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.
Magnetic Resonance Imaging

There are 50-100 million dengue infections each year, but dengue encephalitis is relatively uncommon. The aetiology of neuronal injury is proposed to be due to direct viral neurotropism or host immune response-mediated inflammation causing neuronal damage. We report a case of severe dengue encephalitis, presenting during the acute viraemic phase of the disease. This was associated with inflammation and haemorrhage of the internal medullary lamina of both thalami which, to our knowledge, has not yet been reported in other infections of the central nervous system.
Dengue

INTRODUCTIONThis study aimed to evaluate the vascular pattern of solid breast lesions using power Doppler ultrasonography (PDUS) and assess whether the presence of intratumoural penetrating vessels can predict breast cancer malignancy.

METHODSGreyscale ultrasonography (US) and PDUS were prospectively performed on 91 women in Malaysia with histopathologically proven breast lesions. The diagnostic accuracy of greyscale US, PDUS, and both greyscale US and PDUS was calculated and compared.

RESULTSThe 91 women had 102 breast lesions (55 benign, 47 malignant). Of the 47 malignant lesions, 36 demonstrated intratumoural penetrating vessels. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of greyscale US findings in diagnosing malignancy were 100.0%, 71.4%, 74.1% and 100.0%, respectively. The presence of calcification in the breast lesion and the margin, shape and posterior acoustic features of the lesion were significant parameters in predicting malignancy (p < 0.01). The sensitivity, specificity, PPV and NPV of the presence of intratumoural penetrating vessels in predicting malignancy were 76.5%, 80.0%, 76.5% and 80.0%, respectively. When both greyscale US and PDUS were used, there was a significant correlation in predicting malignancy (p < 0.05). The specificity and PPV values of the combined greyscale US and PDUS method (89.0% and 85.7%, respectively) were higher than those of greyscale US or PDUS alone.

CONCLUSIONFlow patterns revealed by PDUS can be useful for differentiating benign and malignant breast lesions. The visualisation of penetrating vessels in solid breast lesions can be used to complement greyscale US findings in predicting malignancy.

Adolescent ; Adult ; Aged ; Biopsy ; Breast Diseases ; diagnostic imaging ; Breast Neoplasms ; diagnostic imaging ; pathology ; Contrast Media ; Diagnosis, Differential ; Female ; Humans ; Malaysia ; Middle Aged ; Predictive Value of Tests ; Prospective Studies ; Reproducibility of Results ; Sensitivity and Specificity ; Ultrasonography, Doppler ; Ultrasonography, Mammary ; Young Adult