obtained by using inner-diameter 1.5 cm-sized doubly tuned surface coil. The size of the spectral peaks was measured by area integration method. RESULTS: 1) Phosphocreatine(PCr) decreased rapidly with progression of ischemia, and recovered in reperfusion period in each group. PCr values in the reperfusion period were significantly higher in adenosine group than those in control group, although there was no difference between adenosine group I and II. 2) ATP decreased with progression of ischemia, and recovered in reperfusion period in each group. ATP values in the reperfusion period were significantly higher in adenosine groups than those in control group, byt there was no difference between adenosine group I and II. 3) pH decreased uniformly with progression of ischemia and recovered in reperfusion period, showing no difference between control and adenosine groups. 4) PCr/ATP ratio, representing the potential of oxidative phosphorylation, dereased with progression of ischemia and increased in reperfusion period. PCr/ATP ratio showed no difference between control, adenosine I and II groups. 5) Risk area/left ventricle ratio was not different in control and adenosine groups. Infarct size/risk area and infarct size/left ventricle ratios were smaller in adenosine II than those in control group. Howerver no significant diffence was noticed between adenosine I and control, and between adenosine I and II group. CONCLUSION: Intravenous infusion of adenosine showed the tendency of reducing the infarct size in the feline model of acute myocardial ischemia-reperfusion, and adenosine could improve significantly the recovery of high energy phosphate metabolites. This myocardial pretective effect of adenosine is considered to be present mainly in the reperfusion period.
Adenosine Triphosphate ; Adenosine* ; Coronary Vessels ; Hydrogen-Ion Concentration ; Infusions, Intravenous ; Ischemia ; Ligation ; Magnetic Resonance Spectroscopy ; Myocardial Infarction ; Myocardial Ischemia ; Myocardium ; Oxidative Phosphorylation ; Polymerase Chain Reaction ; Reperfusion ; Reperfusion Injury ; Spectrum Analysis

OBJECTIVE: This study proposes an automated diagnostic method to classify patients with Alzheimer's disease (AD) of degenerative etiology using magnetic resonance imaging (MRI) markers. METHODS: Twenty-seven patients with subjective memory impairment (SMI), 18 patients with mild cognitive impairment (MCI), and 27 patients with AD participated. MRI protocols included three dimensional brain structural imaging and diffusion tensor imaging to assess the cortical thickness, subcortical volume and white matter integrity. Recursive feature elimination based on support vector machine (SVM) was conducted to determine the most relevant features for classifying abnormal regions and imaging parameters, and then a factor analysis for the top-ranked factors was performed. Subjects were classified using nonlinear SVM. RESULTS: Medial temporal regions in AD patients were dominantly detected with cortical thinning and volume atrophy compared with SMI and MCI patients. Damage to white matter integrity was also accredited with decreased fractional anisotropy and increased mean diffusivity (MD) across the three groups. The microscopic damage in the subcortical gray matter was reflected in increased MD. Classification accuracy between pairs of groups (SMI vs. MCI, MCI vs. AD, SMI vs. AD) and among all three groups were 84.4% (+/-13.8), 86.9% (+/-10.5), 96.3% (+/-4.6), and 70.5% (+/-11.5), respectively. CONCLUSION: This proposed method may be a potential tool to diagnose AD pathology with the current clinical criteria.
Alzheimer Disease* ; Anisotropy ; Atrophy ; Brain ; Classification* ; Diagnosis ; Diffusion Tensor Imaging ; Humans ; Magnetic Resonance Imaging ; Memory ; Mild Cognitive Impairment ; Pathology ; Support Vector Machine

