SE2251071A1

SE2251071A1 - Method for preparing a homogeneous foam type contrast agent

Info

Publication number: SE2251071A1
Application number: SE2251071A
Authority: SE
Inventors: Ingvar Adnerhill; Lucia Casal-Dujat; Olof Böök; Thomas Fork; Wenyun Liu
Original assignee: Lument Ab
Priority date: 2022-09-15
Filing date: 2022-09-15
Publication date: 2024-03-16
Also published as: WO2024058699A1; CN118019576A

Abstract

A method for preparing a homogeneous foam type contrast agent (200) in a contrast agent mixer (100) comprising a mixer blade (120), a mixing container (110) and a controller (130), the method comprising:providing (S20) a dispersion made from a contrast powder (210) and a liquid (220),controlling (S30) the vertical distance (VD) between the mixing container (110) and the mixer blade (120), and controlling (S30) the rotational direction (RD) and rotational speed (RS) of the mixer blade (120) by means of the controller (130), thereby providing a substantially homogeneous foam type contrast agent (200),wherein the mixer blade (120) is rotated in two different rotational directions (RD).

Description

TECHNICAL FIELD The present invention relates to mixing method and more precisely to a method for preparing a homogeneous foam type contrast agent, as well as an associated contrast agent mixer.

BACKGROUND A computed tomography (CT) scan is a diagnostic imaging technique used to obtain detailed intemal images of a body. CT scanners norrnally use a rotating X-ray tube and a row of detectors placed in a gantry to measure X-ray attenuations by different tissues inside the body. The multiple X-ray measurements taken from different angles are then processed on a computer using tomographic reconstruction algorithms to produce tomographic, or cross-sectional, images of the body. CT scanning is known to be a versatile, fast and relatively cheap imaging technique compared to for instance magnetic resonance imaging.

In CT of the abdomen, contrast agents are used for demarcating structures by increasing differences in density between tissue compartments. The enhanced difference in contrast improves visualization of details necessary for the radiologist to detect and follow abnorrnalities within the abdomen over time and thus, with a possible medical diagnosis.

The patient on which the CT is to be performed is usually prepared with a per- oral agent for demarcating the gastro-intestinal tract. Up until now, the most commonly used demarcating agent has been a diluted solution of an iodine contrast medium meant for intravenous application, resulting in a white bowel content. Other agents are iso- osmotic solutions that exhibits bowel lumen in grey, close to the color of other body structures. Thus, positive oral f1lling agents provide no or unsatisfactory contrast between the bowel wall and the lumen of the small intestine on CT images. As a consequence, images of the bowel wall are less easy to read which may result in radiological diagnoses of reduced quality, including both false positive and negative diagnoses. Consequently, a negative, "black" filling, Contrast agent, with notably larger contrast against the mucosal lining and of the gut wall, was introduced in EP 3589331 thereby creating an opportunity for improved medical evaluation.

The contrast agent introduced in EP 3589331 is a ﬂuid, aqueous foam of microbubbles. The contrast agent is prepared manually using a kitchen immersion blender with or without a magnetic stirrer, from a contrast powder and a liquid to a completely homogeneous foam. In case visible bubbles are detected by bare eye at the surface of the foam, the bubbles are removed with a spoon or with a suction device such as a Pasteur pipette. If too many bubbles that may not be removed are present at the surface and/or in the bulk, the foam will have to be discarded or re-whipped increasing the preparation time and the cost of the product.

The process of preparing a contrast agent foam is labor and time consuming, relying on lengthy training to ensure reproducibility and foam quality for an optimized quality of the x-ray images.

Thus, from the above, it is understood that there is room for improvements of methods for providing a per-oral negative contrast agent foam.

SUMMARY An object of the present invention is to provide a new type of mixer which is improved over prior art and which addresses or at least mitigates the drawbacks discussed above. More specifically, an object of the invention is to provide a contrast agent mixer suitable for providing a per-oral negative contrast agent foam for e.g. abdominal computed tomography. These objects are addressed by the technique set forth in the appended independent claims with preferred embodiments defined in the dependent claims related thereto.

