It has been reported that cavernous hemangiomas in the spine are generally located in vertebral bodies. Wereport a case of epidural cavernous hemangioma, a very rare condition, at the C7-T2 level. MR images showed adumbbell-shaped mass, with iso and high signal intensity on T1- and T2-weighted images, respectively. The mass wasintensely enhanced following Gd-DTPA injection.
Gadolinium DTPA ; Hemangioma, Cavernous* ; Spine

PURPOSE: To describe the MR findings of fibrous dysplasia. SUBJECTS AND METHODS: MR images of fibrousdysplasia in 13 pathologically proved cases were retrospectively analyzed regarding the signal intensity, hypointense rind, internal septations, cortical disruption, soft tissue extension, and the pattern of contrast enhancement. RESULTS: All cases showed low signal intensity on T1-weighted images. On T2-weighted images, 8cases(62%) were hyperintense and 5 cases(38%) hypointense. Hypointense rind was seen in 10 cases(77%), internal septations in 3 cases(23%), and cystic change in 2 cases(15%). Soft tissue extension was observed in fourcases(31%) including one case with pathologic fracture. After Gd-DTPA infusion, central contrast enhancement wasnoted in 8 cases(73%) and peripheral rim enhancement in 3 cases(23%). Pathologically, hypointensity on T2-weighted images was due to numerous bony trabeculae. CONCLUSION: Hypointensity on T1W1 and hyperintensity(62%) or hypointensity(38%) on T2W1 as well as contrast enhancement in fibrous dysplasia depend on degree of cellularity, collagen, cystic and hemorrhagic changes, and bony trabeculae.
Fractures, Spontaneous ; Gadolinium DTPA ; Radiography ; Retrospective Studies

PURPOSE: To evaluate the NMR relaxation properties and imaging characteristics of tissue-specificity for a newly developed macromolecular MR agent. MATERIALS AND METHODS: Phthalocyanine (PC) was chelated with paramagnetic ion, Mn. 2.01g(5.2 mmol) of Phthalocyanine was mixed with 0.37g (1.4 mmol) of Mn chloride at 310 degrees C for 36 hours and then purified by chromatography (CHC13/CH3OH 98/2 v/v, Rf, 0.76) to obtain 1.04g (46%) of MnPC (molecular weight = 2000d), The T1/T2 relaxivity of MnPC was measured in 1.5T(64 MHz) MR using 0.1 mM MnPC. The MR image characteristics of MnPC was evaluated using spin-echo (TR/TE = 500/14 msec) and gradient-echo (FLASH) (TR/TE = 80/4 msec, flip angle = 60) techniques in 1.5T MR scanner. The images of rabbit liver were obtained every 10 minutes up to 4 hours. To study the effect of concentration on image, 20 mM, 50 mM, 100 mM of MnPC were tested. RESULTS: The relaxivities of MnPC at 1.5T (64MHz) were R1 = 7.28 mM-1S-1, R2 = 55.56 mM-1S-1. Compared to the values of Gd-DTPA (R1[= 4.8 mM-1S-1), R2[= 5.2 mM-1S-1]), both T1/T2 relaxivities of MnPC were higher than those of Gd-DTPA. For both of SE and FLASH techniques, the contrast enhancement reached maximum at 10 minutes after bolus injection and the enhancement continued for more than 2 hours. When compared with small molecular weight liver agents such as Gd-EOB-DTPA, Gd-BOPTA and MnDPDP, MnPC was characterized by more prolonged enhancement time. The time course of MR images also revealed biliary excretion of MnPC. CONCLUSION: We developed a new macromolecular MR agent, MnPC. The relaxivities of MnPC were higher than those of small molecular weight Gd-chelate. Hepatic uptake and biliary excretion of MnPC suggests that this agent is a new liver-specific MR agent.
Chromatography ; Gadolinium DTPA ; Liver ; Molecular Weight ; Relaxation

