Introduction: Pial arteriovenous fistula (PAVF) is a rare intracranial vascular malformation with diverse clinical presentations. Early diagnosis and intervention are crucial due to its poor natural history. Endovascular treatment has emerged as a preferred option with promising results. Case Report: We report a case of an 8-month-old infant who presented with recurrent focal seizures and acute intraparenchymal hematoma. Further investigation with magnetic resonance angiography and digital subtraction angiography confirmed the presence of a PAVF. Results: Endovascular embolization successfully obliterated the PAVF with no postprocedural complications. Clinical follow-up demonstrated a favorable outcome. Conclusion: This case highlights the significance of early detection through suitable imaging modalities and timely intervention in preventing life-threatening complications associated with PAVFs. Endovascular embolization offers an effective and safe treatment option for pediatric PAVFs, leading to positive outcomes in this rare entity.

We report a case of recurrence pneumocephalus in a 42-year-old man who underwent transnasal CSF leak repair for left lateral sphenoid meningocele, with thecoperitoneal(TP) shunt. The pneumocephalus was attributed to negative intracranial pressure created by an over draining shunt in the presence of multiple skull base defects.

Spontaneous intracranial hypotension (SICH) is the emerging cause of orthostatic headache as it has been better recognized in recent years. SICH happens due to spinal cerebrospinal fluid (CSF) leak; however, the manifestations are predominantly cranial and hence imaging in SICH includes brain and spine. There are few characteristic brain imaging features to be concerned about to diagnose SICH in patients with vague symptoms or low clinical suspicion. Spine screening is recommended in these patients to assess spinal CSF leaks. While neuroradiologists play a significant role from the time of diagnosis to treatment of SICH, there is a need for all the general radiologists to be aware of the condition. Computed tomography myelogram and digital subtraction myelogram are performed for diagnostic and therapeutic management of SICH. There is a known risk for SICH recurrence in patients with sagittal longitudinal epidural collection and hence, targeted blood patch should be used instead of blind patch. Most importantly, slow mobilization is recommended following the patch to avoid recurrence.

PurposeTo study the distinct imaging characteristics of parenchymal neurocysticercosis (NCC) that aid in distinguishing it from other diseases.Material and methodsTwo hundred fifty patients with NCC were selected based on identification of the scolex. T2 weighted, T1 fluid attenuated inversion recovery (FLAIR), T2 FLAIR, susceptibility weighted imaging, constructive interference in steady state, diffusion weighted imaging, and T1 weighted contrast sequences were performed. The imaging characteristics of the cysts at various stages were analyzed.ResultsThis study presents previously undocumented imaging findings of NCC, establishing absolute, major, and minor criteria for its diagnosis based on magnetic resonance imaging features.ConclusionsUtilizing imaging criteria for diagnosing NCC, as per the study’s sequences, can effectively narrow down differential diagnoses and lead to accurate identification.

Department of Neuroradiology, Apollo Hospitals, Bengaluru, Karnataka, India Address for correspondence: Dr. Anvesh Apkari, Flat No 313, Autumn Block, Windsor Four Seasons, Bannergatta Road, Bengaluru – 560076, Karnataka, India. E-mail: [email protected]

Cochlear Implantation (CI) is a well-accepted treatment for severe-to-profound sensorineural hearing loss, refractory to conventional hearing amplification. Pre-operative Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) play pivotal roles in patient selection to rule out findings that preclude surgery or identify conditions that may impact the surgical procedure. A prospective study was carried out in a tertiary care center over three years, from January 2020 to January 2023. One hundred and ninety (380 ears) patients’ High-Resolution Computed Tomography (HRCT) studies of the temporal bone and MRI scans of the auditory pathways were analyzed. A reporting format was followed which was devised by a team of senior implant surgeons and senior neuro-radiologists. Our study aims to provide a comprehensive radiologic protocol for CI candidacy including normative data for the essential morphometrics in the Indian setting.