In an aspect, a method for preparing a homogeneous foam type contrast agent in a contrast agent mixer is provided. The contrast agent mixer comprises a mixer blade, a mixing container and a controller. The method comprises: providing a dispersion made from a contrast powder and a liquid; controlling the vertical distance between the mixing container and the mixer blade; and controlling the rotational direction and rotational speed of the mixer blade by means of the controller, thereby providing a substantially homogeneous foam type Contrast agent. In the method, the mixer blade is rotated in two different rotational directions. This is beneficial as it allows for the production of a homogeneous foam without enlarged bubbles or residue of the contrast powder.

In an embodiment, the step of providing a dispersion comprises mixing the contrast powder and the liquid with the mixer blade in the mixing container.

In an embodiment, the mixing container and the mixer blade is moved between two different vertical distances from each other.

In an embodiment, the mixer blade is rotated at two different rotational speeds.

In an embodiment, the step of controlling comprises: rotating the mixer blade with a first rotational speed at a first rotational direction, while the distance between the mixing container and the mixer blade is a first vertical distance, for a first period of time; shifting to a second rotational speed and rotating the mixer blade for a second period of time; shifting to a third rotational speed and moving the mixing container and the mixer blade relative each other between the first and a second vertical distance for a third period of time; shifting the rotational direction between a first and second rotational direction for a fourth period of time; and shifting to the first rotational speed and shifting the rotational direction between the first and second rotational direction for a fifth period of time. This is beneficial as it facilitates the release of bubbles formed under the mixer blade due to cavitation. Cavitation is undesirable because it may reduce efficiency, distort the ﬂow pattem, and result in a non-homogeneous foam. Overall, this allows for production of a homogeneous foam, without enlarged bubbles or residue of the contrast powder, in a time efficient manner.

In an embodiment the method further comprises controlling a horizontal distance between the mixing container and the mixer blade, and wherein the step of controlling comprises moving the mixing container and the mixer blade relative each other between the first and a second horizontal distance.

In an embodiment, the step of providing a dispersion further comprises dispensing the liquid into the mixing container by tilting a liquid container. This is beneficial as it allows for easy and correct liquid dispensing to the mixing container.

In an embodiment, the method further comprises moving the mixing container to a vertical position in which the mixing container is accessible to be removed from the contrast agent mixer.

In an embodiment, the mixing container comprises a ﬂat bottom surface. This is beneﬁcial as it reduces residue of the contrast powder.

In an embodiment, the radii ratio between the mixer blade and the bottom surface of the mixing container is in the range of 0.7 to 1.5, preferably around 0.8.

In an embodiment, the mixer blade is a homogeneous substantially circular mixer blade with a vertical thickness in the range of 0.8 mm to 1.8 mm. The circular shape is beneficial as it reduces the risk of turbulence in the mixing process and provides a foam with a more homogeneous bubble size. The thickness of the mixer blade affects the amount of air being mixed into the foam.

In an embodiment, a lower surface of the mixer blade comprises a bulge. This is beneficial as it provides enhanced turbulence during mixing which facilitates a more efficient mixing.

In an embodiment, the radii ratio between the mixer blade and mixing container body is in the range of 0.3 to 0.5, preferably around 0.4. This is beneficial as it enables the foam to comprise a predefined air content.

In an embodiment, the mixer blade has a diameter in the range of 35 mm to 60 mm, preferably 40 mm to 55 mm.

In an embodiment, the mixer blade is arranged on a mixer shaft, and the step of controlling the vertical position of the mixing container is carried out by a first electrical motor about a longitudinal axis of the mixer shaft. The step of controlling the rotational speed of the mixer blade is performed by a second electrical motor along the longitudinal axis of the mixer shaft, and the first electrical motor and the second electrical motor are controlled by the controller. This is beneficial as electrical motors provide a controllable torque, are energy efficient, silent, cost effective and comparably easy to control.

In an embodiment, the mixer blade is arranged on a mixer shaft such that an angle is formed between a plane of the mixer blade and a reference plane perpendicular to a longitudinal axis of the mixer shaft, and the angle is in the range of 0.5° to 5°, preferably in the range of 2° to 4°. This is beneficial as the blade angle can be used to control the amount of air incorporated in the foam and thereby the volume of the foam. The blade angle increases the effectiveness of the mixer blade.

In another aspect, a contrast agent mixer is provided. The mixer comprises a mixing container and mixer blade controlled by a controller of the contrast agent mixer. The controller is configured to cause control of the vertical distance of the mixing container, the rotational direction and the rotational speed of the mixer blade such that a contrast powder and a liquid is mixed in the mixing container, thereby providing a homogeneous foam type contrast agent.

