PURPOSE: We undertook this study to evaluate breath-hold Half-Fourier Acquisition Single-shot TSE(HASTE) andsingle-shot echo planar MR imaging for the detection of focal hepatic masses. MATERIALS AND METHODS: Using a 1.5Tsuperconductive system, HASTE, vascular dephasing inversion recovery spin echo EP(VDIR-SE-EP), inversion recoveryspin echo EP(IR-SE-EP), and free induction decay EP(FID-EP) were performed in 31 patients with 34 focal livermasses. Images were compared on the basis of detection sensitivity of focal hepatic masses, liver signal-to-noiseratio(S/N), lesion-to-liver contrast-to-noise ratio(C/N), and image quality. Images analysis was performed by tworadiologists, who reached a consensus. RESULT: The detection sensitivity of focal hepatic masses with HASTE was94.1%, with VDIR-SE-EP and IR-SE-EP, this was 91.2%, and with FID-EP, the figure was 88.2%. Liver S/Ns werehighest on HASTE images, which were significantly better(p<.05) than the three types of EP image. Overalllesion-to-liver C/Ns were highest on VDIR-SE-EP and IR-SE-EP(p<.05). Lesion-to-liver C/Ns were highest onVDIR-SE-EP and IR-SE-EP for solid lesions, but for non-solid lesions, were highest on HASTE (p<.05). Compared withHASTE images, EP images were poor. CONCLUSION: For the detection of focal hepatic masses, the sensitivity ofVDIR-SE-EP and IR-SE-EP was similar to that of HASTE. When using the former, acquisition time was substantiallyreduced but image quality was poor.
Consensus ; Echo-Planar Imaging* ; Humans ; Liver ; Magnetic Resonance Imaging*

OBJECTIVE: To compare the apparent diffusion coefficient (ADC) value using single-shot echo-planar imaging sequences at 3T and 1.5T for differentiation of benign fracture edema and tumor infiltration of the vertebral body. MATERIALS AND METHODS: A total of 46 spinal examinations were included in the 1.5T MRI group, and a total of 40 spinal examinations were included in the 3T MRI group. The ADC values of the lesion were measured and calculated. The diagnostic performance of the conventional MR image containing sagittal T2-weighted fat saturated image and each diffusion weighted image (DWI) with an ADC value with different b values were evaluated. RESULTS: The mean ADC value of the benign lesions was higher than that of the malignant lesions on 1.5T and 3T (p < 0.05). The sensitivity of the diagnostic performance was higher with an additional DWI in both 1.5T and 3T, but the sensitivities were similar with the addition of b values of 400 and 1000. The specificities of the diagnostic performances did not show significant differences (p value > 0.05). The diagnostic accuracies were higher when either of the DWIs (b values of 400 and 1000) was added to routine MR image for 1.5T and 3T. Statistical differences between 1.5T and 3T or between b values of 400 and 1000 were not seen. CONCLUSION: The ADC values of the benign lesions were significantly higher than those of the malignant lesions on 1.5T and 3T. There was no statistically significant difference in the diagnostic performances when either of the DWIs (b values of 400 and 1000) was added to the routine MR image for 1.5T and 3T.
Diffusion ; Echo-Planar Imaging ; Edema* ; Magnetic Resonance Imaging* ; Spine

PURPOSE: To evaluate the feasibility of functional MR imaging(fMRI) using the echo-planar imaging (EPI)technique to map the motor speech center and to provide the basic data for motor speech fMRI during internal wordgeneration. MATERIALS AND METHODS: This study involved ten young, healthy, right-handed volunteers (M:F=8:2 ;Age: 21-27) ; a 1.5 T whole body scanner with multislice EPI was used. Brain activation was mapped using gradientecho single shot EPI(TR/TE of 3000/40, slice numbers 6, slice thickeness 10 mm, no interslice gap, matrix numbers128x128, and FOV 30x30). The paradigm consisted of a series of alternating rest and activation tasks, repeatedeight times. During the rest task, each of ten Korean nouns composed of two to four syllables was showncontinuously every 3 seconds. The subjects were required to see the words but not to generate speech, whereasduring the activation task, they were asked to internally generate as many words as possible from each of tennon-concrete one-syllabled Korean letters shown on the screen every 3 seconds. During an eight-minute period, atotal of 960 axial images were acquired in each subject. Data were analyzed using the Z-score(p<0.05), andfollowing color processing, the activated signals were overlapped on T1-weighted images. The location of theactivated area, mean activated signal intensity change (%), mean activated pixel numbers, and the presence ofcyclic change in signal intensity were evaluated. RESULTS: In seven subjects, activation was observed in the leftBroca's area and its adjacent areas(Brodmann areas 44, 45, 46, 6 and 10) ; in three of the seven, activation inBroca's areas was bilateral. In two of the remaining three subjects, the medial portion of the frontal lobe wasactivated, while in the other, there was no significant signal change in any area. Mean activated signal changewas 2.6+/-1.3% in the left Broca's area and 1.2+/-1.7% in the right, while the mean number of activated pixels was67+/-46 in the left area and 23+/-33 in the right. Periodic cyclic signal change according to rest and activationwas seen in the left Broca's area in four subjects, in the bilateral Broca's area in two, and in the medialportion of the frontal lobe in two. CONCLUSION: The results of this study indicate that in most subjects, fMRIusing EPI can effectively map the motor speech center. The data obtained may be useful for the clinicalapplication of fMRI.
Brain ; Echo-Planar Imaging ; Frontal Lobe ; Magnetic Resonance Imaging* ; Volunteers

