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In recent years, the cardiac capabilities of computed tomography, magnetic resonance imaging, and to a lesser extent positron emission tomography have rapidly advanced. This has led to contention between radiologists and cardiologists over who should perform and interpret these studies. The authors present the arguments favoring both sides and discuss strategies radiologists should pursue. Although the arguments favoring radiologists are more compelling, this may be an instance in which both sides should work together.

Purpose: To determine changes in the number of dual-energy x-ray absorptiometry (DEXA) procedures performed in the United States, as well as changes in the relative number of procedures performed by radiologists and nonradiologists., Methods: The two major Current Procedural Terminology, Fourth Edition, codes for DEXA scans were selected from the national Medicare Part B databases from 1996 through 2002 (the most recent). The total number of scans done on Medicare patients, as well as the percentages performed by radiologists and nonradiologists, were tabulated., Results: In 1996, a total of 501,505 DEXA scans were performed among all Medicare patients. Of these, 30% were performed by radiologists. In 2002, there were 2,195,548 DEXA scans performed among all Medicare patients, of which radiologists performed 45%., Conclusion: Between 1996 and 2002, the number of DEXA scans performed on all Medicare patients increased by more than fourfold. In the same population, the percentage of scans performed by radiologists increased from less than one-third to almost one-half. Consequently, radiologists are steadily gaining market share of this procedure in the Medicare population.

Training standards for radiologists and other physicians who wish to perform and interpret imaging have been developed by many medical organizations. There is considerable overlap, and some are contradictory. In this article, the authors review some of the existing standards and proposals for new ones and discuss how they might affect the credentialing of physicians in the near future.

In recent years, emergency medicine physicians have made strenuous efforts to take over responsibility for interpreting and billing for ultrasound and conventional x-ray studies performed in emergency departments. This is a battle that radiologists have largely won. The authors explore some of the history of this controversy and the reasons why radiologists still control emergency department imaging.

Purpose: To examine trends in emergency medicine physicians' participation in diagnostic ultrasound and conventional radiography from 1993 to 2001., Methods and Materials: The nationwide Medicare Part B Physician/Supplier Procedure Summary Master Files for 1993 and 1996 through 2001 were examined to determine the total number of ultrasound and conventional radiography examinations performed in emergency departments, except for ophthalmic ultrasound and supervision or interpretation claims. Ultrasound examinations were categorized as general, vascular, breast, echocardiography, and obstetrical. Conventional x-ray examinations were categorized as chest, skeletal, abdomen, and gastrointestinal fluoroscopy. The total volume and overall share of the two modalities and nine aforementioned categories were calculated for each year for radiologists, emergency medicine physicians, other nonradiologists, and multispecialty groups using the Medicare provider and location-of-service codes., Results: The total volume of ultrasound examinations performed in emergency departments increased from 134,533 in 1993 to 355,889 in 2001 (+164.5%). Emergency medicine physicians performed 760 (0.6%) of the examinations in 1993 and 1160 (0.3%) in 2001. Radiologists performed 87,377 (64.9%) in 1993 and 257,479 (72.3%) in 2001, other nonradiologists (primarily cardiologists performing echocardiography and vascular surgeons performing vascular ultrasound) performed 40,501 (30.1%) in 1993 and 76,649 (21.5%) in 2001, and multispecialty groups performed 5895 (4.4%) in 1993 and 20,601 (5.8%) in 2001. The total volume of conventional radiography examinations increased from 5,120,608 in 1993 to 8,054,771 (+57.3%) in 2001. Emergency medicine physicians performed 243,705 examinations (4.8%) in 1993 and 167,968 (2.1%) in 2001, radiologists performed 4,558,933 (89.0%) and 7,478,659 (92.8%), other nonradiologists performed 113,848 (2.2%) and 99,627 (1.2%), and multispecialty groups performed 204,122 (4.0%) and 308,517 (3.8%). The largest volume of examinations performed by radiologists and emergency medicine physicians in emergency departments in 2001 was in chest radiography, with radiologists performing 3,765,209 and emergency medicine physicians performing 98,851. The largest volume for other nonradiologists in emergency departments in 2001 was in echocardiography; they performed 53,943 of these examinations., Conclusion: Emergency medicine physicians perform a very small percentage of all ultrasound and conventional x-ray examinations performed in emergency departments, with their share decreasing over the 8-year period. The fact that the participation of emergency medicine physicians in ultrasound imaging and conventional radiography in emergency departments is limited and has been decreasing makes their claim of substantial participation highly questionable.

