Monday, December 31, 2007

Occlusion of the left internal carotid artery with subsequent large left MCA acute infarction








Findings

CT head demonstrates increased density of the left MCA, compatible with a dense MCA sign. Additionally, there is subtle hypodensity of the left lentiform nucleus and left sub insular cortex. MR head demonstrates restricted diffusion in a left MCA distribution. MR angiography demonstrates absence of flow in the left internal carotid artery and left middle cerebral artery.


Diagnosis: Occlusion of the left internal carotid artery with subsequent large left MCA acute infarction


Key points

Cerebrovascular infarction most commonly involves the MCA distribution.
Ischemic stroke is far more common than hemorrhagic stroke, accounting for approximately 85% of cases.
Third leading cause of death in the United States.
Non-contrast head CT is the initial study of choice to evaluate for signs of hemorrhage.
Therapeutic window for t-PA (tissue plasminogen activator) thrombolysis is 3 hours from symptom onset.
Non-contrast CT usually is negative within the first 6 hours of onset. From 6-12 hours, sufficient tissue edema occurs to cause regional hypodensity.
Diffusion-weighted MRI can show changes of ischemic stroke in as little as 30 minutes after symptom onset.
Signs of MCA infarction include the dense MCA sign, and insular ribbon sign.

Sunday, December 30, 2007

Radiology Blog-now four years old


Wishing all our readers of this blog a very happy and prosperous new year 2008. The concept of this blog is to provide and discuss radiology related information and has been doing so for last four years (since 2004). I welcome all our readers to actively participate by commenting on the cases and submitting their own radiology related experiences.

Our sister concern- Teleradiology Providers

Pilocytic Astrocytoma- MRI Findings




"Four predominant imaging patterns of pilocytic astrocytoma have been described: (a) mass with a nonenhancing cyst and an intensely enhancing mural nodule, (b) mass with an enhancing cyst wall and an intensely enhancing mural nodule, (c) necrotic mass with a central nonenhancing zone, and (d) predominantly solid mass with minimal to no cystlike component. Although most cyst walls do not enhance, some may enhance intensely, even as much as the mural nodule; however, cyst wall enhancement is not necessarily indicative of tumor involvement . Beliefs vary among neurosurgeons regarding whether to resect the cyst itself in cases of pilocytic astrocytoma. Some advocate complete resection, others biopsy, and still others no resection . Removal of the cyst wall has not been linked with improved survival ."


Case submitted by

Dr MGK Murthy, Dr Sumer Sethi


Friday, December 28, 2007

Recto Views from the moving LRT train


(Click the play button and wait a few minutes to download)

I'm really glad that Blogger now adds a video feature in their menu list, which means having to avoid Youtube as the host of videos. That means Bloggers just have to stick to Blogger for all their video needs, and not stray away into Youtube. Now, that's clever!

Actually, a few months ago, I was thinking of moving house from Blogger to either Wordpress or Multiply, since some of my online friends have account there. But I always find Blogger easier to use. I also have more friends in Blogger, and so moving house isn't really a necessity. Besides, The format of Blogger is also simpler, allowing posters and readers easy navigation within the site. Anyway that's my opinion, and so, I'll just stick to blogger to host my idiosyncracies and what-not. Blogger is giving an excellent service, and so I'll stay loyal and remain a true Blogger fanatic. (Attention Blogger: You should now give me an advertising fee)

Anyway, I want to test Blogger's video feature, and so I'm uploading here a recent video of Recto views from the moving LRT train. There are several amateur videos of Recto in Youtube, but all are shot from the ground. Mine is shot right from the moving train. I shot this on December 2007, while riding from Cubao to Recto. I hope you will feel you were riding with me in the LRT 3 through this video of mine. It is only a short video (basically because I just want to test Blogger video).

Shooting amateur videos is one of my favorite hobbies (besides photography). I have several amateur videos in my collection from the places I visited and I plan to post them all here soon. I only have my Sony DSC-T9 with me shooting these small amateur videos, but I plan to purchase an entry-level video cam early next year.

HAPPY NEW YEAR TO BLOGGER.COM!

HAPPY NEW YEAR TO ALL!

Tuesday, December 25, 2007

Social Networking for Radiologists

Just came across a new site radRounds which seems like a Facebook counterpart for a Radiologist with a aim of linking radiologists to each other and new opportunities in radiology. Seems like a great idea. Must check.

For Radiology Outsourcing--

Saturday, December 22, 2007

Radiology Grand Rounds XIX




Here is a case of Glomus Jugulare 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.


