NOTCH THE ANSWER

Q.All are true regarding Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) except

a. manifest as subcortical dementia of the Binswanger type

b. the notch 3 gene involved

c. symmetric and confluent areas of high signal intensity on the T2 W in the subcortical and periventricular white matter

d. most lesions  in the occipital and parietal lobe

e.patients  typically younger than individuals with subcortical arterial sclerotic encephalopathy.

ANS.---d

Most lesions CADASIL are seen in frontal, temporal, and insular lobes.

HAPPY REPUBLIC DAY --INDIA

HAPPY 
             REPUBLIC 
                               DAY 

?para-anti-ferro-dia-super

Q.All substances enhances  the effective magnetic field B_eff except

a.paramagnetic

b.antiferromagnetic

c.ferromagnetic

d.superparamagnetic

e.diamagnetic

ANS.---e

Any material, when placed into a constant magnetic field, responds by generating its own magnetic field. The magnetic susceptibility of a substance (or tissue) describes this magnetic response. Diamagnetic materials respond to an applied field with a very weak induced field (approximately10^-6 × the magnitude of the applied field) and in a vector direction that opposes that of the applied field. Paramagnetic materials have a larger induced field (approximately10^-2 to 10^-4 × the magnitude of the applied field), which is in the same vector direction as the applied field. Superparamagnetic and ferromagnetic materials generate a very large induced field, equal to or even greater than the applied field, and, as with paramagnetic substances, the induced field is in the same vector direction as the applied field.

Diamanetic substance reduces  the effective magnetic field B_eff.

IS IT REALLY EMPTY?

Q.All are true regarding “empty sella turcica” except

a. severely flattened pituitary gland

b. the superior portion of the sella turcica filled with CSF

c. the diaphragma sella  thin

d. enlargement of the sella turcica

e.abnormally positioned stalk

ANS ---e

It is the deficiency of the diaphragma that is the primary defect in “empty sella turcica”. This allows the suprasellar cistern to herniate into the sella, exposing it to CSF pulsation and eventually resulting in enlargement of the sella turcica.

The only differential diagnosis is that of an arachnoid cyst occupying the superior portion of the sella turcica. It is important to determine the position of the pituitary stalk to distinguish these entities. In the empty sella, the stalk is normal in position, whereas space-occupying cysts cause it to be obliterated or displaced

? HEMICORD

Q.All are true regarding diastematomyelia except

a.coronal clefting of spinal cord

b.80 % cases in female

c.45% cases in lumbar/lumbosacral area

d. the smaller hemicord often lies ventral to the larger hemicord

e.conus medullaris usually low

ANS----a

Diastematomyelia signifies a sagittal clefting of the spinal cord, conus medullaris, and/or filum terminale into two hemicords

The two hemicords are each narrower than normal  and nearly always (91%) reunite distally into a re-formed cord below the cleft . In 30% of cases the hemicords are grossly asymmetric in size. When the hemicords are asymmetric, the cord above and below the cleft is usually asymmetrically smaller on the side of the smaller hemicord, and the smaller hemicord often lies ventral to the larger hemicord. The filum terminale is usually-perhaps always-thickened and may itself tether the reunited cord. Hydromyelia is present in up to 50% of cases of diastematomyelia. It may affect the cord above the cleft and extend into one or both hemicords

Technique for occult MS

Q. Which MR technique may be used to discern otherwise occult Multiple sclerosis disease in normal-appearing brain parenchyma?

a.MR spectroscopy

b.MT techniques

c. Diffusion-weighted MR imaging

d.T2W

e.T1W

ANS--.----b

MT techniques have been applied to brain MR in an attempt to characterize MS lesions and to discern otherwise occult disease in normal-appearing brain parenchyma.

This pulse sequence technique exploits differences in relaxation between immobilized water transiently bound to macromolecules and water protons not associated with macromolecules. The hypothesis underlying these investigations is that demyelination results in more free water (i.e., a reduction in the “bound” fraction of water) compared with myelinated white matter or intact but edematous tissue. Selective suppression of immobilized water is accomplished by the application of an off-resonance saturation pulse, which saturates the broad resonance of protons bound to macromolecules. Transiently bound protons exchange with free water protons by diffusion

 Using  experimental design, it has been shown in some studies that MT ratios are higher (i.e., there is more signal reduction due to the saturation pulse) in normal mature (myelinated) white matter than in gray matter. A slight decrease of the magnetization transfer ratio was noted in early inflammatory lesions without demyelination in models of experimental allergic encephalomyelitis. More pronounced reductions in MT ratios have been described in demyelinating lesions in experimental models (proportional to the degree of demyelination) and in patients with MS 

ALT--MAN ?

748.All are true regarding sacrococcygeal teratomas except

a.most probably derived from cells of Hensen's node

b.calcification  found in about 50% of benign teratomas

c.typically lie cephalic to the intergluteal cleft

d.Altman type I tumors  have minimal presacral component

e.mostly  mixed solid and cystic lesions

748.---c

Sacrococcygeal teratomas is the most common newborn tumor, the most common tumor of the sacrococcygeal region in childhood, and the most common sacrococcygeal germ cell tumor.

Most sacrococcygeal teratomas are visible externally (80% to 90%) Sacrococcygeal teratomas account for 25% of skin-covered lumbosacral masses  and typically lie within or below the intergluteal cleft .

 spinal lipomas nearly always lie cephalic to the upper end of the intergluteal cleft.

Grossly, sacrococcygeal teratomas are classified by their relationship to the skin surface and the pelvis .

Altman type I tumors (47%) lie predominantly external to the normal body and have minimal presacral component.

Altman type II tumors (35%) are evident externally but have significant intrapelvic extension. Altman type III tumors (9%) can be detected externally but lie predominantly within the pelvis and abdomen. Altman type IV tumors (10%) are entirely presacral.

BIG THANKS AND HAPPY NEW YEAR 2016

Thanks to all my friends.
Pageviews of my blog http://nagendraradiology.blogspot.in/ crossed FIFTY THOUSAND (50,000) on this last day of year 2015.
This happened all because of your support ,encouragement and healthy criticism
.I wish happy new year 2016 to all of you.

FIRST POST ON WEDNESDAY, 16 OCTOBER 2013
When you are inspired by some great purpose, some
extraordinary project, all of your thoughts break their
bonds: your mind transcends limitations, your
consciousness expands in every direction and you find
yourself in a new, great and wonderful world. Dormant
forces, faculties and talents become alive and you discover
yourself to be a greater person than you ever dreamed
yourself to be. (Patanjali)