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Sanjeev Chawla

Publications and source records attributed to Sanjeev Chawla.

15 recordsLinked to original sources
PubMed2006

Clinical signs for identification of neurocysticercosis in swine naturally infected with Taenia solium.

Taenia solium infection is a zoonotic disease and swine is the natural intermediate host. Till date no literatures have described clinical signs in swine indicative of brain involvement by cysticerci. In the present study we describe such clinical signs of porcine neurocysticercosis (NCC). These signs were excessive salivation, excessive blinking and tearing, and subconjunctival nodule. A total of 30 swine (18 with 2 or all 3 clinical signs and 12 without any sign) underwent magnetic resonance imaging (MRI). All 18 swine with above signs had NCC on MRI along with variable involvement of other organs that were subsequently confirmed by ex vivo MRI, necropsy and histopathology, while none of the 12 animals without any sign had NCC. As development of a porcine NCC model has proved difficult, we propose that naturally infected swine can be identified on the basis of these clinical signs and thus used as a model for further research on NCC.

Animals↗
PubMed2005

Diffusion-weighted EPI with magnetization transfer contrast.

Capabilities of diffusion-weighted (DW) and magnetization transfer (MT) imaging are well established for tissue characterization in various pathologies individually. However, the effect of suppression of macromolecules on applying MT pulse on signals associated with DW imaging and resulting change in the apparent diffusion coefficient (ADC) of water molecules has not been demonstrated previously. In the present study, we have performed DW echo planar imaging (EPI) with and without MT preparation pulse to see the effect of macromolecular signal suppression on ADC. A total of 10 normal volunteers and 20 patients with different intracranial cystic lesions [abscesses (n=10), cystic tumors (n=5), arachnoid cysts (n=5)] were subjected to DW imaging (b=0 and 1000 s/mm(2)) with and without MT saturation pulse. Analysis of region of interest (ROI) from different areas of white matter in normal volunteers and in the wall and cavity of cystic lesions in patients was carried out for calculating the ADC values. We found a significant increase (P<.05) in the ADC values in brain parenchyma and cavity of those intracranial cystic lesions having considerable amount of proteins after the application of MT preparation pulse except for arachnoid cysts. This is due to the size of the macromolecules present in the normal and abnormal tissue. Our studies suggest that this technique is likely to give a novel image contrast and may be of value in improving the tissue specificity in pathologies associated with variable macromolecular size.

Adolescent↗
PubMed2005

Diagnosis of bacterial cerebellitis: diffusion imaging and proton magnetic resonance spectroscopy.

Diffusion-weighted imaging and in vivo proton magnetic resonance spectroscopy ((1)H magnetic resonance spectroscopy) have demonstrated great potential in differentiating intracranial lesions of various pathologies. This report describes a case of a 12-year-old child with cerebellitis and subdural empyema that manifested presence of succinate, acetate, lactate, and amino acids on in vivo (1)H magnetic resonance spectroscopy from a large area of restricted diffusion in the vermis on diffusion-weighted imaging, a finding specific for bacteria-induced infection. The child made a complete clinical and imaging recovery on conservative management.

Central Nervous System Bacterial Infections↗
PubMed2004

Prediction of viability of porcine neurocysticercosis with proton magnetic resonance spectroscopy: correlation with histopathology.

Neurocysticercosis (NCC) is the most frequent parasitic disease of central nervous system. In our earlier study, we had observed creatine [(creatine + phosphocreatine); (tCr)] on ex vivo proton MR spectroscopy (1H MRS) in some of the cysticercus cyst fluid samples obtained from swine's brain parenchyma. In current study, swine brains of freshly slaughtered animals naturally infected with NCC were subjected to ex vivo magnetic resonance (MR) imaging on a 1.5Tesla MR system. Cysticercus cysts (n = 12) were removed from these brains and were labeled depending upon presence or absence of edema around cysts as observed on imaging. Cysticercus cyst fluid (100 microl) was subjected to different 1H MRS experiments and results were compared with histopathological examinations to look for any relationship between tCr and parameters like quantification of musculature, and cellular infiltration in wall of the parasite. Histopathology of cyst wall was categorized into two groups based on cellular characteristics and the amount of musculature. Grade I cysts (n = 5) with no or minimal inflammation and large amount of musculature showed tCr on 1H MRS. However, grade II cysts (n = 7) with profuse inflammation and less amount of musculature in the cyst wall lacked tCr. Higher amount of musculature in grade I cysts was associated with higher concentration of tCr in the cyst fluid (r2 = 0.93, P = 0.007). Creatine appears to be a marker of innocuous and viable NCC.

