DOI:10.2214/AJR.05.0634
AJR 2007; 188:1026-1027
© American Roentgen Ray Society
Magnetite Ingested as a Nutritional Supplement: Unexpected Source of MRI Susceptibility Artifact
Ayako Taketomi-Takahashi1,
Yoshito Tsushima,
Takahito Nakajima,
Akie Takano,
Makoto Amanuma and
Keigo Endo
1 All authors: Department of Diagnostic and Interventional Radiology, Gunma
University Hospital, 3-39-15 Showamachi, Maebashi, Gunma 371-8511,
Japan.
Received April 12, 2005;
accepted after revision June 17, 2005.
Address correspondence to A. Taketomi-Takahashi
(ayakorad{at}med.gunma-u.ac.jp).
Keywords: abdominal imaging • MRI • safety
Introduction
Metallic objects inside the body are a known source of artifact in
MRI. Artifacts due to aneurysm clips
[1], screws, and microscopic
bits of metal from drill bits and suction tips
[2] have been reported.
However, reports regarding artifact due to substances intentionally ingested
by the patient are rare. We report the case of a patient in whom severe
susceptibility artifact was caused by magnetite (iron oxide
[FeFe2O4]) in powdered form intentionally ingested by
the patient for the sake of its alleged benefits as an iron supplement.
Case Report
A 44-year-old woman was referred to our institution for evaluation and
management of cervical cancer after receiving class V results of a
Papanicolaou smear and punch biopsy results with a pathologic diagnosis of
mucinous adenocarcinoma. She underwent MRI of the pelvis for staging of
cervical cancer. The patient reported no history of surgery or severe injury,
but scout images (gradient echo; TR/TE, 20/5; flip angle, 40°; matrix
size, 256 x 128; field of view, 400 mm; slice thickness, 10.0 mm) showed
extremely severe susceptibility artifact
(Fig. 1A). Because it was
thought unlikely that additional images would be of diagnostic quality, no
further MR images were obtained. The puzzled attending radiologist, after
confirming the patient had experienced no discomfort or local heat or pain,
ordered plain radiographs of the abdomen and found high-density material in
the bowel (Fig. 1B). On further
questioning, the patient somewhat reluctantly acknowledged regularly taking a
homeopathic iron supplement called Jiyou-tetsu, which she had purchased online
[3]. MRI was postponed for 1
week, during which the patient was instructed not to take Jiyou-tetsu, and
images of diagnostic quality were readily obtained
(Fig. 1C).
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Fig. 1A —44-year-old woman who ingested magnetite for nutritional purposes.
Scout gradient-echo image (TR/TE, 20/5; flip angle, 40°). Severe
susceptibility artifact is evident despite lack of clinical history of
previous laparotomy or severe trauma.
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Discussion
Susceptibility artifact caused by ferromagnetic material is a
well-established phenomenon. Artifact caused by aneurysm clips
[1], surgical screws, and
microscopic fragments caused by drill bits hitting suction tips
[2] have been reported to
degrade the diagnostic quality of images. Decorative tattoos and permanent
cosmetics have also been reported to cause artifact
[4] and, albeit rarely, pain
and burns [5].
Artifact caused by an alleged iron supplement intentionally ingested by the
patient is not a frequently reported occurrence. According to the Website
through which the patient purchased Jiyou-tetsu (the homeopathic iron
supplement in question), Jiyou-tetsu consists mostly of magnetite
(FeFe2O4) in powdered form. Instructions included with
purchase and available on the Website
[3] state 2-3 teaspoons daily
are recommended for people who believe their iron intake is insufficient. It
is suggested that the agent can be used to manage fatigue, anemia, menstrual
cramps, and morning sickness. We were able to purchase Jiyoutetsu quite easily
with no inquiries regarding symptoms or medical credentials. An MRI scout
image (Fig. 1D) of a gelatin
phantom containing a single grain of Jiyou-tetsu showed artifact similar to
that seen in our patient. Although our patient did not report any pain, local
heat, or burning sensation during imaging, the volume of magnetite ingested
makes it impossible to completely exclude the potential for complications.
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Fig. 1D —44-year-old woman who ingested magnetite for nutritional purposes.
Scout gradient-recalled echo image (17.0/5.0; flip angle, 40°) of gelatin
phantom containing single grain of Jiyou-tetsu shows severe susceptibility
artifact similar to that in A.
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Magnetite is not generally valued for its pharmaceutical properties in
modern Western medicine, but in traditional Chinese medicine, magnetite in
powdered form is called ci shi and is considered effective for
cardiac arrhythmia, emotional instability, and tinnitus. Interestingly, the
symptoms for which ci shi is considered effective are not generally
associated with iron deficiency anemia. Ci shi can be purchased
through Websites (some of which appear to originate in the United States)
specializing in alternative medicine and herbal remedies. We were not able to
obtain information regarding the amount of ci shi prescribed on a
routine basis.
In conclusion, magnetite intentionally ingested by the patient was found to
be the source of severe susceptibility artifact in the abdomen. Radiologists,
particularly those working in Asia or in areas with a large Asian population,
should be aware that magnetite is occasionally ingested for the sake of its
alleged health benefits.
References
- Grieve JP, Stacey R, Moore E, Kitchen ND, Jager HR. Artefact on MRA
following aneurysm clipping: an in vitro study and prospective comparison with
conventional angiography. Neuroradiology1999; 41:680
-686[CrossRef][Medline]
- Peterman SB, Hoffan JC Jr, Malko JA. Magnetic resonance artifact in
the postoperative cervical spine: a potential pitfall.
Spine 1991; 16:721
-725[CrossRef][Medline]
- [Site of purchase]
www.shichida-life.com
[in Japanese]. Available at
www.shichida-life.com/online/detail.php?id=84.
Accessed January 26, 2007
- Carr JJ. Danger in performing MR imaging on women who have tattooed
eyeliner or similar types of permanent cosmetic injections.
AJR 1995; 165:1546
-1547[Medline]
- Wagle WA, Smith M. Tattoo-induced skin burn during MR imaging.
AJR 2000; 175:1795
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Introduction
Case Report
