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In science fiction movies, the patient getting a checkup lies supine while the futuristically clad physician passes a wand over his body. Mysterious lights flash in the background, and in a single, unified process the patient is both evaluated and healed.
It is not too much of a reach to suggest that the first step—evaluation—is within radiology’s grasp. CT, MR, x-ray, ultrasound, and the other modalities can sniff out budding diseases with impressive certainty. Even so, with the exception of mammography, thorough radiological disease screening of the public at large may be a long way in the future. The impediments are daunting, and with few exceptions, payors are keeping their wallets pocketed.
Self-paying patients have not knocked the doors down either. Whole-body CT imaging centers, which opened with much entrepreneurial fanfare, have often failed to attract self-paying customers,1 and the American College of Radiology does not endorse this kind of walk-in scanning.2 Currently, however, there are a number of radiological screening procedures for specific disease states that are under investigation. Experts in a few key radiological screening examinations are advocating for their tests to be accepted as screening tools for certain defined populations of asymptomatic patients. They would like the screens to be adopted and reimbursed broadly, as breast cancer screening is now.
 Figure 1. Targeted view of a small nodule in the right lung in an asymptomatic patient with a positive CT screen. Although small, this was an advanced stage lung cancer. Courtesy of Denise Aberle, MD, UCLA Medical School. |
One of the impediments to making this a reality, however, is that many of the screening tests, in a formal, scientific sense, remain in the investigatory stages. Bruce Hillman, MD, FACR, is a professor of radiology at the University of Virginia. He is also the chair of ACRIN, the American College of Radiology Imaging Network. ACRIN is involved in 22 clinical trials, Hillman says. Two of those trials—the National Lung Screening Trial (NLST) and the National CT Colonography Trial (ACRIN 6664)—are particularly germane to this story because they may shape future policy for lung and colonic cancer screening.3
Hillman is succinct in explaining why broad-based screening for any disease is a difficult proposition.4 “We believe only one image screening technology (breast cancer mammography) has been scientifically proven to reduce the mortality rate,” he says. “That’s the bottom line for screening, does it change the mortality rate? The reason that’s the bottom line is because screening turns out to be very, very expensive. You have to image a very large population to find a very small number of people.”
And the expense of imaging lots of people to find a few with disease is only one cost, Hillman adds. There is also the cost of following up on false positives. “For most screening, the false-positive rate turns out to be pretty significant,” he says, “and all those people need additional work-up, and there will be some morbidity and some wrong treatment, so that’s very expensive as well. No matter who’s done the study, screening almost always adds cost.”
So screening, Hillman says, can be justified only if it saves lives. And even then the cost per saved life has to be taken into account, he adds.
“If you look at some of the decision analysis, for instance, on lung cancer screening by CT, you find the cost as little as $2,500 per year of life saved, and that’s a real bargain if it’s true, but you’ll also find articles that place it around $120,000 per year of life saved, and that’s very high.”
Hillman says the cost analysis includes the expense of treatment, surgery, and all the other downstream expenses that follow from a screening program as well as the screening cost.
“Generally, we say if the cost is only around $50,000 or below that, then we ought to consider doing it,” he says, “and at this point in time the only examination we know that saves lives at a reasonable cost is mammography.”
Hillman’s analysis helps explain why virtually no imaging screening for asymptomatic patients is being reimbursed now by private payors or by Medicare except for mammography. Most asymptomatic patients being screened now are the so-called worried wealthy or worried well who are paying for their own screenings. Some insurance programs for executives also have a generalized preventive screening component, but these too involve low numbers of people.
Of course, there is another population group being screened and that is those people involved in clinical trials. These patients may be the lucky ones, helping to prove the life-saving benefits of screenings that will one day be carried out more broadly, probably on segments of the population defined as being at high risk for a given disease. A look at the major radiological screening efforts under way, however, shows what a complex proposition screening is.
