Glomus tumors of the skull base: combined use of MR angiography and spin-echo imaging.

PURPOSE

To evaluate the use of magnetic resonance (MR) angiography in the diagnosis of glomus tumors of the skull base.

MATERIALS AND METHODS

In 40 patients with pulsatile tinnitus, spin-echo (SE) images, single sections, and maximum intensity projections from gradient-echo sequences, including arterial MR angiography and MR venography, were evaluated for tumor detection. Interpretations by two independent observers were correlated with findings from histologic examination, digital subtraction angiography, computed tomography, and clinical follow-up.

RESULTS

Glomus tumors were detected near the tympanic plexus (n = 8) and close to the superior (n = 8) and inferior (n = 1) ganglia of the vagus nerve. Sixteen of 18 proved tumors were detected with SE images alone. Although four high-lying jugular bulbs were misinterpreted as tumor due to similar signal intensity, combined evaluation allowed differentiation between tumor and sinusal blood flow in all cases.

CONCLUSION

The authors recommend combined SE imaging and MR angiography for ruling out tumor in patients with pulsatile tinnitus.