Basics of CPT code 74177 & 74175

Computed Tomography or CT exam are very frequently done in radiology. CT exams are very helpful in diagnosing harmful diseases  or disorder. In Radiology, we have already learnt about coding chest x-ray, MRI CPT codes, Ultrasound exam etc. so now we focus on coding CT exam. As a coder, many of us have a confusion about coding CT exam and CTA (Computed Tomography Angiography). CT codes like CPT code 74177 and CTA codes like CPT codes 74175 have big difference in medical coding. A simple difference is that CTA is angiography studies and looks for blood vessel diseases while CT exam looks for disorder of soft tissue of the particular site.

If you are clear with the use of these codes, it will really benefit you for preparing for medical coding certification exam. The CPT codes used are different based on the site examined.  Let us check more about them.

Main Difference between CT (eg. CPT code 74177) and CTA exam (eg. CPT code 74175)

CT exam is not focused on blood vessels, they are used for diagnosing other disorders like pleural effusion, atelectasis, pneumonia, neoplasm etc. CT exam can also give more information regarding diseases and disorder of soft tissues.

CPT Assistant (“Coding Brief: Computed Tomography of Abdomen and Pelvis,” November 2011) describes a typical encounter for CPT code 74177 as, “A 66-year-old female with a history of non-Hodgkins lymphoma presents with flank and abdominal pain. Previous examination(s) demonstrated abnormally enlarged abdominal and retroperitoneal lymph nodes. A CT scan of the abdomen and pelvis with intravenous contrast is ordered.” It details a typical encounter for 74178 as, “A 50-year-old male presents with vague flank pain and persistent hematuria on serial urinalyses. There is no history of trauma. A CT scan of the abdomen and pelvis with and without contrast is ordered.”

Report a single CPT code (74176, 74177, 74178) per claim. In the unusual case that a patient undergoes more than one combined study per day and the services are documented appropriately, you may report both combined studies, with modifier 59, Distinct procedural service, appended to the second code. CPT Assistant (November 2011) specifies, “Although it would be rare, combination CT abdomen/pelvis studies may be performed in the morning followed by combination CT abdomen/pelvis studies performed later on the same day. In that instance, the second combined code should be reported with modifier 59 to denote to the payer that this is not a duplicate bill, but that separate and distinct combined studies were performed during different sessions by the same physician on the same patient on the same day.

CTA are used for finding diagnosis in the blood vessel (angiography). CPT code for Angiography are always high paid procedure and procedure are also little complex. For example, the CTA exam of chest is always done with use of three-dimensional (3D) or MIP (Maximum Intensity Projection) images to find pulmonary embolism in the arteries. Use of 3D or MIP images is mandatory for any CTA exam, if not we have query the physician.  For CTA exam, do not report any primary diagnosis other than related to blood vessel it can be denied from the payers. CTA exam are mainly for finding occlusion or thrombosis in the blood vessel and hence the diagnosis code should be from this category. CT exams are done for wide range of disorders.

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Difference between CT and CTA exam

Let us check this procedure with an example. We know about CT Chest and CTA chest exam. There is only one CPT code for CTA chest exam while we have three CPT codes for CT chest exam. Below are the CPT codes used for CT and CTA chest exam.

71250 – CT chest without contrast (oral contrast are considered without contrast)

71260 – CT chest with contrast (only IV contrast is considered with contrast)

71270 – CT chest with and without contrast

71275 – CTA chest without and with contrast.

As you can see above the CPT codes, you can easily differentiate one thing, the use of contrast. CTA exam is done only without and with contrast, there is no other way the exam is performed. For CT chest, we straight away have three CPT codes depending on the use of Contrast. Do always remember only IV (intravenous) contrast are considered as with contrast exam, while Oral contrast are considered as without contrast exam. So, if a CT chest exam is performed with oral contrast, we will use only 71250 CPT code, not 71260.

As per AMA coding guidelines, oral and/or rectal contrast administration alone does not qualify as a study “with contrast,” which applies to those procedures performed using contrast material administered intravascularly, intra-articularly, or intrathecally.

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Example for CT (CPT code 74177) and CTA exam (CPT code 74174 & 74175) for Abdomen and Pelvis (CT Urogram)

74176 – CT Abdomen Pelvis without contrast

74177 – CT abdomen Pelvis with contrast

74178 – CT  abdomen Pelvis without and with contrast

74174 – CTA Abdomen Pelvis without and with contrast

74175 – CTA Abdomen without and with contrast

Report 74176 when both studies (abdomen and pelvis) are performed without contrast. Apply CPT code 74177 if both studies are performed with contrast. Use 74178 if one or both studies is/are performed without contrast, followed by further sections using contrast material(s); and, when one study (of either the abdomen or pelvis) is performed without contrast, and the second study is performed with contrast.

Just remember, we do not use separate CPT code for abdomen and pelvis when we have a combined code for both. So, if an exam is performed on both abdomen and pelvis do use a combined CPT code from above list for CT and CTA exam.