Radiology Coding Alert

CPT Code 93880 describes the gold standard for diagnostic cerebrovascular ultrasound, and coders must understand when to assign it as opposed to several related codes to optimize timely reimbursement.

Although there are various codes within the Non-invasive Vascular Diagnostic Studies section of CPT that describe cerebrovascular arterial studies, 93880 (duplex scan of extracranial arteries; complete bilateral study) far and away describes the test of choice, explains Richard Brebner, BS, RDMS, RDCS, RVT, vice president and technical director for Ultrasound Services Inc., which provides portable diagnostic ultrasound services in Pennsylvania, Delaware and New Jersey. It is ordered when a physician suspects an arterial occlusion, stenosis or similar condition. Well use ultrasound to look at the carotid artery and provide an initial evaluation concerning the condition of the vessel.

The ultrasound study defined in 93880 focuses on vessels positioned on the outside of the skull (i.e., extracranial), according to Rob Levin, CHBME, chief operating officer for Billing Solutions Inc., in Newtown, Pa., which provides medical billing services to
Ultrasound Services. A Doppler study uses sound waves to measure blood flow, he explains. However, a duplex scan as described in CPT 93880 adds an anatomical component to the flow measurement, which allows a sonographer to see plaque buildup that is causing a partial or complete blockage, while listening to the blood flow.

Brebner notes that code 93882 ( unilateral or limited study) is most frequently assigned when a follow-up study is ordered not as the initial diagnostic test. When a cerebrovascular problem is initially suspected, the bilateral study typically is ordered, because the requesting physician will want a full and complete study of both carotid arteries. Once the suspected blockage is found and treated, a limited study will likely be ordered for that specific site to ascertain the success of the procedure.

Coding the Exam of Vessels in the Skull

One of the challenges sonographers encounter during cerebrovascular studies occurs when the patients blockage cant be located extracranially. Code 93880 describes scans covering the clavicle to the foramen where the vessels enter the skull, Brebner explains. Beyond that point, the major arteries lie beneath the skull, which does not allow ultrasound investigation in the same manner as the extracranial circulation studies. The terminal branches cant be visualized through the cranium during the scan, he says.

To identify arterial blockages or vascular spasm within the skull, an intracranial scan may be performed, 93886 (transcranial Doppler study of the intracranial arteries; complete study). This study will be conducted to further discern where the blockage or spasm is located, he explains. The sonographer will place a narrow probe at several spots on the head behind the ear, for instance, or between the eye and nose. These areas [...]