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Thread: MRI for Syrnix / Metal Fragment Questions

  1. #1
    Senior Member ChesBay's Avatar
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    MRI for Syrnix / Metal Fragment Questions

    I have a bit of a strange problem related to a possible syrnix and getting a diagnosis...

    I was spinal cord injured in 1978 from a gun shot wound ( T2/T3).

    In the past few years I have had significant problems with chronic pain, sweats and some numbness in my hands. Until recently my doctors have explained my situation as par for the course for being twenty - five years post injury.

    I recently started seeing a different physiatrist. She seems to know her stuff. She gave me the most thorough neurological exam I have had in about twenty years. Based on the symptoms described above and the physical exam my physiatrist feels there is a good chance I may have a syrnix.

    I had a CT Scan done but the diagnostics folks said they could not rule out a syrnix without an MRI.

    Here is the problem... I was shot with a 22 caliber bullet. From the little I know about guns and a discussion with a ballistics expert the metallic fragments I have in my back are probably all lead. ( They did not remove the bullet from my back when I was injured.) They want to completely rule out the possibility of anything but lead and I would be able to get an MRI. ( if they are lead) If there is any metal they cannot do an MRI.

    I lived in Vermont when I was injured and the State crime victims advocate there has been attempting to find if there are any old reports on microfiche. She feels if there is are still reports there will be a ballistics report to answer the lead question. So far no luck with finding the report but they are still working on it and I am hopeful they will be able to find some answers so I can move forward on the problem.

    If there is no report I am stuck as far as I can see. I would really like to get an accurate diagnosis.

    Has anyone had a similar situation with metal being a deterrent to getting an MRI? Any ideas on an alternative method to get an accurate diagnosis on syrnix if I can't get an MRI?

    Thanks in advance,
    Paul

  2. #2
    Paul, let me give you a short answer. Your doctors are afraid that the magnetic field may move the fragments if they have iron in them or the fragments may be of the size and conductivity to heat up (like a microwave heats up metallic items). Bullets, shrapnel, or other metallic subtances are specific contraindications to MRI use in patients. I have done some back-of-the-envelope calculations and don't think that the magnetic field and the radiofrequency waves will be exert enough force or heat to move or heat up small bullet fragments. But, I doubt if this would persuade a clinician to put you into an MRI.

    The next logical step is a CT with contrast enhancement. This may be able to show the syrinx. An alternative is to simply do surgery. You may have tethering of the spinal cord to the dura. By the way, before MRI or CT imaging was available in the 1970's, doctors use to diagnose syrinxes by injecting dye intrathecally. It can still be done that way.

    Let me comment more later.

    Wise.

    [This message was edited by Wise Young on 04-27-03 at 03:33 PM.]

  3. #3
    Here is my longer commentary on the queston of whether MRI should be used in people who have bullets in the spine or spinal cord.

    Sawyer-Glover & Shellock (2000) wrote the following in the Journal of Magnetic Resonance Imaging 12:92-106:

    Furthermore, it is highly recommended that patients change into gowns or surgical scrubs to prevent clothing-related hazards (eg, metal objects become projectiles in the MR environment). However, this may not be feasible at some sites such as mobile MR systems due to space limitations. However, projectiles do pose a serious threat to the patient and those individuals accompanyingthe patient such as the MR radiologists, physicians,nurses, and other allied health personnel. A missed paper clip in a pants or shirt pocket, for example, could result in serious injury.

    A recent case example involved a subject with a large, flat metal hook on the pants that was hanging by asingle thread. While the patient was advanced into the1.5-T MR system, the hook was quickly pulled off the pants into the bore, passing over the face of the supinepatient. Denim jackets, pants and overalls often incorporate flat metal buttons that experience significant attraction to the static magnetic field of the MR system. These garments should be removed before any individual enters the magnet room.

    A complete pre-MRI procedure screening should optimally include three separate conversations with thepatient or any individual planning to enter the MR environment.The first interview takes place during the initial communication. Questions covered include major safety issues such as aneurysm clips, pacemakers, electronic implants, pregnancy, etc. This would take place at the scheduling of the appointment with the patient, the patient's physician, or the referring physician's office to prevent inappropriate scheduling of MR examinations.
    Given this type of recommendation, it is understandable why physicians are reluctant to put any body with potential ferromagnetic bullet fragments in the spinal cord into a magnetic resonance scanning machine. Some of the more modern machines with powerful 1.5 tesla magnets can indeed accelerate metallic objects into flying projectiles. The question is how likely the magnetic field would move small and probably bullet fragments that are not strongly ferromagnetic and are embedded in tissue.

