CBCT Scanners: Understanding Low-Contrast Detectability?

Anon. asks:

I recently had a debate with a company that will only endorse the i-CAT CBVT scanner. Their rep told me that all other scanners including the one I have is not good enough to produce accurate surgical guides. I’d like to get some feedback from others on this issue.

This is exactly what he wrote to me:
“Almost all CBCT scanners (including the i-CAT) offer a range of voxel sizes (from 0.125mm to 0.4mm in the case of the i-CAT) but we find that low-contrast detectability is more important when planning implants as it makes it easier to see low-contrast structures such as the ID nerve and also makes the bone crest stand out better from the surrounding tissue. The low-contrast detectability is largely due to the detector system which in the case of the i-CAT is an amorphous silicon flat panel with 14-bit resolution.”

Basically, he says that no other CBCT scanner has the low contrast silica detector system of the i-CAT system. Does this mean the only the I-CAT can visualise the IDN and crestal bone? Wondering if someone could shed light on these comments for me. I actually have an E-WOO Technology Picasso CBCT scanner with 0.2mm slice resolution, and my images are clearer and have higher resolution. So I’m wondering what’s going here?

31 Comments on CBCT Scanners: Understanding Low-Contrast Detectability?

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Marcel Noujeim
4/1/2008
I have three different cbct machines (morita, planmeca and alphard) and we read images from all over the US taken on all kind of CBCT machines, I work a lot with 3D prototyping and 3d models. I didn't find any superiroty with the i-cat images, they are like any other average machine ( inferior in fact to two or three of them but I don't want to mention names) I think what the guy is telling you is pure marketing.
Brad Bynum
4/1/2008
Is anyone using Planmeca Cone Beam with Nobel Guide. I understand Plan Meca has increased the size of their scan? I was told Nobel Guide did not work with Planmeca.
gary henkel
4/1/2008
much as i love imaging sciences, i use it and do consulting for them, what you were told is a lie, which a quick simple look at your e woo images should attest. all systems must be dicom compliant. and finding the ian is about as obvious on an image as there is. the illuma unit uses a similar sensor to the icat. there is a lot of nonsense that flies around about cone beam. there are now about 15 units on the market, and although i think the icat is one of the best, there are others that record excellent images. gary
Scott Keith
4/2/2008
The Iluma CBCT, made by Imtec and distributed by Kodak, uses the same amorphous silicon flat panel sensor technology as the i-CAT.
AVIK
4/2/2008
thanks for the support guys I thought this was the case and I found out that my CBCT machine uses a 16bit amorphos silica flat panel - which is higher resolution
John DiPonziano
4/2/2008
I am in the market for a CBCT for our office for implant surgical planning. We are going to set it up to be able to scan for other offices as well. Primarily though, I am interested in the best images for my implant planning. I understand some machines that have a broader image size are better able to produce a lateral ceph type image which would be more comfortable (familiar) for orthodontists to read. I am debating whether to get the Sirona Galileos or I-CAT. Can someone shed light on these issues? Thanks, John
Dr AJD
4/2/2008
John for your info Neither of the machines mentioned will do a lateral ceph image - you will end up taking a CT scan to gain a lateral ceph type image which is rather a high dose - there is a machine that is a OPG/lateral ceph and CBCT scanner - its the one I own and its called the e-woo picasso have a look at the machine - the lateral ceph arm is an extention that will take a low dose lateral ceph image without having to dose your patients with a CT scan. Really in all honesty Ct`s are great but for orthodontic diagnosis - where a lateral ceph will do the dose is not justified - you must consider risk Vs benefit to your patients when prescribing such information
Arun Singh
4/2/2008
One thing to keep in mind is that a company that provides implant planning/surgical guides would have no benefit in excluding data from any unit, in fact their business model depends on receiving cases from a broad customer base. The only logical reason for stating a preference would be the quality of the data, hence the effort involved in processing it, as well as the success rate. Therefore I don't see any basis for Dr. Noujeim's assertion that this is "pure marketing". Please also be aware of the fact that a few systems deliver 4 to 10 times higher radiation dose to the patient compared to the iCAT, perhaps gaining some aesthetic or perceived advantage, but the iCAT has been designed to maximize the diagnostic content at the lowest possible dose, and most third party systems (providing Implant/ortho planning & visualization) agree. A few other comments warrant clarification. The so called "16-bit amorphous silicon flat panel" is exactly the same panel as the 14-bit one, the extra 2 bits can be extracted in the future via a special hardware feature to be supplied by the manufacturer. On the question of a "low dose lateral ceph", 2-D cephalometry is expected to become obsolete in the future, due to its inherent limitations, while 3-D cephalometry is fast becoming the standard choice. The iCAT provides the largest Field of View (FOV) for ceph coverage (23cm diameter x 17cm height, cylindrical), while Sirona's spherical FOV with 15cm diameter provides sufficient height only for children and very small adults.
