Clinical improvements in temporospatial gait variables after a spinal tap test in individuals with idiopathic normal pressure hydrocephalus.

Idiopathic Normal Pressure Hydrocephalus (iNPH) is a neurological condition that often presents gait disturbance in the early stages of the disease and affects other motor activities. This study investigated changes in temporospatial gait variables after cerebrospinal fluid (CSF) removal using a spinal tap test in individuals with idiopathic normal pressure hydrocephalus (iNPH), and explored if the tap test responders and non-responders could be clinically identified from temporospatial gait variables. Sixty-two individuals with iNPH were recruited from an outpatient clinic, eleven were excluded, leaving a total of 51 who were included in the analysis. Temporospatial gait variables at self-selected speed were recorded at pre- and 24-h post-tap tests which were compared using Paired t-tests, Cohen's d effect size, and percentage change. A previously defined minimal clinical important change (MCIC) for gait speed was used to determine the changes and to classify tap test responders and non-responders. A mixed model ANOVA was used to determine the within-group, between-group, and interaction effects. Comparisons of the data between pre- and post-tap tests showed significant improvements with small to medium effect sizes for left step length, right step time, stride length and time, cadence, and gait speed. Gait speed showed the largest percentage change among temporospatial gait variables. Within-group and interaction effects were found in some variables but no between-group effect was found. Tap test responders showed significant improvements in right step length and time, stride length and time, cadence, and gait speed while non-responders did not. Some individuals with iNPH showed clinically important improvements in temporospatial gait variables after the tap test, particularly in step/stride length and time, cadence, who could be classified by gait speed. However, gait-related balance variables did not change. Therefore, additional treatments should focus on improving such variables.

Relationships between amyloid levels, glucose metabolism, morphologic changes in the brain and clinical status of patients with Alzheimer's disease.

OBJECTIVE: The current study was conducted to improve the understanding of relationships between regional cortical amyloid load, glucose metabolism, cortical morphology (volume), and severity of clinical symptoms in patients with AD, MCI, and age-matched controls. METHODS: To objectivize the radiological evaluation of patients with suspected AD, head-to-head multi-modality imaging studies were conducted using MRI and PET/CT with [18F]FDG and [18F]AV45 for visualization and quantitation of brain morphology, glucose metabolism, and amyloid levels, respectively. A total of 84 subjects was studied, including 33 patients with AD, 31 patients with MCI, and 20 age-matched healthy controls (HC). A new quantitative index was calculated as a ratio of regional SUV of [18F]AV45 (normalized to cerebellar cortex) over the corresponding regional SUV of [18F]FDG, divided by the corresponding regional volume, measured from the co-registered MRI and normalized to the normal age-matched control group (AV45/FDG/NVol index). Relationships between clinical scores (TMSE, ADAS) and AV45/FDG/NVol indices for different structures of the brain in study groups were determined using linear regression analyses. RESULTS: A significant direct linear correlation was observed between the AV45/FDG/NVol index and ADAS-Cog test score and an inverse correlation with TMSE score at baseline and with the degree of changes in ADAS and TMSE scores assessed one year later (disease progression). The observed correlations between AV45/FDG/NVol index and clinical scores were higher than those with MRI-based cortical volumes, FDG SUV, or cerebellum-normalized AV45 SUV alone. CONCLUSIONS: Current study demonstrated that AV45/FDG/NVol index mapping of the brain is a novel quantitative molecular imaging biomarker that correlates with clinical neurocognitive status and may facilitate more accurate diagnosis, staging, and prognosis of AD. Additional larger scale clinical studies are required to further evaluate the efficacy of this new quantitative index as a diagnostic and prognostic biomarker of AD as well as for the evaluation of safety and efficacy of novel agents undergoing clinical trials for therapy of AD.

Comparison of High Resolution T2W and Gd-T1W of MRI Internal Acoustic Canal in Sensorineural Hearing Loss.

