Suboptimal Contrast Opacification of Dynamic Head and Neck MR Angiography due to Venous Stasis and Reflux: Technical Considerations for Optimization

Hingwala, Divyata Rajendra; Kesavadas, Chandrasekharan; Kapilamoorthy, Tirur Raman

doi:10.3174/ajnr.a2301

Cited by 10 publications

(3 citation statements)

References 13 publications

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“…Vascular contrast results from the T1-shortening effects of gadolinium on adjacent water protons and has relatively little dependence on inflow effects. In contrast to MRA, the limitation of CE MRV is that maximal contrast enhancement achieved in veins is typically lower than arteries because the contrast bolus is more dilute by the time it reaches the venous system [126]. To improve background suppression and emphasize vascular signal, fat saturation can be added to a 3D spoiled gradient-echo sequence with a small increase in acquisition time.…”

Section: Noninvasive Imaging Modalitiesmentioning

confidence: 99%

The role of noninvasive and invasive diagnostic imaging techniques for detection of extra-cranial venous system anomalies and developmental variants

Dolić

Siddiqui

Karmon

et al. 2013

BMC Med

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The extra-cranial venous system is complex and not well studied in comparison to the peripheral venous system. A newly proposed vascular condition, named chronic cerebrospinal venous insufficiency (CCSVI), described initially in patients with multiple sclerosis (MS) has triggered intense interest in better understanding of the role of extra-cranial venous anomalies and developmental variants. So far, there is no established diagnostic imaging modality, non-invasive or invasive, that can serve as the “gold standard” for detection of these venous anomalies. However, consensus guidelines and standardized imaging protocols are emerging. Most likely, a multimodal imaging approach will ultimately be the most comprehensive means for screening, diagnostic and monitoring purposes. Further research is needed to determine the spectrum of extra-cranial venous pathology and to compare the imaging findings with pathological examinations. The ability to define and reliably detect noninvasively these anomalies is an essential step toward establishing their incidence and prevalence. The role for these anomalies in causing significant hemodynamic consequences for the intra-cranial venous drainage in MS patients and other neurologic disorders, and in aging, remains unproven.

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Section: Noninvasive Imaging Modalitiesmentioning

confidence: 99%

The role of noninvasive and invasive diagnostic imaging techniques for detection of extra-cranial venous system anomalies and developmental variants

Dolić

Siddiqui

Karmon

et al. 2013

BMC Med

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“…Despite the vast amount of literature that has been accumulated on X‐ray angiography over the past 95 years, to our knowledge, little‐to‐nothing has been done to understand the hemodynamics underlying contrast reflux. In general, reflux has only been viewed as an excess of contrast volume that does not contribute to, or even degrades, image quality by contrast density artifacts and delayed time of arrival of contrast to the region of interest 1–3 . Power injection systems and contrast volume monitors have been developed to reduce the excess of contrast that refluxes instead of filling the vascular region of interest, with the intention of reducing contrast‐induced acute kidney injury in patients 4–6 .…”

Section: Introductionmentioning

confidence: 99%

“…In general, reflux has only been viewed as an excess of contrast volume that does not contribute to, or even degrades, image quality by contrast density artifacts and delayed time of arrival of contrast to the region of interest. [1][2][3] Power injection systems and contrast volume monitors have been developed to reduce the excess of contrast that refluxes instead of filling the vascular region of interest, with the intention of reducing contrast-induced acute kidney injury in patients. [4][5][6] The extent of contrast reflux (usually graded by a semiquantitative score) 7 has been used as an indication of disease severity because the disease results in altered hemodynamics that are observed as reflux.…”

Section: Introductionmentioning

confidence: 99%

A novel angiographic method to estimate arterial blood flow rates using contrast reflux: Effect of injection parameters

et al. 2022

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Background Contrast reflux, which is the retrograde movement of contrast against flow direction, is commonly observed during angiography. Despite a vast body of literature on angiography, the hemodynamic factors affecting contrast reflux have not been studied. Numerous methods have been developed to extract flow from angiography, but the reliability of these methods is not yet sufficient to be of routine clinical use. Purpose To evaluate the effect of baseline blood flow rates and injection conditions on the extent of contrast reflux. To estimate arterial flow rates based on measurement of contrast reflux length. Materials and methods Iodinated contrast was injected into an idealized tube as well as a physiologically accurate model of the cervico‐cerebral vasculature. A total of 194 high‐speed angiograms were acquired under varying “blood” flow rates and injection conditions (catheter size, injection rate, and injection time). The length of contrast reflux was compared to the input variables and to dimensionless fluid dynamics parameters at the catheter‐tip. Arterial blood flow rates were estimated using contrast reflux length as well as a traditional transit‐time method and compared to measured flow rates. Results Contrast reflux lengths were significantly affected by contrast injection rate (p < 0.0001), baseline blood flow rate (p = 0.0004), and catheter size (p = 0.04), but not by contrast injection time (p = 0.4). Reflux lengths were found to be correlated to dimensionless fluid dynamics parameters by an exponential function (R2 = 0.6–0.99). When considering the entire dataset in unison, flow estimation errors with the reflux‐length method (39% ± 33%) were significantly higher (p = 0.003) than the transit‐time method (33% ± 36%). However, when subgrouped by catheter, the error with the reflux‐length method was substantially reduced and was significantly lower (14% ± 14%, p < 0.0001) than the transit‐time method. Conclusion Results show correlations between contrast reflux length and baseline hemodynamic parameters that have not been reported previously. Clinically relevant blood flow rate estimation is feasible by simple measurement of reflux length. In vivo and clinical studies are required to confirm these correlations and to refine the methodology of estimating blood flow by reflux.

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The Role of Diagnostic Imaging Techniques for Detection of Extracranial Venous System Abnormalities Associated with Central Nervous System Disorders

Dolić¹,

Zivadinov²

2016

Neurovascular Imaging

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Suboptimal Contrast Opacification of Dynamic Head and Neck MR Angiography due to Venous Stasis and Reflux: Technical Considerations for Optimization

Abstract: BACKGROUND AND PURPOSE: Contrast-enhanced head and neck MRA may be degraded by venous stasis and reflux of contrast into the jugular veins. The purpose of this study was to evaluate the relationship between venous stasis and reflux and the side of injection and other causal factors.

Cited by 10 publications

References 13 publications

The role of noninvasive and invasive diagnostic imaging techniques for detection of extra-cranial venous system anomalies and developmental variants

The role of noninvasive and invasive diagnostic imaging techniques for detection of extra-cranial venous system anomalies and developmental variants

A novel angiographic method to estimate arterial blood flow rates using contrast reflux: Effect of injection parameters

The Role of Diagnostic Imaging Techniques for Detection of Extracranial Venous System Abnormalities Associated with Central Nervous System Disorders

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