[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.
Davy-Miallou
C
C
C.H.U. Pitié, Service de Radiologie Centrale, Paris.
Guinet
C
C
Bellin
M F
MF
Curet
P
P
Grellet
J
J
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.