Online Classes

In the world of the internet, more and more teaching institutions are going to either hybrid or fully online courses. I've been teaching online courses for a few years now, and here are some helpful tips for students of any kind for online success:

1) Log onto your online course every day. Doing this at least once a day will promote good communication of due dates, announcements, grades, or any changes in the lesson plans.

2) Check your email every day. Sometimes, when instructors have information for one or two students that does not apply to the entire class, the more private way of communicating these issues is through email.

3) Check due dates... and write them down somewhere on a calendar or daily planner to give you a place to look when your computer is not on. I know from personal experience that toward the end of a lengthy online course, the last thing I want to do is log onto my computer to check these. It's less effort to simply look at a calendar on the wall to know what you have to turn in for the day, and you can see what's coming for tomorrow.

4) Work ahead, if possible. The flexibility that online courses offer can be a pro or a con. Students who do not take advantage of the "work when you can" attribute to online courses can sometimes find it easy to procrastinate instead, thinking "I have until midnight to take this test... I'll start it at 11:00." Most courses will allow you to do your final lesson/exam at least a week before the end date of the course... if you have a course to follow, this could give you a week off to rest your noodle.

5) Ask questions. Simple, yes, but also realize that most online courses allow instructors a 24-48 hour response time for any questions. The #4 tip will help you with this... if you have a test due Friday, don't wait until Thursday to ask a question when you've had all week to look over the material. You will find yourself in a state of panic when it could have been avoided.

6) Communicate well... be specific when asking questions in an email. Make references to which book, page number, question number, on which chapter number, test number, assignment number, etc. that you are referring to. I commonly receive questions like "what was the answer to #3?" With a 48 hour response time, a lot of time can be wasted, and your answer may not be addressed, before the week's lesson is over.

7) Sign your email. Depending on how your online course is set up, the instructor might only receive your email address in the "sent from" box, and if you don't sign it, there's no way of knowing who the email is from. Make sure to sign your first and last name with each email. If you don't, all the instructor knows is that the email is from "awesomeradtech@yahoo.com." The other alternative is to create a free email account using your name as part of it.

8) Make sure you have the correct textbooks. Find out which editions you can use, and that you are purchasing the correct ones. Websites like Amazon.com will have some great deals that can save you money rather than buying new textbooks, but the extra effort must be made to purchase the correct editions, or any accompanying materials that the course requires like cd's, flashcards, or lab workbooks.

9) Browse the course well before any due dates. Make sure you are comfortable with the platform you are using... especially if you're not a "computer person." This will dramatically improve efficiency if/when you're in a time crunch and need information quickly.

10) Last, but definitely not least, take an online course before committing to any completely online program. If you are not sure that you are the type of student that is self-motivated enough to perform your assignments and diligently work without supervision, test it out. Take a prerequisite course at your local community college to see if you are the type of learner that is capable of doing an online course outside of the classroom. Some people just learn better inside a classroom and need that instructor/student face-to-face interaction... important to consider before committing to a 2 or 4 year dedicated online program.

What is CQ2011?

Well, it is what someone who is probably a high school junior today will have to deal with if/when they decide to go to x-ray school after high school, and then attempt to renew their registry.

The new "Continued Qualification Requirement" is stated to take place for examinees taking the ARRT on or after January 1, 2011. Instead of requiring a 24 CEU biennium renewal, future examinees will be required to show some form of continued qualifications every ten years in order to renew their registration. What that exactly entails, we do not know yet, but the ARRT promises us that specifications will be available around April, 2009.

There is no current plan to begin this new requirement for individuals who have obtained their registry before January 1, 2011, and the traditional CEU biennium will continue to be observed. It is important to note that all new certifications acquired after this date will be subject to the new requirements and issued a time-limited certification.

A more detailed explanation, and a FAQ section can be found on the ARRT's website here.

