Clinical Hemorheology and Microcirculation - Volume 63, issue 2

Authors: Rübenthaler, J. | Reimann, R. | Hristova, P. | Staehler, M. | Reiser, M. | Clevert, D.A.

Article Type: Research Article

Abstract: PURPOSE: The aim of this study was to analyse clear cell and papillary renal cell carcinoma (RCC) examined with contrast-enhanced ultrasound (CEUS) and a second generation blood pool agent (SonoVue® , Bracco, Milan, Italy) before clinical intervention. MATERIALS AND METHODS: A total of 41 patients with histologically proven subtypes of RCC were examined. 29 patients had a clear cell RCC and 12 patients showed a papillary RCC. Average size in the clear cell RCC group was 6.07 cm and 1.88 cm in the papillary RCC group. An experienced radiologist examined all patients with CEUS. The following parameters were analysed: …maximum signal intensity (PEAK), time elapsed until PEAK is reached (MTT), local blood flow (RBF), area under the time intensity curve (AUC) and the signal intensity (SI) during the course of time. For both groups all comparisons were made based on healthy renal parenchyma. RESULTS: In the clear cell RCC significant differences (significance level p  < 0.05) between cancerous tissue and the healthy renal parenchyma were noticed in all four parameters. The clear cell RCC showed a significant reduced blood volume. It reached the PEAK reading relatively rapidly and its signal intensity was always lower than that of the healthy renal parenchyma. In the arterial phase retarded absorption of the contrast agent was observed, followed by fast washing out of the contrast agent bubbles. In the papillary RCC group, significant findings as to PEAK and RBF as well as a slightly significant difference as to AUC were recorded. The papillary RCC had a lower blood supply and reached its PEAK reading later. Its signal intensity was also reduced. The signal intensity of papillary NCC was significantly lower compared with clear cell RCC; absorption and washing out of the contrast agent was delayed. CONCLUSION: CEUS seems to be an useful additional method to clinically differentiate between clear cell and papillary RCC. In daily clinical use, patients with contraindication for other imaging methods, especially the magnetic resonance imaging, might particularly benefit from this method. Show more

DOI: 10.3233/CH-152010

Citation: Clinical Hemorheology and Microcirculation, vol. 63, no. 2, pp. 89-97, 2016

Authors: Zimmermann, H. | Rübenthaler, J. | Rjosk-Dendorfer, D. | Helck, A. | Reimann, R. | Reiser, M. | Clevert, D.A.

Article Type: Research Article

Abstract: PURPOSE: To compare the value of a portable ultrasound system and a high end ultrasound system in detection of endoleaks after EVAR. MATERIAL AND METHODS: In this retrospective study, a cohort of 25 patients underwent both standard examination using a portable ultrasound system (Philips VISIQ) and a second examination using a high end ultrasound system (Philips EPIQ 7). The examination included B-mode and color Doppler in detection of endoleaks. Additional the maximum diameter of the aneurysm was measured in two planes (right-left and ventral-dorsal). The gold standard was contrast-enhanced ultrasound (CEUS) in detection of endoleaks. RESULTS: …25 patients were included in the study. Patients were predominantly male (n  = 23) with an average age of 73,30±7.82 years (range 54–85). Diameters of the treated aneurysms were in the right-left plane 5,32±1.88 cm and ventral-dorsal 4,99±1.78 cm using the high end system. Diameters of the treated aneurysms were in the right-left plane 5,30±1.82 cm and ventral-dorsal 4,87±1.74 cm using portable ultrasound system. In 80% of the cases CEUS could detect an endoleak. Whereas the high end system could detect in B-mode 40% and color Doppler 45% of the cases an endoleak. The portable system could detect in B-mode 30% and in color Doppler 35% of the cases an endoleak. On both systems in B-mode a false positive endoleak was found on the same patient. All high flow endoleaks, which needed intervention, could be detected on all systems. CONCLUSION: The high end ultrasound system does not seem to have an additional advantage in the measurement of the aneurysm diameter. Due to a higher resolution, more endoleaks could be detected in B-mode and color Doppler by using the high end system. The presence of small endoleaks could only be detected by using contrast enhanced ultrasound on an high end ultrasound system. High flow endoleaks could be reliable seen on both systems. Show more

Keywords: Endoleak, EVAR, AAA, CEUS, portable ultrasound system

DOI: 10.3233/CH-152011

Citation: Clinical Hemorheology and Microcirculation, vol. 63, no. 2, pp. 99-111, 2016

Authors: Wendl, C.M. | Janke, M. | Jung, W. | Stroszczysnski, C. | Jung, E.M.

Article Type: Research Article

Abstract: The aim of our study was to evaluate, whether the analysis of time intensity curves (TIC) of contrast enhanced ultrasound (CEUS) could help to differentiate between thyroid adenomas and carcinomas in daily clinical routine. B-mode, Colour Coded Doppler Sonography (CCDS), Power Doppler (PD) and CEUS were applied for 50 patients (27 men, 23 women; mean age 51 years, range 16–81 years). CEUS cine-sequences were analysed using time intensity curves (TIC) and calculating time to peak (TTP) as well as the area under the curve (AUC). All 20 patients with carcinomas presented with a complete wash-out in the …late phase of CEUS while this occurred only in three out of the 30 patients with adenomas. Marked differences were observed between adenomas and carcinomas concerning the mean AUC in the surrounding thyroid tissue (p  = 0.041). In addition, TTP differed clearly between the centre and the surrounding of the carcinomas (p  < 0.05) as well as between TTP in the border area and the surrounding tissue (p  = 0.01). CEUS in combination with TIC analysis allows a dynamic evaluation of the microvascularisation of thyroid nodules and is helpful for the differentiation of benign and malignant nodules. Show more

Keywords: Thyroid carcinoma, thyroid adenoma, contrast-enhanced ultrasound (CEUS), perfusion imaging, time-intensity-curve

DOI: 10.3233/CH-151966

Citation: Clinical Hemorheology and Microcirculation, vol. 63, no. 2, pp. 113-121, 2016

Authors: Kaliviotis, Efstathios | Dusting, Jonathan | Sherwood, Joseph M. | Balabani, Stavroula

Article Type: Research Article

Abstract: The effect of erythrocyte aggregation on blood viscosity and microcirculatory flow is a poorly understood area of haemodynamics, especially with relevance to serious pathological conditions. Advances in microfluidics have made it possible to study the details of blood flow in the microscale, however, important issues such as the relationship between the local microstructure and local flow characteristics have not been investigated extensively. In the present study an experimental system involving simple brightfield microscopy has been successfully developed for simultaneous, time-resolved quantification of velocity fields and local aggregation of human red blood cells (RBC) in microchannels. RBCs were suspended in Dextran …and phosphate buffer saline solutions for the control of aggregation. Local aggregation characteristics were investigated at bulk and local levels using statistical and edge-detection image processing techniques. A special case of aggregating flow in a microchannel, in which hematocrit gradients were present, was studied as a function of flowrate and time. The level of aggregation was found to strongly correlate with local variations in velocity in both the bulk flow and wall regions. The edge detection based analysis showed that near the side wall large aggregates are associated with regions corresponding to high local velocities and low local shear. On the contrary, in the bulk flow region large aggregates occurred in regions of low velocity and high erythrocyte concentration suggesting a combined effect of hematocrit and velocity distributions on local aggregation characteristics. The results of this study showed that using multiple methods for aggregation quantification, albeit empirical, could help towards a robust characterisation of the structural properties of the fluid. Show more

Keywords: Blood flow, cell aggregation, micro-PIV, image processing techniques

DOI: 10.3233/CH-151980

Citation: Clinical Hemorheology and Microcirculation, vol. 63, no. 2, pp. 123-148, 2016

Authors: Ballas, Samir K. | Connes, Philippe

Article Type: Research Article

Abstract: Red blood cell rheology and adhesiveness play a key role in the occurrence of vaso-occlusive like events in sickle cell anemia. The present paper reviews counter-intuitive findings supporting that rigid and serrated sickle red blood cells do not initiate vaso-occlusion. Instead, the less rigid red blood cells could initiate vaso-occlusion because of their increased adhesiveness to the vascular wall. We suspect that stiffness of sickle erythrocytes and the topography of RBC membrane are factors affecting adhesion to the endothelium.