Marcel Noujeim
4/4/2008
Hi Again Thank you Mr Singh for paying attention to my reply ( it is wired that you ddidn't say anything to Mr. gary henkel when he said: "much as i love imaging sciences, i use it and do consulting for them, what you were told is a lie"). this means that you are interested in my opinion and I thank you for this. what I said was not an attack on I cat, I don't have any problem with this machine (except one issue that I already discussed with you personnaly and I ask you to privatly contact me to tell you what is hapening about it), what I wanted to say was: in the absence of scientific studies supporting my or your or anybody's claims ( in this case proving that the performance of any diagnostic tool is superior to another one), saying that a given techniques is better than another, is pure marketing, it does it mean that it's a lie or it's wrong, it might be 100 % right but needs scientific back-up. Thank you
Arun Singh
4/4/2008
Dr. Noujeim: I was not making a direct judgment on the merits of the original statement, rather expressing the view that there was no motivation for an implant planning/surgical guide provider to do "pure marketing" for a specific product. The only logical basis would have been actual experience with the data itself. My primary intent was to differentiate this from statements from salespeople of a particular product. I certainly did not take it as an attack on the iCAT, however, I do have a question. Is your own statement (iCAT images are inferior in fact to two or three of them but I don’t want to mention names) based on a scientific study, and if yes, can we have access to the study?
Marcel Noujeim
4/7/2008
Mr. Singh We are conducting many research projects now but unfortunately I cannot give the results out, however, when results are ready to be published, this will be done as soon as we can and you have to understand that in my perspective if a machine is not performing well, this does not mean it’s the end of the world, we are in the beginning of a new era and cone beam machines are developing so fast now and there is a huge room for improvement. Mr. Singh You have to know that we are ready to work with all manufacturers (of course including I-cat as a PIONEER in this field and no body would dare to deny this fact) to improve the quality of our scans and this will be for the best for our doctors and our patients.
Anon
4/8/2008
FYI for all of you docs that will have a conebeam in your office. I'm looking at two cases as an expert where there was a failure to diagnose significant pathology (one maxillary sinus mass and one orbital floor lucency associated with a previous ZMC with orbital floor implant. You better have your CT's read by a radiologist or other radiological professional. You cannot disclaimer yourself out of liability outside the "dental structures". That motion was already denied and the case is proceeding. Simply taking a film for someone else and putting the responsibility on the party that ordered the film doesn't absolve the center at which took the film of responsibility. Radiology dental centers have some, granted little--but some insulation, as the center is not overseen by a licensed dentist or physician. If the place where the scan is taken has a licensed dentist or physician present, there is a responsibility for diagnosis. It could be as little as the radiograph is abnormal and referred for evaluation elsewhere, but doing nothing carries full failure to diagnose litigation. Some of these companies will tell you, you aren't responsible and give you a disclaimer to offer indemnity to the dentist. However, these will not withstand legal scrutiny as you cannot ever have someone consent to negligence and failure to diagnose is negligence. So be careful and wise when bringing these units into your practice, they are a great tool, but with it comes great responsibility. I believe these lawsuits are simply the tip of the iceberg and as the technology becomes more disseminated, so will the frequency of the suits.
Chris
4/14/2008
We have been looking at CBCT units for some time now. The image quality on the Prexion 3D seems to be best. Am I missing something here or is there just too few out because they are new to the dental market?
Bruce Hammond
4/14/2008
