Monday, December 31, 2012

Cone-beam CT’s, not just for Cone-heads.

Cone Heads was a major hit movie in 1993

Cone-beam CT (CBCT) is making silent inroads into several practices by replacing certain technologies and providing better functionality as well as opening up new applications. The initial application was for dentistry, but it has spread its wings beyond that application. This article explains the basics of CBCT and lists a couple of integration issues you might need to be aware of.

How does it work? Well, as it name already reveals, the system uses a cone or pyramid shaped X-ray beam. As the name implies, it uses a cone shaped X-ray beam that goes through the object to be imaged and hits a digital detector producing an image. Except for differences in beam geometry, it operates very much like a conventional CT scanner. In contrast, the conventional CT has a fan-beam that results in a thin axial slice while the cone beam CT creates a 3-D object.  A CBCT might produce several hundred views while rotating 360 degrees in a single scan which might take 10 to 30 seconds to acquire.

Typical dental conebeam system
Compared with conventional radiography, such as a panoramic X-ray, the resulting images have less distortion, and compared with a conventional CT scan, they have a much higher spatial resolution, i.e. less than .01 mm, which allows for much higher precision that is especially important when creating dental implants. This higher resolution is mainly due to the smaller Field of View (FOV), ranging from 5 cm to 15 cm. The contrast resolution however, is much worse than for a conventional CT, due to several factors but mostly because of the high impact of the scatter radiation. The scatter radiation is typically characterized by the scatter to primary radiation ratio, which is typically .15 for a conventional CT scanner, but can be as high as 2.09 for a CBCT scanner.

The dose for a CBCT scan could be 5 to 100 times higher than for a conventional panoramic X-ray, but is at least 5 to 100 times lower than a conventional CT scan. This wide range is due to a wide range of dose delivery based on the field of view, collimation, and design differences among manufacturers. The cost is also definitely higher than for a conventional X-ray unit, as these devices cost at least $100,000, which might be a little bit hard to justify for a regular dental practice, which in many cases is barely able to afford a digital system to replace conventional byte wings.

O-Arm: cone beam CT for spine imaging
However, many years ago people would not have imagined that CT would now be the standard of care. In many ER’s, trauma patients are by default getting a CT scan, especially when there is any suspicion of head trauma. This is despite its higher cost and much higher dose delivery compared with a conventional X-ray. The same could happen with dentistry, where the panoramic X-ray units might start to be replaced with these CBCT systems, which is a scary thought. The scary part is that dentists are not really trained (yet) to interpret these types of images and do not have experience with radiation safety measures for their patients and staff. This is especially true if these systems are installed in a non-dedicated room, but, rather in a hall way or closet.
Dentistry is not the only application for CBCT systems, the high precision and portability also allows for ENT specialists to better image the inner-ear with its intricate structures. There is a also a dedicated CBCT system which allows for spine imaging, especially for spine surgery applications, which is referred to commonly as a “O-arm,” in comparison with the popular C-arms. There is a CBCT developed for extremity imaging as well. The latter allows one to stand up and therefore to image joints while carrying its person’s weight.
Extremity Imaging

With regard to integration, all these systems have a DICOM output for storing the images in a PACS or enterprise imaging and information system, and a worklist allowing these procedures to be scheduled in an information system or CPOE (Computerized Physician Order Entry) system. Scheduling might be a little bit tricky as the scheduled procedures have to be mapped by the modality worklist provider or broker to a specific station AE title. The dose reporting for these systems also is lacking as most CT scanners are starting to create the so-called DICOM structured reports to register this information because there are still changes that have to be incorporated in the DICOM standard to facilitate this specific geometry for dose reporting.

In conclusion, there are a few challenges with regard to implementing and integrating these systems, and the standard still needs to catch up with regard to dose reporting, but there is no question that these devices are here to stay and will increasingly be implemented in your enterprise systems. Therefore, it is time for support professionals to get ready and learn as much as they can about this new technology and be prepared to implement them. I myself learned a lot about this technology from my fellow DICOM expert Dr. Allan Farman who co-authored an excellent tutorial about this technology (see link).

Thursday, December 13, 2012

The bottom ten things you did NOT miss at RSNA 2012.