The name is Gorithm... Al Gorithm

If you haven't been introduced to Mr. Al Gorithm (algorithm) yet, I can assure you he's not sipping a vodka martini - shaken, not stirred. No, an algorithm is what you are selecting on CR/DR systems in the pre-processing moment when you pick the body part and position that you are about to perform.

The algorithm is a pre-programmed set of mathematical codes used by your imaging software that is responsible for the image appearance after processing. It basically gives you a "model" histogram that the image should look like, and matches the actual histogram produced by the image to the pre-programmed one. The algorithm controls the brightness and contrast (gradient processing), edge enhancement and smoothing (frequency processing), and even histogram equalization. Appendix for Digital Acquisition and Display: ASRT. Brittain, Burns, Nethery, Smith.

Here is a clinical situation you may be familiar with: You go to shoot a cross-table cervical spine for a patient who is in a collar and lying on a backboard. You use plenty of technique that SHOULD provide you with adequate density and an appropriate scale of contrast, and you might even get an optimal S-number of Exposure Index, but you have trouble seeing the C7-T1 space. If you've been around a seasoned technologist, or if you really understand computers, you may learn that changing the algorithm in post-processing may actually allow you to visualize that space without any additional exposure to the patient. You know that choosing "axillary shoulder" or "cross-table hip" will allow visualization of the part, so you go right ahead and do so, patting yourself on the back because you've upheld the standards of ALARA and you've managed to even save time getting the patient off of the backboard without having to repeat.

While those goals are excellent, and I commend you for striving to achieve them, here's the problem: This is a short-term solution to a long-term problem. Let's say one year down the road, the films that you took are requested with a subpoena as evidence in court. The patient may have been involved in an MVA and possibly had some long-term neck injury complications and could be suing... yadda yadda yadda. They call upon a specialist in the field (probably a Radiologist) to interpret your films in court that look so pretty, but say "cross-table hip" on the exam type. The defense lawyer questions whether or not the Radiologic Technologist who performed the exam really took Anatomy and Physiology, because obviously, the x-ray (as supported by the Radiologist on the stand) is in fact, of a cervical spine - not a hip. The films are thrown out as evidence as an insubmissible legal document because of errors.

Mr. Gorithm has seemingly bitten you in the rear while masquerading as your friend all this time. The real question here is how can we avoid this unpleasant circumstance? In order to answer that, we need to know who programs your algorithms for your CR/DR equipment. Usually, when this equipment is purchased and installed, a representative from the manufacturer provides the initial calibration and setup of equipment. It might be a good idea to write into a sales contract for this person to come back at a future date to update and/or make any additional changes that may have been unforeseen at the initial time of setup. Some larger hospitals may have someone on staff who could, in this situation, create a new algorithm for "x-table c-spine" that resembles the histogram of a "x-table hip." Just be aware of your service contract and its limitations to any non-manufacturer personnel making these changes... you don't want to void your warranty or any part of your contract.

Ideally, each projection or exam type should have its own working/calibrated algorithm to process it under. It may cost your facility a little bit of money to initially set this up, but how much will it cost the facility (or your patients) in the long run?

What do you use?

I've only been on the east coast now for about two years, but I have noticed (at least in the facilities I've visited) that there is a huge difference in the type of Imaging Systems being used in the clinical setting.

I've taken x-rays now in three different states, and each of them have varied in the type of equipment used. Also, I have found examples of facilities in each state that have used more than one type of imaging system as well.

What I would like to do is obtain a general survey of what you are using at your hospital, imaging center, or urgent care center. I am posting a poll in the right hand column of this blog. If you could check off what type of combinations you are using, as well as post a comment to this entry stating what state you live in, I think it might give us all some perspective about how technology moves through the country, and who may be utilizing it the most.

Just for fun, check out the latest DR system from GE.

It's not a memo... it's a mission statement.

After reading the details of an interesting study on Faculty Development Needs performed by the ASRT, I found myself distracted from my original interest in the results by the demographic data that I was reading to conclude that I am convinced that we will be in great need for educators in the United States for Radiography Programs in the near future.

