Radsci 360 Automatic Injection Devices

Front 1

Purpose of automatic injection device

Back 1

Injects contrast media under controlled conditions. Controls the pressure, amount injected and the flow rate. The goal is to match the flow rate of the blood in the vessel.

Front 2

Components of an injector

Back 2

1. Control Panel
2. Syringe assembly
3. Heating device
4. High-pressure mechanism

Front 3

Control Panel

Back 3

Used to set the parameters of the injection sequence. Each is supplied with an operating manual to refer to for assistance. May have manual or digital and remote controls.

Front 4

Syringe Assembly

Back 4

Removable and disposable, but some are reusable. Syringes come in a variety of sizes, ranging from 60 to 200 ml. The syringe must be handled with care b/c any abnormality can cause failure.

Front 5

Heating Device

Back 5

An electronic device that heats and maintains the contrast medium at or near body temperature and reduces the viscosity of certain contrast agents. Improves the flow rate, like "Mrs. Butterworth's." Should always use pre-warmed contrast media. This device is located in the injector near the syringe.

Front 6

Purpose of automatic injection device

Back 6

Injects contrast media under controlled conditions. Controls the pressure, amount injected and the flow rate. The goal is to match the flow rate of the blood in the vessel.

Front 7

Components of an injector

Back 7

1. Control Panel
2. Syringe assembly
3. Heating device
4. High-pressure mechanism

Front 8

Control Panel

Back 8

Used to set the parameters of the injection sequence. Each is supplied with an operating manual to refer to for assistance. May have manual or digital and remote controls.

Front 9

Syringe Assembly

Back 9

Removable and disposable, but some are reusable. Syringes come in a variety of sizes, ranging from 60 to 200 ml. The syringe must be handled with care b/c any abnormality can cause failure.

Front 10

Heating Device

Back 10

An electronic device that heats and maintains the contrast medium at or near body temperature (98 F) and reduces the viscosity of certain contrast agents. Improves the flow rate, like "Mrs. Butterworth's." Should always use pre-warmed contrast media. This device is located in the injector near the syringe.

Front 11

High Pressure Mechanism

Back 11

Electromechanical, motor driven device that pushes the plunger of the syringe to inject the contrast media. It is an electric drive motor connected to a jackscrew that drives the piston into or out of the syringe. A mechanical stop physically limits the injection volume to a preset amount.

Front 12

Optional components

Back 12

-ECG Triggering Device: allows injection through ECG triggering, where the entire injection can be triggered by the R wave (ventricular systole)
-Double Injector Head: can be attached to the table
-Double syringe assembly: allows pre-loading of two syringes to prevent time loss.

Front 13

Safety Devices

Back 13

-Acceleration regulators: in the motor, acceleration occurs over a specific amount of time to avoid catheter whip and vessel damage.
-Pressure limiting device: sets a max on the pressure permitted to be generated
-Volume limiting device: sets a max limit on the volume on CM injected
-Aiming device: head pointed to the floor to prevent injection of air bubbles.

Front 14

Flow Rate

Back 14

The amount of contrast delivered per unit of time. The flow rate chosen is governed by the type of procedure (location of the catheter), the vessel entered (size), the patient (physiological state) and the nature of the disease.

Front 15

Flow rate variables

Back 15

Flow rate is dependent on the viscosity of the contrast, the length and diameter of the catheter, the presence of side holes and the injection pressure.

Front 16

Catheter length

Back 16

Inversely proportional to flow rate. As the length increase, flow rate decreases. This is because the resistance is applied over a longer length of catheter tubing.

Front 17

Catheter diameter

Back 17

Directly proportional to flow rate. As the diameter increases, flow rate also increases. A larger internal diameter (lumen) provides less resistance against the flow of CM and requires less pressure to maintain a constant rate.

Front 18

Viscosity

Back 18

The thickness of the contrast media is inversely proportional to the flow rate. As viscosity increases, flow rate decreases.

Front 19

Catheter side holes

Back 19

The presence of side holes increase the flow rate. They increase the delivery rate by 10-20%. These also aid in catheter stability.

Front 20

Catheter Purpose

Back 20

Catheters serve as a pipeline through which contrast medium can be selectively introduced into a specific vessel.

Front 21

Advantages for using catheters

Back 21

1. Allows direct access to the vessel of interest
2. Less dilution occurs because the contrast does not have to travel through the blood
3. Allows use of a smaller bolus of contrast, making the exams safer.
4. Allows use of smaller amounts of contrast, making the exams more tolerable.
5. Ability to biopsy and measure pressures within the lumen of vessels or directly from the heart chambers.

Front 22

Types of catheter materials

Back 22

*Must be radiopaque without CM
1. Teflon
2. Polyethylene
3. Polyurethane

Front 23

Teflon catheters

Back 23

Has the lowest coefficient of friction, stiff
Good memory, retains shape
High material strength
Stiffer than other materials
Larger inner diameters
Higher potential to kink

Front 24

Polyethylene

Back 24

High tissue compatibility
Contains no additives
Soft and flexible
More flexible; better torque-twisting capability
*Better accommodates increase pressure with smaller wall thicknesses. i.e. safer b/c initial hole made in the vessel can be smaller

Front 25

Polyurethane

Back 25

High tissue compatibility
Increased lumen diameters
Ease of insertion and placement
Low incidence of tissue trauma
Holds shape better
*Better accommodates increased pressure with smaller wall thicknesses

Front 26

Catheter Size

Back 26

Catheter sizes are expressed in inches or millimeters or by French number.
1 in = 25.4 mm; this is used to indicate the inside diameter

Front 27

French scale

Back 27

Developed by Charriere.
1 Charriere = 1 French = 0.33mm
Each consecutive French differs from the previous one by 0.33mm

Front 28

Catheter Shape

Back 28

The distal end of the catheter can be either straight or shaped and it is chosen depending on the vessel entered and the procedure being done. Specialized shapes are used for a variety of studies including entry into smaller vessels during angiography. Ex: pigtail, cobra, headhunter, visceral, etc

Front 29

Special catheter tips

Back 29

Some catheters are equipped with small balloons that occlude vessels, or baskets/forceps that allow the physician to remove foreign bodies or perform biopsies.

Front 30

Catheter torque

Back 30

response to twisting and turning, some catheters have steel mesh inside to increase torque ability

Front 31

Catheter memory

Back 31

Ability to retain the original shape inside the body.

Front 32

Catheter end-hole

Back 32

Used for administration of the contrast media into the vessel.

Front 33

Catheter side-holes

Back 33

Helps to reduce a possible whiplash effect. Side holes also increase the flow rate by 10-20% and aid in catheter stability.

Front 34

Pigtail Catheters

Back 34

Contain an end hole and multiple side holes. The curled tip helps to reduce the jet effect, preventing injury to the vessel. The curled end also assists in keeping the catheter in place.

Front 35

Highly Curved Catheters

Back 35

Designed for approach to sharply angled vessels. Designed for cerebral angiography and later for visceral angiography.

Front 36

Common Catheter Sizes

Back 36

Most vascular catheters are available in 5-7 French. Need to know the catheter size in order to determine which guide wire to use.