TIGHTEN YOURSELF TO ANSWER

Q.All are true regarding tight filum terminale syndrome except

a. Due to failure of complete involution of the distal cord

b. the filum thickness  greater than 2 mm in diameter

c. the tip of the conus medullaris lies below L-2

d.normal x ray of L/S spine

e. Filar fibrolipomas present in 29% of cases

ANS.---d

In a large series, 100% of cases had midline defects in the arches of the lumbosacral spine, usually at L-4, L-5, and/or S-1, leading to suggest that normal spine radiographs almost exclude this diagnosis.

?GYRAL CORE AND SULCAL ISLAND

Q.All are true regarding cortical tuber in tuberous sclerosis except

a. tuberlike, misshapen gyri

b.prone to calcification.

b.contain unusually large cells

c.the “gyral core” appearance on T2W and the “sulcal island” on T1W

d.only rarely show contrast enhancement 

e. seen in cerebellum

ANS.---c

The cortical tuber show  “gyral core” appearance on T1-weighted MR and the “sulcal island” on T2-weighted.

The characteristic gyral core is an isointense expanded gyrus of gray matter surrounding a central hypointense white matter center, and the sulcal island is both a geometric and signal intensity inversion of the gyral core—the subcortical white matter is abnormally bright and surrounds a sulcus with its gray matter borders of normal intensity

The abnormal hamartomatous tissue of the cortical tubers usually has prolonged T1 and T2, and so they are bright on T2-weighted images.

The abnormal hamartomatous tissue of the cortical tubers usually has prolonged T1 and T2, and so they are bright on T2-weighted images.

IS IT REALLY SMALL FINDING ?

:
Small bowel obstruction (SBO)

Conventional abdominal radiography is the preferred initial 

radiologic examination . Results of this technique are 

diagnostic in 50%–60% of cases; equivocal in about 20%–


30%; and normal, nonspecific, or misleading in 10%–20% . If 

the findings on plain radiographs are those of an unequivocal

 SBO pattern and a high-grade partial or complete SBO is 

suspected, immediate surgical evaluation should be 

performed 


Findings at Plain Abdominal Radiography

The key radiographic signs that allow distinction between a 

high-grade SBO and a low-grade obstruction are

1. the presence of small bowel distention, with maximal 

dilated loops averaging 36 mm in diameter and exceeding 

50% of the caliber of the largest visible colon loop as well as

 a 2.5 times increase in the number of distended loops in the

 abdomen compared with the normal number.

2. the presence of more than two air-fluid levels,

3. air-fluid levels wider than 2.5 cm, and air-fluid levels 

differing more than 2 cm in height from one another within

 the same small bowel loop 

 High-grade SBO. Plain abdominal radiograph shows multiple

 air-fluid levels (arrows), some with a width of more than 2.5

 cm. In addition, there is a differential vertical height of more

 than 2 cm between corresponding air-fluid levels in the 

same bowel loop (circled area). There is also distention of 

the small bowel diameter to more than 2.5 cm and a small 

bowel–colon diameter ratio of greater than 0.5.

ADAPTED FROM RADIOGRAPHICS

Diagnosis?

Q.A young patient undergoes MRI of brain which show no abnormality on unenhanced SE images. The pons reveals lacelike region of stippled contrast enhancement on contrast study .The patient is asymptomatic.The most likely diagnosis is
a.lymphoma
b.cavernous angioma
c.capillary telangiectasia
d.venous angioma
e.developmental venous anomaly
ANS.---c

The key to distinguishing the enhancement of capillary telangiectasia from other, similar enhancing lesions, notably lymphoma when periventricular, is the absence of any signal abnormality on the unenhanced images.

What is LINAC?

Q.All are true regarding treatment of AVMs except
a. untreated case shows grim prognosis
b. the goal of management is complete obliteration of the nidus for cure
c. the nidus less than 3.5 cm suitable  for radiosurgery
d. the effect of radiosurgery takes months to years
e. Endovascular treatment is usually primary treatment
ANS.---e
Endovascular treatment is usually an adjunctive measure to either surgery or radiation
Radiosurgery or stereotactic external beam radiation therapy uses focused irradiation directed at the AVM nidus. Radiosurgery is usually pursued in those cases considered unsuitable for resection because of either location of the AVM nidus or overall operative risk.

The efficiency of AVM obliteration is low when the AVM nidus exceeds 3.0 cm when treated with (radiation (“gamma knife”) or x-ray photon radiation (“LINAC radiosurgery”). Large AVMs greater than 3.0 cm may benefit from stereotactic heavy-charged-particle Bragg-peak radiation.

A linear accelerator (LINAC) customizes high energy x-rays to conform to a tumor’s shape and destroy cancer cells while sparing surrounding normal tissue

HAPPY CHRISTMAS TO ALL

HAPPY CHRISTMAS TO ALL

Yes---Enjoy the puff of smoke

Q.All are true regarding Moyamoya disease except
a. progressive symmetric occlusion involving the bifurcations of the internal carotid arteries (ICAs) and the proximal anterior and middle cerebral arteries
b. development of an extensive network of enlarged basal, transcortical, and transdural collateral vessels.
c. presence  of the expected flow void within the cavernous and supraclinoid portions of the ICAs
d. The angiographic appearance of the innumerable tiny collateral vessels, termed “puff of smoke” or “moyamoya” in Japanese.
e. Moyamoya disease has a bimodal age presentation, with the first peak occurring in the first decade of life, associated with cerebral infarction
ANS.—c
Moyamoya disease has a bimodal age presentation, with the first peak occurring in the first decade of life, associated with cerebral infarction as progressive carotid occlusion develops. Adult patients most often present in the fourth decade with intracranial hemorrhage arising from the rupture of the delicate network of collateral vessels

Absence of the expected flow void within the cavernous and supraclinoid portions of the ICAs is a consequence of narrowing and ultimately occlusion of these vessels

There is increased incidence of moyamoya changes in patients with Down syndrome.

Neural tube defect ---Pax,Drugs,?

738.All the drugs increase incidence of myelocele and myelomeningocele except

a. Phenobarbital

b.folate

c. phenytoin

d. carbamazepine

e. valproic acid

738.---b

Before 1980, myelocele and myelomeningocele occurred in 1 to 2 per 1,000 live births, up to 8 per 1,000 live births in specific populations . Since then, the incidence of these malformations has been reduced sharply (70% to 90%) simply by adding folate supplements to the diet of pregnant mothers in the period from before conception to 6 weeks after conception.

 Neural tube defects are known to be associated with disorders of maternal methionine metabolism and with elevated maternal levels of homocysteine.

Neural tube defects have also been related to derangements in the paired box gene Pax3(Waardenburg syndrome I on chromosome 2q35-q37.3)

Myelomeningocele may also be related to fragile X syndrome

What is sonic hedgehog (SHH)?

Q.All are true regarding molecular signaling in neurulation except

a. Hensen's node secretes molecules that lead to neural induction.

b. Noggin, follistatin, and chordin are neural inducers

c. BMP-4 promote  formation of neural ectoderm

d. the notochord  secretes the signaling molecule sonic hedgehog (SHH)

e. Floor plate produces SHH and the winged helix transcription factor hepatocyte nuclear factor (HNF)-3β

ANS.---c

The ventral mesoderm and the early ectoderm itself produce BMPs, especially BMP-4, which inhibit formation of neural ectoderm and promote differentiation of epidermal ectoderm.

RADIOLOGY MCQ---PERFUSION IMAGING

Q.All are true regarding perfusion imaging in mri except

a. dynamic susceptibility contrast (DSC) MRI is  most conventionally used to measure cerebral blood volume in brain .

b. dynamic contrast-enhanced (DCE) MRI  is used to measure vascular permeability in brain

c. MTT has been the most widely used parameter derived from DSC PWI

d. the k_trans value is putatively a measure of the vascular permeability to contrast agent

e. the k_trans correlates with glioma grade

ANS.---c

rCBV has been the most widely used parameter derived from DSC PWI

What is Barkhof and Tintore criteria?

