The conversion from ICD-9 codes to ICD-10 is almost here, and radiologists should expect a 6-fold increase in the number of codes they use, according to a recent study published in the Journal of the American College of Radiology.

The transition from more than 14,000 codes to almost 70,000 will have an “enormous technological, operational and financial impact,” according to study’s authors.

“As the conversion from ICD-9 to ICD-10 will require acquiring and documenting even more detailed clinical information than is currently required for billing purposes—information that remains difficult for many radiology practices to adequately capture—that transition is perceived as a particularly daunting task for facilities, physicians, administrators, and coders alike,” wrote Margaret Fleming, MD, department of radiology and imaging sciences at the Emory University School of Medicine in Atlanta, and colleagues.

For their study, the authors analyzed claims data from over 588,000 radiology services performed in 2014 by a large academic health system.

The data showed that 3,407 different ICD-9 codes were reported as the primary diagnosis for a radiology service in 2014, representing over 24% of the total number of codes. Looking more closely, 37 (0.3%) codes were assigned in 50% of the radiology services, and 348 (2.5%) codes were reported in 90% of the radiology services.

Using a Medicare-endorsed code translation tool, the authors then “manually and individually” translated each ICD-9 code from the 90th percentile to its potential ICD-10 counterpart. Those 348 ICD-9 codes became 2,048 ICD-10 codes.

“We project that radiology practices will experience a 6-fold increase in the number of codes, and they will need to become sufficiently familiar with them to adequately and compliantly bill for their services,” the authors wrote.

Fleming and colleagues also divided the data into departments. Their data shows that musculoskeletal imaging will see the biggest increase as a result of the transition, going from 146 ICD-9 codes to 4,199 ICD-10 codes. Emergency imaging is another big category, going from 137 to 1,036.

The subspecialty impacted the least? Breast imaging would go from 11 ICD-9 codes to 12 ICD-10 codes.

“Practices are advised to prioritize their ICD-10 educational and operational conversion initiatives to areas that will experience the largest impact from this transition,” the authors wrote.