Glomus tumours
Synonyms are paragangliomas and chemodectomas
Location is usually jugular bulb, middle ear, carotid body, vagus nerve, periaortic, larynx, ciliary ganglion, mandible, nose and fallopian canal


Origin is embryonic neuroepithelium in close association with autonomic nervous system
4% are functional
4% are metastatic
Mostly benign and hypervascular



Imaging
CT findings
-destruction, expansion, involvement of sites as mentioned above no soft tissue component, intense enhancement with salt and pepper appearance.
MRI shows better delineation of characteristics, extent across CV junction, encasement of vessels, involvement of cranial nerves and IAM as well as intracranial extent


Treatment is controversial
For a small lesion may be only radiosurgery
For a bigger lesion combination of surgery with radiation


The Glasscock-Jackson and Fisch classifications of glomus tumors are widely used. The Fisch classification of glomus tumors is based on extension of the tumor to surrounding anatomic structures and is closely related to mortality and morbidity.
Type A tumor - Tumor limited to the middle ear cleft (glomus tympanicum)
Type B tumor - Tumor limited to the tympanomastoid area with no infralabyrinthine compartment involvement
Type C tumor - Tumor involving the infralabyrinthine compartment of the temporal bone and extending into the pterous apex
Type C1 tumor - Tumor with limited involvement of the vertical portion of the carotid canal
Type C2 tumor - Tumor invading the vertical portion of the carotid canal
Type C3 tumor - Tumor invasion of the horizontal portion of the carotid canal
Type D1 tumor - Tumor with an intracranial extension less than 2 cm in diameter
Type D2 tumor - Tumor with an intracranial extension greater than 2 cm in diameter


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.

Images Courtesy

Maligayang Pasko Po!

Maligayang Pasko Po!

I was thinking of giving each of you a gift (say a book or a t-shirt) but yesterday, I heard the mass, and the homily of the reverend says that gifts should not necessarily mean material things, but most importantly, a gift of love, thought, and prayers.

I am therefore giving you this year a gift of love, thought, and prayers--may you have peace and happiness this Christmas, now and forever.

I'm also greeting my Filipino online friends abroad who would not be with their families in the Philippines this Christmas. I know how you wish to return, and how you longed to be with your families here and spend the truly unique Filipino Christmas. And so, I just want to share with you some of the images of Philippine Christmas through my pictures.

Through my photographs, I can share with you--at least visually-the Christmas you really want to experience--our own Pinoy Pasko.


The traditional Parol is a lovely ornament to add to the joyful Philippine Christmas ambience.



Rush Christmas shopping in the bangketa of Carriedo (ingat din sa mandurukot at magnanakaw, namamasko rin kasi sila kahit di ninyo alam)



Chestnuts roasting on an open drum


Avenida Rizal


The excellent Hamon Excellente (cheap at 550 pesos per kilo)


Ahhh traffic!!!! (Hirap pa sumakay! Tapos yung mga taxi draybers ang yayabang- ayaw magsakay pag malayo.)


Parol and Christmas lights stores in Cubao (Be sure na ang bibilhin ninyo ay original para iwas sunog! Tip: Wag bumili ng Made in China)



Santa-curity Guards of Farmers Cubao



Rush hour. Last minute Christmas shopping




Tiangge



Christmas Sale daw



Simbang Gabi (para sa matatanda) , Simbang Porma (para sa mga fashionista), Simbang Ligaw (para sa mga nanliligaw)



Keso de Bola (Masarap, maganda tingnan, at higit sa lahat, mahal!)



No more money

Friday, December 21, 2007

Review of 2007

It's not even over yet....but JibJab's found enough stuff to make a pretty funny review of 2007. Also, JibJab has a new feature that allows you to cut out the heads on your digital pictures and use them in their videos. Check out the 2007 Review:

Fusiform basilar artery aneurysm









Findings

CT shows a basilar artery aneurysm at the level of the pons. Subtle calcification is present within the aneurysm wall (Figure 1 and Figure 2).

Axial GRE (Figure 5), T1 sagittal (Figure 3), T1 post gadolinium axial (Figure 6), and T2 axial (Figure 4) demonstrate a fusiform aneurysm of the mid to distal basilar artery that does not involve the basilar tip. An area of slightly increased signal intensity within the aneurysm suggests thrombus formation (blue arrow in Figure 4 and Figure 6). No subarachnoid space or fourth ventricle hemorrhage is present.


Diagnosis: Fusiform basilar artery aneurysm


Basilar artery aneurysms comprise approximately 10% of all intracranial aneurysms. Fusiform aneurysms comprise only 1% of vertebrobasilar aneurysms. The fusiform aneurysm is a long segment of irregular fusiform or ovoid arterial dilatation. It is more common in the vertebrobasilar circulation than in the carotid circulation. In older adults, atherosclerosis is the most common cause of fusiform aneurysms in the basilar artery. Nonatherosclerotic fusiform aneurysms usually occur in younger patients with underlying vasculopathy or immune disorders. Fusiform aneurysms usually progressively enlarge over time. The pathologic etiology of fusiform aneuryms is partial or total absence of the internal elastic lamina and/or media, either congenital or acquired, which reduces elastic wall tension and allows subsequent expansion of the vessel diameter over time.