PURPOSE: To determine the best MR sequence for evaluation of the anatomical structures of normal kidney. MATERIALS AND METHODS: Twenty normal volunteers (M:F=15:5) took part in this study, and for each, seven sequences were performed. The T1 weighted sequences were conventional spin echo T1 (Conv-SET1), turbo spin echo T1 (TSET1), and fast low angle shot (FLASH), while the T2 weighted sequences were turbo spin echo T2 (TSET2), half-Fourier acquisition single-shot turbo spin echo (HASTE), true-fast imaging with steady-state precession (True-FISP), and echoplanar imaging (EPI). The study involved quantitative and qualitative analysis. In quantitative analysis, CNRs between cortex and adjacent fat tissue, and between cortex and medulla were calculated from SNR (signal to noise ratio), and the CNRs of sequences were statistically compared. In quantative analysis, three radiologists collectively evaluated kidney outline, corticomedullary division, the renal vessels, the pelvis/ureter, and artifacts. For each sequence a grade was assigned, and for each parameter the grades were compared. RESULTS: Between cortex and adjacent fat, the highest CNR was shown by TSET1, followed by Conv-SET1,while among T2 sequences, the CNR shown by TSET2 was highest. Between cortex and medulla, the CNR demonstrated by the three T1 sequences showed no statistically significant difference. Among T2 sequences, however, HASTE showed the highest CNR, followed by EPI, and statistically, the findings for these two were significantly different from those of other T2 sequences. Among T1 sequences, FLASH provided the best kidney outline, though among T2-sequences there was no statistically significant difference. FLASH was also the best for cortico-medullary distinction, while for this purpose the best T2 sequence was HASTE. True-FISP was best for the evaluation of renal vessels, and HASTE for evaluating the pelvis and ureter. Artifacts were most prominent on Conv SET1. CONCLUSION: For evaluating the shape of the kidney, the best T2 sequence was TSET2, but the best T1 sequence could not be determined. For cortico-medullary differentiation, the best T1 sequence was FLASH and the best T2 sequence was HASTE. For the evaluation of renal vessels, True-FISP was best, and for the pelvis and ureter, HASTE. Artifacts were most prominent on Conv-SET1.
Artifacts ; Echo-Planar Imaging ; Healthy Volunteers ; Kidney ; Noise ; Pelvis ; Ureter

PURPOSE: To assess the values of parametric "maximum slope(MS) and blood volume(BV)" images as indicators of tissue vascularization and perfusion in distinguishing benign from malignant musculoskeletal tumors. MATERIAL AND METHODS: Dynamic inversion recovery spin-echo echo-planar imaging (TR/TE/TI/NEX: 1 5 0 0 / 2 4 / 5 00 ms/1; matrix 128 x 128; slice thickeness 5 mm, interleaved) at 1.5-second intervals(200 phases) was performed after intravenous bolus injection of Gd-DTPA. A total of 32 pathologically proven muscu-loskeletal masses(benign 9, malignant 23) were included in this study. MS was derived by fitting a time-intensity curve using a polynomial model. BV was determined by integration until maximum slope was reached. On a pixel-by-pixel basis, MS and BV images were generated and displayed by gray-scale. We selected a region of interest(ROI, more than 6 x 6 pixels) including the highest value of the tumors and calculated mean values of MS and BV. Wilcoxon's signed rank test was used to compare benign tumors with malignant pre- and postchemotherapy tumors. RESULT: The mean values of ROIs selected on MS images were significantly different (p=.008) between benign (mean 3.33, range 0.01 -16.47 ) and prechemotherapy malignant(mean 8.54, range 1.61 -16.90) tumors, as were the mean values of ROIs on BV images(p=.005; benign tumors: mean 162.17, range 91.17 -2 8 3 . 7 ; prechemotherapy malignant tumors: mean 330.18, range 117.5 -845.1). MS and BV values of benign and malignant tumors overlapped but tended to be separated. CONCLUSION: BV and MS images may help distinguish benign from malignant musculoskeletal tumors.
Blood Volume* ; Echo-Planar Imaging ; Gadolinium DTPA ; Models, Statistical ; Perfusion

