## MiWORD of the day is… Mop-top!

Ahhh, the mop-top! I sigh not because I miss the hairdo but because I miss my hair – all of it. In the mid-60s this hair style was made famous by The Beatles. Don’t know who they are (shame on you!) have a listen here for instruction.

Well the mop-top was made popular because the 4 guys who sported the hairdo were crazy successful musicians from England. Their recording company, Electrical Musical Industries (EMI), was also very happy and successful because of the overwhelming record sales (music was sold to listeners on vinyl records back then).

So, what does any of this have to do with medical imaging? Lots actually. The money generated by record sales enabled the EMI basic science researchers (another division of the company) to work in a prosperous cash-rich environment. One of those researchers was Sir Godfrey Hounsfield, an electrical and computer engineer.

In 1967, he started his work on what would soon become the first CT scanner. By directing x-ray beams through the body at 1 degree angles, with a detector rotating in tandem on the other side, he was able to measure the attenuation of x-rays. These values were then analysed using a mathematical algorithm and a computer to yield a 2-D image of the interior of the body. The production of CT scanners by EMI started in the early 1970s and their monopoly ended by 1975 when companies like DISCO (not even kidding) and GE entered the arena.

Interestingly, in the 1960s Dr Allan Cormack of South Africa had also independently showed similar results to Housfield. In the end, Cormack was cited for his math analysis that led to the CT scan and Housfield for its practical development. They shared the Nobel prize in Physics and Medicine in 1979. Cool.

Now for the fun part (see the rules here), using mop-top in a sentence by the end of the day:

Serious: Who would have thought the success of the mop-top Fab Four would be instrumental in the development of the CT scanner?

Less serious: Hey Bob, I went for my head CT scan today and something weird happened. I went in bald and came out with a mop-top! Is that normal?…

Listen to With a Little Help from My Friends from The Beatles to decompress and…

…I’ll see you in the blogosphere.

Pascal Tyrrell

## MiWORD of the day is… Piezoelectric!

Ah, the super villain Livewire. Not sure she was all that much of a challenge for Superman but there you have it: electricity, spandex, and crazy hair. The perfect foe. I wonder if she will make an appearance in the latest Supergirl TV series?

So, today the MiWORD of the day is piezoelectric. Sounds like a fancy name for a downtown pizzaria – but it’s not. Way back before Roentgen discovered x-rays, Pierre and Jacques Curie in 1877 discovered a phenomenon that occurs when crystals are mechanically distorted by external pressure so that an electrical potential develops between the crystal surfaces: the piezoelectric effect. The term was coined by the brothers from the Greek for “pressure-electricity”. So basically, certain crystals (which include quartz, topaz, tourmaline…) can convert electrical to mechanical energy and vice versa.

Why is this important you ask? Well, because this discovery lead to the development of microphones, earphones, and most importantly for us – ultrasound. Based on the physics of sound and not light, ultrasound captures images by manipulating and analyzing sound waves, very high-frequency sound waves as they bounce off surfaces and echo back to the sender. The idea of getting some kind of image from sound waves was first thought of after the sinking of the Titanic in 1912: detecting submerged icebergs with sound reflection.

A little later, in Austria, two brothers Karl and Friedreich Dussik (do you see a trend here?) transmitted sound waves through a patient’s head in 1937. This and then the development of the SONAR (sound navigation and ranging) in WWII was the ground work needed to launch the field of ultrasonography. It would take, however, 20 years after WWII for ultrasonography to become a commercial reality.

Not only is ultrasound one the oldest medical imaging technologies but it is also an important tool for visualizing soft tissue structures in medical diagnosis, follow up of disease processes and pregnancies. Cool.

Now for the fun part (see the rules here), using piezoelectric in a sentence by the end of the day:

Serious: Mom went for her ultrasound today. Told me that I am going to have a little baby sister! She had to wait a while to have her scan because the piezoelectric transducer was on the fritz – again.

Less serious: Hey Bob, do you remember a pizza place on Electric Avenue in Calgary? Piezoelectric something or other? All closed down now. What a shame…

Listen to Electric Avenue from Eddy Grant to decompress and…

…I’ll see you in the blogosphere.