PURPOSE: We wanted to investigate the use of gadolinium based contrast agent (Gd-DTPA) for computed tomography (CT), and we also wanted to assess the effects of valuable injection parameters on enhancement in an experimental rabbit brain model. MATERIALS AND METHODS: In vitro, attenuation measurements of serial dilutions of Gd-DTPA and iopromide were compared. In five rabbits, single level dynamic gadolinium-enhanced brain CT studies were obtained using different injection parameters. A comparison CT scan after iopromide administration was performed. The time-attenuation curves of the brain vessel and parenchyma were obtained and the magnitude of enhancement (Hmax) and the time to peak enhancement (Tmax) were analyzed. RESULTS: In vitro, the attenuation coefficient of undiluted Gd-DTPA (2,578 HU) was higher than that of iopromide (1,761 HU) at equimolar concentrations. In 5 rabbits, the time-attenuation curve demonstrated a distinct pattern with peak enhancement only in the brain vessel, but not in the brain parenchyma. There was increasing linear relationship between the injection rate of Gd-DTPA and Hmax, and a declining linear relationship with Tmax. The higher the concentration of Gd-DTPA, the higher Hmax was, but no significant difference was found for the Tmax. Higher volumes of Gd-DTPA revealed a higher Hmax and a delayed Tmax. CONCLUSION: Enhancement of the brain parenchyma on gadolinium-enhanced CT is minimal, while enhancement of the brain vessels is distinctive. The most important factor affecting Hmax of the vessel is the concentration of the contrast medium and the most important factor affecting Tmax of the vessel is volume of the contrast medium. The gadolinium-based contrast agent may be an reasonable alternative contrast agent for brain CT, and especially in cerebral vessels, and it may also be advantageous for brain parenchyma of those patients with BBB dysfunction.
Brain* ; Gadolinium DTPA ; Gadolinium* ; Humans ; Rabbits ; Tomography, X-Ray Computed

PURPOSE: To assess the value of the bolus-tagging method for improving the image quality of contrast-enhanced MR abdominal angiography, and to evaluate the relationship between peak arterial enhancement time and patients' age, weight and heart rate. MATERIALS AND METHODS: Contrast-enhanced 3D FISP abdominal MR angiography was performed in 81 patients during a four-month period. The bolus-tagging method was used in a study group comprising 33 patients, and to this end, 1 ml of Gd-DTPA (gadolinium-diethylenetriamine penta-acetic acid) was administered. thirty sequential images (1 image/sec) were then obtained using turbo-FLASH sequencing. After determining peak arterial enhancement time from the time-to-signal intensity curve, optimal scan delay time can be calculated according to the formula used in our patient series. The 48 patients in whom the bolus-tagging method was not used comprised the control group ; in the study group scanning commenced at the optimal scan delay time (and at 10 seconds in the control group) after the administration of 0.2 mM/kg Gd-DTPA using an automatic power injector. Using a three-point scale we evaluated and compared between the two groups the success with which arterial images were obtained. In addition, vascular visibility -an indication of the quality of arteries and veins-was determined using a four-point scale. In the study group, the relationship between peak arterial enhancement time and patients' age, weight heart rate was also assessed. RESULTS: Pure arterial images were successfully obtained in 32 patients (97%) in the study group and in 40 (83%) in the control group. This difference was not statistically significant (p>.05). With regard to vascular visibility, diagnostic arterial images were seen in 30 patients (91%) in the study group and in 33 patients (69%) in the control group; arterial visibility was significantly better in the study group (p=.0197). On the other hand, the diagnostic venous images were seen in 31 patients (94%) in the study group and in 36 (75%) in the control group; there was no significant difference between the two groups (p=.2367). Peak arterial enhancement time increased significantly with age (r=.443, p=.0098); no correlation,however was seen between peak arterial enhancement time and weight (p>.05) or heart rate (p>.05). CONCLUSION: Used with contrast-enhanced 3-D FISP MR abdominal angiography, the bolus-tagging method provides better arterial visibility. Peak arterial enhancement time increased significantly with age.
Angiography* ; Arteries ; Gadolinium ; Gadolinium DTPA ; Hand ; Heart Rate ; Humans

