PET imaging for Carotid Plaque Evaluation

In Vivo 18 F-Fluorodeoxyglucose Positron Emission Tomography Imaging Provides a Noninvasive Measure of Carotid Plaque Inflammation in Patients

J Am Coll Cardiol, 2006; 48:1818-1824

By Dr. Ahmed Tawakol et al

"Given the importance of inflammation in atherosclerosis, authors sought to determine if atherosclerotic plaque inflammation could be measured noninvasively in humans using positron emission tomography (PET). Seventeen patients with severe carotid stenoses underwent FDG-PET imaging 3 h after FDG administration (13 to 25 mCi), after which carotid plaque FDG uptake was determined as the ratio of plaque to blood activity (target to background ratio, TBR). Less than 1 month after imaging, subjects underwent CEA, after which carotid specimens were processed to identify macrophages (staining with anti-CD68 antibodies). There was a significant correlation between the PET signal from the carotid plaques and the macrophage staining from the corresponding histologic sections. Authors established that FDG-PET imaging can be used to assess the severity of inflammation in carotid plaques in patients."

My Ice Cream!

click to enlarge image

I found this child playing in one of the busy streets of Tondo. I was eating my Ice Cream and he extended out his hand asking for my Ice Cream. I was just happy to give it to him. After I took this picture, he immediately ran away.

Gliomatosis cerebri

Findings

Poorly defined, diffusely increased signal is noted on T2-weighted images (Figure 1) involving predominantly the right frontal and parietal lobes. This abnormal signal involves predominantly the white matter but extends to the adjacent cortex, to the insular cortex and inferiorly involves the thalamus and posterior limb of internal capsule to reach the upper mid brain.

These lesions are iso- to hypo-intense on T1WI (Figure 2). For the size of the lesion, there is not much distortion of the anatomy and there is little mass effect on the ipsilateral lateral ventricle with slight shift of midline to the left.
On the post contrast images (Figures 3, 4 and 5), there are only scattered foci of enhancement in the centrum semiovale and parasagittal gray matter (Figure 3). Foci of enhancement likely represent areas of dedifferentiation.
Figure 6: MR Spectroscopy reveals slight increase in the choline peak and slight reduction of NAA peak.


Diagnosis: Gliomatosis cerebri


Gliomatosis cerebri is an uncommon primary brain tumor characterized by diffuse neoplastic proliferation of astrocytes, with relative preservation of underlying brain architecture and sparing of neurons. By definition, it is infiltrative, involving at least two lobes of the brain, frequently bilateral. Usually WHO Grade III, it is differentiated from multifocal gliomas based on continuity of cellular infiltration and lack of clear distinction from adjacent normal brain tissue.

Patients usually present between the 3rd and 5th decades of life. Clinical findings are nonspecific and characteristically mild in comparison with imaging findings. The process shows a relentless progression over time and typically presents with a slow decline in cognitive function.

The areas infiltrated by neoplastic astrocytes include (in decreasing order of frequency) the cerebral hemispheres, basal ganglia, thalami, corpus callosum, brainstem, spinal cord and cerebellum. The tumor typically crosses the midline and involves at least two, usually three lobes of the brain. Hemispheric white matter involvement is typical, but the cortex may also be involved in approximately 20% of cases.

CT may demonstrate normal findings or may show ill-defined asymmetric low density with minimal or no enhancement. MRI is more sensitive, but also often underestimates the extent of disease. The tumor appears as infiltrating hyperintense mass on T2 WI with enlargement of involved structures. Enhancement may indicate malignant progression or a focus of malignant glioma. Vascular proliferation and necrosis are typically absent.

MRS and dynamic contrast-enhanced T2*-weighted imaging help further characterize the tumor.

Stereotactic biopsy may be guided by an enhancing nodule if present, or by the area of maximum Choline/NAA increase.

The prognosis is generally poor with 50% mortality at one year. Steroid therapy may be helpful in the short term. Radiation therapy and chemotherapy are of questionable benefit.

"Under The Table" Imaging

Found this very interesting article on FilmJacket.com. Read the full article its very accurate.

"What is an under-the-table imaging request? Most radiologists encounter it at some point in their career, be it a foot radiograph for a nurse whose big toe was crushed by a stretcher wheel, a chest radiograph for a coughing ER physician or a gallbladder ultrasound for a healthy-looking resident with right upper quadrant pain. Instead of going through proper channels, the above patients may approach a radiologist or even a radiologic technologist directly and ask for what they think is an appropriate imaging study. There are multiple reasons why such unofficial imaging should be categorically denied and all patients should be directed to seek proper medical attention."

