Does bone SPECT actually have lower sensitivity for detecting vertebral metastasis than MRI?
We compared the ability of bone SPECT and MRI to detect vertebral metastasis.


METHODS
Skeletal scintigraphy, including planar and SPECT imaging, and spinal MRI examinations, were performed in 22 cancer patients in whom a total of 88 metastatic foci and 12 degenerative joint disease lesions were detected. Metastatic foci were defined as lesions that suggested metastasis on MRI and/or bone destruction on radiographs or CT and/or aggravation of increased tracer uptakes on serial bone scans. Image reconstruction of axial, coronal and sagittal sections was processed in a 128 X 128 matrix. MRI studies were performed with a 1.5 tesla signal scanner using fast spin-echo sequences. T1- and T2-weighted images were obtained in the sagittal plane.


RESULTS
Twenty patients had at least one vertebral metastasis. MRI diagnosed 86 of the 88 (97.7%) metastatic foci; bone SPECT correctly diagnosed 81 of 88 (92.0%); and planar imaging detected 62 of 88 (70.4%). The two vertebrae with metastasis not detected by MRI were clearly seen by bone SPECT. Extra-vertebral body metastases (e.g. in the pedicle, lamina, transverse and spinous processes) were, however, most often detected by SPECT, followed by MRI and planar imaging (40 versus 32 versus 4).


CONCLUSIONS
Vertebral SPECT, using high-resolution SPECT equipment, produced excellent results that were comparable to and complementary with MRI in detecting vertebral metastasis. Our data suggest that vertebral SPECT is superior to MRI in detecting extra-vertebral body metastasis.
Kosuda
S
S
Department of Radiology, National Defense Medical College, Tokorozawa, Japan.
Kaji
T
T
Yokoyama
H
H
Yokokawa
T
T
Katayama
M
M
Iriye
T
T
Uematsu
M
M
Kusano
S
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013125:Spinal Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000556:secondary*; D013131:Spine / Q000000981:diagnostic imaging / Q000473:pathology; D015899:Tomography, Emission-Computed, Single-Photon