Purpose: This study aimed to determine the relative roles of radiologists, cardiologists, vascular surgeons, and other physicians in performing percutaneous peripheral arterial interventions and how these roles have changed over a recent 5-year period., Methods and Materials: The authors reviewed the Medicare Part B fee-for-service databases between 1997 and 2002 for the Current Procedural Terminology (4th ed.) (CPT-4) surgical procedure codes for percutaneous transluminal angioplasty (PTA) of noncardiac peripheral arteries (six codes), the transcatheter placement of noncardiac intravascular stents (two codes), and endovascular aortic stent graft placement (six codes). Using the Medicare physician specialty codes, procedure volume in each CPT-4 code was determined for radiologists, cardiologists, vascular surgeons, and other physicians. Percentage changes from 1997 to 2002 were calculated for PTA and intravascular stent placement procedures., Results: Between 1997 and 2002, the total Medicare procedure volume in the eight procedure codes relating to PTA and stent placement increased by 95%. In 2002, radiologists performed 72,657 of these procedures, cardiologists 62,901, vascular surgeons 17,895, and other physicians 19,666. Over the 5-year interval, procedure volume among radiologists increased 29%, among cardiologists by 181%, among vascular surgeons by 398%, and among other physicians by 195%. Radiologists' share in the total pool of procedures in 2002 was 42.0% (down from 63.3% in 1997), cardiologists' 36.3% (up from 25.2% in 1997), vascular surgeons' 10.3% (up from 4.0% in 1997), and other physicians' 11.4% (up from 7.5% in 1997). Trend data were not available for endovascular aortic stent graft procedures., Conclusion: Between 1997 and 2002, procedure volume in percutaneous peripheral arterial interventions grew at faster rates among cardiologists, vascular surgeons, and other physicians than it did among radiologists. As a result, radiologists' share of this market declined during the interval. However, procedure volume among radiologists continued to grow over the 5 years, and in 2002, they still had the largest share among the four physician specialty groups. Thus, despite the erosion, interventional radiologists still maintain a strong position in this rapidly growing field.

Interventional radiologists in many hospitals are involved in confrontations with cardiologists and vascular surgeons over who should be allowed to perform percutaneous noncardiac peripheral vascular interventions. There are valid reasons why radiologists should be the ones doing these procedures: first, because in any given hospital, radiologists are generally the physicians with the best training and most experience, and second, because they are generally not in a position to self-refer and will therefore be able to help keep utilization under control. If cardiologists or vascular surgeons request vascular interventional privileges at your hospital, there are steps you can take to see if they are properly qualified. If they are granted privileges, there are other steps you can take to ensure that high standards of patient care are maintained. The authors also present some discussion of how interventional radiologists can position themselves to either compete with or collaborate with the other clinical services. Throughout any confrontations that might occur, radiologists should stress that patients undergoing these procedures deserve the best possible care, which means that they should be performed by those physicians on the hospital staff who are the most knowledgeable and the least likely to commit medical errors.

Purposes: To determine the apportionment of Medicare Part B payments for noninvasive diagnostic imaging among radiologists and other specialists and to ascertain the trends in these payments over a recent 5-year period., Methods and Materials: Using the nationwide Medicare Part B databases for 1997 through 2002, all payments were calculated for physician services for noninvasive diagnostic imaging codes in the 70,000 Current Procedural Terminology, Version 4 series and those codes in the 90,000 series pertaining to echocardiography and vascular ultrasound. Imaging studies were grouped into 26 different categories depending on type and modality. The 108 Medicare physician specialty codes were used to group payments into 20 different specialist categories. The percentage shares for each specialty group in 1997 and 2002 were calculated. Percentage changes in payments between 1997 and 2002 were determined., Results: In 2002, Medicare Part B paid almost $7.7 billion for noninvasive diagnostic imaging services. Radiologists received 48.3% of these payments, and cardiologists received 22.8%. Between 1997 and 2002, overall payments to physicians for noninvasive diagnostic imaging rose by 78%. Payments to radiologists increased by 65%, while payments to cardiologists increased by 105%. Primary-care physicians received 8.3% of 2002 payments, while 10.2% went to independent diagnostic testing facilities or multispecialty groups. For the latter two entities, the specialties of the physician providers could not be determined., Conclusion: Radiologists receive only about half of all Medicare Part B reimbursements for noninvasive diagnostic imaging. Cardiologists receive almost one-quarter. Payments to cardiologists are rising more rapidly then to any other specialty group and considerably more rapidly than payments to radiologists.

