Ultrasound is usually the initial test that detects a suspected hemangioma. Follow up tests are used to confirm the diagnosis.
Here is an excerpt from: http://emedicine.medscape.com/article/177106-diagnosis
".# Accuracy of imaging studies
* The diagnostic capabilities of ultrasonography, Doppler color ultrasound, dynamic CT scan, and MRI were compared in a retrospective study of 27 patients with 35 hemangiomas.
* Sensitivities reported in the study were as follows:
o Ultrasonography – 46% sensitivity
o Combined B-mode and color Doppler ultrasound – 69% sensitivity
o Contrast-enhanced CT scan - 66% sensitivity
o T2-weighted MRI - 96% sensitivity
o Gadolinium-enhanced MRI combined with dynamic CT scan - 100% sensitivity
# Imaging of hemangiomas less than 2 cm
* Diagnostic accuracy diminishes for all imaging modalities when assessing a liver lesion that is less than 2 cm in diameter.
* MRI and 99mTc-RBC SPECT are the most accurate radiologic studies to establish the diagnosis of a small hepatic hemangioma.
# The authors continue to regard MRI as the diagnostic test of choice for hepatic hemangioma at most centers. Nuclear medicine studies may be used to confirm the diagnosis when a probable hemangioma is detected on ultrasonography. Nuclear medicine studies may also help to clarify the nature of a lesion when the diagnosis is equivocal on CT or MRI...."
It appears from this article that MRI is the test of choice.
Good luck,
Mike