If you missed RSNA this year, you definitely lucked out; see my write-up here (earlier blog) about my top ten items. However, there are also several things you might not be sorry that you missed, so, here is my bottom ten list.

Adding these to Meaningful Use?
1.       Ultimate recliners – I am not sure what RSNA is doing about the decline in attendance (it was close to 10 percent lower this year), but I suspect that they are testing the waters and strategically posting some booths that are totally unrelated to radiology such as recliners. It does fit within this year’s mantra, which is all about the patient, so in addition to having the latest and greatest 640-slice CT or PET/MR, a patient might be pulled into the imaging center by recliners in the waiting room. Who knows, maybe next year the Lakeside hall might be dedicated to office and waiting room furniture. I actually wouldn’t mind having more of these as this particular booth was always packed and I would never have a chance to relax myself.

Ernie and his partner
      2.       Ernie’s welding shop – I found Ernie and his partner in the back of the hall promoting their welding shop while showing off some great work. I bet he has his Harley Davidson parked just behind the booth, and I am sure he would be able to create a custom job for your bike as well. I was unaware of the need for custom welding in the healthcare imaging field, but I guess as increasingly the production of tables and other mechanical parts is shifted to China, there could be an increased need to repair those, hence the need for Ernie.

Let me dry-skin you
3.       The ultimate dry-skin remedy– If you are on a limited expense budget or per diem that does not take into account the ridiculous price of food in Chicago, you most likely found yourself standing in the icy wind waiting for the morning and evening hotel shuttle buses instead of using a taxi. This is definitely detrimental to your skin, especially if you are from the south. The solution was offered by friendly ladies who tried to get you to use their all-natural Hawaiian Aloe skin lotion. Go for the daily free samples that will save you the expense of having to buy a pot of their cream for the RSNA “special” price of only $40, cash or credit card.

Great view from the walkway
      4.       The indoor walk trail/circuit ­– Where else would you find a tradeshow that purposely divides the meeting rooms and vendor booths on two sides of a major highway requiring you to walk about half a mile every time you have to go from one to the other side. This is especially dangerous during the times that courses are starting. You might bump into a person from Great Britain or Japan who is still severely jet-lagged and walking on the left side of the corridor. Or even worse, you run into someone who is in a heated phone discussion or is texting while walking. I strongly recommend that the RSNA put signs or arrows next year to indicate where people are supposed to walk and to prohibit texting while walking.

No recliners, but it will do.
5.       The most comfortable couches – So you finally got a sandwich costing you and arm and a leg, and then you find out there is no place to sit. I have seen many of those semi-desperate people as they try to hold on to the coffee, sandwich and an RSNA shoulder bag, wandering around looking for a decent seat. Here is the secret. In the middle of aisle not too far from the entrance, there are several comfy seats just waiting for you to plop down. But wait… maybe this is not part of the RSNA, well, at least they get the prize for the most minimalistic, yet functional booth.

      6.       The Jaws-sequel – One thing you probably won’t miss is the party hopping between vendor receptions in the evenings. One suggestion for next year is that we have a hangout, meetup, or whatever the latest social media term is, to let people know where the best food, entertainment, and/or drinks are so we won’t waste time attending receptions that are poorly attended and/or cheaply catered. (My favorites are those that serve Belgian chocolate and Swiss cheese). After these busy evenings, I typically try to unwind a little in my hotel room while watching some old rerun on HBO, in this case the movie “Jaws.” So, when I turned around the corner of an aisle the next morning, while semi-sleep- walking, I saw this big gaping jaw, which caused a flashback to the jaws movie. It was actually the so-called O-Arm, a cone beam CT dedicated to visualizing the spine, but that is besides the point.

Hustling the streets
7.       The cab drivers – The bus transportation system works great, but sometimes, when carrying a lot of luggage, I am compelled to take a taxi instead, or if I just missed the bus and don’t want to wait another 20 minutes in the freezing cold. I think Chicago taxi drivers rate as the worst among metropolitan cities. You are lucky if the driver will put your bag into his trunk, the curbside is definitely off-limits for them. The credit card machines in the back work 50 percent of the time, and if they do, they are cumbersome and seem to operate randomly. One time the driver actually shouted at me that I must be stupid to not know how to use it. They never wear seat belts (isn’t that the law in Illinois?) A good reason for me to wear mine is that the drivers strictly comply with their minimum speed limit on the highway of 80 mph. Their accents have to be worse than my “Texan accent,” so they are hard to communicate with. And yes, they also have to speak constantly on the phone using their Bluetooth earpiece in some language that is either Russian or an Arabic dialect.

