Acute vertebral compression fracture: differentiation of malignant and benign causes by diffusion weighted magnetic resonance imaging

OBJECTIVE: To evaluate the sensitivity, specificity and accuracy of diffusion weighted (DWI) magnetic resonance imaging (MRI) in the diagnosis and differentiation between benign (osteoporotic/infectious) and malignant vertebral compression fractures in comparison with histology findings and clinical follow up. METHODS: The study was conducted at the Radiology Department, Aga Khan University Hospital (AKUH) Karachi. It was a one year cross-sectional study from 01/01/2009 to 01/01/2010. Forty patients with sixty three vertebral compression fractures were included. Diffusion-weighted sequences and apparent diffusion coefficient (ADC) images on a 1.5 T MR scanner were obtained in all patients to identify the vertebral compression fracture along with benign and malignant causes. Imaging findings were compared with histopathologic results and clinical follow-up. RESULTS: Diffusion-weighted MR imaging found to have, 92% sensitivity, 90% specificity and accuracy of 85% in differentiation of benign and malignant vertebral compression fracture while PPV and NPV were 78 % and 90% respectively. CONCLUSION: Diffusion weighted magnetic resonance imaging offers a safe, accurate and non invasive modality to differentiate between the benign and malignant vertebral compression fracture

Primary malignant melanoma of brainstem medulla mimicking as cavernoma

Aim of this case report is to present a rare case of primary malignant melanoma of brain stem at the region of medulla oblongata mimicking as cavernoma. 40-year-old male presented with vertigo, headache, dizziness for 1 month. MRI showed pear shaped T1 hyperintense lesion at medulla oblongata and predominantly hypointense on T2 with focal area of hemorrhage. Lesion showed diffuse enhancement on postcontrast images. On plain CT lesion was Hyperdense. It was initially reported as Cavernoma. Surgical excision of lesion was done with per-op findings of solid, dark maroon colored lesion with hemorrhage. Histopathology showed neoplastic lesion with abundant melanin pigment deposition. The lesion was finally diagnosed as Malignant neoplasm with features favoring Malignant Melanoma

Adult presentation of subacute necrotizing encephalomyelopathy in two siblings

Subacute necrotizing encephalomyelopathy (SNE) or Leigh syndrome is a rare progressive neurodegenerative mitochondrial disorder typically manifesting in the pediatric age group with variable clinical presentation and genetic heterogeneity. Late-onset varieties are extremely rare and only few cases have been reported globally. Neuroimaging however shows characteristic symmetrical necrotic lesions in the basal ganglia and/or brainstem. We report cases of two siblings who had history of seizures, but presented to us in adulthood. They had similar clinical presentation and radiological features on magnetic resonance imaging (MRI) and were subsequently diagnosed with SNE primarily based on imaging

Neuroimaging in Parkinson Disease

Over many decades, neuroimaging which included structural, functional and molecular modalities—have provided invaluable insights into the mechanisms underlying Parkinson disease (PD). These studies have shown changes in brain structure and metabolic activity. Although it is now considered to be complex, still neuroimaging modalities are recommended for routine use in clinical practice. Special sequences such as susceptibility weighted and proton density sequences are recommended for characterization. Now, the world is switching more towards the deep brain stimulation so the neuroimaging also helps in pretreatment planning and post treatment complications assessments. This chapter discusses the radiological anatomy, sequencing and imaging appearances. It will also discuss new approaches with potential applicability to clinical practice

Imaging patterns of encephalopathy in patients with COVID-19

The aim of this retrospective observational study was to describe the neuroimaging manifestations of patients with COVID-19. This study was conducted at Aga Khan University Hospital, Karachi, Pakistan from March to July 2020. COVID-19 patients with neurological symptoms and positive neuroimaging were included after confirmation of COVID-19 by polymerase chain reaction test (PCR). In the 12 included patients, seizures and altered mentation were predominant neurological manifestations. Three cases had acute watershed infarcts (25%), two cases had posterior cerebral artery territorial infarcts (16.7%), two cases had periventricular corona radiata infarcts (16.7%), three cases had hypoxic ischemic encephalopathy (25%), two cases had posterior reversible encephalopathy syndrome (16.7%), and there was one case each of cerebral venous sinus thrombosis, pontine infarct, and bithalamic lesions (8.3%). This study highlights the diagnostic approaches in COVID-19-associated encephalopathy and the variable imaging features that clinicians and neuroradiologists should be aware of, as the pandemic progresses. Key Words: COVID-19, Neuroimaging, Encephalopathy, Magnetic resonance imaging, Coronavirus

A rare case of melanotic schwannoma: Utility of susceptibility weighted sequences in preoperative imaging

