TY - JOUR
T1 - A new phantom using polyethylene glycol as an apparent diffusion coefficient standard for MR imaging
AU - Matsuya, Ryohei
AU - Kuroda, Masahiro
AU - Matsumoto, Yoshitsugu
AU - Kato, Hirokazu
AU - Matsuzaki, Hidenobu
AU - Asaumi, Junichi
AU - Murakami, Jun
AU - Katashima, Kazunori
AU - Ashida, Masakazu
AU - Sasaki, Takanori
AU - Sei, Tetsuro
AU - Himei, Kengo
AU - Katsui, Kuniaki
AU - Katayama, Norihisa
AU - Takemoto, Mitsuhiro
AU - Kanazawa, Susumu
AU - Mimura, Seiichi
AU - Oono, Seiichiro
AU - Kitayama, Takuichi
AU - Tahara, Seiji
AU - Inamura, Keiji
PY - 2009/10
Y1 - 2009/10
N2 - In recent years, magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) has seen wide clinical use, such as for early detection of cerebrovascular diseases and whole body screening for tumors. The apparent diffusion coefficient (ADC) standard phantom, which mimics the ADC values of several lesions in the body, is indispensable for the development of new pulse sequences for DWI, such as diffusion-weighted whole-body imaging with background body-signal suppression (DWIBS). However, information on the ADC values of the previously reported ADC standard phantoms is limited, because these phantoms were made using only a few different materials at a limited range of concentrations, and the ADC values were measured only at certain temperatures. It has been considered difficult, if not impossible, to create a phantom that provides arbitrary ADC values, because it is difficult to calculate the concentrations of the materials and the temperature at ADC measurement. In this study, we used polyethylene glycol (PEG) as a phantom material, and developed an empirical formula to calculate the PEG concentration at any measurement temperature to obtain arbitrary ADC values of the phantom. DWI images of phantoms made using seven different PEG concentrations were taken under heating from 17 to 46°C at 1°C intervals. Using ADC values calculated from these DWI images, we developed two empirical formulas: i) an empirical formula to calculate the ADC values of phantoms made using any PEG concentration at any measurement temperature; and ii) an empirical formula to calculate PEG concentrations to obtain arbitrary ADC values at any measurement temperature. We inspected the accuracy of these empirical formulas by newly made PEG phantoms. A comparison between the ADC values calculated with the empirical formulas and the measured ADC values confirmed the high accuracy of these formulas. PEG phantoms are safe, inexpensive and easy to make, compared with the previously reported ADC standard phantoms. Our empirical formulas enable us to calculate PEG concentrations that provide arbitrary ADC values at any measurement temperature. The empirical formulas could be used within a range of ADC values from 0.37x10-3 to 3.67x10-3 mm2/s, PEG concentrations from 0 to 120 mM, and measurement temperatures from 18 to 45°C. Using these formulas, it would be possible to make standard phantoms that mimic the ADC values of any clinical lesions. The PEG phantom might thus be an excellent new ADC standard phantom for MRI with DWI.
AB - In recent years, magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) has seen wide clinical use, such as for early detection of cerebrovascular diseases and whole body screening for tumors. The apparent diffusion coefficient (ADC) standard phantom, which mimics the ADC values of several lesions in the body, is indispensable for the development of new pulse sequences for DWI, such as diffusion-weighted whole-body imaging with background body-signal suppression (DWIBS). However, information on the ADC values of the previously reported ADC standard phantoms is limited, because these phantoms were made using only a few different materials at a limited range of concentrations, and the ADC values were measured only at certain temperatures. It has been considered difficult, if not impossible, to create a phantom that provides arbitrary ADC values, because it is difficult to calculate the concentrations of the materials and the temperature at ADC measurement. In this study, we used polyethylene glycol (PEG) as a phantom material, and developed an empirical formula to calculate the PEG concentration at any measurement temperature to obtain arbitrary ADC values of the phantom. DWI images of phantoms made using seven different PEG concentrations were taken under heating from 17 to 46°C at 1°C intervals. Using ADC values calculated from these DWI images, we developed two empirical formulas: i) an empirical formula to calculate the ADC values of phantoms made using any PEG concentration at any measurement temperature; and ii) an empirical formula to calculate PEG concentrations to obtain arbitrary ADC values at any measurement temperature. We inspected the accuracy of these empirical formulas by newly made PEG phantoms. A comparison between the ADC values calculated with the empirical formulas and the measured ADC values confirmed the high accuracy of these formulas. PEG phantoms are safe, inexpensive and easy to make, compared with the previously reported ADC standard phantoms. Our empirical formulas enable us to calculate PEG concentrations that provide arbitrary ADC values at any measurement temperature. The empirical formulas could be used within a range of ADC values from 0.37x10-3 to 3.67x10-3 mm2/s, PEG concentrations from 0 to 120 mM, and measurement temperatures from 18 to 45°C. Using these formulas, it would be possible to make standard phantoms that mimic the ADC values of any clinical lesions. The PEG phantom might thus be an excellent new ADC standard phantom for MRI with DWI.
KW - Apparent diffusion coefficient value
KW - Diffusion-weighted imaging
KW - Magnetic resonance imaging
KW - Polyethylene glycol
KW - Standard phantom
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U2 - 10.3892/ijo-00000404
DO - 10.3892/ijo-00000404
M3 - Article
C2 - 19724927
AN - SCOPUS:70449434533
VL - 35
SP - 893
EP - 900
JO - International Journal of Oncology
JF - International Journal of Oncology
SN - 1019-6439
IS - 4
ER -