No abstract available

[en] In this paper the method of microcirculatory blood flow velocity registration is considered. The proposed method is based on speckle pattern analysis. The measuring setup of blood flow velocity is presented. Using this setup, blood flow velocity of a group of people under various conditions has been studied and the results of these studies are presented. (paper)

[en] Highlights: • CT perfusion can predict response to TACE within one day after treatment. • This response is sustained during long-term follow up. • Treatment related decisions, e.g. retreatment, can now be made within one day of therapy. - Abstract: Purpose: To determine the value of CT perfusion (CTP) for early response assessment after transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC). Materials and methods: Between April 2013 and April 2015, 41 HCC (16 patients) were included in this study. CT perfusion was performed before and one day after TACE. Blood flow (BF), blood volume (BV), time to start (TTS), arterial liver perfusion (ALP), portal liver perfusion (PVP) and hepatic perfusion index (HPI) were measured. Quantitative perfusion values before and after TACE were compared to the response assessed using mRECIST criteria six weeks after TACE and long-term outcome was assessed. Results: Twenty-one lesions (51%) had complete remission (CR) and five (12%) had partial response (PR) six weeks after TACE. CTP parameters were significantly reduced after TACE in responders (PR, CR, p < 0.001) while no difference was observed in non-responders. ALP_post was superior in the prediction of CR compared to BF_post and BV_post (p < 0.001) with a sensitivity, specificity, PPV, NPV, and accuracy of 90%, 90%, 91%, 90%, and 91%, respectively. Only 3/21 lesions with CR recurred, with a mean local-recurrence-free survival of 19.6 months. Conclusion: CT perfusion detects lesions with complete response one day after TACE, and is a feasible tool for early response assessment.

[en] Some new methods of fast MRI-imaging, tissue-specific MRI-imaging, flow MRI-imaging and -quantification, most of them based on Multiecho imaging are discussed. (author). 33 refs.; 20 figs.; 1 tab

[en] Highlights: • Review of 28 studies from January 1996 to January 2017. • Some normal ranges of 2D and 3D fetal kidney size and volume available. • Limited research on fetal kidney growth in abnormal fetal growth. • Good reliability and reproducibility of 3D volumes has not yet been demonstrated. - Abstract: Purpose: To determine the role of ultrasound imaging in evaluating fetal kidney growth. Methods: MEDLINE, CINAHL and EMBASE databases were electronically searched for studies between 1996 and January 2017 and limited to English language. Studies were included if they reported on an ultrasound technique to assess fetal kidney growth and they were not a case report or case series. There was independent selection of studies by two reviewers in consensus with one other reviewer. Data were extracted by one reviewer in consensus with two other reviewers. Results: A total of 1785 articles were identified. The full text of 39 of these were assessed for eligibility for inclusion. Twenty-eight studies were then included in the review. Standard two dimensional (2D) fetal renal measurements are easy to perform, however, this review identified that most studies had some methodological limitations. The disadvantage with 2D and three dimensional (3D) fetal renal volumes are that they include the entire kidney and good reproducibility of 3D volumes has not yet been demonstrated. Currently there is limited research on fetal kidney growth in the setting of abnormal fetal growth. Research focussing directly on fetal kidney parenchyma and blood flow is scarce. Conclusions: Some nomograms of 2D and 3D fetal kidney size and volume have been developed. Kidney length is the most popular single fetal kidney measurement; however, it does not seem to be a good indicator of growth. In IUGR fetuses, kidney length remained similar to appropriately grown fetuses whereas AP and TS dimensions were significantly decreased. New ultrasound techniques focusing on the parenchyma of the kidney and perfusion to the kidney should be explored as they may provide more meaningful information on kidney development in the fetus and future kidney function.

No abstract available

[en] The role of cardiovascular magnetic resonance imaging in providing functional information of the heart is examined. 16 refs.; 3 figs

[en] Cine computed tomography is a relatively new research/diagnostic technique that allows for high speed (50 millisecond) images of the heart following injection of intravenous contrast media. Recent validation studies in dogs have demonstrated that global and regional left and right ventricular geometry and function can be accurately assessed with cine computed tomography. For example, left ventricular mass can be measured with an accuracy of ± 3-4 g, right ventricular stroke volumes ± 2-3 ml and aortic regurgitant volume ± 1-3 ml. Also, vein bypass patency can be defined with about 90% accuracy. Two approaches to estimating changes in myocardial blood flow are actively under investigation. Studies in animals indicate that changes in bypass graft flow reserve can be accurately measured with cine computed tomography. Furthermore, preliminary animal studies suggest that changes in left ventricular perfusion can also be defined with this technology. Thus, cine computed tomography promises to become an important research technique and a valuable clinical approach to the diagnostic evaluation of patients with cardiac disease. 9 refs.; 3 figs

