Steady state evaluation of aortic dissections: A feasibility study.
OBJECTIVE
One the main reasons for the limited use of MRI in the evaluation of aortic dissection in emergency conditions is its long execution time. The authors report their experience regarding a new MRI sequence that reduces execution time and avoids the use of contrast medium.


METHODS
Eighteen haemodynamically stable patients with suspected (16 cases, 3 with confirmed diagnosis of aneurysm) or known aortic dissection (2 cases) underwent in emergency conditions 1.5T MRI with Steady-State sequence (Fast Imaging Employing Steady-State Acquisition: GRE 2D; TR 3.5, TE 1.6; Flip Angle 45, bandwidth 125, matrix 224x224, NEX 1, acquisition time per slice 7 s, thickness 6-8 mm, FOV 38; 2D-GE breath-hold sequence requiring cardiac triggering). The results obtained were compared in terms of diagnostic accuracy and execution time with those of classical MRI examination (black blood T1, FSE T2 and 3D MR-angiography) or multislice CT.


RESULTS
The diagnostic accuracy of MRI, both with Steady-State sequence and the ''classical'' technique, and multislice CT in the diagnosis of dissection or aneurysm is equal (100%), whereas execution time is 6, 25 and 6 minutes, respectively. Multislice CT proved to be more accurate than Steady-State MRI in evaluating the renal parenchyma and the extension of the dissection to the renal arteries.


CONCLUSIONS
The Steady-State MRI sequence provides a diagnosis of aortic dissection or aneurysmal dilatation in a short time and may represent a valuable alternative to CT in emergency settings, especially in patients with reported contraindications to iodinated contrast media.
De Cicco
Maria Luisa
ML
Radiologia DEA, Policlinico Umberto I, Università degli Studi di Roma La Sapienza, Roma. marialuisa.decicco@tiscali.it
Andreoli
Chiara
C
Casciani
Emanuele
E
Polettini
Elisabetta
E
Gualdi
Gian Franco
GF
D000208:Acute Disease; D000784:Aortic Dissection / Q000175:diagnosis*; D017545:Aortic Aneurysm, Thoracic / Q000175:diagnosis*; D004632:Emergency Medical Services / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed