Comparative assessment of therapeutic response to physiotherapy with or without botulinum toxin injection using diffusion tensor tractography and clinical scores in term diplegic cerebral palsy children.

The present study was to compare the effects of combined therapy [botulinum (BTX) plus physiotherapy] with physiotherapy alone using diffusion tensor imaging (DTI) derived fractional anisotropy (FA) values of motor and sensory fiber bundles and clinical grade of the disability to see the value of BTX in term children with spastic diplegic cerebral palsy (CP). Clinically diagnosed 36 children participated in the study. All these children were born at term, and had no history of seizures. The study was randomly categorized into two groups: group I (n=18) - physiotherapy alone and group II (n=18) - physiotherapy plus BTX injection. Quantitative diffusion tensor tractography on all these children was performed on motor and sensory fiber bundles on baseline as well as after 6months of therapy. Motor function and clinical grades were also measured by gross motor function measures (GMFM) scale on both occasions. We observed significant change in FA value in motor and sensory fiber bundle as well as in GMFM scores at 6months compared to baseline study in both the groups. However, delta change and relative delta change in FA values of sensory and motor fiber bundle as well as GMFM score between group I and group II was statistically insignificant. We conclude that addition of BTX to physiotherapy regimen does not influence the outcome at 6months with similar insult in children with term diplegic spastic CP. This information may influence management of diplegic CP especially in developing countries, where BTX is beyond the reach of these children.

Quantification of age- and gender-related changes in diffusion tensor imaging indices in deep grey matter of the normal human brain.

This study aimed to demonstrate age-related and gender-related changes in diffusion tensor imaging (DTI) indices of deep grey matter (GM) nuclei of the normal human brain. DTI was performed on 142 subjects (age: 10-52 years). Regions of interest were placed on the caudate nucleus (CN), putamen, globus pallidus, frontal white matter (WM), occipital WM, anterior and posterior limb of internal capsule, genu of the corpus callosum and splenium in all participants. The quadratic regression model was used to describe age-related and gender-related changes in DTI indices for GM and WM. We observed increased fractional anisotropy (FA) values with age up to adulthood in GM, and a rise up to the third decade of life followed by a decrease in FA for WM. We observed higher FA values in males compared to females in CN and all WM regions. Decreased mean diffusivity with age was observed in GM and WM irrespective of gender. This normative data may be valuable in the diagnosis of neurodegenerative diseases.

Correlation of CSF proinflammatory cytokines with MRI in tuberculous meningitis.

RATIONALE AND OBJECTIVES: To demonstrate the correlation of proinflammatory cytokines (PCs), intercellular adhesion molecule (sICAM-1), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1beta (IL-1beta) in CSF of tuberculous meningitis (TBM) patients with magnetic resonance imaging (MRI) including diffusion tensor imaging (DTI) and also to look for the changes in imaging parameters after antitubercular treatment (ATT) in these patients. MATERIALS AND METHODS: Forty patients with TBM (median age, 27.7 years) and 30 age-/sex-matched controls were included in this study. PCs were quantified from the CSF of TBM patients at the time of hospital admission (baseline). MRI including DTI was performed at the time of baseline study and 6 months after ATT. RESULTS: Significant positive correlation of PCs with fractional anisotropy (FA) values and post-contrast signal intensity (PCSI) collected from cerebral cortical regions was observed in TBM patients. A significant positive correlation of FA values with PCSI was also observed at both time points in patient groups. At baseline study significantly high FA values were observed in patients compared to controls. Significantly decreased FA values and PCSI were observed in the patients after 6 months of ATT compared to the baseline study. CONCLUSIONS: Results of this study suggest that the DTI-derived anisotropy have the potential to delineate meningeal inflammation and it may be used in assessment of therapeutic response in TBM patients as an additional method to conventional imaging.

Understanding development and lateralization of major cerebral fiber bundles in pediatric population through quantitative diffusion tensor tractography.

Region of interest based morphometric diffusion tensor imaging analysis, has been used extensively for the assessment of age-related changes in human brain, is limited to two dimensions and does not reflect the whole fiber bundle; however, diffusion tensor tractography (DTT) offers an overall view of individual fiber bundle in three-dimensional spaces. Quantitative DTT was performed on 51 healthy subjects of pediatric age range and young adults to compare age-related fractional anisotropy (FA) changes in corpus callosum, sensory and motor pathways, limbic tracts [cingulum (CNG) and fornix (Fx)], and superior and inferior longitudinal fascicules. In corpus callosum, inferior longitudinal fascicules, limbic tracts (CNG and Fx), sensory pathways, and motor pathways, an initial sharp increase in FA was observed up to the age of 2 y followed by a gradual increase up to 21 y. In superior longitudinal fascicules, sharp increase in FA was observed up to 3 y followed by a gradual increase. The FA value of the left CNG (p = 0.01, sign test) was observed to be significantly greater than that of the right CNG. We conclude that white matter fiber tracts mature with age and can be assessed by using DTT that may greatly improve our understanding of the human brain development.

Abdominal fat distribution and insulin resistance in Indian women with polycystic ovarian syndrome.

The relationship between insulin resistance and abdominal fat distribution was studied in Indian patients with PCOS. Subcutaneous fat, together with a family history of type 2 diabetes mellitus, was the best marker of insulin resistance.

Dynamic contrast-enhanced derived cerebral blood volume correlates better with leak correction than with no correction for vascular endothelial growth factor, microvascular density, and grading of astrocytoma.