Animals↗
PubMed2004

Correlative MR imaging and histopathology in porcine neurocysticercosis.

PURPOSE: To examine whether all the histopathologically seen features of cysticercus cysts excised from brain of swine naturally infected with neurocysticercosis during its evolution are actually visible on magnetic resonance imaging (MRI). MATERIALS AND METHODS: Five swine naturally infected with cerebral cysticercosis were subjected to fast spin-echo (SE) T2, SE T1, fluid attenuated inversion recovery imaging, T1-weighted magnetization transfer (MT), and postcontrast T1-weighted MT sequences on MRI. These animals were sacrificed after imaging and ex vivo imaging of the intact excised brain using the same imaging protocol was also performed. Grossing of these brains was done similar to the ex vivo imaging planes. Numeral density and external appearance of each cyst and scolex were evaluated on each pulse sequence. Amount of pericystic edema, if present, was also assessed. On histopathology, cellular characteristics, inflammatory response, and the extent of edema, if present, in the brain parenchyma around the cysts were graded. Cysts were categorized into viable, early, and late degenerated on histopathology. The MRI features of each cyst were correlated with their histopathologic findings. RESULTS: Out of 31 cysts, eight were found to be viable, 13 early degenerated, and 10 late degenerated on histopathology. T2-weighted imaging demonstrated all the cysts while T1-weighted imaging showed 97% of the cysts. Scolex was seen in 90.3% and 93.5% of the cysts on T2- and T1-weighted images, respectively. Minimal edema (grade I) and inflammation in degenerating cysts present on histopathology was not visible on MRI. All but one of eight degenerated cysts, which showed enhancement on postcontrast MRI, had edema on imaging as well as on histopathology. CONCLUSION: T2-weighted MRI demonstrated all the cysts that were visible on histopathology. Non-enhancement of some of the degenerated cysts along with absence of edema on MRI is likely to underestimate the staging of neurocysticercosis evolution, and these early degenerating cysts may be misdiagnosed as in viable stage.

Animals↗
PubMed2003

Brain abscesses: etiologic categorization with in vivo proton MR spectroscopy.

PURPOSE: To compare the metabolite patterns observed at in vivo proton magnetic resonance (MR) spectroscopy of brain abscesses in patients for whom bacteriologic information was obtained from cultures and to categorize the MR spectral patterns with respect to the underlying etiologic agents. MATERIALS AND METHODS: MR imaging and in vivo single-voxel proton MR spectroscopic data obtained from 75 patients with brain abscesses were retrospectively analyzed. Ex vivo spectroscopic experiments with the pus from 45 of these patients also were performed, and the data were further categorized on the basis of bacteriologic information. Quantification of various metabolites and metabolite ratios and statistical analyses of lactate and lactate/amino acid (AA) ratio levels were performed by using one-way analysis of variance. RESULTS: On the basis of in vivo proton MR spectroscopic and bacteriologic analysis findings, data were classified into three categories: Group 1 data showed resonances of lactate, AAs, and acetate, with or without succinate at proton MR spectroscopy; cultures for this group showed obligate anaerobes or a mixture of obligate and facultative anaerobes. The metabolite patterns in the group 2 and group 3 data were similar to the pattern of the group 1 data, with the exception that acetate and succinate resonances were absent. Culture was positive for either obligate aerobes or facultative anaerobes in group 2 and was sterile in group 3. At analysis of variance, in vivo data showed significant differences in lactate/AA ratios (P =.008), and ex vivo data showed significant differences in lactate levels (P =.001) among the three groups. CONCLUSION: It is possible to differentiate anaerobic from aerobic or sterile brain abscesses on the basis of metabolite patterns observed at in vivo proton MR spectroscopy. This information may be useful in facilitating prompt and appropriate treatment of patients with these abscesses.

