Cord Topographical Anatomy and its Role in Evaluating Intramedullary Lesions.

Intramedullary spinal lesions present a wide differential diagnosis including infectious, inflammatory, traumatic, ischemic, benign, or malignant neoplastic etiologies. Using knowledge of anatomy and physiology within the spinal cord, many similar appearing entities can be parsed into a prioritized differential. The purpose of this article is to review anatomy and pathophysiology of the spinal cord, with subsequent discussion of how this knowledge can be used to differentiate several similar appearing intramedullary pathologic processes. Discussion includes the pathophysiology, imaging findings, and clinical pearls of several intramural lesions including infarct, demyelinating lesions, traumatic injury, neoplasm, vascular malformation, and metabolic processes such as subacute combined degeneration.

Perfusion and Diffusion Abnormalities of Multiple Sclerosis Lesions and Relevance of Classified Lesions to Disease Status.

OBJECTIVE: Hemodynamic abnormality and disruption of white matter (WM) integrity are significant components in the pathophysiology of multiple sclerosis (MS) lesions. However, the roles of stratified lesions with distinct degrees of hemodynamic and structural injury in disease states remain to be explored. We tested the hypothesis that hemodynamic and structural impairment, as assessed by cerebral blood volume (CBV) and fractional anisotropy (FA), respectively, characterizes the extent of tissue injury, and the load of lesion with substantial tissue destruction would reflect the disease status and therefore, would be related to clinical disability. METHODS: Seven relapsing-remitting MS patients and seven healthy controls underwent perfusion, diffusion and conventional MRI scans. Based on T2-FLAIR and T1-weighted image, WM plaques were classified. After image coregistration, values of CBV and FA were estimated in three distinct lesion types (active, T1-hypointense and T1-isointense lesion) and compared with those obtained in WM from controls. A total of 1135 lesions were evaluated. Brain volumetric measurement and correlative analysis between brain atrophy, lesion volume and clinical disability were also performed. RESULTS: Compared with normal WM, significantly reduced CBV and FA were present in the T1-hypointense lesion, while insignificant changes in both parameters were exhibited in the T1-isointense lesion. However, increased CBV but significantly decreased FA was detected in the active lesion. A close spatial relationship between active and T1-hypointense lesion was observed. Lesion load represented by T1-hypointense plus active lesion volume significantly correlated with brain atrophy, which, in turn, significantly correlated with the severity of clinical disability. CONCLUSION: A distinct combination of CBV and FA characterizes the status of a specific lesion type. A severe structural impairment does not solely occur in the T1-hypointense lesion, but is also associated with the active lesion. The burden of the lesion with extensive structural damage provides an image index, indicative of disease status.

Proof of concept study: relating infarct location to stroke disability in the NINDS rt-PA trial.

BACKGROUND: The summed Alberta Stroke Program Early CT Score (ASPECTS) for noncontrast head CT scan represents the extent of early brain ischemia and has been shown to be useful for predicting stroke outcome. The ASPECTS template contains information on anatomical location which so far has not been used in analysis. This may not have been done because adjacent brain regions have related functions and share vascular territory. The task of relating neurological deficit to infarct localization requires brain imaging analysis tools which deal with this issue of relatedness or collinearity. We have previously used partial least squares with penalized logistic regression (PLR) to handle this problem of collinearity. A disadvantage of this method is that it cannot be performed at the bedside and requires processing and analysis in the imaging laboratory. PLR is a simpler analytic tool compared to partial least squares with PLR for dealing with this issue of relatedness (collinearity). It provides results in terms of ß coefficients related to specific infarct locations in a manner that is intuitively understood by clinicians. In this exploratory analysis, we hypothesized that infarct location as represented by the individual ASPECTS region may be independently related to disability. METHODS: ASPECTS from CT scans of patients in the National Institute of Neurological Disorders and Stroke (NINDS) recombinant tissue plasminogen activator (rt-PA) Study were obtained. Due to the collinearity between the ASPECTS regions, we used PLR to determine the independent associations of exposures (rt-PA), demographic variables (age and sex), and imaging (ASPECTS location) with poor outcome as defined by a modified Rankin Scale score of >2. RESULTS: In 607/624 subjects with ASPECTS readings, variables significantly associated with poor outcome included: interactions between ASPECTS M6 region (primary motor cortex/parietal lobe) and age (p = 0.004), lentiform nucleus and age (p = 0.007), and blood sugar level and age (p = 0.01). The model suggested that older age or involvement of either M6 or lentiform nucleus slightly increased the odds of disability. However, the predominant effect was driven by rt-PA which reduced the odds of poor disability (OR 0.597, 95% CI 0.425-0.838, p = 0.003). This may potentially explain why certain patients have smaller gains from rt-PA treatments. CONCLUSION: At an older age, specific infarct locations may be associated with a poorer outcome in this exploratory re-analysis of the NINDS rt-PA Study.