Anon, It troubles me that your "rep" only suggests the I-Cat machine but seems to think that it is the only one that utilizes the flat panel technology. Nearly all of the CBCT units on the market today are benefiting from this technology. There are only 2 major flat panel vendors in the world and they are Varian (from Salt Lake City, Utah) and Hammamatsu (from Tokyo, Japan). In fact, the Iluma and the I-Cat utilize the exact same panel from the exact same company. The real difference in each of these machines is how they acquire the data, normally referred to as the acquisition software. Another key element is the visualization software that you will use for patient consultation and evaluation. There are some great software packages out on the market today that offer you the ability to make surgical guides. A few of them are Simplant, E-Z Guide, and I-Dent. I believe that I-Dent is the easiest, lowest cost and fastest turn-around time. Utilizing this technology is very helpful but can be very frustrating when you are given inaccurate information from people that truely don't understand the technology. Please do not hesitate to e-mail me for any assistance or advise.
Teri
4/19/2008
ICAT are not the only company that produce large FOV CBCT. E-WOO does produce the Picasso Master series that produces 20 cm Dia by 19 cm height system as well. As for lateral ceph imaging, my feelings are that the high resolution 2D image are still the gold standard in imaging. You need a lot of justications to do a large 3D scan for orthodontic treatment especially for young patient
Teri
4/19/2008
Bruce, well said on your comments on the sensors, in addition to your comment, there are many factors to produce different image quality on the same sensor. The number of projections taken per scan, x-ray generator control, data read out techniques, image processing, reconstruction techniques and finally 3D software are the important factors to produce a good 3D image for diagnostics purpose.
Daniel
4/19/2008
Bruce, your comments were right on target.The NewTom VG has a 20 cm X 25 cm FOV
Andi
4/21/2008
I am thinking of getting a 3 in 1 system. So far, i know that there are 3 system in the market, a ewoo picasso, j-morita and planmeca. Can anyone advice me on which system should i go for and what is the difference.
Teri
4/21/2008
Hi Andi, As far as I know, J-Morita and Planmeca system have smaller FOV and the CT sensors have to be replaced by the Pano sensor when you are taking the Panoramic X-ray. It is not very clever as the possiblities of dropping and damaging the CT sensors are high. Replacement for the CT sensor are extremely expensive. Another thing you should do as to ask the sales agent to bring you to their installation site to see the system and look thru the images that have been taken in real clinical situations.
Daniel
4/21/2008
Andi: I agree with Teri regarding the J-Morita, changing these function is not easy. There are other good units available, NewTom has two units and as well as a mobile unit, Sirona has a unit as well as MyRay.
Julio Tojo
5/4/2008
I have got one of the first unitis of Galileos in Spain last year; my decesion was based on my previous experience with the orthophos from the same company and the service asystance. Maintenance is one of the most important issues, to my believe, when talking about similar quality. Price was also another point. At the begining software was not very efecient, now they have updated it and I am very satisfyed. May us, as clinicinians, identify the "sharp quality" diferencess the companies assert? I believe these also depends upon many other variables, even your own computer screen quality.
Marc
5/14/2008
I have heard that the i-cat needs 2 hours of warm-up before using, acuare 2D images out from an CT scan, meed calibration every day and have a higher does of radiation - Does anyone nknow if this is true? The J - Morita and Picasso does not need any warming up, no calibration, have a OP sensor and have lower radiation. Can any one help me with above question. Then it will make my desicion easier on which machine I schould buy.
Arun Singh
5/15/2008
The iCAT does not need any warm up time, the 2-hour warm up time applied to the earliest model that was intorduced in early 2004. The warm-up requirement was eliminated about 2 years ago. The new generation iCAT, intorduded last summer, no longer requires daily calibration. It does require a weekly calibration, which takes less than 5 minutes. However, this particular type of calibration, known as "panel calibration", must be done on any system utilizing a flat panel. As far as the radiation, the iCAT dose is one of the lowest of all systems on the market, based on independently cunducted and published studies. In response to one of the earlier comments by Daniel, quoted here: "Bruce, your comments were right on target.The NewTom VG has a 20 cm X 25 cm FOV" These dimensions apply to the sensor (flat panel), not the FOV. The actual FOV is much smaller, perhaps around 13cm x 16cm. However, the iCAT provides a much larger FOV of 23cm x 17cm for cephalometric coverage, utilizing a special method to extend the FOV. Arun
Richard Benian
5/16/2008