PURPOSE: To assess the value of the bolus-tagging method for improving the image quality of contrast-enhanced MR abdominal angiography, and to evaluate the relationship between peak arterial enhancement time and patients' age, weight and heart rate. MATERIALS AND METHODS: Contrast-enhanced 3D FISP abdominal MR angiography was performed in 81 patients during a four-month period. The bolus-tagging method was used in a study group comprising 33 patients, and to this end, 1 ml of Gd-DTPA (gadolinium-diethylenetriamine penta-acetic acid) was administered. thirty sequential images (1 image/sec) were then obtained using turbo-FLASH sequencing. After determining peak arterial enhancement time from the time-to-signal intensity curve, optimal scan delay time can be calculated according to the formula used in our patient series. The 48 patients in whom the bolus-tagging method was not used comprised the control group ; in the study group scanning commenced at the optimal scan delay time (and at 10 seconds in the control group) after the administration of 0.2 mM/kg Gd-DTPA using an automatic power injector. Using a three-point scale we evaluated and compared between the two groups the success with which arterial images were obtained. In addition, vascular visibility -an indication of the quality of arteries and veins-was determined using a four-point scale. In the study group, the relationship between peak arterial enhancement time and patients' age, weight heart rate was also assessed. RESULTS: Pure arterial images were successfully obtained in 32 patients (97%) in the study group and in 40 (83%) in the control group. This difference was not statistically significant (p>.05). With regard to vascular visibility, diagnostic arterial images were seen in 30 patients (91%) in the study group and in 33 patients (69%) in the control group; arterial visibility was significantly better in the study group (p=.0197). On the other hand, the diagnostic venous images were seen in 31 patients (94%) in the study group and in 36 (75%) in the control group; there was no significant difference between the two groups (p=.2367). Peak arterial enhancement time increased significantly with age (r=.443, p=.0098); no correlation,however was seen between peak arterial enhancement time and weight (p>.05) or heart rate (p>.05). CONCLUSION: Used with contrast-enhanced 3-D FISP MR abdominal angiography, the bolus-tagging method provides better arterial visibility. Peak arterial enhancement time increased significantly with age.
Angiography* ; Arteries ; Gadolinium ; Gadolinium DTPA ; Hand ; Heart Rate ; Humans

PURPOSE: The purpose of this study was to analyze the flow signal chracteristics of 3 dimensional time of flight MR angiography (3D TOF MRA) by using a flow phantom model. MATERIALS AND METHODS: Nonpulsatile flow phantom and tap water were used in this experiment. We performed FISP 3D TOF MRA with various values of parameters (repetition time ; 34-100 msec, flip angle ; 10degrees-50degrees, flow velocity ; 14.7-73.6 cm/sec, Gd-DTPA concentration ; 0.6-3.6 mmol/liter). The values of flow signal intensity (SI), signal to noise ratio (SNR) and contrast to noise ratio (CNR) were measured from base images of each MRA. The measured values were displayed graphically and analyzed statistically in relation to various parameters. RESULTS: A prolongation of repetition time resulted in a decrease of CNR of flow. As flip angles increased, SNR and CNR of flow also increased but larger flip angles of more than 40degrees rapidly saturated exit flow. As the flow velocities increased in a range of 14.7-73.6 cm/sec, SNR and CNR of flow decreased. This may be related to the phase dispersion effect of laminar flow, more dominat than the TOF effect. The addition of Gd-DTPA to water increased SNR and CNR of exit flow. There were however, no significant differences of SI, SNR or CNR of flow among the various concentrations of Gd-DTPA. CONCLUSION: An experimental MRA study using a flow phantom model was useful in understanding the flow signal characteristics of 3D TOF MRA within various MRA parameters. Our preliminary results can be used as basic data for refined flow experiments.
Angiography* ; Gadolinium DTPA ; Noise ; Signal-To-Noise Ratio ; Water

PURPOSE: To investigate the usefulness of dynamic MR imaging in the diagnosis of pituitary microadenomas. MATERIALS AND METHODS: Dynamic MR imaging was performed in 31 patients with suspicious pituitary microadenoma. The MR examination was performed on a 2.0T or 1.5T superconductive MR unit using spin echo(SE) technique with arepetition time of 200m sec, echo time of 15 m sec, 128 x 256 matrix and one excitation. Actual sampling time perimage was 26 seconds. The field of view was 25cm and a section thickness of 3mm with 2mm gap was chosen. After arapid hand injection(2-3ml/sec) of Gd-DTPA(0.1 mmol/kg of body weight), dynamic coronal plane MR images were obtained every 20-30 seconds for 3-5 minutes. Between never and ten serial images were usually obtained. After dynamic MR imaging, routine SE T1-weighted images(T1WI) were obtained in the same plane as dynamic images, and detection rates of pituitary microadenoma using dynamic MR imaging and using routine enhanced T1WI, were retrospectively compared. RESULTS: On early dynamic images(30|90 seconds), 23 of 31 adenomas(74.2%) were well visualized, with a clear border ; of particular note is the fact that 11 of the 31 were well visualized at 30-second dynamic image. On late dynamic images(120-180 seconds), six microadeomas(19.4%) were well-visualized and; two(6.5%) were well-visualized throughout on all dynamic images. Meanwhile, 12 of 31 microadenomas(38.7%) were well-visualized on routine Gd-DTPA enhanced T1WI. CONCLUSION: Dynamic MR imaging with Gd-DTPA bolus injection was the most useful technique for the detection of pituitary microadenomas, especially on early-phase dynamic images.
Diagnosis ; Gadolinium DTPA ; Hand ; Humans ; Magnetic Resonance Imaging*