The saccular aneurysm is a focal dilatation of the arterial wall. The pathogenesis of saccular aneurysms reflects a combination of congenital, acquired, and hereditary factors. Large (>5 mm) aneurysms are found in 5% of the population, characteristically distributed at the arterial bifurcations. Association with polycystic kidney disease, Ehlers-Danlos syndrome, and other connective tissue disorders implicates hereditary factors.

Most intracranial aneurysms (~90%) are saccular and arise in the carotid circulation. 30-35% of aneurysms arise from the anterior communicating artery, 30-35% from the posterior communicating artery origin, 20% from the middle cerebral artery bifurcation, 5% from the basilar artery bifurcation or tip and the remaining 1-5% arise from other posterior circulation vessels. Intracranial aneurysms are multiple in 15-20% of cases. 80-90% of nontraumatic subarachnoid hemorrhage (SAH) is due to aneurysms. The risk of bleeding is approximately 2.5% per year for lesions >6mm in diameter. Complications of SAH include hydrocephalus, rebleeding, and vasospasm.

On non-enhanced CT, the aneurysm is hyperdense, and calcification in the wall may sometimes be detected. Aneurysmal SAH may be detected in 90-95% of cases on non-contrast head CT. CTA may detect aneurysms greater than 3 mm, providing detailed evaluation of morphology such as the relationship to the parent vessel and the neck width. CTA can detect more than 95% of aneurysms identified on conventional angiography. MRI demonstrates variable signal on T1 weighted images, hypointense lumen and clot on T2 weighted images, and strong enhancement of the residual lumen on post-contrast T1 weighted images. CTA or dynamic contrast-enhanced 3D-TOF MRA are the studies of choice for evaluation as non contrast 3D-TOF images are suboptimal due to flow saturation and phase dispersion. Conventional angiography is the definitive procedure for the detection and characterization of cerebral aneurysms. Aneurysm location, size, and morphology may be evaluated in the acute or chronic setting with this modality.

Management of fusiform aneurysms is difficult due to their morphology. Occlusion of the parent arteries, “Hunterian ligation,” is advocated as the preferred method of treatment. The “Alskock Test” is usually performed to evaluate patency of the posterior communicating (PCOM) arteries by compressing the cervical carotid artery during contrast injection of the vertebral artery. A PCOM greater than 1 mm can be visualized and suggests the possibility of collateral flow after occlusion of the vertebrobasilar system. Endovascular occlusion of basilar and vertebral arteries with balloons and coils is used in nonatherosclerotic fusiform aneurysm cases with good results. There are reports of successful treatment of ruptured basilar aneurysms with stent-graft placement from the vertebrobasilar junction to the midbasilar artery.

Thursday, December 20, 2007

Electrophysiology and Multislice CT

According to Saremi F et al in Radiographics. 2007 Nov-Dec;27(6):1539-65,
"Given its capacity to provide relevant anatomic information in exquisite detail, multidetector computed tomography (CT) has the potential to allow faster and more accurate placement of intracardiac ablation catheters and pacemaker leads relative to the anatomy of interest. High-resolution reformatted images from 64-detector CT data provide accurate anatomic information for locating important landmarks relative to the cardiac conduction system or to current electrophysiologic interventions and cardiac resynchronization therapy."

Seems like yet another upcoming application of Cardiac MDCT.

Central neurocytoma









Findings

CT: Ovoid 3.0 cm intraventricular mass arising from the frontal horn of the right lateral ventricle. Arises just above the foramen of Monroe and mildly displaces the septum pellucidum. There is a faint contrast enhancement, and a few small, irregular vascular structures are demonstrated.
MR: Mass is isointense on T1W sequences and mildly T2W hyperintense to gray matter. Internal microcystic change and diffusion restriction is noted. No hydrocephalus.

Differential Diagnosis:
- Intraventricular (central) neurocytoma
- Intraventricular oligodendroglioma (can appear identical)
- Ependymoma
- Others
Meningioma
Astrocytoma
Subependymoma
Germ cell tumors
Colloid cyst
Choroid plexus papilloma


Diagnosis: Central neurocytoma


Discussion

Intraventricular neurocytomas are extra-axial brain tumors seen in young adults and older children with an age range of 17 to 53 years. Patients frequently develop hydrocephalus and symptoms related to elevated intracranial pressure. In addition, patients have also been reported to present with seizures, visual symptoms, or coma. On gross exam, these tumors are near or attach to the septum pellucidum and are well circumscribed. Microscopic evaluation reveals cellular tissue with fine to coarse calcifications being present more than half the time. Central neurocytoma can appear similar to an oligodendroglioma radiographically and histologically, but can be differentiated by a positive immunostain for synaptophysin. Clinically, intraventricular neurocytomas have a good prognosis and generally behave in a benign fashion. Complete resection is the therapy of choice and patients with incomplete resections often still have a good prognosis. Radiation therapy is utilized only in rare malignant cases.