Objective: To evaluate the concordance of high resolution T2-weighted (HR-T2W) and Gd-T1W for mass detection in internal acoustic canal (IAC) or cochlear in sensorineural hearing loss (SNHL). Material and Method: The retrospective study of patients with SNHL undergoing magnetic resonance imaging (MRI) IAC protocol was performed. HR-T2W and Gd-T1W were separately reviewed for any mass in IAC or cochlear. Results: One hundred eight cases were available for evaluation with 43 males and 65 females (mean age of 56.04 years old; range 15 to 86 years old). Symptoms of SNHL on right side were 39 cases (36.1%), left side 39 cases (36.1%), both sides 15 cases (13.9%), and asymmetric SNHL 15 cases (13.9%). Twenty two (20.4%) cases had mass in IAC and/or cochlear demonstrated on both HR-T2W and Gd-T1W. No discrepancy of abnormality detection between both pulse sequences was found. Conclusion: HR-T2W was as accurate as Gd-T1W in detecting mass in IAC and cochlear in patients with SNHL. Screening with HR-T2W could be used with confidence and might be reasonable to reducing cost of the MRI study in appropriate setting of patients presenting with SNHL.

Comparison of High Resolution T2W and Gd-T1W of MRI Internal Acoustic Canal in Sensorineural Hearing Loss.

Objective: To evaluate the concordance of high resolution T2-weighted (HR-T2W) and Gd-T1W for mass detection in internal acoustic canal (IAC) or cochlear in sensorineural hearing loss (SNHL). Material and Method: The retrospective study of patients with SNHL undergoing magnetic resonance imaging (MRI) IAC protocol was performed. HR-T2W and Gd-T1W were separately reviewed for any mass in IAC or cochlear. Results: One hundred eight cases were available for evaluation with 43 males and 65 females (mean age of 56.04 years old; range 15 to 86 years old). Symptoms of SNHL on right side were 39 cases (36.1%), left side 39 cases (36.1%), both sides 15 cases (13.9%), and asymmetric SNHL 15 cases (13.9%). Twenty two (20.4%) cases had mass in IAC and/or cochlear demonstrated on both HR-T2W and Gd-T1W. No discrepancy of abnormality detection between both pulse sequences was found. Conclusion: HR-T2W was as accurate as Gd-T1W in detecting mass in IAC and cochlear in patients with SNHL. Screening with HR-T2W could be used with confidence and might be reasonable to reducing cost of the MRI study in appropriate setting of patients presenting with SNHL.

Feasibility Study of Language Lateralization using Thai Version of Language Paradigm for Functional MRI in Clinical Service.

Objective: To evaluate the concordance of language lateralization between functional magnetic resonance imaging (fMRI) using Thai version of language paradigm and Wada test or awake surgery with direct cortical brain stimulation (DCS). Material and Method: Retrospective study of thirteen patients (3 males and 10 females with mean age of 33.9 years old) with epilepsy (7 cases) or brain tumor (6 cases) was performed. Every patient underwent both fMRI (word generation, verb generation, naming picture, and sentence completion tasks) and Wada test or awake surgery with DCS (defined as the gold standard). The lateralization index (LI) of fMRI was automatically calculated by using the LI-toolbox on SPM8. The hemispheric lateralization was also evaluated visually. The concordance between fMRI and gold standard were analyzed. Results: The concordance between the lateralization of fMRI by visual assessment and gold standard was 92.3%. Concordance between the calculated LI by fMRI and gold standard was varied along with the task and regional calculation method. The concordance was good in all tasks (except for naming picture task) when using calculated LI from frontal or whole brain excluded cerebellum and occipital lobe (range 76.92 to 88.98% and 76.92 to 92.31%, respectively). Conclusion: There was good concordance between fMRI and gold standard. Regional calculation from frontal lobes and whole brain excluded cerebellum and occipital lobes gave the best results. The results supported feasibility to use the fMRI with Thai language paradigm as an alternative way to determine the language dominant hemisphere in Thai patients. In case of language dominant hemisphere is unclear, further invasive investigation of language mapping such as Wada test or DCS is crucial.

Computerized Tomographic Angiography for Detection of Cerebral Vasospasm after Ruptured Intracranial Aneurysm.