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS), classically presenting as a triad of early-onset cerebellar ataxia, lower extremity spasticity and peripheral neuropathy, is caused by mutations in SACS gene which encodes the protein sacsin. To provide new insight into the occurrence of SACS mutations in South India. Patients with three cardinal features of ARSACS—peripheral neuropathy, cerebellar ataxia, and pyramidal tract signs were included. Nine patients were clinically identified and genetically evaluated. Mutation screening of SACS by targeted sequencing of 40 recessive ataxia genes panel by next-generation sequencing was conducted. Additional investigations included magnetic resonance imaging (MRI), fundoscopy, optical coherence tomography (OCT) and nerve conduction studies (NCS). Functional disability was assessed by the Spinocerebellar Degeneration Functional Score. Two hundred and fifteen cerebellar ataxia patients were screened, and 9 patients with cerebellar ataxia with spasticity, peripheral neuropathy and MRI brain characteristics, consistent with a clinical diagnosis of ARSACS were identified, of which 7 patients were identified to have mutation in the SACS gene and are detailed hereafter. Age of presentation ranged from 20 to 55 years (29.8 ± 11.9) with a mean disease duration of 12.7 years (SD-7.65, range 5–22 years). All except one had onset of symptoms in the form of an ataxic gait noticed before 20 years of age. Additional features were subnormal intelligence (4/7), slow and hypometric saccades (1/7), seizures (1/7), kyphoscoliosis (1/7) and dysmorphic facies (1/7). SDFS was 3 in 5/7 patients signifying moderate disability with independent ambulation. MRI showed cerebellar atrophy with predominant atrophy of the superior vermis (7/7), horizontal linear T2 hypointensities in the pons(7/7), hyperintensities where lateral pons merges with the middle cerebellar peduncle (MCP) (7/7) well seen in fluid-attenuated inversion recovery (FLAIR) images, thickening of MCP (3/7), symmetric lateral thalamic hyperintensities (6/7), posterior fossa arachnoid cyst (4/7),thinning of posterior mid-body of corpus callosum (7/7), marginal mineralisation of the basal ganglia (7/7), bilateral parietal atrophy (7/7) and thinning of corticospinal tract on diffusion tensor imaging (DTI) (7/7). We identified pathogenic homozygous frameshift mutations in the SACS gene in six patients (including two siblings), while one patient had a heterozygous pathogenic deletion. This is the largest series of genetically confirmed ARSACS patients from India highlighting the clinical, ophthalmological, imaging and genetic features of this cohort.

Facial nerve schwannoma is a rare benign tumor of temporal bone arising from the schwann cells with incidence of 0.8%. They can arise from any segment of facial nerve with geniculate ganglion being the most common and labyrinthine segment the second commonest site. Intra-temporal location is common while only 9% of the cases have extra-temporal or parotid gland involvement. Bony remodeling or scalloping of the facial canal and the surrounding bone is the classic radiological feature of schwannoma. However schwannomas of temporal bone location can show bony erosions. The management option depends on site, extent, facial nerve function and hearing status. Surgery is reserved for large tumors with poor facial functions, hearing loss and giddiness. Giant facial nerve schwannoma with extra-temporal involvement is a rare entity with only handful number of cases reported in the literature. We present a series of two cases of giant facial nerve schwannoma with parotid gland involvement.

