Assessment of the vascularization of neuroendocrine tumors by stimulated acoustic emission of SHU 508A ultrasound contrast agent and color or power Doppler sonography

RATIONALE AND OBJECTIVES. To assess the vascularization of neuroendocrine t umors by stimulated acoustic emission (SAE) of SH U 508A during the blood p ool phase in comparison with contrast-enhanced Doppler sonography, METHODS. Thirty-six patients with neuroendocrine tumors received contrast-e nhanced Doppler sonography and 21, an additional SAE. To classify tumor per fusion on Doppler sonography, a 4-step rating score was introduced: (1) no vessels (hypoperfusion); (2) one feeding or central vessel (hypoperfusion); (3) some vessels (hyperperfusion); and (4) disseminated vessels (hyperperf usion), In 36 patients, 1 pancreatic primary tumor, 33 liver metastases, 1 splenic metastasis, and 1 lymph node metastasis were examined. Results were correlated with biphasic spiral CT (n = 35) and angiography (n = 2), RESULTS. Arterial-phase CT and digital subtraction angiography revealed 18 hyper- and 18 hypoperfused lesions. Contrast-enhanced Doppler correctly cla ssified 15 of 18 patients (83%) with hyperperfused lesions as well as 16 of 18 (89%) hypoperfused tumors by applying the rating score, SAE correctly i dentified 4 of 9 hyperperfused lesions (44%), 2 were isoperfused compared w ith normal liver tissue (22%), and 3 were hypoperfused (33%), Of 12 hypoper fused lesions, 11 were classified correctly (92%), and 1 showed isoperfusio n. Hence, the positive and negative predictive values for SAE were 80% and 69%, respectively. For contrast-enhanced Doppler sonography, positive and n egative predictive values were 88% and 84%, respectively. CONCLUSIONS. Blood pool SAE failed to determine subtle tumor perfusion corr ectly, The rating score for contrast-enhanced Doppler sonography characteri zed tumor perfusion with high accuracy, The use of a contrast agent signifi cantly improved perfusion characterization.