Where to eat?
      8.       Lunch at the Hyatt – You would think that the Hyatt, after so many years of RSNA, would have learned a bit from how we manage wait times and communicate that effectively to potential clients. For example, in the metroplex where I live, there are signs along the highway notifying you of the wait time for the next ER down the road. One of them was actually quite innovative, as it advertised that you’d be seen in 15 minutes or it would be free! Going back to the Hyatt, I actually gave up trying to have lunch there, as the last time I checked, the waiting time was one hour for the next table. RSNA is very much about networking and talking with potential clients, partners or other associates over lunch or breakfast. I suggest therefore that RSNA consider signs in each of the corridors listing the average wait times to have lunch (and coffee!) at the various locations.

Ice-skating below
9.       The jelly bean – If you missed the Chicago jelly bean, shame on you. That means that you have spent all your time in your hotel room, going to early morning lunch meetings at yet another hotel or the Hyatt, ran to meet someone for coffee just before the exhibitions opened, spent all day running back and forth between halls A, B and Lakeside while also trying to catch a few interesting presentations, jumped in a cab at night to go party hopping to network and then went back to bed after watching some old reruns on your TV. Chicago in November is at its prettiest, just before the icy wind and snow starts. Next time, make sure you take at least a few hours off to explore this great city.

Worth the wait?
      10.   The lines for Starbucks – I need my coffee fix in the morning and also preferably in the afternoon. However, it appears that they can’t bring in enough baristas to get the wait time to be somewhat reasonable. I think I only had coffee once, and that was because someone else had ordered me an extra cup. It would be great if we could text our orders in, prepay with paypal from our smart phone and simply pick up our order. Who knows, maybe I’ll live long enough to see this happen.

All kidding aside, this was my 29th year visiting RSNA, and I wouldn’t miss it for the world. I can deal with the cold and grumpy cab drivers because of the opportunity for meeting old and new acquaintances, and I kind of enjoy the “off-the-wall” booths. However, having a place that you can order a coffee in less than 5 minutes, and actually have a seat to enjoy it and talk with someone would be nice. Maybe next year’s mantra should not be “all about the patient” but “all about the customer.”

Thursday, December 6, 2012

IHE certification: overstepping its boundaries?

IHE USA and ICSA labs have announced a new certification program which, according to a recent press release, will start at the Jan 28 connectathon.

Monitors at work at the connectathon
There is no question that the IHE organization had a major impact on interoperability because of its definition of many profiles in multiple domains, and the development of tools, test transactions, images, and educational programs and seminars. This activity, especially the connectathons, have been a major benefit to the industry as a whole and ultimately resulted in more effective and efficient care. Its work has had a major support from the user community and the industry. 

However, the recent press release indicates a major departure and extension from its current activities.

As a reference, the IHE governance states the following activities:
1. Development activities: the work that leads to publication of the IHE Technical
Frameworks; international in scope; organized along clinical and operational domains. 
Typically within each Domain, a Planning Committee annually selects the use cases and a Technical Committee profiles the use of standards to address the use case, documenting them in Technical Framework documents and their supplements.  A Domain Coordination Committee ensures that consistent processes and technical directions are followed. 
2. Deployment activities: regional/national testing and demonstrations of the profiles contained in the Technical Frameworks and their supplements, as well as promotional and educational efforts. Testing activities include the development of testing software and related tools. Deployment activities are organized by National and Regional Deployment Committees that are separate entities with a close collaborative relationship with IHE International.

In my interpretation, certification is not currently defined in the governance and I would expect that this would require a change in the governance, and discussed with all stakeholders prior to taken this major change in direction. I am not a direct stakeholder, so I don’t know whether that has happened, but if so, I can’t understand how they would have agreed to this, especially because ICSA labs is a commercial entity (a division of Verizon).

Am I over-reacting, interpreting this incorrect or confused? Reactions are welcome.