Monday, April 28, 2008

Radiology Grand Rounds XXIII



Here is a case of Cannavan's Disease for the Radiology Grand Rounds submitted by Dr Sumer Sethi of Teleradiology Providers. Concept and Archive of the Radiology Grand Rounds is available at- Radiology Grand Rounds.



Canavan’s disease
Deficiency of N- acetylaspartate cyclase enzyme – Increase in NAA.


"Canavan disease demonstrates bilateral symmetric T2 white matter hyperintensity, including involvement of the subcortical arcuate fibers. This disease appears diffusely throughout the cerebral white matter, does not enhance at computed tomography (CT) or MR imaging, and demonstrates variable involvement of the basal ganglia and cerebellar white matter. For example, both Canavan disease and Alexander disease demonstrate macrocephaly with bilaterally symmetric increased T2 signal intensity of cerebral white matter and involvement of subcortical arcuate fibers. MR spectroscopy, however, has been shown to be a useful diagnostic tool in making this distinction. There is an accumulation of NAA in patients with Canavan disease because of a deficiency in the myelin synthesis pathway; thus, MR spectroscopy reveals a markedly elevated NAA peak. "

In other white matter diseases there is Axonolysis hence NAA decreases, Defective myelination leads to increased Choline and lactate is seen in the activer disease.


Further reading (Radiology 2006;241:310-324.)


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.



Case by-Dr.Sumer K Sethi, MD
Consultant Radiologist ,VIMHANS and CEO-Teleradiology Providers
Editor-in-chief, The Internet Journal of Radiology
Director, DAMS (Delhi Academy of Medical Sciences)

Saturday, April 26, 2008

MR Spectroscopy in Meningioma

MR spectroscopy may provide additional information in cases in which the differential diagnosis
of tumors by neuroimaging is difficult. Cho reflects membrane turnover, correlates with malignancy in astrocytic tumors, and forms high peaks in meningioma. The most common proton spectrum found in meningiomas is a high Cho peak with low or absent NAA and Cr and variable amounts of lactate. Most important, an unusually high ratio of Ala to Cr has been found in meningiomas because of the high Ala and low Cr content, and this is a relatively specific finding for meningioma. Alanine is seen as doublet centered at 1.47 ppm and inverts on the long-TE sequence.

Reference- AJNR Am J Neuroradiol 20:882–885, May 1999

Saturday, April 05, 2008

Mesenchymal Hamartoma Shoulder-MRI



MR shows well defined heterogenous SOL in subacromial and superior aspect shoulder with no marrow oedema or joint involvemnt or rotator cuff involvement Smooth muscle hamartoma is an uncommon, usually congenital, cutaneous hyperplasia of the arrectores pilorum muscles. We report a case of this rare tumor in a 19-year-old man. The disease started several years ago as multiple small skin-colored papules that subsequently coalesced to form a large soft plaque on the back of the left shoulder. The diagnosis of acquired smooth muscle hamartoma was confirmed on histopathology. The patient was reassured about the benign nature of the lesion and was not advised any treatment.

Case by Dr MGK Murthy,Sr Consultant Radiologist

&

Dr.Sumer K Sethi, MD
Consultant Radiologist ,VIMHANS and CEO-Teleradiology Providers

Tuesday, April 01, 2008

Cysticercosis-MRI




Cysticercosis, or neurocysticercosis, is the most common parasitic infestation of the central nervous system worldwide. Humans develop cysticercosis when they ingest eggs or larvae of the tapeworm Taenia solium. The eggs and larvae are usually found in fecally-contaminated water and undercooked pork. The larvae of T. solium are able to invade tissue, and enter the bloodstream. From there, they are able to spread to many organs (skeletal muscle, heart, eye, brain, spinal cord) and form cysts in tissue called cysticerci. This case shows numerous cysts in all the paraspinal muscles and conus medullaris.


Case by-Dr.Sumer K Sethi, MD
Consultant Radiologist ,VIMHANS and CEO-Teleradiology Providers
Editor-in-chief, The Internet Journal of Radiology
Director, DAMS (Delhi Academy of Medical Sciences)

Dr Jaya Shankar, MD
Consultant Radiologist ,VIMHANS

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