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 compare the sensitivity and staging accuracy of dynamically enhanced MR imaging(hereafter, DEI)and turbo spin-echo(TSE) T2-weighted imaging(hereafter, T2WI) in cases of cervical carcinoma. MATERIALS AND METHODS: MR images(T2WI and DEI) of 25 cervical carcinoma patients, diagnosed during surgery, were reviewed by tworadiologists. T2WI employed the TSE technique; dynamic MR imaging, the FLASH technique in the axial plane. DEimages were obtained immediately and at 30, 60, 120, and 180 seconds after rapid injection of Gd-DTPA. The degreeof visualization of the tumor, and its invasiveness, were graded as good, fair, or poor. By correlating thehistopathologic results, the accuracy of the two MR imaging techniques was compared. RESULTS: For tumorvisualization, T2WI was good in 13/25 cases (52%), fair in 3/25(12%), and poor in 9/25(36%); DEI was good in5/25(20%), fair in 7/25(28%), and poor in 13/25 cases (52%). CONCLUSION: For the detection and staging of cervicalcarcinoma, T2WI is superior to DEI. For the diagnosis and staging of cervical carcinoma, DEI is thereforeunnecessary.
Diagnosis* ; Gadolinium DTPA ; Humans ; Magnetic Resonance Imaging* ; Uterine Cervical Neoplasms*

PURPOSE: To evaluate the diagnostic value of magnetic resonance(MR) imaging in the differentiation of benign and malignant soft tissue masses. MATERIALS AND METHODS: MR examination of 47 patients with pathologically proven soft tissue masses were reviewed. This series included 19 malignant and 28 benign masses of upper and lower extremities, body, and neck. Lesions were evaluated for their margin, signal intensity and homogeneity, pattern and degree of enhancement, involvement of the adjacent tissue, and degree of surrounding edema. RESULTS: Sixteen of benign lesions(57.1%) had well-defined and smooth margin. The tumor margin was irregular in nine lesions(47.4%), however, smooth margin was noted in five cases(26.3%) of malignant lesions. On T2-weighted images, signal inhomogeneity was noted in 84% of malignant lesions and 32% of benign lesions. On Gd-DTPA enhancement study, all malignant lesions(n=18) showed enhancement and 89% showed heterogeneously enhancing pattern. Neurovascular involvement was observed more often in malignancy(n=7) compared to benign lesion(n=1). Direct invasion of the adjacent bone was noted only in malignant lesions(n=3). Surrounding edema was revealed in two benign and 11 malignant lesions. CONCLUSION: MR imaging appears useful for differentiating malignant and benign lesions by identifying tumor margin, signal homogeneity of tumor, pattern and degree of enhancement, involvement of adjacent tissue, and surrounding edema. The nature of the lesion can be determined in the majority of cases although no unique criterion to differentiate benignancy and malignancy is identified.
Edema ; Gadolinium DTPA ; Humans ; Lower Extremity ; Magnetic Resonance Imaging* ; Neck

PURPOSE: To determine the electronic spin relaxation times, T1e, of three commercially available Gd-chelated MR contrast agents, Gd-DTPA, Gd-DTPA-BMA and Gd-DOTA, using Electron Paramagnetic Resonance(EPR) technique. Material and Methods: The paramagnetic MR contrast agents, Gd-DTPA(Magnevist), Gd-DTPA-BMA(OMNISCAN) and Gd-DOTA(Dotarem), were used for this study. The EPR spectra of these contrast agents, which were prepared 2:1 methanol/water solution, were obtained at low temperatures, from-160degrees C~-20degrees C. The glassy-state EPR spectra for these contrast agents were then fitted by the simulation spectra generated with different zero-field splitting (ZFS) parameters by a computer simulation program 'GE N', which generates the EPR powder spectrum using a given ZFS in 3X3 tensor. Finally, the spin relaxation times of the contrast agents were then determined from the T2e, D, and E values of the best simulation spectra using the McLachlan's theory of average relaxation rate. Results: The electronic transverse spin relaxation times, T2e's, of Gd-DTPA, Gd-DTPA-BMA and Gd-DOTA were 0.113ns, 0.147ns and 1.81ns respectively. The g-values were 1.9737, 1.9735 and 1.9830 and the electronic spin relaxation times, T1e's, were 18.70ns, 33.40ns and 1.66micros, respectively. Conclusion: The results of these studies reconfirm that the paramagnetic MR contrast agents with larger ZFS parameters should have shorter T1e's. Among three contrast agents used for this study, Gd-DOTA chelated with cyclic ligand structure shows better electronic property then the others with linear structure. Thus, it is concluded that the exact determination of ZFS parameters is the important factor in evaluating relaxation enhancement effect of the agents and in developing new contrast agents.
Computer Simulation ; Contrast Media* ; Gadolinium DTPA ; Magnetic Resonance Imaging* ; Relaxation*