Intracranial schwannomas account for 8% of all intracranial tumors, out of which 90% are acoustic schwannomas. Other rare varieties include trigeminal melanotic schwannomas that account for 0.2% of all intracranial tumors. Melanotic schwannomas are intracranial tumors that are heavily pigmented due to the presence of melanin. The most common origination of the tumor involves being confined to Meckel\u27s cave, presenting with features of trigeminal neuralgia, neurasthenia, and numbness. We report a case of a 48-year-old male presenting with dysarthria, left-sided hemiparesis, dysphagia, and headache for the past six months. Magnetic resonance imaging (MRI) confirmed a mass in the right cerebellopontine (CP) angle, which extended into the middle cranial fossa. Our case is interesting because it is the fourth case reported worldwid

Intramedullary cavernoma with extralesional haemorrhage

Intramedullary cavernomas are rare lesions constituting 5 to 12% of all intramedullary tumours. They are more recognized after introduction of magnetic resonance imaging and detection rates have improved by advance techniques. They may be solitary or multiple or may have associated cranial lesions. They may present with gradual neurological decline or with acute loss of spinal function. In addition neurological deficit depends on the location of the lesion within the spinal cord. We are reporting the case of a 45 year old male who presented with neck pain and progressive right arm weakness with numbness. MRI cervical spine with contrast showed intramedullary lesion with peripheral T2 hypointense rim and extralesional haemorrhage consistent with cavernoma. Patient underwent successful surgery and his symptoms markedly improved with mild residual grip weakness in right hand

MR perfusion imaging, techniques and role in differentiating radiation necrosis and tumor recurrence

High grade brain tumours are treated with surgery, chemotherapy and radiation therapy and despite such aggressive treatment, can recur in a short span of time. MRI scan has been the conventional diagnostic modality to diagnose recurrence, although at times it becomes difficult for the neuroradiologists to differentiate between tumour recurrence and radiation necrosis. Herein lies the emergent need to explore the efficacy of functional imaging to assist in this diagnostic challenge. Recent studies have sought to do so with promising implications, which we have attempted to summarize in this review

Diffusion-weighted magnetic resonance imaging may be useful in differentiating fungal abscess from malignant intracranial lesion: Case report

Background: Diffusion-weighted magnetic resonance has a well-defined role in differentiating between important intracranial lesions. Sometimes, the surgeon is faced with a dilemma of how to diagnose an infectious versus malignant lesion.Case Description: A 28-year-old male presented to the neurosurgery clinic with complaints of headache and left-sided weakness for 2 weeks. Neurological examination was intact. Magnetic resonance imaging (MRI) scan showed a large infiltrating heterogeneous mass involving the right parietal lobe. On further reviewing, there was homogenous diffusion restriction in the center of lesion. In addition, its aggressive behavior confirmed it to be a fungal abscess.Conclusions: Correctly identifying an infectious versus tumor etiology is important. Research has been carried out to employ diffusion-weighted imaging (DWI) in differentiating the variable radiological findings. The role of DWI in diagnosing bacterial abscess is more commonly seen in comparison to fungal abscess. DWI has a high diagnostic potential, but more works need to be done

Complications of ultrasound-guided liver biopsy at a tertiary care hospital in Pakistan: An audit

Introduction: Liver diseases account for two million deaths per year worldwide, half of which are attributed to complications of cirrhosis. Liver conditions have wide-ranging serological findings and imaging appearances and may require biopsy for a definitive diagnosis. Despite ultrasound (US) guidance, liver biopsy is an invasive procedure and the expected benefit must outweigh risks involved. Objective: The purpose of the audit was to calculate complication rates of US-guided liver biopsy and summarize institutional data pertaining to the procedure. Materials and Methods: The audit was performed at Aga Khan University Hospital, Karachi, Pakistan. All consecutive patients undergoing liver biopsy from February 2017 - February 2018 were included. Medical records of patients were reviewed for complications of liver biopsy. Results: The study population consisted of 157 adult and 21 pediatric patients. Complications were encountered in nine patients (5%), minor complications in seven (4%) and major complications in two (1.1%). Among the minor complications, haematoma formation was noted in four patients (2.2%), minor abdominal pain in two patients (1.1%), and minor hemorrhage during the procedure in one patient (0.5%). Minor complications were seen more frequently in pediatric (14%) patients as compared to adults (3.8%). One patient developed a major hemorrhage (\u3e 2 g/dl drop in hemoglobin (Hb)), and another patient developed severe vasovagal hypotension. There was no mortality in the study population resulting from complications of the liver biopsy. The audit standards set were met for all parameters, except major hemorrhage (\u3c 0.5%) which was narrowly missed (0.56%).Conclusion: US-guided liver biopsy at our institution has a good safety profile with complication rates within the expected range. Departmental practices are compliant with established practices and guidelines