Background and Purpose: Leukoaraiosis is thought to be related to long-standing microvascular ischemia. The pathogenic mechanisms and hemodynamic changes could be different for periventricular and deep white matter leukoaraiosis. In this cross-sectional study, we examined whether the Pulsatility Index (PI) in Transcranial Doppler ultrasonography (TCD), which can give indirect information regarding downstream microvascular resistance and compliance, is different for leukoaraiosis in periventricular and deep locations. Correlation between presence of leukoaraiosis and PI was also studied since it was not studied in South-Asian patients before. Methods: Consecutive patients with suspected lacunar stroke or white-matter disease, undergoing MR brain imaging were included. Vascular imaging was done with CT or MR Angiography to rule out significant (>50%) stenosis. Fazeka's grading was done for severity of leukoaraiosis and mean PI in the middle cerebral artery (MCA) was obtained with trans-temporal TCD. Results: Ninety patients (Mean age 61 ± 10.9 years, 29% females) were available for final analysis. Age, hypertension, diabetes mellitus, CAD, and presence of leukoaraiosis were strongly associated with elevated mean PI in univariate analysis. In multivariate analysis, presence of leukoaraiosis was significantly associated with higher mean PI after adjusting for other variables. Mean PI strongly correlated with both periventricular (Spearman's correlation coefficient 0.56, P = 0.01) and deep white matter (Spearman's correlation coefficient 0.63, P = 0.01) leukoaraiosis. Conclusions: Our study confirms the correlation of Pulsatility Index with leukoaraiosis in South-Asian patients. Interestingly, changes in microvascular resistance appeared to be similar for both periventricular and deep white matter leukoaraiosis in spite of potential differences in etiopathogenesis.

BACKGROUND: Mucormycosis infection of the maxillofacial region and brain has been associated with coronavirus disease 2019 (COVID-19) infection. Mucormycosis was relatively a rare infection before COVID-19, and imaging findings are not very well described. MATERIALS AND METHODS: A retrospective imaging study of 101 patients diagnosed with COVID-19-associated mucormycosis by histopathology and/or culture was performed. All patients underwent computed tomography and/or magnetic resonance imaging based on the clinical condition of the patient and on consensus decision by the team of treating physicians. A simple 3-stage classification system based on imaging findings was adopted. RESULTS: One hundred one cases were included in the final analysis (mean age = 55.1 years; male/female ratio = 67:34). The affected patients had diabetes in 94% of the instances (n = 95), 80.1% (n = 81) received steroids), whereas 59.4% (n = 60) patients received supplemental oxygen. The majority underwent surgical intervention, whereas in 6 cases, patients were treated with antibiotic regimens. Sixty subjects improved following therapy, whereas 18 eventually succumbed to the illness. We noted a significant positive correlation between the imaging stage and outcomes. No association was seen between other clinical parameters and final clinical outcomes. Salient imaging findings include lack of normal sinonasal mucosal enhancement, perisinus inflammation, ischemic optic neuropathy, perineural spread, pachymeningeal enhancement, and presence of strokes. CONCLUSIONS: We describe the imaging findings in the largest cohort of patients with rhino-orbito-cerebral mucormycosis in the context of the current COVID-19 pandemic. A simplified staging system described here is helpful for standardized reporting and carries prognostic information.

Schwannomas are benign neoplasms arising from myelinating Schwann cells. Nerve sheath tumours arising from the sympathetic chain are very sporadic, with very few cases reported that presented with Horner’s syndrome. The authors describe its radiological and histological features and surgical management in this case report. A sixty-eight-year-old man presented with throat discomfort and hoarseness of voice for three months. He had a palpable mass on the left side in the submandibular region on neck examination. The patient had left recurrent laryngeal nerve palsy and Horner’s syndrome on general examination. MRI with contrast was performed to see the extent of the tumour. Exploratory cervicotomy was performed; the tumour was seen originating from the lower cervical sympathetic chain posterior to the carotid sheath. Histopathological examination confirmed the diagnosis of cervical sympathetic schwannoma. Cervical sympathetic schwannoma is a benign, slow-growing neoplasm with varied presentation. Presentation with Horner’s syndrome is a rare but reported presentation. Radiological imaging plays a vital role in the identification and surgical management. For symptomatic tumours, exploratory cervicotomy is the preferred approach for its wide exposure. Histopathological examination is confirmatory for the diagnosis.

