Radiology Coding Alert

Question: One of our patients had a CT scan of the abdomen and the pelvis on the same day. Her chief complaint was flank pain, and the radiology report indicated a renal stone. Neither of these conditions is listed in the diagnosis codes supporting medical necessity, and Medicare denied the claim. How can I code this to ensure payment?

New York Subscriber

Answer: There are three Medicare carriers and one fiscal intermediary for the state of New York. All four have local medical review policies for computerized axial tomography (CT) of the abdomen, CT of the pelvis, and CT of the abdomen and pelvis on the same date of service. Because the two CT studies were ordered on the same date of service, the third policy would be used to assess medical necessity. The policies for all four payers contain two ICD-9 codes that would probably be correct given the history provided. Code 788.0 (Renal colic) would be correct if the flank pain was of that type. In addition, 789.00 (Abdominal pain, unspecified site) is an allowable ICD-9 code if other tests (e.g., x-rays or urinalysis) were unable to determine the cause of pain. Payers monitor the use of this unspecified ICD-9 code on a postpayment, retrospective basis. Given the diagnosis in the radiology report of a renal stone and the clinical history of flank pain, the diagnosis of renal colic (788.0) is correct.

This case highlights the importance of gathering not only better quality clinical detail on the patient's signs and symptoms but also other details of the patient's care such as additional tests and studies.