Dedicated lab takes advantage of 3D imaging capacity

Busy schedules may prevent radiologists from taking full advantage of 3D imaging data, so the 3D Imaging Service and Radiology Computer Aided Diagnostics Laboratory at the Massachusetts General Hospital is stepping up to the postprocessing bat. The lab uses a full-time staff to provide support to radiology departments and the rest of the hospital.

One of the lab's goals is to migrate new 3D technologies into clinical practice, thereby bridging research and clinical applications, according to director Gordon J. Harris, Ph.D., who spoke Tuesday at the Radiology into the 21st Century congress in Boston.

The lab's 13 employees include director, operations manager, administrator, technical staff, 3D technologists, image analysis specialists, and 3D ultrasound technologists. The staff perform postprocessing for about 100 exams per day:

* 25 MR angiograms

* 30 CTA

* 20 other CT and MR

* 25 ultrasound

The lab applies a variety of postprocessing techniques to images, including multiplanar reconstruction, oblique and curved reformat, maximum intensity projection, shaded-surface display, volume rendering, endoluminal views, functional imaging, and CADx, both segmentation and quantitation.

One of its clinical applications is the production of 3D functional MR brain images to help neurosurgeons plan surgeries. Harris described the scanning of patients who were asked to flex their hands during the exam. This allowed the lab to develop 3D fMRI maps that highlighted the motor regions of the brain, areas which neurosurgeons wanted to avoid during surgery.

The lab also performs virtual hepatectomies using CADx, defining the surgical plane in 3D space and leaving sufficient volume for regeneration. Determining the appropriate amount of liver to remove for a transplant was largely a matter of guesswork in the past, Harris said.

"Three-D radiology provides more comprehensive and realistic views of the patient, faster and more confident diagnoses and treatment planning decisions, and reduced need for exploratory surgery," he said.

While a separate code exists for 3D reconstruction billing, some problems arise. Ambulatory payment classification reimbursement is set relative to claims data. Only 40% of hospitals charge more for CTA then CT. In fact, most hospitals charge less, Harris said.

"Reimbursement for CTA was only $5 more than CT in 2003 and $24 more in 2004, and it will actually be $3 less in 2005," he said.

Harris proposed that the amount for CTA reflect the sum of charges for CT plus the charges for the additional 3D postprocessing, which is now routinely applied. If the CT charge is $1200 and the 3D postprocessing is $400, then the hospital should charge $1600 for a CTA.

In the future, the lab plans to step up services to support the needs of many hospitals and imaging centers.

"The ultimate result of this new technology is improved patient care, increased clinical confidence, and reduced time, cost, and invasiveness," he said.