Some interesting results for demographics of Full-time Faculty for Radiography Programs, as reported were the following:

Over 2/3 female
Approximately 92% caucasian
Average year for (R) certification was 1983
Average year born was 1960 (or avg. age 47)
Average # of years in education = 4

When asked when they were planning on leaving the education profession, about 1/5 of full-time faculty (and 1/4 of program directors) stated they would be leaving within the next 5 years, and half of faculty/program directors would be leaving within the next 10 years.

It is obvious from the collected data quoted above that the majority community of Radiography Educators is approaching retirement age within the next decade. Having been very recently affected by instructor retirement at my own institution, it is resoundingly clear that with all of the accumulated years of experience that these instructors have acquired, we all have some distinguished shoes to fill.

So why am I talking about this on a blog mainly visited by students? Well, over the next 5 years, those of you who will be graduating from Radiography Programs across the country will be the prime position to jump aboard the pendulum downswing of the educational market demand. Now is the time to be thinking about your next step; what you want to do after you successfully acquire your ARRT Registration, and have a few years of technologist experience under your belts. If you have any interest in education, it might be beneficial for you to research the possibility of steering your careers toward education for the upcoming time of need.

It doesn't take long in this field to notice the symbiotic relationship between educators and technologists. What I have yet to experience (at my ripe young age of 30) is how educational standards will be maintained when such a large percentage of upcoming retirees with their vast levels of experience both in Radiography and Education will be passing the torch. Now is the time for us youngsters and newbies in the field to step it up; to display our enthusiasm for our field, to learn as much as we can from these great contributors to our profession, and to move forward in a fashion that honors those before us.

Contrast in Review

It's always a good idea to review topics like contrast that have so many of those arrows going this way and that. It reminds me of one of those street signs in Europe that you see on the movies where 10 roads come together at one intersection, and you can't find your destination because the signs are written in a foreign language. Hopefully, the concept of contrast does not remain a foreign language to you. Still, we can look at how changes in exposure factors effect contrast:

Changes in mA, time, or overall mAs should not affect contrast at all. It is important to remember that you must have adequate density (optimal or acceptable) in order to properly evaluate contrast. So it can be said that if you have excessive density - too dark, or insufficient density - too light, then you would experience a decrease in contrast.

We know that kVp is inversely related to contrast, and is our primary controlling factor of contrast. As we increase kVp, our contrast decreases.

Filtration is used to increase the average energy of our beam, or "harden" the beam. As we add filtration, the average kVp of photons getting through is higher, so the contrast will decrease. It's similar to increasing your kVp slightly without any other changes.

Field size has a dramatic effect on contrast. If we use the entire field size on a 14x17 cassette on a lateral l-spine, we would be irradiating much more tissue than we need to, causing tons of scatter and lowering contrast. So when we decrease field size (collimate), we are avoiding unnecessary tissue irradiation, thereby reducing the amount of scatter produced, which reduces fog reaching the film, and improving contrast - all while withholding the standards of ALARA - give yourself a pat on the back.

When we have increased motion on our films - the ability to distinguish a very light area from an adjacent dark area on the film becomes blurred. When there is less of an ability to "distinguish shades of gray from one another" contrast has decreased, even though technical factors have not changed.

Patient size affects contrast quite a bit as well. If I take a KUB on a 20cm abdomen and have optimal contrast, then I go to take a KUB on my next patient with a 35cm abdomen, I am increasing the thickness of tissue, which will absorb more of my photon energy, reducing image contrast.

Now we have our grid ratio - thank goodness for grids. As I increase in grid ratio, the quantity of scatter-absorbing lead increases, as well as the hight of the lead strips. As the lead strips become taller, their propensity to allow even slightly scattered photons to pass through decreases. So an increase in grid ratio means an increase in image contrast.

Focal spot size has no effect on contrast... one less thing to worry about.

SID - well, two less things to worry about - no effect on contrast.