LUNG CANCER
This year, according to the National Cancer Institute (NCI), lung cancer will kill more than 163,000 Americans. That is about a third of all cancer deaths, and lung cancer by itself claims roughly the same number of lives as does stroke.5 It is a major killer, and costly too. Smokers are responsible for much of the cost. According to a recent report from the Centers for Disease Control and Prevention (CDC), smoking deaths cost the nation about $92 billion in lost productivity alone between 1997 and 2001, a span that saw 440,000 smokers die prematurely. The same report says that 32 million Americans continue to smoke.
Despite the high number of lung cancer deaths, there is no recommended screening procedure to identify the disease early on. In May 2004, the US Preventive Services Task Force (USPSTF) concluded that “evidence is insufficient to recommend for or against screening asymptomatic persons for lung cancer” with any test, including low-dose CT and x-ray. However, a clinical trial begun in 2002 may change things.
 Denise Aberle, MD |
Denise Aberle, MD, is professor of radiology and chief of thoracic imaging at the UCLA Medical School. She is also principal investigator in the National Lung Screening Trial.
The NLST is a huge trial being conducted by the NCI and ACRIN. It will eventually screen 53,000 current or former smokers between the ages of 55 and 74 who have never been diagnosed with lung cancer.
Participants in the trial are randomly assigned into either an experimental group, which is scanned with low-dose CT, or a control group, which receives conventional x-ray.
“That’s the primary end point we’re looking at,” Aberle says, “which of these two tests better lowers lung cancer deaths in a population at high risk for lung cancer.”
As matters now stand, she says, CT appears to be “three to five times more sensitive in finding small nodules than a chest x-ray would be.” There is a problem, she adds: “The great majority of these CT-detected nodules are benign, which converts many ostensibly healthy people into patients who now require some form of additional evaluation.”
CT also appears to be detecting more lung cancers than chest x-ray, most of which are early stage lesions. “Although that would seem to be a good thing, there is currently nowhere any data showing that with CT screening you actually see a decrease in the number of late-stage, lethal cancers,” Aberle notes. CT screening is more sensitive, but the screening itself has not yet been shown to save lives better than screening with x-ray.
The NLST participants will be screened annually for 3 years and followed to determine their health outcomes as far as 2009, Aberle says. By the end of the study, researchers hope to determine if fewer individuals with lethal cancer are showing up in the CT group than in the x-ray group, proving that CT screening for lung cancer does save lives.
“The good-case scenario is that CT in fact will pick up some cancers that if treated early will reduce lung cancer mortality, and that’s our hope,” Aberle says. But there is a bad-case scenario too, she says. CT may be so sensitive that it is picking up extremely slow-growing cancers that are not actually harmful, while not actually reducing the number of advanced cancers.
Aberle says she wants proof that CT screening does save lives before she endorses it for generalized use at UCLA.
“I don’t have a screening program outside of the NLST,” she says. “I don’t offer screening. If a patient is referred by a physician for a screening examination, then I’ll do a low-dose helical CT on them, but that doesn’t happen very often because we don’t offer it, and don’t advertise it. At this point I can’t recommend any form of screening for public policy.”
She says imaging centers that offer CT lung cancer screening to self-paying patients have latched onto “a fairly effective way to establish a business, but it’s not necessarily in the interests of public health.” The “downstream complications” from such imaging, notes Aberle, are yet to be weighed. Nobody wants to talk about them, she says.
There are potential risks to lung cancer screening. “In recent trials, up to one in five people undergoes surgery for a benign nodule,” she says. “Some people don’t want to be followed and told, ‘Well, if it hasn’t grown for 2 or 3 years, we’ll know you’re OK.'”
She also notes that some benign tumors grow. “Growth is an indication of malignancy by CT or x-ray criteria, so even our criteria for what is benign or malignant with imaging are not infallible. You can also biopsy indeterminate nodules, but sometimes the nodules are small. So if you get only benign cells, you sometimes don’t know if it’s a potential sampling error, if you just missed the malignant cells.”