    I did a literature search to see if there are any reported cases of magnetic resonance imaging of bullets causing problems. I came up with 10 relevant articles culled from 24 articles containing both "bullet" and "MRI" on Pubmed (Medline). The first and earliest paper on the subject by Ebraheim, et al. (1989) described a young woman who had a gunshot wound of the upper cervical spine. They used regular x-ray, CT scan, and MRI to image her spinal cord. Only the MRI demonstrated the relationship of the bullet and the spinal cord. The CT image was "obliterated by metal artifacts". The bullet was removed and the patient improved markedly after the surgery. During the 1990's, many patients with gunshot wounds probably have been scanned by MRI in various trauma centers in the United States. There has not been any reports of complications from use of MRI on such patients.

    In 1999, Barth Green (Finitsis, et al., 1999) dealt directly with the question whether the benefit of MR of the spine in the presence of metallic bullets is worth the risk. Between December 1991 and May 1996, 19 patients had retained metallic fragments in the region of the spine and had MR imaging at the University of Miami. Metallic fragments were present in the cervical spine of 6 patients, thoracic spine in 8 patients, and thoracolumbar and lumbar in 5 patients. Fifteen of the patients had bullet fragments larger than 1 cm (mean 1.5 cm) with four with fragments inside the spinal canal (<0.4 cm), six in the spinal bone, and five in the paraspinal region. The imaging was carried out at 1 month to 6 years after injury, using either a 1.0 or a 1.5 tesla machine. The imaging led to surgical intervention in 3 of the 19 patients and no untoward effects were seen. Finitsis, et al. concluded: "we support the use of MR imaging for patients with retained metallic fragments in the region of the spine; the information we gained would have been difficult to obtain with other imaging techniques."

    This Finitsis article aroused a strong critique from Emanuel Kanal, Director of Clinical and Education MR at the University of Pittsburgh. He thought that the study was inconclusive. He reminded readers that experience with 19 patients is not sufficient for such a sweeping conclusion, that exposure of such patients to the MR environment is "fraught with peril" and "not scientifically sound". He pointed out one case of a patient who suffered an intraocular hemorrhage and unilateral blindness after inadvertent exposure to a 0.35 T scanner and subsequently found to have a 2-3 mm fragment in the retina. He gave another example of a patient with an aneurysm clip but the clip was seen in an initial scan and the patient did not have any problems. He argues for cautious weighing of the risks and benefits and that all the variables should be considered, including whether the fragment is anchored to bone. In his response, Barth Green agreed that risk-benefit ratios should always be considered on an individual basis, that scientifically sound methods had not been applied (no control, no followup, and no attempt to detect subclinical changes). He, however, pointed out that neurosurgeons deal with hundreds of gunshot induced spinal cord injury and "have never seen any evidence of bullet movement and, more important, neurological deterioration associated with MR scanning at 1.5 T or below."

    A number of other clinicians agree with Barth Green. Hess, et al. (2000a) pointed out that the general opinion that MR should not be used if there was a metallic foreign body is "not universally valid". They report a case of MR imaging of an intraorbital (where the eyeball is situated) bullet, showing that MR actually allows high-resolution illustration of the tissue damage and is far superior to CT scans. In another paper, Hess, et al. (2000b) tested a total of 56 different bullets for ferromagnetism and MR imaging quality in vitro and in pig carcasses with a commercially available 1.5-MRI scan. While ferromagnetic bullets did interfere with MR imaging, a majority of the bullets did not and produced very clear tissue images. Smugar, et al. (1999) at Thomas Jefferson Hospital in Philadelphia evaluated 19 patients who had bullets adjacent to the spinal cord or roots. The patients were queried during the scanning and followed for 2-24 months. No patient experienced pain or discomfort from the procedure. Followup radiographic studies showed no bullet movement. They concluded that MRI may be carried out in patients with intraspinal bullets. Incidentally, MR imaging is routinely used by pathologists to visualize bullets in cadavers (Oehmichen, et al., 2003) and there has been no report of movement of the bullet associated with exposure to the MR field.

    So what is the basis of the fear of placing patients who have retained bullet fragments into the magnetic resonance environment? The fear comes from two studies in the early 1990's. Smith, et al. (1990) evaluated the effects of magnetic resonance imaging on 28 missiles that covered the range of bullet types and materials suggested by the Cleveland Police Department. The put the bullets into a gelatin that mimicked the mass and consistency of brain and measured the temperature of the bullets after an hour of MR imaging. They found that exposure to the MR field deflected all steel-containing bullets, except for the Winchestor armor piercing 38 caliber. One non-steel 7.38-mm Mauser bullet also deflected. The deflection force varied substantially from 514 to 15,504 dynes. However, there was no significant temperature changes. Teitelbaum, et al. (1990) examined the ferromagnetism of various bullets and shotgun pellets. They found marked magnetic deflection in 4 of 21 types of bullets. Three of the four were made outside of the U.S. Two were known to contain steel while the other two were reputedly copper or copper-nicket-jacketed lead bullets.

    It seems to me that a reasonable compromise is to do a short scan in a small field, i.e. 0.5 T, magnetic resonance machine. If there is any ferromagnetic tendency of the bullets, it will be very apparent in the images. There is no point to going on ahead if the bullets have ferromagnetic tendencies because the MR image would not be very useful. However, if the low resolution scan show no interference by the bullet, it would then be safe to apply MRI to the patient. I think that there is sufficient data suggesting that MR imaging is very safe with non-ferrous bullets.

