Predictive accuracy of single‐ and multi‐slice MRI for the estimation of total visceral adipose tissue in overweight to severely obese patients

Abstract

The quantification of visceral adipose tissue (VAT) is increasingly being considered for risk assessment and treatment monitoring in obese patients, but is generally time-consuming. The goals of this work were to semi-automatically segment and quantify VAT areas of MRI slices at previously proposed anatomical landmarks and to evaluate their predictive power for whole-abdominal VAT volumes on a relatively large number of patients. One-hundred and ninety-seven overweight to severely obese patients (65 males; body mass index, 33.3 ± 3.5 kg/m(2); 132 females; body mass index, 34.3 ± 3.2 kg/m(2)) underwent MRI examination. Total VAT volumes (VVAT-T ) of the abdominopelvic cavity were quantified by retrospective analysis of two-point Dixon MRI data (active-contour segmentation, visual correction and histogram analysis). VVAT-T was then compared with VAT areas determined on one or five slices defined at seven anatomical landmarks (lumbar intervertebral spaces, umbilicus and femoral heads) and corresponding conversion factors were determined. Statistical measures were the coefficients of variation and standard deviations σ1 and σ5 of the difference between predicted and measured VAT volumes (Bland-Altman analysis). VVAT-T was 6.0 ± 2.0 L (2.5-11.2 L) for males and 3.2 ± 1.4 L (0.9-7.7 L) for females. The analysis of five slices yielded a better agreement than the analysis of single slices, required only a little extra time (4 min versus 2 min) and was substantially faster than whole-abdominal assessment (24 min). Best agreements were found at intervertebral spaces L3-L4 for females (σ5/1 = 523/608 mL) and L2-L3 for males (σ5/1 = 613/706 mL). Five-slice VAT volume estimates at the level of lumbar disc L3-L4 for females and L2-L3 for males can be obtained within 4 min and were a reliable predictor for abdominopelvic VAT volume in overweight to severely adipose patients. One-slice estimates took only 2 min and were slightly less accurate. These findings may contribute to the implementation of analytical methods for fast and reliable (routine) estimation of VAT volumes in obese patients.

Equation to estimate visceral adipose tissue volume based on anthropometry for workplace health checkup in Japanese abdominally obese men

“…Furthermore, in this study, we used Bland-Altman analysis to assess the accuracy of our VAT volume prediction equation. Only one study by Schaudinn et al 22 ) investigated a prediction equation for VAT volume in obese patients. They showed a mean VAT bias between −55~232 ml for males and −61~161 ml for females.…”

Segmentation and quantification of adipose tissue by magnetic resonance imaging

“…Data acquisition protocols for AT quantification vary from the use of a single-slice [124], a stack of slices (2D multi-slice or 3D volume acquisition) across a limited anatomical region (typically the abdomen) [125], or a whole body (head-to-feet) approach [37, 126]. Protocols centered at and about the L2-L3 and L4-L5 lumbar intervertebral spaces, as well as at the umbilicus, are the most popular choices for single and multi-slice protocols in CT and MRI.…”

“…Measurements of total AT area at the level of the head of the humerus and at the head of the femur yielded similarly strong correlations with total body AT volumes. Schaudinn et al [125] recently evaluated the predictive accuracy of single and multi-slice MRI in the estimation of abdominopelvic VAT volume in 197 overweight and obese patients (BMI range 25–39 kg/m 2 ) using a 10-mm slice thickness and a small 0.5-mm interslice gap, nearly-contiguous protocol. Single-slice area measurements were made at the level of each of the following landmarks: intervertebral spaces at L1 through L5 and at S1, umbilicus, and femoral head.…”

Assessment methods of body composition

“…Prethodne studije su zasnovane na činjenici da se mrko masno tkivo razlikuje od belog po frakciji zasićenih i nezasićenih masnih kiselina, kao i sadržaju vode [48]. Smatra se da se volumen ukupnog supkutanog masnog tkiva može se proceniti jednim poprečnim presekom na nivou L5-S1 ili 5 cm ispod [47,49]. Razlikujemo nekoliko vrsta magnetne resonance, koje se koriste u zavisnosti od ciljeva istraživanja i dostupnosti same metode.…”

“…Danas se magnetna rezonanca jačine 1,5 do 3 Tesla koristi u večini kliničkih istraživanja, dok se skeneri jačine 7 Tesla sve više koriste u specijalizovanim centrima, gde se sprovode imidžing i spektorskopske eksperimentalne studije. Selektivna magnetna rezonanca u kombinaciji sa magnetnom rezonancom celog tela može da razdvaja i kvantifikuje volumene grupa adipocita pronađenih u skeletnom mišićnom kompartmanu, kao i količinu triglicerida u i izvan skeletnih mišićnih vlakana [49]. Kvanititativna magnetna rezonanca je dragocen metod za kvantifikovanje malih promena u masnoj masi [50].…”