Ultrasound scoring system for diabetes

According to a study published on March 6th in Ultrasound in Medicine and Biology, there is only one technique to assess medial arterial calcification (MAC) from an ultrasound scan that can also predict cardiovascular and diabetes complications.

The researchers evaluated two methods for diagnosing MAC severity:

  • The presence of MAC in three unique artery segments
  • The length of MAC in centimeters

The researchers found that only MAC identified through the segmentation method was able to predict independently whether the patient would also suffer from peripheral artery disease and diabetic nephropathy. Nonetheless, the authors noted that both methods for calculating MAC using ultrasound scans were valuable.

“Consistent with previous studies, the presence and severity of MAC were associated with diabetic complications in our univariate analysis, regardless of whether the length or segmentation method was used,” wrote the researchers, led by Jing Tian from Sun Yat-Sen Memorial Hospital in Guangzhou, China.

Ultrasound is a viable tool for screening patients with diabetes for MAC; however, medical practitioners have not come to a consensus on the best scoring method to evaluate MAC severity from ultrasound scans. Thus, the investigators chose to compare two common scoring systems: the segmentation method and the length method.

Using the length method, MAC severity is determined based off of the severity of calcification in a 4-cm scanned area. A MAC length of 0 cm, less than 1 cm, 1 to 2 cm, 2 to 3 cm, and greater than 3 cm on ultrasound scans correspond to MAC scores of 0, 1, 2, 3, and 4, respectively. These scores are then added up. Higher scores indicate higher MAC severity.

The investigators used both types of MAC scoring methods on 359 patients with type 2 diabetes who stayed at a hospital endocrinology department between March 2015 and December 2017. The bilateral lower limb artery ultrasound examinations were performed by a radiologist with 15 years of clinical ultrasound experience.

Based on the ultrasound scan findings, 37% of tested patients had MAC. However, the diagnosis of mild and severe MAC differed based on the scoring method. When using the length method, the researchers discovered 105 mild MAC cases and 123 severe cases. On the other hand, the segmentation method found 98 mild cases and 130 severe ones.

Both methods were effective at predicting the odds of diabetic complications, including peripheral artery disease, peripheral neuropathy, retinopathy, and nephropathy. However, the segmentation method was an independent predictor of peripheral artery disease and diabetic nephropathy, suggesting it may be better for evaluating cardiovascular abnormalities and risk of diabetes complications.“MAC scores calculated by the segmentation method were significantly correlated with and diabetic nephropathy,” the researchers concluded. “The segmentation method for assessing MAC may be a valuable tool in clinical work.”