A Night of Music with Robin Gibb

I purchased today a CD of Bee Gees songs, inspired by the recent concert of Robin Gibb in Araneta Coliseum. I truly loved all their songs even while I was young., so it was truly great to see at least one of them in person!

Some fellow bloggers emailed me if I have more photos of the concert. Actually, I was just lucky to bring a camera in Araneta Coliseum. Cameras are not allowed inside the coliseum and even so on huge concerts as this. People who have brought cameras are asked to deposit them in the luggage stockroom of the security guards.

But I'm lucky, the guard on duty did not fully open my bag, so he did not notice that inside, tucked between a shirt and a towel, is my Nikon D80. Well, I don't have any bad intention and I'm not selling my pictures in the internet. I meant to post them only in my blog.

I was seated in one of the upper seats-the cheaper ones- of the Coliseum. I knew it would be difficult to take good exposures because it was dark inside the coliseum. All the lights were of course aimed at Robin. Good thing that my available camera lens was a medium telephoto, an 85mm f1.8 so I was able to take photos of Robin from a dark corner even far away from the stage.

The Araneta Coliseum. Shot prior to my entry for the concert .

The full orchetra prepares for the night of music, while

the crowd excitedly waited for Robin Gibb

Robin Gibb live in Cubao. He was singing here the
famous song "Holiday", one of the crowd favorites.

The big LCD screen is a great benefit for those of us who cannot afford the ringside seats.

The audience are dancing and clapping, to the tune of "Tragedy",

one of the phenomenal hits of the great Bee Gees.

The encore..Robin Gibb delighted his fans with two encores!

The fans reluctantly leave the Coliseum after the last encore.

Everyone was happy and satisfied!

The crowd outside Araneta Coliseum...
We just hope that Robin returns as he promised, and bring along Barry.

Radiology Grand Rounds VI Are Up

Radiology Grand Rounds VI are finally up at one of the Best Radiology Blogs-
Spot Diagnosis

Check it out and enjoy the best in the world of Radiology this month!

Robin Gibb in Cubao!

Robin Gibb of the Bee Gees visited us in Cubao last night and what do you know, he sang for us the many songs for which the Bee Gees became hugely popular all the world over.

Actually I could not afford the ticket, but fortunately my friend Tony Sarreal who works in Araneta Coliseum, gave me a complimentary ticket. Many thanks man, I owe you one!

Although Robin's brother Barry wasn't able to make it to the concert because of tours in other parts of the world, yet it was truly wonderful to see Robin in person, whom I consider one of my most favorite artists.

I am not really very sure about the Bee Gees history, but I think they were originally a five member band that started early in the 1960s. They later narrowed down to three members, brothers Robin, Barry, and Maurice Gibb (who died a few years ago), who popularized the classic songs that everyone loved up to this day, like I Started the Joke, Massachussetts, New York Mining Disaster, To Love Somebody, and countless others.

Indeed, they, more than any other band(with the exception of the Beatles), revolutionized the rock music industry which still influenced a lot of newer rock groups today.

Surprisingly, starting in the late 1970s, the Bee Gees entered the disco music arena with the hugely popular beats Staying Alive, Dance Fever, Tragedy, and countless others, and again, they made significant contributions to the genre. Their influence was far and wide, and in the Philippines, VST and Company was the one they influenced most.

It was a jam packed Araneta Coliseum last night as the crowd was treated to a special night of Bee Gees songs by Robin Gibb. It was great to see that Robin still looked young and lively, and the all-too familiar falsetto nasal voice has not changed, to the delight of the fans. He sang all in all some twenty songs, and that made our night so wonderful!

The crowd excitedly awaiting Robin Gibb

Robin singing my favorite song "First of May".

Wearing a toupe, Robin seemed much younger than his age.

The audience danced to its feet as Robin sang the hugely popular Stayin' Alive

Waving goodbye to his fans, promising that next time, he'd bring along his brother Barry.

The crowd outside the Araneta Coliseum, right after the concert.
The taxi drivers made some nice earnings because of Robin.

