Heterogeneity analysis of Gd-DTPA uptake: improvement in breast lesion differentiation.

PURPOSE: The aim of this study was to assess whether lesion heterogeneity through pixel-by-pixel analysis of contrast-enhanced MR parameter maps would improve breast lesion differentiation. METHOD: Forty-nine female patients with primary tumors of the breast were imaged using contrast-enhanced MRI. The rate of transfer of contrast medium between the lesion and plasma was calculated via compartmental modeling over semiautomatically delineated regions of interest. The distributions of transfer rate values were subdivided into 10 segments for each lesion. The rate of change of the statistical moments of the transfer rate measured over the 10 segments allowed a quantitative measure of heterogeneity. RESULTS: In this patient group of 25 malignant and 25 benign lesions, improved differentiation was achieved by using a measure of lesion heterogeneity. The sensitivity and specificity obtained were 88 and 88%, respectively, compared with 84 and 76% when using the mean value of the transfer rate coefficient. CONCLUSION: Pixel-by-pixel analysis of contrast medium transfer rate maps allows the examination of lesion heterogeneity and offers improved lesion differentiation. The new method used to quantify lesion heterogeneity relies on the manner in which the exchange rate parameter varies when calculated over different segments of the distribution.     

Mechanisms of COVID-19-induced kidney injury and current pharmacotherapies

The COVID-19 pandemic created a worldwide debilitating health crisis with the entire humanity suffering from the deleterious effects associated with the high infectivity and mortality rates. While significant evidence is currently available online and targets various aspects of the disease, both inflammatory and noninflammatory kidney manifestations secondary to COVID-19 infection are still largely underrepresented. In this review, we summarized current knowledge about COVID-19-related kidney manifestations, their pathologic mechanisms as well as various pharmacotherapies used to treat patients with COVID-19. We also shed light on the effect of these medications on kidney functions that can further enhance renal damage secondary to the illness.