Quantitative Imaging of Body Composition

Abstract

Body composition refers to the amount and distribution of lean tissue, adipose tissue, and bone in the human body. Lean tissue primarily consists of skeletal muscle; adipose tissue comprises mostly abdominal visceral adipose tissue and abdominal and nonabdominal subcutaneous adipose tissue. Hepatocellular and myocellular lipids are also fat pools with important metabolic implications. Importantly, body composition reflects generalized processes such as increased adiposity in obesity and age-related loss of muscle mass known as sarcopenia.In recent years, body composition has been extensively studied quantitatively to predict overall health. Multiple imaging methods have allowed precise estimates of tissue types and provided insights showing the relationship of body composition to varied pathologic conditions. In this review article, we discuss different imaging methods used to quantify body composition and describe important anatomical locations where target tissues can be measured.

Prognostic Role of Low-Skeletal Muscle Mass on Staging Computed Tomography in Metastasized Colorectal Cancer: A Systematic Review and Meta-Analysis

“…Body composition is an ever-growing research field with a plethora of possible clinical and prognostic implications of LSMM throughout almost every field of medicine. [1][2][3][4][5][6][7][8][9][10][11][12] Especially oncological patients are at potential risk of sarcopenia/LSMM for several reasons. At first the cancer itself can cause muscle wasting and cachexia.…”

Subcutaneous and visceral fat assessment by DXA and MRI in older adults and children

“…DXA estimates the lowest L4/L5 section, whereas in MRI, four slices throughout the abdomen are averaged. DXA estimates a cross‐sectional area in one section from a planar mass‐calibrated DXA image versus the direct measure of cross‐sectional area from MRI and CT sections (39,40). The body regions and thickness of sections chosen for assessment and the separation technique to distinguish VAT from SAT also differ.…”

“…DXA estimates the lowest L4/L5 section, whereas in MRI, four slices throughout the abdomen are averaged. DXA estimates a cross-sectional area in one section from a planar mass-calibrated DXA image versus the direct measure of cross-sectional area from MRI and CT sections(39,40).The body regions and thickness of sections chosen for assessment and the separation technique to distinguish VAT from SAT also differ. Depending on the DXA make (GE vs. Hologic), the compartment location used for measurement by DXA may be smaller or larger than for MRI(6), e.g., GE DXA systems report VAT and SAT for the entire android region(33).As the specific fat measures in the current study are different from what many other studies define as regions of interest, both the absolute and the relative content of VAT are difficult to compare directly.…”

Intramuscular adipose tissue at level Th12 is associated with survival in COVID‐19

“…1,2 Body composition has been studied using a single computed tomography (CT) slice, which is considered the reference standard for quantitative body composition studies. 3,4 Abnormal body composition, and in particular sarcopenia, has been associated with survival in patients with cancer 5 or an increased cardiometabolic risk. 6 Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic of coronavirus disease 19 .…”