 Figure 2. CTA shows a totally occluded left anterior descending artery. Images courtesy of Melvin E. Clouse, MD, Beth Israel Deaconess Medical Center. (Click the image for a larger version.) |
That is why some people find it safer, she says, “to go in with a surgeon and just cut it out, it’s more definitive.”
She also notes that surgery may be performed on slow-growing cancers that would never be life-threatening and that chemotherapy may be given to patients who do not need it.
“We give combination therapies to people, even with early stage disease, because their survival statistics are better. So now you may receive cytotoxic agents for something that you didn’t need it for,” she says. “That’s what I mean by complications.”
She says that UCLA does screen with CT and chest x-ray for lung cancer in some executive health programs and that she will screen individuals with CT referred by a physician who have made a personal decision to be screened knowing the uncertainties and risks. But that should not be confused with advocating CT screening as public health policy, she says.
“I don’t presume to craft public policy, but I do presume through the NLST to rigorously study and provide data accurately for the American public to craft its own health policy,” she says. “That’s what we’ve set out to do.”
In the meantime, she says, most physicians who do lung cancer screening still use chest x-ray—even though there is insufficient data yet to prove that chest x-ray reduces the lung cancer death rate.
“About half of general physicians and many pulmonologists still get annual chest x-rays on their smoking patients,” she says. “It’s entrenched in our practice because of the great desire to stop lung cancer. The NLST should provide us with facts to support (or not support) that practice.”
HEART ATTACK
“Did you hear me when I said more people die prematurely from cardiovascular disease than they do from the second through the seventh leading causes of death? That’s all cancers, infections, murder, death on the highway—and it’s the only disease you can really do something about.”
 Melvin E. Clouse, MD |
Melvin E. Clouse, MD, is a professor of radiology at Harvard University and vice chairman and director of research at Beth Israel Deaconess Medical Center in Boston. He may get slightly irascible when asked almost the same question twice, but the point is worth repeating.
In 2002, according to the CDC, heart disease killed nearly 700,000 Americans, a little more than half of them women. Most men have heart attacks in their 60s, women in their 70s. But many of both genders die younger than that. Stroke killed an additional 62,000. Overeating is the culprit, Clouse says, and he would like to do something about this preventable carnage. He says CT cardiac calcium scoring, widely applied, could help. Some people would receive intervention, while those with less severe stenosis could be given drugs and/or dietary and lifestyle advice that might save their lives.
But much to Clouse’s dismay cardiac calcium screening is not being widely reimbursed.
The Preventive Services Task Force recommends against screening for calcium with electron beam computed tomography (EBCT). Its rationale is that unnecessary false-positive interventions could cause more harm than good. Its bulletin does not mention multi-detector CT (MDCT) screening, which is the scan Clouse does now, having switched from EBCT.
“After going to some meetings and listening to some individuals,” he says, “it suddenly occurred to me that calcium represented the insult from all the risk factors that we have, whether it be cholesterol, homocystine, smoking, diabetes—95% of diabetes is self-induced. People eat themselves to death, actually.”
He adds, “Every study that has ever been done shows that if you can arrest and stabilize the process, you can live with arteriosclerosis. It’s the progression that gets people in trouble. So, you can really affect outcome, and that’s why I believe in screening for calcium.”
He may be gathering allies. A new study of more than 4,000 people reportedly shows that EBCT calcium scoring is a more accurate predictor of coronary risk than other tests.6
Clouse says he switched to MDCT because the image slices are thinner and it is more accurate. “With the helical scan now, with multi-segmented reconstruction, retrospectively gated, you can use beta blockers to slow the heartbeat down to where you can get good images…. The [radiation] dose is higher with MDCT, but considering the coronary artery disease risk, I think it’s worth it.”
He says thousands of lives might be saved if people with risk factors like high cholesterol and high blood pressure were screened for coronary calcium.
“You have a simple test, and it’s more accurate than anything we do…. It tells you if you’ve got a problem. It doesn’t tell you how bad it is, it just tells you if you ought to do something about it.”
