Digital Tomosynthesis for PNS Evaluation: Comparisons of Patient Exposure and Image Quality with Plain Radiography

OBJECTIVE: We investigated low dose digital tomosynthesis (DT) for the evaluation of the paranasal sinus (PNS), and compared its diagnostic accuracy with a PNS radiography series (XR). MATERIALS AND METHODS: We enrolled 43 patients for whom XR, PNS DT, and OMU CT were performed. We measured effective doses (EDs) of XR, DT, and OMU CT using Monte Carlo simulation software. Two radiologists performed independent observation of both XR and DT. For seven PNSs, they scored anatomic conspicuity of sinuses and confidence on the presence of sinusitis using nine point scales. OMU CT was observed by the third radiologist and the findings were regarded as reference standard. We compared scores for conspicuity and sinusitis confidence between XR and DT. RESULTS: Mean EDs were 29 +/- 6 microSv, 48 +/- 10 microSv, and 980 +/- 250 microSv, respectively, for XR, DT, and CT. Mean scores for conspicuity were 6.3 and 7.4, respectively, for XR and DT. Sensitivity per patient basis for sinusitis detection were 52% and 96%, respectively, for XR and DT in observer 1 (p = 0.001) and 80% and 92% for observer 2 (p = 0.25). Specificities for sinusitis exclusion were 100% for both XR and DT for observer 1 and 89% and 100% for observer 2 (p = 0.50). Accuracies for sinusitis diagnosis were 72% and 98%, respectively, for XR and DT for observer 1 (p = 0.001) and 84% and 95% for observer 2 (p = 0.125). CONCLUSION: Patient radiation dose from low dose DT is comparable with that of PNS XR. Diagnostic sensitivity of DT for sinusitis was superior to PNS XR.

Endovascular Coil Embolization of Very Small Intracranial Aneurysms

OBJECTIVE: We aimed to evaluate the results of endovascular coil embolization for very small aneurysms ( or = 4), with no bleeding of the treated aneurysms during a mean follow-up period of 13.3 months. On 27 follow-up MRA, there was no recurrence, and the five incompletely occluded aneurysms showed a spontaneous amelioration resulting in an adequate occlusion. CONCLUSION: Coil embolization of very small aneurysms is technically feasible with good results. The long-term efficacy and the potential as a standard treatment strategy remain to be determined by randomized large trials.

Recent Trends in the Treatment of Cerebral Aneurysms: Comparison between Endovascular Coil Embolization and Surgical Clipping / 신경중재치료의학

Surgical clipping has been the gold standards in the treatment of cerebral aneurysms. In 1990, Guglielmi detachable coil was introduced into clinical use, and was approved by FDA in 1995. After the ISAT results in 2002, endovascular coil embolization of cerebral aneurysms has been accepted and regarded as equal or better alternative. From 2003 to 2007, numbers of endovascular coil embolization of cerebral aneurysms has increased two-fold while surgical clipping has remained stable in Korea. Total numbers of aneurysm treatment has been increased by 40%, endovascular coil embolization has been increased by 229% (p < 0.001), but surgical clipping has been increased by 5.6%. This result suggests there is paradigm shift in the treatment of cerebral aneurysms.

Carotid Endarterectomy: Analysis of Early Complications (<30 days) and Risk Factors for Postoperative New Brain Infarction

PURPOSE: We aimed to evaluate the early (70%) carotid stenosis. We also found that plaque with ulceration was a significant risk factor for the development of postoperative NBI.

Ethanol Sclerotherapy for the Management of Craniofacial Venous Malformations: the Interim Results

OBJECTIVE: We wanted to evaluate the safety and feasibility of ethanol sclerotherapy for treating craniofacial venous malformations (CVMs). MATERIALS AND METHODS: From May 1998 to April 2007, 87 patients (40 men and 47 women; age range, 2-68 years) with CVMs underwent staged ethanol sclerotherapy (range, 1-21 sessions; median number of sessions, 2) by the direct puncture technique. Clinical follow up (range, 0-120 months; mean follow up, 35 months; median follow up, 28 months) was performed for all the patients. Therapeutic outcomes were established by evaluating the clinical outcome of the signs and symptoms in all patients, as well as the degree of devascularization, which was determined on the follow-up imaging, in 71 patients. RESULTS: A total of 305 procedures with the use of ethanol were performed in 87 patients. Follow-up imaging studies were performed for 71 of 87 patients. Twenty-three (32%) of the 71 patients showed excellent outcomes, 37 patients (52%) showed good outcomes and 11 patients (16%) showed poor outcomes. Ethanol sclerotherapy was considered effective for 60 patients. All the minor complications such as bulla (n = 5) healed with only wound dressing and observation. Any major complication such as skin necrosis did not develop. CONCLUSION: Percutaneous ethanol sclerotherapy is an effective, safe treatment for CVMs.

