Renal Adiposity Does not Preclude Quantitative Assessment of Renal Function Using Dual-Energy Multidetector CT in Mildly Obese Human Subjects

Christopher M. Ferguson, Alfonso Eirin, Gregory J. Michalak, Fahim Hedayat, Abdelrhman M. Abumoawad, Ahmad F. Hedayat, Xiangyang Zhu, Stephen C Textor, Cynthia H McCollough, Lilach O Lerman

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Rationale and Objectives: Multidetector computed tomography (MDCT) is useful for measuring in the research setting single-kidney perfusion and function using iodinated contrast time-attenuation curves. Obesity promotes deposition of intrarenal fat, which might decrease tissue attenuation and thereby interfere with quantification of renal function using MDCT. The purpose of this study was to test the hypothesis that background subtraction adequately accounts for intrarenal fat deposition in mildly obese human subjects during renal contrast enhanced dynamic CT. Materials and Methods: We prospectively recruited seventeen human subjects stratified as lean or mildly obese based on body mass index below or over 30 kg/m2, respectively. Renal perfusion was quantified from CT-derived indicator-dilution curves after background subtraction. Dual-energy MDCT images were postprocessed to generate iodine and virtual-noncontrast datasets, and the ratios between kidney/aorta CT numbers and iodine values calculated as surrogates of renal function. Results: Subcutaneous adipose tissue was increased in obese subjects. Virtual-noncontrast maps revealed in obese patients a decrease in basal cortical and medullary attenuation. Overall, basal attenuation inversely correlated with body mass index, in line with renal fat deposition. Contrarily, the kidney/aorta CT attenuation (after background subtraction) and kidney/aorta iodine ratios were similar between lean and obese subjects and correlated directly. These observations show that following background subtraction, the CT number reliably reflects basal tissue attenuation. Conclusion: Therefore, our findings support our hypothesis that background subtraction enables reliable assessment of kidney function in mildly obese subjects using MDCT, despite decreased basal attenuation due to renal adiposity.

Original languageEnglish (US)
JournalAcademic Radiology
DOIs
StateAccepted/In press - Jan 1 2019

Fingerprint

Adiposity
Kidney
Multidetector Computed Tomography
Iodine
Aorta
Fats
Body Mass Index
Perfusion
Subcutaneous Fat
Obesity

Keywords

  • Dual Energy Computed Tomography
  • Intrarenal fat
  • Iodine maps
  • Obesity
  • Renal perfusion

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Cite this

Renal Adiposity Does not Preclude Quantitative Assessment of Renal Function Using Dual-Energy Multidetector CT in Mildly Obese Human Subjects. / Ferguson, Christopher M.; Eirin, Alfonso; Michalak, Gregory J.; Hedayat, Fahim; Abumoawad, Abdelrhman M.; Hedayat, Ahmad F.; Zhu, Xiangyang; Textor, Stephen C; McCollough, Cynthia H; Lerman, Lilach O.

In: Academic Radiology, 01.01.2019.

Research output: Contribution to journalArticle

@article{28e9ff2b692545b7bcc56009053a8354,
title = "Renal Adiposity Does not Preclude Quantitative Assessment of Renal Function Using Dual-Energy Multidetector CT in Mildly Obese Human Subjects",
abstract = "Rationale and Objectives: Multidetector computed tomography (MDCT) is useful for measuring in the research setting single-kidney perfusion and function using iodinated contrast time-attenuation curves. Obesity promotes deposition of intrarenal fat, which might decrease tissue attenuation and thereby interfere with quantification of renal function using MDCT. The purpose of this study was to test the hypothesis that background subtraction adequately accounts for intrarenal fat deposition in mildly obese human subjects during renal contrast enhanced dynamic CT. Materials and Methods: We prospectively recruited seventeen human subjects stratified as lean or mildly obese based on body mass index below or over 30 kg/m2, respectively. Renal perfusion was quantified from CT-derived indicator-dilution curves after background subtraction. Dual-energy MDCT images were postprocessed to generate iodine and virtual-noncontrast datasets, and the ratios between kidney/aorta CT numbers and iodine values calculated as surrogates of renal function. Results: Subcutaneous adipose tissue was increased in obese subjects. Virtual-noncontrast maps revealed in obese patients a decrease in basal cortical and medullary attenuation. Overall, basal attenuation inversely correlated with body mass index, in line with renal fat deposition. Contrarily, the kidney/aorta CT attenuation (after background subtraction) and kidney/aorta iodine ratios were similar between lean and obese subjects and correlated directly. These observations show that following background subtraction, the CT number reliably reflects basal tissue attenuation. Conclusion: Therefore, our findings support our hypothesis that background subtraction enables reliable assessment of kidney function in mildly obese subjects using MDCT, despite decreased basal attenuation due to renal adiposity.",
keywords = "Dual Energy Computed Tomography, Intrarenal fat, Iodine maps, Obesity, Renal perfusion",
author = "Ferguson, {Christopher M.} and Alfonso Eirin and Michalak, {Gregory J.} and Fahim Hedayat and Abumoawad, {Abdelrhman M.} and Hedayat, {Ahmad F.} and Xiangyang Zhu and Textor, {Stephen C} and McCollough, {Cynthia H} and Lerman, {Lilach O}",
year = "2019",
month = "1",
day = "1",
doi = "10.1016/j.acra.2018.12.008",
language = "English (US)",
journal = "Academic Radiology",
issn = "1076-6332",
publisher = "Elsevier USA",

