Icecream cone sign-
Normal appearance inco malleolar joint in axial CT section of epitympanum.
Intracanalicular extension of acoustic schwanoma giving the appearace of icecream cone.
CT reversal sign-
Relative reversal in attenuation between grey and white matter, supra and infratentorial structures. It is seen hypoxia, status epilepticus.
Mount Fuji sign-
Seen in bilateral subdural tension pneumocephalus. These air accumulations lead to compression in the frontal lobes and take a form of Mount Fuji on axial CT sections.
It is most commonly seen after surgical decompression of chronic subdural hematoma.
Lemon sign-
The lemon sign is seen in spina bifida. It is assosciated wtih chiari II malformations. Loss of normal convex contour of the frontal bones in transverse fetal sonogram obtained at biparietal diameter. It has a high sensitivity and
specificity in high risk patients beore 24th gestational week.
Pancake brain sign
Appearance of abonrmal brain tissue in cases of alobar holoproscencephly. The pancake brain sign is formed by fusion of cerebral hemispheres assosciated with the presence of typical monoventricle at the center.
Molor tooth sign
Joubert syndrome is an autosomal recessive disorder characterized by abnormal eye movements,nystagmus, and difficulty in following mobile objects with eyes, apnea-tachypnea episodes and motor retardation.
The posterior orientation of superior cerebellar peduncles in a way similat to stems of a molar tooth on axial CT or MR images.
Figure eight sign
Lissencephaly is a disorder caused by defective neuronal migration between 8-14th gestational week and characterized by a lack of devlopment of gyri and suci.
Face of gaint panda
It consists of high signal intensity of the tegmentum except for the red nucleus, preservation of signal intensity at the lateral portion of pars reticulata of the substantia nigra, and hypointensity of the superior colliculus.
Radial band sign
Linear or curvilinear areas with an abnormal signal intensity extending from the periventricular region to the subcortical region.
String sign/Tigroid appearance.
This sign is characterized by multiple dark spots or spots or stripes (spared perivascular white matter) of normal white matter intensity scattered within the bright demyelinated periventricular white matter on T2W images.
It is seen in Pelizaus- Merzbacher disease and metachromatic leukodystrophy.
Open circle sign
It is relatively specific sign for demyelination, helpful in distinguishing between ring enhancing lesions. Seen in patients with multiple sclerosis.
Key hole sign-
Seen in Dandy walker variant, there is a mild vermian hypoplastia and thus the vallecula becomes widened between the cerebellar hemisphere under the vermis.
This appearance is seen on acisl CT and MR images.
Cortical vein sign
It is used to differentiate extra axial subarachanoid and subdural effusions from each other. On both CT and MRI, briding veins extend from the cortical surface to the arachanoid. Appearance of bridging veins coursing in that manner in the extra axial fluid is called a positive cortical vein sign and indicated that the fluid is locaed subarachanoidally.
Caput medusa sign
The most common vascular malformation in the brain is venous angiomas. Most commonly observed in frontal lobes and in posterior fossa. It is also known a sa palm tree sign. It reers to number of veins drain centrally towards a single drain vein. The appearance is remimiscnet of Medusa, a gorgon of Greek mythology. the sign is seen on both CT and MRI when contrast i administered.
Angel wing sign
Chairi type II is the most common tyoe of Chiari malformation. It is also known as Arnold-Chiari malforamtion. In majority of cases associated with myelomeningocele, hydorcephalus, and carpus callosum agenesis.
Normal appearance inco malleolar joint in axial CT section of epitympanum.
Intracanalicular extension of acoustic schwanoma giving the appearace of icecream cone.
CT reversal sign-
Relative reversal in attenuation between grey and white matter, supra and infratentorial structures. It is seen hypoxia, status epilepticus.
Mount Fuji sign-
Seen in bilateral subdural tension pneumocephalus. These air accumulations lead to compression in the frontal lobes and take a form of Mount Fuji on axial CT sections.
It is most commonly seen after surgical decompression of chronic subdural hematoma.
Lemon sign-
The lemon sign is seen in spina bifida. It is assosciated wtih chiari II malformations. Loss of normal convex contour of the frontal bones in transverse fetal sonogram obtained at biparietal diameter. It has a high sensitivity and
specificity in high risk patients beore 24th gestational week.
Pancake brain sign
Appearance of abonrmal brain tissue in cases of alobar holoproscencephly. The pancake brain sign is formed by fusion of cerebral hemispheres assosciated with the presence of typical monoventricle at the center.
Molor tooth sign
Joubert syndrome is an autosomal recessive disorder characterized by abnormal eye movements,nystagmus, and difficulty in following mobile objects with eyes, apnea-tachypnea episodes and motor retardation.
The posterior orientation of superior cerebellar peduncles in a way similat to stems of a molar tooth on axial CT or MR images.
Figure eight sign
Lissencephaly is a disorder caused by defective neuronal migration between 8-14th gestational week and characterized by a lack of devlopment of gyri and suci.
Face of gaint panda
It consists of high signal intensity of the tegmentum except for the red nucleus, preservation of signal intensity at the lateral portion of pars reticulata of the substantia nigra, and hypointensity of the superior colliculus.
Radial band sign
Linear or curvilinear areas with an abnormal signal intensity extending from the periventricular region to the subcortical region.
String sign/Tigroid appearance.
This sign is characterized by multiple dark spots or spots or stripes (spared perivascular white matter) of normal white matter intensity scattered within the bright demyelinated periventricular white matter on T2W images.
It is seen in Pelizaus- Merzbacher disease and metachromatic leukodystrophy.
Open circle sign
It is relatively specific sign for demyelination, helpful in distinguishing between ring enhancing lesions. Seen in patients with multiple sclerosis.
Key hole sign-
Seen in Dandy walker variant, there is a mild vermian hypoplastia and thus the vallecula becomes widened between the cerebellar hemisphere under the vermis.
This appearance is seen on acisl CT and MR images.
Cortical vein sign
It is used to differentiate extra axial subarachanoid and subdural effusions from each other. On both CT and MRI, briding veins extend from the cortical surface to the arachanoid. Appearance of bridging veins coursing in that manner in the extra axial fluid is called a positive cortical vein sign and indicated that the fluid is locaed subarachanoidally.
Caput medusa sign
The most common vascular malformation in the brain is venous angiomas. Most commonly observed in frontal lobes and in posterior fossa. It is also known a sa palm tree sign. It reers to number of veins drain centrally towards a single drain vein. The appearance is remimiscnet of Medusa, a gorgon of Greek mythology. the sign is seen on both CT and MRI when contrast i administered.
Angel wing sign
Chairi type II is the most common tyoe of Chiari malformation. It is also known as Arnold-Chiari malforamtion. In majority of cases associated with myelomeningocele, hydorcephalus, and carpus callosum agenesis.