Endovascular Treatment for a Persistent Trigeminal Artery Aneurysm Presenting as Isolated Sixth Nerve Palsy / 신경중재치료의학

The trigeminal artery is the most common persistent carotid-basilar anastomotic channel observed in adult life, and its occurrence probably represents a defect in cerebrovascular development. It can be associated with other congenital abnormalities such as cerebral aneurysms, but only rarely do aneurysms of the persistent trigeminal artery itself arise. Endovascular treatment of these aneurysms has not been attempted so much. We report a case of endovascular treatment for a persistent trigeminal artery aneurysm causing isolated sixth nerve palsy.

Cerebral Ischemia Detected with Diffusion-Weighted MR Imaging after Protected Carotid Artery Stenting: Comparison of Distal Balloon and Filter Device

OBJECTIVE: The aim of this study was to examine the incidence of ischemia during protected carotid artery stenting (CAS) as well as to compare the protective efficacy of the balloon and filter devices on diffusion-weighted MR imaging (DWI). MATERIALS AND METHODS: Seventy-one consecutive protected CAS procedures in 70 patients with a severe (> 70%) or symptomatic moderate (> 50%) carotid artery stenosis were examined. A balloon device (PercuSurge GuardWire) and a filter device (FilterWire EX/EZ, Emboshield) was used in 33 cases (CAS-B group) and 38 cases (CAS-F group) to prevent distal embolization, respectively. All the patients underwent DWI within seven days before and after the procedures. The number of new cerebral ischemic lesions on the post-procedural DWI were counted and divided into ipsilateral and contralateral lesions according to the relationship with the stenting side. RESULTS: New cerebral ischemic lesions were detected in 13 (39.4%) out of the 33 CAS-Bs and in 15 (39.5%) out of the 38 CAS-Fs. The mean number of total, ipsilateral and contralateral new cerebral ischemic lesion was 2.39, 1.67 and 0.73 in the CAS-B group and 2.11, 1.32 and 0.79 in the CAS-F group, respectively. No statistical differences were found between the two groups (p = 0.96, 0.74 and 0.65, respectively). The embolic complications encountered included two retinal infarctions and one hemiparesis in the CAS-B group (9.09%), and one retinal infarction, one hemiparesis and one ataxia in the CAS-F group (7.89%). There was a similar incidence of embolic complications in the two groups (p = 1.00). CONCLUSION: The type of distal protection device used such as a balloon and filter does not affect the incidence of cerebral embolization after protected CAS.

Rescue Balloon Reposition of the Protruding Coil Loops during Endovascular Treatment of An Anterior Communicating Artery Aneurysm: A Case Report / 신경중재치료의학

Protrusion of coil loop(s) and subsequent occlusion of the parent artery is one of the dreadful complications during endovascular coil embolization of cerebral aneurysm. Although protrusion of one or two coil loops may not cause adverse events and can be ignored in many instances, it can also compromise the parent artery in some cases with or without thrombus formation. We report a case of rescue balloon reposition of the protruding coil mass back into the aneurysm and recanalization of parent artery during embolization of the anterior communicating artery aneurysm.

Structural Brain Abnormalities in Juvenile Myoclonic Epilepsy Patients: Volumetry and Voxel-Based Morphometry

