Research ArticleImaging

Added Value of Digital over Analog PET/CT: More Significant as Image Field of View and Body Mass Index Increase

Shirin Hatami, Sarah Frye, Anna McMunn, Crystal Botkin, Razi Muzaffar, Kara Christopher and Medhat Osman
Journal of Nuclear Medicine Technology December 2020, 48 (4) 354-360; DOI: https://doi.org/10.2967/jnmt.120.244160

Article Figures & Data

Figures

  • FIGURE 1.
    FIGURE 1.

    Skull–to–mid-thigh FOV indicates significant difference in scan time and 18F-FDG dose between Vereos and Gemini. No significant difference in DLP was observed. P values, percentages of change (differences), and decreases (↓) in corresponding values are indicated. Error bars are indicated as 5%.

  • FIGURE 2.
    FIGURE 2.

    Head-to-toe (whole body) FOV for Vereos indicates significant difference in scan time compared with Gemini. P values, percentages of changes (differences), and decreases (↓) in corresponding values are indicated. Error bars are indicated as 5%.

  • FIGURE 3.
    FIGURE 3.

    Scan time for digital and analog PET/CT systems according to BMI group. Total scan time shows significant difference between the 2 scanners (P < 0.001; 33% reduction). Largest difference was among obese patients, and least difference was among normal-weight patients. P values, percentages of changes (differences), and decreases (↓) in corresponding values are indicated. Error bars are indicated as 5%.

  • FIGURE 4.
    FIGURE 4.

    DLP for digital and analog PET/CT systems according to BMI group. Significant difference was observed in overweight and obese groups but not in underweight or normal-weight groups. P values, percentages of changes (differences), and increases (↑) or decreases (↓) in corresponding values are indicated. Error bars are indicated as 5%.

  • FIGURE 5.
    FIGURE 5.

    18F-FDG dose for digital and analog PET/CT systems according to BMI group. Significantly lower doses were observed in normal-weight, overweight, and obese groups but not in underweight group. P values, percentages of changes (differences), and decreases (↓) in corresponding values are indicated. Error bars are indicated as 5%.

  • FIGURE 6.
    FIGURE 6.

    Comparisons between Gemini weight-based dosing, Vereos weight-based dosing, and Vereos BMI-based dosing. Significant difference is seen between analog and digital weight-based dosing systems and between digital weight-based and digital BMI-based dosing systems. P values, percentages of changes (differences), and decreases (↓) in corresponding values are indicated. Error bars are indicated as 5%.

Tables

  • TABLE 1

    Variable Photon Counting Time per Frame for Analog PET Scanner for Different BMIs

    Time per frame
    FramesBMI < 20BMI, 20–24.9BMI, 25–29.9BMI, 30–35BMI > 35
    1–1060 s60 s90 s120 s180 s
    11–1830 s30 s30 s30 s60 s
  • TABLE 2

    Photon Counting Time per Frame for Digital PET Scanner Based on BMIs

    FOVTime per frame in regular-body protocol (BMI ≤ 34)Time per frame in large-body protocol (BMI > 34)
    Skull to mid thigh (frame 1–10)75 s105 s
    Lower extremity (11–18)37 s45 s
  • TABLE 3

    Mean, SD, and P value for 18F-FDG Dose, Scan Time, and DLP for Gemini Vs. Vereos PET/CT Scanner Regarding Different FOVs

    18F-FDG dose (MBq)Scan time (s)DLP (mGy/cm)
    FOVGeminiVereosPGeminiVereosPGeminiVereosP
    Skull to mid thigh443.26 (91.95)370.00 (46.46)<0.0011,342.24 (510)836.40 (139.2)<0.001463.33 (162.14)424.38 (115)NS
    Whole body411.99 (95.30)355.94 (62.24)<0.0011,619.95 (595.8)1,083.24 (180.6)<0.001702.22 (261.36)567.46 (144.28)<0.001

    • NS = not significant.

    • Data are mean followed by SD in parentheses. P values were determined by t test.

  • TABLE 4

    Mean, SD, and P Value for 18F-FDG Dose, Scan Time, and DLP for Gemini Vs. Vereos PET/CT ScannerAmong Different BMI Groups

    18F-FDG dose (MBq)Scan time (s)DLP (mGy/cm)
    BMI (kg/m2)GeminiVereosPGeminiVereosPGeminiVereosP
    Total422.3 (91.3)358.53 (59.55)<0.0011,567 (588)1,036 (198.6)<0.001656.72 (262.30)540.2 (149.63)<0.001
    Underweight (<18.9)209.05 (83.99)205.81 (76.71)NS981 (130.8)819 (124.8)NS289.37 (132.22)294.5 (102.16)NS
    Normal weight (19–24.9)345.21 (76.09)326.10 (63.63)0.0121,057 (156)963 (186)0.0014412.99 (102.51)455.69 (154.3)NS
    Overweight (25–29.9)438.45 (48.96)373.90 (42.69)<0.0011,336 (147.6)980 (139.2)<0.001597.85 (148.1)545.74 (132.4)<0.001
    Obese (>30)484.33 (52.57)384.90 (0.45)<0.0012,237 (484.8)1,179 (192)<0.001932.04 (170.1)623.35 (99.2)<0.001

    • NS = not significant.

    • Data are mean followed by SD in parentheses. P values were determined by t test.

  • TABLE 5

    Differences Between Gemini Weight-Based and Vereos Weight-Based Dose System (P < 0.001) and Between Vereos Weight-Based Dose System and Vereos BMI-Based Dose System (P < 0.001)

    Gemini weight-basedPVereos weight-basedPVereos BMI-basedP
    445.58 (72.57)<0.001374.07 (27.43)<0.001296 (56.75)<0.001

    • Data are mean 18F-FDG dose in megabecquerels, followed by SD in parentheses.

Back to top

In this issue

Print
Download PDF
Article Alerts
Email Article
Citation Tools
Bookmark this article

Jump to section

Keywords