Background: Revisional bariatric surgery is unavoidable in a proportion of patients. Despite its need, the development of this speciality has been hampered by its complexity and preferred delivery in institutional set ups. Although primary bariatric surgery can be delivered in the private sector; safety and feasibility of revisional bariatric surgery remains unexplored in this setting. Materials and methods: Patients undergoing revisional bariatric surgery following previous Laparoscopic Adjustable Gastric Band (LAGB) between 2008 and 2019 at a single private bariatric unit with a minimum follow up of at least 6 months were included. The primary aim was safety outcomes and 30-day morbidity. Results: 178 patients with BMI of 45.6 +/- 8.2 kg/m(2) underwent revisional bariatric surgery. One stage conversion was performed for 86.5% of the cases. At 9.5 +/- 5.3 months follow up, BMI and percentage excess BMI loss were 31.8 +/- 6.2 kg/m(2) and 62.6 +/- 40% respectively. There was no mortality, and the major complication rate was 2.8%. There was no statistically significant difference in the incidence of complications based on one-stage vs. two-stage conversion (p = 0.52). There were no differences in weight loss outcomes post-revisional surgery according to the indication for revision (p = 0.446) or weight loss following primary surgery (p = 0.12). Conclusion: Revisional bariatric surgery can be delivered safely in the private sector with good outcomes. One-stage conversions are feasible and do not detrimentally affect the morbidity of the procedure or the weight loss outcomes. More importantly, success following revisional surgery is independent of the indication for revision and weight loss outcomes following primary surgery.

IgG4 related disease (IgG4-RD) is a fibro-inflammatory disease, with tendency to affect any organ of the body. However, few cases affecting the skull base have been reported in literature. We report one such case in an elderly male, who presented us with a mass lesion in the skull base that mimicked nasopharyngeal malignancy. On thorough clinical history, examination, and investigations, IgG4 Related disease was diagnosed and treatment was started for it. The patient responded well to the treatment and is on follow up.

Objective: Parapharyngeal space contains intricate vascular anatomy (external and internal carotid arteries) that might be inadvertently injured during the dissection in this plane. None of the bony landmarks can be used during the transoral robotic surgery (TORS) radical tonsillectomy as these landmarks lie lateral to the internal carotid artery (ICA) and external carotid artery (ECA) in transoral approach. Our study aims to identify the safe surgical limits during the dissection of parapharyneal space in TORS radical tonsillectomy and to correlate the same with radiological study. Material and methods: Fifteen cadavers (30 head and neck regions) and 50 CT-Angiogram of neck (100 head and neck regions) were included in the anatomical and radiological study respectively. The vertical midpoint of anterior tonsillar pillar (palatoglossus muscle) was taken as the reference point and all the measurements were done at the level of reference point both for anatomical and radiological study. Distance between tonsillar fossa and ECA, distance between tonsillar fossa and ICA, relation between ECA and styloglossus and relation between ICA and stylopharyngeus at reference level were studied. Results: The mean distance of ECA from the tonsillar fossa at the reference point was 18.2 mm in the anatomical study and 16.2 mm in the radiological study. The mean distance of ICA from the tonsillar fossa was 23.4 mm and 23.3 mm in the anatomical study and radiological study. There was no significant difference between the anatomical and radiological findings for both the mean distance between ECA and ICA to the tonsillar fossa (p value was 0.45 and 0.30 respectively). ECA was located posterolateral to styloglossus in 24 cases (80.0%) and 79 cases (79.0%) in the anatomical and radiological study respectively. ICA was found posterolateral to stylopharyngeus in 21 cases (70.0%) and 69 cases (69.0%) in the anatomical and radiological study respectively. Conclusion: The muscular plane between styloglossus and stylopharyngeus can be used as an envelope to locate the ECA and ICA that lie medial to these critical vascular structures during TORS. We propose to divide the parapharyngeal space into two compartments (anterior and posterior) based on the surgical perspective of inside-out anatomy. The anterior compartment houses styloglossus muscle with ECA posterolateral to it and the posterior compartment has stylopharyngeus and ICA posterolateral to it.

