The changing roles of radiologists, cardiologists, and vascular surgeons in percutaneous peripheral arterial interventions during a recent five-year interval.

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.

Do emergency medicine physicians perform ultrasound and conventional radiography in the emergency department? Recent trends from 1993 to 2001.

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.

Diagnosing breast lesions with contrast-enhanced 3-dimensional power Doppler imaging.

OBJECTIVE: To compare mammography with contrast-enhanced 2- and 3-dimensional power Doppler imaging for the diagnosis of breast cancer. METHODS: Fifty-five patients, who underwent breast biopsies with histopathologic assessment, participated in a study of mammography and contrast-enhanced sonography. Levovist (Berlex Laboratories, Montville, NJ) and Optison (Mallinckrodt, St Louis, MO) were administrated to 22 and 33 patients, respectively. Precontrast and postcontrast 2-dimensional power Doppler data of the lesion were obtained with an HDI 3000 system (Philips Medical Systems, Bothell, WA), and 3-dimensional data were acquired with an LIS 6000A system (Life Imaging Systems Inc, London, Ontario, Canada). Two independent and blinded readers assessed diagnosis. Receiver operating characteristic curves were computed individually and in combination for mammography and 2- and 3-dimensional sonography (before and after contrast). Histopathologic and imaging parameters were compared by Mann-Whitney statistics. RESULTS: Mammographic findings were available for 50 patients, biopsy for 54, and 2- and 3-dimensional sonographic images for 53 and 52, respectively. Of the 50 patients who had all 4 measures, 15 (30%) had malignancies. The areas under the receiver operating characteristic curve for the diagnosis of breast cancer were 0.51 for 2-dimensional contrast-enhanced imaging, 0.60 for 3-dimensional power Doppler imaging, and 0.76 for 3-dimensional contrast-enhanced imaging (P < .01). Mammography produced an area of 0.86, which increased when combined with 3-dimensional contrast-enhanced imaging to 0.90 and with all sonographic modalities to 0.96 (P < .001). The histopathologic diagnosis of benign or malignant correlated with the presence or absence of anastomoses and with the degree of vascularity assessed with contrast-enhanced 3-dimensional power Doppler imaging (P = .007 and .02). CONCLUSIONS: Contrast-enhanced 3-dimensional power Doppler imaging increases the ability to diagnose breast cancer relative to conventional 2- and 3-dimensional sonographic imaging.

Comparative increases in utilization rates of ultrasound examinations among radiologists, cardiologists, and other physicians from 1993 to 2001.

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.

Who gets paid for diagnostic imaging, and how much?

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.

Endovascular interventional neuroradiologic procedures: who is performing them, how often, and where? A survey of academic and nonacademic radiology practices.

BACKGROUND AND PURPOSE: In this report, the authors assess practice patterns at both academic and nonacademic centers regarding the treatment of aneurysms with Guglielmi detachable coils (GDCs), thrombolysis of the carotid-vertebral arteries, and stent placement with angioplasty of the carotid arteries. METHODS: A neurovascular radiology survey was sent to 102 directors of neuroradiology fellowship programs in the United States and Canada ("academic centers"). The survey was also sent to senior members of the American Society of Neuroradiology (three per state) who were not affiliated with fellowship programs ("nonacademic centers"). RESULTS: Fifty-seven surveys from academic practices and 70 surveys from nonacademic practices were returned. A total of 4361 procedures (2283 GDC; 949 thrombolysis; 1129 stent placement) were performed; 84% were performed at academic centers and 16% at nonacademic centers. Ninety percent of GDC, 71% of thrombolysis, and 82% of stent placement procedures were performed at academic centers. Seven academic and three nonacademic centers performed 48% of all GDC procedures; eight academic and four nonacademic centers performed 45% of all thrombolysis procedures; eight academic centers performed 50% of all stent placement procedures. A total of 544/4361 (12%) procedures were performed by nonradiologists. At academic centers, 14% of procedures were performed by nonradiologists; participation by nonradiologists was greatest for carotid stent placement (24% of procedures). At nonacademic centers, only 5% of procedures were performed by nonradiologists. CONCLUSION: According to this survey, most endovascular interventional neuroradiologic procedures are performed at academic centers; given the survey population, this study likely identifies the lower limit of participation by nonradiologists (12%). Performance of these procedures is concentrated in relatively few centers, and these data raise questions about the overall use of intraarterial thrombolytic therapy for acute infarction.

Practice patterns of radiologists and nonradiologists in utilization of noninvasive diagnostic imaging among the Medicare population 1993-1999.

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.

How often do neuroradiologists perform sonography of the carotid arteries? A survey of academic and nonacademic radiology practices, with implications for fellowship training.

BACKGROUND AND PURPOSE: Debate in the neuroradiology community surrounds the amount of formal training in sonography of the carotid arteries that should be provided to fellows. This study was designed to assess current practice patterns at both academic and nonacademic practices regarding the performance of carotid sonography. METHODS: A neurovascular radiology survey was sent to all 102 program directors of neuroradiology fellowships in the United States and Canada (academic practices). The survey was also sent to 146 randomly selected senior members of the ASNR (three per state, except one each for Alaska and Vermont) who were not affiliated with fellowship programs (nonacademic practices). RESULTS: Fifty-seven surveys from academic practices and 70 surveys from nonacademic practices were returned. Radiologists at academic practices performed approximately 42% of studies (general radiologists or sonography specialists, 36%; neuroradiologists, 5%; cardiovascular radiologists, 1%). Nonradiologists performed approximately 58% of studies (vascular surgeons, 47%; neurologists, 10%; cardiologists, 1%; neurosurgeons, <1%). Neuroradiologists performed carotid sonography at 11% (6/57) of academic practices. On average, radiologists at nonacademic practices performed approximately 62% of studies (general radiologists or sonography specialists, 38%; neuroradiologists, 15%; cardiovascular radiologists, 9%). Nonradiologists performed approximately 38% of studies (vascular surgeons, 25%; neurologists, 6%; cardiologists or internists, 6%). Neuroradiologists performed carotid sonography at 53% (37/70) of nonacademic practices. CONCLUSION: At most academic practices, neuroradiologists do not perform sonography of the carotid arteries. This may explain the reluctance of some fellowships to provide formal training in this technique. In contrast, although neuroradiologists perform carotid sonography at a majority of the nonacademic practices, the percentage of studies that they perform is small; moreover, neuroradiologists perform far fewer studies than do general radiologists or sonography specialists.

Nationwide trends in rates of utilization of noninvasive diagnostic imaging among the Medicare population between 1993 and 1999.

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.