Posterior reversible encephalopathy syndrome (PRES)

Excellent case with images here- ARRS Case Of the Day

"PRES presents with nonspecific signs and symptoms including headaches, confusion, visual disturbances, elevated blood pressure and seizures. Clinical findings are not sufficiently specific to establish the diagnosis, however, magnetic resonance imaging (MRI) pattern is often characteristic and represents an essential component of the diagnosis of PRES. PRES is an acute episode of vasogenic edema in the cerebral white matter, with a predilection for the posterior temporal, parietal and occipital regions. The vasogenic edema is likely due to autoregulatory dysfunction and endothelial dysfunction. The explanation for predilection for the posterior circulation is uncertain. Non enhanced CT shows patchy bilateral white matter nonconfluent hypodensity, and contrast enhanced CT images show variable mild patchy punctuate enhancement. The findings in the subcortical white-matter are hyperintense on T2-weighted images, hypointense or isointense on diffusion-weighted images, and hyperintense on apparent diffusion coefficient (ADC) images. PRES has been described with a number of medical conditions including hypertensive encephalopathy, eclampsia, and cytotoxic and immunosuppressive drugs (i.e. cisplatin, cyclosporin, tacrolimus, antiretroviral therapy, and erythropoietin). The reversibility of the clinical and radiologic abnormalities is dependent on prompt control of blood pressure and/or discontinuing the offending drug. If unrecognized, conversion to irreversible cytotoxic edema may occur. Rapidly developing, fluctuating or intermittent hypertension is a particular risk. "

Radiology Job Market

From Auntminnie.com

"Our field faces a multitude of threats: reduced reimbursement, self-referral, radiation safety issues, and a heightened awareness by all payors that we are an important component of healthcare costs. But in the face of our recent growth in demand, our supply is woefully inadequate, leaving us quite vulnerable. While some individuals may appreciate the relative shortage because it results in short-term higher salaries and wages, it may be the proverbial battle success in a lost war. We will have failed as a specialty if we allow a shortage of our own making to lead to our diminution. As it takes at least six years from "match day" to train a radiologist, action must happen soon."

Submissions are requested for the Sixth Radiology Grand Rounds

Dear Readers

Sixth Radiology Grand Rounds is coming up on the last sunday of this month, on 26-11-2006. If you have anything from the world of Radiology send it over fast so that it can be included in this issue.

Send submissions to-

sumerdoc-AT-yahoo-DOT-com

Scheduled host- Spot Diagnosis

Pyriform aperture stenosis

Findings

There is narrowing of the anterior nasal passage (Figure 1 and Figure 2) due to overgrowth of the nasal processes of the maxilla (Figure 1 and Figure 2). The nasal septum appears thinned.


Diagnosis: Pyriform aperture stenosis


Pyriform aperture stenosis is an uncommon cause for nasal obstruction in the newborn period. The patient will typically present with dyspnea or apneic spells during feeding or the inability to pass a nasogastric tube. Clinicians will often suspect choanal atresia as this is a more common cause of these symptoms. The diagnosis is easily made with thin section CT images through the maxillofacial region which will demonstrate narrowing or obliteration of the anterior nasal passage with a normal appearing posterior nasal caliber and choana. A pyriform aperture width of less than 11 millimeters is diagnostic of stenosis.

The differential diagnosis for a child with nasal obstruction should include choanal atresia, choanal stenosis, pyriform aperture stenosis, nasopharyngeal encephalocele, sinonasal polyposis or mucous impaction.

A single frontal megaincisor is sometimes associated with pyriform aperture stenosis and is considered within the spectrum of holoprosencephaly. Therefore, when this finding is noted further imaging of the brain should be performed to rule out holoprosencephaly. The premaxillary portion of the maxilla originates from midline mesodermal tissue. The mesoderm is thought to have an inductive effect on the forebrain, causing this association.

More on CT Radiation concerns

Source and Full article -Medscape

"If a diagnostic procedure increases cancer risk, should patients be informed of that risk? Apparently not, at least for one procedure performed more than 150,000 times a day in the United States. CT scans use multiple x-rays to create three-dimensional images that are diagnostically useful but expose people to far more radiation than conventional x-rays. In fact, one CT scan exposes a patient to the lower range of radiation received by some Nagasaki bombing survivors. Up to one in a thousand patients will develop cancer from this exposure.Sixty million CT scans a year will thus cause cancer in thousands of people. Yet most consent forms are silent about this."

Sample Shots of the Panasonic Lumix DMC-LX1

There are days when I just feel lazy bringing along my beloved Nikon D80 during my walking tour, even though I want to shoot pictures everyday--just the kind of stuff I usually share with you: everyday sceneries, street people, nightscapes, and the like.

A few months ago, I sold my old reliable Sony DSC-T5, a camera which got me started in photography. Now I really regret having sold it, since I can still use that wonderful camera at times when a dslr is just too tiring to carry around, or is not allowed in a certain place-- like a mall, or a museum.

I really long for a digital compact camera that I can easily carry and not be as obtrusive as a big dslr. So, I decided to just purchase one anew. After all, I always thought that buying photographic equipments is a great investment.

Also, I always save some money because I don't have a vice that I must sustain- like smoking or drinking-and if photography is a vice, then it is a vice that can only be very rewarding, and not cause lung cancer and cirhossis of the liver.

