MRI Compatibilty of Flotec's Flopac


7625 West New York Street
Indianapolis, Indiana 46214-4911 USA
Telephone: (317) 273-6960
Facsimile: (317) 273-6979
Order Desk Telephone: (800) 401-1723
Order Desk Facsimile: (800) 515-9254
E-mail: info@floteco2.com
Home Page	Technical Bulletins

Magnetic attraction is a critical factor in MRI (Magnetic Resonance Imaging) equipment. MRI medical scanning systems utilize magnets that are so powerful they can pull steel and other ferrous metal items across the room into the magnet. It is of the utmost importance that the magnetic attractions of any items within the magnet’s field of influence fall within the acceptable standard.

For patients on oxygen therapy undergoing MRI examination, an MRI compatible and safe regulator / cylinder combination offers the added convenience of allowing the portable oxygen delivery system to remain with the patient rather than having to resort to the use of a lengthy oxygen cannula as a magnetic regulator and cylinder must be secured well outside of the magnetic field.

The use of MRI compatible and safe portable oxygen delivery systems must ensure the safety of both patient and caregiver as non-magnetic systems pose no physical safety concerns, as well as offer no interference in the performance of the device nor of the MRI scanner itself.

This can be accomplished if the pressure regulator and cylinder are constructed of non-magnetic materials such as aluminum or some aluminum alloys, brass and non-magnetic stainless steel.

Flotec manufactured oxygen medical gas regulators (including Flopac) are constructed utilizing materials such as these; e.g... aluminum-alloy regulator body, flow meter body, and liter flow selector knob as examples.

Our Flopac™ integrated regulator / cylinder system’s manual pressure shut-off knob and flange plate washer are machined using the same aluminum-alloy.

Other Flopac™ component parts include a solid Brass tri-metal plated connector module, socket hex cap screw, check-valve body, retainer, piston, manifold, poppet, and shim-cup rotor.

However, this regulator is not constructed entirely of aluminum-alloy and brass. Some critical component parts of Flotec regulators are made of “non-magnetic” stainless steel such as the springs, shims, detent balls, roll pins, and the Flopac’s external carry handle.

Flotec oxygen pressure regulator, Cat. # RR810-310H1, s/n 421763, was submitted for deflection testing to Emanuel Kanal, MD, FACR, Director, MR Services UPMS Presbyterian, 200 Lothrop Street , Department of Radiology, Pittsburg , PA 15213-2582 .

This Flotec oxygen regulator was also tested for torque and artifact generation potential. All testing was performed in a GE Signa® LX 3.0T MR System. Specifications of this System are included in our Technical Bulletin “MRI (Magnetic) Safety & Compatibility of Flotec Aluminum Regulators”

This Flotec oxygen regulator was tested with a hand held magnet prior to flow rate accuracy measurements and function testing being performed. No gross ferromagnetic attraction was noted with the oxygen regulator when exposed to this relatively weak hand held magnet.

Accuracy of flow measurements were examined on this Flotec regulator in two separate locations:

b) Location #2 at the entrance to the magnet room (approximately 33 feet from the magnet bore opening.

Flotec oxygen pressure regulator, Cat. # RR810-310H1, s/n 421763 demonstrated 21 degrees of deflection on the deflection angle test. This was below the 45-degree maximum threshold established for claims of MRI safety.

Further, no alteration of flow rate / function was identified or observed for this oxygen Regulator

The Flotec Oxygen Aluminum-Alloy Pressure Regulator is MRI Safe and MRI Compatible.

The Flopac™ Oxygen Pressure Regulator examined, Cat. #FP4- XX- B05- 7105T2 utilizes many of the same internal component parts as Cat. # RR810-310H1, s/n 421763 which was formally tested.

The differences between Flopac™ Pressure Regulator FP4-XX-B05-7105T2 and the formally tested Flotec Oxygen Pressure Regulator are as follows:

a) Flopac™ pressure regulator is valved directly onto an Aluminum or Composite Oxygen cylinder.

(The formally tested Flotec RW series yoke style regulator was connected via a standard MRI Compatible Cylinder Post valve)

b) Flopac™ pressure regulator utilizes an InGage™ series oxygen regulator incorporating an internal contents pressure gauge with all brass high-pressure bourdon tube.

(The formally tested Flotec RW series yoke style regulator uses an externally threaded standard high pressure gauge and rubber boot)

c) Flopac™ pressure regulator utilizes a special all brass high-pressure inlet

connector module with manual cylinder pressure on /off valve and CGA 540 check valve port for venting, vacuuming and transfilling. This module is threaded directly onto the cylinders access orifice.

(The formally tested Flotec RW Series yoke style regulator attaches onto a standard CGA-870 cylinder post valve)

d) Flopac™ pressure regulator utilizes a specially designed burst disk integrally incorporated into the connector module.

(The formally tested Flotec RW series yoke style regulator utilized the standard cylinder post valve burst disk)

Flopac™ Oxygen Pressure Regulator was tested with a 3200 Gauss hand held magnet. No gross ferromagnetic attraction was noted with the Flopac regulator when exposed to this hand held magnet.

a) Flopac™ oxygen pressure regulator Stainless Steel “on-off valve stem” is

b) Flopac™ oxygen regulator Stainless Steel “Halo Handle” is non- magnetic.

c) Flopac™ oxygen regulator CGA-540 check-valve hex nut (weight: 1.39g) demonstrates minimal magnetic characteristics easily compensated by the mass and weight of the entire device.

d) Flopac oxygen regulator on-off valve lock-washer (weight: 0.3g) demonstrates minimal magnetic characteristics easily compensated by the mass and weight of the entire device.

The Flopac™ Oxygen Pressure Regulator, Cat. # FP4-XX-B05-7105T2, exhibits equal to or less than the degree of ferromagnetic attraction as compared with the formally tested and previously approved Flotec aluminum RW series oxygen yoke style regulator Cat. # RR810-310H1 s/n 421763.

As Flopac™ is only labeled as MRI Compatible and Safe when utilized in conjunction with a corresponding Aluminum or Composite cylinder, the cylinders’ additional weight further ensures that no ferromagnetic potential is present.

Therefore, Flopac™ meets the criteria for both MRI safety and MRI compatibility.

As notated under “conclusions” in the formal testing report, grossly detectable Lenz’s Law related forces when torqued at bore entry and at magnet isocenter are expected and should not be misconstrued as affecting present definitions of product labeling.