Tumor vascular leakiness and blood volume estimates in oligodendrogliomas using perfusion CT: an analysis of perfusion parameters helping further characterize genetic subtypes as well as differentiate from astroglial tumors.

The purpose of this study was to determine the usefulness of perfusion CT (PCT) parameters particularly blood volume and neovascular permeability estimates (permeability surface area-product, PS) in the evaluation of oligodendrogliomas (OG), correlation with genetic subtypes of OGs (with or without loss of heterozygosity/LOH on 1p/19q) as well as comparison of perfusion parameters of OGs with astroglial tumors. Pre-operative PCT done in 21 patients with OGs was retrospectively correlated with our previously published PCT data for 32 patients with astroglial neoplasms (Jain R et al., AJNR Am J Neuroradiol 29:694-700, 2008). All OGs were also analyzed for genetic subtypes of with or without LOH. PCT parameters PS and cerebral blood volume (CBV) were obtained for the entire lesion and a statistical analysis done to correlate various histopathological variants. Low grade OGs (n = 13) showed slightly lower CBV (1.42 vs. 1.72 ml/100 g; P value 0.391) and PS (0.56 vs. 0.95 ml/100 g/min; P value 0.099) as compared to high grade OGs (n = 8), though not statistically significant. LOH positive OGs (n = 13) showed higher mean CBV (1.59 vs. 1.45; P value 0.712) and slightly lower PS (0.68 vs. 0.75; P value 0.718) as compared to LOH negative OGs (n = 8), although not statistically significant. Low grade OGs (n = 13) showed higher mean CBV 1.42 ml/100 g as compared to low grade astroglial tumors (n = 8) 0.95 ml/100 g (P value = 0.08), however no statistically significant difference was noted for PS (0.56 vs. 0.52 ml/100 g/min, P value 0.695). Statistically significant differences were observed in CBV and PS values of high grade OGs and high grade astroglial tumors with the high grade glial tumors showing higher mean CBV (2.79 vs. 1.72; P value 0.03) as well as higher PS (2.37 vs. 0.95; P value < 0.01), however this difference was not significant if only comparing grade III OGs with grade III astroglial tumors. PCT perfusion parameters including PS values do not help grade OGs despite showing a trend for higher CBV and PS in higher grade OGs. Similarly LOH positive OGs also showed slightly higher CBV, but again failed to reach any statistically significant level. Low grade OGs showed slightly higher CBV as compared to low grade astroglial tumors, whereas higher grade OGs showed significantly lower PS values as compared to higher grade astroglial tumors despite showing high CBV.

Predicting survival in glioblastomas using diffusion tensor imaging metrics.

PURPOSE: To retrospectively correlate various diffusion tensor imaging (DTI) metrics in patients with glioblastoma multiforme (GBM) with patient survival analysis and also degree of tumor proliferation index determined histologically. MATERIALS AND METHODS: Thirty-four patients with histologically confirmed treatment naive GBMs underwent DTI on a 3.0 Tesla (T) scanner. Region-of-interest was placed on the whole lesion including the enhancing as well as nonenhancing component of the lesion to determine the various DTI metrics. Kaplan-Meier estimates and Cox proportional hazards regression methods were used to assess the relationship of DTI metrics (minimum and mean values) and Ki-67 with progression free survival (PFS). To study the relationship between DTI metrics and Ki-67, Pearson's correlation coefficient was computed. RESULTS: Univariate analysis showed that patients with fractional anisotropy (FA)(mean) ≤ 0.2, apparent diffusion coefficient (ADC)(min) ≤ 0.6, planar anisotropy (CP)(min) ≤ 0.002, spherical anisotropy (CS)(mean) > 0.68 and Ki-67 > 0.3 had lower PFS rate. The multivariate analysis demonstrated that only CP(min) was the best predictor of survival in these patients, after adjusting for age, Karnofsky performance scale and extent of resection. No significant correlation between DTI metrics and Ki-67 were observed. CONCLUSION: DTI metrics can be used as a sensitive and early indicator for PFS in patients with glioblastomas. This could be useful for treatment planning as high-grade gliomas with lower ADC(min), FA(mean), CP(min), and higher CS(mean) values may be treated more aggressively.

