CT colonography (CTC, or virtual colonoscopy) is a highly sensitive and specific test for detection of polyps larger than 1 cm. Multiple studies have shown similar accuracy when comparing CTC to conventional optical colonoscopy (OC) both in high-risk groups and, more recently, in a low-prevalence screening population.1-4 Due to the accuracy, safety, and lack of invasiveness, CTC is an effective and well-tolerated diagnostic procedure for patients who cannot endure or complete OC, as well as a viable alternative screening test for the detection of colorectal polyps and cancers. However, many issues relating to clinical implementation remain as CTC completes the transition from an evolving technique to a generally accepted screening test. These issues relate to the appropriate indications for use, third-party reimbursement, economics of delivery, and improvements in technology.

Indications for Use

The indications for the use of CTC can be separated into three primary areas:

  1. as a completion study following a failed OC;
  2. evaluation of individuals with symptoms of colonic malignancy; and
  3. screening of asymptomatic individuals.

Currently, at Partners Health Care—Massachusetts General Hospital (MGH) and Brigham and Women’s Hospital (BWH)—the most common indication for CTC is as a completion study following a failed or incomplete OC. This indication has been readily adopted by most gastroenterologists because of the realization that the nonvisualized portion of the colon following an incomplete or failed colonoscopy represents a significant health risk to the patient as well as a significant medical liability risk to the gastroenterologist. In addition, the ability to perform CTC immediately following the failed OC obviates the need for the patient to undergo a second bowel prep, as had frequently been the case when completion studies were performed with barium enema.

Pedunculated polyp and corresponding view in the colon.

Patients who present with the triad of weight loss, anemia, and blood in the stools frequently will be evaluated with a combination of endoscopy and CT of the abdomen and pelvis. The ability to evaluate both colonic and other noncolonic abdominal malignancies with a single CTC examination has great potential value in terms of diagnostic efficiency and convenience. However, the role of CTC as a sole means of evaluating patients who present with signs and symptoms of colonic malignancy has not been fully evaluated against the combination of OC plus CT of the abdomen and pelvis. Once a colonic neoplasm has been identified at video colonoscopy, and if that lesion prevents passage of the endoscope, CTC is an excellent method of evaluating for both the presence of synchronous colonic polyps/malignancy and the staging of the detected neoplasm, both within the colon and throughout the abdomen.

Screening of asymptomatic individuals with CTC remains a controversial subject among gastroenterologists, radiologists, health care policy advocates, and third-party payors. In our experience, most gastroenterologists agree that CTC is clearly the best screening alternative second only to OC. Sufficient

evidence to date shows that CTC outperforms both the barium enema and flexible sigmoidoscopy. But unfortunately, the political climate around radiology-gastroenterology turf battles has prevented CTC from taking its rightful place among the screening alternatives. One of the developing indications for use, which is gaining support among our own local gastroenterologists as well as gastroenterologists nationwide, is as a primary screening test in patients who are either unable or unwilling to undergo OC. It is hard to argue that any other screening test (such as the barium enema or flexible sigmoidoscopy) would be preferred in this patient population. Indeed, published data clearly demonstrate patient preference for CTC over either barium enema or optical colonoscopy5; sigmoidoscopy does not provide the “total colon examination” recommended by such organizations as the American Cancer Society. Patients at increased risk for bleeding or respiratory complications during OC could clearly benefit from CTC as an alternative to OC, as CTC has such an excellent safety profile. Patients who could have an increased risk when undergoing OC include patients on anticoagulation therapy that cannot be withheld; or patients with bleeding diatheses, severe cardiopulmonary disease, previous failed colonoscopy, or previous perforation with OC. Unfortunately, (as described below) Medicare will not cover CTC when used as a replacement for screening OC.

Sessile polyp with corresponding views in the colon, solid and transparent. All images courtesy of Matthew A. Barish, MD, Brigham & Women’s Hospital, Boston.

