Dandy Walker malformation

Findings

There is a large fourth ventricle which appears to be in continuation with a large posterior fossa cyst which follows CSF signal.

Differential Diagnosis:
- Arachnoid cyst
- Dandy walker variant
- Dandy walker malformation


Diagnosis: Dandy Walker malformation


Key points

Classic triad makes up the Dandy-Walker malformation
- Vermian agenesis
- Communicating with an enlarged 4th ventricle
- Posterior fossa enlargement

Dandy-Walker malformation may be isolated or can occur with other malformations of the brain.

Associated CNS abnormalities include
- Agenesis of the corpus callosum
- Lipomas
- Aqueductal stenosis
- Microcephaly
- Encephalocele

The Dandy Walker Spectrum represents a broad spectrum of cystic posterior fossa malformations.

These include (from most severe to least severe):
- 4th ventriculocele: DWM in which large posterior fossa cyst erodes occipital bone causing posterior outpouching of the cyst (encephalocele) through the occipital bone
- "Classic" Dandy Walker Malformation: Cystic dilatation of the 4th ventricle which opens dorsally to a variable sized CSF cyst which causes an enlarged posterior fossa and superiorly rotated hypoplastic vermian remnant; hydrocephalus is common
- Dandy Walker Variant: 4th ventricle opens to a smaller posterior cyst with partial rotation of the vermis, variable vermian hypoplasia; normal sized posterior fossa
- Persistent Blake Pouch Cyst: Open 4th ventricle communicates with persistent cyst that fails to regress and obliterates basal cisterns; normal vermis
- Mega Cisterna Magna: Enlarged cisterna magna, 4th ventricle is closed; normal vermis

DWM commonly presents with macrocephaly and bulging fontanel, 80% are diagnosed by 1 year of age. Early death is common.
Etiology is from hindbrain development arrest. No 4th ventricle outlet foramina are formed.
Associated with other CNS/extracranial abnormalities two-thirds of the time, such as craniofacial, cardiac and urinary tract abnormalities, polydactyly, orthopedic, and respiratory abnormalities
Treatment includes CSF diversion of hydrocephalus with VP shunt

Subacute combined degeneration

Findings

Figure 2 and Figure 4: Sagittal and axial T2-weighted images demonstrate symmetrical hyperintensity within the dorsal columns that is contiguous in length over several vertebral body lengths.
Figure 1 and Figure 3: Sagittal T1-weighted images pre and post-gadolinium demonstrate hypointense signal within the dorsal cervical spinal cord without enhancement.


Diagnosis: Subacute combined degeneration


MR findings in subacute combined degeneration include symmetrical increased signal intensity in T2-weighted sequences along the dorsal columns that is usually contiguous over multiple vertebral body lengths.
The differential diagnosis includes B12 deficiency with subacute combined degeneration, tabes dorsalis and vacuolar myelopathy in AIDS.

Vitamin B12 deficiency causes a wide range of neurological, hematological and gastrointestinal disorders. Subacute combined degeneration is one such neurological disorder that is characterized by symmetrical numbness, weakness and paresthesia. It most commonly results from pernicious anemia and is potentially reversible with B12 supplementation.

MR findings include symmetrical increased signal intensity on T2-weighted sequences along the dorsal columns that is usually contiguous over multiple vertebral body lengths. Lesions are iso or hypointense to the normal cord on precontrast T1-weighted sequences. There can be variable contrast enhancement. The differential diagnosis includes tabes dorsalis and vacuolar myelopathy in AIDS. These can be distinguished from other myelopathies on the bases of their symmetry and contiguous cord level involvement. They can be differentiated from each other on the basis of laboratory tests and clinical history.

Who wants to be an expert Radiologist?

This is nice quiz by medicexchange.com. All you have to do is answer a set of fifteen questions with interesting features like 'ask-peers' and '50-50' lifelines. Simply play and if you can reach the top position in the Hall of Fame and manage to stay there till the end of the month, you'll receive an iPod touch.

Available here-

Who wants to be an expert Radiologist?

PS-I played this yesterday and hurray got all correct!!

A Day of the Dead

If you are blog hopping for wanting to read amusing blogs, then skip this one and go to the neighboring blog instead.

I have warned you! And you still keep on reading!

Go away now!

