Imaging-based evaluation of liver function: comparison of 99mTc-mebrofenin hepatobiliary scintigraphy and Gd-EOB-DTPA-enhanced MRI.

OBJECTIVES: To compare Gd-EOB-enhanced MRI and (99m)Tc-mebrofenin hepatobiliary scintigraphy (HBS) as imaging-based liver function tests for separate evaluation of right (RLL) and left liver lobe (LLL) function. METHODS: Fourteen patients underwent Gd-EOB-enhanced MRI and (99m)Tc-mebrofenin HBS after portal vein embolization within 24 h. Relative enhancement (RE) and hepatic uptake index (HUI) were determined from MRI; and T max, T 1/2 and mebrofenin uptake were determined from HBS, all values separately for RLL and LLL. RESULTS: Mebrofenin uptake correlated significantly with HUI and RE for both liver lobes. There was strong correlation of mebrofenin uptake with HUI for RLL (r (2) = 0.802, p = 0.001) and RE for LLL (r (2) = 0.704, p = 0.005) and moderate correlation with HUI for LLL (r (2) = 0.560, p = 0.037) and RE for RLL (r (2) = 0.620, p = 0.018). Correlating the percentage share of RLL function derived from MRI (with HUI) with the percentage of RLL function derived from mebrofenin uptake revealed a strong correlation (r (2) = 0.775, p = 0.002). CONCLUSIONS: Both RE and HUI correlate with mebrofenin uptake in HBS. The results suggest that Gd-EOB-enhanced MRI and (99m)Tc-mebrofenin HBS may equally be used to separately determine right and left liver lobe function. KEY POINTS: • Information about liver function can be acquired with routine Gd-EOB-MRI. • Gd-EOB-MRI and (99m) Tc-mebrofenin HBS show elevated function of non-embolized lobe. • Gd-EOB-MRI and (99m) Tc-mebrofenin HBS can determine lobar liver function.

Optimized separation of left and right liver lobe in dynamic (99m)Tc-mebrofenin hepatobiliary scintigraphy using a hybrid SPECT-CT scanner.

OBJECTIVE: To correctly display the left and right liver lobe separately on dynamic projection scintigraphy, it is essential to adjust the collimator to the angle of the plane between the two liver lobes. We propose an optimized protocol for separating left and right liver lobe in (99m)Tc-mebrofenin hepatobiliary scintigraphy in a hybrid SPECT-CT device. The protocol uses the inherent attenuation correction low-dose CT (AC-CT) for individually adjusting gamma camera head angulation. The results of this protocol are compared with hypothetical results based on previous MRI, fixed angle, and traditional frontal projection. METHODS: The absolute and relative degrees of overlapping volume between left and right liver lobe parenchyma for frontal projection, 45° right anterior oblique (RAO) projection, RAO angulation based on previously acquired MRI, and RAO based on the AC-CT were measured in 14 patients who underwent (99m)Tc-mebrofenin hepatobiliary scintigraphy. RESULTS: Relative degree of overlap was 31.3 ± 15.2 % for frontal projection, 8.2 ± 6.5 % for 45° RAO, 5.5 ± 3.5 % for RAO based on previous MRI, and 3.6 ± 2.5 % for RAO based on AC-CT. The relative overlap of RAO projections based on previous MRI was significantly lower than for frontal projection (p < 0.05). Use of the angle from the prior AC-CT, however, resulted in an even lower degree of overlap (p < 0.05). CONCLUSIONS: Performing (99m)Tc-mebrofenin hepatobiliary scintigraphy using RAO detector alignment with an angle derived from a prior CT obtained in the SPECT-CT scanner can significantly reduce the degree of overlap between right and left liver lobe. If SPECT-CT is not available, previous CT or MRI or a fixed angle of 45° may be used.

Multislice computed tomography using a triple-phase contrast protocol for preoperative assessment of hepatic tumor load in patients with hepatocellular carcinoma before liver transplantation.

For evaluation of triple-phase multislice computed tomography (CT) for assessment of hepatocellular carcinoma (HCC) before liver transplantation. All HCC patients who underwent liver transplantation at our institution between 2001 and 2006 and had contrast-enhanced abdominal 4-/16-slice CT [unenhanced, arterial (20 s delay), portal venous (40 s), and venous (80 s) scan] within 100 days before transplantation were enrolled retrospectively. CT data were reviewed by two observers. Results were correlated to histopathologic findings by means of a lesion-by-lesion evaluation. Thirty-two patients with 76 HCC-lesions were included. The lesion-based sensitivity of observer 1 and 2 was 78% (59/76) and 83% (63/76) (false positives, n = 6 and n = 10). The sensitivity of observer 1/2 was 89%/95% for lesions >20 mm (n = 37), 94% for lesions 11-20 mm (n = 18), and 43%/53% for lesions <10 mm (n = 21). The mean detection rates of unenhanced, arterial, portal venous, and venous phase scans were 30%, 74%, 59%, and 40%. All detected lesions were visible on arterial and/or portal venous scans (arterial only, 24%; portal venous only, 9%). Arterial and portal venous phase scans are the strongest contributors to the high detection rate of triple-phase multislice-CT in HCC. However, the detection of small HCC measuring <10 mm and false positive findings remains a challenge.