Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

2,706 results found

Yin-yang sign (solitary fibrous tumor)

The yin-yang sign is a radiologic appearance described in solitary fibrous tumor of the dura on MR. On T2-weighted images, these tumors have two separate solid components, one that is hyperintense and one that is iso- to hypointense relative to brain parenchyma. Histologically, the former repre...

Y sign (epidural lipomatosis)

The Y sign refers to a common appearance in lumbar epidural lipomatosis where excess fat in the extradural space compresses the dural sac into the shape of the letter "Y". NB: Y sign also refers to the appearance of incudomalleolar disarticulation on CT, more commonly known to radiologists as t...

Zabramski classification of cerebral cavernous malformations

The Zabramski classification of cerebral cavernomas has been proposed as a way of classifying cerebral cavernous malformations, and although not used in clinical practice it is useful in scientific publications that seek to study cavernous malformations. The classification was proposed in 1994 ...

Zebra sign (cerebellum)

The zebra sign has been termed to describe the finding of layering of blood in amongst the folia of the cerebellum, particularly in the setting of supratentorial surgeries (temporal lobe resection), neuro-vascular neck surgeries, lumbar spinal surgeries possibly secondary to dural tear and inter...

Zellweger syndrome

Zellweger syndrome (ZS), also known as the cerebrohepatorenal syndrome, is a multisystem metabolic abnormality. As the name implies it primarily affects the central nervous system, liver and kidneys.  Epidemiology The condition typically presents in neonates with poor feeding and/or seizures. ...

Zika virus infection

Zika virus infection is a zoonosis which is associated with congenital birth defects, with microcephaly the most widely known. Epidemiology Zika was once isolated to Africa and Asia, however, it spread to the Americas in the last decade 1. There were thousands of cases confirmed in the America...

Zimmerman-Laband syndrome

Zimmerman-Laband syndrome is a rare congenital syndrome, characterized primarily by gingival hypertrophy and skeletal abnormalities.  Pathology The molecular basis of the syndrome is currently unknown. An autosomal dominant mutation with a high mutation rate and rare instances of germinal mosa...

Zinc toxicity

Zinc toxicity (also rarely known as zincalism) is rare as the body is remarkably efficient at excreting excess zinc. Typically oral zinc poisoning manifests primarily as: acute GI symptoms: vomiting, diarrhea, abdominal pain secondary copper deficiency zinc competes with copper for absorption...

Zurich pituitary score

The Zurich pituitary score (ZPS) is a quantitative classification of pituitary adenomas based on coronal T1W magnetic resonance imaging with contrast, although the score can also be obtained with computed tomography. The ZPS is based on the ratio (R) between horizontal tumor diameter over inter...

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.