    Literature Cited

    • Ebraheim NA, Savolaine ER, Jackson WT, Andreshak TG and Rayport M (1989). Magnetic resonance imaging in the evaluation of a gunshot wound to the cervical spine. J Orthop Trauma 3:19-22. Summary: A patient in the second trimester of pregnancy sustained a gunshot wound of the upper cervical spine with a partial Brown-Sequard syndrome. The patient's condition was evaluated by conventional roentgenography, computed axial tomography (CT), and magnetic resonance imaging (MRI). The MRI alone clearly demonstrated the relationship of the bullet and the spinal cord, whereas the CT image was obliterated by metal artifacts. The bullet was removed from the spinal canal by a posterior approach with the patient in the sitting position and in skeletal cervical traction. The neurological status of the patient improved markedly after the surgery. Department of Orthopaedic Surgery, Medical College of Ohio, Toledo 43699.
    • Finitsis SN, Falcone S and Green BA (1999). MR of the spine in the presence of metallic bullet fragments: is the benefit worth the risk? AJNR Am J Neuroradiol 20:354-6. Summary: http://www.ajnr.org/cgi/content/full/20/2/354
    • Hess U, Harms J, Lanzl I, Wilhelm T and Grafin von Einsiedel H (2000a). [The radiological diagnosis of an intraorbital bullet projectile]. Radiologe 40:404-7. Summary: Beside conventional X-ray examination, ultrasound and computer tomographic examination are accepted radiologic techniques to assess the extend of damage of intraorbital injuries. With the exception of a few reports in the literature there is agreement that intraorbital metallic foreign bodies and gun-shot bullets represent a contraindication for magnetic resonance (MR) imaging examination because of artificial imaging side effects and the potential of secondary dislocation of the metallic foreign body due to ferromagnetism. By means of the case reported here it is shown that this general opinion is not universally valid. Depending on the elemental metallic composition of foreign bodies and gun-shot bullets it is demonstrated that MR examination allows high-resolution illustration and in some cases is advantageous compared with other radiologic imaging techniques. Abteilung Neuroradiologie, Technische Universitat Munchen, Klinikum rechts der Isar.
    • Hess U, Harms J, Schneider A, Schleef M, Ganter C and Hannig C (2000b). Assessment of gunshot bullet injuries with the use of magnetic resonance imaging. J Trauma 49:704-9. Summary: BACKGROUND: Magnetic resonance imaging (MRI) is rarely used for preoperative assessment of shotgun injuries because of concerns of displacing the possibly ferromagnetic foreign body within the surrounding tissue. METHODS: A total of 56 different projectiles underwent MRI testing for ferromagnetism and imaging quality in vitro and in pig carcasses with a commercially available 1.5-MRI scan. Image quality was compared with that of computed tomographic scans. RESULTS: Projectiles with ferromagnetic properties can be distinguished easily from nonferromagnetic ones by pretesting the motion of an identical projectile within the MRI coil. When ferromagnetic projectiles were excluded, MRI yielded the more precise images compared with other imaging techniques. Projectile localization and associated soft tissue injuries were visualized without artifacts in all cases. CONCLUSIONS: When ferromagnetic foreign bodies are excluded by pretesting their properties within the MRI with a comparative projectile, MRI portends an excellent imaging procedure for assessing the extent of injury and planning the removal by surgery. Department of Diagnostic Radiology, Klinikum rechts der Isar, Technische Universitat Munchen Ismaningerstrasse, Munich, Germany.
    • Oehmichen M, Gehl HB, Meissner C, Petersen D, Hoche W, Gerling I and Konig HG (2003). Forensic pathological aspects of postmortem imaging of gunshot injury to the head: documentation and biometric data. Acta Neuropathol (Berl) Summary: To determine the value of imaging procedures such as computer tomography (CT) and magnetic resonance imaging (MRI) of the head in providing additional information of forensic relevance, we examined 17 cadavers of human victims of gunshot wounds to the head. Three of the victims briefly survived the gunshot wound. The weapons involved were all guns with low muzzle energy (<550 J), i.e., handguns and low-velocity rifles. In the majority of cases [ n=15) a penetrating wound to the head was found, only two cases showed the bullet lodged in the brain. In some cases, imaging of the skull and brain was performed prior to autopsy; in others imaging took place after autopsy on the isolated, formalin-fixed brain. The imaging findings were correlated with the criminological data and the results of macroscopic and microscopic examination of the brain. The findings on the bony structures of the head provided imaging criteria for differentiation between entrance and exit of the gunshot wounds, which corresponded to the forensic pathological findings at autopsy. CT scans and MRI of the cerebral parenchyma revealed lanes of opaque bone and missile fragments along the course of the missile, which allowed recognition of the missile track in 3D reconstruction. Biometric reconstruction allowed easy determination of the angle of the missile track in all three planes. Examination of the parenchymal structures and imaging of the isolated, formalin-fixed brain enabled tracking of the missile path directly along the zone of destruction as well as demonstration of secondary changes such as air bubbles along the bullet course, hemorrhage and edema. The significance of a translucent zone surrounding the missile track in several cases remains unclear; it probably represents tissue destruction secondary to temporary cavitation. The imaging procedures described here allowed excellent documentation of in situ conditions, while the storing of data enabled biometric reconstruction for determination of the angle of trajectory, of entrance and exit wounds, and the extent of tissue damage along the missile track and, possibly, in the zone of temporary cavitation. Institute of Legal Medicine, University Hospital Schleswig-Holstein, Campus Lubeck, Kahlhorststrasse 31-35, 23562, Lubeck, Germany.
