PURPOSE: Hepatic pseudo-anisotropy is an artifact observed in hepatic diffusion-weighted imaging under respiratory triggering (RT-DWI). To determine the clinical significance of this phenomenon, hepatic RT-DW images were reviewed. METHODS: One hundred and five MR examinations, including RT-DWI, were assessed. The patient group included 62 non-cirrhotic and 43 cirrhotic individuals. All images were evaluated by mutual agreement of two radiologists from the viewpoints of incidence of pseudo-anisotropy and correlation between pseudo-anisotropy and the quality of trace images. The ADC of normal hepatic parenchyma of non-cirrhotic livers were measured in both areas with and without pseudo-anisotropy. RESULTS: Pseudo-anisotropy was observed in 60% of non-cirrhotic (37/62) and 30% of cirrhotic (13/43) images. The difference between the two groups was statistically significant (P < 0.001). The quality of trace images showed a tendency to worsen as pseudo-anisotropy became significant. However, the quality of trace images was generally satisfactory, with only two patients whose trace images were difficult to interpret due to pseudo-anisotropy. The areas with pseudo-anisotropy showed higher ADC than those without pseudo-anisotropy (P < 0.001). CONCLUSION: Pseudo-anisotropy is a type of artifact that originates from respiratory movement. Even though respiratory triggering is employed, ADC measurement of the liver is inaccurate because of pseudo-anisotropy, especially in non-cirrhotic patients.
PURPOSE: Hepatic pseudo-anisotropy is an artifact observed in hepatic diffusion-weighted imaging under respiratory triggering (RT-DWI). To determine the clinical significance of this phenomenon, hepatic RT-DW images were reviewed. METHODS: One hundred and five MR examinations, including RT-DWI, were assessed. The patient group included 62 non-cirrhotic and 43 cirrhotic individuals. All images were evaluated by mutual agreement of two radiologists from the viewpoints of incidence of pseudo-anisotropy and correlation between pseudo-anisotropy and the quality of trace images. The ADC of normal hepatic parenchyma of non-cirrhotic livers were measured in both areas with and without pseudo-anisotropy. RESULTS: Pseudo-anisotropy was observed in 60% of non-cirrhotic (37/62) and 30% of cirrhotic (13/43) images. The difference between the two groups was statistically significant (P < 0.001). The quality of trace images showed a tendency to worsen as pseudo-anisotropy became significant. However, the quality of trace images was generally satisfactory, with only two patients whose trace images were difficult to interpret due to pseudo-anisotropy. The areas with pseudo-anisotropy showed higher ADC than those without pseudo-anisotropy (P < 0.001). CONCLUSION: Pseudo-anisotropy is a type of artifact that originates from respiratory movement. Even though respiratory triggering is employed, ADC measurement of the liver is inaccurate because of pseudo-anisotropy, especially in non-cirrhotic patients.
Authors: R Bammer; S L Keeling; M Augustin; K P Pruessmann; R Wolf; R Stollberger; H P Hartung; F Fazekas Journal: Magn Reson Med Date: 2001-09 Impact factor: 4.668
Authors: T Sugahara; Y Korogi; M Kochi; I Ikushima; Y Shigematu; T Hirai; T Okuda; L Liang; Y Ge; Y Komohara; Y Ushio; M Takahashi Journal: J Magn Reson Imaging Date: 1999-01 Impact factor: 4.813
Authors: J Wang; S Takashima; F Takayama; S Kawakami; A Saito; T Matsushita; M Momose; T Ishiyama Journal: Radiology Date: 2001-09 Impact factor: 11.105
Authors: Thomas C Kwee; Taro Takahara; Isao Muro; Marc Van Cauteren; Yutaka Imai; Rutger A J Nievelstein; Willem P T M Mali; Peter R Luijten Journal: Jpn J Radiol Date: 2010-10-24 Impact factor: 2.374
Authors: João Pedro Filipe; Luís Curvo-Semedo; João Casalta-Lopes; Maria Cristina Marques; Filipe Caseiro-Alves Journal: MAGMA Date: 2012-10-06 Impact factor: 2.310
Authors: Mamak Eatesam; Susan M Noworolski; Phyllis C Tien; Michelle Nystrom; Jennifer L Dodge; Raphael B Merriman; Aliya Qayyum Journal: J Magn Reson Imaging Date: 2011-10-27 Impact factor: 4.813
Authors: Thomas C Kwee; Taro Takahara; Tetsu Niwa; Marko K Ivancevic; Gwenael Herigault; Marc Van Cauteren; Peter R Luijten Journal: MAGMA Date: 2009-09-02 Impact factor: 2.310
Authors: Stefano Palmucci; Giuseppina Cappello; Giancarlo Attinà; Giovanni Fuccio Sanzà; Pietro Valerio Foti; Giovanni Carlo Ettorre; Pietro Milone Journal: Biomed Res Int Date: 2015-03-19 Impact factor: 3.411
Authors: Se Jin Nam; Kae Young Park; Jeong-Sik Yu; Jae-Joon Chung; Joo Hee Kim; Ki Whang Kim Journal: Korean J Radiol Date: 2012-10-12 Impact factor: 3.500