Appeal type: Imaging
Decision: Unfavorable

We decided that the Plan does not have to pre-approve CTA, abdominal aorta and bilateral iliofemoral lower 
extremity runoff, with contrast material(s), including noncontrast images, if performed, and image 
postprocessing (CPT code 75635), for the enrollee. 
 
You asked the Plan to pre-approve the CTA testing. You say that the testing is necessary. The Plan denied your 
request. The Plan says the enrollee's records do not show low blood pressure at the ankles (Ankle-Brachial 
Index).; therefore, this test is not medically necessary. The Plan states if the enrollee's leg pain continues, other 
imaging tests can be done (Doppler ultrasound). 
 
The Plan must follow Medicare rules. Medicare rules say that CT scans are covered only when they are 
medically necessary.  
 
We asked our physician reviewer to carefully review the case file and apply the relevant Medicare rules to 
determine if the Plan was correct in denying the request to pre-approve the CTA testing. physician reviewer 
found the documentation indicates that the enrollee has bilateral venous stasis changes and edema of the lower 
extremities. On exam peripheral pulses are palpable and ABI studies were R 1.3 and L 1.48. CTA is another 
modality used to image arterial disease. Unfortunately, it still requires a large amount of contrast media, and an 
upgraded CT scanner is needed to reconstruct helpful images. CTA is another modality used to image arterial 
disease. It does have some pitfalls, such as the requirement for large amounts of contrast media, the necessity 
of synchronizing the image acquisition with the media administration, and the need for an upgraded CT scanner 
with postprocessing techniques to reconstruct helpful images. However, advances in technology now allow 
three-dimensional (3D) and four-dimensional (4D) reconstructions providing temporal information. A small 
study that evaluated the diagnostic accuracy of 'dynamic CTA' for lower-extremity PAOD found the 
sensitivity and specificity to be 98% and 97.1%, respectively, for diagnosing vessel stenosis, and 95.4% and 
99.3%, respectively, for diagnosing vessel occlusion.  These figures may be compared with the standard CTA 
sensitivities and specificities of 96.6% and 92.2%, respectively, for vessel stenosis and 94.4% and 94.4%, 
respectively, for occlusion investigators demonstrated a clear improvement in diagnostic accuracy for 
peripheral arterial occlusive disease (PAOD) with dynamic CTA over standard CTA, without increased 
radiation or contrast administration. In this case the enrollee's ankle brachial index (ABIs) are above 0,9. There 
is no specific clinical rationale for the requested CT scan. There is no evidence of occlusive disease. The 
review has determined that CT Scan is not medically reasonable or necessary. 

We looked at this physician's review, the file, and Medicare rules. Based on this information, we decided that 
Medicare rules for coverage of the CTA testing have not been met. Therefore, we decided that the Plan does 
not have to pre-approve CTA, abdominal aorta and bilateral iliofemoral lower extremity runoff, with contrast 
material(s), including noncontrast images, if performed, and image postprocessing (CPT code 75635), for the 
enrollee.