OBJECTIVE: We aimed to find structural brain abnormalities in juvenile myoclonic epilepsy (JME) patients. MATERIALS AND METHODS: The volumes of the cerebrum, hippocampus and frontal lobe and the area of the corpus callosum's subdivisions were all semi-automatically measured, and then optimized voxel-based morphometry (VBM) was performed in 19 JME patients and 19 age/gender matched normal controls. RESULTS: The rostrum and rostral body of the corpus callosum and the left hippocampus were significantly smaller than those of the normal controls, whereas the volume of the JME's left frontal lobe was significantly larger than that of the controls. The area of the rostral body had a significant positive correlation with the age of seizure onset (r = 0.56, p = 0.012), and the volume of the right frontal lobe had a significant negative correlation with the duration of disease (r = -0.51, p = 0.025). On the VBM, the gray matter concentration of the prefrontal lobe (bilateral gyri rectus, anterior orbital gyri, left anterior middle frontal gyrus and right anterior superior frontal gyrus) was decreased in the JME group (corrected p < 0.05). CONCLUSION: The JME patients showed complex structural abnormalities in the corpus callosum, frontal lobe and hippocampus, and also a decreased gray matter concentration of the prefrontal region, which all suggests there is an abnormal neural network in the JME brain.

Efficacy of Femoral Vascular Closure Devices in Patients Treated with Anticoagulant, Abciximab or Thrombolytics during Percutaneous Endovascular Procedures

OBJECTIVE: This study assessed the outcomes of using vascular closure devices following percutaneous transfemoral endovascular procedures in the patients who were treated with heparin, abciximab or thrombolytics (urokinase or t-PA) during the procedures. MATERIALS AND METHODS: From March 28, 2003 to August 31, 2004, we conducted a prospective and randomized study in which 1,676 cases of 1,180 patients were treated with one of the two different closure devices (the collagen plug device was Angio-SealTM; the suture-mediated closure device was The Closer STM) at the femoral access site after instituting percutaneous endovascular procedures. Among the 1,676 cases, 108 cases (the drug group) were treated with heparin only (n = 94), thrombolytics only (n = 10), heparin and thrombolytics (n = 3), or abciximab and thrombolytics (n = 1) during the procedures; 1,568 cases (the no-drug group) were treated without any medication. We compared the efficacy and complications between the two groups. Of the drug group, 42 cases underwent arterial closures with the collagen plug devices and 66 cases underwent arterial closures with the suture-mediated closure devices. We also compared the efficacy and complications between these two groups. RESULTS: The immediate hemostasis rates were 92.9% (1,456/1,568) in the no-drug group and 91.7% (99/108) in the drug group. Early complications occurred in four cases of the drug group. These included two episodes of rebleeding with using the Closer S, which required manual compression for at least 10 minutes, and two episodes of minor oozing with using one Angio-Seal and one Closer S, which required two hours of additional bed rest. There was no late complication. So, the total success rates were 90.8% (1,423/1,568) in the no-drug group and 88.0% (95/108) in the drug group. These results were not significantly different between the two groups (p = 0.34). In the drug group, the difference of the successful hemostasis rate between the collagen plug devices and the suture-mediated devices was also not statistically significant (92.9% vs. 84.8%, respectively; p = 0.21). CONCLUSION: Arterial closure of the femoral access site with using vascular closure devices is both safe and effective, even in the patients who received heparin, abciximab or thrombolytics.

Prospective Comparison of Collagen Plug (Angio-SealTM) and Suture-Mediated (the Closer STM) Closure Devices at Femoral Access Sites

OBJECTIVE: Rapid and effective hemostasis at femoral puncture sites minimizes both the hospital stay and patient discomfort. Therefore, a variety of arterial closure devices have been developed to facilitate the closure of femoral arteriotomy. The objective of this prospective study was to compare the efficacy of two different closure devices; a collagen plug device (Angio-Seal) and a suture-mediated closure device (the Closer S). MATERIALS AND METHODS: From March 28, 2003 to August 31, 2004, we conducted a prospective study in which 1, 676 cases of 1, 180 patients were treated with two different types of closure device. Angio-Seal was used in 961 cases and the Closer S in 715 cases. The efficacy of the closure devices was assessed, as well as complications occurring at the puncture sites. RESULTS: Successful immediate hemostasis was achieved in 95.2% of the cases treated with Angio-Seal, and in 89.5% of the cases treated with the Closer S (p < 0.05). The rates of minor and major complications occurring between the two groups were not significantly different. In the Closer S group, we observed four major complications (0.6%), that consisted of one massive retroperitoneal hemorrhage (surgically explored) and three pseudoaneurysms. In the Angio-Seal group, we observed three major complications (0.3%) that consisted of one femoral artery occlusion, one case of infection treated with intravenous antibiotics and one pseudoaneurysm. CONCLUSION: The use of Angio-Seal was found to be more effective than that of the Closer S with regard to the immediate hemostasis of the femoral puncture sites. However, we detected no significant differences in the rate at which complications occurred.

