Vascular Imaging: Crossing Body Territories and Modalities

Imaging has become so engrained and valuable to the practice of medicine that sub-specialization has become necessary for radiology practices to manage the tremendous body of knowledge. This concentration has allowed us to practice diagnostic radiology at a high level to meet the needs of the many medical and surgical specialties. Clinical practices have shifted dramatically from utilizing imaging not only for surveillance and initial diagnosis, but also for surgical planning and long-term management of disease, which also requires greater understanding of the specific therapies in each field. Several medical and surgical specialties now rely on noninvasive vascular imaging to manage disease and for preoperative planning and postoperative observation.

Although the current silos of subspecialization have been largely beneficial for radiology, some distinct areas of imaging cover the radiological spectrum and do not conform to our present subspecialty definitions. Vascular imaging is one such discipline, which has become somewhat orphaned because of its pervasive nature and tendency to cross body territories and imaging modalities.

Clinical features of diseases with vascular etiologies frequently overlap with non-vascular diseases. For example, multiple diseases may present with post-prandial abdominal pain—though only a small fraction may end up benefiting from a course of steroids for vasculitis. A clinician’s preliminary diagnosis may be mesenteric ischemia, but the final judgment determined by MRI/MR angiography may be pancreatic cancer, or vice versa. An ulcerated plaque with a dangling thrombus may appear on a thoracic CT angiogram on one examination but disappear on the next—coinciding with a stroke, a bout of ischemic colitis, or a pulseless extremity. Rheumatologists, cardiologists, and surgeons do not terminate their attention to patients at the end of a body territory, though radiologists have largely broken down along territorial lines to improve our efficiency.

As our specialty becomes increasingly subspecialized, clinical diagnosis has become progressively distributed among a larger number of physicians. This structural change has created a certain peril of failing to “connect the dots” and fading expertise for disciplines that “just don’t fit” into the existing framework of subspecialties. Vascular imaging champions are required, whether ordered into dedicated service lines or attached to conventional subspecialty silos. Complicating matters, indications for imaging examinations can be rather varied, including specific attention on the vessels themselves, (atherosclerotic disease to vasculitis) or diseases of the end-organs (stroke, myocardial infarct, mesenteric ischemia).

Over that last 30 years, our field has witnessed tremendous advances in imaging technologies that have promptly changed the practice of cardiovascular imaging, shifting markedly from invasive catheter angiography to noninvasive imaging. Radiologist practices, for the most part, have seen noninvasive vascular imaging far outpace invasive imaging, especially as these techniques have improved in their reliability and effectiveness. Although imaging has recently been scrutinized as a cost center, noninvasive diagnosis is strikingly cost-effective, particularly compared to invasive angiography and surgical procedures undertaken without the benefit of the road map that imaging provides.

These technologies continue to rapidly evolve with dramatic changes even in the last five years, which persist in shaping our clinical practices. However, the non-invasive technologies have not translated into all radiology practices with equal vigor. This non-adoption is due, in part, to the pervasive nature of vascular disease that impacts so many radiological subspecialties, as well as the roles that several imaging modalities play. Ultrasound, CT, and MRI each have complementary functions and strengths, such that screening, definitive diagnosis, and disease management often require more than one. It is difficult to find any subspecialty or individual radiologist with mastery of all these modalities, much less the ability to translate their latest advancements into practice.

One prevailing question is how to achieve high-level vascular imaging across the wide range of clinical radiology. Ultimately, developing new service lines is exceedingly challenging, especially in the modern era where the pressures of relative value unit-based productivity dominate our practices. The activation barrier is high. Nevertheless, I believe that pursuit of diagnostic excellence is an endeavor worth committing a career to. Our patients count on it. No other specialties are prepared to carry this torch with imaging.

I also believe radiologists possess a unique skill set and are well-positioned to be champions of multimodality imaging diagnosis. Many of us have been trained as master diagnosticians—to recognize and analyze disease, exploiting the strengths of and overcoming the weaknesses in individual imaging modalities. No, artificial intelligence doesn’t stand a chance without us.