TY - JOUR
T1 - Pseudolesion of the bile duct caused by flow effect
T2 - A diagnostic pitfall of MR cholangiopancreatography
AU - Sugita, Reiji
AU - Sugimura, Eriko
AU - Itoh, Michiaki
AU - Ohisa, Toshihiro
AU - Takahashi, Syouki
AU - Fujita, Naotaka
PY - 2003/2/1
Y1 - 2003/2/1
N2 - OBJECTIVE. Our objective was to examine the influence of the shape of imaged structures and the velocity of flow on the appearance of flow artifacts seen on MR cholangiopancreatography (MRCP) in a phantom model. MATERIALS AND METHODS. Three types of phantoms representing the biliary system were constructed. The first phantom type was a straight tube; the second, a single tube in which the inlet and outlet diameters varied by a ratio of as much as 1:6; and the third, a tube that simulated a stricture in the biliary system and a gallstone. All experiments were repeated three times. RESULTS. We did not observe any flow artifacts in the experiments we performed with the straight tubes. A higher rate of flow resulted in decreased signal intensity in tubes simulating bile ducts; the decreased signal was most likely to be observed on images in which the speed of flow exceeded 5 mm/sec. Flow artifacts were seen only if the ratio between the inlet and outlet diameters was 1:4 or greater. Simulations of bile duct abnormalities - such as a 50% stricture or the presence of a gallstone - did not produce any flow artifacts. CONCLUSION. In our experiments, a flow artifact could be seen on images in which the ratio between the inlet and the outlet diameters in the phantom was equal to or greater than 1:4. This finding indicates that a flow artifact could be observed in dilated bile ducts on MRCP under clinical conditions. Knowing that a pseudo-filling defect can be caused by a flow artifact should help to prevent misinterpretation of MRCP images.
AB - OBJECTIVE. Our objective was to examine the influence of the shape of imaged structures and the velocity of flow on the appearance of flow artifacts seen on MR cholangiopancreatography (MRCP) in a phantom model. MATERIALS AND METHODS. Three types of phantoms representing the biliary system were constructed. The first phantom type was a straight tube; the second, a single tube in which the inlet and outlet diameters varied by a ratio of as much as 1:6; and the third, a tube that simulated a stricture in the biliary system and a gallstone. All experiments were repeated three times. RESULTS. We did not observe any flow artifacts in the experiments we performed with the straight tubes. A higher rate of flow resulted in decreased signal intensity in tubes simulating bile ducts; the decreased signal was most likely to be observed on images in which the speed of flow exceeded 5 mm/sec. Flow artifacts were seen only if the ratio between the inlet and outlet diameters was 1:4 or greater. Simulations of bile duct abnormalities - such as a 50% stricture or the presence of a gallstone - did not produce any flow artifacts. CONCLUSION. In our experiments, a flow artifact could be seen on images in which the ratio between the inlet and the outlet diameters in the phantom was equal to or greater than 1:4. This finding indicates that a flow artifact could be observed in dilated bile ducts on MRCP under clinical conditions. Knowing that a pseudo-filling defect can be caused by a flow artifact should help to prevent misinterpretation of MRCP images.
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U2 - 10.2214/ajr.180.2.1800467
DO - 10.2214/ajr.180.2.1800467
M3 - Article
C2 - 12540453
AN - SCOPUS:0037305665
VL - 180
SP - 467
EP - 471
JO - The American journal of roentgenology and radium therapy
JF - The American journal of roentgenology and radium therapy
SN - 0361-803X
IS - 2
ER -