The time seems to be ripe for reforms that will address the rapid growth of self-referral in diagnostic imaging by nonradiologist physicians. The authors present a possible course of action containing six elements that federal or state governments and/or payers could take that would assist them in their efforts to control this ubiquitous problem: (1) a legislative ban on self-referral for certain types of imaging, (2) mandatory accreditation and/or site inspections of all imaging facilities, (3) the limitation of imaging privileges among nonradiologists, (4) the required precertification of all self-referred imaging examinations, (5) the auditing of records of physicians who self-refer, and (6) certificate-of-need laws.

Purpose: To determine the influence of three factors involved in the angiographic assessment of balloon angioplasty-interobserver variability, operator bias, and the definition used to determine success-on the primary (technical) results of angioplasty in the peripheral arteries., Materials and Methods: Percent stenosis in 107 lesions in lower-extremity arteries was graded by three independent, experienced vascular radiologists ("observers") before and after balloon angioplasty and their estimates were compared with the initial interpretations reported by the physician performing the procedure ("operator") and an automated quantitative computer analysis. Observer variability was measured with use of intraclass correlation coefficients and SD. Differences among the operator, observers, and the computer were analyzed with use of the Wilcoxon signed-rank test and analysis of variance. For each evaluator, the results in this series of lesions were interpreted with three different definitions of success., Results: Estimation of residual stenosis varied by an average range of 22.76% with an average SD of 8.99. The intraclass correlation coefficients averaged 0.59 for residual stenosis after angioplasty for the three observers but decreased to 0.36 when the operator was included as the fourth evaluator. There was good to very good agreement among the three independent observers and the computer, but poor correlation with the operator (P

There is considerable emphasis currently placed on the need to reduce medical errors and improve patients' safety. Because diagnostic imaging is such an important part of the workup of most medical conditions, one way to help achieve this goal is to insist that imaging facilities and the imaging examinations they produce meet high standards of quality. Published studies have shown that radiology facilities and radiologists consistently generate higher quality images than most other medical specialties. Radiologists should bring this evidence to the attention of payers and medical policy makers in their areas who are responsible for decisions affecting patients' safety.

Purpose: To ascertain changes in the utilization rates of diagnostic ultrasound among radiologists, cardiologists, and other physicians in recent years., Methods and Materials: The nationwide Medicare Part B databases for 1993 and 2001 were searched in all ultrasound Current Procedural Terminology 4 codes, except for ophthalmic ultrasound and supervision and interpretation codes. Ultrasound examinations were categorized as general, vascular, breast, obstetric (very low in the Medicare population), and echocardiography. Using the Medicare physician specialty codes, utilization rates per thousand Medicare beneficiaries per year were calculated for radiologists, cardiologists, and other physicians for all codes in the five aforementioned categories., Results: Radiologists performed 24% of all ultrasound examinations in 2001. The overall utilization rate of ultrasound examinations among radiologists increased from 132.9 per thousand Medicare beneficiaries in 1993 to 166.3 in 2001, a 25% increase. Among cardiologists, the rate increased from 190.3 in 1993 to 356.1 in 2001, an 87% increase. The vast bulk of these examinations were echocardiograms, but cardiologists also had some involvement in vascular ultrasound. Among other physicians, the rate increased from 116.9 in 1993 to 167.0 in 2001, a 43% increase. The areas of greatest involvement by these other physicians were echocardiography, vascular ultrasound, and general ultrasound. Of the five ultrasound categories, echocardiography had by far the highest volume., Conclusion: Nonradiologist physicians utilize ultrasound at much higher rates than radiologists, primarily reflecting the influence of echocardiography. Between 1993 and 2001, the ultrasound utilization rate grew over 3 times as rapidly among cardiologists as among radiologists; the rate among other physicians grew almost twice as rapidly as it did among radiologists. This raises the concern that self-referral may be leading to higher utilization and costs.

Previous publications have demonstrated that in side-by-side testing, radiologists clearly outperform nonradiologist physicians at interpreting plain radiographs. Other articles, mostly in the nonradiologic literature, have shown that in actual practice settings, nonradiologist physicians make frequent errors in image interpretation. On the other hand, several other studies have concluded that such errors are infrequent and generally do not affect patient outcomes. However, most of the latter studies have had methodologic flaws. Radiologists need to be aware of the evidence that exists in the medical literature on errors made by nonradiologists in image interpretation and to bring it to the attention of hospital authorities or medical policy-making groups that are charged with improving patient safety.

The overutilization of noninvasive diagnostic imaging (NDI) is a complex problem with many other aspects aside from self-referral. This article discusses (1) other causes of overutilization, (2) the rationales used by nonradiologist physicians to justify self-referring their patients for NDI, (3) the extent of self-referral by radiologists (called "autoreferral" by some), and (4) steps that could be taken to curb the overutilization of NDI in the United States. It is important for radiologists to be familiar with these issues and to support efforts to control overutilization.