Okay you are very hard-headed, eh? Since you are insistent, do not blame me. Because today, on account of November 1 being the Day of the Dead, I want to talk about Death. No nonsense. Just a casual talk about Death. Many people find it morbid talking about Death. Not me.

Here it is.

Death is the cessation of life. Meaning, when the cells in your body no longer function, that's it. You're dead. In a few hours your body will stiffen-Rigor Mortis, and in another few hours your body becomes cold. Don't worry, these things won't hurt--because you are already dead. And dead don't feel anything. That's the bonus.

The mortician arrives and he disembowels you. And your family pays him to do that. Sucks. The coffin maybe expensive bronze or cheap lawanit. It depends on the funds of your relatives--or more precisely, the funds you left your family with. If you are a rich Chinese, then your coffin maybe even be partially made of gold.

Meantime, you have the worse make-up in your life. And the worse hairdo. The dead don't get rebond, you know. Many times, while living, you hoped to have a complete make-over. Now you get it--when you're dead. Free. And people who look at you in the coffin will console your family that you don't look dead, you only look sleeping--which is the biggest lie in the world. No dead person looks sleeping unless he's wearing his favorite pajamas. In that case they should throw in a hug pillow as well.

Most likely, the dress you worn in your graduation will also be your dress in the coffin. Now isn't that wonderful?

Your family will look at you, tears in their eyes, as you lay inside the coffin. Flowers and bouquets start to gather near your coffin. You didn't like the smell of those while living. Why don't they just get artificial instead?

For three or four nights, you lie there dead while people around you are playing baraha, betting in Sakla, playing Tong-its, or playing stupid games. People are having fun while you lay stiff in a claustrophobic box with all these malignant flowers around you. Not to mention you're heavy make-up. Gaaaah! You want to wake up and tell the people to stop this idiocy and get it done over with quickly. But of course, you cannot wake-up because you are already dead.

The big day arrives. If you're a rich Chinese, then you get some paid people to wail for you. But if you're the average Filipino, you finally have the chance to ride in the most expensive car you've ever ridden--a Cadillac, complete with sound system. The sounds, however, is not your favored rock or heavy metal group, but some tenor from the 1930s. You finally enjoy being dead for the first time, not being able to hear that horrendous music.

Your funeral march is delayed by traffic, the traffic policemen are having siesta inside their air-conditioned car. But finally and eventually, your entourage arrives in the cemetery. If you are rich, you enter into a mausoleum. If you are the average dead, you either enter into a nitso, or lowered to a pit grave. A priest or pastor blesses you, says the most wonderful lies about you. Everyone agrees.

The lowering of your casket is the most dramatic scene--like the lowering of the curtain in a dramatic stage-play. Eventually, people begins to leave, says words of consolation to your relatives. They proceed to the restaurant to have a nice meal.

And you...you are left there alone..in a cold and lonely soil..But you have company..the ants and worms...they become your best friends as they turn you from a human corpse in to a soil fertilizer.

Happy Day of the Dead.

Arachnoid cyst with acute subdural hemorrhage

Findings

Large left frontal cystic lesion with thin septations and no enhancement. Unclear whether this lesion is intra-axial or extra-axial. No diffusion restriction (image not shown), no surrounding vasogenic edema. Also present is an acute right subdural hematoma caused by the patient's fall.

Differential diagnosis for the cystic lesion:
- Arachnoid cyst
- Ependymal cyst
- Glial cyst


Diagnosis: Arachnoid cyst. Acute subdural hemorrhage.


Key points

Arachnoid cysts are CSF containing cysts which are intra-arachnoid, and do not communicate with the ventricular system.
50-60% occur within the middle cranial fossa.
May arise as a developmental anomaly, or may be acquired as a complication of adhesions.
Small number are associated with neoplasms.
Walls of cyst are formed by splitting of the arachnoid membrane.
Usually asymptomatic. Can have headache or seizures.
The most effective surgical treatment appears to be excision of the outer cyst membrane and cysto peritoneal shunting.

Radiology Grand Rounds XVII

Here is a case of Pediatric Aneurysm for the Radiology Grand Rounds submitted by Dr MGK Murthy, Dr Sumer Sethi of Teleradiology Providers. Concept and Archive of the Radiology Grand Rounds is available at- Radiology Grand Rounds.

