TY - JOUR

T1 - Effect of blood glucose and body weight on image quality in brain [18F]FDG PET imaging

AU - Henriksen, Otto M.

AU - Holm, Søren

AU - Marner, Lisbeth

AU - Law, Ian

PY - 2020

Y1 - 2020

N2 - Objectives The aims of the present study were to assess the influence of mild to moderate hyperglycaemia and body weight on brain 2-[18F]fluoro-2-deoxy-d-glucose ([18F]FDG) PET, and to what extent a simple algorithm for maintaining count density may compensate for these effects. Methods We prospectively included 63 patients undergoing routine brain [18F]FDG PET. Scan time and injected activity were adjusted in patients with hyperglycaemia or increased body weight. Measures of perceived image quality, image noise and image contrast were obtained in both standard scans and intervention scans. Results Elevated blood glucose and increased body weight were associated with reduced count density and increased image noise that in turn were associated with lower scores of perceived image quality. The proposed simple algorithm effectively maintained the image noise level and improved perceived image quality across the full range of elevated blood glucose values and body weights, although the effect of intervention on perceived image quality was attenuated by lower image contrast in patients with moderate hyperglycaemia. In patients with increased body weight or blood glucose, the fraction of scans with poor image quality decreased from 9/29 to 2/29 (P = 0.04) and the fraction with good image quality increased from 7/29 to 20/29 (P = 0.001) when applying the proposed algorithm. Conclusions Increasing blood glucose and body weight are associated with increased image noise in standard imaging conditions. Improving count density by prolonging scan time and increasing injected activity significantly improves image quality in hyperglycaemic patients, although the image contrast remains reduced in patients with most pronounced hyperglycaemia.

AB - Objectives The aims of the present study were to assess the influence of mild to moderate hyperglycaemia and body weight on brain 2-[18F]fluoro-2-deoxy-d-glucose ([18F]FDG) PET, and to what extent a simple algorithm for maintaining count density may compensate for these effects. Methods We prospectively included 63 patients undergoing routine brain [18F]FDG PET. Scan time and injected activity were adjusted in patients with hyperglycaemia or increased body weight. Measures of perceived image quality, image noise and image contrast were obtained in both standard scans and intervention scans. Results Elevated blood glucose and increased body weight were associated with reduced count density and increased image noise that in turn were associated with lower scores of perceived image quality. The proposed simple algorithm effectively maintained the image noise level and improved perceived image quality across the full range of elevated blood glucose values and body weights, although the effect of intervention on perceived image quality was attenuated by lower image contrast in patients with moderate hyperglycaemia. In patients with increased body weight or blood glucose, the fraction of scans with poor image quality decreased from 9/29 to 2/29 (P = 0.04) and the fraction with good image quality increased from 7/29 to 20/29 (P = 0.001) when applying the proposed algorithm. Conclusions Increasing blood glucose and body weight are associated with increased image noise in standard imaging conditions. Improving count density by prolonging scan time and increasing injected activity significantly improves image quality in hyperglycaemic patients, although the image contrast remains reduced in patients with most pronounced hyperglycaemia.

KW - brain

KW - diabetes mellitus

KW - fluorodeoxyglucose F18

KW - hyperglycaemia

KW - PET

U2 - 10.1097/MNM.0000000000001281

DO - 10.1097/MNM.0000000000001281

M3 - Journal article

C2 - 32858605

AN - SCOPUS:85096152730

VL - 41

SP - 1265

EP - 1274

JO - Nuclear Medicine Communications

JF - Nuclear Medicine Communications

SN - 0143-3636

IS - 12

ER -