Browsing by Author "Kapilamoorthy, T. R."

Now showing 1 - 15 of 15
  • Item
    Airway implications of post-ductal coarctation of the aorta and an aberrant right subclavian artery
    (CANADIAN JOURNAL OF ANAESTHESIA-JOURNAL CANADIEN D ANESTHESIE, 2008)
  • Item
    An unusual chest radiograph
    (JOURNAL OF CARDIOTHORACIC AND VASCULAR ANESTHESIA, 2007)
  • Item
    Embryonal tumor with multilayered rosettes: Two case reports with a review of the literature
    (NEUROLOGY INDIA, 2012)
    Embryonal tumor with multilayered rosettes (ETMR) is a well-recognized histopathological variant of primitive neurectodermal tumors of the central nervous system. This tumor depicts histopathological features that are common to both ependymoblastoma (EBL) and neuroblastoma. Here we report two pediatric cases of ETMR, one exhibiting dominant neuronal differentiation and the other with dominant glial differentiation, thereby expanding the previously known pathologic spectrum. The varying histological features, common morphologic diagnostic difficulties as well as variable postsurgical survival of this entity compared to similar embryonal tumors are highlighted.
  • Item
    Endovascular treatment of direct carotid cavernous fistulae: a pictorial review
    (NEURORADIOLOGY, 2006)
    Introduction Direct carotid-cavernous fistulae (CCFs) are type A fistulae according to Barrow's classification. Endovascular treatment of these lesions is challenging.Methods The purpose of this review was to evaluate the endovascular treatment of direct CCFs. We also describe the technique, symptomatology and complications associated with the procedure and report on the long-term follow-up in our treated patients.Results A total of 89 patients with a direct CCF were treated. All patients had baseline brain CT or MR imaging. Treatment comprised transarterial balloon or coil embolizations. The patients were followed up at 1 month and then every 6 months thereafter. Detachable balloons were used in 79 fistulae. In 12 fistulae the balloon could not be negotiated through the fistula and these fistulae were treated with transarterial coil occlusion. Clinical outcomes of the treated patients evaluated at 1 month were: 79 patients (88.8%) cured, 9 (10.1%) significantly improved, 1 (1.1%) remaining static.Conclusion Endovascular treatment of direct CCFs is safe and effective and results in long-term cure.
  • Item
    Endovascular treatment of scalp cirsoid aneurysms
    (NEUROLOGY INDIA, 2008)
    Background: Scalp is the most common site of soft tissue arteriovenous fistulae and surgical excision has been the primary mode of treatment. Endovascular treatment has evolved as an alternative to the surgery. Aims: To evaluate the effectiveness of percutaneous direct-puncture embolization of cirsoid aneurysms. Materials and Methods: From January 1995 to December 2004, 15 patients underwent percutaneous direct-puncture embolization of cirsoid aneurysms. Plain X-ray, computerized tomography scan and complete selective cerebral angiogram were done in all. Seven patients had forehead lesions, four had temporal and the remaining four patients had occipital region cirsoid aneurysms. Lesions were punctured with 21-gauge needle and embolized with 20-50% cyanoacrylate-lipiodol mixture. Circumferential compression was applied during injection. Results: Post-embolization angiogram showed complete obliteration in 11 patients. The remaining four patients required adjunctive transarterial embolization with polyvinyl alcohol particles for complete lesion devascularization. Two patients had post procedure surgery for removal of disfiguring and hard glue cast. There were no major procedure-related complications. No patients had any recurrence in the follow-up. Conclusion: Percutaneous direct puncture embolization of cirsoid aneurysms is a safe and effective procedure. It can be effectively used as an alternative to surgery. Sometimes adjunctive transarterial embolization is also required to deal with deeper feeders.
  • Item
    Fluid-fluid levels in cystic lumbosacral schwannomas: a report of three cases
    (SINGAPORE MEDICAL JOURNAL, 2009)
    Magnetic resonance imaging features of three benign cystic lumbosacral schwannomas, which showed multiple fluid-fluid levels, are described. One of the tumours showed bone destruction with fluid-fluid levels that closely mimicked an aneurysmal bone cyst. Pathological examination confirmed haemorrhage as the cause of fluid-fluid levels in the tumours. Though a rare finding, fluid-fluid levels with bone destruction can also be caused by nerve sheath tumours and hence must be included in the list of differential diagnoses of spinal tumours.