Periictal diffusion abnormalities of the thalamus in partial status epilepticus.

PURPOSE: To identify and describe thalamic dysfunction in patients with temporal as well as extratemporal status epilepticus (SE) and to also analyze the specific clinical, radiological, and electroencephalography (EEG) characteristics of patients with acute thalamic involvement. METHODS: We retrospectively identified patients who presented with clinical and electrographic evidence of partial SE and had thalamic abnormalities on diffusion-weighted imaging (DWI) within 5 days of documentation of lateralized epileptiform discharges (group 1). The spatial and temporal characteristics of the periodic lateralized epileptiform discharges (PLEDs) and the recorded electrographic seizures were analyzed and correlated with magnetic resonance imaging (MRI)-DWI hyperintense lesions. The findings of group 1 patients were compared with those of patients with partial SE without thalamic abnormalities on DWI (group 2). RESULTS: The two groups were similar with regard to clinical presentation and morphology of epileptiform discharges. Group 1 patients had thalamic hyperintense lesions on DWI that appeared in the region of the pulvinar nucleus, ipsilateral to the epileptiform activity. Statistically significant relationship was noted between the presence of thalamic lesions and ipsilateral cortical laminar involvement (p = 0.039) as well as seizure origin in the posterior quadrants (p = 0.038). A trend towards PLEDs originating in the posterior quadrants was also noted (p = 0.077). DISCUSSION: Thalamic DWI hyperintense lesions may be observed after prolonged partial SE and are likely the result of excessive activity in thalamic nuclei having reciprocal connections with the involved cortex. The thalamus likely participates in the evolution and propagation of partial seizures in SE.

First-pass perfusion computed tomography: initial experience in differentiating recurrent brain tumors from radiation effects and radiation necrosis.

OBJECTIVE: To differentiate recurrent tumors from radiation effects and necrosis in patients with irradiated brain tumors using perfusion computed tomographic (PCT) imaging. METHODS: Twenty-two patients with previously treated brain tumors who showed recurrent or progressive enhancing lesions on follow-up magnetic resonance imaging scans and had a histopathological diagnosis underwent first-pass PCT imaging (26 PCT imaging examinations). Another eight patients with treatment-naïve, high-grade tumors (control group) also underwent PCT assessment. Perfusion maps of cerebral blood volume, cerebral blood flow, and mean transit time were generated at an Advantage Windows workstation using the CT perfusion 3.0 software (General Electric Medical Systems, Milwaukee, WI). Normalized ratios (normalized to normal white matter) of these perfusion parameters (normalized cerebral blood volume [nCBV], normalized cerebral blood flow [nCBF], and normalized mean transit time [nMTT]) were used for final analysis. RESULTS: Fourteen patients were diagnosed with recurrent tumor, and eight patients had radiation necrosis. There was a statistically significant difference between the two groups, with the recurrent tumor group showing higher mean nCBV (2.65 versus 1.10) and nCBF (2.73 versus 1.08) and shorter nMTT (0.71 versus 1.58) compared with the radiation necrosis group. For nCBV, a cutoff point of 1.65 was found to have a sensitivity of 83.3% and a specificity of 100% to diagnose recurrent tumor and radiation necrosis. Similar sensitivity and specificity were 94.4 and 87.5%, respectively, for nCBF with a cutoff point of 1.28 and 94.4 and 75%, respectively, for nMTT with a cutoff point of 1.44 to diagnose recurrent tumor and radiation necrosis. CONCLUSION: PCT may aid in differentiating recurrent tumors from radiation necrosis on the basis of various perfusion parameters. Recurrent tumors show higher nCBV and nCBF and lower nMTT compared with radiation necrosis.

Spinal cord pilomyxoid astrocytoma: an unusual tumor.

We present the imaging findings of a case of spinal pilomyxoid astrocytoma in a 29-year-old woman with history of neck and back pain and weakness of bilateral upper extremities. A contrast-enhanced magnetic resonance (MR) imaging study revealed an extensive intradural extramedullary lesion occupying most of the thecal sac extending from mid cervical up to the lumbosacral region with extensive contrast enhancement. Spinal pilomyxoid astrocytoma is rare with only three reported cases in pediatric population in the literature. This report illustrates the MR findings of an unusual case of intradural extramedullary spinal pilomyxoid tumor in an adult patient.