Diagnosis and Treatment of Extracranial Arteriovenous Malformations in the Head and Neck Region / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Arteriovenous malformation is a vascular malformation with fast-flow shunt from the artery to the vein. Extracranial arteriovenous malformation in the head and neck (HNAVM) is so rare that there have been no systematical reports related to it in Korea. Authors aimed to suggest the treatment protocols for HNAVM through retrospective analysis. SUBJECTS AND METHOD: We reviewed retrospectively the medical records of 19 patients with extracranial HNAVM, who had been diagnosed and treated between 1995 and 2001. Mean follow-up duration was 27.3 months. The mean age at detection was 13.2 years old. The cheek was the most frequently suffered site. We used MRI, angiography, and 99mTechnetium (Tc) RBC scintigraphy for the diagnosis and follow-up of HNAVM. For the treatment, ethanol sclerotherapy, excision, and embolization were adopted alone or in variable combination. RESULTS: Angiography was confirmative of the diagnosis and MRI was excellent in evaluating the extent of the disease. Ethanol sclerotherapy was used as the first line of treatment for 11 cases. For others, surgical excision combined with embolization was used as the first line of treatment for 7 patients and the second choice for 6 patients. 99mTc RBC scintigraphy was useful in quantifying the response after treatment. Fifteen out of 19 patients finally achieved 75% or more reduction in their size of lesions. There were 5 permanent complications from the total of 37 procedures. CONCLUSION: For those cases of HNAVM that had the nidus accessible via the percutaneous route, ethanol sclerotherapy worked as the first-line treatment. For other HNAVM cases, surgical excision with embolization might be the best choice of treatment.

Treatment of a Sequential Giant Fusiform Aneurysm of the Basilar Trunk

We report an exceptional case of a de novo giant fusiform aneurysm of the basilar trunk, which developed shortly after the therapeutic occlusion of the right internal carotid artery for a fusiform carotid aneurysm. It would appear to be appropriate to call this entity a sequential giant fusiform aneurysm. The patient was successfully treated with endovascular occlusion of the giant basilar trunk aneurysm following bypass surgery.

Assessment of Tissue Viability Using Diffusion- and Perfusion-Weighted MRI in Hyperacute Stroke

OBJECTIVE: The aim of this study was to investigate the relationship between the diffusion and perfusion parameters in hyperacute infarction, and we wanted to determine the viability threshold for the ischemic penumbra using diffusion- and perfusion-weighted imaging (DWI and PWI, respectively). MATERIALS AND METHODS: Both DWI and PWI were performed within six hours from the onset of symptoms for 12 patients who had suffered from acute stroke. Three regions of interest (ROIs) were identified: ROI 1 was the initial lesion on DWI; ROI 2 was the DWI/PWI mismatch area (the penumbra) that progressed onward to the infarct; and ROI 3 was the mismatch area that recovered to normal on the follow-up scans. The ratios of apparent diffusion coefficient (ADC), the relative cerebral blood volume (rCBV), and the time to peak (TTP) were calculated as the lesions' ROIs divided by the contralateral mirror ROIs, and these values were then correlated with each other. The viability threshold was determined by using the receiver operating characteristic (ROC) curves. RESULTS: For all three ROIs, the ADC ratios had significant linear correlation with the TTP ratios (p < 0.001), but not with the rCBV ratios (p = 0.280). There was no significant difference for the ADC and rCBV ratios within the ROIs. The mean TTP ratio/TTP delay between the penumbras' two ROIs showed a significant statistical difference (p < 0.001). The cutoff value between ROI 2 and ROI 3, as the viability threshold, was a TTP ratio of 1.29 (with a sensitivity and specificity of 86% and 73%, respectively) and a TTP delay of 7.8 sec (with a sensitivity and specificity of 84% and 72%, respectively). CONCLUSION: Determining the viability thresholds for the TTP ratio/delay on the PWI may be helpful for selecting those patients who would benefit from the various therapeutic interventions that can be used during the acute phase of ischemic stroke.