In an embodiment, the contrast agent mixer is configured to cause execution of the method as described above. This is beneficial as it provides a foam especially suitable for per-oral negative contrast agent foam for abdominal CT.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will be described in the following; references being made to the appended diagrammatical drawings which illustrate non-limiting examples of how the inventive concept can be reduced into practice.

Fig. l is a ﬂow chart of a method according to embodiments of the present invention.

Fig. 2a, 2b, 3, 4a and 4b are side views of a mixer according to embodiments of the present invention.

Fig. 5 is a schematic block view of a mixer according to embodiments of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS The present application relates to a contrast agent mixer and a method providing a per-oral negative contrast agent foam. The foam is provided by dispersing a powder in a liquid and thereby providing a dispersion. The dispersion is then mixed incorporating air into the dispersion forrning a homogeneous foam. Providing a foam when starting with a liquid and a powder greatly reduces preparation time of the contrast agent. The mixer allows for provisioning of a homogeneous foam the starting components are a liquid and a powder, this is quite different from other mixers used for e. g. preparation of food products etc. Although the terrn "contrast powder" is used throughout this application, the powder does not need to have Contrast enhancíng properties itself. The terrn "contrast powder" refers to powder used for providing a contrast agent, or in other words, a contrast agent in powder forrn. As further elaborated below, the contrast powder may have stabilizing properties for a foam, wherein the air bubbles of the foam are contrast enhancing, and the contrast powder may hence be described as contrastfacílítatíng.

Starting in Fig. 1, a schematic block view of a method for preparing a homogeneous foam type contrast agent 200 in a contrast agent mixer 100 is shown. The mixer comprises a mixer blade 120, a mixing container 110 and a controller 130.

The method comprises providing a dispersion S20. The provided dispersion is made from a contrast powder 210 and a liquid 220 that may have been simply added to one another, or to some extent mixed and/or made into a foam with an unspecified air content and homogeneity of air bubble distribution.

The step of mixing S22 the contrast powder 210 and the liquid 220 may be performed as part of the method, or performed in advance. The dispersion may be provided in a premixed state, and further mixed S22 in the method of the present invention.

The contrast powder 210 may be selected from food-based proteins. A food based contrast agent is particularly suitable for per-oral administration and therefor for abdominal imaging, such as abdominal CT imaging. The contrast powder 210 may comprise egg white protein.

The step of providing the dispersion S20 may comprise dispensing S21 the liquid into the mixing container 110 by tilting a liquid container 140, as shown in Fig. 3.

At this stage, the contrast powder 210 may already be present in the mixing container 110. The tilting of the liquid container 140 may be carried out manually or automatically. The duration of the dispensing S21 of the liquid may be 5-30 seconds, preferably 10-25 seconds. The liquid dispensing is preferably directed away from the wall of the mixing container 110 in order to facilitate the dispersion.

Turning back to Fig. 1, the method further comprises controlling S30 the Vertical distance VD between the mixing container 110 and the mixer blade 120, and controlling S30 the rotational direction RD and rotational speed RS of the mixer blade 120 by means of the controller 130. The mixer blade 120 is rotated in two different rotational directions RD, as shown in Figs. 2a and 2b, during this step. By this, a substantially homogeneous foam type contrast agent 200 is provided.

A foam where air is dispersed in aqueous media will provide negative density contrast values in the range of -1000 HU to 0 HU, depending on the proportion of dispersed air, and may thus be used as a negative contrast agent. Such a contrast agent is usable for MRI, ultrasound and CT. The foam should be stable in the gastrointestinal tract in order to provide essentially the same CT negative density contrast values throughout the gastrointestinal tract.

By the step of controlling S30 the mixer blade in a dispersion, provided as above S20, a stable, homogeneous foam is provided. As mentioned above, the contrast powder 210 of the present invention may comprise egg white protein which has been found to have exceptional functional properties on gelation and foam formation. Egg white protein, or egg albumen, is comprised by several globular proteins ovalbumin, ovotransferin, ovomucoid, ovomucin, lysozyme, globulin, avidin. Even though ovalbumin is one of the critical proteins, the combination of different proteins contained in egg albumen is advantageous in foaming and foam stability properties. A mixture of opposed charges and the formation of interrnolecular bonds improve the stabilization of food foams. The mixture may thus preferably comprise at least ovalbumin, ovomucin and ovoglobulin. In the dispersion, the surfactant, e. g. egg albumen, perrnits the formation of air bubbles and stabilization thereof, due to their amphiphilic nature. Albumen proteins tumed out to have exceptional functional properties on foam formation and gelation and here hence preferred. However, in order to enhance the stabilization of the dispersed air bubbles, a foam stabilizer, e.g. a hydrocolloid acting as foam stabilizer, such as natural gum should be present in the liquid composition.