After a little research on the internet, I decided to buy a Panasonic DMC-LX1 Lumix. It is a small digital compact, but it is big in features, like it has a Leica lens, an 8 megapixel sensor, and my favorite feature--an optical image stabilizer.

I read a lot of reviews before buying this camera. Generally, the reviews are great. It is an exceptional digital compact that delivers great images. But there has consistently been one bad issue with the DMC-LX1: Image noise when shooting dark or low light scenes.

I've just written in my previous entry that I love night photography. But then, night images can be easily taken cared of by my D80, so no problem with me about the image noise issue of the Lumix.

So, here then are some sample shots of my new digital compact, the Panasonic Lumix DMC-LX1. These photos are all straight out of the camera. No post-processing done except resizing. All are shot handheld using iso80.

You will notice that the photos are set at wide-angles because the Lumix has a unique parameter feature of 16:9, which appears as if you are viewing the photos from a wide cinema screen. Now isn't that cool!

Gen. Roxas St., Cubao

The new Eurotel Hotel(or motel?) in Araneta Cubao

Walkway to the cinema lobby of Gateway Mall where the Pacquiao-Morales III can be watched live. I had an account of the second fight in the January 2006 entry of my blog, where Pacquiao defeated Morales in the final round. This time around, though, Pacquaio simply demolished Morales in the third. I paid the 600 pesos ticket to watch it live. It was worth it.

The cinema lobby of the new Gateway Mall. The domed ceiling remind me of the majestic domed ceiling of the ill-fated Titanic.

My favorite tambayan in the old Ali mall is of course National Bookstore. Syempre..laking National ako eh.

Fruit stand in the Farmers Market where I usually buy my favorite Durian, Lanzones, and Mangosteen fruits.

The new Gateway Mall at dusk. Around 5 o'clock in the afternoon. As you can see, night time is now longer and daytime shorter.

The giant Christmas Tree of Cubao..Ah..I'm very proud and fortunate to be a Cubao citizen!

My personal assesment of the Panasonic Lumix DMC-LX1: I will not say much....I love this camera!

Low Light Test of Nikon D80

I love night photography and I always delight sharing my photos here with you. Almost always, I just photograph those places I frequent or within my radius as an existing human being.

I have a new camera-a Nikon D80- so last night I decided to take it to Cubao to shoot some night sceneries.

Here are some photos I've taken with my favorite Sigma 14mm 2.8 lens. All these photos were shot handheld at iso 800 at the maximum lens aperture of 2.8. All shots were unprocessed except for some minor tweaks in highligthing and cropping.

Dusk at Edsa Cubao. Shot from the Cubao Overpass. I placed my Nikon on the railing of the camera so I was able to make a 2 second exposure.

The colored trees of Cubao

Shopwise Supermarket

Near Romulo St., Cubao

Isetann Cubao

The old Ali Mall, the mall of the great boxing champ Muhammad Ali

The new Gateway Mall

A busy street in Cubao

Jeepney terminal in Farmer's.

My Personal Verdict: Excellent performance of the D80 even in low-light situations. At iso800, the D80 still delivers clean image, even with the noise reduction feature off. I am very pleased with the results and I think that this camera will be my permanent camera....as of now :)

More on Gadolinium adverse effects

"Europeans find more gadolinium-related adverse reactions

Problems with gadolinium-containing contrast agents administered to patients with renal impairment are more common than originally estimated. The lack of awareness among radiologists about the potential dangers for those at high risk is striking, according to researchers. In June 2006, the FDA advised against giving gadolinium-containing contrast agents during MRI exams to patients with renal impairment. The warning came after the Danish Medicines Agency reported that 25 patients with kidney failure developed a life-threatening condition known as nephrogenic systemic fibrosis (NSF, previously known as nephrogenic fibrosing dermopathy). "

Reference- Diagnostic Imaging Online

Progressive Multifocal Leukoencephalopathy (PML)

Findings

MRI shows multiple foci of hypointensity on T1 and hyperintensity on T2 and FLAIR throughout the subcortical white matter of bilateral frontal, temporal and parietal lobes. Similar lesions are seen in left pons and right cerebellar hemisphere. Figure 2 and 3, which are FLAIR images, demonstrate well the involvement of the subcortical U-fibers. There is no significant mass effect associated with these lesions. No appreciable enhancement is seen on postcontrast images (Figure 4, Figure 5, Figure 6, and Figure 7).


