Comparison of contrast-enhanced ultrasonography with virtual touch tissue quantification in the evaluation of focal liver lesions.

PURPOSE: To evaluate the diagnostic efficacy of virtual touch tissue quantification (VTQ) and contrast-enhanced ultrasonography (CEUS), separately and in combination, in diagnosing malignant focal liver lesions (FLLs). METHODS: Forty-six patients with 55 FLLs (28 benign and 27 malignant) underwent both VTQ and CEUS. The diagnostic values of VTQ and CEUS, alone and in combination, were compared. RESULTS: The diagnostic sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of CEUS were 92.6% (25/27), 96.4% (27/28), 94.5% (52/55), 96.2% (25/26), and 93.1% (27/29), respectively. The diagnostic sensitivity, specificity, accuracy, PPV, and NPV of VTQ with a cutoff of 2.22 m/s were 51.9% (14/27), 85.7% (24/28), 69.1% (38/55), 77.8% (14/18), and 64.9% (24/37), respectively. The diagnostic sensitivity, specificity, accuracy, PPV, and NPV of VTQ and CEUS combined were 96.3% (26/27), 82.1% (23/28), 89.1% (49/55), 83.9% (26/31), and 95.8% (23/24), respectively. Comparing the accuracies of the three methods, the diagnostic values of CEUS and of the combination of CEUS with VTQ were significantly higher than those of VTQ alone (p ≤ 0.01). There was no significant difference between the combination of CEUS with VTQ and CEUS (p = 0.49). CONCLUSIONS: CEUS is superior to VTQ in diagnosing malignant FLLs. Adding VTQ to CEUS did not improve the diagnosis of FLLs. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:347-353, 2016.

[Time-resolved FTIR study of amorphous process of nylon 6 with calcium chloride].

The influence of calcium chloride on the crystallinity of nylon 6 was studied by means of time-resolved FTIR, WADX and DSC. The results show that the crystallinity of nylon 6 decreased with the increase of CaCl2, and finally nylon 6 changed from crystal phase to amorphous phase. Because hydrogen bond is the main reason that nylon has three-dimensional ordered structure and forms crystalline phase, we further studied the changes of wave number of NH, amide I and amide II related to hydrogen bond in CaCl2/PA6 complexes by time-resolved FTIR. These studies indicate that in the chloroethanol solution of nylon 6 and calcium chloride, complex bonds between calcium cation and oxygen atom of carbonyl group gradually form, and calcium cations are inserted into the molecular chains of nylon 6, which weaken the hydrogen bonds between the molecular chains of nylon 6 and damage the three-dimensional ordered structure of nylon 6, so the crystallinity of nylon 6 decreases and nylon 6 changes from crystalline to amorphous phase.