OBJECTIVE: To look for the impact of leak correction on correlation of perfusion indices with microvessel density (MVD) and vascular endothelial growth factor (VEGF) in astrocytomas. METHODS: Dynamic contrast-enhanced magnetic resonance imaging was performed in 64 patients with varying grades of astrocytoma. Perfusion indices (ie, relative cerebral blood volume (rCBV) with and without leak correction, relative cerebral blood flow (rCBF), permeability (k(trans)), and leakage (v(e)) were quantified. MVD and VEGF-expressing cells were quantified from the excised tumor tissues and were correlated with perfusion metrics. RESULTS: Perfusion indices showed significant difference among the astrocytoma grades. The corrected rCBV correlated better with MVD and VEGF. The corrected rCBV correlated (r = 0.853, P = <0.001) strongly, whereas the uncorrected rCBV (r = 0.592, P = <0.001) and k(trans) (r = 0.498, P = 0.001) correlated moderately with tumor grade. The corrected rCBV discriminated 100% low-grade from high-grade astrocytoma, while uncorrected rCBV did this in 95.5% low-grade and 71.4% high-grade astrocytoma. CONCLUSIONS: Corrected rCBV better correlates with grade and is more accurate in discriminating low-grade from high-grade astrocytoma compared with uncorrected rCBV.

Relative cerebral blood volume is a measure of angiogenesis in brain tuberculoma.

OBJECTIVE: The aim of this study was to correlate the perfusion indices with magnetic resonance imaging-derived cellular and necrotic fraction of the tuberculoma and angiogenesis metrics on histopathology. METHODS: We performed dynamic contrast-enhanced magnetic resonance imaging in 13 excised brain tuberculoma patients. Microvascular density and vascular endothelial growth factor (VEGF)-expressing cells were quantified from the excised tuberculoma. The cellular and necrotic fractions of the tuberculomas were quantified on a postcontrast T1-weighted imaging. RESULTS: Relative cerebral blood volume of cellular portion significantly correlated with cellular fraction volume (r = 0.882, P < 0.001), microvascular density (r = 0.900, P < 0.001), and VEGF (r = 0.886, P < 0.001) of the 13 excised tuberculomas. Microvascular density also correlated significantly with VEGF (r = 0.919, P < 0.001). CONCLUSIONS: Relative cerebral blood volume is a measure of angiogenesis in the cellular fraction of the brain tuberculoma. This information may be of value in predicting the therapeutic response in future.

Improved T(1)-weighted dynamic contrast-enhanced MRI to probe microvascularity and heterogeneity of human glioma.

Dynamic contrast-enhanced (DCE) T(1)-weighted magnetic resonance imaging (MRI) is a powerful tool capable of providing quantitative assessment of contrast uptake and characterization of microvascular structure in human gliomas. The kinetics of the bolus injection doped with increasing concentrations of gadopentate dimeglumine (Gd-DTPA) depends on tissue as well as pulse sequence parameters. A simple method is described that overcomes the limitation of relative signal increase measurement and may lead to improved accuracy in quantification of perfusion indices of glioma. Based on an analysis of the contrast behavior of spoiled gradient-recalled echo sequence; a parameter K with arbitrary unit 5.0 is introduced, which provides a better approximation to the differential T(1) relaxation rate. DCE-MRI measurements of relative cerebral blood volume (rCBV) and cerebral blood flow (rCBF) were calculated in 25 patients with brain tumors (15=high-grade glioma, 10=low-grade glioma). The mean rCBV was 6.46 +/- 2.45 in high-grade glioma and 2.89 +/- 1.47 in the low-grade glioma. The rCBF was 3.94 +/- 1.47 in high-grade glioma while 2.25 +/- 0.87 in low-grade glioma. A significant difference in rCBF and rCBV was found between high- and low-grade gliomas. This simple and robust technique reveals the complexity of tumor vasculature and heterogeneity that may aid in therapeutic management especially in nonenhancing high-grade gliomas. We conclude that the precontrast medium steady-state residue parameter K may be useful in improved quantification of perfusion indices in human glioma using T(1)-weighted DCE-MRI.

Magnetization transfer MR imaging in patients with posttraumatic epilepsy.

BACKGROUND AND PURPOSE: Intractable epilepsy is a well-recognized complication following head trauma, and many factors have been implicated in its pathogenesis. This study was performed to determine the severity of tissue damage after severe head injury as assessed with magnetization transfer (MT) MR imaging and the relationship of this damage with seizure intractability. METHODS: Forty-four patients, 13 without seizures (disease controls) and 31 with seizures, underwent T1-weighted MT MR imaging 1-10 years after head trauma. Phase-corrected gradient-echo (GRE) imaging was also performed in all patients to look for the presence of hemosiderin. All patients were evaluated for the presence of an MT abnormality beyond an abnormality seen on T2-weighted images, an MT abnormality within a T2 abnormality, and hemosiderin deposition. RESULTS: Patients with an MT abnormality beyond a T2 abnormality had a significantly higher intractability of seizures compared with those with an MT abnormality within a T2 abnormality (P <.05). In addition, the mere presence of hemosiderin deposit was not associated with seizure intractability; however, gliosis around the hemosiderin as seen on T1-weighted MT images was associated with seizure intractability. CONCLUSIONS: T1-weighted MT imaging may be of value in predicting the intractability of the seizure in delayed posttraumatic epilepsy.