Clinical features and radiological manifestations of COVID-19 disease.

Coronavirus disease 2019 (COVID-19) was discovered after unusual cases of severe pneumonia emerged in December 2019 in Wuhan Province (China). Coronavirus is a family of single-stranded RNA viruses. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted from person to person. Although asymptomatic individuals can transmit the virus, symptomatic patients are more contagious. The incubation period ranges from 3-7 d and symptoms are mainly respiratory, including pneumonia or pulmonary embolism in severe cases. Elevated serum levels of interleukins (IL)-2, IL-6, IL-7 indicate the presence of cytokine release syndrome, which is associated with disease severity. The disease has three main phases: Viral infection, pulmonary involvement, and hyperinflammation. To date, no treatment has proved to be safe or effective. Chest X-ray and computed tomography (CT) are the primary imaging tests for diagnosis of SARS-CoV-2 pneumonia, follow-up, and detection of complications. The main radiological findings are ground-glass opacification and areas of consolidation. The long-term clinical course is unknown, although some patients may develop pulmonary fibrosis. Positron emission tomography-computed tomography (PET-CT) is useful to assess pulmonary involvement, to define the affected areas, and to assess treatment response. The pathophysiology and clinical course of COVID-19 infection remain poorly understood. However, patterns detected on CT and PET-CT may help to diagnose and guide treatment. In this mini review, we analyze the clinical manifestations and radiological findings of COVID-19 infection.

The Multiple Faces of Nervous System Lymphoma. Atypical Magnetic Resonance Imaging Features and Contribution of the Advanced Imaging.

Primary central nervous system lymphoma (PCNSL) is an uncommon variant of extranodal non-Hodgkin lymphoma, which involves the brain, leptomeninges, eyes, or spinal cord without evidence of systemic disease. In addition to a detailed history and physical examination, the evaluation of patients suspected of having a PCNSL should include a contrast-enhanced magnetic resonance imaging. Occassionaly, PCNSL shows peculiarities on magnetic resonance imaging, which delay the diagnosis and thus the start of treatment. It is essential that radiologists be aware of these less common presentations such as isolated spine or meningeal lymphoma, angiocentric lymphoma, ocular lymphoma, and Epstein-Barr virus-associated lymphoma. Advanced neuroimaging (diffusion and perfusion sequences, spectroscopy-magnetic resonance, and positron emission tomography metabolic imaging) are useful techniques for the differential diagnosis of PCNSL with processes such as brain glioblastoma, multiple sclerosis, and metastases and brain abscesses, especially in atypical presentations. In this article, a review of unusual radiological findings for PCNSL in immunocompetent patients is made, highlighting the usefulness of functional and metabolic imaging for establishing an early presumptive diagnosis, which reduces delays in treatment.

Spontaneous skull base meningoencephaloceles and cerebrospinal fluid fistulas.

Cerebrospinal fluid (CSF) fistulas are characterized by the egress of CSF from the intracranial cavity through an osteodural disruption between the subarachnoid space and a pneumatized structure within the skull base. Depending on the cause, CSF fistulas are classified as acquired or congenital, and acquired fistulas are further classified as traumatic, nontraumatic, or spontaneous. Spontaneous CSF fistulas are considered to result from a multifactorial process and have been postulated to represent a variant of idiopathic intracranial hypertension. However, an anatomic predisposition involving thinning of the cranial base, such as pneumatization of the sinus walls, must also be present. This process creates areas of structural weakness that act as potential pathways for CSF leaks, which most commonly occur in the ethmoid roof, sphenoid sinus, and temporal bone. Because CSF leaks may be overlooked, a result of their asymptomatic or subtle, intermittent course, a high level of suspicion is crucial in making an early diagnosis. However, CSF fistulas may be well seen at computed tomography (CT), which depicts bone defects, and magnetic resonance cisternography, which reveals the contents of herniated tissue. Knowledge of the location and size of the bone defect and herniated contents is crucial for the selection of surgical approach and grafting material.

Kidney in danger: CT findings of blunt and penetrating renal trauma.

Approximately 10% of all significant blunt abdominal traumatic injuries manifest with renal injury, although it is usually minor. However, renal imaging is indicated in cases of gross hematuria, penetrating trauma with gross or microscopic hematuria, and blunt trauma and shock with gross or microscopic hematuria. Contrast material-enhanced computed tomography (CT) is the imaging modality of choice in the evaluation and management of renal trauma. Contrast-enhanced CT is readily available in emergency departments and can quickly and accurately depict renal injuries as well as associated injuries to other abdominal or retroperitoneal organs. In this way, contrast-enhanced CT provides the anatomic and functional information that is essential for accurate staging. In addition, CT can help detect active hemorrhage and urinary extravasation and is very useful in guiding transcatheter embolization and delineating preexisting disease entities that may predispose kidneys to posttraumatic hemorrhage. With the advent of multidetector CT, imaging is characterized by faster scanning times, increased volume coverage, and improved spatial and temporal resolution. The increased use of CT has been partially responsible for a growing trend toward conservative management of renal trauma, except in cases in which extensive urinary extravasation or devitalized areas of renal parenchyma are found and especially in those cases with associated injuries to other abdominal organs; these cases are particularly prone to complications and usually require surgery.