My practice, OMFS, is looking into getting a cone beam CT machine. Frankly, the information I have gotten is confusing. I am trying to find out as much as I can about the machines on the market and would appreciate any comments about any machine. I would really like to hear about image quality, software support or lack of it, software capabilities/limitations, maintenance issues, ease of use, etc. Any horror stories about any company and its machine would be nice to hear about too.
Dr SDJ
5/18/2008
Dr Julio Tojo raised a very valid point-"I believe this also depends upon many other variables, even your own computer screen quality. " Even with the best equipment supplied by the company, there can still be many more variables one was not prepared to come accross. 'Quality is Multi-factorial'. FOV and radiation dose and 16 bit flat panel etc. may all be very good to know at the back of the mind. But purchase decisions are and should be influenced more by facts beyond the "hardware wiring" like for example the post sale service, ease of repairs and availabilty of spares, "is the company going to be around in next 7-8 years time etc. The nuts and bolts aren't every thing in dentistry.
Bruce Hammond
5/30/2008
Richard Benian, I understand your fear of purchasing such an expensive piece of equipment. I would be happy to visit with you via e-mail and/or a conference call to discuss the different machines on the market, horror stories associated with the parent companies, etc. I can assure you that I am a very unbiased insider in this industry and am happy to help you out. Please e-mail me at brucehammond7074@yahoo.com if you are interested. Thanks.
sergio pimentel
7/15/2008
DEAR SIR I AM A MAXILO FACIAL SURGEON , IN ARGENTINA , I AM TRYING TO PURCHUSE A UNIT ( CONE BEAM) ORIENTED TO IMPLANT PLANNING / 3 D PROTOTYPING FOR ORTHOGNATIC SURGERY AND ORTHODONTICS 3D DIAGNOSIS AND PLANNING ( PROTOTIPYING), WHICH IS YOUR OPINION IN TERMS OF THE NEWTOM 3G VS PICASSO TRIO AND PICASSO MASTER, TNANK FOR YOUR ATTENTION AND SUGGESTIONS
Dr. Venci
7/16/2008
I have had experience with several of the machines mentioned here and my preference is indeed with the i-CAT. One lab I tried used the NewTom VG, and another had the Iluma, and at the ADA I checked out JMorita's machine, and Sirona's. I'm sorry but the software files are too big on these machines, and the surgical predictability isn't what its cracked up to be. If your like me and fear drilling through the mandibular ridge into the IV or perfing the sinus, the iCAT is the only choice. The others claimed to be a 1 to 1 image, but those are just reps blowing steam. The support I get is the other big winner, the last iCAT Vision update put another huge gap between them and the others. One NewTom image I got was so far off I had to send the patient home after I opened the flap! These other companies, except hitachi, seem to be bought and sold like peanuts.... why is that?
Dr. Wadley
7/17/2008
What is amazing to me is you have people posting all kinds of false information. Arun Singh is the imaging manager for iCat. Bruce is a dealer for NewTom who has sent out information that is downright false. How about being a little less biased and posting information that is helpful and not slanted to your specific product? Most of the Dr.'s that are asking questions want to be educated on the technology, not sold your specific product.
dr simmons
7/19/2008
I agree, but I don't think either Bruce or Arun are sending out information that is false. Generally, you can argue these points for a very long time. I'm personally an i-CAT user, and I've been very happy. I'm upgrading this fall, to the latest machine. I've done my research and I can see where Bruce and Arun make good points. What is it you find so abnormal Dr. Wadley? At the ADA last year, the iCAT clearly was the best machine, and while there are a ton of great images from a lot of machines, none are true 1 to 1 images except iCAT... 3D that is. You should be happy with any machine you get, and if your relying on a blog to become educated, that's fairly lazy my friend. Don't your patients deserve some research on your behalf that is hands on? Go network and formulate your own opinion. My only advice is to make sure you're buying from a company that gives great service and has a lot of customers. Best of luck!
Randall Morgan DDS DMD
7/19/2008
If you go and get hands on experience with these machines, your questions will be answered. The differences aren't as big as you think, but generally the more glitz and glamor you get at a demo, the more they are hiding. They all have weaknesses, and strengths, but a few are far above the rest. You'll get fancy pictures with all of them, but its up to you to decide which is fluff and mirrors, and which is really accurate. Or go to a neutral source, like a software provider, Simplant, or Dolphin, or check out what Suresmile says .... I talked to each of these companies tech support before I made my decision, they know what is real and what is propoganda.

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