OBJECTIVE: Digital subtraction angiography (DSA) is the gold standard to diagnose cerebral vasospasm but it is usually not available due to lack of expertise and proper equipment. The present study aimed to compare the diagnostic accuracy of brain computerized tomographic angiography (CTA) in detecting cerebral vasospasm after intracranial aneurysmal rupture. MATERIAL AND METHOD: Between January 2011 and October 2014, 20 patients who were suspected of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) were prospectively enrolled. All patients underwent brain CTA andDSA within 24 hours after clinical onset ofvasospasm. Separate reviewers independently reviewed the CTA and DSA. RESULTS: Twenty patients were enrolled, including 7 males and 13 females. The patient characteristics did not have any relationship to the incidence of cerebral vasospasm. The CTA finding of vasospasm was well correlated to the DSA finding (Kappa 0.793). Diagnostic accuracy and false negative of the CTA were 90% and 5%, respectively. Sensitivity of the CTA was 94% and specificity was 100%. Positive predictive value ofthe CTA was 100% and negative predictive value was 66%. The vessels that showed the most correlation between the CTA and DSA findings were left A1 (Kappa 0.684) and left A2 (Kappa 0.663) segments of anterior cerebral artery, and left M1 (Kappa 0.503) segment of middle cerebral artery. Both CTA and DSA can detect mild vasospasm (< 50% luminal stenosis) located proximal to the circle of Willis. CONCLUSION: Compared to the DSA, the CTA can be used for detecting cerebral vasospasm in patients with ruptured intracranial aneurysms with high sensitivity, specificity, and diagnostic accuracy.

Diagnostic performance of advanced MRI in differentiating high-grade from low-grade gliomas in a setting of routine service.

OBJECTIVE: To evaluate the usefulness of advanced MRI techniques in differentiating high-grade (HGG) from low-grade gliomas (LGG). MATERIAL AND METHOD: Sixty-four patients with suspected gliomas were prospectively evaluated by conventional and advanced MRI studies including MR spectroscopy (MRS), diffusion tensor imagining (DTI), and dynamic susceptibility contrast (DSC) MRI. The parametric measurements of metabolic profile, cerebral blood volume, flow (CBV, CBF), apparent diffusion coefficient (ADC), fractional anisotropy, and their ratios by internal normalization were analyzed to differentiate LGG from HGG. Histopathologic findings were used as the gold standard. RESULTS: Forty-three cases with pathologically-proven gliomas were included The best discriminating features between HGG and LGG were CBV and CBF of the solid tumoral region (p < 0.05) whereas the minADC/corpus callosum ratio for DTI and the ratio of Cho/Cr for MRS of the solid tumoral region provided the best diagnostic performance (p < 0.05). With a predetermined threshold for each parametric measurement, the combination of all advanced MRI modalities was associated with the best accuracy whereas the combination of DSC MRI and MRS provided the highest specificity. When all parametric measurements were positive, the probability of HGG was 0.889. CONCLUSION: Comprehensive advanced MRI studies provided better diagnostic performance than using conventional MRI alone in the evaluation of gliomas.

Diagnostic performance of perfusion MRI in differentiating low-grade and high-grade gliomas: advanced MRI in glioma, A Siriraj project.

BACKGROUND: To determine the usefulness of the perfusion MRI technique at Siriraj Hospital for differentiating between high- and low-grade gliomas by using pathological results as the gold standard. MATERIAL AND METHOD: The authors prospectively investigated 64 consecutive patients who were suspected as cerebral glioma from prior conventional imaging. Cerebral perfusion study was achieved during the first pass of a bolus of gadolinium-based contrast agent. All post-processing MRI images were interpreted by two board-certified neuroradiologists (more than 10-year-experience), one radiology resident and one well-trained technician, who separately performed and blinded from the pathological results. RESULTS: Forty-four patients diagnosed as glioma were included in this study. There were 26 cases of high-grade and 18 cases of low-grade gliomas. The cerebral blood volume and flow and its ratios had a strong association with the grade of glioma. The areas under the ROC curve for CB K CBVratio (rCBV), CBF and CBF ratio (rCBF) are 0.778, 0.769, 0.769, and 0.772, respectively. On the basis of equal misclassification rates, a cutoff value of 6.15 for CBV (sensitivity, 81.5%; specificity, 64.7%), a cutoff value of 2.38 for the rCBV (sensitivity, 88.9%; specificity, 64.7%), a cutoff value of 0.66 for CBF (sensitivity 81.5%; specificity 70.6%), and a cutoff value of 2.6 for the rCBF (sensitivity, 85.2%; specificity, 70.60%) best discriminated the high and low-grade gliomas. CONCLUSION: Preoperative radiologic grading of gliomas based on conventional MR imaging is sometimes unreliable. The cerebral perfusion measurements can significantly improve the sensitivity and predictive values of radiologic glioma grading. The rCBV measurement is the best parameter for tumor grading due to the highest sensitivity.

Value of diffusion tensor imaging in differentiating high-grade from low-grade gliomas.

