Gastrointestinal Imaging Findings in the Era of COVID-19: A Pictorial Review.

The potentially fatal COVID-19 pandemic has been associated with a largespectrum of clinical presentations. Beyond the classical pulmonary manifestations, gastrointestinal tract-related symptoms suchas nausea, diarrhea, abdominal distention and pain have been observed in patients, as a consequence of the binding of SARS-CoV-19 to Angiotensin-converting Enzyme 2 (ACE2) receptors in the gastrointestinal (GI) tract. The early recognition ofspecific imaging features, including hepatobiliary involvement, pancreatic involvement, development of solid organ infarcts, ischemic bowel changes and vascular occlusion, plays a key role through the course of the disease. Also, suspicious symptoms, especially in critically ill patients with clinical and biochemical markers of hypovolemia, necessitate timely imaging for bleeding complications. The aim of this pictorial review is to illustrate the spectrum of the GIimaging findings in patients with COVID-19. Awareness of diagnostic imaging hallmarks is crucial to optimize the management of these patients.

The role of endoglin and its soluble form in pathogenesis of preeclampsia.

Preeclampsia remains till today a leading cause of maternal and fetal morbidity and mortality. Pathophysiology of the disease is not yet fully elucidated, though it is evident that it revolves around placenta. Cellular ischemia in the preeclamptic placenta creates an imbalance between angiogenic and anti-angiogenic factors in maternal circulation. Endoglin, a transmembrane co-receptor of transforming growth factor ß (TGF-ß) demonstrating angiogenic effects, is involved in a variety of angiogenesis-dependent diseases with endothelial dysfunction, including preeclampsia. Endoglin expression is up-regulated in preeclamptic placentas, through mechanisms mainly induced by hypoxia, oxidative stress and oxysterol-mediated activation of liver X receptors. Overexpression of endoglin results in an increase of its soluble form in maternal circulation. Soluble endoglin represents the extracellular domain of membrane endoglin, cleaved by the action of metalloproteinases, predominantly matrix metalloproteinase-14. Released in circulation, soluble endoglin interferes in TGF-ß1 and activin receptor-like kinase 1 signaling pathways and inhibits endothelial nitric oxide synthase activation, consequently deranging angiogenesis and promoting vasoconstriction. Due to these properties, soluble endoglin actively contributes to the impaired placentation observed in preeclampsia, as well as to the pathogenesis and manifestation of its clinical signs and symptoms, especially hypertension and proteinuria. The significant role of endoglin and soluble endoglin in pathophysiology of preeclampsia could have prognostic, diagnostic and therapeutic perspectives. Further research is essential to extensively explore the potential use of these molecules in the management of preeclampsia in clinical settings.

An off-label use of flow-diverter stent as a successful treatment of a postoperative middle cerebral artery pseudoaneurysm.

A pseudoaneurysm or false aneurysm is the result of the disruption of the vessel wall and the formation of a hematoma in communication with the vascular lumen, restrained by perivascular connective tissue. Intracranial pseudoaneurysms represent a rare entity mainly because of trauma, iatrogenic causes, infectious disease, radiation exposure, connective tissue disease and sometimes spontaneous occurrence. We present a 35-year-old female patient with a history of multiple low-grade glioma debulking surgeries. During the last procedure, laceration of the left middle cerebral artery (MCA) occurred with diffuse subarachnoid hemorrhage. Imaging studies showed the formation of a pseudoaneurysm of the left MCA which was successfully treated with the implantation of a flow diverter across the lesion neck and excellent mid- to long- term results. Flow diverter implantation may be a promising technique for the therapeutic management of cerebral pseudoaneurysms.

Advances in Noninvasive Carotid Wall Imaging with Ultrasound: A Narrative Review.

Carotid atherosclerosis is a major cause for stroke, with significant associated disease burden morbidity and mortality in Western societies. Diagnosis, grading and follow-up of carotid atherosclerotic disease relies on imaging, specifically ultrasound (US) as the initial modality of choice. Traditionally, the degree of carotid lumen stenosis was considered the sole risk factor to predict brain ischemia. However, modern research has shown that a variety of other imaging biomarkers, such as plaque echogenicity, surface morphology, intraplaque neovascularization and vasa vasorum contribute to the risk for rupture of carotid atheromas with subsequent cerebrovascular events. Furthermore, the majority of embolic strokes of undetermined origin are probably arteriogenic and are associated with nonstenosing atheromas. Therefore, a state-of-the-art US scan of the carotid arteries should take advantage of recent technical developments and should provide detailed information about potential thrombogenic (/) and emboligenic arterial wall features. This manuscript reviews recent advances in ultrasonographic assessment of vulnerable carotid atherosclerotic plaques and highlights the fields of future development in multiparametric arterial wall imaging, in an attempt to convey the most important take-home messages for clinicians performing carotid ultrasound.

Soluble endoglin concentration in maternal blood as a diagnostic biomarker of preeclampsia: A systematic review and meta-analysis.

OBJECTIVE: Preeclampsia is a main cause of maternal and fetal morbidity and mortality. Research about maternal circulating diagnostic biomarkers is continuously performed, often with conflicting results that necessitate quantitative synthesis. Objective of this meta-analysis is to examine the value of soluble endoglin as predictor of preeclampsia separately at each pregnancy trimester, therefore exploring its potential usage as diagnostic biomarker in preeclampsia. STUDY DESIGN: This systematic review and meta-analysis adhered to PRISMA and MOOSE guidelines. MEDLINE, SCOPUS, Cochrane CENTRAL and ClinicalTrials.gov were searched up to April 20, 2020. Included studies were those comparing soluble endoglin levels in maternal serum or plasma at any pregnancy trimester, between women who subsequently developed preeclampsia and normotensive pregnant women being low-risk for preeclampsia development. Primary outcome was development of preeclampsia, while soluble endoglin levels in 1 st, 2nd and 3rd trimester of pregnancy were examined as possible predictors of preeclampsia. Subgroup analysis was performed regarding time of preeclampsia onset (early, late). Methodological quality of included studies was assessed using Newcastle-Ottawa scale. Overall quality of evidence for primary and secondary outcomes was evaluated using GRADEpro GD tool. RESULTS: There were overall 20 studies included in meta-analysis, enrolling 1146 preeclamptic and 1675 normotensive pregnant women. Soluble endoglin concentration (ng/mL) was significantly higher in preeclamptic women during 2nd (8 studies, MD:5.554, 95 %CI:2.671-8.436, P < .001, I2 = 97 %) and 3rd trimester (12 studies, MD:31.006, 95 %CI:24.734-37.278, P < .001, I2 = 98 %). Levels were also higher during 1st trimester; however, the difference was marginally not significant (MD:1.105, 95 %CI: -0.071 to 2.282, P = .06, I2 = 64 %). Furthermore, levels were significantly higher both in early-onset and late-onset preeclamptic vs normotensive pregnancies, (4 studies, MD:51.611, 95 %CI:2.250-100.972, P = .04, I2 = 97 %), (5 studies, MD:12.426, 95 %CI:7.863-16.989, P < .001, I2 = 98 %) respectively. However, when comparing directly early and late-onset preeclamptic women, no significant difference was detected (3 studies, MD:20.725, 95 %CI: -11.601 to 53.052, P = .209, I2 = 93 %). CONCLUSIONS: Soluble endoglin levels were consistently higher in preeclamptic compared to normotensive pregnant women almost throughout pregnancy. Our results firmly indicate soluble endoglin's potential use as predictor of preeclampsia. Further studies are required to support the use of soluble endoglin as a diagnostic tool for preeclampsia in clinical settings.