Visual field defects are a conglomerate of patterns of visual impairment derived from diseases affecting the optic nerve as it extends from the globe to the visual cortex. They are complex signs requiring perimetry or visual confrontation for delineation and are associated with diverse aetiologies. This review considers the chiasmatic and post-chiasmatic causes of visual disturbances, with an emphasis on magnetic resonance imaging (MRI) techniques. Newer MRI sequences are considered, such as diffusion-tensor imaging. MRI images are correlated with perimetric findings in order to demonstrate localization of lesions in the visual pathway. This may serve as a valuable reference tool to clinicians and radiologists in the early diagnostic process of differentiating causes of various visual field defects in daily practice.
Complications of breast cancer metastasis may be the first manifestation of the disease. We report a rare case of left eye ptosis secondary to cavernous sinus syndrome in a 34-year-old lady due to refusal of proper medical treatment for metastatic breast cancer. The delay in seeking medical treatment was attributed to her use of Traditional Chinese Medicine (TCM).
A case of an intracerebral bleed in a young man with a rare combination of arteriovenous malformation (AVM) and unilateral moyamoya disease is presented. The location of the bleed in the left basal ganglia corresponded to the area supplied by the basal moyamoya vessels. The AVM which received supply from collateral moyamoya vessels as well as normal cerebral arteries was located in the ipsilateral parieto-occipital region posterior to the basal ganglia bleed. This is the first reported cerebral AVM co-existing with a unilateral moyamoya disease in the English literature. Unusual features of the case such as the unilaterality of the angiographic abnormalities, their coexistence and hypotheses as to their development are discussed.
The purpose of this review is to illustrate the differentiating features of multiple-system atrophy from Parkinson's disease at MRI. The various MRI sequences helpful in the differentiation will be discussed, including newer methods, such as diffusion tensor imaging, MR spectroscopy, and nuclear imaging.
To evaluate whether MR diffusion tensor imaging (DTI) of the optic nerve and optic radiation in glaucoma patients provides parameters to discriminate between mild and severe glaucoma and to determine whether DTI derived indices correlate with retinal nerve fibre layer (RNFL) thickness.
We report a rare case of a young boy presenting with bilateral blurring of vision following a viral like illness. Fundus examination revealed multiple pale cream-coloured lesions scattered across the posterior pole of both eyes. Fundus fluorescein angiography showed characteristic features of early hypofluorescence and late hyperfluorescence, further confirming the diagnosis of acute posterior placoid pigment epitheliopathy (AMPPPE). He was treated with topical steroids for the accompanying mild anterior uveitis. He had a prompt visual recovery with no adverse sequelae.
Despite technological advances in imaging, multiple sclerosis (MS) remains a clinical diagnosis that is supported, but not replaced, by laboratory or imaging findings. However, imaging is essential in the current diagnostic criteria of MS, for prediction of the likelihood of MS for patients with clinically isolated syndromes, correlation with lesion pathology and assessment of treatment outcome. This article gives an overview of imaging in MS with particular emphasis on the role of MRI in various diagnostic imaging criteria. Novel imaging for MS using 3 Tesla field strengths, magnetization transfer imaging, diffusion tensor imaging, magnetic resonance spectroscopy and cell-specific contrast will be reviewed.
Primary central nervous system (CNS) atypical teratoid/rhabdoid tumours (ATRT) are highly malignant neoplasms which usually present in infancy or early childhood. Although ATRT may arise anywhere within the CNS, the majority (approximately two-thirds) arise in the cerebellum or posterior fossa, and the remainder in the cerebrum. We described the imaging characteristics of CNS ATRT in the posterior cranial fossa of a 14-month-old boy.
Malignant osteopetrosis is associated with petrous carotid canal and internal carotid artery stenosis in the skull base. We present a four-year-old boy with malignant osteopetrosis who developed right frontal lobe infarction as a result of bilateral internal carotid artery hypotrophy.
Sarcoidosis is a multisystemic granulomatous disease of unknown aetiology mainly affecting African-Americans, Scandinavians, and the Irish. However, individuals of other races and ethnicities are still not immune. The clinical presentations vary widely with most patients having some respiratory problems. Though extrapulmonary sarcoidosis is no longer rare, sarcoidosis involving the lacrimal sac is an infrequently-reported problem. We present a case of sarcoidosis involving the lacrimal sac in a 42-year-old Malay woman who presented with epiphora. She was successfully treated with steroids and dacryocystorhinostomy. There was no evidence of systemic involvement. It is suggested that in an unusual presentation of sarcoidosis, a thorough search should be made for localisation of other sites, lungs in particular, even in the absence of respiratory complaints.
HBeAg and anti-HBe were determined in the blood of 189 male blood donors. The incidence of HBsAg was 6.9% while that for HBeAg and anti-HBe was 1.6 and 18%, respectively. Of the 13 samples positive for HBsAg, two (15.4%) were positive for HBe while six (46.2%) were positive for anti-HBe. One specimen was negative for HBsAg but was positive for HBeAg and anti-HBe. The observations are discussed.
This is a retrospective descriptive study of the chest imaging findings of 118 patients with confirmed A(H1N1) in a tertiary referral centre. About 42% of the patients had positive initial chest radiographic (CXR) findings. The common findings were bi-basal air-space opacities and perihilar reticular and alveolar infiltrates. In select cases, high-resolution computed tomography (CT) imaging showed ground-glass change with some widespread reticular changes and atelectasis.
We reported a case of pleomorphic adenoma of the lacrimal gland involving the palpebral lobe in young teenage girl of Asian origin. The presentation at young age group is rare, which initially misdiagnosed as a large chalazion. The benign tumor with its intact pseudocapsule was removed through lateral orbitotomy together with the suspicious looking orbital lobe.
Pre-natal diagnosis of intra-abdominal pregnancy is difficult. Ultrasound has been the frontline modality to date; however, it gives a diagnostic error of 50-90% and its use is disappointing. In recent years, MRI has emerged as an appealing imaging modality. With its good soft tissue contrast and non-ionizing property, it acts as a means of definitive non-invasive assessment before surgical intervention when ultrasound is inconclusive.
In the absence of raised intraocular pressure (IOP), haemodynamic parameters have been implicated in the development of normal tension glaucoma (NTG). The purpose of this study is to compare 24-hour IOP and haemodynamic parameters in NTG patients and non-glaucoma patients.
Identification of the epileptogenic zone is of paramount importance in refractory epilepsy as the success of surgical treatment depends on complete resection of the epileptogenic zone. Imaging plays an important role in the locating and defining anatomic epileptogenic abnormalities in patients with medically refractory epilepsy. The aim of this article is to present an overview of the current MRI sequences used in epilepsy imaging with special emphasis of lesion seen in our practices. Optimisation of epilepsy imaging protocols are addressed and current trends in functional MRI sequences including MR spectroscopy, diffusion tensor imaging and fusion MR with PET and SPECT are discussed.
Brown-Sequard syndrome (BSS) is a unilateral cord injury characterised by an ipsilateral motor deficit with contralateral pain and temperature hypoaesthesia. Although there are a variety of causes, the majority of cases are generally of neoplastic origin or are traumatic in origin. We describe a rare cause of Brown-Sequard syndrome as a result of post-traumatic arachnoiditis. Magnetic resonance imaging with the use of thin-slice high-resolution constructive interference in steady state (CISS) and T2-weighted spin-echo sequence were used to demonstrate the cause and appearance of the lesion in the spinal canal and was useful in the assessment and management of the patient. This case illustrates the usefulness of the CISS sequence in MRI for elucidating arachnoiditis.