Reimbursement and Economics

Two new Category III Current Procedural Terminology (CPT) Codes—0066T and 0067T, which describe CTC for screening and diagnostic purposes, respectively—were released in July 2004 and went into effect in January 2005. Category III codes are used to describe emerging technology and now prevent physicians from using the standard Category I CPT codes for either CT unlisted procedure or CT of the abdomen and pelvis, plus the 3-D reconstruction add-on code, CPT 76377, to describe and bill for a CTC. This is because CPT specifically instructs physicians to use the most specific code that accurately describes the service provided; use of less-specific Category I codes could be inappropriate and can be construed as fraud. The current state of reimbursement for screening and diagnostic CTC in 2006 is discussed below. The reimbursement situation for CTC is very limited at present, but hopefully, reimbursement will improve in the future as the procedure gains wider acceptance.


Harvard Virtual Colonoscopy Course

September 28–29, 2006, in Boston at The Conference Center at Harvard Medical. The course offers didactic lecture, hands-on training, and case review. For more information, visit www.virtualcolonoscopy.org/Training.htm.

Medicare reimbursement. Screening CTC (CPT 0066T): Because all services must be coded at the highest level of specificity, CTC for screening purposes must be coded under the new Category III code of 0066T. Unfortunately, only designated screening benefits are covered by Medicare. Such screening benefits are set by Congress and are not at the discretion of CMS or its local contractors. Screening for colorectal cancer is one of the screening benefits covered by Congress; however, CTC is not one of the tests that Congress approved. Therefore, all local Medicare carriers will universally reject this reimbursement for screening CTC billed under 0066T. Thus, professional billing (0066T-26 modifier) under the Medicare Physician Fee Schedule (MPFS) has zero Relative Value Units (RVUs) assigned for radiological reading of screening CTC, and both the MPFS and the Hospital Outpatient Prospective Payment System (HOPPS) have no reimbursement assigned for the technical component of screening CTC under CPT 0066T.

Diagnostic CTC (CPT 0067T): The reimbursement situation for diagnostic CTC (0067T) is highly variable, and each state has a local coverage decision (LCD) that determines whether the procedure is reimbursable. The multitude of LCDs can be summarized into one of four categories:

  1. Universal rejection of all Category III codes, including CTC (0067T);
  2. Limited coverage only when video colonoscopy of the entire colon is incomplete due to an obstructing lesion resulting in an inability to pass the colonoscope proximally;
  3. Limited coverage only when video colonoscopy of the entire colon is incomplete due to several limited listed indications; or
  4. Coverage for those patients in whom an instrument colonoscopy of the entire colon is incomplete for all indications that result in incomplete colonoscopy.

Since the LCDs can change based on new evidence and input from local physicians, individuals are encouraged to view the current LCDs by going to the CMS Web site (www.cms.hhs.gov/mcd/search.asp) and entering the state and appropriate CPT code for CTC (0067T).

The professional reimbursement (0067T-26 modifier) for diagnostic CTC, as well as the technical component (0067T-TC) on the MPFS, are both listed at zero RVUs in the 2006 CMS final rule, although certain regional carriers have agreed to pay for professional billing of diagnostic CTC under certain circumstances. The technical component is billed through the MPFS only when the scanning occurs at a nonhospital setting, such as an imaging center owned and operated by a radiology group practice where global billing applies.