A recent report by the Medicare Payment Advisory Commission to Congress indicated that the utilization of diagnostic imaging is growing more rapidly than that of any other type of physician service. This has engendered concern among those who pay for health care. In this article, the authors review the role of self-referral in driving up imaging utilization. A number of studies of the self-referral factor in imaging have been conducted over the past three decades. These have consistently shown that when nonradiologist physicians operate their own imaging equipment and have the opportunity to self-refer, their utilization is substantially higher than among other physicians who refer their patients to radiologists. It has also been shown that the vast bulk of the recent increases in imaging utilization are attributable to nonradiologists who self-refer. The authors estimate that the cost to the American health care system of unnecessary imaging resulting from self-referral by nonradiologists is $16 billion per year.

Turf wars over medical imaging have become ubiquitous. At many centers, radiologists already have lost access to important technologies and their applications. A combination of decreasing revenues in other specialties and a growing attachment to imaging further threatens radiologists' practices in the future. This is the first of an extended series of articles that will address the phenomenon of self-referral--its motivations, extent, and the threats it poses to radiologists. Each article will focus on a specific aspect and provide advice on how radiologists can deal with self-referral in their locales.

Purpose: To compare nationwide trends in noninvasive diagnostic imaging (NDI) practice patterns of radiologists and of nonradiologists among the Medicare population during the 6 years from 1993 to 1999., Materials and Methods: Medicare Part B claims files from 1993, 1996, and 1999 were analyzed for all procedure codes related to NDI. NDI codes were classified into 22 diagnostic categories within seven imaging modality groups. For each NDI code, physicians performing the services were classified as radiologists or nonradiologists by using the provider specialty code designated in claims in the files. The data were analyzed to determine the overall utilization rates and relative value unit (RVU) rate changes between 1993 and 1999 among radiologists and nonradiologists., Results: In 1993, the overall NDI utilization rate per 100,000 Medicare fee-for-service beneficiaries was 215,652 for radiologists and 79,942 for nonradiologists. In 1999, the rate was 207,270 for radiologists and 100,059 for nonradiologists, which is a 3.9% decrease among radiologists and a 25.2% increase among nonradiologists. In the 6-year interval from 1993 to 1999, the overall RVU rate increased 6.9% among radiologists and 32.4% among nonradiologists. The percentage of NDI performed by radiologists decreased from 73.0% in 1993 to 67.4% in 1999., Conclusion: Overall, the utilization rate of advanced, high-technology imaging is increasing among both radiologists and nonradiologists. However, it is increasing at a considerably more rapid rate among nonradiologists.

Purpose: To determine current utilization rates and recent nationwide trends for noninvasive diagnostic imaging (NDI) among the Medicare population., Materials and Methods: Medicare Part B claims data files from 1993, 1996, and 1999 were analyzed for all procedure codes related to NDI. NDI codes were grouped into 22 imaging categories, as well as seven imaging modality groups. The data were analyzed to determine the overall nationwide utilization and relative value unit (RVU) volume and rates and changes in utilization rates and RVU rates between 1993 and 1999 for the Medicare fee-for-service population, which included approximately 33 million enrollees per year., Results: The overall utilization rate for all NDI in 1999 was 324,974 examinations per 100,000 enrollees. Conventional radiography was the most utilized imaging technology (55.5%), followed by ultrasonography (US) (20.5%), computed tomography (CT) (8.8%), mammography (6.0%), nuclear imaging (5.2%), magnetic resonance (MR) imaging (2.6%), and bone densitometry (1.5%) (percentages do not add up to 100% due to rounding). In the 6-year interval from 1993 to 1999, the rate of NDI utilization increased 3.8%. The utilization rate for conventional radiography decreased 13.7%, while that of all other modalities increased a combined total of 39.1%. During this 6-year period, RVU rates per 100,000 increased 14.6%, with RVUs for MR imaging increasing 76.6%; those for nuclear imaging, 38.7%; those for CT, 28.3%; and those for US, 24.2%., Conclusion: A 3.8% increase in the rate of NDI utilization occurred during the 6-year period between 1993 and 1999. A considerably larger increase in RVU rates (14.6%) occurred during the same time period.