Cortical Representation to Odorant Stimulation: Statistical Non-parametric Mapping of Low Resolution Electro magnetic Tomography (LORETA)

BACKGROUND: Although olfactory stimulation has been known to produce effects on human mood and cognition, the specific EEG patterns of activity was reported diversely. The purpose of this study was to investigate EEG changes by odorant using low resolution electromagnetic tomography (LORETA) in young healthy subjects. METHODS: The EEG's of nineteen (10 males, 9 females) non-smoking right-handed college students were recorded after odorant stimulation. A nineteen-channel EEG was recorded referenced to linked ears before and during olfactory stimulation. Olfactory stimulation was presented with lavender essential oil by blotter method. The LORETA power was computed from ten 2-s epochs, separately for the different EEG frequencies. The power values were logarithmically transformed and paired sample t-tests were done for each voxel and frequency band (1.5-30 Hz). Statistical results were displayed 3-dimensionally on the standard brain template. RESULTS: All subjects experienced positive feelings (relaxed and pleasant) by olfactory stimulation with lavender oil (p<0.01). The LORETA power of theta and alpha band was increased in the dorsolateral and medial frontal areas, predominantly in the posterior cingulate gyri. The alpha LORETA power was also increased in bilateral orbitofrontal regions and the left perisylvian region including the insular cortex. Beta power was increased in the posterior cingulated gyri and mesial temporal region, predominantly on the left side. CONCLUSIONS: These results suggest that olfaction associated with emotional feeling might induce brain electrical power changes not only in the limbic system but also in the neocortex with lateralization to the dominant hemisphere.

The Effect of Resection Extent Upon Postoperative Outcome of Seizures and Memory in Anterior Temporal Lobectomy with Amygdalohippocampectomy / 대한간질학회지

PURPOSE: To investigate the relationship of the resection extent of hippocampus and temporal neocortex with the postsurgical outcome in patients with mesial temporal lobe epilepsy (TLE). METHODS: Sixty-eight patients with TLE underwent brain MRI pre- and post-operatively. They were divided into two groups by seizure outcomes:seizure free group (SF, N=54) and non-seizure free group (NSF, N=14). Patients were classified further according to the post-surgical memory changes:MD group (with postsurgical memory decline, N=15) and NMD group (without postsurgical memory decline, N=16). The hippocampal resection was estimated by subtracting the length of post-surgical hippocampus from the pre-surgical length. The resection of temporal neocortex was measured by comparing the resection lengths on superior, middle, inferior and basal temporal gyri shown on three dimensional brain MRI. RESULTS: The mean extent of hippocampal resection was significantly larger in SF than in NSF (33.2+/-7.5 mm vs. 24.8+/-7.4 mm p=0.001) while that between MD and NMD was not significantly different. The resection extent of temporal neocortex was not significantly different between SF and NSF as well as between MD and NMD, but the resection extent of basal temporal gyrus of left TLE was significantly larger in MD than in NMD. CONCLUSIONS: The hippocampal resection was significantly greater in SF. The overall resection extent of the temporal neocortex did not correlate to the surgical outcomes of seizures or memory although that of the basal temporal gyrus of the left TLE was larger in MD.

Experience of Endovascular Treatment of Distal Posterior Cerebral Artery Aneurysms

OBJECTIVE: Distal posterior cerebral artery(PCA) aneurysms requiring the problematic surgical approaches are rarely encountered. With the development of endovascular treatment, distal PCA aneurysms tend to be treated by endovascular method rather than surgery. We report our experience of distal PCA aneurysms, which were managed mainly by endovascular treatment. METHODS: During the last 5 years, there were five patients harboring distal PCA aneurysms(0.7% among a total 656 intracranial aneurysms). Four patients presented with subarachnoid hemorrhage, while one presented with ipsilateral facial hypesthesia. Four of them were treated by endovascular(Guglielmi detachable coil: GDC) embolization and one was treated by surgical clipping after failure of GDC embolization. RESULTS: Complete obliteration with parent artery encroachment was confirmed in 2 cases. There was one occipital lobe infarction and it resulted in the homonymous quadrantanopsia. In the other case, cerebral infarction did not develop. Incomplete coil embolization was inevitably performed to avoid parent artery occlusion in another two cases. CONCLUSION: Even with the obliteration of the parent artery, distal PCA aneurysms could be treated by use of GDC effectively. Adequate collateral supply to the distal arterial territory seems to contribute to it. Further study needs to be performed to verify this hypothesis.

Multiphasic Perfusion CT in Acute Middle Cerebral Artery Ischemic Stroke: Prediction of Final Infarct Volume and Correlation with Clinical Outcome

OBJECTIVE: To assess the utility of multiphasic perfusion CT in the prediction of final infarct volume, and the relationship between lesion volume revealed by CT imaging and clinical outcome in acute ischemic stroke patients who have not undergone thrombolytic therapy. MATERIALS AND METHODS: Thirty-five patients underwent multiphasic perfusion CT within six hours of stroke onset. After baseline unenhanced helical CT scanning, contrast-enhanced CT scans were obtained 20, 34, 48, and 62 secs after the injection of 90 mL contrast medium at a rate of 3 mL/sec. CT peak and total perfusion maps were obtained from serial CT images, and the initial lesion volumes revealed by CT were compared with final infarct volumes and clinical scores. RESULTS: Overall, the lesion volumes seen on CT peak perfusion maps correlated most strongly with final infarct volumes (R2=0.819, p<0.001, slope of regression line=1.016), but individual data showed that they were less than final infarct volume in 31.4% of patients. In those who showed early clinical improvement (n=6), final infarct volume tended to be overestimated by CT peak perfusion mapping and only on total perfusion maps was there significant correlation between lesion volume and final infarct volume (R2=0.854, p=0.008). The lesion volumes depicted by CT maps showed moderate correlation with baseline clinical scores and clinical outcomes (R=0.445-0.706, p<=0.007). CONCLUSION: CT peak perfusion maps demonstrate strong correlation between lesion volume and final infarct volume, and accurately predict final infarct volume in about two-thirds of the 35 patients. The lesion volume seen on CT maps shows moderate correlation with clinical outcome.

Perfusion MR Imaging: Clinical Utility for the Differential Diagnosis of Various Brain Tumors

OBJECTIVE: To determine the utility of perfusion MR imaging in the differential diagnosis of brain tumors. MATERIALS AND METHODS: Fifty-seven patients with pathologically proven brain tumors (21 high-grade gliomas, 8 low-grade gliomas, 8 lymphomas, 6 hemangioblastomas, 7 metastases, and 7 various other tumors) were included in this study. Relative cerebral blood volume (rCBV) and time-to-peak (TTP) ratios were quantitatively analyzed and the rCBV grade of each tumor was also visually assessed on an rCBV map. RESULTS: The highest rCBV ratios were seen in hemangioblastomas, followed by high-grade gliomas, metastases, low-grade gliomas, and lymphomas. There was no significant difference in TTP ratios between each tumor group (p<0.05). At visual assessment, rCBV was high in 17 (81%) of 21 high-grade gliomas and in 4 (50%) of 8 low-grade gliomas. Hemangioblastomas showed the highest rCBV and lymphomas the lowest. CONCLUSION: Perfusion MR imaging may be helpful in the differentiation of thevarious solid tumors found in the brain, and in assessing the grade of the various glial tumors occurring there.

A Study of Optimal SOAmin for Motor and Language Tasks in Event-related fMRl using Stochastic Design

PURPOSE: The minimum stimulus onset asynchronoy(SOAmin) is one of important experimental parameters for an event-related fMRl experiment designed with the stochastic stimulus. In this study, the most efficient SOAmin is explored for the stronger activation in motor and language tasks with the stimulus designed stochastically. MATERIALS AND METHODS: The event-related fMRl during motor and language tasks were obtained in four normal right-handed subjects. EPI-BOLD sequence is used at 1.5 Tesla MR system for the acquisition of event-related fMRl. For each task the subjects are responded for the stimulus' with 2, 3, 4, and 6 seconds SOAmin. The obtained images are processed with SPM99, and the p value is set as 0.05 for the significant activation detection. The Z value and the number of activated pixels are compared for each task. RESULTS: For the motor task, the primary and supplementary motor areas are activated, and for the language task the consistent activated signals are detected in the Broca's. The activated signal is to be stronger for the shorter SOAmin for both motor and language tasks. At primary motor area, the activated signals is the strongest for 3 seconds SOAmin and for the supplementary motor area the result with 2 seconds SOAmin shows the strongest activation. And the result of language task shows the strongest activation at the 2 seconds SOAmin. CONCLUSION: In the event-related fMRl of motor and language tasks with the stochastically designed stimulus, the 2 or 3 seconds SOAmin is efficient for more activated and clustered activation.