OBJECTIVE: To determine the usefulness of diffusion tensor imaging (DTI) in differentiating high-grade glioma (HGG) from low-grade glioma (LGG). MATERIAL AND METHOD: Patients with cerebral gliomas underwent conventional MRI and DTI before surgery. All proven pathologies were classified into two groups, i.e. LGG and HGG. The authors measured fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values in region of interest (ROI) including solid tumoral region, necrotic region, peritumoral edema, contralateral normal appearing white matter (NAWM) and normal corpus callosum as well as calculated ADC ratios. Pairwise comparisons were performed by using the t-test. The ROC curves of imaging parameters were employed to determine the best parameter for differentiating the two entities. RESULTS: Forty-three patients with cerebral gliomas, 17 with LGG and 26 with HGG, no statistical significant difference between LGG and HGG using mean FA values in each ROI. The ADC and minimal ADC values of solid tumoral region and peritumoral edema, the ADC and minimal ADC ratios of solid tumoral region are statistical significant to differentiate HGG from LGG, p < 0.05. The ratio ADC solid tumoral region to normal corpus callosum had highest predictive accuracy to differentiate the two entities with AUC of 0.74. CONCLUSION: The ADC value, minimal ADC value, and ADC ratios of solid tumoral region appeared to be useful for differentiating HGG from LGG.

Ischemic cerebrovascular disease and calcified intracranial vertebrobasilar artery: A case-control study by using cranial CT.

OBJECTIVE: To evaluate the association of intracranial vertebrobasilar (VB) artery calcification and ischemic cerebrovascular disease of the posterior circulation. MATERIAL AND METHOD: A cross-sectional, retrospective, case-control study was performed in 198 patients with cranial CT Presence of the posterior fossa infarction was disclosed in 104 patients of the case group. Absence of the posterior fossa infarction in 94 patients were defined as a control group. They were age and sex matched. Circumferential and thickness of calcification was graded for the intracranial vertebral and basilar arteries. Association between vascular wall calcification and posterior fossa infarction was analyzed. RESULTS: No statistically significant relationship between the presence of VB calcification and posterior fossa infarction was found (p = 0.08, OR = 1.75, 95% CI = 0.94-3.26). In subgroup analysis, by re-classifying occipital lobe and thalamus as areas supplied by VB system, there was a statistically significant relationship between the VB calcification and infarction (p = 0.02, OR = 2.08, 95% CI = 1.10-3.94). No relationship between degree of calcification and the area of infarction was observed. CONCLUSION: The present study showed no significant relationship between the VB artery calcification and ischemic infarction of cerebellum and brainstem, but a significant relationship between VBA calcification and infarction in the end territory of VBA supply.

Vertebral body compression fracture: discriminating benign from malignant causes by diffusion-weighted MR imaging and apparent diffusion coefficient value.

OBJECTIVE: To evaluate the diagnostic performance of apparent diffusion coefficient (ADC) value in discriminating benign from malignant vertebral compression fracture. MATERIAL AND METHOD: 22 symptomatic patients with compression fracture of vertebra referred for conventional MRI spines during January 2009-March 2010 underwent additional diffusion weighted MR techniques. Evaluation of diffusion weighted MR imaging and quantified ADC value from reconstructed ADC map were performed. The accuracy, sensitivity, specificity, positive predictive value and negative predictive value of apparent diffusion coefficient (ADC) value were calculated. RESULTS: A total of 39 vertebral fractures; 7 malignant compression fractures and 32 benign compression fractures were evaluated. The difference between ADC values of malignant, benign compression fracture and normal vertebrae were statistically significant (p < 0.0001). The accuracy, sensitivity and specificity were 89.7%, 85.7% and 90.6% respectively with the ADC threshold of 0.89 to discriminate malignancy. CONCLUSION: The ADC promises to be an effective implement for characterization of vertebral body compression fracture in differentiating benign and malignant compression fractures.

MRI study of intracranial hydrodynamics and ventriculoperitoneal shunt responsiveness in patient with normal pressure hydrocephalus.