  • Item
    Fluoroscopic-guided balloon dilatation and stenting in tracheal stenosis with metallic self-expandable stents and long-term follow-up results
    (AUSTRALASIAN RADIOLOGY, 2007)
    The purpose of this study was to assess the safety and long-term efficacy of self-expandable stents in the treatment of benign tracheal stenosis. Nine patients (seven men) with tracheal stenosis (including one with fistula) of varied cause were treated by fluoroscopically guided balloon dilatation and stenting with self-expandable metallic stents. The procedure was carried out under topical spray in eight patients and under general anaesthesia in one patient. The patients were followed up for a period ranging between 13 and 60 months. in eight of the nine patients, satisfactory positioning of the stent was achieved at the first instance, with immediate relief of dyspnoea. One patient with innominate artery aneurysm died 16 days after the procedure because of renal failure. At 1 month of follow up, six out of eight (75%) of our live patients were without any respiratory embarrassment. This dyspnoea-free result reached almost 90% by the end of 1 year especially so in the fibrous strictures. Four out of the eight live patients (50%) had cough for 2 months and two (25%) had mild blood-tinged sputum treated by inhalation and mucolytic agents. Secondary intervention was required in one patient at 1 month because of recurrent symptoms. The patient with tracheo-oesophageal fistula required surgical intervention because of fracture of the stent. Fluoroscopically guided balloon dilatation and stenting of the tracheal stenosis is an effective non-surgical therapy resulting in cure of fibrous strictures and palliation in cases of malignancy.
  • Item
    Germinoma of medulla
    (NEUROLOGY INDIA, 2010)
    Germinoma occurring in the medulla oblongata is extremely rare. We report a case of primary intracranial germinoma arising in the medulla oblongata of a 24-year-old postpartum female who presented with progressive weakness of upper and lower limbs, seventh nerve palsy, and decreased palatal movements. Her MR imaging showed a heterointense mass lesion in the posterior portion of upper medulla, the histology of which was reported as germinoma. Germ cell tumors should be considered in the differential diagnosis of tumors occurring in the brain stem.
  • Item
    Glioma grading: sensitivity, specificity, positive and negative predictive values of diffusion and perfusion imaging
    (JOURNAL OF NEURO-ONCOLOGY, 2009)
    Purpose The purpose of our study was to determine the statistical significance of thresholds of relative cerebral blood volume (rCBV), apparent diffusion coefficient (ADC) and ADC ratios in grading cerebral gliomas. Materials and methods In this retrospective study, 51 patients with histopathologically confirmed primary cerebral gliomas who had undergone conventional MR imaging, dynamic contrast-enhanced T2*-weighted perfusion MR imaging and diffusion MR imaging were included. A retrospective blinded analysis of the imaging findings including the perfusion and diffusion parameters was done. The rCBV measurements were obtained from regions of maximum perfusion. Minimum ADC values were obtained from the region of maximum hypointensity within the tumor and from the corresponding opposite white matter. Tumor grade determined with the two methods were then compared with the histopathologic grade. Mann-Whitney tests were performed to compare the DWI and PWI between tumor types. Receiver operating characteristic analyses were performed to determine optimum thresholds for tumor grading and also to calculate the sensitivity, specificity, PPV, and NPV for identifying high-grade gliomas. Results Statistical analysis demonstrated a threshold value of 2.91 for rCBV to provide sensitivity, specificity, PPV, and NPV of 94.7, 93.75, 90.0, and 96.8%, respectively, in determining high-grade gliomas. An ADC value of 98.50 mm(2)/s was defined as a threshold below which tumors were classified as high-grade gliomas and a sensitivity, specificity, PPV, and NPV of 90, 87.1, 81.81 and 93.10% respectively, were obtained. Significant differences were noted in the rCBV ratios, ADC and ADC ratios between low- and high-grade gliomas (P < 0.0001). Conclusion Combining PWI and DWI with conventional MR imaging increases the accuracy of pre-operative imaging grading of glial neoplasms. The rCBV measurements had the most superior diagnostic performance in predicting glioma grade. Absolute ADC values or ADC ratios were also helpful in preoperative grading of gliomas. Threshold values can be used in a clinical setting to evaluate tumors preoperatively for histologic grade and provide a means for guiding treatment and predicting postoperative patient outcome.
  • Item
    Mean intensity curve on dynamic contrast-enhanced susceptibility-weighted perfusion MR imaging - review of a new parameter to differentiate intracranial tumors
    (JOURNAL OF NEURORADIOLOGY, 2011)
    Dynamic susceptibility contrast (DSC) perfusion imaging has been in clinical use for various indications, including characterization and grading of intracranial neoplasms. However, several technical factors can lead to pitfalls in image interpretation. This review discusses the extraction of T1 and T2* information from mean curve analysis of DSC perfusion imaging of various brain tumors, which provides further insights into tumor biology and, thus, may be useful in the differential diagnosis of such tumors. Indeed, by looking at the mean time signal intensity curve from the tumor bed in addition to the rCBV maps, it is possible to obtain further inferences of capillary density and lesion leakiness. When dynamic contrast enhanced (DCE) T1 perfusion is not available, DSC perfusion with mean curve analysis appears to be a valid alternative for characterizing various brain neoplasms in a routine clinical setting. (C) 2011 Elsevier Masson SAS. All rights reserved.