PURPOSE: The aim of this study was to examine the volume differences of human brain 3-D MR images obtained by automatic segmentation methods depending on brain templates and image acquisition conditions, respectively. MATERIALS AND METHODS: 3D T1-weighted MR images oriented in coronal and sagittal plane were acquired from eight healthy subjects (29.5+/-5.66 years) using two identical 3T MR scanners at different sites. Caucasian brain template and Korean elderly brain template were applied for the same subject to segment brain structural region. Volumetric differences and variation of gray matter, white matter and hippocampus depending on scan orientations and brain template types were statistically evaluated. RESULTS: Volumetric measurements have some different results for the same subject images depending on scan orientation in identical MR scanners but not significantly. However, all segmented volumes relied upon brain templates were significantly different (p<0.05). Small variation of the volume in gray matter, white matter (coefficient of variation, CV< or =1%) and hippocampus (CV< or =3%) were obtained. Comparing the mean CV in all segmented regions, variation of scan orientation was not significantly different with inter scanner variation but variation relied upon brain templates were significantly different (p<0.001). CONCLUSION: Authors found that brain template regarding the specific properties of the subjects is required to reduce the errors of brain volumetry.
Aged ; Brain ; Hippocampus ; Humans ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; Magnetics ; Magnets ; Orientation

Using KAIS 0.15 Telsla resistive magnetic imaging system, ECG gated magnetic resonance (MR) image of variouscardiovascular disease was obtained in 10 patients. The findings of MR image of the cardiovascular disesase wereanlaysed and the results were as follows: 1. In 6 cases of acquired and congenital cardiac disease, there were 2cases of myocardial infarction, 1 case of mitral stenosis and 3 cases of corrected transpossition of greatvessels. The others were 3 cases of aortic disease and 1 case of pericardial effusion with lymphoma. 2. Myocardialthinning left ventricular aneurysm were detected in MR images of myocardial infarction. The left atrium was welldelineated and enlarged in the case of mitral stenosis. And segmental analysis was possible in the cases ofcorrected transposition since all cardiac structures were well delineated anatomically. 3. In aortic disease, thefindings of MR image were enlarged lumen, compressed cardic chambers in ascending aortic aneurysm, intimal flap,enhanced false lumen in dissecting aneurysm and irregular narrowing of aorta with arterial obstruction inTakayasu's arteritis. 4. Pericardial effusion revealed a conspicuous contrast with neighboring meidastinal fat andcardiac wall due to it low signal encircling cardiac wall. 5. ECG gated MR image is an accurate non-invasive imaging modality for the diagnosis of cardiovascular disease and better results of its clinical application areexpected in the futher development in the imaging system and more clinical experiences.
Aneurysm ; Aneurysm, Dissecting ; Aorta ; Aortic Aneurysm ; Aortic Diseases ; Arteritis ; Cardiovascular Diseases ; Diagnosis ; Electrocardiography ; Heart Atria ; Heart Diseases ; Humans ; Lymphoma ; Magnetic Resonance Imaging ; Mitral Valve Stenosis ; Myocardial Infarction ; Pericardial Effusion

PURPOSE: The aim of this study was to evaluate the variations of brain volumetry between the different MR scanners or the different institutes. MATERIALS AND METHODS: Ten normal subjects were scanned at four different MR scanners, two of them were the same models, to measure inter-MR scanner variations using intraclass correlation coefficient (ICC), coefficient of variation (CV) and percent volume difference (PVD) and to calculate minimal thresholds to detect the significant volumetric changes in gray matter and subcortical regions. RESULTS: Averaged statistical reliability (ICC = 0.837) and volumetric variation (CV = 4.310%) in all segmented regions were observed on overall MR scanners. Comparing the segmented volumes with PVD between two MR scanners, volumetric differences on same models were the lowest (PVD = 3.611%) and volume thresholds were calculated with 7.168%. PVD results and thresholds values on systemically different MR scanners were evaluated with 5.785% and 11.340% respectively. CONCLUSION: Authors conclude that the reliability of brain volumetry is not so high. Calibration studies of MRI system and image processing are essential to reduce the volumetric variability. Additionally, frameworks comprised of database and algorithms with high-speed image processing are also required for the efficient image data management.
Brain ; Calibration