Acetates↗
PubMed2003

Magnetization transfer and T2 quantitation in normal appearing cortical gray matter and white matter adjacent to focal abnormality in patients with traumatic brain injury.

Traumatic brain injury (TBI) is one of the commonest causes of morbidity and mortality in the developed countries with posttraumatic epilepsy and functional disability being its major sequelae. The purpose of this study was to test the hypothesis whether the normal appearing adjacent gray and white matter regions on T2 and T1 weighted magnetization transfer (MT) weighted images show any abnormality on quantitative imaging in patients with TBI. A total of 51 patients with TBI and 10 normal subjects were included in this study. There were significant differences in T2 and MT ratio values of T2 weighted and T1 weighted MT normal appearing gray matter regions adjacent to focal image abnormality compared to normal gray matter regions in the normal individuals as corresponding contralateral regions of the TBI patient's group (p < 0.05). However the adjoining normal appearing white matter quantitative values did not show any significant change compared to the corresponding contralateral normal white matter values. We conclude that quantitative T2 and MT ratio values provide additional abnormality in patients with TBI that is not discernable on conventional T2 weighted and T1 weighted MT imaging especially in gray matter. This additional information may be of value in overall management of these patients with TBI.

Adolescent↗
PubMed2003

Teratocarcinosarcoma of the nose, paranasal sinuses and nasopharynx.

Teratomas affecting the head and neck are rare tumours of ambiguous origin. The benign form is seen in children and mostly affects the nasopharynx. Malignant tumours in the upper jaw have been reported rarely. They are almost exclusively seen in the adult male. They are highly aggressive tumours that are difficult to diagnose pre-operatively due to the varied histological patterns. Treatment options available are surgery, radiotherapy or a combination of both. Despite intensive treatment, the prognosis is still poor. A rare case of teratocarcinosarcoma of the nose, paranasal sinuses and nasopharynx in a 25-year-old male is presented. The tumour had a non-germ cell tumour origin. The clinical features, pathologic characteristics and treatment are detailed. It was managed by surgery, radiotherapy and chemotherapy.

Adult↗
PubMed2003

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.

Adolescent↗
PubMed2002

Differentiation of hydatid cyst from cysticercus cyst by proton MR spectroscopy.

The metabolite patterns obtained by ex vivo proton MR spectroscopy of fluid from different locations of hydatid cysts of sheep and humans (n = 16) and cysticercus cysts of swine and humans (n = 25) were compared with an objective of differentiating the two parasites on the basis of their metabolite pattern. The spectra from hydatid fluid differed from cysticercus cyst by the absence of creatine in the former. When the hydatid cyst was fertile, malate and/or fumarate was also observed, which was absent in cysticercus cyst. The most likely explanation for the presence of creatine only in the cysticercus fluid is its active diffusion from the surrounding host tissue along with a contribution from the musculature present in the bladder wall of the cyst.

Animals↗
PubMed2002

Fertility assessment of hydatid cyst by proton MR spectroscopy.

BACKGROUND: Hydatid cysts, the larvae of the parasite Echinococcus granulosus, may lodge in any organ of intermediate hosts, namely, man and sheep. Complete cyst removal is the treatment of choice; however, spillage of fertile cysts during surgery leads to disease recurrence that may be prevented by preoperative detection of the fertility status of the cyst. With this perspective, ex vivo proton (1H) MR spectroscopy of hydatid fluid of human and sheep origin was performed to differentiate fertile from sterile cysts on the basis of their metabolite pattern. PATIENTS AND MATERIALS: Cysts of sheep and human origin were used as source of hydatid fluid. A fraction of this fluid was tested for cyst fertility and the rest was used for ex vivo1H spectroscopy. Histopathology of the cyst wall was done as a gold standard for this study. RESULTS: Of 10 sheep samples, 7 were fertile and 3 were sterile, while among 6 human samples, 5 were fertile and 1 was sterile. Spectroscopic and histopathological results corroborated each other. The fluid from microbiologically proven fertile cysts contained malate and fumarate along with other resonances and the histopathology of the fertile cyst wall demonstrated germinal lining and protoscoleces. CONCLUSIONS: The ex vivo spectroscopic differentiation of fertile and sterile cysts may be a stepping-stone for their in vivo separation in future and thus help in framing strategies for percutaneous/surgical management.

