Comparison of magnetic resonance imaging measurements of abdominal aortic aneurysms with measurements obtained by other imaging techniques and intraoperative measurements: possible implications for endovascular grafting.
OBJECTIVE
Abdominal aortic aneurysm morphologic evaluation with conventional imaging techniques is inadequate when endovascular repair is being contemplated. This study has addressed the problem with magnetic resonance imaging (MRI).


METHODS
Twenty patients (14 men, 6 women) with a median age of 73 years were recruited and assessed according to current endovascular graft selection criteria. Thirteen patients subsequently underwent open aneurysmorrhaphy, and the intraoperative parameters have been compared with those of duplex ultrasonography and MRI.


RESULTS
No significant difference was demonstrated in the diameter of the infrarenal neck among ultrasonography, MRI, and intraoperative findings (p > 0.05, Mann Whitney U Test) and also during assessment of infrarenal neck length; however, duplex sonography accurately defined the renal ostia in only five cases. MRI visualized 38 of 40 renal arteries. Distal aortic involvement (cuff diameter and length) and the length and diameter of the common iliac arteries were accurately determined by MRI in all cases, and no significant difference was demonstrated with the intraoperative findings. Comparison of the intraoperative and MRI aneurysm lengths suggested a slight trend of overestimation by MRI resulting from angulation of the aneurysm, but this figure did not reach statistical significance. Only two patients met the current criteria for endoluminal straight grafting.


CONCLUSIONS
Both MRI and duplex sonography accurately predicted aortic morphologic characteristics; however, MRI provided the most comprehensive anatomic picture for patient selection and should be considered the nonionizing imaging modality of choice when an endovascular repair is being contemplated.
Department of Surgery, Royal United Hospital, Bath, United Kingdom.
A D
AD
Fox
M S
MS
Whiteley
P
P
Murphy
J S
JS
Budd
M
M
Horrocks
D000368:Aged; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000473:pathology; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000601:surgery; D001807:Blood Vessel Prosthesis; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D015607:Stents; D018616:Ultrasonography, Doppler, Duplex