Keywords: Sickle, topography, serrated sickle

DOI: 10.3233/CH-152014

Citation: Clinical Hemorheology and Microcirculation, vol. 63, no. 2, pp. 149-152, 2016

Authors: Pistulli, Rudin | Quitter, Felix | Andreas, Elise | Rohm, Ilonka | Kretzschmar, Daniel | Figulla, Hans-R. | Yilmaz, Atilla | Jung, Christian

Article Type: Research Article

Abstract: AIMS: Experimental autoimmune myocarditis (EAM) is a widely used murine model, in which cellular myocardial infiltration resembles human viral myocarditis. Although myocarditis can be readily assessed on histology, heart failure has not been fully characterized, as there are limitations in available markers and difficulties in hemodynamic measurements, especially on small rodents. We investigated whether intravital microscopy of the microcirculation can be used to characterize heart failure in EAM. METHODS: BALB/c mice (n  = 10 versus n  = 5 controls) were immunized with alpha myosin heavy chain peptide and myocarditis was confirmed on hematoxylin-eosin (HE) histology on day 21. Echocardiography …assessment included ejection fraction (EF), fractional shortening (FS), mitral valve doppler, left-ventricular end-diastolic diameter (LVEDd) and diastolic intra-ventricular septum thickness (IVSd). Microcirculatory analysis was performed using a sidestream dark field (SDF) microcirculation camera. The proportion of perfused vessels (PPV) and perfused vessel density (PVD) were recorded on the intestinal mucosa of the anaesthesized mice. RESULTS: Immunized mice developed EAM with typical cellular infiltration (p  < 0.003), left-ventricular hypertrophy (IVSd, p  = 0.027) and diastolic dysfunction (E/A, p  = 0.028) without significant EF reduction (p  = 0.845) or LV dilation (p  = 0.854). SDF recording consisted mainly of venules, as capillaries were too small. PPV and PVD were significantly increased in EAM mice (p 0.001 and 0.01 respectively) and correlated significantly with the histological myocarditis severity score (r  = 0.557, p  = 0.03 and r  = 0.57, p  = 0.025 respectively), whereas PPV but not PVD correlated with IVSd (r  = 0.588, p  = 0.02) and E/A ratio (r  = 0.703, p  = 0.003). CONCLUSIONS: Intravital microscopy can be used to characterize post-capillary intestinal perfusion of EAM mice. Thus we show a congestion of intestinal venules in EAM which correlates to the severity of myocarditis. Show more

Keywords: Myocarditis, heart failure, intravital microscopy, microcirculation

DOI: 10.3233/CH-152015

Citation: Clinical Hemorheology and Microcirculation, vol. 63, no. 2, pp. 153-162, 2016

Authors: Caimi, Gregorio | Presti, Rosalia Lo | Montana, Maria | Urso, Caterina | Canino, Baldassare | Hopps, Eugenia

Article Type: Research Article

Abstract: It is known that in OSAS the plasma lipid peroxidation has an opposite behavior in comparison with nitric oxide metabolites. In the re-examination of our survey of OSAS subjects we calculated the ratio between thiobarbituric acid reactive substances (TBARS) and nitric oxide metabolites (NOx) in relation to OSAS severity. The study has regarded 48 OSAS subjects subdivided in two subgroups according to the apnea/hypopnea index – AHI- (Low = 21 subjects with AHI <30 and High = 27 subjects with AHI >30). From the obtained data it is evident that the TBARS/NOx ratio is significantly higher in the H subgroup compared to L subgroup as well …as this ratio is reduced in L subgroup in comparison with the whole group of OSAS subjects. In the entire group of OSAS subjects the TBARS/NOx ratio results positively correlated with AHI and ODI and inversely correlated with mSO2 . Show more

Keywords: Lipid peroxidation, nitric oxide metabolites, obstructive sleep apnea syndrome

DOI: 10.3233/CH-152016

Citation: Clinical Hemorheology and Microcirculation, vol. 63, no. 2, pp. 163-168, 2016