February 28, 2006

ACR Radiology Coding Source™ January-February 2006 Q and A

Q: How do you code for a nuchal translucency measurement when performed in conjunction with a complete first trimester OB ultrasound exam?

A: If performed during the same session, it would be appropriate to report 76801 for the complete first trimester OB ultrasound and 76999 for the nuchal translucency measurement. 

The American College of Obstetrics & Gynecology submitted a request to establish a new code for 2007 to describe a nuchal translucency measurement. This measurement is a method for detecting fetal chromosomal abnormalities (eg, Downs syndrome) in the first trimester. The ACR commented during the CPT discussion of this new code that it felt that a limited OB code 76815 would appropriately describe this procedure. However, the CPT Editorial Panel felt a separate code was warranted and established a code for 2007. Because the editorial panel feels that a nuchal translucency measurement should be described by a separate and distinct code (which means that currently it is not accurately described by an existing code), the ACR recommends the use of the unlisted procedure code until the new Category I code approved for 2007 is released. 

Q: How do you code for diffusion-tensor imaging and diffusion-weighted imaging when performed with MRI brain imaging? Are there specific codes to describe this imaging?

A: When diffusion tensor imaging (DTI) is performed at the same setting as a routine brain MRI, the brain MRI code should be coded only once. However, in the unusual circumstance in which a patient had a routine brain MRI performed and a request is then later received to specifically perform DTI at a separately distinct imaging session, then it would be appropriate to report each study using a brain MRI code since this took place at two separate scanning sessions. DTI involves scanning the patient and a large amount of post-processing. 

Unlike DTI, diffusion-weighted imaging (DWI) is considered a routine sequence of MRI, such as fluid-attenuated inversion recovery (FLAIR), and should not be coded separately. A DWI sequence typically adds minimal additional time to both image acquisition and physician interpretation and, when performed, should be considered an inherent part of the base MRI study. 

Q: How do I code for the use of computer-aided detection (CAD) performed in conjunction with an MRI of the breast?

A: At this time, the unlisted procedure code 76498 should be used to describe CAD when performed in conjunction with an MRI of the breast. The MRI of the breast is reported separately using code 76093 (unilateral) or 76094 (bilateral). 

Note that 3-dimensional reconstructions, subtraction and angiodynamic assessment performed in conjunction with CAD are included in the CAD procedure base code and are not coded separately. The 3-D imaging is an inherent and intrinsic part of the CAD software and is thus included in the unlisted procedure code 76498. In this setting, 3D imaging should not be separately reported by CPT® codes 76376 (3-D rendering with interpretation and reporting of computed tomography, magnetic resonance imaging, ultrasound, or other tomographic modality; not requiring image postprocessing on an independent workstation) or 76377 (3-D rendering with interpretation and reporting of computed tomography, magnetic resonance imaging, ultrasound, or other tomographic modality; requiring image postprocessing on an independent workstation). 

A category III add-on code (+0159T) was recently approved by the CPT Editorial Panel to describe the use of CAD for MRI of the breast which will become effective for use July 1, 2006. This new code will similarly include all inherent 3-D imaging (which should not be reported separately with 76376 or 76377). Until July 1, however, the unlisted CPT code should be assigned to describe this additional work.