Recent trends in utilization of cardiovascular imaging: how important are they for radiology?

To determine (a) the role cardiovascular imaging (CVI) plays within the spectrum of noninvasive diagnostic imaging (NDI), (b) the role radiologists play in CVI, and (c) recent trends in CVI workload among radiologists and cardiologists.

The national Medicare Part B databases for the years 1993 and 2002 were used to identify all CPT-4 codes pertaining to NDI. Those codes relating specifically to noninvasive CVI were grouped together in seven categories. The 2002 Medicare total professional component relative value units (RVUs) were then used to determine RVU rates per 1,000 Medicare beneficiaries as a measure of physician work for each code. The percentage of all NDI RVUs accruing to CVI in 2002 were calculated. Also calculated were the 9-year changes in RVU rates for each of the seven CVI categories, and the changes in those rates among radiologists and cardiologists.

CVI represented 29% of all Medicare NDI work in 2002. Between 1993 and 2002, the RVU rate for all CVI rose by 75%, compared with 34% for all non-cardiovascular imaging. Over the same years, the CVI RVU rates among cardiologists grew by 110%, compared with 50% among radiologists. In 2002, cardiologists performed 448 RVUs per 1,000 in CVI, (mostly in echocardiography and cardiac nuclear imaging) whereas radiologists performed 162. The most rapid growth among the major CVI categories was in cardiovascular nuclear imaging performed by cardiologists; this grew 452% between 1993 and 2002. Radiologists predominate in vascular US and cardiovascular CT and MRI.

CVI represents a large and important component of total diagnostic imaging services and is growing more rapidly than other types of imaging. Cardiologists dominate in CVI RVU rates and their utilization is growing more rapidly than that of radiologists'. However, radiologists predominate in vascular US and cardiovascular CT and MRI. SUMMARY SENTENCE: Cardiovascular imaging represents almost one-third of total noninvasive diagnostic imaging services and is growing more rapidly than other types of imaging; the authors explore the relative roles of radiologists and cardiologists in this field.