PURPOSE: To assess the values of parametric "maximum slope(MS) and blood volume(BV)" images as indicators of tissue vascularization and perfusion in distinguishing benign from malignant musculoskeletal tumors. MATERIAL AND METHODS: Dynamic inversion recovery spin-echo echo-planar imaging (TR/TE/TI/NEX: 1 5 0 0 / 2 4 / 5 00 ms/1; matrix 128 x 128; slice thickeness 5 mm, interleaved) at 1.5-second intervals(200 phases) was performed after intravenous bolus injection of Gd-DTPA. A total of 32 pathologically proven muscu-loskeletal masses(benign 9, malignant 23) were included in this study. MS was derived by fitting a time-intensity curve using a polynomial model. BV was determined by integration until maximum slope was reached. On a pixel-by-pixel basis, MS and BV images were generated and displayed by gray-scale. We selected a region of interest(ROI, more than 6 x 6 pixels) including the highest value of the tumors and calculated mean values of MS and BV. Wilcoxon's signed rank test was used to compare benign tumors with malignant pre- and postchemotherapy tumors. RESULT: The mean values of ROIs selected on MS images were significantly different (p=.008) between benign (mean 3.33, range 0.01 -16.47 ) and prechemotherapy malignant(mean 8.54, range 1.61 -16.90) tumors, as were the mean values of ROIs on BV images(p=.005; benign tumors: mean 162.17, range 91.17 -2 8 3 . 7 ; prechemotherapy malignant tumors: mean 330.18, range 117.5 -845.1). MS and BV values of benign and malignant tumors overlapped but tended to be separated. CONCLUSION: BV and MS images may help distinguish benign from malignant musculoskeletal tumors.
Blood Volume* ; Echo-Planar Imaging ; Gadolinium DTPA ; Models, Statistical ; Perfusion

PURPOSE: To determine changes in the signal intensity of intracerebral hemorrhagic lesions according to the time interval, between the onset of symptoms and MR imaging in the T1-weighted (T1W1), T2-weighted (T2W1) and diffusion-weighted modes. MATERIALS AND METHODS: Thirty-four patients with hemorrhagic stroke who underwent DWI and conventional MRI were involved in this study. Hemorrhagic phase was determined according to the time interval between the onset of symptoms and MR scanning, and was as follows: acute (3 days or less): eight patients); early subacute (7 days or less): ten patients; late subacute (4 weeks or less): seven patients; early chronic (3 months or less) : four patients); and late chronic (more than 3 months): five patients. Using a 1.5T MR imager and the single-shot echo-planar imaging technique, T1-weighted, fast spin-echo T2-weighted, and diffusion-weighted were obtained. In all cases qualitative signal intensity (SI) at the center of a lesion was recorded, and the ratio between this and normal brain parenchyma was calculated. RESULTS: SI at the center of a lesion was found to be iso or high/high/high (T1WI/T2WI/DWI) in five of eight acute-phase cases (interval of 24 hours or less) and low/low/low in the remaining three (interval of 72 hours or less). Other signal intensities were as follows: early subacute phase: high/low/low (all ten cases); late subacute phase: high/high/high (all seven cases); early chronic phase: high/high/high (all four cases); late chronic phase: low/high/low (all five cases). Mean SIRs were as follows: in the five acute-phase cases in which SI was iso or high: 1.42+/-0.78 / 2.58+/-0.84 / 1.35+/-0.08 (T1WI / T2WI / DWI); in the remaining three acute-phase cases: 0.94 +/-0.18 / 0.63+/-0.16 / 0.27+/-0.10; in the early subacute phase, 1.35+/-0.01 / 0.97+/-0.21 / 0.86+/-0.22 in early subacute phase, 1.58+/-0.04 / 1.54+/-0.09 / 1.44+/-0.14; in the early chronic phase: 1.26+/-0.11 / 1.06+/-0.14 / 0.97+/-0.12; and in the late chronic phase: 0.65+/-2.23 / 1.51+/-0.12 / 0.23+/-0.18. CONCLUSION: The DWI findings of intracerebral hemorrhage reflect the findings of T2WI. When interpreting the DWI findings in patients with intracerebral hemorrhage, an understanding of the temporal evolution of this is very helpful.
Brain ; Cerebral Hemorrhage ; Diffusion* ; Echo-Planar Imaging ; Humans ; Intracranial Hemorrhages* ; Magnetic Resonance Imaging ; Stroke