The incidence of congenital aneurysms in the general population is about 1-2%. Clinically, a ruptured aneurysm presents as sudden onset of severe headache. In cases of subarachnoid hemorrhages, the most common aneurysms are posterior communicating, 38%; anterior communicating, 36%; middle cerebral, 21%. These three locations account for 95% of all ruptured aneurysms. The basilar artery accounts for only 2.8% and posterior fossa aneurysms are even less common. Posterior fossa aneurysms are as such uncommon. PICA (Posterior inferior cerebellar artery) aneurysms are extremely rare. In this child we can see that aneurysm producing mass effect and no leak has occurred. The speciality of paediatric aneurysms are increased incidence in posterior fossa and a higher incidence of giant aneurysms (more than 2.5 cm diameter) and there is diversity of type and these are more often located in peripheral location . In this case of a eleven year old boy congenital saccular variety is possible.

Childhood intracranial aneurysms are exceedingly uncommon. Diagnosis of intracranial aneurysms in childhood may be difficult because of their infrequency and confusing clinical presentation. The first report of an aneurysmal SAH in a child was published in 1871 in the German pathology literature, when Eppinger detailed the case of a 15-year-old boy, a gymnast who collapsed while exercising. Postmortem analysis revealed an intracerebral hemorrhage associated with an aneurysm as well as a stenosis of the aorta. The development of contemporary neuroimaging has contributed greatly to the study, understanding, diagnosis, and treatment of pediatric intracerebral aneurysms. The emergence of CT and MR imaging studies obtained with contrast agents has allowed noninvasive, detailed characterization of aneurysms and the structures surrounding them.

Take Home Message-- Aneurysms unequivocally occur in children and cause SAH. Giant aneurysms and lesions in the posterior fossa are relatively more common in children than in adults. The termination of the CA and the ACA are disproportionately common sites of aneurysm formation in the anterior circulation of children. Traumatic and infectious aneurysms occur more frequently in children than in adults, but this may reflect a relative paucity of spontaneous aneurysms in children. Vasospasm occurs in children but appears to be better tolerated. Surgical outcomes in children appear to be moderately better than in adults.

Reference- Medscape ( Registration required). Intracranial Aneurysms

Also, the pioneering experience of Teleradiology Providers for an Indian Village settings has been accepted as a letter to editor in Radiology. Read the full text here-

Teleradiology: A Rural Indian Center's Pioneering Experience

I hope you enjoyed this edition of Radiology Grand Rounds submissions are requested for the next Radiology Grand Rounds posted every month last sunday. If you interested in hosting any of the future issues contact me at sumerdoc-AT-yahoo-DOT-com.

Some Things

There are times that we say things and we don't really mean it. Have you done it? I'm thinking of some things people said which I hope are really true. I mean, some people will tell you bullshit straight away. It may be the truth but they can hurt your feelings by becoming too honest. Well, here are some things which we hope are true, but--on second thought.... are they really true?

1. One Size Fits All (Really?)
2. Can I talk to you for a second? (Who talks with someone for a second?)
3. Oh you look gorgeous!
4. The check is in the mail (Serious?)
5. I'll be back in a minute
6. I promise to keep it a secret between the two of us
7. I love you
8. You're the best thing that's ever happened to me
9. You look younger everyday
10. Oh that's bullshit
11. I'll pay you before the deadline
12. You want? (offering an expensive chocolate)
13. You're great!
14. Wash and wear
15. Good morning
16. I'm sorry
17. I'll take care of you
18. I like your hair
19. You're a real friend!
20. Come on, this will change your life
21. I'm quitting (when?)
22. You're really cute on that dress
23. Come on, this is a chance in a lifetime!
24. Thank you very much, I appreciate it.
25. I can't live without you (I've heard this many times)
26. Let's meet at exact 9 am tomorrow
27. Wow you're a great cook!
28. Nothing matters to me except you...
29. You're mother is a great woman
30. Sure, go ahead and do what you want! (You're in serious trouble if you really did go ahead!)
31. Everything will be just fine
32. I believe you
33. Tomorrow will be better
34. This is outrageous! (looking at porno pictures in the internet)
35. You are the most wonderful person I've ever met (meaning, can you lend me 500 pesos?)
36. Come on, it will go away before you know it (talking about pimples)
37. You are my best friend
38. Very interesting
39. (On a personal ad in the net) Attractive young woman seeking soul mates (how can an attractive young woman be looking for geeks in the internet?)
40. This won't hurt (Dentist tells the patient)
41. I don't like sex