Pascal Tyrrell

## MiWord of the Day Is… UBO?!!!

I must mean UFO or Unidentified Flying Object? You remember the movie Close Encounters of the Thrid Kind? Spielberg’s massive hit in 1977 following his release of the original Jaws. Back in those days UFO sightings were often in the news (or tabloids anyway) and this movie hit the sweet spot. It even helped launch the toy “Simon” which as it turns out was very similar to the multicolored, note-playing alien saucers featured in the movie – coincidence?

So, what the heck is UBO? Well, as it turns out the human body exhibits a variety of anatomical details in the ever so important Magnetic Resonance Imaging (MRI) scan that we have all learned to love (see our series on MRI and Carotid Stenosis). The majority of patients have similar anatomical features on imaging but some fall outside these normative patterns. When radiologists come across findings that are difficult  to interpret they will often refer to them as “Unidentified Bright Objects”. The challenge, of course, is that the radiologist needs to decide whether to label the anatomy in the image an “UBO” – essentially an image artifact – or “disease”.

This is where the rubber meets the road. Interpretation of MRI scans is work done by people, and, as with all jobs, the quality of performance varies. Therefore, the accuracy of the MRI exam is heavily dependent on the quality of the radiologists who interpret them. It is for this reason that the training a radiologist receives is crucial to his/her success. In addition, there is an important relationship that exists between the radiologist and the primary care physician as they have to balance indications of abnormality in MRI scans with the information provided by other techniques such as the clinical exam. A successful diagnosis relies on a good team effort.

Go Team!

Now for the fun part (see the rules here), using UBO in a sentence by the end of the day:

Serious: Went for my MRI today. Told me that the UBO on imaging was just an artifact. Nothing to worry about. Phew!

Less serious: Hey Bob, did you hear on the news the report of another UBO hovering over farmer John’s field last night?  Or was that UFO? I always get those two mixed up…

Listen to UB [4] 0’s Red Red Wine to decompress and…

…I’ll see you in the blogosphere.

Pascal Tyrrell

## MiWord of the Day Is… Magnet!

Who hasn’t thought of having Magneto’s powers? No? Maybe you should watch this Magneto trailer for a refresher.

Ok, now that we all want to be Magneto (secretly at least) what is it that is so appealing with having the power of magnetism? Bill Nye the Science Guy explains it very well in this clip. Have a gander.

In a nutshell, magnetism is a physical phenomena that consists of a field of energy created by “magnets” that attracts or repels other objects. Magnets come in two major flavors: permanent magnets made of materials (such as iron) and electromagnets – the strongest and most widely used in medical imaging.

Interestingly, it is the sum of the magnetic fields of individual electrons that is responsible for all the fun (see quantum mechanics). In the case of electromagnetism the electric current in a wire produces a magnetic field in the same direction of the current. In the case of a permanent magnet it is the magnetic fields of the naturally occurring electrically charged particles of the atoms that make up the material (iron for example) that are responsible. However, for there to exist a force strong enough to attract or repel another object all of its magnetic ions must have their magnetic fields aligned and contributing to the net magnetization. This is how you can magnetize a needle when stroking it in a uniform directional way with a permanent magnet.

Magnetism is to MRI what radiation is to X-rays. The strength of magnets is measured in gauss and Tesla units. There are 10,000 gauss to a Tesla and the earth’s magnetic field is one half of a gauss. Today most clinical MRIs use superconducting magnets whose strength range up to 4 Tesla! Experimental MRIs can run up to 10 Tesla. Now that is more Magneto’s speed.

The powerful magnets allow for better spacial resolution allowing for better sensitivity of the image. However, all this magnetic strength comes at a cost: the production of chemical shift artifacts – ghosts of things that are not really there. This is why we have radiologists to make sense of it all.

