title: [Magnetic resonance in the study of suprarenal neoplasms. Qualitative and quantitative analysis of signal intensity].
abstract: BACKGROUND
  Magnetic Resonance Imaging (MRI) has been proposed as the diagnostic technique of choice to characterize adrenal tumors. However, the results of the current studies are controversial.
  
  
  METHODS
  Forty-nine patients with unilateral adrenal masses were submitted to MRI for lesion characterization on the basis of MR signal intensity. Cytology and/or histology demonstrated 14 pheochromocytomas (pheos), 11 adenomas, 3 cysts, 2 myelolipomas, 4 carcinomas, 3 metastases and 1 fibrosarcoma; a clinical diagnosis of adenoma was made in the remaining 11 patients. MR studies were performed using spin-echo (SE) sequences with T1 (TR/TE = 600/17 ms) and T2 (TR/TE = 2000/15-90 ms) weighting. T1-weighted images were also acquired after Gadolinium-DTPA (Gd-DTPA) administration. MR studies were integrated with in- and out-of-phase (TR/TE = 100/4-6 ms) chemical-shift (CS) sequences. MR signal intensity (SI) was analyzed qualitatively and quantitatively; MR results were correlated with tumor type and hormone secretion.
  
  
  RESULTS
  The qualitative analysis of T2 images showed high signal intensity in the majority (80%) of adrenal lesions (14 pheos, 12 adenomas, 3 cysts, 2 myelolipomas and 8 malignancies). The quantitative analysis of post-Gd-DTPA T1 images permitted to distinguish adenomas, cysts and myelolipomas from pheos and malignancies. The qualitative analysis of post-Gd-DTPA T2 and T1 images permitted to distinguish pheos and cysts from adenomas and malignancies (p < .05); however, pheos and cysts as well as adenomas and malignancies were not differentiated. MR SI was similar in secreting and nonsecreting adenomas from both a qualitative and a quantitative viewpoints. CS MRI permitted to distinguish adenomas (decreased signal intensity on out-phase relative to in-phase images) from other benign and malignant lesions (no signal change from out-phase to in-phase images).
  
  
  CONCLUSIONS
  The qualitative analysis of MR SI on conventional T1 and T2 images does not permit to differentiate adrenal masses. The qualitative evaluation of T1 images after Gd-DTPA administration, the quantitative analysis and CS sequences are technical options improving lesion characterization.
authors.affiliation: Istituto Nazionale dei Tumori, Università degli Studi Federico II, Napoli.
authors.forename: S
authors.initials: S
authors.lastname: Maurea
authors.forename: C
authors.initials: C
authors.lastname: Caracò
authors.forename: L
authors.initials: L
authors.lastname: Castelli
authors.forename: S
authors.initials: S
authors.lastname: Filice
authors.forename: B
authors.initials: B
authors.lastname: Alfano
authors.forename: F
authors.initials: F
authors.lastname: Ruffolo
authors.forename: M
authors.initials: M
authors.lastname: Ziviello
authors.forename: M
authors.initials: M
authors.lastname: Salvatore
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000473:pathology*; D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged
vernacular_title: La Risonanza Magnetica nello studio delle neoplasie surrenaliche. Analisi qualitativa e quantitativa dell'intensità del segnale.