Intraventricular cavernomas (IVC) are rare entities.We report a case of incidentally detected intraventricular cavernoma (IVC) in frontal horn of the lateral ventricle in which the diagnosis was established by typical magnetic resonance imaging (MRI) features.The patient has been kept on follow up as surgical resection is not recommended in asymptomatic cavernomas.IVC should be considered in differentials of intraventricular mass to avoid unnecessary invasive diagnostic procedures and ineffi cient management of this benign lesion.

Purpose: Response Evaluation Criteria in Solid Tumors (RECIST 1.1) is the gold standard for imaging response evaluation in cancer trials. We sought to evaluate consistency of applying RECIST 1.1 between 2 conventionally trained radiologists, designated as A and B; identify reasons for variation; and reconcile these differences for future studies. Methods: The study was approved as an institutional quality check exercise. Since no identifiable patient data was collected or used, a waiver of informed consent was granted. Imaging case report forms of a concluded multicentric breast cancer trial were retrospectively reviewed. Cohen's kappa was used to rate interobserver agreement in Response Evaluation Data (target response, nontarget response, new lesions, overall response). Significant variations were reassessed by a senior radiologist to extrapolate reasons for disagreement. Methods to improve agreement were similarly ascertained. Results: Sixty one cases with total of 82 data-pairs were evaluated (35 data-pairs in visit 5, 47 in visit 9). Both radiologists showed moderate agreement in target response (n = 82; kappa = 0.477; 95% confidence interval [CI]: 0.314-0.640-), nontarget response (n = 82; kappa = 0.578; 95% CI: 0.213-0.944) and overall response evaluation in both visits (n = 82; kappa = 0.510; 95% CI: 0.344-0.676). Further assessment demonstrated "Prevalence effect" of Kappa in some cases which led to underestimation of agreement. Percent agreement of overall response was 74.39% while percent variation was 25.6%. Differences in interpreting RECIST 1.1 and in radiological image interpretation were the primary sources of variation. The commonest overall response was "Partial Response" (Rad A:45/82; Rad B:63/82). Conclusion: Inspite of moderate interobserver agreement, qualitative interpretation differences in some cases increased interobserver variability. Protocols such as Adjudication, to reduce easily avoidable inconsistencies are or should be a part of the Standard Operating Procedure in imaging institutions. Based on our findings, a standard checklist has been developed to help reduce the interpretation error-margin for future studies. Such check-lists may improve interobserver agreement in the preadjudication phase thereby improving quality of results and reducing adjudication per case ratio.

AbstractThe authors present two cases of recurrence of traumatic carotid cavernous fistula (CCF) following complete exclusion by parent artery occlusion (PAO). In both cases, the fistula recurred through the development of indirect CCF and reconstitution of the occluded artery through the development of vasa vasorum or simple recanalization of the parent artery. The cavernous venous sac was patent in both cases. The patent cavernous sac along with the inflammatory or angiogenetic factors might have induced dural neovascularization leading to the development of indirect CCF. These factors along with ischemia of the arterial wall secondary to the steal phenomenon due to persistent shunt flow would have triggered the development of vasa vasorum. Thus the cavernous sac embolization may have to be considered in addition to PAO when PAO is planned as a therapeutic option for direct CCF.

Accurate identification of the epileptogenic zone is an important prerequisite in presurgical evaluation of refractory epilepsy since it affects seizure-free outcomes. Apart from structural magnetic resonance imaging (sMRI), delineation has been traditionally done with electroencephalography and nuclear imaging modalities. Arterial spin labelling (ASL) sequence is a non-contrast magnetic resonance perfusion technique capable of providing similar information. Similar to single-photon emission computed tomography, its utility in epilepsy is based on alterations in perfusion linked to seizure activity by neurovascular coupling. In this article, we discuss complementary value that ASL can provide in the evaluation and characterization of some basic substrates underlying epilepsy. We also discuss the role that ASL may play in sMRI negative epilepsy and acute scenarios such as status epilepticus.