The dispersion may be provided as a foam and already comprise air. In this case, the step of controlling S30 the mixer blade 120 will result in a more well-defined air content and homogeneous bubble distribution. The step of controlling S30 the mixer blade 120 may also be a way to introduce air to the dispersion.

Rotation of the mixer blade 120 may start 1-20 seconds, preferably 3-10 seconds, after the start of the liquid dispensing S21.

The mixer blade 120 may be rotated with at least two different rotational speeds RS, preferably three different rotational speeds RS. It is advantageous to shift between several rotational speeds RS as it facilitates the escape of bubbles formed under the mixer blade 120 due to cavitation, and increases bubble homogeneity.

In order to reduce the risk of buildup of large bubbles of air in the foam, it may be beneficial to pause the rotation of the mixer blade 120 for a period to allow any oversized bubbles to raise to a surface of the foam and collapse. This may be provided by stopping the rotation of the mixer blade 120 for a rest period.

The step of controlling S30 the mixer blade 120 may comprise rotating S31 the mixer blade 120 with a first rotational speed RS at a first rotational direction RD, while the distance between the mixing container 110 and the mixer blade 120 is a first vertical distance VD, for a first period of time. As an example, the first rotational speed RS may be 4500 rpm which is a good speed for dispersing the powder 210 in the liquid 220.

Further, the rotational speed RS may be shifted S32 to a second rotational speed RS and the mixer blade 120 may be rotated for a second period of time. The second rotational speed may as an example be 6000 rpm which is suitable to disperse also the powder 210 that may be stuck to the edge of the bottom of the mixing container 1 10.

Further, the rotational speed RS may be shifted S33 to a third rotational speed RS and the mixing container 110 and the mixer blade 120 may be moved relative each other between the first and second vertical distance for a third period of time, as illustrated in Fig. 3 respective Fig. 4a. As an example, the third rotational speed RS may be 9000 rpm in order to reach a targeted air content. The mixing container 110 and the mixer blade 120 may be moved relative each other between the first and second vertical distance several times in order to increase bubble homogeneity.

The rotational direction RD may be shifted S34 between a first and second rotational direction RD, as illustrated in Figs. 2a and 2b, for a fourth period of time. By shifting S34 the rotational direction RD, issues related to cavitation is reduced. Cavitation is a phenomenon in which the static pressure of a liquid reduces to below the liquid's vapor pressure, leading to the forrnation of small vapor-filled cavities, or bubbles, in the liquid. This phenomenon typically happens under mixer blades, propellers, or similar components. The step of shifting S34 also ensures that forrnation of large bubbles is avoided, and facilitates size homogeneity of air bubbles in the contrast agent 200.

Further, the step of controlling S30 may comprise shifting S35 to the first rotational speed RS and shifting the rotational direction RD between the first and second rotational direction RD for a fifth period of time. If the first speed is 4500 rpm as in the example above, it is fast enough to stir the dispersion even at the bottom of the mixing container 110, and slow enough to release bubbles from the mixer blade 120.

Altematively or additionally, the step of controlling S30 may comprise moving S36 the mixing container 110 and the mixer blade (120) relative each other between a first and a second horizontal distance HD. If the vertical distance VD is defined in a z- direction, the horizontal distance HD may be defined in an xy-plane. Horizontal movement may replace vertical movement in a step of the method, or it may be performed additionally. By shifting the horizontal distance HD, better homogeneity of the air bubbles may be achieved.

As mentioned above, the mixing container 110 and the mixer blade 120 may be moved between two different vertical distances VD, such as the first and second vertical distance VD, from each other. The mixing container 110 may further be moved S40 to a vertical position VP, as shown in Fig. 4b, in which the mixing container 110 is accessible to be removed from the contrast agent mixer 100.

