Liver MRI in the hepatocyte phase with gadolinium-EOB-DTPA: does increasing the flip angle improve conspicuity and detection rate of hypointense lesions?

Autor: Bashir MR; Department of Radiology, Duke University Medical Center, Durham, North Carolina, USA., Husarik DB, Ziemlewicz TJ, Gupta RT, Boll DT, Merkle EM
Jazyk: angličtina
Zdroj: Journal of magnetic resonance imaging : JMRI [J Magn Reson Imaging] 2012 Mar; Vol. 35 (3), pp. 611-6. Date of Electronic Publication: 2011 Oct 27.
DOI: 10.1002/jmri.22850
Abstrakt: Purpose: To compare conspicuity and detection rate of hypointense lesions on T1-weighted (T1w) gradient echo (GRE) sequences with low and high flip angles (FA) in hepatocyte phase magnetic resonance imaging (MRI) using gadoxetate disodium.
Materials and Methods: This Health Insurance Portability and Accountability Act (HIPAA)-compliant study was Institutional Review Board (IRB)-approved. The study population consisted of patients with hypointense liver lesions undergoing MRI with gadoxetate disodium, with hepatocyte-phase fat suppressed 3D T1w GRE sequences at both low (10-12°) and high (30-35°) FA. Contrast-to-noise ratios (CNRs) were calculated for liver parenchyma vs. large lesions and common bile duct (CBD) vs. liver. Three radiologists each assigned a conspicuity score (CS) for each lesion detected at low or high FA. Paired Student's t-tests compared the lesion detection (LD) rate using only the hepatocyte phase data set compared with the entire MRI examination, and CS for low and high FA.
Results: In all, 57 large and 70 small lesions were identified in 18 patients. Average LD and CS were significantly greater at high FA versus low FA overall (LD 89.0% vs. 79.5%; CS 2.8 vs. 2.2; P < 0.05) and for small lesions (81.4% vs. 65.7%; 2.5 vs. 1.8; P < 0.05). Average liver-to-lesion CNR for large lesions and CBD-to-liver CNR was significantly greater at high FA (P < 0.05).
Conclusion: Increasing the FA in hepatocyte phase MRI with gadoxetate disodium improves hypointense lesion detection and conspicuity, particularly for small lesions.
(Copyright © 2011 Wiley-Liss, Inc.)
Databáze: MEDLINE
Externí odkaz: