ABSTRACT
AIM: To clarify the detectability of hepatocellular carcinoma (HCC) on gadoxetic acid-enhanced MRI at 3 T with dual-source parallel radiofrequency (RF) excitation. MATERIALS AND METHODS: Twelve patients with 26 HCCs who each underwent multidetector row CT (MDCT), gadoxetic acid-enhanced MRI with dual-source parallel RF excitation, and angiography-assisted CT prior to living related-liver transplantation. Three blinded readers independently reviewed the images obtained by each imaging technique for the presence of HCC on a segment-by-segment basis using a five-point confidence scale. The area under the receiver operating characteristic curve (Az), sensitivity, and specificity were compared among the three techniques. RESULTS: The Az values of gadoxetic acid-enhanced MRI were highest for all readers, although no significant difference in Az value among the three methods was obtained. No significant differences in sensitivity or specificity were observed among the three techniques for each reader. CONCLUSION: Gadoxetic acid-enhanced MRI at 3 T with dual-source parallel RF excitation has relatively high-level diagnostic potential for the detection of HCC in patients with severe liver dysfunction, which was equivalent to that of MDCT and angiography-assisted CT. Dual-source parallel RF excitation would have a clinical impact on 3 T MRI of the liver.
Subject(s)
Carcinoma, Hepatocellular/diagnosis , Contrast Media , Gadolinium DTPA , Image Enhancement/methods , Liver Neoplasms/diagnosis , Magnetic Resonance Imaging/methods , Aged , Angiography , Carcinoma, Hepatocellular/complications , Diagnosis, Differential , Female , Humans , Image Processing, Computer-Assisted/methods , Liver/pathology , Liver Cirrhosis/complications , Liver Diseases/etiology , Liver Neoplasms/complications , Male , Middle Aged , Multidetector Computed Tomography/methods , Observer Variation , ROC Curve , Reproducibility of Results , Retrospective Studies , Sensitivity and Specificity , Severity of Illness Index , Tomography, X-Ray Computed/methodsABSTRACT
A double-walled carbon nanotube (DWNT) provides the simplest system to study the interaction between concentric layers in carbon nanotubes. The inner and outer walls of a DWNT can be metallic (M) or semiconducting (S), and each of the four possible configurations (M@M, M@S, S@S, S@M) has different electronic properties. Here we report, for the first time, detailed Raman spectroscopy experiments carried out on individual DWNTs, where both concentric tubes are measured under resonance conditions, in order to understand the dependence of their electronic and optical properties according to their configuration. Interestingly, for the three DWNTs that were studied, the inner-outer tube distance (e.g., 0.31-0.33 nm) was less than the interlayer spacing in graphite. We believe these results have important implications in the fabrication of electronic devices using different types of S and M tubular interconnects.