Tuming now to Fig. 5, a schematic block view of a contrast agent mixer 100 according to an embodiment is shown. The mixer 100 comprises a mixing container 110 and mixer blade 120 controlled by a controller 130 of the contrast agent mixer 100. The controller 130 is configured to cause control of the vertical distance VD of the mixing container, the rotational direction RD and the rotational speed RS of the mixer blade 120 such that a contrast powder 210 and a liquid 220 is mixed in the mixing container 110, thereby providing a homogeneous foam type contrast agent 200.

The mixer blade 120 of the mixer 100 may be arranged on a mixer shaft 122, and the step of controlling S30 the Vertical position VP of the mixing container 110 may be carried out by a first electrical motor 131 about a longitudinal axis of the mixer shaft 122. The step of controlling S30 the rotational speed RS of the mixer blade 120 may be performed by a second electrical motor 132 along the longitudinal axis of the mixer shaft 122, and the first electrical motor 131 and the second electrical motor 132 may be controlled by the controller 130.

The radii ratio between the mixer blade 120 and the bottom surface 111 of the mixing container 110 may be in the range of 0.7 to 1.5, preferably around 0.8. As an example, the diameter of the mixer blade 120 may be in the range of 35 mm to 60 mm, preferably 40 mm to 55 mm, more preferably 48 mm, and the diameter of the bottom surface 111 may be 50-60 mm, preferably closer to 60 mm. The diameter of the mixing container body may however be wider, for instance 110-120 mm.

The mixer blade 110 may be a homogeneous substantially circular mixer blade 110 with a Vertical thickness in the range of 0.8 mm to 1.8 mm. The Vertical thickness of the mixer blade 110 is related to the amount of air that can be dispersed in the foam.

A lower surface of the mixer blade 110 may comprise a bulge, or a stud. The lower surface may be saucer shaped. This is beneficial as it facilitates more turbulence during operation of the mixer 100, which is adVantageous for mixing and foam formation.

The mixer blade 120 may be arranged on a mixer shaft 122 such that an angle is formed between a plane of the mixer blade 120 and a reference plane perpendicular to a longitudinal axis of the mixer shaft 122. The angle may be in the range of 0.5° to 5°, preferably in the range of 2° to 4°, more preferably 3°. A greater tilting angle of a large blade creates more Vibration during mixing and thus louder noise, which is not preferred.

The angle connecting the bottom and the wall of the mixing container is preferably not sharp, in order to prevent accumulation of powder 210 during operation of the mixer 100.

Although not illustrated, the contrast agent mixer 100 may comprise more than one mixer blade 120. The contrast agent mixer 100 may comprise more than one mixer ll shaft 122. The mixer blades 120 may be arranged on the same mixer shaft 122 or distributed among several mixer shafts 122. The method may comprise controlling S30 the vertical distance VD between the mixing container 110 and each mixer blade 120, and controlling S30 the rotational direction RD and rotational speed RS of each mixer blade 120. The controlling S30 of the mixer blades 120 may be synchronous or asynchronous.

Modifications and other variants of the described embodiments Will come to mind to one skilled in the art having benefit of the teachings presented in the foregoing description and associated drawings. Therefore, it is to be understood that the embodiments are not limited to the specific example embodiments described in this disclosure and that modif1cations and other variants are intended to be included Within the scope of this disclosure. For example, While embodiments of the invention have been described With reference to a negative oral contrast agent mixer With related methods, persons skilled in the art Will appreciate that the embodiments of the invention can equivalently be applied to mixing of other agents Where a homogenous and controlled foaming is desired. Furthermore, although specific terms may be employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. Therefore, a person skilled in the art Would recognize numerous variations to the described embodiments that Would still fall Within the scope of the appended claims. Furthermore, although individual features may be included in different claims or embodiments, these may possibly advantageously be combined, and the inclusion of different claims or embodiments does not imply that a combination of features is not feasible and/or advantageous. In addition, singular references do not exclude a plurality. Finally, reference signs in the claims are provided merely as a clarifying example and should not be construed as limiting the scope of the claims in any Way.