Radiologic overview

CT: Demonstrates a large mass involving the lateral and third ventricles. There is usually associated hydrocephalus. The mass is isodense to brain with fine to course calcification. Moderate enhancement with IV contrast is seen in the noncalcified portions. The tumor frequently abuts or is attached to the septum pellucidum. Extension into the fourth ventricle and extraventricular tissue is associated with anaplastic histologic appearance.

MR: The tumor has a very heterogeneous appearance on MR secondary to its calcifications, which appear hypointense. Noncalcified portions are hyperintense to isointense to gray matter on T2 images. Similarly, T1 images demonstrate the tumor as isointense to hyperintense to gray matter. There is moderate enhancement with gadolinium.

Tuesday, December 18, 2007

Synovial cyst






Findings

Figure 1: An axial T2 image demonstrates a high signal round structure, adjacent to the right facet and postero-lateral to the thecal sac with a low signal rim.
Figure 2 and Figure 3: Axial and sagittal T2-weighted images demonstrate a cystic structure with a low signal rim adjacent to the right facet with mass effect on the right lateral recess at the L4-L5 level.


Diagnosis: Synovial cyst


Synovial cysts are formed by degeneration of the facet joint. Ninety percent of synovial cysts occur in the lumbar spine with 70-80% occurring at L4-L5. The cysts themselves are usually 1-2 cm in size and appear round or lobulated with sharp margins. Synovial cysts are postero-lateral extradural cystic masses and are adjacent to the facet joint. Direct communication with the facet joint confirms the diagnosis but is not always visualized.

Differential diagnosis of synovial cysts include:
- Extruded disk fragments
- Ganglion cysts
- Nerve sheath tumors
- Septic facet arthritis
- Asymmetric ligamentum flavum hypertrophy.

Characteristic imaging findings of synovial cysts include a low T1 signal round lesion adjacent to the postero-lateral aspect of the thecal sac with a rim that is iso-signal on T1 and low signal on T2. Synovial cysts are bright on T2-weighted images and may demonstrate communication with the facet joint. If proteinaceous fluid or hemorrhage is present within the cyst, the signal may be more heterogeneous. The wall of the cyst may enhance with contrast.

Synovial cysts may be incidental findings or may cause varying degrees of central canal, subarticular or lateral recess narrowing. Synovial cysts are usually seen in patients greater than 60 years of age and are more common in females. Clincal presentation may result secondary to chronic low back pain, acute pain from hemorrhage into the cyst or radicular symptoms. Synovial cysts may spontaneously regress with conservative management. Conservative management includes bed rest and analgesia. Additional minimally invasive treatment includes facet injection with steroids and or percutaneous aspiration of the cyst material under CT guidance. Surgical treatment includes laminectomy with cyst excision or hemilaminectomy and flavectomy of the affected side.

Rare Complication of Ultrasound Scanning

SUTTON PA et al in British Journal of Radiology (2007) 80, 1024
doi: 10.1259/bjr/98506488
Report a very interesting complication of a patient who developed acute confusional stae post ultrasound. The investigations sent by them all returned normal, with the exception of a venous sodium measurement of 119 mmol L–1. On further questioning, the patient's husband revealed that she had been told to "drink as much as she could" prior to the ultrasound scan, and had therefore consumed several litres of water over the course of the afternoon. The confusion settled with fluid restriction, and venous sodium normalized over the next few hours.
ooops......

Again highlights the importance of good communication between medical staff and patients.

Monday, December 17, 2007

A Visit to Barasoain Church

After visiting my Lolo's house in Baliuag, I decided to drive to Malolos to visit the historic Barasoain Church. It's been such a long time when I last visited Barasoain. Yet, its still there in all its majesty--possibly the Philippines most historic church. I won't write much today (too tired) so I'll just let the pictures do the talking.


Barasoain Church in Malolos, Bulacan


The monument of Emilio Aguinaldo in front of the church. General Aguinaldo established the Malolos Republic (The First Philippine Republic) in the Barasoain Church in the year 1899.


The original carriage used by General Aguinaldo during his parade on the occasion of the inauguration of the Malolos Republic. The horse died many years ago.


A diorama of General Aguinaldo's parade in Malolos, Bulacan in 1899.


The Madonna and Child inside the Barasoain Convent


A historical marker

And what it read (in Tagalog and English)


The interior of the Barasoain Church.


The History of Three Republics


The beautifully painted ceiling of the Barasoain Church.