Dedicated biphasic CT of liver lesions - is it definitive in diagnosing atypical hemangioma lesions?

On prior CTs, lesions were discovered looking like atypical hemangioma but not diagnostic.
3rd CT just done with dedicated biphasic CT confirms lesion as hemangioma so I no longer need any future follow up work ever

What's different with latest CT that's more definitive in the diagnosis?  On prior CTs with IV contrast, the issue with largest lesion was atypical appearance.  With dedicated biphasic CT, can one diagnose atypical hemangioma definitively? If so, why didn't they do biphasic CT first?

CT Report&lab test

HISTORY:  34 yr old M; incidental liver lesions, nonspecific by prior CTs

FINDINGS: Technique: Axial images of abdomen & pelvis obtained with IV administration of 120mL of Omnipaque 350. Delayed images of liver also performed. Comparison made to 12/13 &9/14/10

3 Liver lesions seen again, largest located in anterior right lobe, measuring 2.5x2.1cm. It displays peripheral puddling of contrast and on hepatic arterial phase, with gradual filling in to become homogeneously enhancing on delayed imaging. It enhances to greater degree than adjacent liver parenchyma on delayed imaging

11x9mm lesion in inferior right lobe is unchanged; displays peripheral puddling of contrast with gradual fill in on delayed imaging

3rd smallest lesion is 6mm and hypodense; too small to fully characterize

IMPRESSION
Largest lesion in anterior right lobe displays CT features most consistent with a hemangioma; 2nd 11mm lesion also displays features consistent with hemangioma

Lab data
Ferritin (22-322 ng/ml std range)  373 ng/ml (5/2011)
Transferrin sat (15-60% std range)  61% (5/2011)

ALT (<36 U/L):  41 (5/2011), 47 (12/2010), 48 (9/2010), 29 (3/2010)
AST (10-40 U/L):   24 (5/2011), 26 (12/2010), 22 (9/2010), 18 (3/2010)
All other tests normal

Prior CT
http://www.medhelp.org/posts/Liver-Transplant/Poorly-defined--hypodense--left-medial-segment-liver-lesion---Do-I-need-to-worry-about-cancer/show/1353219?personal_page_id=1799698#post_6182467

[Thomas D Schiano, MD]

..actually at our place triphasic CT scans are done.  next time a scan is done it can also be an MRI with eovist, which is a new contrast agent for the liver