Congress:
ECR25
Poster Number:
C-14414
Type:
Poster: EPOS Radiologist (scientific)
Authorblock:
M. Seguchi1, Y. Kanazawa2, T. Miyati3, H. Masafumi2, M. Miyoshi4, H. Hayashi3, Y. Kanematsu2, Y. Takagi2, A. Haga2; 1Toksuhima/JP, 2Tokushima/JP, 3Kanazawa/JP, 4Hino/JP
Disclosures:
Mayuka Seguchi:
Nothing to disclose
Yuki Kanazawa:
Nothing to disclose
Tosiaki Miyati:
Nothing to disclose
Harada Masafumi:
Nothing to disclose
Mitsuharu Miyoshi:
Employee: GE HealthCare
Hiroaki Hayashi:
Nothing to disclose
Yasuhisa Kanematsu:
Nothing to disclose
Yasushi Takagi:
Nothing to disclose
Akihiro Haga:
Nothing to disclose
Keywords:
MR physics, MR-Diffusion/Perfusion, Physics, Arteriosclerosis
Results
Viscosity measurement: Figure 4 shows the relationship between the glycerin concentration and measured viscosity at each temperature. As the concentration increased, viscosity also increased. Additionally, the viscosity increased as temperature decreased.
Fig 4: The relationship between glycerin concentrations and measured viscosities at each temperature. Line color represents temperatures: Blue, 24ºC; green, 37ºC; red, 40ºC.
DWI Signals: Figure 5 shows the b-value and normalized DWI signals. Increasing viscosity values based on material densities reduced ADCmono values. The DWI signals for each glycerin sample decreased with increasing b-values. The ADCmono fitting curves at high temperatures tended to deviate at a data point with a b-value of 1500 s/mm2.
Fig 5: The relationship between b-values and measured DWI signals at 37ºC. Line color represents glycerin concentrations; purple, 10 wt%; blue, 20 wt%; cyan, 30 wt%; green, 40 wt%; orange, 45 wt%; brown, 50 wt%; magenta, 55 wt%; red, 60 wt%.
Phantom Experiment: Figure 6 shows the relationship between ADCmono and viscosity at each temperature. The elucidated relationship was consistent with the Stokes-Einstein equation. The relationship at 37°C was used as the viscosity function in vivo.
Fig 6: The relationship between ADCmono and the measured viscosity at each temperature: (a) 24ºC, (b) 37ºC, and (c) 40ºC. Data is plotted using a DWI dataset of high accuracy fitting when calculating ADCmono.
Clinical Study: Figure 7 shows the results of our comparison of each finding. When comparing DWI viscosity with pathological findings for atherosclerotic plaques, a significant difference was observed between patients with and without symptoms (P < 0.01), and no significant difference was noted between those with and without hemorrhage. Symptoms (+) show high viscosity, and hemorrhages (+) show high viscosities spanning a broad data range.
Fig 7: Standard boxplots show viscosity values of different groups. Left shows the relationship between with and without symptom groups for atherosclerotic plaque patients. Right shows the relationship between with and without hemorrhage findings groups for atherosclerotic plaque patients. The number of each group is without symptom (Symptom -); eleven; with symptom (Symptom +), 16; without hemorrhage (Hemorrhage -), six; and with hemorrhage (Hemorrhage +), 21. **, P < 0.01; ns, not significant.
Figure 8 shows the relationship between each signal and the ADCmono. The left panel shows the negative correlation (R = -0.46) observed between T1 ratio and ADCmono. The right panel shows that no correlation exists between the T2 ratio and ADCmono. T1w exhibited variations from iso- to high-intensity signals. Signals depend on the hemorrhage water content with temporal changes. Thus, plaque viscosity is related to the blood coagulability of intraplaque hemorrhage.
Fig 8: Scatter plots of each normalized signal (e.g., T1 and T2 ratios) and ADCmono. The left plots show the relationship between the T1 ratio and ADCmono. The right plots show the relationship between the T2 ratio and ADCmono. The red points show a group with hemorrhage and the blue points show a group without hemorrhage.