Animals↗
PubMed2002

Comparative evaluation of magnetization transfer MR imaging and in-vivo proton MR spectroscopy in brain tuberculomas.

We have compared and analyzed the value of in vivo proton MR spectroscopy (PMRS) and T1 weighted magnetization transfer (MT) MR imaging in tissue characterization of brain tuberculomas. We studied 33 cases of proven intracranial tuberculomas with in vivo PMRS and T1 weighted MT MR imaging. MT ratios from the rim and core of the tuberculomas were calculated and compared with metabolites seen on PMRS. Final diagnosis of tuberculoma was based on histopathology (n = 26) and/or associated tuberculous meningitis (n = 7) in all the cases. Out of the 33 patients who underwent both PMRS and T1 weighted MT MR imaging, spectroscopy showed only lipids at 0.9 ppm, 1.3 ppm, 2.0 ppm, and 2.80 ppm in 26 cases while lipids at 0.9 ppm, 1.3 ppm, 2.0 ppm and 2.80 ppm along with choline at 3.22 ppm was seen in remaining 7 patients. MT ratios from the core or solid necrosis varied from 21-29% while from the rim or cellular region varied from 16-24%. MT ratios from all the 33 lesions were consistent with tuberculomas while PMRS showed choline along with lipids in 7 predominantly cellular lesions simulating a neoplasm. We conclude that T1 weighted MT MR imaging appears to be more consistent in the tissue characterization of brain tuberculomas.

Adolescent↗
PubMed2002

Demonstration of scolex within calcified cysticercus cyst: its possible role in the pathogenesis of perilesional edema.

PURPOSE: This study was performed to understand the relation between the scolex as demonstrated on gradient echo (GRE) imaging in a calcified cysticercus cyst and the development of perilesional edema that may be of value in understanding the pathogenesis of this entity. METHODS: Twenty-one patients with solitary calcified lesion on computed tomography (CT), with seizures of recent onset (within 15 days), were selected for this study. All the patients were subjected to magnetic resonance imaging (MRI) including GRE imaging. The patients were grouped on the basis of presence or absence of perilesional edema around the calcified lesion on MRI. RESULTS: There were 14 patients with perilesional edema, and seven patients had no evidence of edema. Of these 14 patients with perilesional edema, rim enhancement was detected in 13 patients on postcontrast MRI, whereas no enhancement was observed in one patient. The scolex was seen in all these 14 patients on GRE images. Of the seven patients without evidence of edema, the scolex was not seen in any of these patients on GRE imaging. In addition, there was no evidence of any contrast enhancement on postcontrast study in any of the patients in this group. CONCLUSIONS: We conclude that the calcified cysts with scolex seen on GRE imaging are associated with perilesional edema. This is probably due to preservation of antigenic material in these calcified cysts, the release of which provokes an inflammatory response that may be responsible for the perilesional edema.

Adolescent↗
PubMedDate not supplied

Human and porcine Taenia solium infection in rural north India.

72 members of a pig farming community and 50 slaughtered pigs in Uttar Pradesh, India, were examined between November 2000 and June 2001 for Taenia solium infection. 27 of the human subjects (38%) had intestinal taeniasis and 7 (9.7%) had reported seizures. All 3 of the latter who were examined had neurocysticercosis. 13 of the pigs (26%) had cysticercosis. Such high prevalences indicate the need for detailed assessment of the disease burden in this community.

Agricultural Workers' Diseases↗