PURPOSE: The purpose of this study is to determine whether MR images after intravenous administration of Gd-DTPA can differentiate exudative and transudative pleural effusion. MATERIALS AND METHODS: We studied 18 patients with ten exudative and eignt transudative pleural effusions diagnosed clinically and by thoracentesis. We analysed the relationship between T1 value(normalized to fat) and the ratio of effusion/serum protein of pleuraleffusion. We also assessed the contrast enhancement of exudative and transudative pleural effusion on T1 weighted SE images taken at 15 and 30 minutes after administration of Gd-DTPA. RESULTS: The relationship between the effusion/serum protein ratio and T1 value(normalized to fat) was statistically not significant(r=0.27, P=0.381).On precontrast spin-echo T1W1, mean signal intensity of the transudate was 0.18 (+/-0.04) and that of the exudatewas 0.24(+/-0.07), values which were not significant differences(P>0.05). Postcontrast mean signal intensities of transudates at 15 and 30 were 0.20+/- 0.06 and 0.26+/-0.08, respectively, values which were not significantly higherthan that of precontrast mean signal intensity(P<0.05). Postcontrast mean signal intensity values of exudative pleural effusions at 15 and 30 mimutes(0.32+/-0.06 and 0.39+/-0.06, respectively) were, on the other hand, significantly higher than that of precontrast mean signal intensity(P<0.05). CONCLUSION: Postcontrast T1-weighted SE images at 15 and 30 minutes can be helpful in the differentiation of transudative and exudative pleural effusion.
Administration, Intravenous ; Exudates and Transudates ; Gadolinium DTPA ; Humans ; Pleural Effusion*

PURPOSE: The water exchange rate between bulk water and bound water is an important parameter in deciding the efficiency of paramagnetic contrast agents. In this study, we evaluated the water exchange rates of various Gd-chelates using oxygen-17 NMR technique. MATERIAL AND MEHTODS: The samples (Gd-DTPA, Gd-DTPA-BMA, Gd-DOTA, Gd-EOB-DTPA) were prepared by mixing 5% (17)O-enriched water (Isotech, USA). The pH of the samples was adjusted to physiological value (pH=7.0) by buffer solution. The variable temperature (17)O-NMR measurements were performed using Bruker-600 (14.1 T, 81.3 MHz) spectrometer. Bruker VT-1000 temperature control units were used to stabilize the temperature. The (17)O spin-spin relaxation times (T2) were measured using Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence with 24 echo trains. The variable temperature T2 relaxation data were then fitted into Solomon-Bloembergen equations using least square fit algorithm to estimate the water exchange times. RESULTS: From the measured (17)O-NMR relaxation rates, the determined water exchange rates at 300K are : 0.42 microsecond for Gd-DTPA, 1.99 microsecond for Gd-DTPA-BMA, 0.27 microsecond for Gd-DOTA, and 0.11 microsecond for Gd-EOB-DTPA. The Gd-DTPA-BMA showed slowest exchange whereas Gd-EOB-DTPA had fastest water exchange rate. In addition, it was found that the water exchange rates of all samples had exponential temperature dependence with different decay constant. CONCLUSION: (17)O-NMR relaxation rate measurements, when combined with variable temperature technique, provide a solid tool for studying water exchange rate, which is very important in investigating the detailed mechanism of relaxation enhancement effect of the paramagnetic contrast agents.
Contrast Media* ; Gadolinium DTPA ; Hydrogen-Ion Concentration ; Relaxation