Mind the fat: MRI quantifies adipose tissue

MRI can accurately detail the amount and distribution of adipose tissue, and quantification of this tissue with imaging could be used in the study of metabolic syndrome and diabetes, according to a study published in the May issue of Academic Radiology.

While its known that obesity contributes to serious health issues, quantification of obesity using anthropometric measurements such as body mass index and body circumference are limited, according to, Michalis Mantatzis, MD, PhD, of University Hospital of Alexandroupolis in Greece.

“Although these measurements can be easily acquired, they are not precise, they may suffer from systematic errors, and they cannot accurately assess the most crucial [adipose tissue] compartment, that is, the VAT [visceral adipose tissue], proven to be closely related with the development of metabolic syndrome,” wrote the authors.

Mantatzis sought to use a basic MRI protocol for quantitative assessment of various adipose tissues, and conducted a study featuring 76 male volunteers, half with diabetes (group A) and half without (group B). The groups were matched for body mass index, and all subjects underwent abdominal MRI with a 3D spoiled gradient echo T1-weighted sequence.

The authors found diabetic patients had larger amounts of intraperitoneal and retroperitoneal adipose tissue when compared with nondiabetic subjects, though this association was not statistically significant. However, the association between diabetes and overall VAT measurements was significant. Calculations of intraperitoneal and retroperitoneal adipose tissue on a workstation after manual segmentation were well correlated with waist circumference, body mass index and body fat percentage.

“It maybe speculated that fat from both intraabdominal compartments, that is, intraperitoneal and retroperitoneal are implicated in the pathogenesis of diabetes. On the other hand, SAT [subcutaneous adipose tissue] did not exhibit differences between the two groups of the study; thus, SAT does not seem to have a role in the pathogenesis of diabetes."

Mantatzis and colleagues noted that a set of images through the abdomen at the level of L3 and L4 vertebrae is preferable to a single slice when measuring the distribution of fat in the body.

“MR has the potential for expanded clinical application in this area provided that the cost, availability, and duration of the examination could be adjusted,” they wrote.