Radiology Coding Alert

Question: A 72-year-old patient was referred to our radiology practice to have an MRI without contrast performed on their brain. The patient is diagnosed with stage IIIb lung cancer in the hilar region and the order is to check if the cancer has metastasized to the brain. The radiologist found no indication of cancer in the brain tissue, but they did find T1 hypointense lesions on the patient’s parietal and right frontal bones.

How do I code the procedure and findings?

South Dakota Subscriber

Answer: You’ll want to start with the reason for the visit, which in this case is screening the patient’s brain for possible metastasis of lung cancer. In Chapter 21, “Factors Influencing Health Status and Contact with Health Services (Z00-Z99),” of the ICD-10-CM code set, you’ll find Z12.82 (Encounter for screening for malignant neoplasm of nervous system).

Your next step after locating the Z code will be to find the appropriate procedure code for the magnetic resonance imaging (MRI) scan without contrast. Within the Diagnostic Radiology (Diagnostic Imaging) section, you’ll find the Head and Neck subsection. A careful read of the descriptor for 70553 (Magnetic resonance (eg, proton) imaging, brain (including brain stem); without contrast material, followed by contrast material(s) and further sequences) will show you this CPT^® code meets the wording in your documentation.

The radiologist’s impression indicated cancer wasn’t present in the brain tissue, but they did find lesions in select skull bones. For this portion of the report, you should check the Table of Neoplasms in the ICD-10-CM code set and look for frontal and parietal under Bone in the Neoplasm column. You will then cross-reference these rows across to the Unspecified Behavior column to find D49.2 (Neoplasm of unspecified behavior of bone, soft tissue, and skin).

Lastly, you’ll code the lung cancer in the hilar region by checking the Table of Neoplasms for “hilus of lung,” which will direct you to parent code C34.0- (Malignant neoplasm of main bronchus). The parent code carries a 5th character required icon, so you’ll need to check the documentation or query the provider as to on what side the tumor is located.