Multiparametric iterative self-organizing data analysis of ischemic lesions using pre- or post-Gd T1 MRI.

BACKGROUND: The purpose of this work was to evaluate effects of Gd-diethylenetriaminepentacetic acid (DTPA) injection on T(1)-weighted images of stroke and lesion segmentation and characterization results generated by our multiparametric iterative self-organizing data (ISODATA) method. The post-Gd image incorporates vasculature information into the analysis. METHODS: Either a pre-Gd T(1)-weighted image (T1WI) or a post-Gd T1WI was used along with diffusion-, T(2)- and proton-density-weighted images in the analysis. ISODATA is a data-driven method that segments and characterizes tissue damage in stroke using multiparametric MRI. RESULTS: Experimental results in both animal and human studies showed that the use of post-Gd T1WI modified the segmentation and characterization results on the periphery of the lesion. The peripheral region that changes with Gd-DTPA has a higher permeability compared to the rest of the lesion. Either of the data sets (including pre- or post-Gd T1WI) was used to estimate the tissue recovery and generated consistent results. CONCLUSIONS: This study shows that our multiparametric ISODATA approach consistently identifies and characterizes the core of the ischemic lesion. It also shows that the inclusion of post-Gd T1WI results in the segmentation and characterization of the lesion periphery if it has a higher permeability compared to the rest of the lesion. Finally, it confirms that the multiparametric ISODATA MRI characterizes tissue damage and recovery in stroke.

Importance of early ischemic computed tomography changes using ASPECTS in NINDS rtPA Stroke Study.

BACKGROUND AND PURPOSE: The importance of early ischemic change (EIC) on baseline computed tomography (CT) in the decision to thrombolyze the patient with acute ischemic stroke has been controversial. ASPECTS is a semiquantitative scale that scores the extent of EIC within the middle cerebral artery territory. We examined whether ASPECTS could be a treatment modifier by systematically reviewing the CT scans in the NINDS rtPA Stroke Study. METHODS: Six hundred eight of the 624 CT scans were available and of sufficient quality. One of 2 teams (n=3 each) of expert ASPECTS readers evaluated each scan for an ASPECTS value using a consensus score approach. Each team was blind to all clinical information except symptom side and blind to follow-up imaging and outcome information. ASPECTS values were stratified before analysis. Multivariable logistic regression was used to determine if an ASPECTS by treatment interaction existed on treatment response, outcome, and intracerebral hemorrhage risk. RESULTS: A total of 57.2% (348 of 608) of scans showed EIC with an ASPECTS <10. ASPECTS dichotomized into 8 to 10 and <8 did not have a treatment-modifying effect on good outcome but showed a trend to lower mortality at 90 days with tPA (relative risk 0.67, 95% confidence interval 0.41 to 1.06, P=0.10). ASPECTS 8 to 10 were associated with a trend to larger benefit of tPA with a number needed to treat (NNT) of 5 versus ASPECTS 3 to 7 with a NNT of 8. CONCLUSIONS: There was no evidence of treatment effect modification by the baseline ASPECTS value in the NINDS rtPA Stroke Study. Therefore, exclusion of patients for thrombolysis within 3 hours of symptom onset based on EIC is not supported by our data. There is a trend to reduced mortality and increased benefit to rtPA if the baseline CT scan is favorable (ASPECTS >7).

Predicting final infarct size using acute and subacute multiparametric MRI measurements in patients with ischemic stroke.

PURPOSE: To identify early MRI characteristics of ischemic stroke that predict final infarct size three months poststroke. MATERIALS AND METHODS: Multiparametric MRI (multispin echo T2-weighted [T2W] imaging, T1-weighted [T1W] imaging, and diffusion-weighted imaging [DWI]) was performed acutely (<24 hours), subacutely (three to five days), and at three months. MRI was processed using maps of apparent diffusion coefficient (ADC), T2, and a self-organizing data analysis (ISODATA) technique. Analyses began with testing for individual MRI parameter effects, followed by multivariable modeling with assessment of predictive ability (R(2)) on final infarct size. RESULTS: A total of 45 patients were studied, 15 of whom were treated with tissue plasminogen activator (tPA) before acute MRI. The acute DWI and DWI-ISODATA mismatch lesion size, and the interactions of ADC, T2, and T2W imaging lesion with tPA remained in the final multivariable model (R(2) = 70%). A large acute DWI lesion or DWI < ISODATA lesion independently predicted increase in the final infract size, with predictive ability 68%. Predictive ability increased (R(2) = 83%) when subacute MRI parameters were included along with acute DWI, DWI-ISODATA mismatch, and acute T2W image lesion size by tPA treatment interaction. Subacute DWI > acute DWI lesion size predicted an increased final infarct size (P < 0.01). CONCLUSION: Acute-phase DWI and DWI-ISODATA mismatch strongly predict the final infarct size. An acute-to-subacute DWI lesion size change further increases the predictive ability of the model.

