Paediatric Cerebral Arteriovenous Malformations: Value of Colour Doppler Ultrasound in the Diagnosis and Management of Endovascular Treatment

Colour Doppler ultrasound is a new diagnostic method in neuroradiology allowing the non invasive imaging of parenchymal and vascular structures in adults as in children through the intact skull. In particular, this study describes the use of colour Doppler US in children with intracranial arteriovenous malformations to determine its value in the evaluation of haemodynamic changes in cerebral vessels. To test the hypothesis that colour Doppler US analysis of spectral waveforms can be considered an indirect measurement of volume flow in major arteries and veins, we performed 13 colour Doppler US examinations on 4 children with vein of Galen malformations, 2 with parenchymal arteriovenous malformations and 7 children with facial angiomas, before the endovascular treatment, immediately thereafter and after a short time. Peak systolic and end-diastolic flow velocities, resistive index and pulsatility index, quantitative expression of cerebral blood flow, was attempted, while qualitative parameters such as blood flow direction, spectral waveform morphology and spectral broadening were not considered useful in the study. Colour Doppler US performed after endovascular treatment showed: a decrease of main feeder flow velocity and an increased pulsatility index and/or resistive index (as indirect measurement of increased peripheral stream resistance); the presence of echogenic foci within blood vessels, in the nidus or in the vein of Galen, representing embolisation materials or thrombi, such as residual color flow in the same embolised vascular territories; decreased blood flow velocity and spectral broadening in draining veins, indicating an incomplete occlusion of fistulas. In one case of vein of Galen malformation, we performed colour Doppler US three days after the embolisation, showing the occlusion by thrombi of the vein of Galen and of the draining veins. Colour Doppler US can be considered a valuable method for non-invasive haemodynamic assessment of blood flow in cerebral arteriovenous malformations. With this procedure, allowing serial examinations with unlimited repeatability and by using portable equipment at the patient' bedside, it is possible to monitor haemodynamic changes after embolisation. This limits the use of more invasive procedures such as CT, MR and angiography and the relatively large amounts of contrast material and radiation dose.

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Comparative study of colour Doppler vs. FNNAC findings in WHO grade II thyroid enlargement in adult females

International Journal of Otorhinolaryngology and Head and Neck Surgery ◽

10.18203/issn.2454-5929.ijohns20192724 ◽

2019 ◽

Vol 5 (4) ◽

pp. 1025

Author(s):

Sudhakar Rao M. S. ◽

Navneeth T. P. ◽

John C. J.

Keyword(s):

Pulsatility Index ◽

Low Cost ◽

Resistive Index ◽

Colour Doppler ◽

Who Grade ◽

Predictive Values ◽

Non Invasive ◽

Adult Females ◽

The Mean ◽

Sensitivity Specificity

Background: Thyroid gland disorders form one of the most common endocrinal and surgical problems encountered in clinical practice. FNNAC is widely accepted as the primary and better method than FNAC for investigation but has its disadvantages. Colour Doppler is a non-invasive, low cost, easily available and repeatable investigation with least patient discomfort and can be valuable in detection of benign and malignant thyroid enlargements.Methods: Forty cases of adult females with WHO grade 2 thyroid enlargement attending the department of otorhinolaryngology selected on simple random basis were included in this study. Following written consent, Colour Doppler scanning and FNNAC test were done on the thyroid swelling and the results were analysed. Results: The mean age of patients was 32.44 years. The mean age of malignancy was 44.66 years and showed statistically significant association. The Resistive and Pulsatility index and combination of both were found to have statistically significant results in detecting malignant and benign lesions The sensitivity, specificity, positive and negative predictive values of RI and PI were 83.33%, 94.12%, 71.43%, 96.97% and 50%, 94.12%, 60% and 91.43% respectively. On combining both the indices, the sensitivity was 91.67% and the positive predictive value was 97.06%.Conclusions: Colour Doppler can differentiate between benign and malignant thyroid enlargements using Resistive index (of>0.75) and Pulsatility Index (of>1.5) and can be a complementary diagnostic tool in the thyroid enlargement lesions, considering its accuracy, cost-effectiveness, easy availability and non-invasive repeatable nature.

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Cerebral Arteriovenous Malformations with Associated Arterial Aneurysms: Hemodynamic and Therapeutic Considerations

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques ◽

10.1017/s0317167100027487 ◽

1988 ◽

Vol 15 (2) ◽

pp. 130-134 ◽

Cited By ~ 55

Author(s):

Douglas Kondziolka ◽

Bruce J. Nixon ◽

Pierre Lasjaunias ◽

William S. Tucker ◽

...

Keyword(s):

Blood Flow ◽

Arteriovenous Malformation ◽

Endovascular Treatment ◽

Arteriovenous Malformations ◽

Local Blood Flow ◽

Cerebral Arteriovenous Malformations ◽

Regional Hemodynamics ◽

The Common ◽

Arterial Aneurysms ◽

Therapeutic Considerations

ABSTRACT:The common vascular anomalies of cerebral aneurysm and arteriovenous malformation may exist independently, or together as part of a closely related hemodynamic pairing. Resection or embolization of an AVM may be followed by a decrease in local blood flow, and lead to regression of a suitably situated proximal aneurysm. However, aneurysms located outside the angioarchitecture of the AVM, which remain flow-unrelated to the malformation, will likely not regress, and may in fact enlarge. Two cases are presented which demonstrate these vascular relationships, in order to better understand the regional hemodynamics of these anomalies prior to surgical or endovascular treatment planning.

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Cerebral arteriovenous malformations: features of the functioning of the blood circulation system after endovascular treatment with long-term monitoring

Endovascular Neuroradiology ◽

10.26683/2304-9359-2020-3(33)-19-28 ◽

2020 ◽

Vol 33 (3) ◽

pp. 19-28

Author(s):

S.V. Chebanyuk ◽

O.E. Svyrydyuk ◽

O.F. Sydorenko ◽

M.Yu. Mamonova

Keyword(s):

Computed Tomography ◽

Blood Flow ◽

Cerebral Blood Flow ◽

Endovascular Treatment ◽

Postoperative Period ◽

Arteriovenous Malformations ◽

Circulatory System ◽

Early Postoperative Period ◽

Dynamic Observation

Objective ‒ to determine the features of the functioning of the circulatory system in patients with arteriovenous malformations (AVM) of the brain after endovascular operations with long-term observation.Materials and methods. 479 patients with cerebral AVM were examined and treated, of which 377 (78.7 %) were men and 102 (21.3 %) were women. The average age of patients was (27.5±3.5) years. Patients aged 18‒30 years predominated (75.4 %). A dynamic observation of 347 patients after endovascular treatment after 3, 6, 12 and 24 months and more was carried out. Patients underwent cerebral angiography, computed tomography, magnetic resonance imaging, single-photon emission computed tomography, echocardiography, Doppler cardiography, electrocardiography, duplex scanning of cerebral vessels.Results. The study shows the effect of arteriovenous shunting on cerebral and systemic hemodynamics in general. Switching off AVM from the cerebral blood flow improved cerebral hemodynamics already in the early postoperative period, the changes were more significant after 3‒6 months of observation and in some cases reached values in healthy individuals 2 years after the operation. In 52.8 % of patients with AVM, systemic circulation disorders occurred due to an increase in heart rate, minute and stroke blood volumes, left ventricular ejection fraction with an increase in mechanical load on the heart, which led to changes in systolic contraction and diastolic relaxation of the left ventricle of the heart with the development of heart failure. Switching off the AVM from the cerebral blood flow did not cause significant changes in heart functions in the early postoperative period; positive changes occurred over a long period. Dynamic observation showed a positive restructuring of the functioning of the circulatory system in patients after endovascular exclusion of the malformation.Conclusions. Arteriovenous malformations are hemodynamically active systems that lead to hemodynamic-perfusion changes, both at the local and at the general hemodynamic level. The exclusion of the malformation from the bloodstream contributes to the regression of disorders of cerebral and intracardiac blood flow caused by the anatomical and functional characteristics of the malformation itself and its clinical course.

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The effect of moderate treadmill exercise on the resistive index of the medial long posterior ciliary artery in dogs

Veterinární Medicína ◽

10.17221/162/2018-vetmed ◽

2019 ◽

Vol 64 (No. 9) ◽

pp. 400-406

Author(s):

M Pugliese ◽

M Ragusa ◽

V Biondi ◽

A Passantino ◽

K Zhang ◽

...

Keyword(s):

Blood Flow ◽

Physical Exercise ◽

Rank Correlation ◽

Resistive Index ◽

Recovery Phase ◽

Indirect Measurement ◽

Applanation Tonometry ◽

Passive Recovery ◽

Posterior Ciliary Artery ◽

Ciliary Artery

The resistive index (RI) is an indirect measurement of arterial resistance by means of a ratio between the peak systolic and end diastolic velocities recorded with a spectral Doppler device, especially used to evaluate the vascular damage in ocular diseases such as glaucoma. Some ocular variables such as the intraocular pressure (IOP), the choroidal thickness, the axial length and the ocular blood flow may be influenced by physical exercise. The purpose of this study was to evaluate the influence of the exercise on the RI of the medial long posterior ciliary artery in dogs, and correlate the data obtained with the IOP values. Ten clinically healthy dogs were subjected to moderate physical exercise on a canine motorised treadmill at different speeds for 45 minutes. A colour Doppler examination was performed and the RI values were calculated for the medial long posterior ciliary artery at rest, immediately after the exercise, and after 60 minutes at the end of the exercise. At the same times, the IOP was recorded by applanation tonometry. The data were analysed by a two-way repeated ANOVA measurement in order to compare the RI and the IOP. Wilcoxon’s test was applied for the post hoc comparison. Spearman’s rank correlation for non-normal distribution was used to determine a relationship between the RI and the IOP. The at rest RI was 0.722 +/–0.022, IOP 12.38 +/3.21 mm Hg. A significant decrease in the RI was observed immediately after the exercise (0.697 +/–0.035) and during the passive recovery phase (0.682 +/–0.042). A significant decrease in the IOP (11+/3.39 mmHg) was recorded after 60 min of the passive recovery phase; at the end of the exercise, a slight decrease (12.29+/4.26 mm Hg) mm Hg was detected. During the test, a linear correlation between the RI and the IOP was observed. Our results suggest that exercise induces the modification of the ophthalmic blood flow in dogs, presumably related to the compensatory neuro-hormonal mechanisms.

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Non-invasive measurement techniques for quantitative assessment of optic nerve head blood flow

European Journal of Ophthalmology ◽

10.1177/1120672119858891 ◽

2019 ◽

Vol 30 (2) ◽

pp. 235-244 ◽

Cited By ~ 2

Author(s):

Fia Vosborg ◽

Lasse Malmqvist ◽

Steffen Hamann

Keyword(s):

Blood Flow ◽

Optic Nerve ◽

Optic Nerve Head ◽

Optical Coherence Tomography Angiography ◽

Laser Speckle ◽

Doppler Imaging ◽

Laser Speckle Flowgraphy ◽

Colour Doppler ◽

Non Invasive ◽

Colour Doppler Imaging

Diseases of the optic nerve head involving changes in blood flow are common. However, the pathophysiology is not always fully understood. Several non-invasive methods for measuring optic nerve head blood flow are available, but currently no gold standard has been established. Methods for measuring blood flow in optic neuropathies including colour Doppler imaging, retinal function imager, optical coherence tomography angiography and laser speckle flowgraphy are reviewed. Ultrasound colour Doppler imaging is a fast measurement technique where several different parameters, especially the blood flow velocity, can be calculated. Though used for many years in ophthalmology, its use is not standardized and it requires significant observer skills. The retinal function imager is a direct method where the haemoglobin in erythrocytes is visualized and blood flow velocities in retinal vessels are calculated from a series of photos. The technique is not suitable for direct measurement of blood flow within the optic nerve head. Laser speckle flowgraphy uses a laser light which creates a light scatter pattern in the tissue. Particles moving in the area causes changes in the speckle pattern from which a relative blood flow can be estimated. It is, however, not known whether optic nerve head microcirculation is measurable with the technique. Optical coherence tomography angiography uses multiple scans to evaluate blood flow with good reproducibility but often problems with artefacts. The technique is continuously being refined and increasingly used in research as a tool for the study of blood flow in retinopathies and optic neuropathies. Most of the conducted studies are based on small sample sizes, but some of the methods show promising results in an optic nerve head blood flow research setting. Further and larger studies are required to provide standardized and comparable measurements before one or more of the methods can be considered clinical helpful in daily practice.

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