Purpose: To evaluate spinal injection procedures for trends in volume, reimbursement, and physician specialty participation., Materials and Methods: By using the 1993, 1996, 1998, and 1999 Medicare Part B claims database, we studied Current Procedural Terminology revision 4 codes used for percutaneous spinal injection procedures, including cervical and lumbar discography, disk aspiration and/or injection, facet and/or perifacet joint injection, and epidural steroid injection. For each of these procedures, volume, reimbursement, and physician specialty participation (categorized as radiology, anesthesiology, surgery, physiatry, and other specialties) for each year were recorded., Results: Despite an overall increase in spinal injection procedure volume and reimbursement from 1993 to 1999, nonradiologists performed most of these procedures. Epidural steroid and facet joint injections had the highest volume and reimbursement during this time period and were performed almost exclusively by nonradiologists (predominantly anesthesiologists). Radiologists performed more discography procedures than did other specialists in 1993, but participation decreased each year, while anesthesiologist participation increased; as of 1999, anesthesiologists performed more discography procedures than did radiologists. Although radiologists performed more disk aspiration procedures than did other specialists, procedure volume remained low during the period studied., Conclusion: Spinal injection volume and reimbursement have increased substantially in the Medicare population from 1993 to 1999. During this interval, radiologist participation has decreased. Nonradiologists perform most spinal injection procedures.

Objective: We examined Medicare and fee-for-service data sets to understand better the utilization of MR imaging for imaging the pelvis, abdomen, and chest relative to its use in imaging for other body parts and to the utilization of CT., Materials and Methods: CT and MR imaging procedure volumes for pelvis, abdomen, chest, and total were extracted from the 1993, 1996, and 1999 Health Care Financing Administration Physician/Supplier Procedure Summary Master Files, based on CPT-4 codes. We also analyzed a fee-for-service health insurance database for January 1998 through July 1999 from a single northeastern state, which included provider location (rural, suburban, or urban) and type (teaching or nonteaching site)., Results: The greatest 3-year Medicare increase was for abdominal MR imaging, from 1996 to 1999 (101% increase). However, pelvic, abdominal, and chest MR imaging together remained less than 5% of total MR imaging. Abdominal MR imaging increased more than did total MR imaging in all 10 Health Care Financing Administration regions. In the fee-for-service database, the relative procedure volume of abdominal MR imaging varied approximately fivefold from rural to urban provider locations, and approximately double from nonteaching to teaching hospitals., Conclusion: Although far more abdominal CT than abdominal MR imaging is performed, the rate of abdominal MR imaging utilization has increased more rapidly since 1993. The relative procedure volume of abdominal MR imaging varied more than fivefold from rural to urban provider locations and double from nonteaching to teaching hospitals.

Purpose: To determine the trends in utilization of non-neurologic (ie, body) magnetic resonance (MR) imaging and of MR angiographic examinations performed from 1993 to 1998, the trends in non-radiologist participation in MR imaging, and the relative reimbursements for these examinations compared with those for all other noninvasive imaging studies performed in 1998., Materials and Methods: By using the 1993, 1996, and 1998 nationwide Medicare Part B databases, utilization rates per 100,000 Medicare beneficiaries and physician reimbursements were determined for seven MR angiography and 14 body MR imaging CPT-4 (Current Procedural Terminology, version 4) codes. Medicare specialty codes were used to categorize physicians as radiologists or non-radiologists., Results: The utilization rate per 100,000 Medicare beneficiaries for all 21 MR angiography and body MR imaging codes increased from 649 in 1993 to 1,253 in 1996 and to 1,876 in 1998--a 189% increase. These rates represented 0.55% of the total noninvasive imaging volume in 1998 and 2.8% of physician reimbursements. Musculoskeletal MR imaging utilization increased 142% from 1993 to 1998 compared with a 58% increase in the utilization of other body MR imaging studies. Non-radiologist participation in musculoskeletal MR imaging increased from 2.9% in 1993 to 3.6% in 1996 and to 5.6% in 1998., Conclusion: MR angiography and body MR imaging utilization rates increased substantially from 1993 to 1998. However, these studies still account for a minor fraction of all noninvasive imaging examinations performed and fees reimbursed. MR angiography and musculoskeletal MR imaging utilization has increased rapidly. Non-radiologist participation in musculoskeletal MR imaging is increasing.