Direct infiltration of brainstem glioma along the cranial nerves.

The authors describe a case of a low-grade brainstem glioma extending along the cranial nerves without any evidence of leptomeningeal spread. The tumor extended directly along the VII-VIIIth cranial nerve complex and also along the trigeminal nerve, which is quite an unusual characteristic of the glial tumors.

Multiparametric iterative self-organizing MR imaging data analysis technique for assessment of tissue viability in acute cerebral ischemia.

BACKGROUND AND PURPOSE: Defining viability and the potential for recovery of ischemic brain tissue can be very valuable for patient selection for acute stroke therapies. Multiparametric MR imaging analysis of ischemic lesions indicates that the ischemic lesion is inhomogeneous in degree of ischemic injury and recovery potential. We sought to define MR imaging characteristics of ischemic lesions that are compatible with viable tissue. METHODS: We included patients with supratentorial ischemic stroke who underwent multiparametric MR imaging studies (axial multi-spin-echo T2-weighted imaging, T1-weighted imaging, and diffusion-weighted imaging) at the acute (< 24 hours) and outcome (3 months) phases of stroke. Using the algorithm Iterative Self-Organizing Data Analysis Technique (ISODATA), the lesion was segmented into clusters and each was assigned a number, called the tissue signature (white matter = 1, CSF = 12, all others between these two). Recovery was defined as at least a 20% size reduction from the acute phase ISODATA lesion volume to the outcome phase T2-weighted imaging lesion volume. The tissue signature data were collapsed into the following categories: < or = 3, 4, 5, and > or = 6. Logistic regression analysis included the following parameters: lesion volume, tissue signature value, apparent diffusion coefficient (ADC) value, relative ADC (rADC) expressed as a ratio, T2 value, and T2 ratio. The model with the largest goodness of fit value was selected. RESULTS: We included 48 patients (female-male ratio, 26:22; age, 64 [+/-14] years; 15 treated with recombinant tissue plasminogen activator [rt-PA] within 3 hours of onset; median National Institutes of Health Stroke Scale score, 7 [range, 2-26]). Median symptom onset-to-MR imaging time interval was 9.5 hours. With ISODATA processing, we generated 200 region-of-interest tissue records (one to nine tissue records per patient). Regarding tissue recovery, we detected a three-way interaction among ADC, ISODATA tissue signature, and previous treatment with rt-PA (P = .003). In the group not treated with rt-PA, ischemic tissues with acute rADC greater than the median (0.79) and tissue signature < or = 4 were more likely to recover (80% vs. 31% and 13%, odds ratio [95% CI]: 0.12 [0.05, 0.30] and 0.04 [0.01, 0.18] for tissue signatures 5 and 6, respectively). CONCLUSION: ISODATA multiparametric MR imaging of acute stroke clearly shows inhomogeneity and different viability of the ischemic lesion. Ischemic tissues with lower acute phase ISODATA tissue signature values (< or = 4) and higher rADC values (> or = 0.79) are much more likely to recover than those with higher signature values or lower rADC values. The effect of these factors on tissue recovery, however, is dependent on whether preceding treatment with rt-PA had been performed. Our approach can be a valuable tool in the design of therapeutic stroke trials with an extended time window.

MRI tissue characterization of experimental cerebral ischemia in rat.