OK. Now you are asking what the heck. Magneto in the X-Men movie was able to rip out the iron from a human so why doesn’t an MRI? Great question. Iron found in the human body is mostly found as ferritin (a type of iron oxide) and is NOT magnetic. The iron in hemoglobin is also NOT magnetic. Bummer. So how does Magneto do it? Well either the movie is not scientifically correct (now that would be a shocker) or possibly he could be drawing on magnetite (another iron oxide) that is magnetic and has been found in trace amounts in the blood and brain. It is so little though that it does not cause any concern for MRI. Oh well, so much for Magneto…

Now for the fun part (see the rules here), using magnet in a sentence by the end of the day:

Serious: Hey Bob, did you know that early MRI machines used permanent magnets?

Less serious: Went for my MRI today. Told them I was worried the MRI would rip all the iron out of my blood like in X-Men. They didn’t even know who Magneto was. Whaaaat?!!

OK, listen to Magnetic by Traphik to decompress and I’ll see you in the blogosphere…

Pascal Tyrrell

## MiWord of the Day Is… Xeroradiography!

Who hasn’t done some creative photocopying at some point in their lives? I certainly do NOT condone this type of activity (very naughty) but would you believe me if I were to tell you that for a long while mammography made use of photocopy technology? Yes, I realize this sounds a little funny. Let me explain.

In the 1970s medicine made the association between heavy exposure to radiation for TB and thyroid treatments and the appearance of breast cancer three decades later. A reevaluation of the effects of radiation ensued and a call for ways to minimize exposure to ionizing radiation was made to the industry.

One of the first to answer that call was the radiologist John Wolfe from Detroit Receiving Hospital who in 1966 reported on the advantages of coupling photocopy technology with mammography. Xerox corporation jumped on the idea and developed a commercial unit in 1971 and “xeroradiography” was born! Basically, film from traditional x-ray imaging (yes back then they still used film!) was replaced with a selenium coated aluminum plate that was prepared for the exposure by being electrically charged. The result was that only a short burst of radiation (shorter exposure time means lower dose of radiation) was required to produce a very high quality image.

These xerox mammograms dominated the industry for over 20 years until new technology was developed more recently that provided even finer images with even less radiation. Cool.

Now for the fun part (see the rules here), using Xeroradiography in a sentence by the end of the day:

Serious: Hey Bob, did you know that mammograms produced using xeroradiography were blue?

Less serious: My friend Jane was scheduled for a mammography. Having heard of xeroradiography reading the MiVIP blog she decided to DIY at her office. Problem was the print kept coming out black and white instead of blue from the Xerox machine…

OK, watch the Copy Cat trailer to decompress (or not?!!!) and I’ll see you in the blogosphere…

Pascal Tyrrell

## MiWord of the Day Is… PET scan!

Peanuts. What a great story. The most popular and influential comic strip in history. Snoopy was my first stuffed animal growing up. He still lives with my parents. So what is a PET scan anyway? I don’t recall ever seeing the picture above in any of the Peanuts cartoon strips.

Positron emission tomography (PET) is somewhat of a special medical imaging modality in that it brings together two different technologies from different times. Let me explain. Back in the early 1930s, George Hevesy was a young Hungarian physicist who developed biologically safe and useful radioactive tracers that could be ingested or incorporated into the body in some way.  Physicians would then manually locate where these radioactive tracers had gone in the body by using a Geiger counter at first and then later using special cameras (Kuhl‘s photoscan) to produce a crude emission image.

So, how do we get cool pictures like these ones?  Well we would have to wait another 25 years after the development of radioactive tracers by Hevesy for the start of construction of instruments able to not only detect these radioactive sources in the body but to produce tomographic pictures.

It won’t be until the mid 1970s that PET – as we know it today – would be born. Essentially, a patient receives a emissions scan (PET) and a CT (we talked about that here) or MRI (we talked about that here) scan at the same time. The two scans are then merged together thanks to highly specialized computers (see the pictures in the middle frames). Voila! PET.

PET is both a medical and research tool. Most often used in clinical oncology (medical imaging of tumors and the search for metastases), it is also important in clinical diagnosis of certain diffuse brain diseases such Alzheimer’s disease and other types of dementia.

Relax your brain a little listening to Radioactive by Imagine Dragons and don’t forget the fun part (see the rules here), using PET scan in a sentence by the end of the day:

Serious: Hey Bob, did you know that much of the success of the PET scan is due to the development of the radiopharmaceutical FDG (deoxyglucose) that lead the way to the characterization of Parkinson’s and Huntington’s disease?