[en] During each cardiac cycle pulsatile arterial blood inflates the vascular bed of the brain, forcing cerebrospinal fluid (CSF) and venous blood out of the cranium. Excessive arterial pulsatility may be part of a harmful mechanism causing cognitive decline among elderly. Additionally, restricted venous flow from the brain is suggested as the cause of multiple sclerosis. Addressing hypotheses derived from these observations requires accurate and reliable investigational methods. This work focused on assessing the pulsatile waveform of cerebral arterial, venous and CSF flows. The overall aim of this dissertation was to explore cerebral blood flow and intracranial pulsatility using MRI, with respect to measurement, physiological and pathophysiological aspects.Two-dimensional phase contrast magnetic resonance imaging (2D PCMRI) was used to assess the pulsatile waveforms of cerebral arterial, venous and CSF flow. The repeatability was assessed in healthy young subjects. The 2D PCMRI measurements of cerebral arterial, venous and CSF pulsatility were generally repeatable but the pulsatility decreased systematically during the investigation. A method combining 2D PCMRI measurements with invasive CSF infusion tests to determine the magnitude and distribution of compliance within the craniospinal system was developed and applied in a group of healthy elderly. The intracranial space contained approximately two thirds of the total craniospinal compliance. The magnitude of craniospinal compliance was less than suggested in previous studies. The vascular hypothesis for multiple sclerosis was tested. Venous drainage in the internal jugular veins was compared between healthy controls and multiple sclerosis patients using 2D PCMRI. For both groups, a great variability in the internal jugular flow was observed but no pattern specific to multiple sclerosis could be found. Relationships between regional brain volumes and potential biomarkers of intracranial cardiac-related pulsatile stress were assessed in healthy elderly. The biomarkers were extracted from invasive CSF pressure measurements as well as 2D PCMRI acquisitions. The volumes of temporal cortex, frontal cortex and hippocampus were negatively related to the magnitude of cardiac-related intracranial pulsatility. Finally, a potentially improved workflow to assess the volume of arterial pulsatility using time resolved, four-dimensional phase contrast MRI measurements (4D PCMRI) was evaluated. The measurements showed good agreement with 2D PCMRI acquisitions. In conclusion, this work showed that 2D PCMRI is a feasible tool to study the pulsatile waveforms of cerebral blood and CSF flow. Conventional views regarding the magnitude and distribution of craniospinal compliance was challenged, with important implications regarding the understanding of how intracranial vascular pulsatility is absorbed. A first counterpoint to previous near-uniform observations of obstructions in the internal jugular veins in multiple sclerosis was provided. It was demonstrated that large cardiac- related intracranial pulsatility were related to smaller volumes of brain regions that are important in neurodegenerative diseases among elderly. This represents a strong rationale to further investigate the role of excessive intracranial pulsatility in cognitive impairment and dementia. For that work, 4D PCMRI will facilitate an effective analysis of cerebral blood flow and pulsatility

[en] The purpose of this study was to evaluate the efficacy of transvaginal color Doppler sonography (TVCDS) in the diagnosis of retained placenta. 24 cases pathologically diagnosed retained placenta and underwent TVCDS before treatment were included in this study. The clinical findings, TVCDS findings, and pathological findings were reviewed retrospectively. We evaluated size, location, echo character, and myometrial invasion with gray scale. Presence, grade (1-3), location, peak systolic velocity (PSV), and resistive index (RI) of blood flow in retained placenta were observed. In transvaginal sonography, 21 cases had cystic changes and heterogeneous echo texture in retained placenta. The sizes of retained placenta were 1.4-6.4 cm (mean 3.4 cm ), and 17 cases demonstrated myometrial invasion. In TVCDS, 19 cases showed blood flow in retained placenta but 5 cases did not. Most blood flows were grade 2 and located in either periphery or both periphery and center of the mass. PSV were 15.4-99.3 cm/sec (mean 47.33 ± 22.75 cm/sec ) and RI were 0.17-0.43 (mean 0.31 ± 0.07). RI of blood flow inretained placenta negatively correlated with the size (p=0.033<0.05). Retained placenta demonstrated with TVCDS shows blood flow of high velocity and low impedance. TVCDS may be a useful tool in the diagnosis of retained placenta.