Summary: He underwent a quick MRI search for a primary malignancy. Two
fast, coronal, large field-of-view sequences were performed: one
centered over the chest and one centered over the abdomen and
pelvis. It took 1 to 2 minutes to remove the head coil and center
the patient in the body coil. Each of the two sequences took <30
seconds. Overall, this added only a few minutes to the exam
time.
Diagnosis
Small cell carcinoma
Findings
The preliminary MRI obviously shows multiple unsuspected brain
metastases (Figure 1). The real question then is, "Where is the
primary carcinoma?" A fast whole-body screening sequence identified
a large lung mass in the right upper lobe with metastatic
adenopathy in the right hilum and right axilla (Figure 2A). The
abdomen and pelvis were grossly normal (Figure 2B).
With this information, a percu-taneous needle biopsy of the
palpable right axillary mass was performed without the need for
imaging guidance and without exposing the patient to the risk of
pneumothorax. Pathology was positive for small cell carcinoma.
Discussion
Occasionally, patients under-going brain or spine MRI are found
unexpectedly to have MR findings suggestive of metastases. The MR
technologists can usually recognize these findings. Our department
has recently developed a fast whole-body MRI screening sequence
that we run as a supplement to brain MRI of a patient who has been
discovered to have brain metastases. This has proven to be very
helpful and has added only a few minutes to the examination time.
In the case presented, we diagnosed the primary cancer, roughy
staged the cancer, and found a readily accessible biopsy site. If
this quick-search MR examination had been negative, we would have
proceeded with the standard procedure for an unknown primary
cancer, including chest X-ray, abdominal computed tomography (CT),
pelvic CT, and, if required, chest CT, mammography, barium enema,
and brain biopsy. In this case, fast whole-body MRI examination
obviated the need for these additional exams and procedures.
CONCLUSION
This case illustrates the benefit of fast whole-body MRI
sequences, which are helpful and can be performed easily and
quickly on high-strength magnets.1-4
Further investigation of these fast MRI screening techniques
should be considered to calculate the sensitivities and
specificities of the whole-body MR screening examination. When
brain or spine metastases are discovered unexpectedly, MR
technologists and radiologists should consider adding this
whole-body MRI screening sequence while the patient is still on the
MR table.
Prepared by Timothy J. Miller, MD from the
Department of Radiology, Good Samaritan Hospital, Cinncinnati,
OH.
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