}

TY - JOUR

T1 - Renal Adiposity Does not Preclude Quantitative Assessment of Renal Function Using Dual-Energy Multidetector CT in Mildly Obese Human Subjects

AU - Ferguson, Christopher M.

AU - Eirin, Alfonso

AU - Michalak, Gregory J.

AU - Hedayat, Fahim

AU - Abumoawad, Abdelrhman M.

AU - Hedayat, Ahmad F.

AU - Zhu, Xiangyang

AU - Textor, Stephen C

AU - McCollough, Cynthia H

AU - Lerman, Lilach O

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Rationale and Objectives: Multidetector computed tomography (MDCT) is useful for measuring in the research setting single-kidney perfusion and function using iodinated contrast time-attenuation curves. Obesity promotes deposition of intrarenal fat, which might decrease tissue attenuation and thereby interfere with quantification of renal function using MDCT. The purpose of this study was to test the hypothesis that background subtraction adequately accounts for intrarenal fat deposition in mildly obese human subjects during renal contrast enhanced dynamic CT. Materials and Methods: We prospectively recruited seventeen human subjects stratified as lean or mildly obese based on body mass index below or over 30 kg/m2, respectively. Renal perfusion was quantified from CT-derived indicator-dilution curves after background subtraction. Dual-energy MDCT images were postprocessed to generate iodine and virtual-noncontrast datasets, and the ratios between kidney/aorta CT numbers and iodine values calculated as surrogates of renal function. Results: Subcutaneous adipose tissue was increased in obese subjects. Virtual-noncontrast maps revealed in obese patients a decrease in basal cortical and medullary attenuation. Overall, basal attenuation inversely correlated with body mass index, in line with renal fat deposition. Contrarily, the kidney/aorta CT attenuation (after background subtraction) and kidney/aorta iodine ratios were similar between lean and obese subjects and correlated directly. These observations show that following background subtraction, the CT number reliably reflects basal tissue attenuation. Conclusion: Therefore, our findings support our hypothesis that background subtraction enables reliable assessment of kidney function in mildly obese subjects using MDCT, despite decreased basal attenuation due to renal adiposity.

AB - Rationale and Objectives: Multidetector computed tomography (MDCT) is useful for measuring in the research setting single-kidney perfusion and function using iodinated contrast time-attenuation curves. Obesity promotes deposition of intrarenal fat, which might decrease tissue attenuation and thereby interfere with quantification of renal function using MDCT. The purpose of this study was to test the hypothesis that background subtraction adequately accounts for intrarenal fat deposition in mildly obese human subjects during renal contrast enhanced dynamic CT. Materials and Methods: We prospectively recruited seventeen human subjects stratified as lean or mildly obese based on body mass index below or over 30 kg/m2, respectively. Renal perfusion was quantified from CT-derived indicator-dilution curves after background subtraction. Dual-energy MDCT images were postprocessed to generate iodine and virtual-noncontrast datasets, and the ratios between kidney/aorta CT numbers and iodine values calculated as surrogates of renal function. Results: Subcutaneous adipose tissue was increased in obese subjects. Virtual-noncontrast maps revealed in obese patients a decrease in basal cortical and medullary attenuation. Overall, basal attenuation inversely correlated with body mass index, in line with renal fat deposition. Contrarily, the kidney/aorta CT attenuation (after background subtraction) and kidney/aorta iodine ratios were similar between lean and obese subjects and correlated directly. These observations show that following background subtraction, the CT number reliably reflects basal tissue attenuation. Conclusion: Therefore, our findings support our hypothesis that background subtraction enables reliable assessment of kidney function in mildly obese subjects using MDCT, despite decreased basal attenuation due to renal adiposity.

KW - Dual Energy Computed Tomography

KW - Intrarenal fat

KW - Iodine maps

KW - Obesity

KW - Renal perfusion

UR - http://www.scopus.com/inward/record.url?scp=85059864441&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85059864441&partnerID=8YFLogxK

U2 - 10.1016/j.acra.2018.12.008

DO - 10.1016/j.acra.2018.12.008

M3 - Article

C2 - 30655055

AN - SCOPUS:85059864441

JO - Academic Radiology

JF - Academic Radiology

SN - 1076-6332

ER -