Contrast-enhanced ultrasound (CEUS) for differentiating between hepatocellular and cholangiocellular carcinoma.

PURPOSE: HCC and CC are the most common primary malignancies of the liver. There is only minimal evidence as to whether these two entities can be reliably differentiated by contrast-enhanced ultrasound. MATERIALS AND METHODS: We retrospectively analyzed the CEUS pattern of 39 patients with HCC, 11 patients with intrahepatic cholangiocarcinoma (ICC), 3 patients with Klatskin tumor, and 4 patients with gallbladder carcinoma. CEUS was performed using a standardized protocol (low MI, SonoVue®) with documentation of the arterial, portal-venous, and late phase. Besides the contrast enhancement compared to the adjacent normal liver tissue in every phase, the specific contrast pattern during the arterial phase (complete filling, incomplete filling of different grade, rim sign) was analyzed. RESULTS: Most HCC and ICC showed hyperenhancement during the arterial phase, with hypoenhancement or isoenhancement in the portal-venous and late phase. Hyperenhancement during the portal-venous phase was only observed in some cases of HCC, but not in ICC. In the case of arterial hyperenhancement, HCC showed complete filling more often than ICC. In the case of incomplete filling, the area of contrast-enhanced tumor in most HCCs was larger than in ICCs. A rim sign was present in only less than half ICCs, but in no HCCs. CONCLUSION: HCC and ICC differ to some extent in their CEUS enhancement pattern. Incomplete arterial hyperenhancement is more often seen in ICC than in HCC. A rim sign seems to be specific for ICC, but is only rarely present. However, in a case-to-case decision, due to overlapping characteristics, a reliable differentiation between the two tumor types by CEUS alone is very often not possible.

Hemodynamics in nailfold capillaries of patients with systemic scleroderma: synchronous measurements of capillary blood pressure and red blood cell velocity.

There is increasing evidence that endothelial damage occurs at a very early stage during the course of systemic scleroderma. Endothelial damage is accompanied by impaired microvascular function, which has clearly failed in patients with systemic scleroderma, as evidenced by necrosis of the fingertips in severe cases. We investigated two important determinants of microvascular function, namely capillary blood pressure and capillary red blood cell velocity, simultaneously in the same capillary. In patients with systemic scleroderma and in healthy volunteers matched for age and sex, capillary blood pressure was measured by direct cannulation and capillary red blood cell velocity by video microscopy. Capillary blood pressure and capillary red blood cell velocity were significantly lower in patients (14.27 +/- 4.34 mmHg, 230 +/- 310 microm per s) than in healthy controls (19.06 +/- 3.69 mmHg, p < 0.008, and 910 +/- 240 microm per s, p < 0.003) at an ambient temperature of 22 degrees C, whereas no significant difference in skin temperature was observed (23.7 +/- 0.9 degrees C vs 24.7 +/- 1.9 degrees C) and no occlusion of finger arteries was detected. Capillary blood pressure in enlarged capillaries did not differ from that in normal-shaped capillaries in the patients (correlation of diameter and capillary blood pressure, R2 = 0.04), which was also the case with capillary red blood cell velocity (R2 = 0.13). Capillary pulse pressure amplitude and capillary red blood cell velocity showed a strong correlation (R2 = 0.81), suggesting that the pressure gradient across the capillary loop, which is the driving force for capillary red blood cell velocity, was mainly dependent on precapillary resistance. These observations reflect the inadequate microvascular function in systemic scleroderma, which may be due mainly to a pathophysiologic functional increase in precapillary resistance, even at comfortable ambient temperatures.