Q.All are criteria for diagnosis of multiple sclerosis (Barkhof  and Tintore criteria) except

a.One gadolinium- enhancing lesion

b. seven T2-hyperintense lesions

c. At least one infratentorial lesion

d. At least one juxtacortical lesion (involving the subcortical U-fibers)

e.At least three periventricular lesions

162.---b

The Barkhof and Tintore  criteria  require three of four of the following findings  (a) One gadolinium- enhancing lesion, or nine T2-hyperintense lesions if there is no gadolinium-enhancing lesion. (b) At least one infratentorial lesion. (c) At least one juxtacortical lesion (involving the subcortical U-fibers). (d) At least three periventricular lesions.

RADIOLOGY MCQ ---Spondylodiscitis

Q.All are true regarding healing spondylodiscitis except

a. persistent disc space narrowing

b. decreased signal intensity of the disc on T2-weighted images

c. fusion of the adjacent vertebral bodies

d.resolution of the high signal intensity in the adjacent endplates

e. high signal intensity  from a previously infected vertebra on T1W

ANS.---e

The finding of high signal intensity on T1-weighted images  from a previously infected vertebra reflects replacement of cellular marrow by fat, indicating healing

RADIOLOGY MCQ---SPINAL CORD EPENDYMOMAS

Q.All are true regarding imaging of spinal cord ependymomas except

a. erosion of the pedicles or of the posterior surface of the vertebral bodies

b. typically heterogeneous on T2-weighted images

c.tend to enhance intensely but irregularly

d.  often have ill defined margin

e.areas of hemorrhage

ANS.---d

Although ependymoma are characteristically quite heterogeneous and astrocytomas are characteristically more homogeneous, it often is very difficult to differentiate these tumors from astrocytomas by imaging criteria. There are a few suggestive criteria, however.

First, ependymomas occur far more often in the lower cord and conus than astrocytomas.

Second, astrocytomas tend to arise eccentrically within the cord, especially posteriorly. Ependymomas arise from ependymal cells in the central canal and tend to be central

 Third, ependymomas are more frequently hemorrhagic than astrocytomas.

 Fourth, regions of low intensity reflecting hypercellularity are more common in ependymomas. Finally, because of the thin pseudocapsule that surrounds ependymomas, it may be possible on very thin sections to identify a plane separating the ependymoma from the cord, unlike astrocytomas, which tend to be infiltrative and have poorly defined borders.

MCQ -----Magnetization transfer

6.All are true regarding magnetization transfer sequences except

a.involves irradiating the tissue with off-resonance RF

b.a decrease in detectable water signal after the MTC pulse implies absence of macromolecules

c.may enhance the contrast obtained in imaging  intracerebral hemorrhage

d. may be useful in the detection of demyelination

e.useful in reducing background signals in MR angiography of the brain

6.----b

A decrease in detectable water signal after the MTC pulse implies

 a magnetization exchange, which further implies the presence of 

macromolecules. On the other hand, the absence of significant

 change in detectable water signal after the MTC pulse is applied

 implies an absence of macromolecules

RADIOLOGY MCQ ----ASPIRIN FOR NIGHT PAIN

Q.All are true regarding osteoid osteoma of vertebral spine except

a. The most common locations in the spine -- the lumbar region (59%)

b. Osteoid osteomas involve the posterior elements in 75% of cases.

c. presence of  the nidus (less than 1.5 cm)

d. focally “hot” on bone scan

e. no enhancement of  nidus

ANS.---e

Plain films   show a lucent nidus in classic cases . The size of the nidus is less than 1.5 cm (if greater than 1.5 cm, the lesion would be classified as an osteoblastoma),. The nidus is surrounded by sclerotic bony reaction

The administration of gadolinium, like that of iodinated contrast material, causes intense enhancement within the very vascular nidus. This enhancement may help not only to localize the nidus, but also to differentiate it from a nonenhancing lytic lesion such as Brodie's abscess .

RADIOLOGY MCQ ---HIV

Q.All are true regarding HIV encephalopathy except

a. occurs in patients with advanced immunosuppression

b. the cortex is preferentially affected 

c. the most distinctive microscopic ---Multinucleated giant cells 

d. The most common finding on imaging ---- atrophy of the brain

e. diffuse symmetric high signal intensity in the periventricular and deep white matter.

ANS.---b   

              

The central cerebral white matter and deep gray matter are 

preferentially affected, whereas the cortex is relatively spared