Objective: To delineate and differentiate between late subacute hemorrhage and intracranial lipomas in clinically available conventional and advanced MR sequences. Methods: Two cases of late subacute hemorrhage and two cases of intracranial lipoma were reviewed with CT scans and 3.0T scanner MRI. The sequences evaluated in MRI were T1-weighted (T1W) fast spin echo (FSE), T2-weighted (T2W) FSE, gradient echo T2*-weighted (GRE T2*W) images, diffusion weighted (DWI), apparent diffusion coefficient (ADC) and multivoxel spectroscopy. Results: Late subacute hemorrhage and intracranial lipoma have similar imaging features on T1W, T2W FSE with blooming artefact at the margins on GRE T2*W. However on GRE T2*W sequence, the central area of lipoma demonstrates low signal; while hemorrhage demonstrates high signal. In DWI, late subacute hemorrhage shows hyperintensity; while in lipoma there is loss of signal.
Conclusion: Awareness of the potential pitfalls in standard sequence are important, as these entities appear to have similar T1W/ T2W characteristic with blooming artefact on T2*W. Knowing the distinctive central signal intensity pattern on GRE T2W* and DWI is therefore essential to differentiate between these lesions as there are differences to their clinical management.
We present the case of a 14-year-old Malay girl with an ependymoma of the conus medullaris who presented to multiple general practitioner clinics with a 24-month history of chronic low back pain. The pain was symptomatically managed as a simple musculoskeletal pain and sciatica. Further imaging to aid diagnosis was delayed until the appearance of severe pain with neurological deficits. Magnetic resonance imaging revealed an enhancing spinal mass at L1 through L3, and histopathological investigations confirmed the grade II ependymoma according to the World Health Organization classification. She underwent gross resection of the tumor. After the surgery, she developed neurogenic urinary bladder and bowel, which required intermittent self-catheterization, intermittent enema use, and intensive physical therapy.
It has recently been recognized that the clinical course of coronavirus disease 2019 (COVID-19) and secondary organizing pneumonia (OP) tend to follow a subacute progression of respiratory illness. We present images of radiological progression of COVID-19 pneumonia and secondary OP.
A 14-year-old girl presented with encephalopathy, delirium and ophthalmoplegia following a 3day history of high-grade fever. Brain MRI on day 6 of illness showed diffusion restricted ovoid lesion in the splenium of corpus callosum. Dengue virus encephalitis was diagnosed with positive PCR for dengue virus type-2 in both serum and cerebrospinal fluid. She made a complete recovery from day 10 of illness. Repeat brain MRI on day 12 of illness showed resolution of the splenial lesion. Serial diffusion tensor imaging (DTI) showed normal fractional anisotropy values on resolution of splenial lesion indicating that MERS was likely due to transient interstitial oedema with preservation of white matter tracts. This is the first reported case of MERS following dengue virus infection. It highlights the usefulness of performing serial DTI in understanding the underlying pathogenesis of MERS. Our case report widens the neurological manifestations associated with dengue infection and reiterates that patients with MERS should be managed supportively as the splenial white matter tracts are reversibly involved in MERS.