    • Smith AS, Hurst GC, Duerk JL and Diaz PJ (1991). MR of ballistic materials: imaging artifacts and potential hazards. AJNR Am J Neuroradiol 12:567-72. Summary: The most common ballistic materials available in the urban setting were studied for their MR effects on deflection force, rotation, heating, and imaging artifacts at 1.5 T to determine the potential efficacy and safety for imaging patients with ballistic injuries. The 28 missiles tested covered the range of bullet types and materials suggested by the Cleveland Police Department. The deflection force was measured by the New method. Rotation was evaluated 30 min after bullets had been placed in a 10% (weight per weight) ballistic gelatin designed to simulate brain tissue, with the long axis of the bullet placed parallel and perpendicular to the Z axis of the magnet. Heating was measured with alcohol thermometers by imaging for 1 hr alternatively with gradient-echo and spin-echo sequences (RF absorption = 0.033 and 0.326 w/kg respectively). Image artifacts on routine sequences were evaluated. All the steel-containing bullets except for the Winchester armor-piercing 38 caliber exhibited deflection. A nonsteel 7.38-mm Mauser also deflected. Deflection range was 514 to 15,504 dynes. Rotation occurred when the bullets were not parallel to the Z axis. Temperature changes were not significant. Deflecting projectiles resulted in obliteration of the image. The artifacts from other projectiles were small but varied by content. The artifact of the Winchester armor-piercing 38-caliber bullet was similar to those without steel. Bullets that contain steel or ferromagnetic contaminates such as nickel can be rotated within the MR unit.(ABSTRACT TRUNCATED AT 250 WORDS). Department of Radiology, MetroHealth Medical Center of Cleveland, Case Western Reserve University 44106.
    • Smugar SS, Schweitzer ME and Hume E (1999). MRI in patients with intraspinal bullets. J Magn Reson Imaging 9:151-3. Summary: The purpose of this study was to determine whether neurologic sequelae occur in patients with intraspinal bullets or bullet fragments who undergo magnetic resonance imaging (MRI). Nineteen patients with bullets or bullet fragments adjacent to the cord or nerve roots underwent clinical MRI studies at 1.5 T. Sequences included conventional spin echo, fast spin echo, gradient-recalled echo, and inversion recovery. Patients were queried during scanning for symptoms of discomfort, pain, or change in neurologic status. Detailed neurologic examinations were performed prior to MRI (baseline), post MRI, and at the patients' discharge. Sixteen patients were completely paralyzed (ASIA-A), and three were not paralyzed. The length of time from injury was 2-24 months. No patients experienced pain or discomfort during the procedure. No change in neurologic status occurred. Follow-up radiographic studies showed no bullet movement following the scanning. We conclude that in patients with complete spinal cord injury, MRI in patients with intraspinal bullets may be performed. Department of Radiology, Thomas Jefferson University Hospital, Philadelphia, PA 19107, USA.
    • Teitelbaum GP, Yee CA, Van Horn DD, Kim HS and Colletti PM (1990). Metallic ballistic fragments: MR imaging safety and artifacts. Radiology 175:855-9. Summary: The ferromagnetism of various bullets and shotgun pellets was tested in vitro. Magnetic deflection showed that four of 21 metallic specimens tested (all bullets) demonstrated marked ferromagnetism. Three of these four were made outside the United States; two of the four were known to contain steel, and the other two were reportedly either copper or copper-nickel-jacketed lead bullets (indicating that the ferromagnetism was due to impurities in the bullet jackets or cores). Ferromagnetic bullets readily rotated within a gelatin phantom in response to magnetic torque. Nonferromagnetic bullets and pellets demonstrated only mild to moderate metal artifact during spin-echo and gradient-echo magnetic resonance (MR) imaging. However, all four of the ferromagnetic bullets produced severe MR artifacts and image distortion. MR studies of seven patients with retained bullets, pellets, or shrapnel were reviewed. In six of the seven, only mild MR artifacts were seen. Only intracranial shrapnel (presumably steel) in one patient created significant artifact. All seven patients with retained bullets and shotgun pellets were imaged safely with MR. However, caution should be exercised with MR imaging in the presence of metallic foreign bodies, particularly if they are located near vital neural, vascular, or soft-tissue structures. Department of Radiology, LAC-USC Medical Center 90033.

    Attachment: Finitsos article (PDF format) is attached along with reviewer's response
    Attached Images Attached Images

  4. #4
    Senior Member ChesBay's Avatar
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    Wise,

    Thanks so much for your thoughtful and highly informative responses.

    You have helped me understand the situation quite well.

    I plan to print out material and discuss possible options with my physiatrist and MRI diagnostic center.

    Again many thanks for your hard work,
    Paul

  5. #5

    Lightbulb MRI's and bullet fragments

    June 20th, 2012

    Hello, I just got home from the hospital where I had two (lumbar & cervical) MRI procedures today. With and without contrast. I have have 3 or four MRI's in the past.

    I was shot eight times with a handgun April 29, 1968; these were lead bullets. They did not remove most of the lead that was left in my body; I have fragments in my head, face, right thigh & femur, left hand, and in various places in my back. They did remove one almost intact bullet that was only slightly damaged -- from the back of my neck, it entered my face.

    I have had NO problems related to having the MRI's. I found this site researching lead bullets/fragments in the body and MRI's.

    Good luck all that may have a similar situation, all I can say is this is MY experience. I am having problems that in my opinion are stemming from having the bullets and fragments in my body; the MRI's are very much helping to locate these, and hopefully will help find a solution.

    Cheers all.

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