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: 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*

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 assess the usefulness of diffusion-weighted MR imaging (DWI) and apparent diffusion coefficient (ADC) in the initial and follow-up studies of patients with neuro-Behcet's disease. MATERIALS AND METHODS: Six patients diagnosed with neuro-Behcet's disease were the subjects of this study. Initial and follow-up MR imaging were obtained in all six patients. Initial and follow-up DWI were also obtained in four of the six patients, with only an initial DWI in the other two. The DWI were obtained using multi-shot echo planar imaging, on a 1.5T MR unit, with two gradient steps (b values of 0, 1000 sec/mm2). The ADC value and ADC maps were obtained using commercial software. The locations and signal intensities of the lesions were analyzed on conventional MRI and DWI, respectively. The ADC values of the lesions were calculated on the initial and follow-up DWI, and compared those of lesions in the normal contralateral regions. RESULTS:The initial DWI showed iso-signal intensities in four of the six patients, with high signal intensities in the other two. In five of the six patients, including three of the four that showed isosignal intensities and the two that showed high signal intensities on the initial DWI, the ADC values of the involved lesions were higher than those of the normal contralateral regions. In three of four that showed isosignal intensities, the ADC values of the lesions were decreased and normalized on the follow-up DWI. CONCLUSION: Obtaining DWI and ADC values in patients with neuro-Behcet's disease may be helpful in the understanding of pathophysiology and differential diagnosis of this disease.
Diagnosis, Differential ; Diffusion ; Echo-Planar Imaging ; Follow-Up Studies* ; Humans ; Magnetic Resonance Imaging*

PURPOSE: To report the use of multiband accelerated echo-planar imaging (EPI) for resting-state functional MRI (rs-fMRI) to achieve rapid high temporal resolution at 3T compared to conventional EPI. MATERIALS AND METHODS: rs-fMRI data were acquired from 20 healthy right-handed volunteers by using three methods: conventional single-band gradient-echo EPI acquisition (Data 1), multiband gradient-echo EPI acquisition with 240 volumes (Data 2) and 480 volumes (Data 3). Temporal signal-to-noise ratio (tSNR) maps were obtained by dividing the mean of the time course of each voxel by its temporal standard deviation. The resting-state sensorimotor network (SMN) and default mode network (DMN) were estimated using independent component analysis (ICA) and a seed-based method. One-way analysis of variance (ANOVA) was performed between the tSNR map, SMN, and DMN from the three data sets for between-group analysis. P < 0.05 with a family-wise error (FWE) correction for multiple comparisons was considered statistically significant. RESULTS: One-way ANOVA and post-hoc two-sample t-tests showed that the tSNR was higher in Data 1 than Data 2 and 3 in white matter structures such as the striatum and medial and superior longitudinal fasciculus. One-way ANOVA revealed no differences in SMN or DMN across the three data sets. CONCLUSION: Within the adapted metrics estimated under specific imaging conditions employed in this study, multiband accelerated EPI, which substantially reduced scan times, provides the same quality image of functional connectivity as rs-fMRI by using conventional EPI at 3T. Under employed imaging conditions, this technique shows strong potential for clinical acceptance and translation of rs-fMRI protocols with potential advantages in spatial and/or temporal resolution. However, further study is warranted to evaluate whether the current findings can be generalized in diverse settings.
Dataset ; Echo-Planar Imaging* ; Magnetic Resonance Imaging* ; Methods ; Signal-To-Noise Ratio ; Volunteers ; White Matter