Objective: Our research was conducted to ascertain the importance of noninvasive cardiovascular imaging to the practice of radiology and to determine what percentages of noninvasive cardiovascular imaging are performed by radiologists and by other types of physicians., Materials and Methods: Using the national 1998 Medicare Part B database, we reviewed all 460 procedure codes pertaining to noninvasive diagnostic imaging and identified 65 that were specifically related to the cardiovascular system. These 65 codes were grouped in five categories: cardiac MR imaging, MR angiography, cardiovascular nuclear medicine, echocardiography, and vascular sonography. For each code and category, we determined the nationwide examination volume, the utilization rate per 1,000 Medicare fee-for-service enrollees, Part B physician reimbursements, and the percentages of examinations performed by radiologists, cardiologists, surgeons, and other physicians., Results: During 1998, 19,244,001 noninvasive cardiovascular imaging studies were performed on Medicare enrollees, which accounted for 17.7% of all Medicare diagnostic imaging studies carried out that year and 33.6% of all Part B imaging-related reimbursements paid. The utilization rate for noninvasive cardiovascular imaging was 603 per 1,000 Medicare enrollees per year. Echocardiography alone accounted for 63.4% of these examinations. Radiologists conducted 16.7% of all noninvasive cardiovascular imaging, whereas cardiologists conducted 61.5%, surgeons 4.8%, and other physicians 16.9% of the examinations. The strong role of cardiologists was largely attributable to their dominance in echocardiography. Radiologists had a substantial role in all categories except echocardiography., Conclusion: Noninvasive cardiovascular imaging represents an important component of the practice of radiology. Radiologists have substantial participation in all aspects of the field with the exception of echocardiography.

Purpose: To evaluate cardiac nuclear medicine practice patterns in different physician specialty groups to better understand a recent rapid increase in utilization of radionuclide myocardial perfusion imaging (MPI) and certain supplementary examinations., Materials and Methods: National Medicare Part B databases from 1996 and 1998 were used to evaluate utilization of four primary procedure codes for radionuclide MPI and two supplementary codes (add-on left ventricular wall motion or left ventricular ejection fraction). Utilization rates were calculated for cardiologists, radiologists, and other physicians. Other cardiac imaging for which radionuclide imaging might be substituted was similarly studied., Results: Overall utilization rate of radionuclide MPI per 100,000 Medicare beneficiaries increased 19.1%, from 4,046 in 1996 to 4,820 in 1998 (P <.001). However, for cardiologists the rate increased from 1,771 to 2,413 (36.3%), whereas for radiologists it increased from 1,958 to 2,031 (3.7%) (P <.001 for both changes). Overall utilization rate of add-on codes increased 264% from 1,006 to 3,657 (P <.001). By 1998, the ratio of these add-on examinations to primary MPI was 0.94 among cardiologists compared with 0.53 among radiologists (relative risk, 1.77; 95% CI: 1.76, 1.78). Cardiologist-performed stress echocardiography and cardiac catheterization and coronary angiography increased by 24.2% and 8.7%, respectively., Conclusion: Growth in utilization of radionuclide MPI between 1996 and 1998 was almost 10 times higher among cardiologists than radiologists. Utilization of the two add-on codes increased even more dramatically. The greater use of MPI is not a substitute for other cardiac imaging.

Background and Purpose: Powerful tools, including CT and MR imaging, have revolutionized neuroimaging. These are routinely used, but the extent and variation of use has not been studied. Our purposes were to determine the use rates of MR imaging and CT (of spine, brain, or head and neck), myelography, conventional angiography, and MR angiography in diagnosing neurologic disorders; to study trends in use; and to determine regional variations in use., Methods: We used the National Part B Medicare Database for 1993 and 1998 to compare rates of use for these procedures in 10 geographic regions., Results: In 1993 and 1998, respectively, 13,897 and 19,431 (39.8% increase) neuroimaging procedures were performed per 100,000 Medicare beneficiaries nationwide. Use of brain or head and neck CT (30.4%) and MR imaging (43.6%), spinal CT (3.5%) and MR imaging (83.0%), myelography (56.6%), and conventional angiography (24.3%) increased in 1998 versus 1993. Increases in MR angiography were not assessed, because this procedure was not reimbursable in 1993. Regional use of brain or head and neck and spinal CT and MR studies varied considerably; ratios of highest and lowest rates were 1.38-1.56. Use of MR angiography, myelography, and conventional angiography varied three- to fourfold., Conclusion: Use of MR and CT studies of the brain or head and neck and of the spine increased considerably in the Medicare population between 1993 and 1998. Use of conventional invasive procedures such as myelography and angiography increased strikingly, contrary to the expected decline. Regional use varied substantially.

Purpose: To determine the extent to which emergency medicine physicians have assumed responsibility for performing and interpreting ultrasonographic (US) studies in emergency departments (EDs) in the United States., Materials and Methods: The national 1997 Medicare Part B database was searched by using standard US procedure codes, location codes, and physician specialty codes. The authors determined how many US studies were performed in EDs and what percentage of those studies were performed by emergency medicine physicians, radiologists, or other physicians., Results: During 1997, 234,820 ED US studies within nine major examination categories were performed in Medicare patients nationwide. Emergency medicine physicians performed 1,551 (0.7%) of these studies. When echocardiographic examinations were excluded, emergency medicine physicians performed 458 (0.2%) of the remaining total of 196,158 studies., Conclusion: Although emergency medicine physicians have claimed to be actively involved in ED US on a broad scale, the data reveal that their involvement in 1997 was minimal. This raises doubt as to whether they can properly train their residents to perform US or maintain their own competence at acceptable levels.

