Bilal Tahir MD, Abstract Co-Author: Nothing to Disclose

Kumaresan Sandrasegaran MD, Abstract Co-Author: Grant, Koninklijke Philips Electronics NV, Cleveland, OH

Romil Saxena MD, Abstract Co-Author: Nothing to Disclose

Fatih Mustafa Akisik MD, Abstract Co-Author: Nothing to Disclose

Chandana G. Lall MD, Abstract Co-Author: Nothing to Disclose

Kyle Bertrand MD, Presenter: Nothing to Disclose

Raja Ramaswamy, Abstract Co-Author: Nothing to Disclose

Mary Maluccio MD, Abstract Co-Author: Nothing to Disclose

00030490-DMT et al, Abstract Co-Author: Nothing to Disclose

The diagnosis of hepatocellular cancer (HCC) is often made on imaging studies. Hypervascular lesions in cirrhosis that washout and are 1-2 cm (correlated on two imaging studies) or are over 2 cm (seen on one study) are considered HCC. We wished to evaluate the additional value of a 2-hour delayed imaging after intravenous gadobenate dimeglumine (MultiHance, Bracco, Princeton, NJ) in characterizing lesions in cirrhotic patients.

Retrospective review of MRI database from October 2004 to February 2009 revealed 282 cirrhotic patients with focal liver lesions. Patients without pathological confirmation (core biopsy or explant) or adequate follow up, without 2 hour delayed post-contrast study, and those with lesions > 5 cm, cystic lesions, or vascular invasion were excluded. This left 49 patients with histological confirmation of HCC and 9 patients with T2-hypointense nodules stable for at least 12 months (median follow up 32.5 months, range 12.6 to 128 months) who were considered to have regenerating / dysplastic nodules (RN). A total of 75 HCC [well-differentiated (WD HCC)=21, moderately-differentiated (MD HCC)=33, poorly differentiated (PD HCC)=21] and 27 RN were analyzed.

The typical appearance of HCC (hypervascularity and washout) was seen in 95% (20/21) of WD HCC, 70% (23/33) of MD HCC, 71% (15/21) of PD HCC, and 4% (1/27) of RN (p=0.02, Freidman test). The RN lesion that mimicked HCC was hyperintense on the 2-hour delayed phase but hyperintensity on delayed phase was also seen in a WD HCC. In lesions with atypical appearance for HCC, the only lesions that were hyperintense on the delayed phase were RN (n=11). 15 RN lesions were isointense on the delayed phase. Atypical HCC were isointense (n=5; 1 WD HCC, 4 MD HCC) or hypointense (n=12; 6 MD HCC, 6 PD HCC) on the delayed phase.

A 2-hour delayed gadobenate sequence is unlikely to be useful in lesions showing typical enhancement pattern of HCC. Atypical appearances are found in about 30% of MD HCC and PD HCC. In lesions with appearances that are atypical for HCC, a delayed scan may help in identifying those which are RN (hyperintense on delayed phase) or high-grade HCC (hypointense on delayed phase).

A 2-hour post-gadobenate MRI sequence may increase the diagnostic certainty when a < 5 cm atypically enhancing lesion is seen on the MRI (or CT) of a cirrhotic patient, obviating the need for biopsy.

Tahir, B, Sandrasegaran, K, Saxena, R, Akisik, F, Lall, C, Bertrand, K, Ramaswamy, R, Maluccio, M, et al, 0, The Usefulness of 2-hour Delayed Post-gadobenate Imaging in Characterizing Liver Lesions in Cirrhotic Patients.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8013874.html