When diagnostic CTC occurs within a hospital setting, wherein the technical components for outpatient scanning procedures are billed through HOPPS, the outpatient technical component is reimbursed under the ambulatory payment classification (APC) group assigned for the CPT code. Originally, when the APC assignment was made for CPT 0067T in 2004, the code was placed in APC 0332 at the same technical reimbursement as CT noncontrast examinations. However, diagnostic CTC has significant additional expense in comparison to a standard noncontrast CT examination as discussed in detail below. Furthermore, diagnostic CTC is performed with contrast in about one third to two thirds of the cases—based on experience at our institutions—and this was not accounted for by the noncontrast CT reimbursement classification. This assignment, which was made in the absence of any prior single-procedure claims data by CMS, was inappropriately low and did not account for many additional costs involved in diagnostic CTC relative to CT noncontrast examinations. Therefore, in January 2005, we submitted comments to the APC Advisory Panel and presented our concerns at the group’s subsequent meeting. In 2005, the APC Advisory Panel moved diagnostic CTC from APC 0332 (noncontrast CT) to APC 0333 (CT without followed by with contrast), resulting in an increase in the national average hospital outpatient APC technical reimbursement from $188 (APC 0332) to $304 (APC 0333).

Local Insurance Carriers. The coverage landscape for local private carriers is even more variable and confusing than it is for Medicare. Each carrier has developed individual coverage rules that range from no coverage for CTC under any circumstance to full acceptance of CTC as a replacement primary screening tool that competes directly with video colonoscopy, barium enema, or flexible sigmoidoscopy. Several large major carriers are now reviewing their policies and the financial impact of offering CTC as a covered service.

Patient Self-Pay. Over the past few years, the demand for CTC by patients who are willing to self-pay for the service has dwindled. In our facility, these patients make up only a small minority of the total of CTC cases performed. Many reasons can explain the decrease in self-pay patients presenting to many centers. First, a large majority of the health-conscious, motivated population interested in CTC screening with financial means to self-pay have already undergone screening during the previous years that CTC has been offered. Also, increased availability of CTC among centers has decreased the volume at any one individual center. Furthermore, a general backlash against the concept of whole-body CT screening might have adversely affected the public perception of CTC.

Reimbursement Codes

Two new Category III Current Procedural Terminology (CPT) Codes have replaced the previous method of billing for CTC. They are:

  • Screening CTC: CPT 0066T—All local Medicare carriers will reject any CTCs billed under this code, because Congress has not approved the test for screening colorectal cancer. No Relative Value Units are assigned for professional reimbursement.
  • Diagnostic CTC: CPT 0067T (technical)—Indications are highly variable by state, so check the CMS Web site (www.cms.hhs.gov/med/search.asp). Under the Physician Fee Schedule, CPT 0067T-26 modifier (professional) and the technical component, CPT 0067T-TC, are listed at zero RVUs in the CMS final rule for 2006. Although no RVUs are assigned, some private payors will reimburse for professional fees under some circumstances.
  • APC 0333 (hospital-based outpatient setting)—Last year, the APC was upgraded to CT without followed by with contrast for technical reimbursement, at approximately $304.

Development of a CTC Service Line

The development of a successful CTC service not only requires an understanding of the clinical, technical, and interpretation issues but also requires a complete understanding of the management, business, and economic implications of implementation. The establishment of a new service line can benefit from incorporation of several standard business planning elements.6 Ideally, a new CTC service line should fit seamlessly into the overall plan for colorectal-cancer screening and requires input from primary care physicians, gastroenterologists, and radiologists. To foster a collaborative environment, gastroenterologists might need to be reassured that the goal of implementing a CTC program is to target the population who is not currently undergoing appropriate screening and that the goal is not to dissuade patients from undergoing video colonoscopy. With this in mind, CTC should, in fact, increase the overall screening rate with a net effect of increasing the total number of diagnostic video colonoscopies performed for polypectomies.

The formation of an effective CTC service will require an investment in personnel, equipment, and education. When planning a CTC service, one should strongly consider hiring a program coordinator. The role of this person is to coordinate scheduling and patient referrals, and answer patient/referring physician inquiries regarding the procedure, preparation instructions, indications, and contraindications. Because this test is relatively new, inquiries in this area can be quite time-consuming, and a facility’s current schedulers and CT coordinators likely will be unable to handle the additional burden. In the early stages of program development, additional CT technologist staff likely will be unnecessary until the volume of cases increases significantly. Well-trained technologists should be able to perform the procedure with minimal increase in time above other standard CT procedures.