Diagnosis: Progressive Multifocal Leukoencephalopathy (PML)


Progressive Multifocal Leukoencephalopathy (PML) is a fulminating opportunistic infection of the brain caused by JC virus. The virus is commonly latent in the central nervous system (up to 80% of adult population is infected) but targets the oligodendrocytes in immune compromised patients. It occurs in AIDS patients with very low (less than 50-100) CD4 counts.

PML typically results in progressive neurologic decline in AIDS patients, but can be the presenting illness.

The need to diagnose and treat PML is urgent in patients with HIV as the infections are synergistic. Brain biopsy was previously required for definitive diagnosis. With positive JCV Polymerase Chain Reaction CSF results and MR findings characteristic of PML, brain biopsy can be avoided in many AIDS patients.

On CT, it presents as focal, bilateral, asymmetric, usually well-demarcated areas of low attenuation, typically in the subcortical and periventricular white matter.

MRI reveals asymmetric, multifocal areas of T1 and T2 prolongation in the periventricular and /or subcortical white matter. Involvement of subcortical U-fibers is common, giving a “scalloped” appearance to the lateral margins of the lesions. Classically, the lesions occur in the parieto-occipital white matter. However, lesions may involve any part of cerebral hemispheres as well as brainstem, cerebellum, and basal ganglia. Mass effect and enhancement are usually absent or mild, if present. Marked mass effect or robust contrast enhancement should suggest alternative diagnoses.

HIV encephalitis is the leading diagnostic possibility in the differential diagnosis of non- enhancing, non-mass-producing white matter lesions in patients with AIDS. White matter changes in HIV encephalitis are usually symmetrical and diffuse. Posterior fossa is also uncommonly involved with HIV encephalitis.

There is no specific therapy for PML, and it was previously considered to be fatal with median survival being around four months. Improved patient survival has been reported with HAART (highly active antiretroviral therapy).

Doctor Google!

"THE practice of "Googling" for a diagnosis could help doctors and patients accurately identify their ailments, research suggests. A study has found that putting symptoms into the Google internet search engine produced the right diagnosis in the majority of cases. But experts warned that relying on the internet could be dangerous to patients and the web should be used with caution. It is thought that doctors carry two million facts in their heads to help them diagnose illnesses, but with medical knowledge expanding rapidly, even this may not be enough. "

From Scotsman News

Cavernous hemangioma

Findings

Figure 1 and Figure 5: T1 axial and coronal images demonstrate the soft tissue mass iso-intense to the adjacent muscles located predominantly in the extraconal plane with minimal intraconal extension.
Figure 2: T1 coronal post contrast with fat saturation demonstrates enhancement of the cavernous hemangioma.
Figure 4: T1 axial postcontrast image demonstrates peripheral hypointense margin from pseudocapsule (arrow at the site of pseudocapsule).
Figure 3: T2 coronal images demonstrating thin septa within the cavernous hemangioma.
Figure 6: Catheter angiogram in arterial phase does not show any feeding arteries.
Figure 7: Catheter angiogram delayed phase shows pooling of the contrast within the cavernous hemangioma.


Diagnosis: Cavernous Hemangioma


Cavernous hemangioma is the most common congenital vascular malformation of the orbit. Female predominance is appreciated with female to male ratio as high as 7:3. Hormonal factors have been implicated as there is more rapid growth during pregnancy. They grow slowly and are composed of multiple endothelial and smooth muscle lined vascular channels. Cavernous hemangiomas are well circumscribed round or oval lesions with well defined margins. They have a pseudo capsule from the surrounding compressed tissue.

The common clinical presentation is painless proptosis. Diplopia, visual impairment, increased intraocular pressure are seen with larger lesions.

Cavernous hemangiomas are more often intraconal. Larger lesions have extraconal extension. Primary extraconal lesions are also reported. Intraosseous hemangiomas are rare.

CT demonstrates the location of the lesion and micro calcifications. Phleboliths and macroscopic calcifications are rare. Remodeling of the bone is seen in long-standing cases. On MRI homogeneous soft tissue mass, which is isointense to the muscle on T1WI and hyperintense on T2WI with well-defined septations, can be seen especially in large lesions. Hypointense pseudo capsule is very visible along the periphery of the lesion.

Heterogeneous patchy enhancement is seen with contrast with more homogeneous enhancement on delayed imaging. Angiography demonstrates no obvious distinct tumor blush during the arterial phase. Contrast puddling is seen, which extends to the late venous phase, essentially isolated from systemic circulation.

Treatment options include observation only for stable lesions and lesions without significant symptoms. Intralesional laser, cryosurgical and radio surgical techniques are other alternatives in addition to surgery. Surgical resection is indicated for visual disturbance, cosmetic reason, and any symptoms related to mass effect. Recurrence rate is very low after surgery.