Less serious: I can’t believe they developed yet another PET scan. Wasn’t the CAT scan enough?

See you in the blogosphere,

Pascal Tyrrell

## MiWord of the Day Is… Mesopotamia!

You are thinking about pursuing studies in medicine. You have enrolled in all the necessary courses at school to qualify you for the grueling application process and you are actively looking for volunteer opportunities. So why the need to be active in your community?

Today, I want to talk a little about the history of medicine. Around 3000 BC (and no I was not alive then if you are wondering) the middle east was a hotbed for civilizations who were in transition from being mainly nomadic to more settled. This “land between the rivers” – Mesopotamia – was ruled by many successive great kingdoms including the Akkadian, Babylonian, and Assyrian empires. Thanks to many archaeological and written remains we have discovered that healing practices indeed existed and were established during these times.

Mesopotamian medicine was predominantly religious and was delivered by a team of healers: the seers who would diagnose based on divination, the exorcists who would expel demons, and finally the physician priests who actually treated the sick mostly with charms, drugs, and some surgical procedures.  OK, so this intensely codified approach (which meant very little opportunity for discussion)  to healing that dominated the Mesopotamian kingdoms would not be able to adapt or improve much over time and would ultimately not contribute much to the Greek rational medicine that would come a later and evolve into today’s medicine.

So why is it important? For two reasons:

Firstly, by understanding the history of medicine you will better appreciate the importance of your role as a physician in your community – regardless if you are a primary care physician on the front line or a radiologist who works in the back ground. What is important is to feel connected and part of your community.

Secondly, it is interesting to see that though Mesopotamian medicine recognized very early on that factors like cold, alcohol, and unhygienic conditions affected health, they were enable to advance and evolve their medicine as Ancient Greece did through ongoing experimentation and discussion. Moral of the story? Medical research rocks!

Do you remember the Babylon 5 series? It came many, many, many years later! Have a peek to decompress and…

… I’ll see you in the blogosphere.

Pascal Tyrrell

## MiWord of the Day Is… Haptoglobin!

Just got back from the RSNA! Wow what a big conference – 56,000 people this year. McCormick place in Chicago, Illinois (where the conference is held) feels like an airport it is so big.

Love Chicago. Great city.

Of course, I had the pleasure of attending a bunch of great presentations and today I will introduce you to one of them. Tina Binesh Marvasti (say that 7 times fast!) presented on the topic of Haptoglobin. No, not Hobgoblin (not sure who that is? See here) or his infamous green predecessor (see here).

So, what is Haptoglobin you ask? It is a serum protein that binds free hemoglobin – resulting from the breakdown of red blood cells – and functions to prevent loss of iron (contained in the heme group) through the kidneys and to protect tissues from the highly reactive heme groups. Essentially a housekeeping protein that helps to recycle hemoglobin as part of the red blood cell life cycle. Now what if your ability to clean-up free hemoglobin was impaired? Well, quite simply you would be putting at risk those sensitive tissues that come into contact with free hemoglobin.

One important example of this is vessel walls affected by atheroma (AKA plaque). Sometimes these atheroma can bleed (called intraplaque hemorrhage or IPH) which worsens the whole situation. Typically, your body responds by sending the clean-up crew including the Hobgoblin (or haptoglobin, I always get these two confused).

When people have the recessive genotype (Hp 2-2) of the Hp gene they produce less haptoglobin and therefore are at increased risk of damage from free hemoglobin (or more specifically the heme groups).

Tina and friends hypothesized the following:

And she found that having the recessive Hp2-2 genotype was associated with a higher prevalence of IPH in a group of  80 patients (average age of 73 yrs). She also found that the IPH volume of Hp2-2 patients worsened over time.

So what is the take home? The Haptoglobin genotype is associated with IPH which is a biomarker of high risk vascular disease and could identify populations at higher risk of developing cardiovascular events.

Now for the fun part (see the rules here), using Haptoglobin in a sentence by the end of the day:

Serious: Hey Bob, did you know that a recessive haptoglobin genetype may contribute to an increased risk of cerebrovascular disease?