PURPOSE: To extend the ISODATA image segmentation method to characterize tissue damage in stroke, by generating an MRI score for each tissue that corresponds to its histological damage. MATERIALS AND METHODS: After preprocessing and segmentation (using ISODATA clustering), the proposed method scores tissue regions between 1 and 100. Score 1 is assigned to normal brain matter (white or gray matter), and score 100 to cerebrospinal fluid (CSF). Lesion zones are assigned a score based on their relative levels of similarities to normal brain matter and CSF. To evaluate the method, 15 rats were imaged by a 7T MRI system at one of three time points (acute, subacute, chronic) after MCA occlusion. Then they were killed and their brains were sliced and prepared for histological studies. MRI of two or three slices of each rat brain (using two DWI (b = 400, b = 800), one PDWI, one T2WI, and one T1WI) was performed, and an MRI score between 1 and 100 was determined for each region. Segmented regions were mapped onto the histology images and scored on a scale of 1-10 by an experienced pathologist. The MRI scores were validated by comparison with histology scores. To this end, correlation coefficients between the two scores (MRI and histology) were determined. RESULTS: Experimental results showed excellent correlations between MRI and histology scores at different time points. Depending on the reference tissue (gray matter or white matter) used in the standardization, the correlation coefficients ranged from 0.73 (P < 0.0001) to 0.78 (P < 0.0001) using the entire dataset, including acute, subacute, and chronic time points. This suggests that the proposed multiparametric approach accurately identified and characterized ischemic tissue in a rat model of cerebral ischemia at different stages of stroke evolution. CONCLUSION: The proposed approach scores tissue regions and characterizes them using unsupervised clustering and multiparametric image analysis techniques. The method can be used for a variety of applications in the field of computer-aided diagnosis and treatment, including evaluation of response to treatment. For example, volume changes for different zones of the lesion over time (e.g., tissue recovery) can be evaluated.

Multiparametric MRI ISODATA ischemic lesion analysis: correlation with the clinical neurological deficit and single-parameter MRI techniques.

BACKGROUND AND PURPOSE: The purpose of this study was to show that the computer segmentation algorithm Iterative Self-Organizing Data Analysis Technique (ISODATA), which integrates multiple MRI parameters (diffusion-weighted imaging [DWI], T2-weighted imaging [T2WI], and T1-weighted imaging [T1WI]) into a single composite image, is capable of defining the ischemic lesion in a time-independent manner equally as well as the MRI techniques considered the best for each phase after stroke onset (ie, perfusion weighted imaging [PWI] and DWI for the acute phase and T2WI for the outcome phase). METHODS: We measured MRI parameters of PWI, DWI, T2WI, and T1WI from patients at the acute phase (<30 hours) and DWI, T2WI, and T1WI at the outcome phase (3 months) of ischemic stroke. The clinical neurological deficit was graded with the National Institutes of Health Stroke Scale (NIHSS). We compared the ISODATA lesion size with the PWI, DWI, and T2WI lesion sizes measured within the same slice at each phase. The lesion sizes were also correlated with NIHSS score of each phase. RESULTS: We included 11 patients; 9 (82%) were women, and 7 (64%) were black. The mean+/-SD age was 65.5+/-9.3 years (range, 45 to 82 years). The median NIHSS score was 15 (minimum, 4; maximum, 24)at the acute phase and 3 (minimum, 0; maximum, 22) at the outcome phase. The median time interval from stroke symptom onset to the acute MRI study was 10 hours (range, 6 to 29 hours), and the mean time interval to the outcome study was 93+/-11 days (range, 72 to 106 days). In the acute phase, the ISODATA lesion size had high correlation with the PWI lesion size (r=0.95; 95% CI, 0.89 to 0.98; P<0.0001), DWI lesion size (r=0.83; 95% CI, 0.66 to 0.92; P<0.0001), and T2WI lesion size (r=0.67; 95% CI, 0.39 to 0.84; P=0.008) and moderate correlation with NIHSS score (r=0.59; 95% CI, 0.02 to 0.88; P=0.06). In the outcome phase, the ISODATA lesion size had high correlation with the T2WI lesion size (r=0.97; 95% CI, 0.94 to 0.99; P<0.0001) and NIHSS score (r=0.78; 95% CI, 0.34 to 0.94; P=0.004). CONCLUSIONS: The integrated ISODATA method can identify and characterize the ischemic lesion independently of time elapsed since stroke onset. The ISODATA lesion size highly correlates with the PWI and DWI lesion size in the acute phase and with the T2WI lesion size in the outcome phase of ischemic stroke, as well as with the clinical neurological status of the patient.

Alveolar soft-part sarcoma of the neck.

We report a case of alveolar soft-part sarcoma involving the posterior paraspinal musculature of the neck. This rare tumor of uncertain histogenesis typically occurs in the lower extremities in young adults and in the tongue or orbit in infants.