Because insurers do not typically pay for the procedure, Clouse sees self-pay patients in an outpatient setting.
“I give them a report (including laboratory tests) and a CD, and if they were referred, I tell that doctor what I would do. You first of all have them exercise and change their diet, and maybe 20% to 30% can get down to acceptable levels. Another 30% need statin drugs. If they’ve got calcium, I ask them to come back in a year to see how it looks. Theoretically, if you stop arteriosclerosis, you may stop plaque and the calcium score may stabilize. You can see it stabilize or progress, but it depends on what the culprit is. We still don’t know what all the risk factors are. Genetics plays a role, the arterial walls play a role, and other inflammatory markers. The story isn’t tied up and ended by any means.”
But the story would have a happier progression if insurance carriers would pay for calcium scoring, Clouse says. “By the time we get to age 50, about 85% of us have significant plaque in the coronary arteries, because we all eat too much fat….The medical profession should recognize this, and the insurance companies should pay for it every 2 years for those who do have calcium.”
But Clouse says he does not expect anybody to initiate routine calcium screening for all middle-aged people. “There’s not that much money around. I just think people should become aware of it and take control of their own health.”
He recounts the statistics again, including that well over 100,000 people die annually from heart attacks in which the attack itself is the first and last symptom. “You are talking about an enormous problem, but nobody mentions that.”
COLON CANCER
According to NCI data, colon cancer kills about 60,000 people each year, men and women in roughly equal numbers. Most of those diagnosed with the disease are more than 50 years old. The overall survival rates for colon cancer are relatively high; 1-year survival is 83%, and 5-year is 63%. For early-detected cancer, the 5-year survival rate is 90%, however. But only 39% of colon cancers are diagnosed early due to low rates of screening.
 Andrew H. Dachman, MD |
Abraham H. Dachman, MD, FACR, is professor of radiology at the University of Chicago Medical School. He is also a researcher and practitioner of CT colonography, as it is preferably called now, although Dachman is comfortable calling it by its less formal name, virtual colonoscopy.
For years, virtual colonoscopy (VC) has been touted as the wave of the colon cancer screening future. Unlike the gold standard screen, optical colonoscopy, VC is noninvasive, but it does require preparation on the part of the patient to cleanse the bowels for imaging.
The big problem with VC is that, like most imaging screens, it is not being reimbursed by either private payors or Medicare. Until last year there was not even a CPT code for billing VC. The current code does not recognize screening as a reimbursable use of VC. In essence, VC can be billed as a screen only in the event of a failed instrument colonoscopy.
Dachman and others are pushing to change that. One of the promises of VC is that because it is quick and noninvasive more people can be screened, and presumably, for the same reasons, more people would comply with their doctors’ recommendations to undergo colon screening.
On March 16 of this year, Dachman appeared before a US Senate Cancer Coalition hearing. He told the panel in part:
 Figure 3. A transparent view of a CT colonography study indicating the locations of polyps with green and mass with red. Image courtesy of Andrew H. Dachman, MD. (Click the image for a larger version.) |
“I believe that gastroenterologists should work hand-in-hand with radiologists to implement a more cost-effective use of available resources. Low-risk patients should be screened with CT colonography, which is cheaper, less invasive, and easily performed with existing imaging facilities. The small fraction, typically 4%, of individuals who have significant polyps would be referred to colonoscopy for polyp removal. This practice would permit best use of limited and expensive resources by referring only high-risk patients to optical colonoscopy and permitting the rest to be cleared noninvasively.”
Dachman is also involved in a clinical trial—the National CT Colonography Trial—that pits VC in a head-to-head matchup with optical colonoscopy to see which is better at discovering potentially cancerous polyps. Participants in the trial get both screenings for free. The results of each screening will be analyzed to see which performs better.