A 39-year-old male presented with dystonia since 2010 involving both upper and lower limbs. He had undergone mitral valve replacement in the past (2009) for rheumatic heart disease with severe mitral stenosis. During the postoperative period, there was difficulty in weaning the patient from the ventilator. The patient developed ischemic acute tubular necrosis and hypoxic encephalopathy. Magnetic resonance imaging (MRI) of the brain done [Figure 1] as a part of the evaluation for dystonia in 2016 showed atrophy of the bilateral posteromedial putamen and mineralization on susceptibility-weighted imaging (SWI) [Figure 1c and d] with relative normal signal intensity of the basal ganglia on fluid-attenuated inversion recovery (FLAIR) and T1-weighted images [Figure 1a and b].Figure 1: (a) Axial fluid-attenuation inversion recovery (left), (b) T1 (right) images of the brain reveal normal signal intensity of the basal ganglia. (c) Susceptibility-weighted imaging (left) (d) phase image (right) of the brain reveals atrophy of the posteromedial putamen and blooming, appearing-like torch fireThere are diverse patterns of hypoxia-related brain injury which depends on the severity of hypoxia and maturation of the brain. In an adult, the posterior putamen, ventrolateral thalami, cerebral cortex (sensory motor and visual cortex), cerebellum, and hippocampi are sites which are most vulnerable to severe asphyxia. The selective vulnerability of these areas is due to the presence of postsynaptic glutamate receptors, which are in turn susceptible to glutamate excitotoxicity.[12] On imaging with MRI during the chronic stage, the involved areas appear hyperintense on T2 and FLAIR due to atrophy and gliosis. The posteromedial putaminal atrophy and gliosis on FLAIR resemble a torch fire with the posterior putamen constituting the handle, the rest of the putamen the flame and this appearance was described as torch fire sign by Thomas et al.[2] Our case shows a similar appearance of putamen on SWI with FLAIR showing a relatively normal signal intensity. SWI is sensitive in picking up the subtle deposition of paramagnetic substance or blood product in the infarcted tissue and also outlining the involved posterior putamen suggesting the etiology for dystonia which is due to hypoxic injury based on the typical imaging appearance. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

BACKGROUND AND PURPOSE: Tumefactive demyelinating lesions with atypical features can mimic high-grade gliomas on conventional imaging sequences. The aim of this study was to assess the role of conventional imaging, DTI metrics (p:q tensor decomposition), and DSC perfusion in differentiating tumefactive demyelinating lesions and high-grade gliomas. MATERIALS AND METHODS: Fourteen patients with tumefactive demyelinating lesions and 21 patients with high-grade gliomas underwent brain MR imaging with conventional, DTI, and DSC perfusion imaging. Imaging sequences were assessed for differentiation of the lesions. DTI metrics in the enhancing areas and perilesional hyperintensity were obtained by ROI analysis, and the relative CBV values in enhancing areas were calculated on DSC perfusion imaging. RESULTS: Conventional imaging sequences had a sensitivity of 80.9% and specificity of 57.1% in differentiating high-grade gliomas (P = .049) from tumefactive demyelinating lesions. DTI metrics (p:q tensor decomposition) and DSC perfusion demonstrated a statistically significant difference in the mean values of ADC, the isotropic component of the diffusion tensor, the anisotropic component of the diffusion tensor, the total magnitude of the diffusion tensor, and rCBV among enhancing portions in tumefactive demyelinating lesions and high-grade gliomas (P ≤ .02), with the highest specificity for ADC, the anisotropic component of the diffusion tensor, and relative CBV (92.9%). Mean fractional anisotropy values showed no significant statistical difference between tumefactive demyelinating lesions and high-grade gliomas. The combination of DTI and DSC parameters improved the diagnostic accuracy (area under the curve = 0.901). Addition of a heterogeneous enhancement pattern to DTI and DSC parameters improved it further (area under the curve = 0.966). The sensitivity increased from 71.4% to 85.7% after the addition of the enhancement pattern. CONCLUSIONS: DTI and DSC perfusion add profoundly to conventional imaging in differentiating tumefactive demyelinating lesions and high-grade gliomas. The combination of DTI metrics and DSC perfusion markedly improved diagnostic accuracy.