OID has some effect on contrast (air gap technique). As you increase OID, the percentage of scattered photons reaching the film decreases due to their angle of scatter. If a photon is only slightly scattered, you can eventually increase OID enough so that the scattered photon will miss the film. This reduces scatter reaching the film, therefore increases contrast.

Developer time/temperature will affect contrast as well. This goes back to what we discussed with having the appropriate density before we can properly evaluate image contrast. If the developer temp or time are too short, then your image will be too light, therefore have decreased contrast. If the developer temp/time are too high, your image will be excessively dark, therefore image contrast is still decreased.

Last but not least, we have film/screen speed. I waited until last because there seems to be some discrepancies between textbooks on this one. One textbook says that there is no effect, while another textbook says that an increase in screen speed produces an increase in image contrast. It goes on to mention that the increase in contrast is probably not enough to visibly see, or to make much of a difference in your optimal image, but it does occur. I would actually like to see what everyone can find from their own sources and post in the comment section here. I've only looked at three books myself, but I'm all for having as much support as possible.

Looking for tips on success through Radiography school?  Check out my book HERE.

Filtration

What is a filter? Well, if you're a coffee drinker, you are familiar with filters. A nice brew is created by placing a filter in the coffee maker and filling the filter with ground coffee beans, allowing the desired coffee (created when hot water soaks the grounds) to flow through to the pot, while preventing the unwanted portion (the grounds) from trickling down. This is not so different from radiographic filters at all.

An x-ray filter is composed of Aluminum equivalent material (Al - not to be confused with Pb for shielding) and is between the target and the patient for the purpose of preventing unwanted photons (the grounds) from passing through while allowing the desired photons (the coffee) to pass through toward the patient.

So which photons do we want to keep and which ones do we want to get rid of? Our duty as Radiologic Technologists is to keep radiation exposure levels of the patient at a minimum (ALARA standards). So, in any x-ray exposure, there is a portion of the beam that will be at a very low energy for the part being x-rayed. It is so low, that it does not even contribute to the useful beam, and it ends up getting absorbed in the patient contributing to radiation dose - BAD photon!

A filter allows us to remove a majority of the bad photons while allowing the good photons (higher energy) to get through to the film. The line of thinking goes something like this: "If the low energy photons are not going to contribute to our image anyways, why not remove them?" Take a look at the picture of an unfiltered beam:



Here I have randomly selected five photons with varying energy levels (we all know that just because we select 70 kV, it doesn't mean all photons produced are at their peak). To calculate the average energy of the beam using these photons, you add them all together and divide by 5, which gives you an average energy of 50 keV. The 30 and 40 keV photons are probably going to be absorbed by the body to contribute to radiation dose to the patient. Now, lets look what happens when we add filtration:



Notice, the two lower energy photons are removed, and the remaining photons have a higher average energy of 60 keV. This is also referred to as "hardening" the beam. Note that any time you add filtration without changing any other factors, you are reducing the intensity of your beam, so an increase in technique is always required when adding any absorbent material. The resulting energies are shown in the following graphic representation of exposures made at 120 kVp:



HVL - half value layer is any amount of material (or in this instance, filtration) that reduces the intensity of your beam to half its original value. Consequently the TVL (tenth value layer) is the amount of material that reduces the intensity to one tenth the original value, and so on.

Types of filtration:

Inherent filtration is any filter that is present as part of the radiographic equipment, and usually includes the glass envelope surrounding the tube, as well as any oil around it. This usually makes up about .5 - 1.0 mm Al equivalency.

Added filtration is just as it is described - anything added to what filtration already exists within your equipment. It usually resides between the tube housing and the collimator box. See the following picture from "Principles of Radiographic Imaging" Carlton/Adler 4th edition:



Total filtration = inherent filtration + added filtration. According to the National Council on Radiation Protection (NCRP), total filtration must be a minimum amount depending on the kVp range you are using:

Below 50 kV - 0.5mm Al
50 to 70 kV - 1.5mm Al
Above 70 kV - 2.5mm Al

Compensating filters are for another post... to be continued...