Less serious: My GP suggested that based on my recessive hobgoblin genotype I should consider a healthier lifestyle. Funny, I always figured Doc Ock to be the one to watch for…

OK, watch the Spider-man 2 trailer to decompress and I’ll see you in the blogosphere…

Pascal Tyrrell

## MiWord of the Day Is… CAT scan!

A what scan? I am actually a cat guy myself. Not to say I don’t love dogs but if I had to make a choice…

I just finished reading a fantastic book by David Dosa entitled “Making Rounds With Oscar”. The premise of the book is a story about an extraordinary cat but the subject matter is very serious –  dementia and end-of-life care in the elderly. Have a gander.

So what the heck is a cat scan and what does it have to do with medical imaging?

CT scans – also referred to as computerized axial tomography (CAT) – are special X-ray tests that produce cross-sectional images of the body using X-rays and a computer. CT was developed independently by a British engineer named Sir Godfrey Hounsfield and Dr. Alan Cormack and were jointly awarded the Nobel Prize in 1979. Yes, more Nobel prize winners…

In a nutshell,

– uses data from several X-ray images of structures inside the body and converts them into 3D pictures – especially useful for soft tissues.

– emits a series of narrow beams through the human body, producing more detail than standard single beam X-rays.

– is able to distinguish tissues inside a solid organ. A CT scan is able to illustrate organ tear and organ injury quickly and so is often used for accident victims.

Unfortunately, unlike MRI scans, a CT scan uses X-rays and therefore are a source of ionizing radiation.

Now for the fun part (see the rules here), using CAT Scan in a sentence by the end of the day:

Serious: Hey Bob, did you know that the recorded image of a CAT Scan is called a tomogram?

Less serious: My GP suggested that howling at the moon at night is not normal behavior and he wants to send me for a CAT scan. What? No way, I’m allergic to cats…

OK, listen to Cat Stevens to decompress and I’ll see you in the blogosphere…

Pascal Tyrrell

## MiWord of the day is… Atom!

MiWord, a post on Sunday?!!! Well, I have been very busy lately and fell behind on my blog so I am now playing a little catch-up…

I was waiting in Logan airport for my flight back from a presentation in Boston – what unbelievably crazy traffic in that city – and I was texting my kids with my laptop open and my tablet next to me on the seat when I thought: I feel a little like Jimmy Neutron! I enjoyed watching that show with my kids. Lots of fun. Anyway, that idea of crazy science and the internal structure of the atom as displayed on Jimmy’s t-shirt may be the premise for a great kids show but it also led to the development of MRIWhat?!!! You say.

MRI is an imaging technique. Maybe so, but it is particular in that it does not use any classic photographic equipment (film or lenses) or use x-rays as Roentgen did. It simply numerically measures how hydrogen nuclei absorb and release energy in response to particular frequencies. Need a refresher on the structure of an atom? See this post.

Don’t get it? OK, how about you think of this process as a crazy huge tuning fork. If you were to flick a tuning fork of a certain frequency (pitch) other tuning forks of the same frequency close by will pick up energy from the humming tuning fork and emit a sound in turn. Cool.

The nucleus of an atom can absorb energy and then relax by emitting energy in a similar way. Different atoms (or the same atom in different environments) will have different relaxation rates allowing for the identification of the composition of molecules. Ya, maybe a little complicated.

MRI measures how hydrogen nuclei absorb and release energy. Dependent on the location and the environment of the hydrogen atoms the MRI process is able to provide knowledge about the placement of hydrogen atoms in the body and in turn knowledge about the anatomy.

Now for the fun part (see the rules here), using Atom in a sentence by the end of the day:

Serious: Hey Bob, did you know that the atom is the smallest unit that defines the chemical elements and their isotopes?

Less serious: I thought that splitting atoms would produce a large explosion but when I tried using my mom’s perfume “atomizer” it just produced a fine spray and nice smell…

Ok that was a little intense for a Sunday. Watch and listen to Symphony of Science (very cool BBC production) to decompress and I’ll see you in the blogosphere…

Pascal Tyrrell