Functional MRI (fMRI) provides an indirect mapping of cerebral activity, based on the detection of the local blood flow and oxygenation changes following neuronal activity (Blood Oxygenation Level Dependent). fMRI allows us to study noninvasively the normal and pathological aspects of functional cortical organization. Each fMRI study compares two different states of activity. Echo-Planar Imaging is the technique that makes it possible to study the whole brain at a rapid pace. Activation maps are calculated from a statistical analysis of the local signal changes. fMRI is now becoming an essential tool in the neurofunctional evaluation of normal volunteers and many neurological patients as well as the reference method to image normal or pathologic functional brain organization.
Brain* ; Echo-Planar Imaging ; Healthy Volunteers ; Humans ; Magnetic Resonance Imaging* ; Neurons ; Oxygen

PURPOSE: To investigate the efficiency or potency of functional MRI (fMRI) for the determination of language dominance by comparing the results of fMRI with those of the Wada test. MATERIALS AND METHODS: Among 34 patients with intractable seizure who underwent both fMRI and the Wada test, we analyzed the results of 30 (men:women=19:11; mean age=29.7 years). Using echoplanar imaging and the blood oxygen level dependent technique, fMRI was performed using a 1.5 T MR imager with a standard head coil. The language task consisted of two parts: reading words and generating words. For fMRI, a multi-event multi-task paradigm consisting of two sets of activation, rest, and alternative periods was used. Image processing involved the use of the Z test (Z threshold = 1.0 -1.2). To determine the lateralization index, we calculated the activation pixels within the whole frontal cortex., and to ascertain the discrepancy between the two tasks, the clustering grade of activation pixels was measured. After the injection of thiopental, language dominance was determined by means of a modified Wada test. The results of this and the findings of fMRI were compared with the results of Fisher 's exact test (p < 0.05). RESULTS: The correlation indices between the findings of fMRI and the results of the Wada test were 77% for word generation and 50% for reading. The diference was only marginally significant (p = 0.06). For the two tasks, the opposite results were 33% for reading and 3.3% for word generation, and these were significantly different (p < 0.05). The clustering grade for more than one unit was 40% for word generation, and 23% for readings, a difference which was not statistically significant(p> 0.05). CONCLUSION: For the determinaton of language dominance, fMRI showed good correlation with the Wada test. The word generation task was more efficient than the reading task. fMRI which is non-invasive and repeatable, is therefore more efficient and useful than the invasive Wada test.
Brain ; Echo-Planar Imaging ; Head ; Humans ; Magnetic Resonance Imaging* ; Oxygen ; Reading ; Seizures* ; Thiopental

PURPOSE: To separate and evaluate the low frequency spontaneous fluctuation BOLD signals from the functional magnetic resonance imaging data using sensorimotor active task. MATERIALS AND METHODS: Twenty female archery players and twenty three control subjects were included in this study. Finger-tapping task consisted of three cycles of right finger tapping, with a subsequent 30 second rest. Blood oxygenation level-dependent (BOLD) data were collected using T2*-weighted echo planar imaging at a 3.0 T scanner. A 3-D FSPGR T1-weighted images were used for structural reference. Image processing and statistical analyses were performed using SPM5 for active finger-tapping task and GIFT program was used for statistical analyses of low frequency spontaneous fluctuation BOLD signal. RESULTS: Both groups showed the activation in the left primary motor cortex and supplemental motor area and in the right cerebellum for right finger-tapping task. ICA analysis using GIFT revealed independent components corresponding to contralateral and ipsilateral sensorimotor network and cognitive-related neural network. CONCLUSION: The current study demonstrated that the low frequency spontaneous fluctuation BOLD signals can be separated from the fMRI data using finger tapping paradigm. Also, it was found that these independent components correspond to spontaneous and coherent neural activity in the primary sensorimotor network and in the motor-cognitive network.
Cerebellum ; Echo-Planar Imaging ; Female ; Fingers ; Humans ; Magnetic Resonance Imaging ; Motor Cortex ; Oxygen