S evere acute respiratory failure is the dominant cause of death in patients with coronavirus disease 2019 (CO-VID-19) (1). The pathophysiology and imaging features of severe COVID-19 pneumonia have been the focus of considerable interest from the outset of the pandemic. In early disease, widespread ground-glass opacification predominates at thoracic CT (2-6) and is supposedly associated with highly compliant lungs and disrupted vasoregulation (7). Vascular dysregulation is believed to be consequence of exaggerated activation of inflammatory and coagulation cascades (termed immunothrombosis) (1,(8)(9)(10)(11)(12). Later in the course of disease, CT more commonly shows consolidation and fibrosis associated with lower lung compliance (13).There is growing evidence from radiologic and pathologic studies of a significant vasculopathy in COVID-19 pneumonia (14-17); in a recent study of postmortem lungs in COVID-19, there were widespread microthromboses and striking new vessel formation (16). Furthermore, based on qualitative analyses, a number of studies have highlighted the potential role of dual-energy CT pulmonary angiography (DECTPA) (15,(18)(19)(20)(21). Accordingly, in the present study, we aimed to evaluate the relationships between a quantitative measure of perfusion at DECTPA (relative perfused blood volume [PBV], ie, PBV relative to pulmonary artery enhancement [PBV/PAenh]) ( 22) and (a) disease duration, (b) right ventricular dysfunction (RVD) at echocardiography, (c) d-dimer levels, and (d) obstruction score (23) in patients with severe COVID-19 pneumonia. A secondary aim was to compare PBV/PAenh in COVID-19 pneumonia to that of healthy volunteers.
Background
Breast cancer is the most frequent cancer in women and remains the second leading cause of death in Western countries. It represents a heterogeneous group of diseases with diverse tumoral behaviour, treatment responsiveness and prognosis. While major progress in diagnosis and treatment has resulted in a decline in breast cancer-related mortality, some patients will relapse and prognosis in this cohort of patients remains poor. Treatment is determined according to tumor subtype; primarily hormone receptor status and HER2 expression. Menopausal status and site of disease relapse are also important considerations in treatment protocols.
Main body
Staging and repeated evaluation of patients with metastatic breast cancer are central to the accurate assessment of disease extent at diagnosis and during treatment; guiding ongoing clinical management. Advances have been made in the diagnostic and therapeutic fields, particularly with new targeted therapies. In parallel, oncological imaging has evolved exponentially with the development of functional and anatomical imaging techniques. Consistent, reproducible and validated methods of assessing response to therapy is critical in effectively managing patients with metastatic breast cancer.
Conclusion
Major progress has been made in oncological imaging over the last few decades. Accurate disease assessment at diagnosis and during treatment is important in the management of metastatic breast cancer. CT (and BS if appropriate) is generally widely available, relatively cheap and sufficient in many cases. However, several additional imaging modalities are emerging and can be used as adjuncts, particularly in pregnancy or other diagnostically challenging cases. Nevertheless, no single imaging technique is without limitation. The authors have evaluated the vast array of imaging techniques – individual, combined parametric and multimodal - that are available or that are emerging in the management of metastatic breast cancer. This includes WB DW-MRI, CCA, novel PET breast cancer-epitope specific radiotracers and radiogenomics.
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