Low dose CT Revolution scanner

Seattle King5 TV’s Jean Enerson reported recently on UW Medical Center’s installation of the GE Revolution CT scanner.

Revolution CT scanner

The new technology of the Revolution features the following:

  • Much longer and wider detector
    • (16 cm vs. 4 cm)
  • Much faster rotation speed and scanning
    • (0.28 seconds – 70 G’s centrifugal force)
  • Much better radiation dose lowering technology
    • ASIR-V, auto kVp, density modulated auto mA

16 cm wide-detector array: Whole organ scanning on one 0.2 second rotation

Currently, the Revolution CT scanner is being used at UW Medicine for scans of the heart, blood vessels, and organs that involve more than one pass and the evaluation of transplanted organs. In the future, we intend to expand further into:

    • TAVR
    • All aortograms
    • Cardiac
      • coronaries, perfusion, congen., ablation
    • All misc. vascular studies
      • Renal arteries, HA, runoffs, carotids, COW, grafts/stents, venograms
    • Non-Dual-Energy multi-pass exams
      • Liver, pancreas, IVP
    • Perfusion (brain, transplants, tumor)
    • Workhorse (CAP, KUB, brain, spine)


Update Needed for CCTA Training Guidelines

The following passage, from an article on HealthImaging.com, caught my attention:

The honeymoon has ended for coronary CT angiography (CCTA) and the seven-year itch has commenced for some radiologists and cardiologists. They do not advocate replacing the technique though. Rather, they are asking if the requirements in training guidelines need a makeover to reduce variability and better maximize CCTA’s potential to improve patients’ clinical care and outcomes.

This brings up a good point: the credentialing criteria for performing and interpreting cardiac CT are now too low. I found the learning curve was long with a gradual slope. You need to be in a training and supervised environment with a fairly good case load for at least a year. It’s challenging, but performed well and interpreted with skill, it is a very valuable test which can save the healthcare system considerable cost – especially in low- to moderate-risk chest pain patients presenting to an emergency room.

When It Comes to Cardiac CT, Specialized Credentialing is Essential

The topic of cardiac CT credentialing came up at the recent International Society for Computed Tomography meeting and raises interesting points on the specialized training. Some wonder with the comprehensive residency and fellowship training that’s required to earn the title of “radiologist”, just how necessary this special credentialing for cardiac CT is. Dr. U. Joseph Schoepf of the Medical University of South Carolina points out that it is essential and ideal for cardiac imaging.

Schoepf notes, “The truth is that cardiac CT is the new kid on the block for many practitioners who finished their training more than a decade ago.” He went on to say that anyone who wants to read cardiac CT needs special training, but “there aren’t enough institutions out there that have enough volume in cardiac CT to really appropriately train residents and fellows.”

Dr. Schoepf is 100 percent correct. Cardiac CT requires relatively extensive subspecialty training plus a fair amount of experience for proficiency. Even a Board Certified Radiologist can’t pick it up overnight or at a weekend course.

Subspecialty certification and re-certification after an appropriate time are very good initiatives. A Certification of Added Qualification (CAQ) in cardiac CT is just as meaningful as one in Pediatric Radiology or Interventional Radiology. It provides some assurance about a radiologist’s level of knowledge and practice excellence.

To read more about the importance of experience when it comes to CT, please click here.

CT Scans CAN Be Cost Effective (and Save Lives) in Emergency Situations

A recent study found that the use of CT scanners and other advanced imaging machines in U.S. hospital emergency departments “tripled between 1998 and 2007, resulting in higher costs and longer emergency room stays,” according to an article by blogger Julie Steenhuysen.

Lead researcher Dr. Frederick Korley of Johns Hopkins Medicine in Baltimore said his team noticed “a really significant increase [in usage] without a corresponding increase in the diagnosis of life-threatening illness.” He said this suggest that there is a “potential amount of overuse or use that is not directly yielding any meaningful clinical results.”

Actually, the use of all CT and MR from any source more than doubled during that time period.

Emergency rooms are under great pressure to diagnose or rule out serious conditions quickly, since every ER in the country is swamped with patients – many of whom cannot get to other forms of care. What is inappropriate in some settings may be appropriate in the ER setting.

In our study of patients with low-risk chest pain who had a cardiac CT early in their ER visit, patients were discharged 20 hours faster and with a 40 percent cost reduction compared to similar patients who had a workup without cardiac CT.

So it really depends on the indication.

Study Published in American Journal of Roentgenology

The October issue of the American Journal of Roentgenology has just been released, and it features a recent study I conducted with blog contributor Janet Busey and colleagues Kelley Branch, Lee Mitsumori, Jared Strote, Douglas Green and James Caldwell.

The study, “Negative ECG-Gated Cardiac CT in Patients with Low-to-Moderate Risk Chest Pain in the Emergency Department: 1-Year Follow-Up,” shows that for patients with low-to-moderate risk chest pain evaluated in the emergency department, adverse cardiac events may be rare during the year after a negative cardiac CTA scan.

To read the study, click here (a subscription is needed to read the full article, though you can view the abstract for free).