This article summarizes the primary recommendations of the Agency for Health Care Quality's recently published Smoking Cessation Clinical Practice Guidelines. Specific recommendations are outlined to assist physicians in treating patients who smoke to end their use of tobacco.

Objective: The purpose of this study was to evaluate the relationship between clinical and academic productivity over a 2-year period in a university hospital radiology department., Materials and Methods: Clinical productivity, as determined by the number of total professional relative value units generated, was compared with academic productivity, which was determined by the number of published peer-reviewed articles, published non-peer-reviewed articles, published abstracts, and presentations delivered by each full-time clinical faculty member. The relationships of age, academic rank, administrative position, and division within the department were also assessed for their effect on relative value units and academic productivity., Results: We found a significant inverse relationship between relative value units and the number of published peer-reviewed articles, published abstracts, and presentations. Age, academic rank, and administrative responsibilities had no effect on the number of relative value units. Faculty in the neuroradiology and cardiovascular-interventional radiology divisions generated more relative value units than did other faculty members., Conclusion: Faculty members with higher levels of clinical productivity showed significantly lower levels of academic productivity. This finding is consistent with the idea that increases in the clinical workload may diminish research output.

Purpose: Vascular surgeons have become concerned recently about perceived threats to their practices posed by the growth of interventional radiology. The authors studied nationwide 1996 Medicare Part B procedure data to determine the seriousness of these threats., Materials and Methods: The national Health Care Financing Administration (HCFA) Physician/Supplier Procedure Summary Master File for 1996 was searched. Two hundred thirteen distinct Current Procedural Terminology (CPT-4) codes were identified for therapeutic surgical and percutaneous interventional procedures performed to treat noncardiac vascular diseases. For each code, determination was made of total volume, specialty of the physician providers, and Medicare Part B reimbursement dollars paid to the providers as professional fees. In view of the conflicts among various specialties over peripheral vascular interventions, the authors also determined the percentages of these procedures performed by radiologists, surgeons, cardiologists, and other physicians., Results: A total of 759,548 noncardiac therapeutic vascular procedures (operations or percutaneous interventions) were performed during 1996 in patients receiving Medicare benefits. Radiologists performed 135,103 (17.8%) of these procedures but received only 10.4% of professional reimbursements. By contrast, surgeons performed 510,871 (67.3%) procedures, but received 78.0% of professional reimbursements. Cardiologists performed 4.7% of procedures and other specialists performed the remaining 10.3%. Radiologists performed 75.5% of percutaneous transluminal angioplasties, the majority of thrombolysis procedures, stent placements, and portal decompression procedures, and approximately half of inferior vena cava interruptions. Cardiologists performed 12.6% of percutaneous transluminal angioplasties, surgeons performed 6.3%, and other specialists performed 5.6%., Conclusions: In terms of overall physician workload and professional reimbursements paid for invasive treatment of all types of noncardiac vascular disease, surgeons predominate and do not appear to be seriously threatened by interventional radiologists. Radiologists perform three-fourths of noncardiac percutaneous transluminal angioplasties and a majority of other percutaneous interventional therapies for vascular disease, but some inroads have been made by cardiologists and surgeons, particularly the former.

Purpose: To compare results of helical computed tomographic (CT) angiography with real-time interactive volume rendering (VR) to CT angiography with maximum intensity projection (MIP) for the detection of renal artery stenosis., Materials and Methods: Twenty-five patients underwent both conventional and CT angiography of the renal arteries. Images were blindly reviewed after rendering with MIP and VR algorithms. MIP images were viewed in conjunction with axial CT images; VR models were evaluated in real time at the workstation without CT images. Findings in 50 main and 11 accessory renal arteries were categorized as normal or by degree of stenosis., Results: All arteries depicted on conventional angiograms were visualized on MIP and VR images. Receiver operating characteristic (ROC) analysis for MIP and VIR images demonstrated excellent discrimination for the diagnosis of stenosis of at least 50% (area under the ROC curve, 0.96-0.99). Although sensitivity was not significantly different for VR and MIP (89% vs 94%, P > .1), specificity was greater with VR (99% vs 87%, P = .008 to .08). Stenosis of at least 50% was overestimated with CT angiography in four accessory renal arteries, but three accessory renal arteries not depicted at conventional angiography were depicted at CT angiography., Conclusion: In the evaluation of renal artery stenosis, CT angiography with VR is faster and more accurate than CT angiography with MIP. Accessory arteries not depicted with conventional angiography were depicted with both CT angiographic algorithms.