Claims

1. A method for preparing a homogeneous foam type Contrast agent (200) in a contrast agent mixer (100) comprising a mixer blade (120), a mixing container (110) and a controller (130), the method comprising: providing (S20) a dispersion made from a contrast powder (210) and a liquid (220), controlling (S30) the vertical distance (VD) between the mixing container (110) and the mixer blade (120), and controlling (S30) the rotational direction (RD) and rotational speed (RS) of the mixer blade (120) by means of the controller (130), thereby providing a substantially homogeneous foam type contrast agent (200), wherein the mixer blade (120) is rotated in two different rotational directions (RD).

2. The method of claim 1, wherein the step of providing a dispersion comprises mixing (S22) the contrast powder (210) and the liquid (220) with the mixer blade (120) in the mixing container (110).

3. The method of claim 1 or 2, wherein the mixing container (110) and the mixer blade (120) is moved between two different vertical distances (VD) from each other.

4. The method of any preceding claim, wherein the mixer blade (120) is rotated with at least two different rotational speeds (RS).

5. The method of any preceding claim, wherein the step of controlling (S30) comprises: rotating (S31) the mixer blade (120) with a first rotational speed (RS) at a first rotational direction (RD), while the distance between the mixing container (110) and the mixer blade (120) is a first vertical distance (VD), for a first period of time, shifting (S32) to a second rotational speed (RS) and rotating the mixer blade (120) for a second period of time,shifting (S33) to a third rotational speed (RS) and moving the mixing container (110) and the mixer blade (120) relative each other between the first and a second vertical distance (VD) for a third period of time, shifting (S34) the rotational direction (RD) between a first and second rotational direction (RD) for a fourth period of time, shifting (S35) to the first rotational speed (RS) and shifting the rotational direction (RD) between the first and second rotational direction (RD) for a f1fth period of time.

6. The method of any preceding claim, further comprising controlling a horizontal distance (HD) between the mixing container (110) and the mixer blade (120), and wherein the step of controlling (S30) comprises moving (S36) the mixing container (110) and the mixer blade (120) relative each other between a first and a second horizontal distance (HD).

7. The method of any preceding claim, wherein the step of providing a dispersion (S20) further comprises dispensing (S21) the liquid (220) into the mixing container (110) by tilting a liquid container (140).

8. The method of any preceding claim, further comprising moving (S40) the mixing container (110) to a vertical position (VP) in which the mixing container (110) is accessible to be removed from the contrast agent mixer (100).

9. The method of any preceding claim, wherein the radii ratio between the mixer blade (120) and a bottom surface (111) of the mixing container (110) is in the range of 0.7 to 1.5, preferably around 0.

10. The method of any preceding claim, wherein the mixer blade (110) is a homogeneous substantially circular mixer blade (110) with a vertical thickness in the range of 0.8 mm to 1.8 mm.

11. The method of any preceding claim, Wherein a lower surface of the mixer blade (110) comprises a bulge.

12. The method of any preceding claim, Wherein the radii ratio between the mixer blade (120) and the body of the mixing container (110) is in the range of 0.3 to 0.5, preferably around 0.

13. The method of any preceding claim, Wherein the mixer blade (120) is arranged on a mixer shaft (122), and Wherein the step of controlling (S30) the Vertical position (VP) of the mixing container (110) is carried out by a first electrical motor (131) about a longitudinal axis of the mixer shaft (122), Wherein the step of controlling (S30) the rotational speed (RS) of the mixer blade (120) is performed by a second electrical motor (132) along the longitudinal axis of the mixer shaft (122), and Wherein the first electrical motor (131) and the second electrical motor (132) are controlled by the controller (130).

14. The method of any preceding claims, Wherein the mixer blade (120) is arranged on a mixer shaft (122) such that an angle is formed between a plane of the mixer blade (120) and a reference plane perpendicular to a longitudinal axis of the mixer shaft (122), Wherein the angle is in the range of 0.5° to 5°, preferably in the range of2° to 4°.

15. A contrast agent mixer (100) comprising a mixing container (110) and mixer blade (120) controlled by a controller (130) of the contrast agent mixer (100), Wherein the controller (130) is configured to cause control of the Vertical distance (VD) of the mixing container, the rotational direction (RD) and the rotational speed (RS) of the mixer blade (120) such that a contrast poWder (210) and a liquid (220) is mixed in the mixing container (110), thereby providing a homogeneous foam type contrast agent (200).

16. The Contrast agent mixer (100) of c1ain1 15 being conﬁgured to cause execution of the method according to any one of c1ain1s 1 to 14.