Additional equipment for CTC will fall into one of three categories:

  1. preparation material (laxatives, stool tagging agents, and low-fiber food supplements);
  2. insufflation supplies (CO2 insufflator, CO2 tanks, connector tubing, lubricant, and enema tips); and
  3. an interpretation workstation.

Typically, the costs of the preparation material will be at the patient’s expense, although provision and packaging of a complete bowel preparation kit, including instructions, could increase compliance. The contents and cost of such a kit might be as follows: laxative ($2–$10); Tagitol V: barium tagging agent ($25); and NutraPrep prepackaged low-residue meal plan ($21)—for a total of $50. Insufflation supplies represent the major cost of consumables in providing a CTC service. At both BWH and MGH, we perform nearly all of our CTC studies using carbon dioxide due to the perceived greater patient comfort following the procedure, ease of an automated system, and the reproducibility of insufflation pressure monitoring. However, use of CO2 comes with a price. One must include the additional capital purchase of a CO2 insufflator (list price is approximately $9,900), plus the operating expense of CO2 tanks ($20 per tank for approximately 200 patients) and insufflator tubing ($19 per patient). Finally, in approximately one third to two thirds of diagnostic CTC examinations, intravenous contrast material is used to assist in clinical interpretation, adding $10 to $40 to the cost of the procedure.

The choice of an interpretation workstation is complex, and will depend on radiologist preference, preexisting workstations, institutional-corporate relationships, and cost. Radiologists frequently have a strong opinion regarding which workstation provides the best strategy for interpretation. In many cases, this opinion is biased by what workstations they have used in the past—as opposed to a careful review of what is available. The rapid pace of development by workstation manufacturers also has added complexity to the decision-making process. In addition, for those centers with preexisting relationships with manufacturers, and for those who already own a modality workstation, the decision will be affected by the cost of a software upgrade rather than the complete purchase of a new workstation. List prices for CTC workstations can vary from $35,000 for software only to several hundred thousand dollars for a complete new modality workstation incorporating a CTC package.

The last cost for developing a new CTC service relates to the training of radiologists and technologists. An emerging consensus states that one of the most important factors affecting the quality of CTC is the training of the radiologist interpreting the examination.7

Many centers, including our own (www.virtualcolonoscopy.org/Training.htm), offer hands-on training to allow radiologists the opportunity to review actual CTC cases with pathologic proof directly on workstations in a hands-on supervised manner. These courses are essential to provide the specific training necessary to interpret CTC examinations.


CTC is an effective means of evaluating the colon both in symptomatic patients and in the screening population. CTC outperforms all other diagnostic and screening tests for colon polyp detection other than conventional video colonoscopy. However, the political and economic climate has prevented CTC from reaching wide acceptance among the screening guidelines. Even with the lack of reimbursement from major third-party payors, CTC continues to gain in popularity, with increasing numbers of providers offering the service. Gastroenterologists, primary care physicians, and patients have begun to recognize the value of CTC in certain key clinical areas.

CMS and other insurance carriers now have begun to offer coverage for CTC in many of these areas. Collaboration between gastroenterology and radiology will be necessary for CTC to be accepted as a primary screening method in certain clinically appropriate patient populations. Once CTC is adopted, radiologists must familiarize themselves with the economics and business principles of offering an effective CTC program.

Matthew A. Barish, MD, is director, 3-D & Image Processing Center, director, International Symposia on Virtual Colonoscopy, Brigham & Women’s Hospital, and assistant professor of radiology, Harvard Medical School, Boston; Michael E. Zalis, MD, is director, CT Colonography, Division of Abdominal Imaging and Intervention, Department of Radiology, Massachusetts General Hospital, and assistant professor of radiology, Harvard Medical School, Boston; and Gordon J. Harris, PhD, is director, 3-D Imaging Service, Massachusetts General Hospital, and associate professor of radiology, Harvard Medical School.


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