title: [Usefulness of the modified Dixon technique associated with gadolinium administration in the characterization of adrenal masses].
abstract: We investigated the usefulness of modified Dixon technique at 0.5 T after Gadolinium (Gd) administration in the characterization of adrenal masses. One hundred and one patients (45 men, 56 women; mean age: 60.5 +/- 13.5 years) with 125 adrenal masses found at previous US or CT of the abdomen were submitted to MRI. The study protocol included preliminary T1-weighted, PD and T2-weighted SE images. A bolus of 0.1 mmol/kg Gd-DTPA was administered and then T1-weighted SE scans were acquired with modified Dixon technique (TR = 450-600 ms, TE = 30 ms, 192 x 192 matrix, no craniocaudal presaturation). Acquisition time is twice as long with this technique as with conventional SE sequences, but three sets of T1-weighted images are acquired: conventional SE, fat-suppressed and water-suppressed images. The diagnosis was made at surgery (18 lesions) and fine-needle biopsy (34 lesions), or with stable US follow-up findings for at least 1 year (73 masses). Adrenocortical adenomas (no. 88) were homogeneously isointense to liver in pre- and postcontrast images, but 32 of them exhibited a small high intensity spot in enhanced fat-suppressed images. Malignant lesions and pheochromocytomas (no. 19) had inhomogeneous signal intensity, with relatively higher signal on T2-weighted and Gd-enhanced fat-saturated images. Fat-water images were useful to assess fatty and myeloid components within myelolipomas (no. 7). Benign conditions were distinguished from malignant conditions with 90% sensitivity, 93% specificity and 92.5% diagnostic accuracy. To conclude, modified three-point Dixon technique after contrast agent administration appears to be another useful diagnostic application of midfield MRI to characterize adrenal tissues.
authors.affiliation: U.O. Radiodiagnostica II, Azienda Ospedaliera Pisana, Pisa. radiodiag2@inpe.unipi.it
authors.forename: P
authors.initials: P
authors.lastname: Boraschi
authors.forename: G
authors.initials: G
authors.lastname: Braccini
authors.forename: R
authors.initials: R
authors.lastname: Gigoni
authors.forename: F
authors.initials: F
authors.lastname: Cartei
authors.forename: A
authors.initials: A
authors.lastname: Campatelli
authors.forename: A D
authors.initials: AD
authors.lastname: Vito
authors.forename: G
authors.initials: G
authors.lastname: Perri
mesh_terms: D000293:Adolescent; D000307:Adrenal Gland Diseases / Q000473:pathology*; D000310:Adrenal Gland Neoplasms / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005682:Gadolinium; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged
chemical_list: D005682:Gadolinium