[MRI of the normal portal system: the artefacts. Apropos of 45 cases].
The protal system of 45 normal patients have been retrospectively studied on spin echo MRI sequences (interleaved cuts): multiple artifacts have been evaluated and 24% of them were visualized at the portal system level. Thus, partial volume effect responsible for almost 25% of the artifacts is not always easily seen on a single sequence. Respiratory and aortic artifacts can deteriorate the visualization of the vascular lumen but cannot be confused with a thrombosis. Well-known artifacts, as slice entry phenomenon and even echo rephasing, represent more than 60% of the artifacts: they are readily recognized when they are typical and indicate flowing blood. On the contrary, an other artifact, representing less than 5% of the total and seen at the level of the left portal vein, simulates a thrombus, on T2 weighed images. We conclude that the frequency and polymorphism of the artifacts are limiting factors of MRI value in the diagnosis of portal vein thrombosis.
C.H.U. Pitié, Service de Radiologie Centrale, Paris.
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C
Davy-Miallou
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C
Guinet
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Bellin
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Curet
J
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Grellet
D000328:Adult; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000009:adverse effects; D008297:Male; D011168:Portal System / Q000033:anatomy & histology*; D012189:Retrospective Studies; D013927:Thrombosis / Q000175:diagnosis*
Aspect normal du système porte en IRM: les artefacts. A propos de 45 témoins.