Rationale and Objectives: The purpose of this study was to compare color Doppler ultrasound (US), computed tomographic (CT) angiography, and magnetic resonance (MR) angiography for the evaluation of accessory renal arteries and proximal branches of the main renal artery., Materials and Methods: Fifty-six subjects who had undergone conventional arteriography of the renal arteries participated in a prospective comparison of Doppler US (45 patients), CT angiography (52 patients), and nonenhanced MR angiography (28 patients). Conventional arteriography depicted 28 accessory renal arteries and 21 proximal branches of the main renal artery within 2 cm of the aorta., Results: US depicted five of 24 accessory renal arteries seen at arteriography but no proximal arterial branches. CT angiography depicted 24 of 26 accessory renal arteries and 13 of 17 proximal arterial branches, as well as 15 additional accessory renal arteries not seen at conventional arteriography. MR demonstrated 11 of 15 accessory arteries, as well as four additional accessory arteries not seen at conventional arteriography. MR did not depict any of nine proximal arterial branches seen at conventional arteriography., Conclusion: When compared with US or nonenhanced MR angiography, CT is the preferred method for evaluation of accessory renal arteries and proximal branches of the renal artery.

Objective: We assessed the relative roles of radiologists and nonradiologists in performing chest and skeletal radiography and nonobstetric abdominal and pelvic sonography., Materials and Methods: Information was extracted from the 1993 Medicare file on procedure volume for 65 imaging procedures. Claims were categorized by the specialty of the physician and the location (office or hospital) where the service was performed., Results: In hospitals, radiologists performed virtually all chest and skeletal radiography and nonobstetric abdominal and pelvic sonography. In nonhospital settings such as offices or imaging centers, nonradiologists performed approximately two thirds of the chest and spinal radiography and nonobstetric abdominal and pelvic sonography and larger percentages (78-86%) of the pelvic, hip, lower extremity, and upper extremity radiography., Conclusion: Although radiologists perform virtually all chest and skeletal radiographs and abdominal and pelvic sonograms obtained in hospitals, they perform a distinct minority of these procedures in nonhospital settings. The data we present have certain implications for the amount of training nonradiologists receive in diagnostic imaging.

Objective: We wished to determine the extent to which MR imaging contributes to the overall costs of imaging in the United States and to compare MR imaging costs with other imaging techniques., Materials and Methods: All 23 current procedural terminology, version 4 (CPT-4) codes for MR imaging were extracted from the national 1993 Part B Medicare annual data reimbursement file. For each code, we calculated total Medicare physician reimbursements. Aggregate reimbursement for all MR imaging was compared with aggregate reimbursement for all 659 imaging-related current procedural terminology, version 4 codes and also with comparable figures for echocardiography and other categories of cardiovascular imaging., Results: Within the 23 MR imaging codes, 1,449,911 examinations were performed on Medicare patients in 1993, for which physicians were reimbursed $370 million. Medicare reimbursement of physicians for all 659 imaging-related procedures was $5.3 billion. Thus, MR imaging accounted for only 7% of all imaging costs. By comparison, a group of just 10 imaging codes, which are primarily cardiovascular in nature, accounted for $1.67 billion, or 32% of the entire Part B costs for imaging. Reimbursements for echocardiography alone are more than twice those for MR imaging., Conclusion: From the national perspective, MR imaging does not appear to warrant its reputation as a costly procedure. The costs of echocardiography and other imaging related to the cardiovascular system are considerably higher.

Purpose: To determine the level of participation of nonradiologists in computed tomography (CT) and magnetic resonance (MR) imaging of the brain, head and neck, and spine at hospitals and at private offices and imaging centers in the United States., Materials and Methods: The 1993 Part B Medicare Annual Database was used to determine the number of procedures performed by radiologists and nonradiologists at hospitals and at private offices or imaging centers. The fourth edition of the Physicians' Current Procedural Terminology was used to classify procedures., Results: Of the 3,883,391 neurologic CT and MR imaging studies billed to Medicare in 1993, 3,148,088 (81%) were obtained in a hospital setting; only 58,005 (2%) of these studies were interpreted by nonradiologists. Of the 735,303 imaging studies (19%) obtained at a private office or imaging center, only 63,115 (9%) studies were interpreted by nonradiologists. Overall, nonradiologists performed only 121,120 (3%) of the neuroimaging examinations billed to Medicare nationwide in 1993., Conclusion: The level of participation of nonradiologists in the interpretation of results from neurologic CT and MR imaging billed to Medicare is minimal.