[Artifacts in MR Imaging due to ventilation tubes].
Artifacts in MR Imaging due to ventilation tubes.


OBJECTIVE
MR examinations may be necessary in patients under artificial ventilation. Possible imaging artifacts originating from ventilation tubing made from silicone are demonstrated.


METHODS
In silicone carbohydrate residues are bound to silicon atoms. In silicone gels they give strong signals in MR imaging. MR signals from more solid silicone rubber are only possible if the carbohydrate residues in the molecular chain retain a sufficient mobility. To investigate whether silicone tubes give signals in MR images, different tubes for ventilation made from silicone and polyester were examined at 1.5 T (Gyroscan ACS NT, Powertrak 6000 gradients) with MR imaging and spectroscopy (MRS: PRESS, TE = 20 ms; relaxation time measurements: MIXED sequence; imaging: FFE [gradient echo] and TSE sequences).


RESULTS
Using short TE (</= 4 ms), tubes and sockets made from silicone could be imaged with FFE and SE sequences. An SE sequence with a short TE = 4 ms provided a sufficient signal intensity to depict the tube clearly besides brain tissue of a volunteer. When foldover occurred, the signal of the tube was projected onto the brain tissue. MR spectra confirmed that the image signal originated from the carbohydrate residues of the silicone molecule chains, not from residual water in the tube wall material. T(2) determinations indicate a multiexponential relaxation including a large component with a short TE (</= 15 ms). Tubes made from a polyester elastomere did not show up in MR images.


CONCLUSIONS
In MR images acquired with very short echo times silicone in ventilation tubes may produce significant artifacts.
Kugel
H
H
Institut und Poliklinik für Radiologische Diagnostik, Universität zu Köln, Germany. kugel@uni-muenster.de
Steppan
G
G
Zaro Weber
O
O
Krug
B
B
D000328:Adult; D000776:Anesthesiology / Q000295:instrumentation*; D016477:Artifacts; D001921:Brain / Q000473:pathology; D004867:Equipment Design; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D011091:Polyesters; D012121:Respiration, Artificial / Q000295:instrumentation*; D012828:Silicones
D011091:Polyesters; D012828:Silicones