  • Item
    Metabolite signature of developmental foregut cyst on in vivo and in vitro H-1 MR spectroscopy
    (JOURNAL OF MAGNETIC RESONANCE IMAGING, 2008)
    Foregut duplication cysts are developmental anomalies of the bronchopulmonary foregut and are common cystic lesions of the mediastinum. We describe a case of mediastinal foregut duplication cyst with in vivo H-1 MR spectroscopy on a 1.5T magnet showing a large metabolite peak at 2.02 ppm, attributable to N-acetylated compounds, in addition to a smaller peak at 1.33 ppm, considered to represent lipids. In vitro NMR spectroscopy (7.05T) of cyst fluid confirmed the presence of these peaks. In addition; a broad multiplet centered at 3.7 ppm, possibly from various protons of the hexose ring system, was also noted. Chemical analysis of the cyst fluid demonstrated the presence of N-acetylhexosamines, proteins, and lipids: Again, in vitro spectra of pure samples of N-acetylglucosamine and N-acetylgalactosamine were obtained for comparison, which better resolved the N-acetyl peak and the peaks at 3.7 ppm. The mucus secreted by respiratory epithelium and the mucous glands of the foregut cysts contains glycoproteins that have N-acetylhexosamines as components and lipid breakdown products that are thought to contribute to the observed spectrum. This information might be useful in predicting the cyst content and, in turn, the lining of the epithelium and the glandular elements.
  • Item
    Preoperative embolization of hypervascular head and neck tumours
    (AUSTRALASIAN RADIOLOGY, 2007)
    The embolization of vascular tumours of the head and neck has become an important adjunct to the surgical treatment of these tumours. A vascular tumour in the head and neck region in a surgically treatable patient may be a candidate for embolization. Palliative embolization may be the sole treatment for high risk patients. Reducing intraoperative bleeding may shorten surgery time thus decreasing morbidity and mortality. The purpose of this study is to assess the efficacy of embolization as an adjunct to surgery or as a curative measure in the management of hypervascular head and neck tumours. We retrospectively reviewed the records of 46 consecutive patients (27 men and 16 women; mean age, 37.8 years) with 48 hypervascular head and neck tumours that had undergone preoperative transarterial, direct puncture or combined mode of embolization. Diagnosis of tumours was made on the basis of findings of imaging studies. The 46 patients underwent embolization either through transarterial route, by direct puncture technique or both direct puncture and arterial route. The devascularization reached 90-95% with the use of NBCA. The amount of devascularization reached by transarterial particle embolization is a little lesser. One patient (carotid body tumour) developed mild unilateral seventh, ninth and 10th cranial nerve palsy after transarterial embolization, transient hemiparesis was seen in another patient (nasopharyngeal angiofibroma). Both patients improved completely with steroids and had no deficit on follow up. One patient developed delayed glue migration into the middle cerebral artery territory 6 h after the procedure with no reported increase in size of the lesion in the following 5 years. Preoperative embolization of hypervascular tumour of head and neck region appears to be safe and improves the chance of complete removal during surgery with minimal blood loss.
  • Item
    Rhabdoid and papillary meningioma with leptomeningeal dissemination
    (JOURNAL OF NEURORADIOLOGY, 2008)
    Rhabdoid meningioma is a rare variant of meningioma classified as grade III under the new World Health Organization (WHO) classification of brain tumors. Although this tumor is known for its aggressive behavior, dissemination into cerebral. spinal fluid (CSF) is extremely rare. We report here a case of rhabdoid meningioma in a young man, operated on twice previously, who presented with multiple CSF areas of seeding in the brain and spinal cord. The imaging findings for this tumor, including diffusion and perfusion MR sequences, are highlighted. This particular histological subtype of meningioma has a poor prognosis and must be treated aggressively. (C) 2008 Elsevier Masson SAS. All rights reserved.
  • Item
    Uncommon presentation of intracranial cryptococcal infection mimicking tuberculous infection in two immunocompetent patients
    (SINGAPORE MEDICAL JOURNAL, 2009)
    Cryptococcal infection of the brain is commonly seen in immunocompromised patients but rarely considered as the differential diagnosis in immunocompetent patients. We present two cases of cryptococcosis involving the brain in immunocompetent patients, which strongly mimicked tuberculous infection in both conventional as well as advanced magnetic resonance (MR) imaging, and the disease was only confirmed after histopathological/cerebrospinal fluid serological study. One patient was a 52-year-old woman, and the second patient was a 23-year-old man. These two cases highlight the need for workup of fungal infections in immunocompetent patients from the tuberculous endemic regions, even when the imaging is highly suspicious of tuberculous lesions. The imaging findings in advanced MR imaging techniques such as diffusion, perfusion, susceptibility-weighted imaging and MR spectroscopy are discussed.
  • Item
    Usefulness of T2*-weighted MR sequence for the diagnosis of subfrontal schwannoma
    (JOURNAL OF NEURORADIOLOGY, 2007)
    Subfrontal schwannomas are rare tumors that are usually diagnosed during surgery. They are often misdiagnosed as meningioma or esthesioneuroblastoma because of their similar clinical and radiological features. We report a case of schwannoma arising from the floor of the anterior cranial fossa that had radiological features similar to that of meningioma. However, T2*-weighted MR imaging revealed multiple foci of Low signal intensities within the tumor related to microbleeds, which suggested a diagnosis of schwannoma that was confirmed by histopathology. This case report demonstrates the usefulness of T2*-weighted sequence in distinguishing meningioma from schwannoma, especially in cases where the tumor has an unusual location. (C) 2007 Elsevier Masson SAS. All rights reserved.