OBJECTIVE: To determine the predictor for shunt responsive cases in patient with normal pressure hydrocephalus (NPH) by means of magnetic resonance imaging (MRI) cerebrospinal fluid (CSF) flow study at Siriraj hospital. MATERIAL AND METHOD: The retrospective study was performed in patients suspected NPH and underwent MRI CSF flow measurement. 2D-phase contrast technique (Achieva, 3 Tesla Philips system) was used as CSF flow analysis. The preoperative and postoperative clinical outcomes were collected and analyzed to determine predictive value of MRI CSF flow measurement in shunt responsive patients. RESULTS: Between 2006 and 2011, twenty NPH patients underwent MRI CSF flow study and were treated by ventriculoperitoneal shunt placement. Fourteen of 20 cases had improved, at least in gait score. Of these, 10 were defined as significant responsive group for overall improvement of outcome (sum of iNPHGS > or =3). The mean velocity of the CSF flow through the aqueduct of Sylvius was significant difference between shunt-responsive and non- responsive groups (p < 0.05). The peak velocity was a significant difference between gait responsive and non-responsive groups (p < 0.05). Using a mean velocity threshold 26 mm/sec to identify the significant responsive group, the sensitivity is 50%, specificity 83.3%, positive predictive value 87.5%, and accuracy 70%. In order to identify the gait responsive group by using a threshold of peak velocity 70 mm/sec, the sensitivity was 60%, specificity 83.3%, positive predictive value 81.5%, and accuracy 60%. CONCLUSION: Using available commercial software in the authors'institute, the mean velocity as well as the peak velocity was a specific value that predicted significant shunt responsiveness in NPH patients.

Evidence of vascular compromise over the visual cortex during migrainous headache: a case report with MRI study.

The objective of the present study was to demonstrate MRI evidence of vascular compromise as seen in a 17-year-old female presenting with migrainous headache. The patient had been experiencing migrainous headache 2 days ago. She had visual auras lasting for a few hours before the attack. Upon meeting with her physician she indicated symptoms of left sided numbness during the headache. No neurological deficit was detected when the first MRI was performed, and all of her symptoms resolved within 4 days of the attack. The MRI study showed a focal area of restricted diffusion at the right visual cortex. A short segment of vascular enhancement was noted on the surface of the affected gyrus. MRS showed a normal N-acetyl aspartate, choline, and creatine with no elevation of lactate. A follow-up MRI study 5 months later showed normal finding with no residual lesion. The authors concluded that the abnormality on the first MRI was the ischemic insult of the ictal visual cortex which was transient during the migraine attack. The pathophysiology was more likely from reversible focal venous congestion.

Diagnostic accuracy of perfusion CT in differentiating brain abscess from necrotic tumor.

OBJECTIVE: To evaluate the diagnostic accuracy of perfusion computed tomography (CTP) in differentiating between brain abscess and necrotic tumor. MATERIAL AND METHOD: Prospective study was performed in patients suspected of a space taking lesion in the brain. CTP was done at the suspected levels and post-processing measurement of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and permeability surface index (PS) were evaluated at ring enhanced area, central non-enhanced area, edema and contralateral normal brain. RESULTS: Seventeen patients with 21 lesions were studied. Of the 21 lesions, 12 were abscess and nine were tumors. By comparing means, only MTT at the ring enhanced area showed statistically significant difference between brain abscess and tumor (p = 0.009, 95% CI = 1.403 to 4.900). When ratio of CBV, CBF and MTT of the ring enhanced area and contralateral normal brain were analyzed (CBVr, CBFr, MTTr respectively), there were significant differences of CBVr and CBFr between the two groups (p = 0.003, 95% CI = -4.266 to -1.051 and p = 0.006, 95% CI = -9.934 to -1.969 respectively). With the threshold of CBVr more than or equal to 1.5 and CBFr more than or equal to 1, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for diagnosis of tumor were 100%, 75%, 75%, 100%, and 85.7% respectively. CONCLUSION: The CTP was shown to be useful in differentiating brain abscess from tumor. With CBVr less than 1.5, tumor can be excluded.

Reliability study of white matter rating scale for the dementia and disability in Thai Elderly Project.

OBJECTIVE: To study the reliability of white matter rating scale on magnetic resonance imaging (MRI) of elderly patients in the urban community of Bangkok. MATERIAL AND METHOD: One hundred elderly with clinical diagnosis of cognitive impairment in the urban community around Siriraj Hospital underwent cranial MRI according to the Dementia and Disability in Thai Elderly Project. The axial T1wi, T2wi, and fluid attenuated inversion recovery (FLAIR) were separately assessed by two neuroradiologists. The assessment included white matter change by using Scheltens' rating scale, atrophy, and evidence of infarction. The inter-rater agreements were analyzed. RESULTS: The inter-rater agreement of periventricular hyperintensities, white matter, basal ganglion and infratentorial foci of hyperintensities were very good (ICC = 0.89-0.98). The agreement was good for central atrophy (Kw = 0.66) and moderate for cortical atrophy (Kw = 0.49). The silent infarction was found in the study population and divided into cortical (15%), subcortical (26%), brainstem (3%), and infratentorial infarction (8%). CONCLUSION: White matter hyperintensities was an important radiological criteria for diagnosis of vascular dementia. Appropriate rating scale is necessary especially in research study. The authors found that Scheltens rating scale needed some training and slightly time consuming at the beginning but was a good reliable tool.

