ABSTRACT
PURPOSE: To compare enhancement of liver parenchyma in MR imaging after injection of hepatocyte-specific contrast media. MATERIALS AND METHODS: Patients (n = 295) with known/suspected focal liver lesions randomly received 0.025 mmol gadoxetic acid/kg body weight or 0.05 mmol gadobenate dimeglumine/kg body weight by means of bolus injection. MR imaging was performed before and immediately after injection, and in the delayed phase at approved time points (20 min after injection of gadoxetic acid and 40 min after injection of gadobenate dimeglumine). The relative liver enhancement for the overall population and a cirrhotic subgroup was compared in T1-weighted GRE sequences. An independent radiologist performed signal intensity measurements. Enhancement ratios were compared using confidence intervals (CIs). RESULTS: The relative liver enhancement in the overall population was superior with gadoxetic acid (57.24%) versus gadobenate dimeglumine (32.77%) in the delayed-imaging phase. The enhancement ratio between the contrast media was statistically significant at 1.75 (95% CI: 1.46-2.13). In the delayed phase, the enhancement of cirrhotic liver with gadoxetic acid (57.00%) was comparable to that in the overall population. Enhancement with gadobenate dimeglumine was inferior in cirrhotic liver parenchyma (26.85%). CONCLUSION: In the delayed, hepatocyte-specific phase, liver enhancement after injection of gadoxetic acid was superior to that obtained with gadobenate dimeglumine.
Subject(s)
Gadolinium DTPA , Liver Neoplasms/pathology , Liver/pathology , Magnetic Resonance Imaging/methods , Meglumine/analogs & derivatives , Organometallic Compounds , Adult , Aged , Aged, 80 and over , Contrast Media , Double-Blind Method , Europe , Humans , Injections, Intra-Arterial , Middle Aged , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
The aim of this study was to compare low-field MRI (0.2 T) and conventional radiography for the detection of acute fractures of the distal part of the extremities. X-ray and MRI examinations of 78 (41 fractures, 37 without fracture) patients with the clinical suspicion of an acute fracture in the distal part of the extremities were compared. Four experienced radiologists, two for each of the two modalities, independently analyzed the images. Interobserver variability and receiver operating characteristic (ROC) analysis for both methods were established. The MRI and conventional radiography revealed an accuracy of 81.4 and of 79.5%, respectively, in the detection of acute fractures. The diagnostic accuracy of MRI to detect fractures in the hand and forefoot proved to be significantly inferior to conventional X-ray examinations. On the other hand, MRI achieved a better accuracy for the examination of bones near a large joint. The interobserver variability for both methods was rated as moderate. In ROC analysis both methods were rated as good. There was no statistical difference of the accuracy between low-field MRI and conventional radiography in the detection of acute fractures of the distal part of the extremities. Consequently, a routine use of low-field MRI as an alternative to conventional radiography to diagnose acute fractures of the extremities seems not to be justified.