Dachman says that gastroenterologists already admit that “they miss about 6% of 1 cm polyps in colonoscopy.” He says their miss rate might be closer to 12% based on other studies.7 “What that tells me,” he says, “is that as a patient, if I have both tests—where the virtual camera can pirouette like a ballerina and look in all the places in the sharp inside of the bends where gastroenterologists might miss lesions—then I get the best of both worlds.” If he were a patient, Dachman says, he would sign up for the ACRIN colonography trial.
“If somebody is qualified and knows how to read it, virtual colonoscopy is an accurate screening tool. The problem is that there’s no reimbursement for it, and most radiologists don’t know how to read it well. To get that training is not so easy. If there was reimbursement, more people would invest the time and money. It’s a Catch-22,” he says.
Dachman says that if or when VC is widely implemented, it might save money given the cost of optical screening and the wait many patients face to get screened.
“VC is going to give a menu of options to patients, and we’re going to find that we’ll do a better job of screening for colorectal cancer, whereas now many people who should be screened are not getting screened, because they’re afraid or ignorant or they’re not properly informed by their physicians,” he says. “There’s a whole host of reasons we’re not doing a good job as a nation.”
Ironically, Dachman says, before the CPT code for VC was adopted, he was able to screen more patients than he is now. “For several years, I was just billing it as an uninfused abdomen,” he says. Now, he adds, that is illegal. So now most of the patients he screens are participants in the ACRIN trial, who are screened using that trial’s protocol.
As for self-paying patients who may have stumbled across the procedure on their own or who talked a doctor into referring them, Dachman says he sees only about one like that every week.
One of the possibly advantageous impacts of VC, Dachman says, is that there are significant extracolonic findings, maybe on as many as 10% to 12% of screened patients.
“It’s a doubled-edged sword, because sometimes you work some of those up and you wish you never had…. On the other hand, I have a couple of patients I found renal cell cancers on.”
Dachman also foresees VC being done in combination with other CT screening, perhaps for aortic calcification.
“You see the abdominal aorta. They apply the same coronary calcification score to the coronary arteries that they apply to the large abdominal aorta where it bifurcates into the iliac arteries at the level of the umbilicus. So that’s another possible novel extracolonic finding. There are things we know and things we don’t know and things waiting to be discovered. But you certainly can’t see outside the colon in optical colonoscopy.”
Dachman says he believes VC will eventually be reimbursed and prove itself as a screening tool. He says gastroenterologists are aware of this too. “The ones who are the most vocal against it are the same ones trying to buy their own CT scanners to do it,” he says. “How can you do both? If the technique’s no good, why are you trying to buy a CT unit?”
AORTIC ANEURYSMS—CAROTIDS
Ultrasound is the modality of choice for the screening of abdominal aortic aneurysms (AAA). Ultrasound is also used to identify flow limiting stenosis in the carotid arteries.
Women are rarely afflicted with AAA; men are not so fortunate. Estimates are that about 9,000 die annually. The good news for men is that the Preventive Services Task Force earlier this year recommended that men between the ages of 65 and 75 who are current or former smokers have a one-time ultrasound scan for AAA. No recommendation was made for screening the same group of males who had never smoked.
 Edward I. Bluth, MD |
Edward I. Bluth, MD, FACR, is chairman of the radiology department at the Ochsner Clinic Foundation in New Orleans. He is also an ultrasound specialist who oversees the foundation’s AAA and carotid artery screening programs. He has trained other physicians to interpret the screens, but he also interprets many of them himself, he says. The numbers who seek AAA screening are not high, he says, maybe five to 10 patients a month.
Bluth says reimbursement for AAA screening has not caught up to the Task Force recommendation. The patients seen at Ochsner are largely self-paying. But he is hopeful that reimbursement will soon be approved. “Once that happens, we’re ready,” he says.
He calls AAA screening for the target group “tremendously” important. “The incidence of AAA in that population is 5% to 10%. The incidence of breast cancer in the female population is much, much lower.”
Bluth recommends that all men above the age of 60 get screened. “People who have hypertension, smokers, or those with first degree relatives who have had an aortic aneurysm should absolutely have screening.”
He says the message on screening is not getting out fast enough. “The insurance companies have been slow to act, and they should be acting. We should have large screening projects; we would save considerable numbers of lives.”
A recent study in the United Kingdom showed that AAA death was reduced by 42% with screening. “And surgical mortality was 6% or less after the elective surgery,” he adds. That compares to about a 38% death rate for patients undergoing emergency surgery for AAA, he says.
The AAA screen is a yes-no test, normal abdominal aorta versus abnormal. If normal, no more tests are required. If abnormal, then the patient goes on to a full diagnostic work-up to assess the size of the aneurysm and its relationship to the renal arteries, Bluth says. He says the diagnostic test can be with ultrasound, CT, or MR.
At Ochsner, patients also can be screened with ultrasound for carotid artery blockage. The Preventive Services Task Force has taken no position on carotid artery screening. Like AAA screening, patients primarily pay for it themselves.
Bluth says both the AAA and the carotid ultrasound screens are quick—about 5 minutes per scan—and inexpensive. Each procedure can be done for $50, he says. He says patients commonly pay $100 and get both tests. “People understand the value.”
 Figure 4. Positive ultrasound screening for carotid artery blockage. Image courtesy of Edward I. Bluth, MD, Ochsner Clinic Foundation. (Click the image for a larger version.) |
The carotid testing is more complicated than the screen for AAA, according to Bluth.
“What we are doing is identifying flow limiting stenosis,” Bluth says, “identifying whether it’s less or greater than 40%.”
If less, the test is negative and there are no more requirements for the patient, but if the test is positive, the patient goes on for further diagnosis. That includes grading the stenosis to determine the next step, medication or intervention, Bluth says. If stenosis is 60% or more in a symptomatic patient, Bluth recommends intervention. “If it’s more than 80% in an asymptomatic patient, everyone will intervene,” he adds.
He says it is important to distinguish whether plaque is homogeneous (stable) or heterogenous (unstable).
“Intervention based on plaque grading is a little controversial. Everyone doesn’t accept this,” Bluth says. “What we know is that heterogeneous plaque contains intraplaque hemorrhage. Plaque that contains intraplaque hemorrhage is unstable in the coronary arteries, and we strongly feel that it’s unstable in the carotid arteries as well.”
If plaque is heterogeneous, Bluth says he recommends intervention at an earlier stage “with endarterectomy, not angioplasty and stent.
“I’m worried about rupturing the plaque, which is heterogeneous and causing distal emboli,” he says. But all this, he adds, is part of the diagnostic decision-making, not part of the screening effort.
Bluth was first author on a study that determined that carotid scoring with ultrasound could be cost-effective.8
“It could be much more cost-effective if those being screened were smokers or had hypertension,” he says.
Bluth says that with both the AAA and carotid ultrasound screens there are no incidental findings because the tests focus solely on one disease or the other.
CONCLUSION
To date, no broad-based radiological screening of asymptomatic patients is being reimbursed except for breast cancer mammography. Yet, as has been seen, several screening tests for the most egregious diseases are available. Thousands, even hundreds of thousands, of lives might be saved if the screening tests were widely implemented. But for now there is a waiting game to see the results of clinical trials before the government or the private sector shoulders the burden of paying for these screens, if either sector ever does.
Richard Duszak, MD, is president of a radiological practice in Reading, Pa, West Reading Associates. He is also chairman of the ACR’s committee on coding and nomenclature.
Duszak says the ACR has worked with the American Medical Association to make sure that the CPT codes are in place for all the screening procedures. But having a CPT code available does not mean reimbursement will be forthcoming, he notes.
He says some payors now will reimburse for a CT colonography if an optical colonoscopy fails, but there have to be nonscreening indications for the conventional colonoscopy, he adds.
He says the ACR has taken a strong stance supporting screening mammography but not on the other available screens.
“Those need to be handled on a case-by-case basis,” he says. “Some are valuable and cost-effective; there are other screening services that are not necessarily cost-effective.”
Like everyone else, the ACR is waiting for more factual information about the screens, he says.
“It’s expensive technology, and unless it’s of demonstrable value to patients, we’re not going to push reimbursement,” Duszak says. “The credibility of the profession is on the line. We want to be perceived—and I think we are—as credible providers of imaging services.”
CAD for Mammography—Yes or No? |
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Even a well-accepted screening test like mammography might be improved with the addition of computer-aided detection (CAD) software to help spot cancerous breast lesions. At the Medical College of Georgia (MCG) in Augusta, the deployment of a mammography CAD system is under study now. James Rawson, MD, is Warren Professor at MCG and chairman of the radiology department. Rawson says the college is doing financial projections to determine the break-even point for purchase versus leasing a CAD system. “If you add CAD to the exams you are doing, how long would it take to pay back the equipment on the technical side? And on the professional side, what is the weight of reimbursement for interpretation with CAD?” he says. “If you bought a piece of equipment but the break-even point was 10 years out, you might not view that as a good investment.” Money is not the only decision-making factor, though. James Craft, MD, is an assistant professor interpreting mammograms at MCG. He estimates that between 35 and 70 asymptomatic women per day are screened for breast cancer. He interprets most of the examinations. He says CAD might improve the quality of the studies and the interpretations. “The CAD is a tool to help me from burning out my eyes. I’m only human. We don’t want to miss anything.” It is MCG’s intent, he says, to take mammography patients with cysts to ultrasound for follow-up diagnosis the same day. “That’s better than sending out a letter. If we can settle the matter while they’re here, that increases their peace of mind.” Craft and Rawson both say CAD systems do peg false positives and false negatives. “The computer is good but not perfect. A human has to decide what to do next,” Craft says. Both say the CAD could never be used alone for interpretation. “The CAD will raise areas of concern,” Rawson says. He also says mammograms done with CAD may allow lesions to be spotted and treated earlier. Neither doctor expects CAD to speed up the flow of patients. The technicians work at the same speed with or without CAD, Craft notes. Rawson says MCG’s decision on CAD will be made “in the next few months.” “I think we can make CAD successful for the hospital and the patients,” Rawson says. MCG is looking at more than just CAD. It is also one of 20 centers across the country involved in the study of a portable device that uses electrical current rather than x-ray to scan breasts for lesions. The device is based on evidence that electrical current passes more easily through cancerous tissue than noncancerous tissue. “It may become a screening study for breast cancer,” Craft says. But no one will know that for 2 years or so. “We can see the lights flashing, but we’re double-blinded. I’m not reading their electrical study, and they’re not reading my mammograms.” |
| —G. Wiley |
George Wiley is contributing writer for Decisions in Axis Imaging News.
References:
- Kolata G. Rapid rise and fall for body-scanning clinics. New York Times. January 23, 2005.
- ACR Statement on CT Screening Exams, Home Media Room Position Statements, September 28, 2002. Available at: www.acr.org.
- See www.acrin.org for descriptions and protocols of these and other ACRIN trials.
- Hillman BJ. The future of imaging screening: proceedings of the Fourth Annual ACR Forum. JACR. 2005;2:43-50.
- Report to the Nation. Bethesda, Md: National Cancer Institute; 2004.
- Arad Y, Goodman KJ, Roth M, Newstein D, Guerci AD. Coronary calcification, coronary disease risk factors, C-reactive protein, and atherosclerotic cardiovascular disease events: the St Francis Heart Study. JACC. 2005;46:158-165.
- Pickhardt PJ, Nugent PA, Mysliwiec PA, Choi JR, Schindler WR. Location of adenomas missed by optical colonoscopy. Ann Intern Med. 2004;141:352-359.
- Bluth EI, Sunshine JH, Lyons JB, et al. Power Doppler imaging: initial evaluation as a screening examination for carotid artery stenosis. Radiology. 2000;215:791-800.