Radiographic chest findings and clinical correlations in leptospirosis.

OBJECTIVE: To determine the clinical presentations, radiographic chest findings, and their correlation in patients with leptospirosis. DESIGN: A cross sectional study. SETTING: Between July 2001- December 2002 at 3 hospitals in North Eastern Thailand. MATERIAL AND METHOD: Two hundred and forty patients with laboratory confirmed leptospirosis. RESULTS: Two hundred and nine (87.1%) patients were males. The mean age was 37.53 years (range 13-76). The median duration of fever was 3 days (range 1-13). Overall, 154 patients (64.2%) had respiratory symptoms and 26 (10.8%) patients had hemoptysis. Jaundice was detected in 76 (31.7%) patients, hypotension in 50 (20.8%), renal dysfunction in 80 (30%), and multiorgan dysfunction in 62 (25.8%) on admission. One hundred and fifty-four (64.17%) patients had abnormal chest radiographs on admission (classified as cardiovascular, pulmonary, and mixed cardio-pulmonary involvement in 40 (25.97%), 41 (26.62%), and 73 (47.4%) patients, respectively). Jaundice was significantly associated with the likelihood of having abnormal chest radiography on admission. Air- space nodules detected on the chest radiograph were significantly more common in patients with renal dysfunction and patients who required mechanical ventilation. CONCLUSION: Pulmonary and cardiovascular involvements are common in leptospirosis. Air-space nodules detected by chest radiography may indicate severe leptospirosis.

MRI of multiple sclerosis in Thai patients.

OBJECTIVE: Evaluate the MRI findings of multiple sclerosis (MS) in Thai patients and compare these with the McDonald criteria for dissemination in space. MATERIAL AND METHOD: A retrospective study was performed by reviewing clinical and MRI records of patients attending MS clinic at Siriraj Hospital. Only patients with complete clinical and MRI data were included in the present study. RESULTS: There were 25 patients included in the study. Twenty-four patients were females and 1 was male. The mean age was 35.24 years old (range 16-50). The disease duration was 1 month to 17 years after the onset. Twenty-three patients were diagnosed as relapsing-remitting MS, one as possible MS and one as clinical isolated syndrome. Analysis for CSF oligoclonal bands was performed in 22 cases with positive results in 6 cases (27.3%). The sites of involvement were optic neuritis (16 cases), spinal cord (14 cases), and brain (9 cases). Seventeen cases had MRI study at the early presentations, and 8 cases during subsequent relapses. In the 9 cases with brain symptoms, all had positive brain MRI. Ten cases (58.8%) had infratentorial lesions mostly found at the medulla. Most T2 lesions were found at juxtacortical and periventricular regions. Five in 9 cases (55.6%) with periventricular lesions had lesions not less than 3 mm and at least 3 lesions were found. There were 6 cases (35.3%) with, at least, nine T2 lesions. Most of the T2 lesions were oval shaped. Seven cases (41.2%) had black hole lesions. Three cases (17.6%) had gadolinium enhanced lesions. Thirteen of 15 available spinal MRI were abnormal. The locations of the lesions were cervical (6), thoracic (4) and cervicothoracic (3) levels. The number of T2 lesions was one in 8 cases and more than one in 5 cases. The length of each lesion varied: less than 1 vertebral segment (5 cases) and 2 or more vertebral segments (8 cases). Swelling of the cord was found in 3 cases and atrophy in 7 cases. The lesions occupied the whole cross-sectional cord in 6 cases and center of the cord in 7 cases. The gadolinium enhancement was found in 6 cases with a patchy pattern in 5 cases and mixed ring and patchy patterns in 1 case. There were totally 6 cases (24%) that fulfilled the McDonald MRI criteria for dissemination in space. CONCLUSION: The MRI findings in Thai MS have distinct features from the Western reports. Re-evaluation of McDonald criteria for the Eastern countries is needed.